GB243997A - Ratchet jack - Google Patents

Abstract

243,997. Percival, S., (Duff Manufacturing Co.). June 2, 1925. Jacks.-A double acting ratchet jack of the kind having long and short pawls has the trip lever pivoted on the frame and the lowering block held in either of its set positions by a spring. The operating handle engages in a socket 4 mounted on a spindle 5 and carrying the pivoted long and short pawls 7, 6, adapted to engage the lifting rack 2 in the usual way. The lowering block 15 is mounted on a pivot 16 on the frame and has cam projections 13, 14 adapted to co-operate with projections 10, 12 on the respective pawls. The block 15 has a grooved end 18 adapted to be engaged by a spring 19, which in the operative position of the block yieldingly presses the cams of the block against the projections 10, 12 of the pawls and causes their alternate disengagement from the rack. By means of a handle adapted to engage a projection 24, the block can be moved downwards into its inoperative position and is held therein by the curved end 23 of the spring. The trip lever 26 has a pivot 27 engaging a curved slot. 28 in the frame and normally rests against the short pawl. By means of a knob 29 the trip lever can be moved so that the pivot 27 enters the part 32, Fig. 5, of the slot. The notched end 30 of the trip lever then engages the end of the short pawl on its next upward movement, so causing it to move away from the rack carrying with it the long pawl 7 and allowing the rack to fall.