Patent GB-602607-A (GB)
Title: Improvements in or relating to hand lever control means for change speed gears
IPC: B62M25/00
Filed: 1945-07-02
Abstract: 602,607. Locking hand levers adjustable shaft couplings. POULAIN, L. G. July 2, 1945, No. 16837. Convention date, March 30, 1944. [A Specification was laid open to inspection under Sect. 91. of the Acts, July 2, 1945.] [Classes 80 (ii) and 80 (iii)] A hand lever control for bicycle change-speed gears of the shifting chain type, which to ensure correct action should be taken momentarily beyond their new setting when changing gear, comprises a lever coacting with a fixed notched quadrant in such a manner that during movement of the lever in either direction to produce a change of speed the lever passes freely over any notch it meets without engaging therein, whilst a subsequent return movement automatically engages the lever with the first notch it encounters. As shown, the lever 6, Figs. 1 and 2, rotates with a casing 5 integral with a pin 4 freely mounted in the fixed quadrant 1, and may be depressed radially inward with respect to the pin 4 against a spring 31. The lever 6 carries a pin 33 and a pivoted pawl 35 which, when the lever is in its radially outward position and the pawl is midway between two stops 38, 38a on the lever, are in axial alignment and engage simultaneously one of the notches 20a ... 20c in the quadrant 1 to lock the lever therein. To change speed, the lever is fully depressed, when the pin 33 just clears the notch and the lever can be rotated in the desired direction. The pawl 35, which projects radially outwards farther than the pin is, however, retained in the notch until it has been pivoted against one of the stops 38, 38a so that it lags behind the pin and prevents the lever from rising when the pin comes opposite any further notches, as shown in Fig. 4. However, once the lever has passed beyond any notch sufficiently to engage the end of the pawl therein under the action of a centralizing torsion spring 37, reverse movement of the lever causes the pawl to pivot back into its central position and the lever rises when the pin reaches the notch. The lever 6 is connected to the control cable (not shown) of the change-speed gear by a circumferentially adjustable coupling comprising a tangent screw 25 axially located but freely rotatable in the casing 5 and meshing a gear 23 carrying the end of the cable. The Specification as open to inspection under Sect. 91 describes also locking hand levers of various kinds. In one form, a part of the lever itself hinges at right angles to engage notches in a stationary quadrant, the notches being chamfered at one side to facilitate entry even when the lever is slightly displaced beyond the notch on that side. In Fig. 6 (Cancelled), a member 14 slidable but non-rotatable on a central pin 13 coacts through helical splines with a handle 18 rotatable on the main lever 6 and carries a pin 15 projecting through a slot in the lever and engageable with notches 20 on a fixed quadrant 1 when the handle 18 is rotated. The pin 15 may have a rounded end to facilitate entry into the notches if the lever is slightly out of alignment therewith in either direction. A cable adjusting tangent screw 25 may be provided. In Fig. 14 (Cancelled), interengaging cam surfaces 40 on the main lever 6a and a rotary extension handle 6b held in contact therewith by a spring 42 cause a round-ended pin 46 integral with the handle 6b to slide into and out of engagement with notches 20 in a fixed quadrant 1 upon rotation of the handle. A tangent screw 26 may be provided as before. This subject-matter does not appear in the Specification as accepted.