Patent GB-1003025-A (GB)
Title: Improvements in and relating to lifting devices
IPC: B66F3/35
Filed: 1964-01-21
Abstract: 1,003,025. Garage lifts; fluid pressure ratchet jacks. M. CITROEN. Jan. 21, 1964 [Jan. 22, 1963], No. 2690/64. Headings B8H and B8J.  A garage lift comprises platforms 16, 17, each provided with latching devices adapted to engage notches 103 in corner posts 11-14, and jacks mounted between the platforms for raising the platforms step by step up the corner posts. The jacks comprise pneumatic piston and cylinder devices or inflatable tubular bags 26, 27, Fig. 3, and in operation, the bags are inflated until the platform 16 engases stops 38a secured to the platform 17, after which the bags are deflated allowing springs 35 to draw the platforms towards each other. Each latching device on the platform 16 comprises an arm 101, Fig. 14, provided with lugs 114, adapted to engage in the notches 103 in the post 11, and pivoted on a shaft 116 supported by the platform 16. Springs 118, 126 extend between recesses in a lever 119, on the shaft 116 and recesses in respectively the arm 101 and a member secured to the platform 16. The latch devices on the platform 17 each comprise an arm 102 secured to a shaft 131, rotatably mounted on the platform, and provided with lugs 132 adapted to engage the notches 103. A lever 138 mounted on the shaft 131 is connected by springs 142, 137 to the platform 17 and to an arm 135 secured to the arm 102. For a lifting operation, a reversing cam 146 is positioned about a pin 147 on the platform 16 as shown in Fig. 14, wherein the lugs 114, 132 are held resiliently against the post 11. On movement of the platforms 16, 17 towards and away from one another, the lugs 114, 132 move alternately into high notches 103 in the post 11. For downward movement of the platforms 16, 17, the cam 146 is rotated to the position shown in Fig. 16 in which the platforms are at the end of the approach stroke. In this position, the arm 119 is held in its operative position by a stop 150, which is pivotally mounted on the platform 16 and which is held in the position shown by engagement with a stop 112 on the platform 17. The spring 137 is predominant over the spring 142, since the arm 138 is held in the position shown by engagement with the cam 146, and urges the arm 102 outwardly. When the platforms are moved apart, the platform 17 descends, and the arm 138 is pivoted upwardly by the spring 137 and urges the arm 102 against the post 11 so that the lugs 132 engage in the next lower notch 103. After the lugs 132 have engaged in the notch 103, continued separation of the platforms causes the platform 16 and arm 101 to rise. In this position, the stop 150 having pivoted downwardly out of engagement with the arm 119, the spring 126 is now predominant over the spring 118 and pivots the arm 101 outwardly. On subsequent descent of the platform 16, the stop 150 engages the stop 112 and is pivoted upwardly to re-engage the arm 119 so that the arm 101 is again urged towards the column 11 and causes the lugs 114 to engage in the next lower notch 103. Completion of the separation stroke then raises the platform 17 to allow the lugs 132 on the arm 102 to be freed and the cycle is repeated.  As shown in Fig. 20, the platform 16 is replaced by U-section tracks 20, 21 secured to cross-members 22, 23 and the platform 17 is replaced by cross-members 24, 25. The four reversing cams 146 are interconnected and are rotatable by means of a lever 70.