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US 4,327,533 AGranted
Crane boom extending, retracting and cooperative latching arrangement
AssigneeKidde, Inc.
InventorRussell L. Sterner
Life of this patent
Estimating the term…
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AssigneeKidde, Inc.
InventorRussell L. Sterner
Estimating the term…
To reduce the weight and increase the lifting capacity of a multi-section telescopic crane boom, a single hydraulic cylinder for the full extension and retraction of individual boom sections is anchored in the relatively stationary boom base section. A sled structure surrounding the single cylinder and moving therewith has guided engagement through plates fixed to the movable boom sections at or near their rear ends. Driving finger mechanisms on opposite sides of the sled are biased toward driving engagement with the plates of the movable boom sections and are retractable into chambers of the sled. A cooperative locking pin operating assembly for the movable boom sections is fixed on the forward end of the boom base section and includes power retracting devices which operate mating retracting cranks and locking pin sets individual to the movable boom sections when the retracting cranks are aligned beneath the power retracting devices. The movable boom sections are equipped near their outer and inner ends with locking receivers for said locking pins.
A crane boom comprising plural telescoping boom sections which are individually movable relatively and a boom base section which is relatively stationary and in which all of the movable boom sections may be nested telescopically, each movable boom section having locking detent means thereon near its outer and inner ends, a single power cylinder anchored within the boom base section and being extensible and retractable longitudinally of the boom to fully extend and fully retract selectively any individual movable boom section, each movable boom section having a fixed driving member near its rear end, cooperative driving means for said fixed driving members on said cylinder and moving therewith and being biased toward engagement with the fixed driving members, power means moving with said cylinder to retract said cooperative driving means from said fixed driving members to enable the driving means to pass by certain fixed driving members, a locking assembly common to the movable boom sections and being fixed to the boom base section, plural independently operable locking elements individual to the movable boom sections on certain of the movable boom sections and moving therewith and being biased toward engagement with said locking detent means of adjacent movable boom sections, and plural selectively operable power means on said locking assembly to retract said locking elements of any movable boom section from the locking detent means of an adjacent boom section so that the latter may be fully extended or retracted by said single power cylinder.
In a crane boom, a relatively stationary boom base section and a plurality of relatively movable boom sections which are telescopically nestable in the base section when retracted and extendable therefrom, means to fully extend and fully retract each movable boom section selectively to produce desired boom configurations, a locking mechanism common to all of the movable boom sections fixed on the boom base section near its forward end, movable locking elements carried by certain of the movable boom sections near their forward ends and being biased toward locking positions, with adjacent movable boom sections, the movable boom sections having locking receivers for said locking elements near their forward and rear ends, and power means on said locking mechanism operable to selectively retract the locking elements from their locking positions to enable the full retraction or full extension selectively of the movable boom sections by the first-named means.
A crane boom comprising plural telescoping boom sections which are individually movable relatively and a boom base section which is relatively stationary and in which all of the movable boom sections may nest telescopically, a fixed driving plate on each movable boom section near its rear end and having a guide opening formed therethrough, a single power cylinder anchored within the boom base section and being extensible and retractable longitudinally of the boom to fully extend and fully retract selectively the movable boom sections, cooperative driving means on said single power cylinder and moving therewith and having guided engagement within said guide openings, the cooperative driving means including at least on one side thereof extendable and retractable positive drive elements for said plates biased toward driving engagement therewith, power means on said cooperative driving means to retract said positive drive elements from said plates, and additional selectively operable power means on the boom base section and movable boom sections to releasably lock the latter in fully extended and fully retracted positions.
Dependencies are inferred from the claim text.