Patent GB-723771-A (GB)
Title: Improvements relating to load handling apparatus for vehicles
IPC: E02F3/352
Filed: 1952-07-25
Abstract: 723,771. Load-handling machines; mobile jib cranes. SMITH, W. H. July 25, 1952 [May 23, 1951], No: 12022/51. Classes 78 (3) and 78 (4). A vehicle mounted load-handling apparatus comprises an inclined track extending longitudinally over the vehicle, a trolley adapted to run along the track, a load-carrying receptacle mounted on the trolley, driving means for moving the trolley along the track and tending to cause the receptacle to move into a dumping position, restraining means for limiting or preventing this while the trolley is moving to the top of the track, and means for rendering the restraining means inoperative when the trolley reaches the top of the track. In the arrangement shown in Figs. I, 6 a pair of channel-section rails 13 are mounted on a tractor 10 and guide rollers 17, 18, 22 are mounted on the trolley which consists of pairs of toggle links 19, 20 pivoted together on the axle 21 of rollers 22, the bucket 11 being pivoted at 24 on an extension 23 of link 20. Concentric with rollers 17, 18 are pairs of pulleys 26, 27 around which passes a hoisting cable 14, the ends of which are anchored to a winch 15 and to the bucket at 28; and bearing on the falls of the cable between pulleys 26, 27 is a roller, not shown, on the axle 21. In operation, with the bucket filled in the full line position shown in Fig. 1, initial winding of winch 15 pivots'the bucket 11 rearwardly about axis 24 to provide a break-away action, whereafter further winding moves the bucket up the rails 13. During this movement the upper flanges of the rails engage rollers 22 and prevent the toggle breaking, but, when the trolley reaches the upper position shown in Fig. 6, gaps 36 in the upper flanges permit the rollers 22 to rise under the action of the falls of the cable 14 bearing on the roller on axle 21, and also by the engagement of rollers 39 with cams 38 welded to the outer surfaces of the rails. After the toggle has been broken the rollers 18 engage stops 35 and subsequent winding causes the rollers 17 to move towards the rollers 18, so effecting tipping of the bucket. Cams 41 are provided to guide the return movement of the rollers 22 to a position beneath the upper flanges of the track rails when the cable is paid out to effect lowering, but in the event of faulty operation of this device the bucket is retained at its upper position by the engagement of a hook 43 with a roller 37. In a modification (Fig. 8, not shown), the rollers on axle 21 are dispensed with and the toggle is retained in its straight position by a spring-loaded latch which is released by the engagement of a roller thereon with a cam track located at the top of the guide rails ; a spring being provided to urge the toggle into a broken position. A pair of hoisting cables are used in this embodiment but, in a modification thereof (Fig. 10, not shown) a single cable and equalizing pulleys are used. Any of the bucket assemblies described may, according to a further modification (Fig. 11, not shown), be incorporated in a detachable unit comprising the guide rails, the trolley and bucket unit, the cable guide pulleys and a winch which is provided with couplings for connection to a tractor power take-off shaft. According to other modifications (not shown) the bucket may be replaced by a manure or hay fork or other type of loading bucket or platform; the guide rails may be extended behind the tractor and provided with a pulley to convert the apparatus into a crane, or the apparatus may be adapted for use with a high-lift hay stacker carried by a pair of long booms pivoted at their rear ends on columns mounted at the rear of the tractor, the movable trolley engaging the under sides of the booms so as to raise them as the trolley is drawn up the rails.