Patent GB-937130-A (GB)
Title: Power transmission
IPC: F16D48/02
Filed: 1962-05-24
Abstract: 937,130. Clutch control. TWIN DISC CLUTCH CO. May 24, 1962 [Aug. 3, 1961], No. 20015/62. Class 80 (2). A vehicle transmission includes an hydraulic friction clutch 106, the engagement of which is controlled by a pedal 136 conjointly actuating an inlet valve 98 and pressure-regulating valve 114. In addition, an indication is given to the driver upon initial clutch engagement to allow a pause in the operating movement of the pedal while play in the clutch is taken up. Transmission.-As shown, drive from a member 12, such as the flywheel, is taken directly to a power take-off shaft 54 and to a transmission sleeve shaft 23 through an hydraulic torque converter 14. The shaft 23 is connected by a multi-disc clutch 106 through a gear transmission to the vehicle axle. The torque converter is provided with an hydraulic lock-up clutch 43 for direct drive. Clutch details.-The discs 58 of clutch 106 are engaged against a pressure plate 57 by an actuator consisting of a fixed annular piston 63 and moving cylinder 64 providing a pressure chamber 67 and a centrifugal balance chamber 72 housing a Belleville release spring 74. Lock-up clutch 43 consists of a single disc 39 engageable with the converter housing 13 by an annular piston 33 operated by liquid supplied to a pressure chamber 35. Hydraulic supply and control system.-Liquid from a sump 94 is delivered by a pump 95 through a heat-exchanger 96 to the inlet and pressure-regulating valves 98, 114, from which it passes by pipe-lines 119, 120 to the torque converter 14 and main clutch pressure chamber 67 respectively. Liquid exhausted from the torque converter passes by a pipe-line 128 and restriction 89 to the balance chamber 72, and by a pipe-line 125 and connection 127 to provide a flow of coolant over clutch discs 58. A differential piston pressure regulating valve 123, 124 is fitted between pipe-line 125 and a branch line 121 from the main supply pipe 120. Pressure liquid for lock-up clutch 43 is supplied through pipe-lines 133, 124 branching from pipe 120 under the control of a manuallyoperated piston valve 129. Operation.-Upon allowing pedal 136 to rise under the action of loading springs 138, 141 from the neutral position shown, an arm 144, push-rod 145 and abutment member 147 first compress the loading spring 111 of the valve 98, which is moved to the left against a stop 107 to allow the admission of liquid to pipe-lines 119, 120. Further movement of the pedal is then effective to compress the loading spring 117 of valve 114 to regulate the pressure of the liquid in pipe-lines 119, 120. When the pedal reaches a position in which the supply pressure is sufficient to initiate engagement of the clutch discs 58 spring 141 is rendered ineffective by the prevention of any further upward movement of its retaining sleeve 140, the reduced feel on the pedal indicating to the driver that it should be held in that position while the clutch play is taken up. Subsequent pedal movement results in further compression of spring 117 and consequent increased pressure of the liquid supplied to clutch chamber 67. In the neutral position movement of the control valve 129 for the converter lock-up clutch 43 is prevented by the abutment of a stop 1À50 against the member 147, and the porting of the valve is such that the clutch cannot be engaged until member 147 has moved to a position for establishing a relatively high pressure in valve chamber 113. Should the pressure fall member 147 moves valve 129 to the right to connect the clutch to sump 94 in order to prevent slip. Instead of the pedal 136 a hand lever with an associated toggle link, Fig. 5 (not shown), may be used to operate valve push-rod 145, a spring detent indicating the clutch-engaging pause point, or an audible signal may be provided for this purpose.