Patent GB-698126-A (GB)
Title: Improvements relating to the automatic synchronization of driving and driven membersprior to such members being engaged
IPC: B60K23/02
Filed: 1951-02-26
Abstract: 698,126. Operating clutches. DAIMLERBENZ AKT.-GES. Feb. 26, 1951 [Feb. 24, 1950], No. 4697/51. Class 82 (ii). The main clutch c of a motor-vehicle is synchronised prior to engagement, e.g. after a gear-shift, by means such as two liquid pumps d, e, Fig. 1, or a single differentially-driven or differential pump 28, 29, Fig. 2, responsive to the difference in the respective speeds of the input and output shafts a, b of the clutch, acting directly on the engine-throttle n independently of the accelerator-pedal j, and positively put out of such action when the clutch is engaged, by additional means which is independent of the speed-responsive means. The clutch is operated manually or, Fig. 2, by interconnection with a gear-shift control. In Fig. 1, the connecting link between the throttle n and accelerator-pedal j includes a piston k and cylinder h connected to the respective members, and loaded by springs o normally holding the piston central to act as a rigid link. With the main clutch c disengaged a switch v energises a solenoid-valve r to close a passage q between the opposite ends of the cylinder thus rendering effective the synchroniser. Any difference in speed between the clutch input and output shafts a, b then causes the pumps d, e, on the respective shafts, to apply differential liquid-pressure on opposite sides of the piston k, thus moving the latter in the cylinder in one direction or the other to open or close the engine-throttle to synchronise the shafts a, b. The clutch c is then re-engaged, opening the switch v to close the valve r which constitutes the additional means above referred to for disabling the speed-responsive means and restoring normal connection between the accelerator-pedal and throttle. The passage q and valve r may be replaced by a permanent restriction w in the piston k. Fig. 2 has a pressure-operated clutch c actuated coincidentally with operation of a gearshift lever 1, which is moved between positions I and II in one or more planes to establish different ratios. In such movement the gear lever 1, through sector-and-pinion 3, 4 and crank 5, moves a piston-valve 7 through one complete stroke forwards (right) and backwards, the forward stroke, i.e. during gear disengagement, cutting off exhaust 14 and supplying liquidpressure from a pump 16 to a cylinder 13 for disengaging the main clutch c and a cylinder 12 which closes the engine-throttle n through a floating lever 22 linked to the accelerator-pedal j. The gear lever 1 also breaks a contact 43 to de-energise a solenoid-valve 37 to cut off the exhaust of a differential pump the two elements 28, 29 of which are connected respectively to the input and output shafts a, b of the main clutch c, to produce a liquid-pressure responsive only to the difference in speeds of the shafts. Since the engine-throttle has been initially closed by the cylinder 12, it will be necessary to accelerate the engine to produce synchronism which is achieved by the output of the differential pump 28, 29 acting on a piston 33, which turns a cam 36 (serving also as an idle-adjusting stop) opening the engine-throttle n until the shafts synchronise. During the later gear-engaging movement of the shift-lever 1, the valve 7 is returned to its original position, to exhaust the clutch and throttle-close cylinders 12, 13, permitting reengagement of the main clutch c, the final levermovement closing a contact 44 to exhaust the differential pump and restore normal throttle operation, this last action constituting the means for disabling the synchroniser.