GB458402A - Improvements in or relating to gear-changing means for motor vehicles - Google Patents

Abstract

458,402. Controlling change speed gearing. CLERK, R. C., Sweet Briar, Towing Path, Egham, Surrey. May 18, 1935. No. 12029. [Class 80 (ii)] Gear-changing mechanism having selector bars g, h, Fig. 1, moved oppositely to gear positions from neutral comprises a preselector profile member e, Fig. 6, the changes being effected by the pedal or servo device (not shown) operating the main clutch of a vehicle. To change from the neutral position of Fig. 1 with clutch engaged, the preselector e is first operated, automatically or by hand, to, say, the position of Fig. 2. The clutch pedal is then depressed. This swings a bell-crank lever m from the equilibrium position shown in Fig. 1 to position m<1>. A block j then slides to position j<1>, and two ratchet levers a, bare swung about the same pivot f to come together scissor-wise to the position of Fig. 2. The lever a is shown apart in Fig. 5. Notches a<3>, b4, Fig. 1, come together on a pin c<3>, Fig. 4, on a ratchet lever c, and notches b<3>, a<4> come together on a pin d<3> on a ratchet lever d, so that these levers c, d are necessarily in the neutral position with other parts, as shown in Fig. 2. A selected pawl a<1> then falls through a gap e<1> in the profile member e into position to engage a ratchet tooth c<1>, Fig. 4, on the lever c. On release of the clutch pedal, the bell-crank lever m and the block j fly back to the position of Fig. 1 and the levers a, b are turned downwards of Fig. 3 to the position shown with the selector bar g attached to the pin c<3> in its lower gear position. The lever m after passing the dead centre m<2>, Fig. 1, causes the block j to rise a little so as to ease the last operative pawl a<1> out of engagement with its tooth c<1> so that the pawl does not obstruct the free movement of the preselector on the next change. The bar g is moved up when a pawl b<1> engages a ratchet c<2>, Fig. 4. The bar h moves down or up according as a pawl b<2> engages a ratchet d<2>, or as a pawl a<2> engages a ratchet dl.