GB494411A - Improvements in synchromesh gears - Google Patents

Abstract

494,411. Positive clutches. HAWORTH, L. March 19, 1937, No. 26668/38. Divided out of 494,338. [Class 80 (ii)] In synchromesh change-gear mechanism, the engagement under the control of the gear lever of a pair of friction elements, prior to the engagement of dog elements, produces a rotation of the slidable friction element relative to its associated slidable dog element whereby, through cam surfaces, an axial thrust is imparted to a second slidable friction element so as to press the latter against the fixed friction element, the reaction to this axial thrust being transmitted to the gear shaft. A double-ended fork-actuated dog sleeve G<1> is splined on a collar G of the gear shaft A. Sleeves G4 and G<6> mounted in the sleeve G<1> on either side of the collar G each carry a friction cone, and sleeves G<5> and G<7> mounted within the sleeves G<4> and G<6> and each carrying a friction cone are splined on the shaft A and are urged towards the collar G by a spring K. Rings J<2> and J<3>, interposed between the sleeves G<5> and G<7> and the collar G, have camshaped ends co-operating through interposed balls J<6> and J<7> with the complementary camshaped ends of the sleeves G<5> and G<7> the rings being coupled for rotation with the sleeves G4 and G<6> by pins J and J<1> projecting from the latter into axial slots in the former. The sleeves G<4> and G<6> carry spring rings H and H<1> normally engaging grooves in the sleeve G<1> and are spaced by pins G<8> slidable in the collar G. If the sleeve G<1> is moved, say, to the right, from the neutral position shown, for engaging it with dogs on the freely-mounted but axially-fixed pinion B<2>, the sleeve G<6> is carried along by the spring ring H<1> and is brought into frictional engagement with the gear B<2>. The consequent rotation of sleeve G6 relative to the shaft is imparted to the ring J<1> and, due to the cam surfaces, the sleeve G<7> is thrust into frictional engagement with the gear B<2>. A dash-pot may be provided to control the movement of sleeve G<1>.