US 5,078,364 AGranted

Carriage lock mechanism for portable cable hoist

AssigneeSumner Manufacturing Co., Inc.

InventorJerry J. Harrell

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Abstract

A portable plural telescoping mast cable hoist mechanism is provided which incorporates a single cable for telescopically extending and retracting the mast sections and for controlling movement of a load handling carriage. A carriage lock mechanism is provided to prevent inadvertent movement of the carriage and movable mast sections while the cable hoist mechanism is being transported or otherwise moved about while positioned on its side. The carriage lock mechanism incorporates a freely pivotal carriage lock having a hook at its lower end which is normally positioned out of locking engagement with a locking pin and which is pivoted by gravity into locking engagement with the locking pin while the unit is lying on its side for transportation and handling, thereby securing the carriage and mast sections against inadvertent movement.

Claims16

Dependent claims

A portable cable hoist mechanism having a carriage lock, comprising:

(a) a base structure having base support wheels and side support wheels;
(b) a mast projecting upwardly from aid base structure and having a base section being fixed to said base structure and having a plurality of movable mast sections disposed in telescoping relation and forming an upper end of said mast, said mast further having a load supporting carriage disposed in movable guided relation thereon, said portable cable hoist mechanism being selectively positionable at an upright position supported by said base support wheels of said base structure and being positionable at a side position supported by said said side support wheels;
(c) a winch and cable assembly for imparting telescoping extension and construction of said mast and for controlling movement of said load supporting carriage relative to said mast;
(d) a locking element being disposed in immovable relation with said mast;
and
(e) a hoist position responsive carriage lock being movably supported by said carriage and being automatically positionable at a first position out of latching engagement with sad locking element to permit unrestrained movement of said load supporting carriage in a direction toward said upper end of said mast when said portable cable hoist mechanism is at said upright position and supported by said base support wheels and being automatically positionable at a second position in latching engagement with said locking element to prevent movement of said load supporting carriage in a direction toward said upper end of said mast when said portable cable hoist mechanism is at said side position supported by said side support wheels.

3 more elements

A portable cable hoist mechanism having a carriage lock, comprising:

(a) a base structure having wheels for mobile support thereof;
(b) a mast structure having a bottom mast section fixed to said base structure and extending upwardly from said base structure and a plurality of movable mast sections disposed in telescoping relation;
(c) a carriage housing being fixed to the upper end o the uppermost one of said movable mast sections;
(d) a load supporting carriage being movably supported by said mast structure and being receivable in nested relation with said carriage housing;
(e) a winch being fixed to said bottom mast section and having cable engaging pulleys on said mast sections and said carriage and being operable for controlling telescoping movement of said movable mast sections and movement of said carriage;
(f) side wheel means for supporting said portable cable hoist mechanism when said cable hoist mechanism is positioned on one side thereof for support by said side wheel means;
(g) a locking element being provided on aid mast structure;
and
(h) a carriage lock being movably supported by said carriage and being out of locking engagement with said locking element when said portable cable hoist is upright and being positioned in locking engagement with said locking element responsive to positioning of said cable hoist for support by said side wheel means to thus prevent carriage movement toward said carriage housing and to prevent telescoping extension of said movable mast sections.

6 more elements

Dependencies are inferred from the claim text.