The basic and simplest idea behind this micro headroom jib crane design is , keeping substantial and weighty components like Motor,Gearbox,Drum assembly and breaks etc on rear side, it seems logically simple , As usual the main motor operating Drum and reliving cables to hoist operation is fine, But when we design, we found the Cross travel is not synchronizing with the main hoist cable reliving, what happening, cable is loosened or tightened, so load going down while Cross travel operation is required

1. RAJANI HOIST & CRANES PRESENTS
Micro headroom
JIB CRANE
Book
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M I C R O H E A D R O O M J I B C R A N E C O N C E P T S , D E S G I N A N D P R O T O T Y P E
3000 Kg payload design proposal
DOUBLE GEAR
Transmission Elements
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 Double Gear transmission elements
240/2,Clover Building II Floor,Thambu Chetty Street,Broadway,Chennai,TamilNadu,INDIA
Phone +91-44-25340618• Fax +91-44-25341022• Mob +91-9791222047
E-mail: ceo@doublegear.co.in, www.doublegear.co.in
Over 20 years, DOUBLE GEAR has earned a nationally recognized reputation for
expertise in power transmission engineering and automation, cranes, hoist and crane duty
modular gearbox design would helps engineers and manufacturers to construct robust
infrastructures without any complications and completely tested & trusted.

3. i
WELCOME
Good Morning, I am Nagarajan from INDIA doing material handling
equipment manufacturing, supplying and exporting, I always used to dream
something innovative way to develop concepts and ideas in my field of
engineering
So for I have designed various components for the cranes, For example
gearboxes, Electrical wire rope Hoists, electrical safety circuits and accessories.
Among these, my Drum rope guide design, Cross pulling prevention
Mechanisms, hypocycloid limit switches are very famously accepted in my
colleagues organizations
This time I have developed micro headroom JIB crane, which has been
proposed to a customer, who long time has requested, Since they are operating
cargo goods transportation business, they have very tough time to load or
unload heavy parcels from the container lorry. Inside the container , headroom
clearance will be less than 10 feet, so any normal type Crane equipments cannot
handle this type of operations efficiently. Every time they would hire mobile
crane vechile to load/unload their goods, it is time consuming and costly too
I developed this idea and proposed them, by the way of implementing MICRO
HEAD ROOM hoist, All mechanical parts like motor, Gearbox, Drum, Guides
and Breaks are kept on rear side , While the boom and trolley along with hook
would extrude in to the container. It seems sounds and innovative, we are
waiting foe the clearance from their management to go ahead to produce.
Just I want to share my ideas with you for improvements and your valuable
opinions, please share if you like this
Thanks
Nagarajan.B +91 9791222047 ( CEO)
rajanihoistandcranes@gmail.com
Friday, March 8, 2019

4. ii
SECTION 1 Basic idea
Picture showing rear side components in cut through sections for understandings
The basic and simplest idea behind this micro headroom jib crane design is ,
keeping substantial and weighty components like Motor,Gearbox,Drum
assembly and breaks etc on rear side, it seems logically simple , As usual the
main motor operating Drum and reliving cables to hoist operation is fine, But
when we design, we found the Cross travel is not synchronizing with the main
hoist cable reliving, what happening, cable is loosened or tightened, so load

5. iii
going down while Cross travel operation is required

6. iv
SECTION 2 how it works
Picture shows how the Motor is synchronized with hoisting and Cross travel motion
The main Motor (5HP) is first connected to Differential gearbox , which
will synchronize the Cross travel while the main Hoist motion is
connected with Helical gearbox with Drum
By using the differential
gearbox, (Like the motor vehicle
rear side wheels are synchronized
while in turning) The main motor
rotational force will be
redirected to the connecting
screw rod, which in turn move
hook trolley front and back

7. v
SECTION 3 A close look of differential Gearbox
A close look of the differential gearbox assembly
The main motor Shaft is Connected with Differential gearbox worm shaft
along with main hoist gearbox input pinion , Inside the differential
gearbox worm gear, Bevel gear assembly will rotate differentially as per the
either side break or load is applied.
When the user requires only Hoisting operations like UP/DOWN , Screw
road break will hold the torque, subsequently the gearbox will redirect the
Cross travel movement in to the null Shaft ( Noting is connected except
break). When user initiates Cross travel, The null Shaft will hold by applying
the break, while screw Shaft will rotate so The trolley will move front and
back
While trolley moving front and back, the main Gearbox will rotate the
drum to loosing/tightening the rope to maintain the load on stable
position

8. vi
SECTION 4 How the Trolley and boom works
The Screw Shaft has been designed to synchronies’ the trolley speed
according to the pitch and differential gearbox reduction ratio. NOTICE :
This JIB crane is designed for Single fall hook, if required double fall, the
screw shaft also has to be replaced with correct thread pitch
Only main motor will operate hoisting and Cross travel. There is no
additional motor for cross travel motion. This is the highlight of design
For safety purpose the screw shaft is placed inside of the boom. It should
be maintained with proper lubrication for smooth and longer life

9. vii
A close look of the trolley and bottom block
Since the hoisting operation and trolley movement are
synchronized, if user press both UP/DOWN and LEFT/RIGHT
buttons simultaneously, Cross travel only works and hoisting
operation will be ignored. Care should be exercised when trolley
moves either side end . by installing additional limit switches we
can safely control the user mishandling.
This JIB crane is designed for manual swivel operation. Knotting
a rope at the boom end, user can do rapid swivel operation

10. viii
Rope guide has been synchronized with main drum by sprockets and
chain along with screw shaft to maintain groove to rope seating. Since
heavy thrust load is experienced in the rope guide, it has been designed
sliding “X” Groove
SECTION 5 Conclusions
Advantages:
• Head room requires as low as 200 mm (8” inches)
• Less beam load ( Bending) due to rear side equipments mounting
• Only Single motor required for both motions
• Load counter balanced with self weight (No overhung load)
• Payload as much as high (2 times service factor)
• Zero present 0% Slipper in cross travel movement
• Easy to upgrade Ancillary speed operation
• Repairing and maintenances are easy
• Cost effective

11. ix
Disadvantages (I feel some improvements requires)
1. More moving parts
2. More Rope fatigued
3. Proper Lubrication required
The actual performances of this crane could be justified after
manufactured and tested, Friends Please give your suggestions and
opinions for improvements
I have future plans for implementing electrical / Rapid Manual swivel
movements, manual micro adjustments for Hoisting & Cross travel also.
Definitely I would share my experience. Stay touched
Please Note: This a prototype proposal. Still not verified & tested, If you
like it, Please request me, I will send you manufacturing Drawings and
specifications. Try to do improve yourself and share your experience &
knowledge
Thanks For Reading
Nagarajan
CEO, Rajani Hoist and cranes
BANGALORE , INDIA