GB990410A - Automatic clutch - Google Patents

Abstract

990,410. Friction clutches; controlling clutches. B. HIRANO. Feb. 22, 1962 [Feb. 27, 1961; Feb. 28, 1961; March 14, 1961; May 19, 1961 (2); July 7, 1961; Aug. 21, 1961; Aug. 24, 1961 (2)], No. 6980/62. Headings F2C and F2L. A friction clutch has a sleeve hub connected to the driven shaft by a screw connection tending to move the hub in the plate separating direction when rotated in the driving direction relative to the driven shaft, torque being resiliently transmitted from the sleeve hub to the driven shaft. The engine shaft 1 of a motor which carries a drive pinion 2 which is positively clutched to the shaft through dogs 37, 38 on energization of an electromagnet 40 through closure of switch S1 controlled by centrifugal means or throttle position to the engine speed responsive, or of switch S2 closed by engine starting means. The pinion 2, which may alternatively be directly connected to the shaft 1, drives a gear 4 to which are splined driving clutch plates 7. Driven plates 8 are splined to a hub sleeve 9 having a threaded connection 14 with a thrust screw 10 slidable on the driven shaft 3 and rotatably connected thereto by a pin 12 axially slidable in a slot 11. The hub sleeve 9 is resiliently connected to the driven shaft 3 by a torsion spring 16, the action of the spring and the threaded connection 14 being such that torque transmitted in the normal driving direction tends to disengage the clutch against the action of the spring. Clutch engaging pressure may be provided by axial load of the spring 16 and of a second spring 13 acting on the thrust screw 10. The screw 10 may be moved axially to disengage the clutch by a push-rod 17. In a modification, the pinion 2 may be coupled to the shaft 1 by balls moved radially by a plunger axially shifted by the electromagnet 40. In a second embodiment; Fig. 3, speedresponsive balls 20 carried by the driving gear 4 allow progressively greater engagement with increasing engine speed by moving the release datum of the thrust screw 10. This embodiment may be modified by mounting the centrifugal assembly externally of the clutch to act through the push-rod 17 or by similarly moving the push-rod or pin 12, through a screw-andnut mechanism acted on by a friction brake. In other embodiments the centrifugal balls may act between the driving gear 4 and the clutch plates 7 at chosen characteristic rates. In another modification, the push-rod 17 may be electromagnetically latched in the clutch disengaged position until the engine throttle is set to provide sufficient engine speed for acceleration from a standstill.