A method of control by which the hoist motor is connected in the lower direction, that when it is over-hauled by the load, it acts as a generator and forces current either through the resistor or back into the life.
How does a hoist motor work?
An over-hauling hoist load turns the motor into a generator. The energy generated returns power to the supply line or other type of electrical absorption load. The power losses put an electrical load, or drag, on the crane motor, which is now a generator, and control the lowering speed to a safe value.
What is the purpose of a hoist?
A hoist is a mechanical lifting device that can lift someone from a seated position and transfer them to another location, such as a bed, a seat or a bathtub. Some hoists can move horizontally between areas within a room or between rooms.
How does a crane hoist work?
Manual Overhead Crane Hoists
One chain is used to lift and lower the load and the other chain is used to support the load. The chain is pulled using a hand-over-hand motion, or a handheld lever or ratchet, to turn the gears located inside the hoist and deposit the chain in a chain basket.
What is the hoist on a crane?
A hoist is a machine that performs a single task very well: lifting and lowering a load on a vertical plane (Figure 1, Motion 3). Hoists are situated on the primary horizontal beam of the crane, called the bridge girder.
What type of motor is used in hoist?
While PMDC motors are used in hoist, reel and winch applications up to 10 HP, wound field DC motors 14 are commonly used in industrial applications above this range and up to several hundred horsepower (HP), in both the standard and explosion proof types.
What is the difference between a crane and a hoist?
A Crane is a complex device used for moving loads in various directions. … While a hoist by itself can only raise and lower objects on a vertical plane, it is the component used for that purpose as part of a crane’s wider application. Hoists, as well as cranes, are typically used in a construction or industrial setting.
Can you use a hoist without training?
never use a hoist that they have not been trained to use. always ensure that the right hoist is being used for the job — if in doubt, staff should be trained not to use the hoist but to reassess the handling operation. never exceed the safe working load of the hoist.
Is it legal for one person to use a hoist?
It’s not a legal requirement for two people to hoist a patient, but a few companies and care providers will specify that you should only ever hoist someone when there are two carers to do so. … If it doesn’t, then you can probably hoist the patient by yourself.
What can go wrong when hoisting a person?
Some of the things that can potentially go wrong during a hoisting procedure include: Selection of the wrong size sling – resulting in discomfort if the sling is too small and a risk of the person slipping through the sling if it is too large.
What is chain hoist?
If set up and used correctly, a chain hoist is one of the easiest and most efficient ways of lifting a load. A chain hoist is operated by hand. An operator will pull down on one of the chain loops on one side of the chain. This will turn a pulley mechanism inside the chain hoist housing.
What is the difference between a hoist and a winch?
A winch is designed to pull a heavy load horizontally over a slightly inclined or level surface, and a hoist is designed to lift a load vertically over steeper inclines that are greater than 45 degrees. Both tools can make heavy lifting tasks easier.
What are the types of cranes?
- Telescopic Crane. A telescopic crane offers a boom that has a number of tubes that are fitted inside each other. …
- Mobile Cranes. …
- Truck Mounted Crane. …
- Tower Crane. …
- Rough Terrain Crane. …
- Overhead Crane. …
- Loader Crane.
29 нояб. 2017 г.
What is the end of a crane called?
JIB CRANE – A crane design whereby the bridge girder (commonly called the boom) is fixed at one end, allowing the opposite end to cantilever. The fixed end generally is hinged to allow rotation. LIFT – Maximum safe vertical distance through which the hook, magnet, or bucket can move.
What is hoist lift?
A hoist is a device used for lifting or lowering a load by means of a drum or lift-wheel around which rope or chain wraps. … The most familiar form is an elevator, the car of which is raised and lowered by a hoist mechanism. Most hoists couple to their loads using a lifting hook.
What means hoist?
1 : lift, raise especially : to raise into position by or as if by means of tackle hoist a flag hoist the sails Cargo was hoisted up into the ship.