BIRLA INSTITUTE OF TECHNOLOGY AND SCIENCE, PILANI
A REPORT ON
Vertical Lift Bridge Prepared by
Manu Dixit Rajiv J Nagpal Vijay Varma Prankur Sharma Juhi Kapoor Ravin Arora
(2009B5A4655P) (2009B5A4655P) (2009B5A4472P) (2009B5A4472P) (2009B5A4657P) (2009B5A4657P) (2009B3A4622P) (2009B3A4622P) (2009B1A4790P) (2009B1A4790P) (2010A4PS573P) (2010A4PS573P)
Submitted to Dr. K.S. Sangwan
In partial fulfillment of the requirements of the course ME C342 Production Techniques
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ACKNOWLEDGEMENTS We owe a great many thanks to many people who helped and supported us during the preparation of this project report. First of all, we would like to thank Prof. K.S. Sangwan for giving us the opportunity and the requisite facilities to complete our project within the stipulated time. Without him, all this would not have been possible. Sincere thanks are due to the people at BITS Workshop. We would like to convey the deepest appreciation to Mr. Mahendra Kumar Saini who continuously provided us not only with tools but also his valuable suggestions for the betterment of our project. Next are the store people who provided whatever material we demanded. Our sincere thanks goes to Mr. Madanlal Jangir, Senior Store keeper; Mr. Vishambharlal Chauhan, Mr. Vikas Soni and Mr. Harsh Kumar Sharma, Mr. Raju Saini. Sincere thanks are also due to all the skilled workers on the shop floor for their wholehearted cooperation in solving our doubts and guiding us along on the work processes. Mr. Mahendra Singh and Mr. Banwarilal Saini at Weld shop also deserve an appreciation at the completion of our project. Without their guidance and persistence this experience might not be a successful one. We would like to thank them for giving us the opportunity to work and experiment with almost all the production techniques at workshop.
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TABLE OF CONTENTS S.No. 1. 2. 3. 4. 5. 6. 7.
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TOPIC Introduction Bridge Span Bridge frame Chain Drive Mechanism Problems Faced while working Conclusions References
Page no. 4-6 7-8 9-11 12-14 15 16 17
1. INTRODUCTION A vertical-lift bridge or lift bridge is a type of movable of movable bridge in which a span rises vertically while remaining parallel with the deck which ensures passing of ships underneath. They cost less to build for longer moveable spans. The counterweights in a vertical lift are only required to be equal to the weight of the deck. Thus heavier materials can be used in the deck, and so this type of bridge is especially suited for heavy railroad use. It is also more energy efficient, requiring comparatively less power to lift the bridge. The project is a prototype of such a bridge and utilizes a chain drive mechanism to lift the middle span of the bridge.
Lift bridges state of the art Among mobile bridges, lift ones appear as the right answer when relatively long spans are needed. Bascule bridges or rotating ones are more limited, limited, because of their overhanging overhanging decks. In France the existing lift bridge with the the lifting span. longest span is “Recouvrance” Bridge in Brest, with an 87.5 meters lifting But most large bridges bridges of this kind are located in New Jersey, Jersey, USA where many waterways allow maritime maritime traffic. The longest lifting span in in the world belongs to Arthur Kill Bridge with 170 meters, no longer in operation. Another significant structure structure is the Gil Hodges Memorial Bridge , with with a main span in the range of 160 meters.
METHODOLOGY When a handle attatched at the bottom is rotated the middle span is lifted by 2 ropes, 1 at each extremity. The ropes are attached to the 2 S-hooks which raise the bridge span. The ropes which go over the side pulleys wrap around the central pulley thus shortening the length of ropes and causing lifting.
MATERIALS USED
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Mild Steel rods
MS plates, angles and screws
Wood
Aluminium sheet
PROCESSES REQUIRED Lathe Operations, Drilling, Welding, Grinding, cutting
TECHNICAL SPECIFICATIONS The provisional specifications of the vertical-lift bridge are specified as below:
The length of the bridge frame is 2 ft.
The height of the bridge frame is 3 ft.
The aluminium strips that form the truss are 0.5 inch in thickness and the height of the middle span is 7 inches.
Fig 1.1
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Fig 1.2
The main parts and components have been discussed in the following sections. The vertical-lift bridge is divided into the following 3 broad categories:
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Bridge Span
Bridge Frame
Chain Drive Mechanism
2. BRIDGE SPAN Manufacturing processes used:
Cutting/sawing
The bridge span includes the 1. Middle Span Function: the base of the bridge which is to be lifted. Material: wood, aluminium, mild steel Dimensions:
Wooden base length of 21in and width 8 inches.
Aluminium strips of 0.5 inch thickness
2 wooden Top chords of length 21in and thickness 1 inch.
2 MS connecting rods
Sequence of operations: 1. Obtained wood from scrap. 2. The required dimensions of the base and the top chords were obtained using a hacksaw. 3. 2 holes each on the 2 chords were drilled. 4. The strips were cut from an aluminium sheet using the shape cutting machine and they function as the webs of the truss. 5. The strips were hammered onto the base and the chords to form the struss. 6. The top chords were machined on the lathe using the turning o peration to get the desired diameter and then fixed into the holes to connect the top chords. 7. Finishing was done by applying primer and finally paint was applied. 2. Side Spans Function: the extensions of the span on either side of the middle span. 7
Material: wood, aluminium Dimensions:
2 Top chords: Length of 9.5 inches, height=1.5 inches, width=1 inch
Sequence of operations: 1. Obtained wood from scrap. 2. The required dimensions of the base and the top chords were obtained using a hacksaw. 3. 2 holes each on the 2 chords were drilled. 4. The strips were cut from an aluminium sheet using the shape cutting machine and they function as the webs of the truss. 5. The strips were hammered onto the base and the chords to form the struss. 6. The top chords were machined on the lathe using the turning operation to get the desired diameter and then fixed into the holes to connect the top chords. 7. Finishing was done by applying primer and finally paint was applied.
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3.BRIDGE FRAME Fig 3.1
FIG 3.2
Manufacturing processes used:
Welding
Turning
Drilling
1. L-Brackets Function: form the support against which the middle span of the bridge rises. Quantity: 4 Material: Mild Steel Dimensions: height = 3ft ,thickness=0.25 in, width=1 in 2. Supporting plates Function: hold the L-brackets in vertical position together. Quantity: 12 9
Material: Mild steel Dimensions:
6 plates of length=8 in and thickness=1 in
6 plates of length=2ft and thickness=1 in
3.Pulleys
Middle pulley Function: causes the movement of the side pulleys which in turn cause the ropes to pull the bridge upwards. Material: wood Quantity: 1 Dimensions:
3 in diameter, thickness of the 2 grooves=0.25 in, total width of pulley=1.75in
Side pulleys Function: cause the ropes to lift the bridge by wrapping the r opes in the Vgroove machined on the pulley surface. Material: wood Quantity: 2 Dimensions: 3 in diameter, width = 1 in
4. Connecting rods Function: support the pulleys Material: MS Quantity: 3 10
Dimensions: diameter=0.5 in, length=6 in
Sequence of operations: 1. MS angles and plates were obtained from the scrap. 2. The support plates were welded onto the angles using arc welding.(fillet weld). 3. Holes were drilled into the frame for the 3 connecting rods as well as the MS rod fixed at the bottom of the frame over which the the sprocket gear rotates. 4. The connecting rods were machined on the lathe using the turning operation to the diameter of the hole. 5. Holes were drilled into the rods and pins were used to fix the rods in place and prevent axial movement. 6. The sprocket was welded onto the middle connecting rod.(tac welds)
Sequence of operations for pulleys
1. A rectangular block of wood was obtained from the scrap. 2. The block was machined to get a cylindrical block using the wood cutting machine.
3. The wooden cylinder was divided into 3 parts. 4. Each part had a hole drilled into it using the drilling machine. 5. The V-grooves were machined onto the surface using a lathe. The pulleys were attached to the rods and the rods were fixed using washers and pins.
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4.CHAIN DRIVE MECHANISM Fig 4.1
Fig 4.2
Manufacturing processes used:
Drilling
Boring
welding
1.Sprocket gear Function: cause the movement of the middle pulley. Material: MS
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Quantity: 2 Dimensions:
gear at the bottom has diameter 4 in with 22 teeth
gear attached to the middle pulley has dia 4 in with 18 teeth
2.Hollow pipe/Bearing/Connecting rod Function: cause the movement of the sprocket at the bottom Material: MS Quantity AND Dimensions: 1 bearing of dia 1.25 in, 1 connecting rod of dia 0.5 in and length 8 in
3.Chain Function: goes over the sprocket gears to cause their movement.
4.Handle Function: used to rotate the sprocket gears Material: MS
5.Ropes Function: lift the bridge to the desired level Material: jute Quantity: 2
6.S-hooks Function: lift the bridge to the desired level Material: MS Quantity: 2 13
Dimensions:
dia of loop=0.5 in
Sequence of operations: 1. The bushings were welded onto the sprockets. 2. For the bottom sprocket bearing was press fitted onto the pipe and the sprocket was fixed over the pipe. The pipe with the bearing was fixed over the connecting rod. 3. For the sprocket gear at the top a cylindrical blank was turned to fit into the bushing. 4. A hole of diameter 0.5 in was drilled into it. The cylindrical rod was welded onto the bushings and then onto the connecting rod for the middle pulley. 5. Ropes were nailed onto the central pulley and passed over the side pulleys. 6. The ropes were attached to the chord connecting rods through S-hooks of 0.5 inch dia. 7. The chain was put over the sprockets. 8. The handle was welded onto the pipe.
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5.Problems faced while working
Wobbling occurred while machining machining a long rod on the lathe machine leading to a very high eccentricity.
Large depth of cut in turning led to poor surface finish of connecting rods.
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Lesser bridge thickness led to chipping of wood due to hammering.
6.CONCLUSION All the objectives and likewise procedures were completed to make this screw jack powered hand forklift. The production techniques used in the process were cutting, welding, drilling, grinding, threading, turning, and mechanical fastening. The forklift serves its purpose of lifting considerable amount of weights and transporting them over short distances. The dimensions were decided keeping in mind comfort and ease of transportation of the load. We successfully implemented various production techniques to achieve the objective of our project.
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7.REFERENCES 1. www.stanford.edu/~piyushk/The% www.stanford.edu/~piyushk/The%20Kattwyk%20 20Kattwyk%20Bridge.pdf Bridge.pdf 2. www.engineeringminiprojects www.engineeringminiprojects.com/mechanical .com/mechanicalprojects-mechanic projects-mechanicalalengineering-projects-topics/2012/ 3. Shigley. Mischke. Budynas & Nisbett, “Mechanical Engineering Design”(2008) Ninth Edition, Tata McGraw Hill Pvt. Ltd.
4. Amitabha Ghosh, Asok Kumar Mallik(1985) Manufacturing Science, EastWest Press Private Limited
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