Overload indicator for hoist
AssigneeJPW Industries Inc.
InventorsSteven Myers, Charles Weber
Life of this patent
Estimating the term…
Abstract
An overload indicator for a hoist includes first and second blocks that connect to the lifting medium (a chain for a chain hoist) at spaced locations. The first and second blocks are held at a spacing by indicator bands so that the lifting medium is slack between the blocks. The indicator bands have weakened portions to deform, stretch or break when subject to a load over a threshold, such as over a lifting capacity of the hoist. Covers are provided over the indicator bands that are closely spaced to define an indicator gap. If the indicator bands stretch, the indicator gap increases to indicate an overload condition.
Claims17
An overload indicator for a hoist, the hoist having a lifting medium for lifting a load, comprising:
- first and second block portions connected to the lifting medium as spaced locations from one another, the spaced locations being such that the lifting medium is in a slack condition between the first and second block portions when the overload indicator is in a non-indicating position;
- an indicator band connected between the first and second block portions, the indicator band supporting substantially all of the load applied to the lifting medium when the overload indicator is in the non-indicating position, the indicator band being configured to at least one of stretch and deform and break upon application of a load greater than a predetermined threshold.
A method for indicating that an overload condition has been applied to a hoist, comprising:
- attaching first and second blocks to a lifting medium of the hoist at first and second locations spaced from one another with a length of the lifting medium between the first and second blocks;
- attaching first and second indicator bands to the first and second blocks, the first and second indicator bands being generally parallel to one another and generally parallel to the length of the lifting medium between the first and second blocks, the indicator bands being configured to stretch or deform when subjected to a tension over a predetermined threshold;
- attaching covers over the indicator bands, the covers defining an indicator gap, wherein the indicator gap is a first gap distance when the indicator bands are in their un-stretched or un-deformed state and the indicator gap is at a second gap distance after the overload indicator has been used to lift a load greater than the predetermined threshold.
Dependencies are inferred from the claim text.