2. Hoisting Machinery & Equipments Notes

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Subject - Material Handling Systems (ME 40042 / MA/MP 40042)
Branch - Mechanical Engineering
Semester - 4th Semester

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Hoisting Machinery & Equipment

Hoisting machinery and equipment are used for lifting, lowering, and transporting heavy loads in various industries, construction sites, warehouses, and manufacturing plants. These machines help reduce manual labor and improve efficiency in material handling.

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2.1 Types of Hoists – Construction and Working

A hoist is a mechanical device used to lift or lower a load using a drum or lift wheel around which a rope or chain is wrapped. Hoists can be manually operated, electrically powered, or pneumatically driven.

1. Lever Operated Hoist

• Construction:

  • Made up of a lever, ratchet mechanism, load chain, and lifting hook.

  • Uses a ratchet and pawl mechanism to lift the load step by step.

• Working:

  • The operator moves the lever back and forth, which rotates a gear and lifts the chain.

  • Suitable for lifting medium to heavy loads in tight spaces.

• Application:

  • Used in factories, construction sites, and maintenance work.

2. Portable Hand Chain Hoist

• Construction:

  • Consists of a hand chain, gear system, load chain, and lifting hook.

  • No external power is required; it operates manually.

• Working:

  • The operator pulls the hand chain, which rotates a gear system and lifts the load chain.

  • Used for lifting light to medium loads.

• Application:

  • Suitable for warehouses, workshops, and temporary lifting jobs.

3. Electric & Pneumatic Hoists

• Construction:

  • Consists of an electric motor or air compressor, lifting drum, wire rope or chain, and safety brakes.

• Working:

  • Electric hoists: Use an electric motor to drive gears that rotate the drum and lift the load.

  • Pneumatic hoists: Use compressed air to power a motor that lifts the load.

• Application:

  • Used in heavy-duty industries, factories, shipyards, and assembly lines.

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2.2 Types of Cranes – Construction and Working

Cranes are lifting machines used to move heavy loads horizontally and vertically. They can be stationary or mobile, depending on the application.

1. Mobile Cranes

• Construction:

  • Mounted on wheels or crawler tracks.

  • Has a telescopic or lattice boom, counterweights, and hydraulic lifting mechanism.

• Working:

  • Uses hydraulic cylinders and pulleys to extend/retract the boom and lift loads.

  • Can move on roads and rough terrain.

• Application:

  • Used in construction sites, shipyards, and mining operations.

2. Bridge Cranes (Overhead Cranes)

• Construction:

  • Has two parallel runways with a traveling bridge.

  • A hoist is mounted on the bridge and moves along the runway.

• Working:

  • The bridge moves forward and backward while the hoist lifts and lowers loads.

  • Operated via remote control or control cabin.

• Application:

  • Used in factories, warehouses, and steel mills for moving heavy materials.

3. Cable Cranes

• Construction:

  • Uses steel cables stretched between towers.

  • A trolley moves along the cables, carrying loads.

• Working:

  • The trolley moves along the cable to transport materials over long distances.

• Application:

  • Used in dams, bridges, and mountainous terrain where regular cranes cannot operate.

4. Cranes Traveling on Guide Rails

• Construction:

  • A crane is mounted on rails that guide its movement.

  • It has a fixed or telescopic boom and a lifting hoist.

• Working:

  • The crane moves along the guide rails while lifting and transporting loads.

• Application:

  • Used in shipbuilding yards, ports, and railway yards.

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2.3 Elevating Equipment – Construction and Working

Elevating equipment is used to lift materials and people to different heights in industries, warehouses, and buildings.

1. Stackers

• Construction:

  • Has a vertical mast, lifting forks, hydraulic system, and wheels.

  • Operated manually, electrically, or hydraulically.

• Working:

  • The forks lift and lower palletized goods using a hydraulic system.

• Application:

  • Used in warehouses for stacking pallets and goods.

2. Industrial Lifts

• Construction:

  • A platform enclosed by a safety cage, supported by a lifting mechanism.

  • Powered by hydraulic, electric, or mechanical systems.

• Working:

  • Moves vertically to transport heavy loads between different floors.

• Application:

  • Used in factories, mines, and large warehouses.

3. Freight Elevators

• Construction:

  • Large, enclosed cabins with heavy-duty doors and a lifting mechanism.

• Working:

  • Uses hydraulic or electric motors to lift cargo between floors.

• Application:

  • Used in shopping malls, factories, and storage facilities.

4. Passenger Lifts (Elevators)

• Construction:

  • Consists of a cabin, counterweight, guide rails, motor, and control panel.

• Working:

  • Operates using electric motors and pulleys to move people up and down floors.

• Application:

  • Used in offices, residential buildings, and hospitals.

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Conclusion

Hoisting machinery and elevating equipment are essential for safe and efficient material handling in various industries. Different types of hoists, cranes, and lifts are used depending on the load type, height, and working environment.