GB190605631A - Improvements in or relating to Full-stroke Devices for Calculating Machines or other Mechanism. - Google Patents

Abstract

5631. Postans, A. J. March 8. Levers.-Relates to devices for ensuring the fullstroke of levers &c. As shown in Fig. 1, a lever A, pivoted at A', is formed with two stops C', C' for limiting its stroke. A curved face C, concentric with the pivot A<1>, lies between these stops. A pawl engaging the curved face C permits movement of the lever in one direction only, until at the end of the stroke the stop C<1> rocks the pawl, which is held out of engagement with the face C by a detent, until at the end of the return stroke the stop C' returns the pawl to its operative position. The pawl D shown in Fig. 1 has a point D<2> engaging with the serrated face C. The detent shown is a ball E pressed by a spring into a recess d<1> in the pawl. In a modification, the pawl has a convex face which engages frictionally with the lever. In a second modification, the pawl has two convex faces, so as to form a two-way full-stroke device. In the latter case, no detent is necessary, although the spring is retained to keep the pawl in engagement with the lever. According to the Provisional Specification, the above-described pawl may be replaced by an ordinary pawl-and-ratchet device.