GB609389A - Improvements in or relating to clutches for conveying rotary motion - Google Patents

Abstract

609,389. Positive clutches; change-speed gear. BROCKHOUSE ENGINEERING (SOUTHPORT), Ltd., and GATISS, A. L. March 12, 1946; No. 7771. [Class 80 (ii)] In an axially engaged dog-clutch, one set of interengaging side faces of the teeth 38 are tapered circumferentially to facilitate disengagement under load, the ends of the teeth are inclined to a plane perpendicular to the clutch axis to allow ratcheting for synchronisation, and controllable positive locking means are provided tb maintain the clutch in full engagement, which locking means may be released by the clutch operating means for disengageinent. A driving shaft 10, driven from a prime mover through a hydro-kinetic transmission, carries an integral gear 11 meshing with a gear 12 rigid with a countershaft 13 which carries the freely-mounted wheels 14, 68 and the rotationally rigid dog-clutch sleeve 65. The gear 14 meshes with a gear 15, rotatably mounted on the output shaft 16, and the gear 68 meshes with a gear 62 rigid with a gear 63, both freelymounted on the shaft 61, which latter gear meshes with the gear 15. Slidably mounted on the output shaft 16 is a double dog-clutch sleeve 18 having teeth 19, 20 engageable with teeth 21, 22 on the gears 11, 15 respectively for direct or reduced drive, these teeth having inclined engaging faces 38 which tend to disengage the clutch under torque loading, and faces 37 parallel to the shaft axis to facilitate engagement under reverse torque conditions, the faces 59 of the teeth are also sloped to assist synchronous engagement. The splined portion 17 of the shaft 16 is slotted to receive two pairs of spring-loaded plungers 23, 24, which in extreme axial positions of the sleeve 18 pass through holes 27, or 28 to look the sleeve in engagement. A muff 29 encircles the sleeve 18 with an axial clearance and carries two cam blocks 31 which on axial movement of the muff 29 depress the appropriate plunger 23 or 24 during the initial movement through the axial clearance to allow the remainder of the movement of the muff to shift the clutch sleeve from one engaged position to the other, when the alternate plunger will pass through the appropriate hole in the sleeve to lock the latter in the new position. The muff 29 is controlled from a selector shaft 58 through a lever 52, the end 53 of which engages a slot in a block 45 slidable on a shaft 41 and having spring connection 46, 46a with two arms 43 integral with the muff and rigid with the shaft 41. Movement of the lever 52 causes compression of the springs 46, 46a until a collar 48 or 49 abuts the shoulder 51 of the shaft 41, whereupon the muff commences to move. If the dog-clutch teeth 19, 21 or 21, 22 are not synchronised, they will ratchet round under the load of the spring 46, 46a until such speed is reached, when the spring will finally engage the clutch which is then locked by the appropriate plunger. The shaft 58 may be rotated to cause the arm 57 to engage a lever 72 which controls in known manner a selector fork 69 operating a double dog-clutch sleeve 65 which provides direct reduced drive by clutching the shaft 13 to the gear 14 or reverse drive through the gears 62, 63 by clutching the shaft 13 to the gear 68.