GB734697A - Improvements in appliances for lifting and lowering draught members of trailers or the like - Google Patents

Abstract

734.697. Jacks for supporting trailer draught members. WARREN. R. S. [Nov. 11, 1953 [Nov- 11, 1952], No. 28379/52. Class 78 (3). A trailer jack comprises a standard 1 slidably mounted in a tubular guide 4 mounted on the trailer draw-bar, and screw-and-nut means mounted on the standard for raising and lowering the guide 4, the nut of said means being engageable from the guide 4 at will. The standard is constructed from channel and angle section bars 8, 9 and, at its upper end supports a screw 3 which engages a nut 13 secured at the upper end of a lubricant containing cylinder 14. Lugs 15, 16 secured to this cylinder are arranged to be moved into and out of alignment with a bar 23, secured to the tubular guide 4, on initial rotation of the screw by a handle 12. To facilitate movement of the jack to a stowed position the guide 4 is rotatably mounted at 24 on a plate 5 which is secured to the draw-bar 7 and a releasable bolt 30 is provided in bar 23 to engage a member 26 secured to the draw-bar and so lock the jack in its vertical position. A plate 29 also secured to bar 23 and engaging a member 27 normally prevents pivotal movement of the jack in the reverse direction, but is adapted to buckle in the event of excessive force being applied to the jack, e.g. by towing the trailer with the jack down, thereby saving the jack from damage. A further bolt 35 is provided to lock the standard and guide together at any position of adjustment. In operation, with the lugs 15, 16 turned anti-clockwise as viewed in Fig. 6, the standard is pivoted to a vertical position and allowed to slide freely through the guide into a position in which the foot 2 engages the ground, and the bolt 30 is moved into an operative position. The handle 12 is then rotated so moving the lugs outwardly into the position shown whereafter further rotation of handle 12 moves the lug 15 or 16 which is nearest the bar 23 into engagement therewith and so effects raising of the draw-bar. Where a long lift is required, e.g. when raising the drawbar from the ground, the lugs are each used in turn and bolt 35 is operated to lock the standard to the guide during the change-over from one lug to the other. Load-handling machines.-According to the arrangement described in the Provisional Specification only, the standard is provided, at its upper end, with a winch connected by a cable with the guide 4 and the two members are locked together by a pin engaging a series of aligned holes in said members.