GB718720A - Improvements in towing hooks - Google Patents

Abstract

718,720. Couplings for vehicles. NATIONAL RESEARCH DEVELOPMENT CORPORATION. Sept. 25, 1952 [Sept. 25. 1951]. No. 22364/51. Class 103(5) [Also in Group XXV] Relates to towing hooks in which a frame member carries both a hook and a moving member relatively movable between closed and open positions and in which the movement is controlled by an actuator through a toggle device that is moved just beyond the dead centre when the hook is in the closed position and consists in providing an abutment to limit the movement of the toggle past the dead centre. The hook 2 is pivoted at 4 between the sides la of the frame an is moused by a projection 3 from the frame. Toggle links 5, 6 are pivoted to the frame at 8 and to the hook at 9 and an extension of the link 5 is pivoted to a spring-loaded plunger 13 that biases the toggle into the position shown in which the hook is closed and the toggle has snapped just over the deadcentre position to rest against a shoulder 11 on the hook. The hook is opened by manual actuation of the arm 16b of a cranked lever, the other arm 16a using the shoulder 11 as abutment. A second cranked level is pivoted to.the hook at 18 and projects therefrom at 17b for contact -by a coupling shackle 10 raising the arm 17a to break the toggle and raise the hook permitting the shackle to enter after which the spring recloses the hook and coupling is completed. The arm 17b may also be operated manually to release the load.