Luffing jib backstop assembly
AssigneeThe Manitowoc Company, Inc.
InventorsTerry Casavant, Michael Wanek
Life of this patent
Estimating the term…
Abstract
A luffing jib backstop assembly for limiting rotation between a luffing jib and a boom to which the luffing jib is attached is disclosed. The assembly comprises at least one backstop pendant attached at a first end to the luffing jib and at a second end to the boom, the pendant having a length sufficient to allow the luffing jib to be extended to an angle of 180.degree. with respect to the boom. The assembly further comprises a deployable member which engages the backstop pendant and which, upon full deployment, holds a portion of the backstop pendant away from the boom and luffing jib such that the pendant and deployable member prevent the luffing jib from rotating with respect to the boom beyond a permissible operating angle.
Claims19
A luffing jib backstop assembly for limiting rotation between a luffing jib and a boom to which the luffing jib is attached, the assembly comprising:
- (a) at least one backstop pendant attached at a first end to the luffing jib and at a second end to the boom, the pendant having a length sufficient to allow the luffing jib to be extended to an angle of 180.degree. with respect to the boom;
- (b) a deployable member which engages the attached backstop pendant and which, prior to deployment, permits the luffing jib to be extended to an angle of 180.degree. with respect to the boom and which, upon full deployment, holds a portion of the attache backstop pendant away from the boom and luffing jib such that the pendant and deployable member prevent the luffing jib from rotating with respect to the boom beyond a permissible operating angle which is less than 180.degree..
A luffing jib backstop assembly for limiting rotation between a crane luffing jib with respect to a crane boom, the assembly comprising:
- (a) at least one backstop pendant, comprising two wire ropes, a first end of a first wire rope attached to the boom and a second end of the second wire rope attached to the luffing jib;
- (b) a telescopic strut which is attached at a first end to the crane adjacent the point at which the luffing jib and the boom pivot with respect to one another and to which is attached at a second end of the strut a second end of the first wire rope and a first end of the second wire rope;
- and
- (c) a latch for fixing the telescopic strut in an extended position.
A crane comprising:
- a) a boom;
- b) a luffing jib pivotally attached to the boom;
- c) a pair of backstop pendants each comprising a first and second wire rope, a first end of each first wire rope attached to the boom and a second end of each second wire rope attached to the luffing jib;
- d) a deployable member which is attached at a first end to the crane adjacent the point at which the luffing jib and the boom pivot with respect to one another and to which is attached at a second end of the member a second end of each first wire rope and first end of each second wire rope;
- and
- e) a retractable member for fixing the deployable member in an extended position;
- whereby as the boom is raised and the luffing jib pivoted with respect to the boom, the deployable member extends outwardly from the boom and is fixed in an extended position to effectively limit the operating angle of the luffing jib with respect to the boom.
Dependencies are inferred from the claim text.