GB843551A - Internal combustion engines and control mechanism for clutches therein - Google Patents

Abstract

843,551. Gearing for stopping and starting machinery. FICHTEL & SACHS A.G. Jan. 14, 1957 [Feb. 17, 1956], No. 1334/57. Class 80 (2). An internal combustion engine 11 drives the road wheels of a vehicle through a clutch 12 the engagement of which following a ratio shift is cushioned and controlled in dependence on the depression of the inlet manifold 27 and the speed of rotation of the engine. The clutch is disengaged when a lever 13 is turned on connecting a servomotor 15 through a valve 17 to the inlet manifold 27. The valve 17 comprises a solenoid 34, energized when the gear shift lever is operated to withdraw a valve closure member 19 and connect pipes 28, 16 leading from the inlet manifold 27 to the servomotor 15. When the solenoid 34 is de-energized after completion of the shift to re-engage the clutch 12, the pipe 16 leading to the servomotor 15 is connected through a hole 36 to a space 23. The pressure in the space 23 is thus reduced, so that atmospheric pressure acting through a hole 40 and space 22 can open a disc valve 18 against the bias of an adjustable spring 37. Accordingly the clutch 12 partially re-engages. The difference between atmospheric pressure and the pressure in the space 23 is now such that the spring 37 has once more closed the valve 18. Opening the throttle of the internal combustion engine 11 to increase engine speed reduces the pressure in the inlet manifold 27, i.e. increases the pressure within the manifold, and this increasing pressure acts through a pipe 29 upon a diaphragm 21 which accordingly moves to the right of Fig. 2. Either the engine lubricating system (not shown), or the engine cooling water pump 31, is connected by a pipe 30 to a chamber 25 containing a diaphragm 26. Increasing engine speed increases the water (or oil) pressure within the space 25, which acts upon the diaphragm 26 and moves it to the right of Fig. 2 against the bias of a spring 43 to act through a spring 42 and assist the rightward movement of the diaphragm 21 caused by increasing inlet manifold pressure. A stem 41 is thus brought into engagement with the valve 18, which is again opened, to allow the clutch 12 to complete its engagement. In a modification, Fig. 3 (not shown), the clutch 12 is electromagnetically engaged and the stem 41 acts successively upon contacts shunting out series resistors in the clutch control circuit. Specification 818,058 is referred to.