Patent GB-583127-A (GB)
Title: Improvements in or relating to cranes
IPC: B66C23/36
Filed: 1944-05-02
Abstract: 583,127. Cranes. CHUTE FARMS, Ltd., RANSOMES & RAPIER, Ltd., SYKES, F., and BOWTELL, W. J. May 2, 1944, No. 8226. [Classes 78 (iv) and 78 (v)] A crane for general farm duties which either serves as a trailer to a tractor and is driven therefrom, or may have an independent power unit for actuating the crane mechanism and propelling the chassis at slow speed, comprises a chassis frame A, Fig. 1, a pair of wheels B <1>, hollow post C of square cross-section supported from the centre of the frame between the wheels, a jib E carried by a structure which can be slued about the the post by mechanism, mechanism for raising a load comprising a rope which runs from a drum. on the frame through the post to the head of the jib, wheeled means for supporting the end of the frame opposite to that at which is the post, and a source of power by which the load is hoisted and the jib slued. The post C is built up from two angle members welded together. The framing from which projects the jib is mounted rotatably on the post and comprises a toothed wheel D, Fig. 5, having on its upper side a rectangular box-like structure D<1> attached to vertical members D<2>. Transverse members D<3>, which connect the upper ends of the members D<2>, carry a bearing which is rotatable on the end C <5> of the post. Lugs D <5> upstanding from .the members D<3> support sheaves F, F<1> for the hoisting rope. Two parallel arms G, Fig. 1, extend rearwardly from the framing D<2>, D3 and are supported by struts G<1>. The arms carry an adjustable balance weight G<2> and are provided with a series of anchorages for the ropes E<2> which support the head of the jib. Each anchorage comprises a pair of hooks G3 which receive a bar E<3> connecting the ends of the rope. The heel of the jib members E is pivotally supported in lugs D<4> formed on the structure D<1> by a pin E<1>. A main transmission shaft H mounted on the lower parts of the chassis frame is connected by flexible shafting J<1>, Fig. 1, to the engine of a tractor J. Two pairs of bevel pinions K, K<1> and L, L<1>, Fig. 4, are free on the shaft H and mesh, respectively, with bevel wheels M, N on shafts M<1>, N<1>. The shaft M<1> is connected by gears M<2>, Q<2> to a shaft Q<1> carrying the drum Q<2> for the hoisting rope R. The shaft N<1> is connected by worm gearing N<2>, P to a vertical shaft P<1> carrying a pinion P<1> which meshes with the toothed wheel D. Clutches K2, K<3> and L<2>, L3 enable the pinions K, K<1> and L, L<1> to be coupled alternatively to the shaft H. Self-sustaining brake mechanism of the pawl-and-ratchet type may be mounted on the shaft M<1>. In order that the position of the connecting device on the shaft H can be changed to suit the vertical or lateral position of the tractor, and also to vary the speed of the shaft, a pinion H<1>, Fig. 15, is secured to the shaft H through an overload slip device H<2> and meshes with a pinion H<3> on a stub shaft H<4>. This stub shaft is mounted in a frame H <5> which can be turned about the axis of the shaft H and locked in any position by bolts H<6>, Fig. 16, engaged with any two of a series of apertures H<7>.