GB1296374A - - Google Patents

Abstract

1296374 Clutches SSS PATENTS Ltd 19 Feb 1970 [3 March 1969] 11191/69 Heading F2C Engagement of a synchronous self-shifting clutch comprising a driving member 11, a driven member 19 and a helically movable intermediate member 14 is initiated by the usual pawl and ratchet 17, 22, and the clutch is arranged in parallel with a similar clutch comprising a driving member 25, a driven member 28 and an intermediate member 32, but without the pawl and ratchet, the clutches being arranged so that movement of the first intermediate member 14 to effect partial clutch engagement is transmitted with lost motion to the second intermediate member 32 to effect partial engagement of the second clutch the lost motion allowing the subsequent self-shifting action of the clutches to be made independently. The clutches are used to clutch gear-wheels (6), (6<SP>1</SP>), Fig. 1 (not shown), on shaft sleeves (5), (5<SP>1</SP>), to respective lay shafts (4), (4<SP>1</SP>) between a single input shaft (1) and output shaft (8), to ensure simultaneous clutch engagement and equal load sharing by the lay shafts. As shown, the intermediate members are interconnected by a pivoted lever having arms 39, 40 of unequal length and engaging in grooves 37, 43 in the members. The arm 39 engages with lost motion in groove 37 so that initial movement of member 14 due to the engagement of the pawl and ratchet 17, 22, and then to the transfer teeth 16, 23, has no effect on the intermediate member 32 until the lost motion is taken up, when both intermediate members 14, 32 move to partially engage their respective teeth 15, 21 and 33, 27. On such engagement, the difference in length of the lever arms 39, 40 allows the member 14 to move more slowly than the member 32 to full engagement, re-establishing the lost motion and relieving the lever 39, 40 and hence member 14 of the load of member 32. The transfer teeth 16, 23 may be inclined or plane co-operating faces, Figs. 3A and 4 (not shown). Again, Figs. 5A, 5B (not shown), the transfer teeth are omitted and the teeth 21 made longer than teeth 15, teeth 27, 33 having co-operating chamfered edges. In an alternative embodiment, the lead of the helical splines of the second clutch is greater than that of the first clutch, the lever arms 39, 40 being of equal length, or the lever being omitted and the clutches arranged coaxially so that the intermediate members directly abut.