Patent GB-654701-A (GB)
Title: Synchronising claw coupling device
IPC: F16D23/06
Filed: 1948-05-31
Abstract: 654,701. Positive clutches. GANZ & CO., Ltd. May 31, 1948, No. 14705. Convention date, May 31, 1947. [Class 80(ii)] Comprises several forms of two-stage balkmeans for a frictionally synchronized positive clutch to ensure that positive engagement can occur only during acceleration of the driving member, synchronization by deceleration serving only to release the first-stage balk, acceleration being subsequently necessary to release the second stage. In Figs. 1 and 2 a toothed' clutch-member 2, slidably splined on a driving shaft 1 for positive engagement with teeth 4 in a driven wheel 3, has fixed to it one or more sliding keys 6 each of which has a balkstop 8 coacting with a suitably shaped aperture in a member 9 splined with limited circumferential freedom on the driving shaft 1 and connected with the driven wheel 3 by the interleaved discs of a friction clutch 12. A combined compression and torsion spring 22 urges the inner friction-clutch member 9 axially to the right and circumferentially in the reverse direction of rotation, arrow 25, Fig. 2. Initially, with the driving shaft 1 running forwards (arrow 26), faster than the driven wheel 3, movement of the positive clutch-member 2 to the left, Fig. 1, towards engagement, is balked at a first stage by abutment of the balk-stop 8 on the face of the friction-member 9. the pressure on which engages the friction clutch 12. Deceleration of the driving shaft 1 beyond synchronism causes the driven wheel 3 to drag the friction-member 9 relatively forwards (arrow 26), against the torsion of the spring 22, so that the balk-stop 8 moves off the face and into an aperture 27 in the friction-member 9 where it remains balked in the second stage by a stop-face 28, until acceleration of the driving shaft 1 beyond synchronism causes the friction-member to lag behind (arrow 25), permitting the balk-stop 8 to move off the face 28 and completely freeing the leftward engaging movement of the positive clutch-member 2. During movement of the balk-stop 8 from its firstto its second-stage position, the temporary relief of axial loading pressure on the friction clutch 12 might be sufficient to permit the torsion-spring 22 to turn the member 9 relatively backwards (arrow 25), so that the balk-stop 8 could miss the second-stage balk-face 28 and permit direct positive engagement, and to prevent such action, the left end 31 of the balk-key 6 engages and locks a lost-motion abutment-washer 33 through which the spring 22 bears and acts torsionally on the friction-member 9, thus preventing the torsional action of the spring 22 after first-stage balking. In Figs. 7 and 8, the two-stage balk is obtained by two relatively-rotatable first- and secondstage notched members 74, 73, having a projection-and-slot lost-motion connection 52, 53 biassed by a torsion-spring 64 into the position shown in Fig. 8. One member, 73, has a radial tooth 75 engaging with lost-motion an axial groove 81 in the driven wheel 43, and is the outer member of a friction cone-clutch, the inner member 72 of which is fast on the driving shaft 40. One or more balk-fingers 77 is or are secured to a plate 76, splined without lostmotion in the driven wheel 43 and mounted for free relative rotation only on the positive clutch-member 41, which is slidably splined on the driving shaft 40 and engageable with teeth in the driven wheel 43. A combined compression and torsion spring 80 maintains the friction clutch initially disengaged, and the radial tooth 75 of its outer member 73 in circumferential abutment on the leading face of the groove 81 in the driven wheel 43 as shown in Fig. 8, which assumes forward clockwise rotation. With the driving shaft 40 initially running faster than the driven wheel 43, engaging movement of the driving positive clutch member 41 to the left. Fig. 7, causes the balk-finger 77 to abut against and apply pressure to the face of the first-stage balk-disc 74, thus engaging the friction clutch. Deceleration of the driver 40 beyond synchronism causes the outer friction member 73 to be turned relatively backwards (anti-clockwise, Fig. 8), until its tooth 75 abuts the trailing face of the driven-wheel groove 81, taking with it through the projection 52, the first-stage balk-disc 74, so that a release-notch 78 in the latter registers with and permits axial passage of the balk-finger 77 which then becomes balked in its second stage by abutment on the friction member 73, and at the same time locks the first-stage balk disc 74 for rotation with the driven wheel 43. When now the driver 40'is accelerated to synchronism, the friction member 73 alone can move relatively forwards to the Fig. 8 position, leaving behind the firststage balk-drive 74, in opposition to the connecting torsion-spring 64 and as limited by the projection-and-slot 52, 53, whereupon the release-notch 78 in the first-stage balk-disc 74 registers with a release-notch 79 in the friction member 73, permitting free passage of the balk-finger 77 and engagement of the positive clutch member 41. Figs. 4 to 6 (not shown), are generally similar to Fig. 7, but have the balk-fingers associated with the driving member and use a multi-disc clutch as in Fig. 1. Figs. 11 and 12 (not shown), modify Fig. 7 by fixing the inner toothed clutch member 42 on the driving shaft and sliding the outer toothed member in the splines of the driven wheel. Fig. 13 (not shown), is similar but has an apertured outer friction member as the first-stage balk and an apertured disc behind it for the second, and relative circumferential movement is between the balk-finger and the driven wheel instead of between the friction member 73 and driven wheel as in Fig. 7. Fig. 14 (not shown), is similar to this last form, but has the balk-finger on the outer friction member 73 and the two-stage apertured discs on the driven wheel 43, Fig. 15 (not shown), being similar but having the two-stage balk-discs associated with the driving shaft. To permit easy positive engagement after the release of the second-stage balk, the positive teeth may be helically inclined, Fig. 16 (not shown), and or have clearance, Fig. 17 (not shown), the values being based on the change in forward velocity component which may occur during the final axial engaging movement.