Safety arrangement for a hoist
OwnerJames Zaguroli, Jr.inventor
Life of this patent
Estimating the term…
Abstract
A hoist security arrangement for avoiding dropping of the load when the chain or cable breaks includes a longer redundant auxiliary chain or cable disposed alongside the main chain or cable and which is raised and lowered synchronously with the slightly shorter main chain or cable so that the main chain or cable normally supports the entire weight of the load. If the main chain or cable breaks, the load drops slightly until the slack in the redundant auxiliary chain or cable is eliminated to hold the load solely by tensioning the auxiliary chain or cable. The extent of slack is set to insure that slight lengthening of the main chain as caused by wear does not result in loading of the auxiliary chain or cable.
Claims9
A hoist security arrangement for a hoist having a wrappable main lift element raised or lowered by rotation of a drive member around which said main lift element is at least partially wrapped to lift a load attached to said element, said security arrangement including the addition of a security wrappable lift element also at least partially wrapped around said drive member and extending alongside said main lift element and raised or lowered therewith, and also attached to said load but of a slightly longer length than said shorter main lift element extending between said drive member and said load to remain slack and so as to not be tensioned by the weight of said load unless said main lift element breaks, in which case said security lift element thereafter immediately begins to support said load after said slack is eliminated by the weight of said load.
A method of preventing dropping of a load held by a main load carrying wrappable lift element in a hoist upon breakage of said main load carrying wrappable lift element, comprising installing a security wrappable lift element alongside said main load carrying wrappable lift element of a sufficiently longer length than said main load carrying wrappable lift element so as to avoid tensioning said security wrappable lift element by the weight of said load, said load connected to both said main and security wrappable lift elements, wherein both of said main load carrying wrappable lift element and said security wrappable lift element are at least partially wrapped around a single drive member, said main load carrying wrappable lift element being slightly shorter than said security wrappable lift element so that a slight slack is created in said security wrappable lift element whereby if said main wrappable lift element breaks, said security wrappable lift element thereafter immediately begins to support the entire weight of said load as soon as said slight slack is eliminated by the weight of said load.
Dependencies are inferred from the claim text.