GB610259A - Improvements in or relating to mobile jacks - Google Patents

Abstract

610,259. Lifting-jacks. LAYCOCK ENGINEERING CO., Ltd., and CHARLESWORTH T. R. April 3, 1946, No. 10262. [Class 78 (iii)] In mobile hydraulic jacks of the type in which the two ends of a common control lever pivoted to the operating handle serve respectively to push or pull a rod by which either locking of the handle or lowering of the load are correspondingly effected, the risk of accidental lowering is minimized by mounting a sleeve on the handle which must be turned to free the control lever. The jack is carried by a wheeled base 10, Fig. 1, and comprises a load-engaging crutch 12 carried at the end of a lever 15 which is raised by movement of a fluid-pressure operated cylinder 21. At the free end of the operating handle 28, a control lever 65, Fig. 5, is pivotally attached at 62 to the wall of the operating handle, the arm 72 of the control lever being received by a slot 63. Coupled to the lever within the handle is a control rod 56 providing connection to the lowering and handle-locking mechanisms. Rotatably mounted on the handle between the control lever and a T-bar 60 is a sleeve 68, provided with a slot 70, the control lever being freed for movement into the lowering position to exert a pull on the control rod when the slots 70 and 63 are in alignment, and freed for movement into the handle locked position to push the control rod when the slot 70 and pivot 62 are in alignment. The slot 70 is sufficiently wide so that after the side 73 of the lever has entered the slot the sleeve can be further rotated to bring a projection 76, Fig. 8, into abutment with the side 72 of the control lever to prevent its accidental return from the handle locked position. A ball-catch 74, Fig. 5, locates the sleeve in its various positions.