Patent GB-711201-A (GB)
Title: Improvements in and relating to friction synchronised positive clutches
IPC: F16D23/06
Filed: 1948-05-08
Abstract: 711,201. Change speed gearing; positive clutches. FOWLER & CO. (LEEDS), Ltd., J., and HAIST, H. May 8, 1948, No. 12690/48. Class 80 (2) The balking male friction element of a synchromesh positive clutch is co - axially mounted directly on the power-transmitting shaft of a driving or driven clutch member and is free to slide thereon untramelled by auxiliary biasing or friction means, between a position where it frictionally engages a female portion of a driven or driving clutch member and a disengaged position where it is prevented, by contact with an axially fixed abutment formed on or fast with the shaft, from exceeding a predetermined running clearance with the female portion. As shown, a coned balking ring 1, Fig. 8, slidably splined with circumferential play on a shaft 3, co-acts with an internal coned surface 15 in a gear 16 rotatably mounted on the shaft 3 and having involute clutch teeth 16x positively engageable by complementary teeth 10x on a member 10 also slidably splined on the shaft 3. The ring 1 has wide involute teeth 6 engageable with gapped sections 11 of the teeth 10x when the ring ds situated centrally of its circumferential play. The teeth 6 and sections 11 have bevelled edges 8, Fig. 11, which co-act as shown to balk advance of the member 10 while relative rotation exists between it and the gear 16, the camming action of the bevels acting to increase the thrust between the coned surfaces. Abutment shoulders 13 on the shaft splines prevent the ring 1 following the member 10 completely on clutch disengagement and maintain the coned surfaces in sufficiently close relationship for there to be constant drag between them due to an interposed oil film. Such drag assists the normal initial balking movement of the ring due to its inertia, and may be augmented by the provision of oil-retaining grooves 19 on the coned surfaces. The grooves 19 may be formed in continuous wear rings, as of metal or fabric, secured or bonded to the coned surfaces, or may be provided by the clearances between similar but segmental wear facings. The wear rings may be dispensed with and plain coned surfaces of like or unlike material used. In Fig. 1 (not shown), in which the teeth 10x engage the actual gear teeth of the gear 16, the teeth 6 are replaced by axial rectangular tongues with bevelled corners coacting with suitably-shaped recesses in the body of the member 10 adjacent the shaft 3, the tongue ends co-acting with the spline shoulders 13. In a three-speed gear comprising three constant-mesh gear pairs 10 and 10x, 22 and 25, 23 and 26, Fig. 15, between driving and driven shafts 3, 24 respectively, the gear lOx slidably splined on the shaft 24 may engage the gears 25, 26 through clutches like that of Fig. 8, and one, 23, of the gears 22, 23 both fast on the shaft 3 may be engaged with the gear 10 by a clutch like that of Fig. 8 except that it comprises a balking ring 1 rotatably and slidably free on the shaft 3 and having a sleeve 21, on which the gear 10 rotates and is operatively slid and which co-acts with the gear 22 acting in the manner of the invention as an axially fixed abutment.