GB494338A - Improvements in synchromesh gears - Google Patents

Abstract

494,338. Positive clutches. HAWORTH, L. March 19, 1937, No. 8123. [Class 80 (ii)] In synchromesh change-gear mechanism in which the engagement of a pair of friction elements, prior to the engagement of dog elements, produces a rotation of the movable friction element relative to its associated slidable dog element whereby, through cam surfaces, an axial thrust is imparted to the movable friction element so as to press it more firmly against the fixed friction element, the reaction to the axial thrust is transmitted to the gear shaft through cushioning means. A two-part sleeve C, C<1>, shown developed in Fig. 2, and carrying a friction cone at each end, encircles a doubleended dog member B‹ splined on the gear shaft A and is itself encircled by a fork-actuated sleeve D which is connected to the member B<6> by pins D<2> passing through slots D<3> in the adjacent ends of the sleeves C, C<1> these ends being normally drawn together by springs (not shown). In the neutral position shown, spring detents E<4> in the member B<6> engage circumferential grooves E<5> in the sleeves C, C<1>, so as normally to prevent relative axial movement between the members B<6>, C, and C<1>, while spring detents E<6> in the member B<6> engage axial grooves E<7> in the sleeves C, C<1>, so as normally to prevent relative angular movement between the members B<6>, C, and C<1>. The ends of a cross-pin E, which is capable of axial movement in the shaft A in either direction against springs F<1>, pass through slots E<2> in the member B<6> and engage cam slots E<3> in the adjacent ends of the sleeves C, C<1>. If the connected members D, B<6> are moved, say, to the right, for engaging the member B<6> with dogs on a freely-mounted but axiallyfixed pinion B<2>, the sleeve C<1> is carried along by the detents E<4> and is brought into frictional engagement with the gear B<2>. The consequent rotation of sleeve C<1> relative to member B<6> firstly, brings the pins D<2> into. side notches D<4> in the slots D<3> so as to prevent further movement of the member B<6> until synchronism is reached, and, secondly, causes the pin E to coact with the cam slots E<3> so as to impart an additional thrust to the sleeve C', the reaction to this thrust being transmitted to the shaft A through one of the springs F<1>. When synchronism is attained, the member B<6> can be moved into engagement, the sleeve C<1> being retracted by its springs. The detents E<4> then engage other circumferential grooves E<12> in the sleeve C<1> to maintain the dog clutch engaged. Specification 440,126 is referred to. According to the Provisional Specification, the pin E may be secured to the shaft A.