GB408646A - Improvements in or relating to lifting jacks - Google Patents

Abstract

408,646. Lifting-jacks. LAKE & ELLIOT, Ltd., Albion Works, Braintree, and RUBURY, J. M., Little East, Bocking, both in Essex. Oct. 12, 1932, No. 28490. [Class 78 (iii).] In a jack of low initial height the crutch is carried on a lever or pair of levers 50 pivoted at 49 on a pair of levers 48 which are pivoted at 45 on the frame 44, and the lever 50 is operated by a lever 54 pivoted on the frame at 55 and connected with the lever 50 at 53 so that initial movement of the operating lever from the position shown causes only a slight movement of the fulcrum 49 due to the lowering of the point 53 but further movement displaces the lever 50 forwardly swinging the fulcrum 49 about the pivot 45. The crutch moves substantially in a vertical line. As shown in Fig. 2 the jack is provided with wheels 46 at the forward end and the levers 48 are pivoted upon the axle. The crutch is retained in the raised position by a pawl 63 on the operating lever engaging teeth 65 on the frame. The rear end of the frame is connected to a U-shaped block 47 forming a support. As shown in Fig. 4, the levers 50 are actuated through reversible ratchet mechanism. The levers 50 are pivoted to crank pins 66 on a ratchet wheel 67 on the base 47. A lifting pawl 69 is pivoted on the operating lever 54, and a holding pawl 70 is pivoted on the base. The pawls are held in lifting position, Fig. 6, or lowering position Fig. 4, by a flat spring 74, according to the setting of a cam 76 on a pedal lever 75.