Patent GB-460681-A (GB)
Title: Improvements in or relating to dog clutches or disengageable toothed gearing
IPC: F16D11/10
Filed: 1936-03-11
Abstract: 460,681. Positive clutches; toothed gearing. ROWE, A. H. R. March 11, 1936, No. 7343. [Classes 80 (i) and 80 (ii)] In a claw clutch, a claw member 14 splined on a driven (or driving) shaft 11 is urged axially by a spring 27 towards a claw member 13 rotating with the driving (or driven) shaft 10, and a member 29 axially positioned on the shaft 11 is urged angularly relative to the latter by a spring 34 into such a position that pins 32 on the member 29 prevent the axial movement of the member 14. A member 23 rotating with the shaft 10, and carrying a conical-ended pin 24 loaded by a spring 25, is adapted to be moved to the left, by a rod 22, so that the pin 24 engages a conical depression 36 in a block 35, mounted in the member 29, when the members 23, 29 are in a predetermined relationship. The member 29 is thus turned around the shaft 11 until, at a predetermined relative position, the pins 32 engage in holes 33 in the member 14. The latter is now free to move into engagement with the member 13, the arrangement being such that the claws are in register at the moment of engagement. The spring 25 is such that it cannot take the load of the driven shaft, so that the pin 24 rides out of the recess 36 when the pins 32 engage the holes 33. The member 13 moves with the member 23, these two members being secured on a shaft 18 which rotates with but is movable axially relative to the shaft 10. When the clutch engages, the spring 27 returns the shaft 18 to its original position. The clutch is disengaged by moving member 14 to the left by means of a rod 37. The pins 32 may be arranged non-symmetrically as shown, so that the clutch can engage in only one relative position of the clutch members. When the speed of rotation is low, and thus the rotation of the member 13 relative to the member 14 during the axial movement of the latter is insignificant, the block 35 may be secured to or integral with the member 29. At higher speeds, means are provided for moving the block rearwardly relative to the member 29, so that the member 14 is released earlier, by an amount varying with the speed. Thus, the block 35 is secured to a disc 38 rotatable on the member 29 and is acted on by oppositely-arranged springs 40, Fig. 4. A pinion 43, journalled. in the member 29 and integral with an arm 44 overlying the recess 36, meshes with teeth 42 on the plate 38. During the movement of the member 23 to the left, the pin 24 delivers a blow to the arm 44, causing the block 35 to turn rearwardly relative to the member 29, until brought to rest by the springs 40, the extent of this movement being dependent on the speed of rotation. A pair of oppositelyarranged spring-pressed pawls 50 carried 'by the block and co-operating with oppositelyarranged ratchet teeth 48 on a ring 47 secured to the member 29, cause the block to be locked in its new position. Each pawl is connected by a link 53 to a lever 54 connected to a slidable member 56 projecting into the recess 36. Thus, when the pin 24 enters the recess, it presses the members 56 outwardly, thereby withdrawing the pawls from the teeth 48. Prior to this, however, the pin 24 engages a spring-loaded pin 58 and forces it inwards into engagement with teeth on a member 60 secured in the member 29. The block 35 thus remains locked. Each lever 54 has a nose 61, Fig. 3, co-operating with a slidable plate 62 formed with teeth meshing with a pair of gears 63 secured on a shaft 64 biassed by a spring 65. Each gear 63 meshes with an arcuate rack on one end of a lever 66, Fig. 5, carried by the block 35, the other end of the lever -normally engaging a cam projection 68 on the ring 47, so that the plate 62 is held out of the path of the noses 61. As soon as the block moves from its normal position, the levers 66 leave the projections 68 and the spring 65 causes the plate 62 to move into the path of the noses 61. Thus, when the pin 24 engages in the recess 36, the pawls 50 are locked in their disengaged position. When the pin 24 leaves the recess, the pin 58 is released, the block 35 returns to its normal position, the levers 66 re-engage the projections 68, and the pawls are freed. As applied to disengageable toothed gearing, the member 14 is replaced by a gear movable into mesh with a gear on a shaft parallel to the shaft 11. the member 13 is omitted, and the shaft 10 is geared to the parallel shaft with the same gear ratio as the main gears. Specifications 23323/03, 24243*/04, 27819/07, [all in Class 80], 268,545, 298,420, [both in Class 80 (ii)], 440,351, and 442,208 are referred to.