2. BASIC PRINCIPLES IN BUILDING
CONVEYING SYSTEMS
Building conveying systems mechanically move occupants
and goods. In most buildings, these systems include
passenger and freight elevators, dumbwaiters, escalators,
moving ramps and walkways, and lifts for people and
wheelchairs. Business and industrial operations may require
specially designed material handling equipment (i. e.,
conveyors, chutes, and pneumatic tube systems),hoists,
cranes, and scaffolding. Facilities on large sites may have
monorails and other types of people movers.
3. BASIC PRINCIPLES IN BUILDING
CONVEYING SYSTEMS
Manually operated elevators were first used for lifting freight in
warehouses and manufacturing plants as early as the 1600s. They began
as simple rope or chain hoists that moved an open platform. In
1852,Elisha Otis introduced the safety elevator, which prevented the fall
of the elevator cab if the cable broke. Otis’s safety device consisted of a
knurled roller located below the elevator platform and a governor
device that monitored descending speed. The safety device locked when
the elevator descended at a higher than normal speed. It was this safety
feature that made the elevator a safe conveying system for building
occupants, which then made skyscrapers achievable.
6. PHOTO BELOW SHOWS AN ELEVATOR
CAR WITH HOIST WAY DOORS OPEN.
First-floor entrances to two elevator cars (doors
closed).Note the hall lanterns between the doors (above
sign).The hall station is below the sign.
7. THE TWO BASIC TYPES OF
ELEVATOR TECHNOLOGIES
hydraulic
traction
8. TYPE AND DESIGN SPEEDS FOR
ELEVATORS ARE COMPARED IN TABLE
BELOW.
10. BASIC COMPONENTS OF A HYDRAULIC
ELEVATOR SYSTEM ARE SHOWN IN
FIGURE BELOW.
.
11. HYDRAULIC ELEVATORS
It consists of a hydraulic jack (cylinder and plunger); a pump, powered
by an electric motor, that increases the pressure in the hydraulic fluid; a
control valve between the cylinder and reservoir controls the pressure
in the jack; and a fluid reservoir (tank). It operates when the pump
draws oil from the reservoir, pressurizes it, pushing the oil through the
oil line to the jack, and driving the elevator car upward. A release of fluid
through the control valve and back to the reservoir decreases oil
pressure, which allows the plunger and connected elevator car to move
downward.
13. VARIATIONS OF BASIC
TYPES OF ELEVATORS.
Conventional (Holed) Hydraulic Elevator
Traction Elevator
Holeless Hydraulic Elevator
Roped Hydraulic Elevator
14. HYDRAULIC ELEVATORS
On a conventional (holed) hydraulic elevator, an inground hydraulic jack
lifts the elevator car. A long plunger requires a deep hole below the
bottom landing. The hole is usually drilled into the ground and cased
with a plastic or metal casing before the building is erected.
15. HYDRAULIC ELEVATORS
A telescopic hydraulic elevator has a telescoping
plunger consisting of concentric tubes that slide within
one another, allowing a shallow hole below the lowest
floor.
Conventional (holed) hydraulic elevators are the most
balanced type of hydraulic elevator configuration
because the lifting point on the bottom of the elevator
car is centered.
16. HYDRAULIC ELEVATORS
Holeless hydraulic elevators have one or two jacks situated
beside the rails that lift the platform. Because they do not
require holes to be dug for the hydraulic jack(s), they are
referred to as “holeless.” The dual or twin jack configuration
can have two (front and rear) entrances, while the single
jack configuration can only have one (front) entrance.
18. HYDRAULIC ELEVATORS
Roped hydraulic elevators use a combination of
both ropes and hydraulic power to raise and lower
cars. They typically consist of a cantilevered car that
is lifted by ropes that pass over a sheave (pulley)
fastened to the top of a hydraulic plunger. As the
plunger rises, so does the elevator car. Single rope
configuration cannot have rear entrances.
20. TRACTION ELEVATORS
Traction elevators have a drive
machine with an electric motor and
pulley-like (grooved) drive sheave
that holds cables that move the
elevator car up or down.
22. TRACTION ELEVATOR
Steel cables, called hoisting ropes, support the elevator and counterweight during
normal operation. There are typically three to eight cables for each elevator. Most
traction elevators generally use wire ropes that are 1⁄4 to 11⁄4 inches (6 to 32 mm)
in diameter and are composed of multistrand soft steel wire wound around a hemp
or polymeric core. Traditionally, the 8 19 wire rope (eight strands with 19 wires per
strand) pattern was used, but this is being replaced with modern patterns. Wire
ropes must match the drive sheave perfectly to ensure that they have a long life. The
counterweight is a set of steel or iron plates fastened to one end of the hoisting
rope that counterbalances the car. It is weighted to be equal to the car’s dead weight
plus 40 to 50% of car load capacity. The weight of the car and counterweight presses
ropes into grooves on a drive sheave. The friction between the hoisting ropes and
the drive sheave is used to move the elevator car with the cable.
24. CLASSIFICATIONS OF
ELEVATORS
Passenger elevators are designed to carry people and small packages.
Freight elevators are used to carry material, goods, equipment, and
vehicles, rather than people.
A dumbwaiter is a small freight elevator used to transport lightweight
freight such as food, laundry, books, records, and other small items.
A manlift is an elevator installed in a variety of structures and locations
to provide vertical transportation of authorized personnel and their
tools and equipment only.
25. 2. ESCALATORS
An escalator is a power-
driven, continuously moving
stairway system used for
transporting people.
28. ESCALATOR COMPONENTS
Balustrade is the side of an escalator system. It
extends above the steps and includes skirt panels,
interior panels, decks, and handrails.
Moving handrail provides a handhold that riders use
for balance and safety on their ride up or down. The
handrail is powered by the same system that powers
the steps. It moves along the top of the balustrade
in synchronization with the steps.
29. COMPONENTS OF AN
ESCALATOR.
Truss is an assembly of structural steel that serves to support
the escalator load. Ends of the truss are attached to top and
bottom landing platforms. The machinery of an escalator is
hidden beneath its steps and within the truss. At the top of the
escalator, housed in the truss, is an electric motor that runs the
drive gears. There are two drive gears on either side at the top
and two return gears on either side at the bottom. These gears
have chains that loop around the gears and run down each side
of the escalator. Connected to each step, these chains help the
steps make their way up, or down, the escalator.
31. A LOWER LANDING OF AN ESCALATOR. NOTE HOW THE
STAIRS RAISE AT THE BEGINNING OF THE ESCALATOR. AN
EMERGENCY STOP SWITCH EXTENDS FROM THE RIGHT
HANDRAIL.
•
32. AN UPPER LANDING OF AN ESCALATOR.
NOTE HOW THE STAIRS FOLD IN AT THE
TOP OF THE ESCALATOR.
.
34. 3. WALKWAYS AND RAMPS
A moving walkway is a power-driven, continuous,slow-moving
conveyor belt that transports people horizontally.They are also
called moving sidewalk, moving pavement, walkalator, and
travelator. An inclined moving walkway, also called a moving
rampor power ramp, is a moving walkway that transports
people on an incline, up to a 12° angle of inclination. Moving
walkways are more accessible to those in wheelchairs, as they
are usually thought easier to use than getting in and out of
small elevators.
38. A PALLET-TYPE WALKWAY IS A CONTINUOUS
SERIES OF FLAT METAL PLATES, CALLED PALLETS,
THAT ARE JOINED TOGETHER TO FORM A
WALKWAY.
.
39. TWO TYPES OF WALKWAY
TECHNOLOGIES
pallet type
moving belt.
40. PALLET-TYPE WALKWAY
MOVING BELT WALKWAY
The pallet-type walkway is a continuous series of flat
metal plates, called pallets, that are joined together
to form a walkway. Usually there is a metal or
rubber surface (extra traction).
Moving belt walkway systems are comprised of a
mesh metal or rubber belt with a rubber walking
surface that move over metal rollers.
42. WHEELCHAIR LIFT
A wheelchair lift is a powered device designed to
raise a wheelchair or scooter and its occupant to
overcome a step or similar vertical barrier, usually 6
ft (1.8 m) or less. They often are designed to
accommodate just one person in a wheelchair or
scooter at a time. Commercial lifts are designed to
raise a wheelchair or scooter and its occupant up to
one story (about 12 ft>4 m).
45. STAIR LIFT
A stair lift will carry a user safely
up stairs. To use a stair lift, the user
sits on the lift’s seat; the seat will
then transfer the user up or
downstairs via a staircase-
mounted track.
46. CAR LIFT
A car lift is installed in small parking garages where ramps are
not feasible. The platforms are raised and lowered hydraulically
and are connected to steel chain gears. In addition to the
vertical motion, the platforms can rotate about its vertical axis
(up to 180°) to ease driver access and/or accommodate
building plans. In selecting lift equipment, the building designer
typically relies on specifications available from equipment
suppliers.
47. PEOPLE MOVERS
An automated people mover (APM) is a fully automated,
grade-separated mass transit system. An APM system typically
serves relatively small facilities such as airports, downtown
districts, or theme parks, but is sometimes applied to
considerably more complex automated systems. It may use
technologies such as monorail, duorail, automated guideway
transit, or magnetically levitating (maglev) method. Propulsion
may involve conventional on-board electric motors, linear
motors, or cable traction. APMs are common at large airports
in the United States.
48. MATERIAL-HANDLING
EQUIPMENT
Material-handling equipment is a mechanical device used to
move and store materials and goods. This equipment consists
of trolleys, conveyors, forklifts, automated storage/retrieval
systems, cargo and baggage handlers, carousels, rail-guided
vehicles, automated guided vehicles, intelligent flexible
modular conveyors, pick-and-place units, and overhead hoists
and cranes. In selecting material-handling equipment, the
building designer typically relies on specifications available
from equipment suppliers.
49. THE CONVEYOR BELT OF AN AUTOMATIC
BOOK-SORTING SYSTEM AT A PUBLIC
LIBRARY.
.
50. PATERNOSTER
A paternoster is a special type of elevator consisting
of a constantly moving chain of boxes. A similar
concept moves only a small platform, which the
rider mounts while using a handhold and was once
seen in multistory industrial plants. Passengers can
step on or off at any floor they like. Today, the
installation of new paternosters is no longer allowed
because of to their inherent danger.
51. STUDY QUESTIONS
1. Describe the hydraulic elevator.
2. Describe the traction elevator.
3. Explain the differences between the conventional (holed) hydraulic
elevator, the telescopic hydraulic elevator, and the holeless hydraulic
elevator.
4. Describe and distinguish between the following components of an
elevator system:
a. Car
b. Platform
c. Cab
52. STUDY QUESTIONS
5. Describe the following components of an elevator system:
a. Pit
b. Penthouse
c. Landing
6. Describe the following components of an elevator system:
a. Hoistway
b. Blind hoistway
c. Hoistway doors
53. STUDY QUESTIONS
7. Describe the following components of an elevator system:
a. Elevator controller
b. Car operating station
c. Hall station
d. Traveling cable
8. Describe the following components of an elevator system:
a. Brake
b. Governor
c. Drive unit
d. Buffer
54. STUDY QUESTIONS
9. Describe the classifications of elevators based on use.
10. Describe an escalator.
11. Describe the following components of an escalator system:
a. Drive unit
b. Sprocket drive
c. Steps
d. Balustrade
e. Moving handrail
f. Truss
g. Emergency stop button
55. STUDY QUESTIONS
12. Describe the differences between the crisscross, single continuous,
continuous parallel, and noncontinuous parallel escalator systems.
13.What is the typical inclination angle of an escalator?
14. Describe a moving walkway.
15.What are the two types of walkway technologies?
16.What is a wheelchair lift?
17.What is the difference between a platform lift and a stair lift?
18. Describe a car lift.
19.What is a paternoster?
56. DESIGN EXERCISES
20. Using a stopwatch, time an elevator in a building. Determine the following:
a. Average time required for the door to close once a car operating station
button (i.e., floor button) is pushed
b. Average time required for the door to fully open once the car stops at the
floor
c. Average time the door remains open at a floor (from the time it is fully open to
the time it begins to close after a button is pushed)
d. The average time it took to go up one story, excluding wait time (start the
stopwatch as soon as the elevator starts to move, and stop it as soon as the
elevator stops at the floor)
e. The average time it took to go up one story, including wait time
f. The average time it takes to walk up one story by using the stairs
57. DESIGN EXERCISES
21. Using a stopwatch, time an elevator in a high-rise building (75
stories). Determine the following:
a. The average time it took to go up one story, excluding wait time
(start the stopwatch as soon as the elevator starts to move, and
stop it as soon as the elevator stops at the floor)
b. The approximate number of adults who can travel from floor to
floor in 5 min, if the elevator is fully
58. DESIGN EXERCISES
22. Using a stopwatch, time an escalator in a building. Determine the
following:
a. The average time it took to go up one story (start the stopwatch as
soon as you step onto the escalator, and stop it as soon as you step
off)
b. The approximate number of adults who can travel from floor to
floor in 5 min, if the escalator is fully used
