SlideShare a Scribd company logo
1 of 7
Download to read offline
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1193
Smart Ladder: A Survey
Tareek Pattewar1, Megha Surywanshi2, Ankita Chaure3, Harshal Chaudhari4 , Priyanka Patil5
Anushka Bedse6
1Assistant Professor, Dept. of Information Technology, R. C. Patel Institute of Technology, Maharashtra, India
2, 3,4,5,6Student, Dept. of Information Technology, R. C. Patel Institute of Technology, Maharashtra, India
---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract -Now a days ladders are important and
essential tools that are used widely in a variety of
industries. A ladder is a piece of equipment consisting of a
series of bars or steps between two upright lengths of wood,
metal or rope used for climbing up or down
something. They help us move up and down and work at
different heights. Portable ladders, in particular, are useful
tools because they can be readily moved or carried. They are
simply built and come in many sizes, shapes and styles.
Key Words: Hydraulic cylinder, Pulley, Microcontroller,
Belt, Lock, Battery, Motor.
1. INTRODUCTION
1.1 Different type of mechanism:
1. Hydraulic Scissor ladder:
“The machine which is achieved desired height by the
using of linkages, folding support in the scissor form is
known as scissor mechanism.” A scissor ladder mechanism
is a device used to extend or react a platform by hydraulic
means. The extension and or displacement motion is
achieved by application of force by hydraulic cylinder to
one or more support. This forces results is an elongation of
the cross pattern. Retraction through hydraulic cylinder is
also achieved when lowering of platform is desired. A
scissor life table has many useful purposes. The
applications of a scissor lift table include a variety of
things, but the platform is ultimately designed to help lift
and raise heavier objects. The industrial lift is most often
seen in behind the scenes of retail establishments and
warehouses, although manufacturing engineers are always
redesigning the lift for various uses like lifting heavy loads.
A hydraulic scissor lift is a mechanical device used for
various applications for lifting of the loads to a height or
level [1]. A lift table is defined as a scissor lift used to
stack, raise or lower, convey and/or transfer material
between two or more elevations
Fig1. Hydraulic Scissor ladder [1]
2. Automatic Loft / Attic Ladder:
An attic ladder (US) or loft ladder (UK) is a
retractable ladder that is installed into the floor of
an attic and ceiling of the floor below the attic. They are
used as an inexpensive and compact alternative to having
a stairway that ascends to the attic of a building. They are
useful in areas with space constraints that would hinder
the installation of a standard staircase. Attic ladders
typically consist of a ladder with wider steps and a steep
slope.[1] A drawstring will hang down to allow the ladder
to be manually extended. Attic ladders are usually made of
wood, metal, aluminum. The fire departments carry attic
ladders on fire apparatus for use to locate and extinguish
fires in attic spaces. They are in a single ladder that is
often used by firefighters for interior attic access and have
hinged rungs, which allow them to be folded inward so
that one beam rests on the other, with the rungs hidden
away in the middle[7]. This compatibility allows it to be
carried in attic scuttle holes, narrow passageways, and
small rooms or closets.
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1194
Fig2. Automatic Loft / Attic Ladder [7]
3. Rotary car parking system:
It is simple to operate with the driver parking and leaving
the vehicle in the system at the ground level. Once the
driver leaves the incorporated safety zone the vehicle is
automatically parked by the system rotating to lift the
parked car away from the bottom central position. This
leaves an empty parking space available at the ground
level for the next car to be parked on. The parked car is
easily retrieved by pushing the button for the relevant
position number the car is parked on. This causes the
required car to rotate down to ground level ready for the
driver to enter the safety zone and reverse the car out of
the system [14].
Fig3. Rotary car parking system
4. Automatic Liquid filing mechanism horizontal
ladder:
Nowadays with many industrial applications, a conveyor
system is used to move object from one location to
another effective way to reduce losing time and effort and
it is very useful in packaging process. A conveyor system
has several forms but in this paper, a Flat belt type is used
to move the bottles as shown in Fig. (4). Conveyors are
especially useful in applications which including the
transportation of heavy or large materials. A Flat belt
conveyer has a dimensions of (120*70*30) cm the belt is
made from elastic material [15]. Six pulleys a distributed
along the belt, the first one rotates with the rotation of
motor shaft and it usually called drive pulley and the other
five pulley called idler pulley.
Fig4.Automatic liquid filling ladder [15]
5. Ladder Automatic Vending Machine:
During this industrialization vending machines play an
important role for fulfilling the process immediate needs
of the society. In a challenge to competitive industrial
world, a system must be flexible, efficient and cost
effective; so automation in machines is very much
essential. When to design a program under which
whenever a user’s insert 5 rupees coin it will dispense tea
and for 10 rupees coin it will dispense coffee and also
count the number of coffee and tea served for the time. It
requires a PLC Brand and model of SIEMENS S7 SERIES
312, IFM Communication and SIMATIC Manager [16].
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1195
Fig5. Automatic vending machine ladder [16]
2. LITREATURE SURVEY
1. Jaydeep et.al Design And Kinematic Analysis Of
Gear Powered Scissor Lift Conventionally a
scissor lift or jack is used for lifting a vehicle to
change a tire, to gain access to go to the underside
of the vehicle, to lift the body to appreciable
height, and many other applications Also such lifts
can be used for various purposes like
maintenance and many material handling
operations. It can be of mechanical, pneumatic or
hydraulic type. The design described in the paper
is developed keeping in mind that the lift can be
operated by mechanical means so that the overall
cost of the scissor lift is reduced. Also such design
can make the lift more compact and much suitable
for medium scale work. Finally the analysis is also
carried out in order to check the compatibility of
the design values [2].
2. Gaffar G Momin, Rohan Hatti, Karan Dalvi, Faisal
Bargi, Rohit Devare,et.al,have proposed Design
Manufacturing Analysis of Hydraulic Scissor Lift,
In their paper they have discussed about is mainly
focused on force acting on the hydraulic scissor
lift when it is extended and contracted. Generally,
a hydraulic scissor lift is used for lifting and
holding heavy weight components. Material
selection plays a key role in designing a machine
and also influence on several factor such as
durability,reliability, strength. [1].
3. Karan Dalvi Design, et.al Manufacturing Analysis
Of Hydraulic Scissor Lift is a simple mechanical
device used to raise element or object from
ground level to a certain height to perform a
specific work with maximum load and minimum
efforts. This project describes the design as well
as analysis of a mechanical scissor lift which
works on the principle of screw jack. The design
will be developed keeping in mind that the lift can
be operated by mechanical means so that the
overall cost of the scissor lift is reduced [3].
4. Todd J. Bacon designed a belt-driven
transportation system including a first set of
pulleys rotatable attached to a second member
and a second set of pulleys rotatable attached to a
second member. The first and second members
have relative movement to each other .The system
further includes a unitary belt that is guided
through a path defined by the first and second
sets of pulleys. A plurality of range members
maintain a proper positioning of the belt on the
pulleys. [4].
5. Dong et al described that the tip-over of scissor
lifts in operation has frequently resulted in the
death and/or severe injuries of workers. Two
series of experiments were performed under
possible tip-over scenarios: curb impact and
pothole depression. The results suggest that the
lift should not be elevated on largely deformable
and/or uneven surfaces such as bridged wood
board or a soft soil base. The worker on the lift
platform should avoid any large continuous
periodic movement or forceful action in the
horizontal plane, especially when the lift is fully
elevated. Besides the tilt angle of the lift, the tilt
speed should be monitored to help prevent the
tipover. [5].
6. Richard et al developed a scissor lift apparatus
that has three scissor units for supplying heavy
1oads. A central Scissor unit has its arms located
inwardly of the immediately lower and upper
scissor units, and folds into the upper and lower
scissor units for storage within a chamber in a
mobile chassis The scissor arms of the upper and
lower scissor units includes rectangular box
beams with a great vertical than horizontal
dimension. Hydraulic cylinders are located within
and coupled to the opposite two arms of the
center scissor unit to expand and collapse the
same. [6].
7. Divyesh Prafulla Ubale, et al. The conventional
method of using rope, ladder lift getting person to
a height encounter a lot of limitation (time and
energy consumption, comfortability, amount of
load that can be carried etc.) also there may be a
risk of falling down in case of ladders hence
hydraulic scissors lift is designed to overcome all
these difficulties. The main aim of this paper is
design and analysis and to construct a multiutility
home equipment for senior citizens so that they
can carry their daily activities efficiently. Also the
equipment should be compact and cost effective.
Lifting height achieved by scissor mechanism is of
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1196
1 m from bottom level. Buckling and bending
failure analysis of scissor is also done in this
paper. With ceaseless development of science and
technology, more and more new technologies are
applied to lifting appliance design. This project
aims at making equipment multifunctional, easy
to use/operate, cost effective and portable so that
it will be used conveniently at home and may be
used in hospitals, hotels and other common
places. Senior citizens face many problems to
carry out their day to day activities, as this
equipment is designed in such a way that (e.g. it is
remote operated with battery) they can easily
move in house and perform day to day activities.
All safety considerations are taken into account
while designing equipment. Scissor lifting
mechanism is designed to lift person to desired
height. A scissor lift mechanism is a device used to
extend or retract a platform by hydraulic means.
The Extension or displacement motion is achieved
by the application of force by hydraulic cylinder to
one or more supports. This force results in an
elongation of the cross pattern. Retraction
through hydraulic cylinder is also achieved when
lowering of platform is desired [8].
8. S. B. Naik, et al A special type of beam lifting
device is designed for textile industries. The
machine is hydraulically operated and is having
two frames one horizontal and another vertical.
Horizontal frame is mounted with two telescopic
cylinders used for beam lifting to required height.
The mobility for the structure is provided by
using castor wheels. Finite element analysis of the
frames is done by ANSYS software considering the
need of the textile industries, a special purpose
machine has been designed to lift the beams in
textile industries. The finite element analysis of
the frame of this machine is done to get the idea of
the stresses & deformation of the structure in
order to modify the same if needed [10].
9. M. Abhinay, P.Sampath Rao Aerial scissor lifts are
generally used for temporary, flexible access
purposes such as maintenance and construction
work or by fire-fighters for emergency access, etc
which distinguishes them from permanent access
equipment such as elevators. They are designed to
lift limited weights usually less than a ton,
although some have a higher safe working load
(SWL). The increasing demand of Aerial Scissor
Lifts in companies in order to improve their
manufacturing flexibility and output by providing
variable height access to their work. This is
especially true when the work being accessed is
raised off the floor and outside an operator’s
normal ergonomic power zone. In either case, it is
much more economical to bring the worker to the
work rather than bringing the work to the worker.
In this project, we have modeled an aerial scissor
lift by using ANSYS software which is one of the
software used for modeling components in most
of the design based industries. While the modeling
of the components the material selection is
carried out simultaneously based on the design
considerations related to loads, etc. Later the
stress and strain concentration, deformation on
the aerial scissor lift have been found by applying
certain load on the lift’s platform, using the Finite
Element Analysis (FEA) by using ANSYS software
that provides best output within few seconds.
Finally the stress and strain concentration,
deformation result [11].
10. M. Kiran Kumar1, J. Chandrasheker2, Mahipal
Manda3, D.Vijay Kumar4. This paper is mainly
focused on force acting on the hydraulic scissor
lift when it is extended and contracted. Generally,
a hydraulic scissor lift is used for lifting and
holding heavy weight components. Material
selection plays a key role in designing a machine
and also influence on several factor such as
durability, reliability, strength, resistance which
finally leads to increase the life of scissor lift. The
design is performed by considering hydraulic
scissor lift as a portable, compact and much
suitable for medium type of load application.
Drafting & drawing of hydraulic system scissor lift
is done using solid works with suitable modeling
and imported to Ansys work bench for meshing
and analysis. Hence, the analysis of the scissor lift
includes Total deformation load, Equivalent
stress, was done in Ansys and all responsible
parameters were analyzed in order to check the
compatibility of the design value. The
computational values of two different materials
such as aluminum and mild steel are compared
for best results [12].
3. METHODOLOGY
Based on our types of ladders we observe following
methods can be proved useful in life.
1. Fixed Ladder :-
A fixed ladder is a vertical ladder mounted
permanently to a structure. These ladders are
primarily used to access roofs or other structures
for industrial purposes. Two side members joined
by several rungs; affixed to structure with no
moving parts. In addition, fixed ladders must meet
the following requirements:
o Fixed ladders must be able to support at
least two loads of 250 pounds (114 kg)
each, concentrated between any two
consecutive attachments. Fixed ladders
also must support added anticipated
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1197
loads caused by ice buildup, winds,
rigging and impact loads resulting from
using ladder safety devices.
o Individual rung/step ladders must extend
at least 42 inches (1.1 m) above an access
level or landing platform either by the
continuation of the rung spacing as
horizontal grab bars or by providing
vertical grab bars that must have the
same lateral spacing as the vertical legs of
the ladder rails.
o Each step or rung of a fixed ladder must
be able to support a load of at least 250
pounds (114 kg) applied in the middle of
the step or rung.
o Minimum clear distance between the
sides of individual rung/step ladders and
between the sides rails of other fixed
ladders must be 16 inches (41 cm).
o Rungs of individual rung/step ladders
must be shaped to prevent slipping off
the end of the rungs.
o Rungs and steps of fixed metal ladders
manufactured after March 15, 1991, must
be corrugated, knurled, dimpled, coated
with skid-resistant material or treated to
minimize slipping.
Advantages:
o The price is cheap
o Durable
o Simple shape
Disadvantages
o Not adjustable high
o Can’t be move
o Fix shape( can’t be form into other shape)
o Fix to the wall
2. Step Ladder :-
You can use either one or both sides for climbing,
depending on the step design. The twin-step ladder
describes the latter. However, you’ll find some models
where you can only use one side. These are called
simple front step ladders. The other side is for support
only. Spreaders join both and limit how far each can
move out from the center. They lock in place to keep it
from buckling when you’re stepping onto it. The
bottom portions are the feet or shoes. They typically
have some type of anti-skid material on the end of
them.
Advantages:
o Stable to use
o Foldable to store
o Durable
Disadvantages:
o Heavy to lift
o Not for high place maintenances job
o Difficult to carry
o Use a lot of space to store
o Only one side can be use(have rungs)
o Fix for one angle
3. Multi Purpose Folding Ladder:
The multipurpose ladder combines the features of
the step and extension models that increase its
versatility. It can be self-supporting or require
that you place it against something stable. It can
even stand in as scaffolding, depending on the
product. It’s a smart choice for a contractor or
the DIY handyman.
Advantages:
o Foldable
o Stable
o Adjustable high (can be form into many
shape for different high)
o Did not use a lot of space to store
Disadvantages:
o Heavy
o Difficult to bring
4. Telescopic Ladder:
Telestep is a company focused on producing
ladders and other tools that are able to quickly
and easily transform from compact and easy to
carry items to full size and usable tools.
Telescoping ladder, commonly used to refer to a
hybrid between a step ladder and an extension
ladder with 360-degree hinges; has three parts
and can be taken apart to form two step ladders.
Telesteps has three models of their famous
telescoping ladder. Titled after their maximum
height the three models are the 10.5 Foot Model,
the 12.5 Foot Model and the 14.5 Foot Model. The
obviously distinction between each is the
maximum height they are capable of reaching;
however weight should also be taken into
consideration as well as the size of the ladder
when it is in storage position. The higher the
maximum height of the ladder, the more it weighs
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1198
and the larger it will be in the storage position.
For some, of course, the biggest difference comes
when looking at the price tag. For every size you
move up, you have to be willing to pay a little
extra.
Advantages:
o Adjustable for high and medium high
place for maintenances job
o Foldable
o Stable to use because the base part is
more width
o Light weight (easy to lift to other place)
Disadvantages:
o Large and hard to keep or stored
o Difficult to lift to other place
5. Extension Ladder:
Extension ladders usually have two sections that
operate in brackets or guides that allow for the
ladder to be used at adjustable lengths. Extension
ladders are not self-supporting and require a
stable structure that can withstand the intended
load. Place ladders on a firm, level surface and
ensure the footing is secure.
o Erect extension ladders so that the upper
section rests on (e.g., in front of) the
bottom section. This placement means
the bottom section "faces" a wall or other
supporting surface (see figures below).
o Place the ladder feet so that the
horizontal distance between the feet and
the top support is 1/4 of the working
length of the ladder. The ladder will be
leaning at a 75 degree angle from the
ground. Raise and lower ladders from the
ground. Ensure that locking ladder hooks
are secure before climbing.
o For access to an elevated work surface,
erect ladders so that a minimum of 1 m (3
ft) extends above a landing platform. Tie
the top at support points.
o Use care when getting on and or off the
ladder at the top or bottom in order to
avoid tipping the ladder over sideways or
causing the ladder base to slide.
o Brace or tie off the ladder near the base. If
there is no structure to tie off to, use a
stake in the ground.
o Leave all tie-off devices in place until they
must be removed before taking the
ladder down.
o Maintain the minimum overlap of
sections as shown on a ladder label. Refer
to safety regulations.
o Set up barricades and warning signs
when using a ladder in a doorway or
passageway.
5. CONCLUSION
We studied Hydraulic Scissor ladder, Automatic Loft or
Attic Ladder, Rotary car parking system, Automatic liquid
filling ladder & Automatic vending machine ladder. The
main scope of the devices used for lifting purposes is to
make the table adjustable to a desired height and scope for
fire departments carry. Attic ladders on fire apparatus for
use to locate and extinguish fires in attic spaces. Scope for
automated car rotating system has been implemented to
reduce excess use of land place which is very scarce in
metro system. The automatic vending machine work is to
encourage small scale industries for the implementation of
automation in beverage preparation and its bottling plant
for Painting purpose, Electrical wireman, Plumber &
House working system.
REFERENCES
[1]Gaffar G Momin, Rohan Hatti, Karan Dalvi, Faisal Bargi,
Rohit Devare, Design Manufacturing & Analysis of
Hydraulic Scissor Lift, International Journal of Engineering
Research and General Science Volume 3, Issue 2, Part 2,
March-April, 2015,ISSN 2091-2730 733.
[2]Jaydeep, “Design And Kinematic Analysis Of Gear
Powered Scissor Lift” International Journal Of Emerging
Technology In Computer Science & Electronics (Ijetcse)
Issn: 0976-1353 Volume 12 Issue 3 –January 2015.
[3]Karan Dalvi Design, “Manufacturing & Analysis Of
Hydraulic Scissor Lift” International Journal Of
Engineering Research And General Science Volume 3,
Issue 2, Part 2, March-April, 2015 Issn 2091-2730.
[4]Todd J. Bacon“Belt-driven transportation system”
(2014).
[5]Dong et al describedAn Investigation on the Dynamic
Stability of Scissor Lift.
[6]]Richard E.Cullity, “scissor lift apparatus for work
platforms and the like”(1995).
[7] Marvelous Automatic Attic Stairs Jan 4, 2019
[8] “Design, Analysis and Development of Multiutility
home equipment using Scissor Lift Mechanism”, Divyesh
Prafulla Ubale, et al, International Journal of scientific
research and management (IJSRM), Volume-3, Issue-3,
Pages- 2405-2408, 2015.
[9] “Design and Analysis of Hydraulic Pallet System in
Chain Conveyor”, Setu Dabhi, et al, IJRET: International
International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1199
Journal of Research in Engineering and Technology eISSN:
2319-1163 ISSN: 2321-7308.
[10] “Finite Element analysis of Frame of Hydraulically
Operated Beam Lifting Machine” S. B. Naik, et al,
International Journal For Technological Research In
Engineering Volume 2, Issue 8, April-2015 ISSN (Online):
2347 – 4718
[11] Design and analysis of an aerial scissor Lift, M.
Abhinay, P.Sampath Rao,), SSRG International Journal of
Mechanical Engineering (SSRG-IJME) – volume1 issue 5
September2014 Mechanical Dept, VREC, Nizamabad-
503003
[12]“Design & Analysis of Hydraulic Scissor Lift” M. Kiran
Kumar1, J. Chandrasheker2, Mahipal Manda3 , D.Vijay
Kumar4, International Research Journal of Engineering
and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03
Issue: 06 June-2016 www.irjet.net p-ISSN: 2395-0072
[13] Design And Analysis Of An Aerial Scissor Lift, Jaydeep
M. Bhatt, Milan J. Pandya, Journal Of Information,
Knowledge And Research In Mechanical Engineering, Issn
0975 – 668x| Nov 12 To Oct 13 | Volume – 02, Issue – 02
[14] M. Ahmed, W.G. Wei, Study on Automated Car Parking
System Based on Microcontroller, IJERT, Vol. 3 Issue 1,
January-2014.
[15] “Automatic Multivariate Liquid Filling System &
Conveyor Control Using PLC & SCADA” , DherajPongalu,
Prof. S. R. Suralkar , International Journal of Emerging
Technology and Advanced Engineering (ISSN 2250-2459,
ISO 9001:2008 Certified Journal, Volume 4, Issue 12,
December 2014)
[16] H Ahuja, A Singh, S Tandon, S Srivastava, & S Pal.
Automatic Filling Management System for Industries.
International Journal of Emerging Technology and
Advanced Engineering. Vol. 4, Special Issue 1, February,
2014.
[17] Arturo Valencia Ochoa Jaime Antonio Uribe “Scissors
lift platform with electronic control”(1997).
[18] Enoch L. Newlin “Scissor lift mechanism employing
telescopable electro-mechanical based lift actuation
arrangement”(2000).
[19] Donald Watkins “Scissor lift mechanism” (2004).
[20] Mahmood Ronaghi, John Z. Wu, Christopher S. Pan,
James R. Harris, Daniel Welcome, Sharon S. Chiou, Brad
Boehler and Ren G. Dong“An initiative to model static
stability”(2009) .
[21] Ren G. Dong, Christopher S. Pan, Jared J. Hartsell,
Daniel E. Welcome, Tim Lutz, Anne Brumfield, James R.
Harris, John Z. Wu, BryanWimer, Victor Mucino,
Kenneth“An investigation on the dynamic stability of
scissor lift” (2012).
[22] M. J. Burkart, M. McCann and D. M. Paine, “Aerial
Work Platforms, in Elevated Work Platforms and
Scaffolding,” McGraw-Hill, New York, 2004.
[23] S. Mohan and W. C. Zech, “Characteristics of Worker
Accidents on NYSDOT Construction Projects,” Journal of
Safety Research, Vol. 36, No. 4, 2005, pp. 353-360.
doi:10.1016/j.jsr.2005.06.012.
[24] M. McCann, “Death in Construction Related to
Personnel Lifts, 1992-1999,” Journal of Safety Research,
Vol. 34, No. 5, 2003, pp. 507-514.
doi:10.1016/j.jsr.2003.07.001.
[25] C. S. Pan, A. Hoskin, M. McCann, D. Castillo, M. Lin and
K. Fern, “Aerial Lift Fall Injuries: A surveillance and
Evaluation Approach for Targeting Prevention Activities,”
Journal of Safety Research, Vol. 38, No. 6, 2007.
[26]NFPA 1931, Standard on Design of and Design
Verification Tests for Fire Department Ground Ladders,
contains the requirements for the design and
manufacturer’s testing of ground ladders
[27] NFPA 1932, Standard on Use, Maintenance, and
Service Testing of Fire Department Ground Ladders,
provides the requirements for both maintaining and
service testing ground ladders.
[28] NFPA 1901, Standard for Automotive Fire Apparatus,
set the minimum lengths and types of ladders to be carried
on all pumper or engine companies (one 10’ folding
ladder, one 14’ roof ladder, and one 24’ or larger extension
ladder).
[29] “Design, Manufacturing & Analysis of Hydraulic
Scissor Lift”, Gaffar G Momin, et al,International Journal Of
Engineering Research And General Science Volume 3,
Issue 2, Part 2, March-April, 2015,ISSN 2091-2730.
[30] Scissor Lift Tech Handbook, Omni metacraft
[31] Lift and Escalators: Basic Principles and Design, Dr.
Sam C M Hui Department of Mechanical Engineering The
University of Hong Kong.
[32] A Study In Lift Design9,000 Pound Capacity Four‐
Post Series Models: Hd‐ 9st Hd9, Ansi/Ali Alctv‐ 2006
Certified Product .

More Related Content

What's hot

DESIGN AND ANALYSIS OF GANTRY AUTOMATION SYSTEM FOR WHEEL HUB MACHINING IN VMC
DESIGN AND ANALYSIS OF GANTRY AUTOMATION SYSTEM FOR WHEEL HUB MACHINING IN VMCDESIGN AND ANALYSIS OF GANTRY AUTOMATION SYSTEM FOR WHEEL HUB MACHINING IN VMC
DESIGN AND ANALYSIS OF GANTRY AUTOMATION SYSTEM FOR WHEEL HUB MACHINING IN VMC
AM Publications
 
pro matter
pro matterpro matter
pro matter
Ebin C D
 
Optimization study on trailer arm chassis by finite element method
Optimization study on trailer arm chassis by finite element methodOptimization study on trailer arm chassis by finite element method
Optimization study on trailer arm chassis by finite element method
eSAT Journals
 
Design and Model of Bucket Elevator
Design and Model of Bucket ElevatorDesign and Model of Bucket Elevator
Design and Model of Bucket Elevator
Utkarsh Amaravat
 

What's hot (19)

Assignment parts feeder
Assignment parts feederAssignment parts feeder
Assignment parts feeder
 
IRJET- Design and Analysis of Chassis, Engine and Steering System of an ATV –...
IRJET- Design and Analysis of Chassis, Engine and Steering System of an ATV –...IRJET- Design and Analysis of Chassis, Engine and Steering System of an ATV –...
IRJET- Design and Analysis of Chassis, Engine and Steering System of an ATV –...
 
DESIGN AND ANALYSIS OF GANTRY AUTOMATION SYSTEM FOR WHEEL HUB MACHINING IN VMC
DESIGN AND ANALYSIS OF GANTRY AUTOMATION SYSTEM FOR WHEEL HUB MACHINING IN VMCDESIGN AND ANALYSIS OF GANTRY AUTOMATION SYSTEM FOR WHEEL HUB MACHINING IN VMC
DESIGN AND ANALYSIS OF GANTRY AUTOMATION SYSTEM FOR WHEEL HUB MACHINING IN VMC
 
Various Uses of Hydraulic Lifts
Various Uses of Hydraulic LiftsVarious Uses of Hydraulic Lifts
Various Uses of Hydraulic Lifts
 
Optimization of power consumption of belt conveyer system by replacing adjust...
Optimization of power consumption of belt conveyer system by replacing adjust...Optimization of power consumption of belt conveyer system by replacing adjust...
Optimization of power consumption of belt conveyer system by replacing adjust...
 
pro matter
pro matterpro matter
pro matter
 
Nexus Assembly Automation
Nexus Assembly AutomationNexus Assembly Automation
Nexus Assembly Automation
 
Optimization study on trailer arm chassis by finite element method
Optimization study on trailer arm chassis by finite element methodOptimization study on trailer arm chassis by finite element method
Optimization study on trailer arm chassis by finite element method
 
Design and Model of Bucket Elevator
Design and Model of Bucket ElevatorDesign and Model of Bucket Elevator
Design and Model of Bucket Elevator
 
Transfer devices and feeders
Transfer devices and feedersTransfer devices and feeders
Transfer devices and feeders
 
IRJET- Study on Effect of the Center of Gravity on Vehicular Acceleration
IRJET- Study on Effect of the Center of Gravity on Vehicular AccelerationIRJET- Study on Effect of the Center of Gravity on Vehicular Acceleration
IRJET- Study on Effect of the Center of Gravity on Vehicular Acceleration
 
Feeder equipment
Feeder equipmentFeeder equipment
Feeder equipment
 
HEC Project Report
HEC Project ReportHEC Project Report
HEC Project Report
 
IRJET- CAM Operated Punching Machine
IRJET-  	  CAM Operated Punching MachineIRJET-  	  CAM Operated Punching Machine
IRJET- CAM Operated Punching Machine
 
Study of Fabrication of Multipurpose Tooling Machine
Study of Fabrication of Multipurpose Tooling MachineStudy of Fabrication of Multipurpose Tooling Machine
Study of Fabrication of Multipurpose Tooling Machine
 
Design procedure of an electrohydraulic drive
Design procedure of an electrohydraulic driveDesign procedure of an electrohydraulic drive
Design procedure of an electrohydraulic drive
 
blitzkrieg
blitzkriegblitzkrieg
blitzkrieg
 
Ergonomic improvement in operator seat and controls of small tractor
Ergonomic improvement in operator seat and controls of small tractorErgonomic improvement in operator seat and controls of small tractor
Ergonomic improvement in operator seat and controls of small tractor
 
Fabrication of automatic hydraulic bending and bend removing machine
Fabrication of automatic hydraulic bending and bend removing machineFabrication of automatic hydraulic bending and bend removing machine
Fabrication of automatic hydraulic bending and bend removing machine
 

Similar to IRJET- Smart Ladder: A Survey

Similar to IRJET- Smart Ladder: A Survey (20)

IRJET- Operating Mechanism and Design of Hydraulic Scissor Lift
IRJET-  	  Operating Mechanism and Design of Hydraulic Scissor LiftIRJET-  	  Operating Mechanism and Design of Hydraulic Scissor Lift
IRJET- Operating Mechanism and Design of Hydraulic Scissor Lift
 
Application of support foot assembly for lifting heavy equipment’s
Application of support foot assembly for lifting heavy equipment’sApplication of support foot assembly for lifting heavy equipment’s
Application of support foot assembly for lifting heavy equipment’s
 
DESIGN & MANUFACTURING OF WHEELCHAIR LIFTER
DESIGN & MANUFACTURING OF WHEELCHAIR LIFTERDESIGN & MANUFACTURING OF WHEELCHAIR LIFTER
DESIGN & MANUFACTURING OF WHEELCHAIR LIFTER
 
IRJET- Final Modeling and Prototype & Analysis of Hydraulic Scissor Lift
IRJET- Final Modeling and Prototype & Analysis of Hydraulic Scissor LiftIRJET- Final Modeling and Prototype & Analysis of Hydraulic Scissor Lift
IRJET- Final Modeling and Prototype & Analysis of Hydraulic Scissor Lift
 
IRJET- Design and Manufacturing of Ladder Roof Lift for Material Lifting
IRJET-  	  Design and Manufacturing of Ladder Roof Lift for Material LiftingIRJET-  	  Design and Manufacturing of Ladder Roof Lift for Material Lifting
IRJET- Design and Manufacturing of Ladder Roof Lift for Material Lifting
 
IRJET- Design and Fabrication of Mechanized Stair
IRJET-  	  Design and Fabrication of Mechanized StairIRJET-  	  Design and Fabrication of Mechanized Stair
IRJET- Design and Fabrication of Mechanized Stair
 
IRJET- Design and Development Pedal Operated Multi-Crop Thresher with Vibrati...
IRJET- Design and Development Pedal Operated Multi-Crop Thresher with Vibrati...IRJET- Design and Development Pedal Operated Multi-Crop Thresher with Vibrati...
IRJET- Design and Development Pedal Operated Multi-Crop Thresher with Vibrati...
 
IRJET- A Review on Design and Fabrication of Loading and Unloading System for...
IRJET- A Review on Design and Fabrication of Loading and Unloading System for...IRJET- A Review on Design and Fabrication of Loading and Unloading System for...
IRJET- A Review on Design and Fabrication of Loading and Unloading System for...
 
IRJET- 360 Degree Rotated Gearbox Trolley
IRJET-  	  360 Degree Rotated Gearbox TrolleyIRJET-  	  360 Degree Rotated Gearbox Trolley
IRJET- 360 Degree Rotated Gearbox Trolley
 
DESIGN & MANUFACTURING OF SHUNTING TROLLEY
DESIGN & MANUFACTURING OF SHUNTING TROLLEYDESIGN & MANUFACTURING OF SHUNTING TROLLEY
DESIGN & MANUFACTURING OF SHUNTING TROLLEY
 
IRJET- Conveyor System and Storage Hopper: Introduction, Types, Design Consid...
IRJET- Conveyor System and Storage Hopper: Introduction, Types, Design Consid...IRJET- Conveyor System and Storage Hopper: Introduction, Types, Design Consid...
IRJET- Conveyor System and Storage Hopper: Introduction, Types, Design Consid...
 
Design and Development of Pneumatic Scissor Lift
Design and Development of Pneumatic Scissor LiftDesign and Development of Pneumatic Scissor Lift
Design and Development of Pneumatic Scissor Lift
 
IRJET- Six Axis Pneumatic Materials Handling Robotic Arm
IRJET-  	  Six Axis Pneumatic Materials Handling Robotic ArmIRJET-  	  Six Axis Pneumatic Materials Handling Robotic Arm
IRJET- Six Axis Pneumatic Materials Handling Robotic Arm
 
IRJET- Design and Fabrication of Rack and Pinion Jack
IRJET- Design and Fabrication of Rack and Pinion JackIRJET- Design and Fabrication of Rack and Pinion Jack
IRJET- Design and Fabrication of Rack and Pinion Jack
 
Vertical material handling system
Vertical material handling systemVertical material handling system
Vertical material handling system
 
Vertical material handling system
Vertical material handling systemVertical material handling system
Vertical material handling system
 
Motorized Sccissor Lift
Motorized Sccissor Lift Motorized Sccissor Lift
Motorized Sccissor Lift
 
Design and Fabrication of Automated Motorized Mechanical Jack
Design and Fabrication of Automated Motorized Mechanical JackDesign and Fabrication of Automated Motorized Mechanical Jack
Design and Fabrication of Automated Motorized Mechanical Jack
 
Fabrication of Stair Climber Material Handling System for Small Scale Industry
Fabrication of Stair Climber Material Handling System for Small Scale IndustryFabrication of Stair Climber Material Handling System for Small Scale Industry
Fabrication of Stair Climber Material Handling System for Small Scale Industry
 
Regenerative Elevator With Backup Plan
Regenerative Elevator With Backup PlanRegenerative Elevator With Backup Plan
Regenerative Elevator With Backup Plan
 

More from IRJET Journal

More from IRJET Journal (20)

TUNNELING IN HIMALAYAS WITH NATM METHOD: A SPECIAL REFERENCES TO SUNGAL TUNNE...
TUNNELING IN HIMALAYAS WITH NATM METHOD: A SPECIAL REFERENCES TO SUNGAL TUNNE...TUNNELING IN HIMALAYAS WITH NATM METHOD: A SPECIAL REFERENCES TO SUNGAL TUNNE...
TUNNELING IN HIMALAYAS WITH NATM METHOD: A SPECIAL REFERENCES TO SUNGAL TUNNE...
 
STUDY THE EFFECT OF RESPONSE REDUCTION FACTOR ON RC FRAMED STRUCTURE
STUDY THE EFFECT OF RESPONSE REDUCTION FACTOR ON RC FRAMED STRUCTURESTUDY THE EFFECT OF RESPONSE REDUCTION FACTOR ON RC FRAMED STRUCTURE
STUDY THE EFFECT OF RESPONSE REDUCTION FACTOR ON RC FRAMED STRUCTURE
 
A COMPARATIVE ANALYSIS OF RCC ELEMENT OF SLAB WITH STARK STEEL (HYSD STEEL) A...
A COMPARATIVE ANALYSIS OF RCC ELEMENT OF SLAB WITH STARK STEEL (HYSD STEEL) A...A COMPARATIVE ANALYSIS OF RCC ELEMENT OF SLAB WITH STARK STEEL (HYSD STEEL) A...
A COMPARATIVE ANALYSIS OF RCC ELEMENT OF SLAB WITH STARK STEEL (HYSD STEEL) A...
 
Effect of Camber and Angles of Attack on Airfoil Characteristics
Effect of Camber and Angles of Attack on Airfoil CharacteristicsEffect of Camber and Angles of Attack on Airfoil Characteristics
Effect of Camber and Angles of Attack on Airfoil Characteristics
 
A Review on the Progress and Challenges of Aluminum-Based Metal Matrix Compos...
A Review on the Progress and Challenges of Aluminum-Based Metal Matrix Compos...A Review on the Progress and Challenges of Aluminum-Based Metal Matrix Compos...
A Review on the Progress and Challenges of Aluminum-Based Metal Matrix Compos...
 
Dynamic Urban Transit Optimization: A Graph Neural Network Approach for Real-...
Dynamic Urban Transit Optimization: A Graph Neural Network Approach for Real-...Dynamic Urban Transit Optimization: A Graph Neural Network Approach for Real-...
Dynamic Urban Transit Optimization: A Graph Neural Network Approach for Real-...
 
Structural Analysis and Design of Multi-Storey Symmetric and Asymmetric Shape...
Structural Analysis and Design of Multi-Storey Symmetric and Asymmetric Shape...Structural Analysis and Design of Multi-Storey Symmetric and Asymmetric Shape...
Structural Analysis and Design of Multi-Storey Symmetric and Asymmetric Shape...
 
A Review of “Seismic Response of RC Structures Having Plan and Vertical Irreg...
A Review of “Seismic Response of RC Structures Having Plan and Vertical Irreg...A Review of “Seismic Response of RC Structures Having Plan and Vertical Irreg...
A Review of “Seismic Response of RC Structures Having Plan and Vertical Irreg...
 
A REVIEW ON MACHINE LEARNING IN ADAS
A REVIEW ON MACHINE LEARNING IN ADASA REVIEW ON MACHINE LEARNING IN ADAS
A REVIEW ON MACHINE LEARNING IN ADAS
 
Long Term Trend Analysis of Precipitation and Temperature for Asosa district,...
Long Term Trend Analysis of Precipitation and Temperature for Asosa district,...Long Term Trend Analysis of Precipitation and Temperature for Asosa district,...
Long Term Trend Analysis of Precipitation and Temperature for Asosa district,...
 
P.E.B. Framed Structure Design and Analysis Using STAAD Pro
P.E.B. Framed Structure Design and Analysis Using STAAD ProP.E.B. Framed Structure Design and Analysis Using STAAD Pro
P.E.B. Framed Structure Design and Analysis Using STAAD Pro
 
A Review on Innovative Fiber Integration for Enhanced Reinforcement of Concre...
A Review on Innovative Fiber Integration for Enhanced Reinforcement of Concre...A Review on Innovative Fiber Integration for Enhanced Reinforcement of Concre...
A Review on Innovative Fiber Integration for Enhanced Reinforcement of Concre...
 
Survey Paper on Cloud-Based Secured Healthcare System
Survey Paper on Cloud-Based Secured Healthcare SystemSurvey Paper on Cloud-Based Secured Healthcare System
Survey Paper on Cloud-Based Secured Healthcare System
 
Review on studies and research on widening of existing concrete bridges
Review on studies and research on widening of existing concrete bridgesReview on studies and research on widening of existing concrete bridges
Review on studies and research on widening of existing concrete bridges
 
React based fullstack edtech web application
React based fullstack edtech web applicationReact based fullstack edtech web application
React based fullstack edtech web application
 
A Comprehensive Review of Integrating IoT and Blockchain Technologies in the ...
A Comprehensive Review of Integrating IoT and Blockchain Technologies in the ...A Comprehensive Review of Integrating IoT and Blockchain Technologies in the ...
A Comprehensive Review of Integrating IoT and Blockchain Technologies in the ...
 
A REVIEW ON THE PERFORMANCE OF COCONUT FIBRE REINFORCED CONCRETE.
A REVIEW ON THE PERFORMANCE OF COCONUT FIBRE REINFORCED CONCRETE.A REVIEW ON THE PERFORMANCE OF COCONUT FIBRE REINFORCED CONCRETE.
A REVIEW ON THE PERFORMANCE OF COCONUT FIBRE REINFORCED CONCRETE.
 
Optimizing Business Management Process Workflows: The Dynamic Influence of Mi...
Optimizing Business Management Process Workflows: The Dynamic Influence of Mi...Optimizing Business Management Process Workflows: The Dynamic Influence of Mi...
Optimizing Business Management Process Workflows: The Dynamic Influence of Mi...
 
Multistoried and Multi Bay Steel Building Frame by using Seismic Design
Multistoried and Multi Bay Steel Building Frame by using Seismic DesignMultistoried and Multi Bay Steel Building Frame by using Seismic Design
Multistoried and Multi Bay Steel Building Frame by using Seismic Design
 
Cost Optimization of Construction Using Plastic Waste as a Sustainable Constr...
Cost Optimization of Construction Using Plastic Waste as a Sustainable Constr...Cost Optimization of Construction Using Plastic Waste as a Sustainable Constr...
Cost Optimization of Construction Using Plastic Waste as a Sustainable Constr...
 

Recently uploaded

Hospital management system project report.pdf
Hospital management system project report.pdfHospital management system project report.pdf
Hospital management system project report.pdf
Kamal Acharya
 
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills KuwaitKuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
jaanualu31
 
scipt v1.pptxcxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...
scipt v1.pptxcxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...scipt v1.pptxcxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...
scipt v1.pptxcxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...
HenryBriggs2
 
1_Introduction + EAM Vocabulary + how to navigate in EAM.pdf
1_Introduction + EAM Vocabulary + how to navigate in EAM.pdf1_Introduction + EAM Vocabulary + how to navigate in EAM.pdf
1_Introduction + EAM Vocabulary + how to navigate in EAM.pdf
AldoGarca30
 
Standard vs Custom Battery Packs - Decoding the Power Play
Standard vs Custom Battery Packs - Decoding the Power PlayStandard vs Custom Battery Packs - Decoding the Power Play
Standard vs Custom Battery Packs - Decoding the Power Play
Epec Engineered Technologies
 

Recently uploaded (20)

Introduction to Data Visualization,Matplotlib.pdf
Introduction to Data Visualization,Matplotlib.pdfIntroduction to Data Visualization,Matplotlib.pdf
Introduction to Data Visualization,Matplotlib.pdf
 
School management system project Report.pdf
School management system project Report.pdfSchool management system project Report.pdf
School management system project Report.pdf
 
Design For Accessibility: Getting it right from the start
Design For Accessibility: Getting it right from the startDesign For Accessibility: Getting it right from the start
Design For Accessibility: Getting it right from the start
 
Hospital management system project report.pdf
Hospital management system project report.pdfHospital management system project report.pdf
Hospital management system project report.pdf
 
Online electricity billing project report..pdf
Online electricity billing project report..pdfOnline electricity billing project report..pdf
Online electricity billing project report..pdf
 
UNIT 4 PTRP final Convergence in probability.pptx
UNIT 4 PTRP final Convergence in probability.pptxUNIT 4 PTRP final Convergence in probability.pptx
UNIT 4 PTRP final Convergence in probability.pptx
 
8086 Microprocessor Architecture: 16-bit microprocessor
8086 Microprocessor Architecture: 16-bit microprocessor8086 Microprocessor Architecture: 16-bit microprocessor
8086 Microprocessor Architecture: 16-bit microprocessor
 
Basic Electronics for diploma students as per technical education Kerala Syll...
Basic Electronics for diploma students as per technical education Kerala Syll...Basic Electronics for diploma students as per technical education Kerala Syll...
Basic Electronics for diploma students as per technical education Kerala Syll...
 
Post office management system project ..pdf
Post office management system project ..pdfPost office management system project ..pdf
Post office management system project ..pdf
 
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills KuwaitKuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
Kuwait City MTP kit ((+919101817206)) Buy Abortion Pills Kuwait
 
fitting shop and tools used in fitting shop .ppt
fitting shop and tools used in fitting shop .pptfitting shop and tools used in fitting shop .ppt
fitting shop and tools used in fitting shop .ppt
 
Signal Processing and Linear System Analysis
Signal Processing and Linear System AnalysisSignal Processing and Linear System Analysis
Signal Processing and Linear System Analysis
 
Linux Systems Programming: Inter Process Communication (IPC) using Pipes
Linux Systems Programming: Inter Process Communication (IPC) using PipesLinux Systems Programming: Inter Process Communication (IPC) using Pipes
Linux Systems Programming: Inter Process Communication (IPC) using Pipes
 
scipt v1.pptxcxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...
scipt v1.pptxcxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...scipt v1.pptxcxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...
scipt v1.pptxcxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...
 
HAND TOOLS USED AT ELECTRONICS WORK PRESENTED BY KOUSTAV SARKAR
HAND TOOLS USED AT ELECTRONICS WORK PRESENTED BY KOUSTAV SARKARHAND TOOLS USED AT ELECTRONICS WORK PRESENTED BY KOUSTAV SARKAR
HAND TOOLS USED AT ELECTRONICS WORK PRESENTED BY KOUSTAV SARKAR
 
1_Introduction + EAM Vocabulary + how to navigate in EAM.pdf
1_Introduction + EAM Vocabulary + how to navigate in EAM.pdf1_Introduction + EAM Vocabulary + how to navigate in EAM.pdf
1_Introduction + EAM Vocabulary + how to navigate in EAM.pdf
 
NO1 Top No1 Amil Baba In Azad Kashmir, Kashmir Black Magic Specialist Expert ...
NO1 Top No1 Amil Baba In Azad Kashmir, Kashmir Black Magic Specialist Expert ...NO1 Top No1 Amil Baba In Azad Kashmir, Kashmir Black Magic Specialist Expert ...
NO1 Top No1 Amil Baba In Azad Kashmir, Kashmir Black Magic Specialist Expert ...
 
Introduction to Geographic Information Systems
Introduction to Geographic Information SystemsIntroduction to Geographic Information Systems
Introduction to Geographic Information Systems
 
Standard vs Custom Battery Packs - Decoding the Power Play
Standard vs Custom Battery Packs - Decoding the Power PlayStandard vs Custom Battery Packs - Decoding the Power Play
Standard vs Custom Battery Packs - Decoding the Power Play
 
Theory of Time 2024 (Universal Theory for Everything)
Theory of Time 2024 (Universal Theory for Everything)Theory of Time 2024 (Universal Theory for Everything)
Theory of Time 2024 (Universal Theory for Everything)
 

IRJET- Smart Ladder: A Survey

  • 1. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1193 Smart Ladder: A Survey Tareek Pattewar1, Megha Surywanshi2, Ankita Chaure3, Harshal Chaudhari4 , Priyanka Patil5 Anushka Bedse6 1Assistant Professor, Dept. of Information Technology, R. C. Patel Institute of Technology, Maharashtra, India 2, 3,4,5,6Student, Dept. of Information Technology, R. C. Patel Institute of Technology, Maharashtra, India ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract -Now a days ladders are important and essential tools that are used widely in a variety of industries. A ladder is a piece of equipment consisting of a series of bars or steps between two upright lengths of wood, metal or rope used for climbing up or down something. They help us move up and down and work at different heights. Portable ladders, in particular, are useful tools because they can be readily moved or carried. They are simply built and come in many sizes, shapes and styles. Key Words: Hydraulic cylinder, Pulley, Microcontroller, Belt, Lock, Battery, Motor. 1. INTRODUCTION 1.1 Different type of mechanism: 1. Hydraulic Scissor ladder: “The machine which is achieved desired height by the using of linkages, folding support in the scissor form is known as scissor mechanism.” A scissor ladder mechanism is a device used to extend or react a platform by hydraulic means. The extension and or displacement motion is achieved by application of force by hydraulic cylinder to one or more support. This forces results is an elongation of the cross pattern. Retraction through hydraulic cylinder is also achieved when lowering of platform is desired. A scissor life table has many useful purposes. The applications of a scissor lift table include a variety of things, but the platform is ultimately designed to help lift and raise heavier objects. The industrial lift is most often seen in behind the scenes of retail establishments and warehouses, although manufacturing engineers are always redesigning the lift for various uses like lifting heavy loads. A hydraulic scissor lift is a mechanical device used for various applications for lifting of the loads to a height or level [1]. A lift table is defined as a scissor lift used to stack, raise or lower, convey and/or transfer material between two or more elevations Fig1. Hydraulic Scissor ladder [1] 2. Automatic Loft / Attic Ladder: An attic ladder (US) or loft ladder (UK) is a retractable ladder that is installed into the floor of an attic and ceiling of the floor below the attic. They are used as an inexpensive and compact alternative to having a stairway that ascends to the attic of a building. They are useful in areas with space constraints that would hinder the installation of a standard staircase. Attic ladders typically consist of a ladder with wider steps and a steep slope.[1] A drawstring will hang down to allow the ladder to be manually extended. Attic ladders are usually made of wood, metal, aluminum. The fire departments carry attic ladders on fire apparatus for use to locate and extinguish fires in attic spaces. They are in a single ladder that is often used by firefighters for interior attic access and have hinged rungs, which allow them to be folded inward so that one beam rests on the other, with the rungs hidden away in the middle[7]. This compatibility allows it to be carried in attic scuttle holes, narrow passageways, and small rooms or closets.
  • 2. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1194 Fig2. Automatic Loft / Attic Ladder [7] 3. Rotary car parking system: It is simple to operate with the driver parking and leaving the vehicle in the system at the ground level. Once the driver leaves the incorporated safety zone the vehicle is automatically parked by the system rotating to lift the parked car away from the bottom central position. This leaves an empty parking space available at the ground level for the next car to be parked on. The parked car is easily retrieved by pushing the button for the relevant position number the car is parked on. This causes the required car to rotate down to ground level ready for the driver to enter the safety zone and reverse the car out of the system [14]. Fig3. Rotary car parking system 4. Automatic Liquid filing mechanism horizontal ladder: Nowadays with many industrial applications, a conveyor system is used to move object from one location to another effective way to reduce losing time and effort and it is very useful in packaging process. A conveyor system has several forms but in this paper, a Flat belt type is used to move the bottles as shown in Fig. (4). Conveyors are especially useful in applications which including the transportation of heavy or large materials. A Flat belt conveyer has a dimensions of (120*70*30) cm the belt is made from elastic material [15]. Six pulleys a distributed along the belt, the first one rotates with the rotation of motor shaft and it usually called drive pulley and the other five pulley called idler pulley. Fig4.Automatic liquid filling ladder [15] 5. Ladder Automatic Vending Machine: During this industrialization vending machines play an important role for fulfilling the process immediate needs of the society. In a challenge to competitive industrial world, a system must be flexible, efficient and cost effective; so automation in machines is very much essential. When to design a program under which whenever a user’s insert 5 rupees coin it will dispense tea and for 10 rupees coin it will dispense coffee and also count the number of coffee and tea served for the time. It requires a PLC Brand and model of SIEMENS S7 SERIES 312, IFM Communication and SIMATIC Manager [16].
  • 3. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1195 Fig5. Automatic vending machine ladder [16] 2. LITREATURE SURVEY 1. Jaydeep et.al Design And Kinematic Analysis Of Gear Powered Scissor Lift Conventionally a scissor lift or jack is used for lifting a vehicle to change a tire, to gain access to go to the underside of the vehicle, to lift the body to appreciable height, and many other applications Also such lifts can be used for various purposes like maintenance and many material handling operations. It can be of mechanical, pneumatic or hydraulic type. The design described in the paper is developed keeping in mind that the lift can be operated by mechanical means so that the overall cost of the scissor lift is reduced. Also such design can make the lift more compact and much suitable for medium scale work. Finally the analysis is also carried out in order to check the compatibility of the design values [2]. 2. Gaffar G Momin, Rohan Hatti, Karan Dalvi, Faisal Bargi, Rohit Devare,et.al,have proposed Design Manufacturing Analysis of Hydraulic Scissor Lift, In their paper they have discussed about is mainly focused on force acting on the hydraulic scissor lift when it is extended and contracted. Generally, a hydraulic scissor lift is used for lifting and holding heavy weight components. Material selection plays a key role in designing a machine and also influence on several factor such as durability,reliability, strength. [1]. 3. Karan Dalvi Design, et.al Manufacturing Analysis Of Hydraulic Scissor Lift is a simple mechanical device used to raise element or object from ground level to a certain height to perform a specific work with maximum load and minimum efforts. This project describes the design as well as analysis of a mechanical scissor lift which works on the principle of screw jack. The design will be developed keeping in mind that the lift can be operated by mechanical means so that the overall cost of the scissor lift is reduced [3]. 4. Todd J. Bacon designed a belt-driven transportation system including a first set of pulleys rotatable attached to a second member and a second set of pulleys rotatable attached to a second member. The first and second members have relative movement to each other .The system further includes a unitary belt that is guided through a path defined by the first and second sets of pulleys. A plurality of range members maintain a proper positioning of the belt on the pulleys. [4]. 5. Dong et al described that the tip-over of scissor lifts in operation has frequently resulted in the death and/or severe injuries of workers. Two series of experiments were performed under possible tip-over scenarios: curb impact and pothole depression. The results suggest that the lift should not be elevated on largely deformable and/or uneven surfaces such as bridged wood board or a soft soil base. The worker on the lift platform should avoid any large continuous periodic movement or forceful action in the horizontal plane, especially when the lift is fully elevated. Besides the tilt angle of the lift, the tilt speed should be monitored to help prevent the tipover. [5]. 6. Richard et al developed a scissor lift apparatus that has three scissor units for supplying heavy 1oads. A central Scissor unit has its arms located inwardly of the immediately lower and upper scissor units, and folds into the upper and lower scissor units for storage within a chamber in a mobile chassis The scissor arms of the upper and lower scissor units includes rectangular box beams with a great vertical than horizontal dimension. Hydraulic cylinders are located within and coupled to the opposite two arms of the center scissor unit to expand and collapse the same. [6]. 7. Divyesh Prafulla Ubale, et al. The conventional method of using rope, ladder lift getting person to a height encounter a lot of limitation (time and energy consumption, comfortability, amount of load that can be carried etc.) also there may be a risk of falling down in case of ladders hence hydraulic scissors lift is designed to overcome all these difficulties. The main aim of this paper is design and analysis and to construct a multiutility home equipment for senior citizens so that they can carry their daily activities efficiently. Also the equipment should be compact and cost effective. Lifting height achieved by scissor mechanism is of
  • 4. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1196 1 m from bottom level. Buckling and bending failure analysis of scissor is also done in this paper. With ceaseless development of science and technology, more and more new technologies are applied to lifting appliance design. This project aims at making equipment multifunctional, easy to use/operate, cost effective and portable so that it will be used conveniently at home and may be used in hospitals, hotels and other common places. Senior citizens face many problems to carry out their day to day activities, as this equipment is designed in such a way that (e.g. it is remote operated with battery) they can easily move in house and perform day to day activities. All safety considerations are taken into account while designing equipment. Scissor lifting mechanism is designed to lift person to desired height. A scissor lift mechanism is a device used to extend or retract a platform by hydraulic means. The Extension or displacement motion is achieved by the application of force by hydraulic cylinder to one or more supports. This force results in an elongation of the cross pattern. Retraction through hydraulic cylinder is also achieved when lowering of platform is desired [8]. 8. S. B. Naik, et al A special type of beam lifting device is designed for textile industries. The machine is hydraulically operated and is having two frames one horizontal and another vertical. Horizontal frame is mounted with two telescopic cylinders used for beam lifting to required height. The mobility for the structure is provided by using castor wheels. Finite element analysis of the frames is done by ANSYS software considering the need of the textile industries, a special purpose machine has been designed to lift the beams in textile industries. The finite element analysis of the frame of this machine is done to get the idea of the stresses & deformation of the structure in order to modify the same if needed [10]. 9. M. Abhinay, P.Sampath Rao Aerial scissor lifts are generally used for temporary, flexible access purposes such as maintenance and construction work or by fire-fighters for emergency access, etc which distinguishes them from permanent access equipment such as elevators. They are designed to lift limited weights usually less than a ton, although some have a higher safe working load (SWL). The increasing demand of Aerial Scissor Lifts in companies in order to improve their manufacturing flexibility and output by providing variable height access to their work. This is especially true when the work being accessed is raised off the floor and outside an operator’s normal ergonomic power zone. In either case, it is much more economical to bring the worker to the work rather than bringing the work to the worker. In this project, we have modeled an aerial scissor lift by using ANSYS software which is one of the software used for modeling components in most of the design based industries. While the modeling of the components the material selection is carried out simultaneously based on the design considerations related to loads, etc. Later the stress and strain concentration, deformation on the aerial scissor lift have been found by applying certain load on the lift’s platform, using the Finite Element Analysis (FEA) by using ANSYS software that provides best output within few seconds. Finally the stress and strain concentration, deformation result [11]. 10. M. Kiran Kumar1, J. Chandrasheker2, Mahipal Manda3, D.Vijay Kumar4. This paper is mainly focused on force acting on the hydraulic scissor lift when it is extended and contracted. Generally, a hydraulic scissor lift is used for lifting and holding heavy weight components. Material selection plays a key role in designing a machine and also influence on several factor such as durability, reliability, strength, resistance which finally leads to increase the life of scissor lift. The design is performed by considering hydraulic scissor lift as a portable, compact and much suitable for medium type of load application. Drafting & drawing of hydraulic system scissor lift is done using solid works with suitable modeling and imported to Ansys work bench for meshing and analysis. Hence, the analysis of the scissor lift includes Total deformation load, Equivalent stress, was done in Ansys and all responsible parameters were analyzed in order to check the compatibility of the design value. The computational values of two different materials such as aluminum and mild steel are compared for best results [12]. 3. METHODOLOGY Based on our types of ladders we observe following methods can be proved useful in life. 1. Fixed Ladder :- A fixed ladder is a vertical ladder mounted permanently to a structure. These ladders are primarily used to access roofs or other structures for industrial purposes. Two side members joined by several rungs; affixed to structure with no moving parts. In addition, fixed ladders must meet the following requirements: o Fixed ladders must be able to support at least two loads of 250 pounds (114 kg) each, concentrated between any two consecutive attachments. Fixed ladders also must support added anticipated
  • 5. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1197 loads caused by ice buildup, winds, rigging and impact loads resulting from using ladder safety devices. o Individual rung/step ladders must extend at least 42 inches (1.1 m) above an access level or landing platform either by the continuation of the rung spacing as horizontal grab bars or by providing vertical grab bars that must have the same lateral spacing as the vertical legs of the ladder rails. o Each step or rung of a fixed ladder must be able to support a load of at least 250 pounds (114 kg) applied in the middle of the step or rung. o Minimum clear distance between the sides of individual rung/step ladders and between the sides rails of other fixed ladders must be 16 inches (41 cm). o Rungs of individual rung/step ladders must be shaped to prevent slipping off the end of the rungs. o Rungs and steps of fixed metal ladders manufactured after March 15, 1991, must be corrugated, knurled, dimpled, coated with skid-resistant material or treated to minimize slipping. Advantages: o The price is cheap o Durable o Simple shape Disadvantages o Not adjustable high o Can’t be move o Fix shape( can’t be form into other shape) o Fix to the wall 2. Step Ladder :- You can use either one or both sides for climbing, depending on the step design. The twin-step ladder describes the latter. However, you’ll find some models where you can only use one side. These are called simple front step ladders. The other side is for support only. Spreaders join both and limit how far each can move out from the center. They lock in place to keep it from buckling when you’re stepping onto it. The bottom portions are the feet or shoes. They typically have some type of anti-skid material on the end of them. Advantages: o Stable to use o Foldable to store o Durable Disadvantages: o Heavy to lift o Not for high place maintenances job o Difficult to carry o Use a lot of space to store o Only one side can be use(have rungs) o Fix for one angle 3. Multi Purpose Folding Ladder: The multipurpose ladder combines the features of the step and extension models that increase its versatility. It can be self-supporting or require that you place it against something stable. It can even stand in as scaffolding, depending on the product. It’s a smart choice for a contractor or the DIY handyman. Advantages: o Foldable o Stable o Adjustable high (can be form into many shape for different high) o Did not use a lot of space to store Disadvantages: o Heavy o Difficult to bring 4. Telescopic Ladder: Telestep is a company focused on producing ladders and other tools that are able to quickly and easily transform from compact and easy to carry items to full size and usable tools. Telescoping ladder, commonly used to refer to a hybrid between a step ladder and an extension ladder with 360-degree hinges; has three parts and can be taken apart to form two step ladders. Telesteps has three models of their famous telescoping ladder. Titled after their maximum height the three models are the 10.5 Foot Model, the 12.5 Foot Model and the 14.5 Foot Model. The obviously distinction between each is the maximum height they are capable of reaching; however weight should also be taken into consideration as well as the size of the ladder when it is in storage position. The higher the maximum height of the ladder, the more it weighs
  • 6. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1198 and the larger it will be in the storage position. For some, of course, the biggest difference comes when looking at the price tag. For every size you move up, you have to be willing to pay a little extra. Advantages: o Adjustable for high and medium high place for maintenances job o Foldable o Stable to use because the base part is more width o Light weight (easy to lift to other place) Disadvantages: o Large and hard to keep or stored o Difficult to lift to other place 5. Extension Ladder: Extension ladders usually have two sections that operate in brackets or guides that allow for the ladder to be used at adjustable lengths. Extension ladders are not self-supporting and require a stable structure that can withstand the intended load. Place ladders on a firm, level surface and ensure the footing is secure. o Erect extension ladders so that the upper section rests on (e.g., in front of) the bottom section. This placement means the bottom section "faces" a wall or other supporting surface (see figures below). o Place the ladder feet so that the horizontal distance between the feet and the top support is 1/4 of the working length of the ladder. The ladder will be leaning at a 75 degree angle from the ground. Raise and lower ladders from the ground. Ensure that locking ladder hooks are secure before climbing. o For access to an elevated work surface, erect ladders so that a minimum of 1 m (3 ft) extends above a landing platform. Tie the top at support points. o Use care when getting on and or off the ladder at the top or bottom in order to avoid tipping the ladder over sideways or causing the ladder base to slide. o Brace or tie off the ladder near the base. If there is no structure to tie off to, use a stake in the ground. o Leave all tie-off devices in place until they must be removed before taking the ladder down. o Maintain the minimum overlap of sections as shown on a ladder label. Refer to safety regulations. o Set up barricades and warning signs when using a ladder in a doorway or passageway. 5. CONCLUSION We studied Hydraulic Scissor ladder, Automatic Loft or Attic Ladder, Rotary car parking system, Automatic liquid filling ladder & Automatic vending machine ladder. The main scope of the devices used for lifting purposes is to make the table adjustable to a desired height and scope for fire departments carry. Attic ladders on fire apparatus for use to locate and extinguish fires in attic spaces. Scope for automated car rotating system has been implemented to reduce excess use of land place which is very scarce in metro system. The automatic vending machine work is to encourage small scale industries for the implementation of automation in beverage preparation and its bottling plant for Painting purpose, Electrical wireman, Plumber & House working system. REFERENCES [1]Gaffar G Momin, Rohan Hatti, Karan Dalvi, Faisal Bargi, Rohit Devare, Design Manufacturing & Analysis of Hydraulic Scissor Lift, International Journal of Engineering Research and General Science Volume 3, Issue 2, Part 2, March-April, 2015,ISSN 2091-2730 733. [2]Jaydeep, “Design And Kinematic Analysis Of Gear Powered Scissor Lift” International Journal Of Emerging Technology In Computer Science & Electronics (Ijetcse) Issn: 0976-1353 Volume 12 Issue 3 –January 2015. [3]Karan Dalvi Design, “Manufacturing & Analysis Of Hydraulic Scissor Lift” International Journal Of Engineering Research And General Science Volume 3, Issue 2, Part 2, March-April, 2015 Issn 2091-2730. [4]Todd J. Bacon“Belt-driven transportation system” (2014). [5]Dong et al describedAn Investigation on the Dynamic Stability of Scissor Lift. [6]]Richard E.Cullity, “scissor lift apparatus for work platforms and the like”(1995). [7] Marvelous Automatic Attic Stairs Jan 4, 2019 [8] “Design, Analysis and Development of Multiutility home equipment using Scissor Lift Mechanism”, Divyesh Prafulla Ubale, et al, International Journal of scientific research and management (IJSRM), Volume-3, Issue-3, Pages- 2405-2408, 2015. [9] “Design and Analysis of Hydraulic Pallet System in Chain Conveyor”, Setu Dabhi, et al, IJRET: International
  • 7. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072 © 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1199 Journal of Research in Engineering and Technology eISSN: 2319-1163 ISSN: 2321-7308. [10] “Finite Element analysis of Frame of Hydraulically Operated Beam Lifting Machine” S. B. Naik, et al, International Journal For Technological Research In Engineering Volume 2, Issue 8, April-2015 ISSN (Online): 2347 – 4718 [11] Design and analysis of an aerial scissor Lift, M. Abhinay, P.Sampath Rao,), SSRG International Journal of Mechanical Engineering (SSRG-IJME) – volume1 issue 5 September2014 Mechanical Dept, VREC, Nizamabad- 503003 [12]“Design & Analysis of Hydraulic Scissor Lift” M. Kiran Kumar1, J. Chandrasheker2, Mahipal Manda3 , D.Vijay Kumar4, International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 03 Issue: 06 June-2016 www.irjet.net p-ISSN: 2395-0072 [13] Design And Analysis Of An Aerial Scissor Lift, Jaydeep M. Bhatt, Milan J. Pandya, Journal Of Information, Knowledge And Research In Mechanical Engineering, Issn 0975 – 668x| Nov 12 To Oct 13 | Volume – 02, Issue – 02 [14] M. Ahmed, W.G. Wei, Study on Automated Car Parking System Based on Microcontroller, IJERT, Vol. 3 Issue 1, January-2014. [15] “Automatic Multivariate Liquid Filling System & Conveyor Control Using PLC & SCADA” , DherajPongalu, Prof. S. R. Suralkar , International Journal of Emerging Technology and Advanced Engineering (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 12, December 2014) [16] H Ahuja, A Singh, S Tandon, S Srivastava, & S Pal. Automatic Filling Management System for Industries. International Journal of Emerging Technology and Advanced Engineering. Vol. 4, Special Issue 1, February, 2014. [17] Arturo Valencia Ochoa Jaime Antonio Uribe “Scissors lift platform with electronic control”(1997). [18] Enoch L. Newlin “Scissor lift mechanism employing telescopable electro-mechanical based lift actuation arrangement”(2000). [19] Donald Watkins “Scissor lift mechanism” (2004). [20] Mahmood Ronaghi, John Z. Wu, Christopher S. Pan, James R. Harris, Daniel Welcome, Sharon S. Chiou, Brad Boehler and Ren G. Dong“An initiative to model static stability”(2009) . [21] Ren G. Dong, Christopher S. Pan, Jared J. Hartsell, Daniel E. Welcome, Tim Lutz, Anne Brumfield, James R. Harris, John Z. Wu, BryanWimer, Victor Mucino, Kenneth“An investigation on the dynamic stability of scissor lift” (2012). [22] M. J. Burkart, M. McCann and D. M. Paine, “Aerial Work Platforms, in Elevated Work Platforms and Scaffolding,” McGraw-Hill, New York, 2004. [23] S. Mohan and W. C. Zech, “Characteristics of Worker Accidents on NYSDOT Construction Projects,” Journal of Safety Research, Vol. 36, No. 4, 2005, pp. 353-360. doi:10.1016/j.jsr.2005.06.012. [24] M. McCann, “Death in Construction Related to Personnel Lifts, 1992-1999,” Journal of Safety Research, Vol. 34, No. 5, 2003, pp. 507-514. doi:10.1016/j.jsr.2003.07.001. [25] C. S. Pan, A. Hoskin, M. McCann, D. Castillo, M. Lin and K. Fern, “Aerial Lift Fall Injuries: A surveillance and Evaluation Approach for Targeting Prevention Activities,” Journal of Safety Research, Vol. 38, No. 6, 2007. [26]NFPA 1931, Standard on Design of and Design Verification Tests for Fire Department Ground Ladders, contains the requirements for the design and manufacturer’s testing of ground ladders [27] NFPA 1932, Standard on Use, Maintenance, and Service Testing of Fire Department Ground Ladders, provides the requirements for both maintaining and service testing ground ladders. [28] NFPA 1901, Standard for Automotive Fire Apparatus, set the minimum lengths and types of ladders to be carried on all pumper or engine companies (one 10’ folding ladder, one 14’ roof ladder, and one 24’ or larger extension ladder). [29] “Design, Manufacturing & Analysis of Hydraulic Scissor Lift”, Gaffar G Momin, et al,International Journal Of Engineering Research And General Science Volume 3, Issue 2, Part 2, March-April, 2015,ISSN 2091-2730. [30] Scissor Lift Tech Handbook, Omni metacraft [31] Lift and Escalators: Basic Principles and Design, Dr. Sam C M Hui Department of Mechanical Engineering The University of Hong Kong. [32] A Study In Lift Design9,000 Pound Capacity Four‐ Post Series Models: Hd‐ 9st Hd9, Ansi/Ali Alctv‐ 2006 Certified Product .