GB738226A - Improvements in and relating to automatically releasable shaft coupling and driving apparatus, especially for engine starters - Google Patents

Abstract

738,226. Turning gear. GRATZMULLER, J. L. July 27, 1953 [Aug. 6, 1952],No. 20791/53. Class 7(5). [Also in Groups XXIV and XXXII] A clutch comprises a driving member 6, Fig. 2, adapted to be shifted axially, a driven member, positive clutch elements 7, 8 on the two members interengageable when the driving member is shifted axially, a declutching spring 15 and a clutching spring 22, the clutching spring 22 being stronger than the spring 15, and means rotatively fast with the driving member to prevent the spring 22 from engaging the clutch in at least one angular position of the driving member. When the driving clutch member 6 is in the disengaged position, as shown, the clutching spring 22 acts on a pin 21, having a conical end, to push it against the surrounding casing and engage it loosely in a conical recess 23 in the driving clutch member 6. On rotation of the clutch driving member 6, the pin 21 rides out of the recess and the clutch is then engaged by the spring 22 overcoming the spring 15 to move the driving member 6 to the right of Fig. 2. When one rotation of the engaged clutch has been completed, the conical point of the pin again enters the recess and the clutch is disengaged by the spring 15. The device is described as applied to a starter for an internal combustion engine having a crankshaft 9, the driving clutch member being formed integrally with a pinion 1, axially slidable on a shaft 27 and engaging a rack 10, Fig. 1, by which it is turned on the admission of fluid from a hydraulic-pneumatic accumulator through a conduit 13 to a cylinder 12 formed by the rack support, the rack itself comprising the piston 11 in the cylinder. The rack 10 is returned to its initial position by a system of springs 14 when the pressure of the fluid in the cylinder 12 is reduced. The teeth of the pinion 1 are inclined to the axis of rotation to assist engagement of the clutch elements during the operative stroke. Various arrangements of springs in parallel and in series, Figs. 4 ... 9 (not shown), may replace the springs 14, the arrangement shown being found to require a comparatively short axial length. The shaft 27 carries a clutch member, having teeth 28 engageable with teeth 29 on a member fast on the crankshaft, and can be turned manually; alternatively the shaft 27 can be fast with the crankshaft and can drive a compressor. Specification 712,577, [Group XXVI], is referred to.