Definitions Of Various Hoist Terms

abnormal operating conditions

Environmental conditions that are unfavorable, harmful, or detrimental to or for the operation of a hoist, such as excessively high or low ambient temperatures, exposure to weather, corrosive fumes, dust laden or moisture laden atmospheres, and hazardous locations.

below-the-hook lifting devices

Devices that are not normally reeved onto the hoist rope or chain, such as hook-on buckets, magnets, grabs, and other supplemental devices used for ease of handling certain types of loads. The weight of these devices is to be considered part of the load to be lifted.

block loads

An action that facilitates the removal of slings or other lifting devices from under the load, accomplished by bringing the load to rest on wood, metal, or other spacers between the floor and load.

brake

A device on the hoist, other than a motor, used for retarding or stopping motion by friction or power means.

brake, holding

A friction brake for a hoist that is automatically applied and prevents motion when power to the brake is de-energized.

brake, mechanical load

An automatic type of friction brake in the hoist that is used for controlling loads in a lowering direction. This unidirectional device requires torque from the motor or hand chain wheel to lower a load but does not impose any additional load on the motor or hand chain wheel when the hoist is lifting a load. A mechanical load brake is a mechanical control braking means.

braking means

A method or device used for stopping or holding motion of the hoist by friction or power.

braking means, control

A method of controlling hoist speed by removing energy from the moving body or by imparting energy in the opposite direction.
braking means, countertorque (plugging) - A method of control by which the power to the motor is reversed to develop torque in the direction opposite to the rotation of the motor.

braking means, dynamic

A method of controlling hoist speed by using the motor as a generator, with the energy being dissipated by resistance.

braking means, eddy current

A method of controlling or reducing hoist speed by means of an energy induction load brake.

braking means, mechanical

A method of controlling or reducing hoist speed by friction.

braking means, pneumatic

A method of controlling or reducing hoist speed by means of a compressed gas.

braking means, regenerative

A method of controlling hoist speed in which the electrical energy generated by the motor is fed back into the power system.

chain guide

See guide, chain.

chain, hand

The chain grasped by a person to apply force required for the lifting or lowering motion of the hoist.

chain, load

The load-bearing chain in a hoist.

chain, roller

A series of alternately assembled roller links and pin links in which the pins articulate inside the bushings and the rollers are free to turn on the bushings. Pins and bushings are press fit in their respective link plates.

chain, welded link

A hoist chain consisting of a series of interwoven links formed and welded.

designated person

A person selected or assigned by the employer or the employer's representative as being competent to perform specific duties.

guide, chain

A means to guide the hoist load chain at the load sprocket.

hand chain wheel

See wheel, hand chain.

hoist

A machinery unit that is used for lifting or lowering a freely suspended (unguided) load.

lifting devices

Devices that are not normally reeved onto the hoist ropes or chain, such as hook-on buckets, magnets, grabs, and other supplemental devices used for ease of handling certain types of loads. The weight of these devices is to be considered part of the load to be lifted.

limit device

A device that is operated by some part or motion of a power driven hoist to limit motion.

limit device, primary upper

See primary upper-limit device.

load

The total superimposed weight on the hoist load block or hook.

load, rated

The maximum load for which a hoist is designated by the manufacturer or a qualified person.

load block

The assembly of hook or shackle, swivel, bearing, sheaves, sprockets, pins, and frame suspended by the hoisting rope or load chain. This shall include any appurtenances reeved in the hoisting rope or load chain.

load chain

See chain, load.

load suspension parts

The load suspension parts of the hoist are the means of suspension (hook or lug), the structure or housing which supports the drum or load sprocket, the drum or load sprocket, the rope or load chain, the sheaves or sprockets, and the load block or hook.

normal operating conditions

Conditions during which a hoist is performing functions within the scope of the original design.

overload

Any hoist load greater than the rated load.

overtravel restraint

A device used to prevent the hoists slack load chain from inadvertently being lowered out of the load sprocket.

parts (lines)

Number of lines of rope or chain supporting the load block or hook.

pendant station

Controls suspended from the hoist for operating the unit from the floor.

power transmission parts

The hoist machinery components including the gears, shafts, clutches, couplings, bearings, motors, and brakes.

primary upper-limit device

The primary upper-limit device is the first limit device that will be activated to control the upper limit of travel of the load block when a hoist is equipped with more than one upper-limit device

qualified person

A person who, by possession of a recognized degree in an applicable field or a certificate of professional standing, or who by extensive knowledge, training, and experience, has successfully demonstrated the ability to solve or resolve problems relating to the subject matter and work.

rated load

See load, rated.

reeving

A system in which a rope or chain travels around drums, sheaves or sprockets.

roller chain

See chain, roller.

sheave

A grooved wheel or pulley on a hoist that is used with a rope or chain to change direction and point of application of a pulling force.

sheave, nonrunning

A hoist sheave used to equalize tension in opposite parts of the rope or chain. Because of its slight movement, it is not termed a running sheave.

sheave, running

A hoist sheave that rotates as the load block is lifted or lowered.

side pull

The component of the hoist pull acting horizontally when the hoist lines are not operated vertically.

sprocket, idler

A freely rotating device that changes the direction of the hoist load chain.

sprocket, load

A hoist component that transmits motion to the load chain. This hoist component is sometimes called load wheel, load sheave, pocket wheel, or chain wheel.

switch

A device for making, breaking, or changing the connections in an electric or pneumatic circuit (valve).

trolley

A machine unit that travels on a monorail track or crane bridge girder.

trolley hoist

A hoist and trolley unit consisting of a hoist suspended from or mounted to a trolley, or a hoist with an integral trolley.

welded link chain

See chain, welded link.

wheel, hand chain

A wheel with formed pockets on its periphery to allow torque to be transmitted when a force is applied to the hoist hand chain.

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