Patent GB-1279575-A (GB)
Title: Improvements in or relating to automatic clutch control device for motor vehicles
Inventor: WEYMANN CHARLES TERRES
IPC: B60K17/34
Filed: 1970-01-23
Abstract: 1279575 Clutch control SIDARO SOC INDUSTRIELLE DE DISPOSITIFS AUTOMATIQUES ROBOMATIC 23 Jan 1970 [3 Feb 1969] 3359/70 Heading F2L An electro-pneumatic clutch control for a motor vehicle comprises an electromagnetically operated valve 9 which on closure of an engine speed responsive governor controlled switch 6 or a gear shift lever controlled switch 114 connects a clutch disengaging servo-motor 2 to a source of pressure air or (as shown) a vacuum reservoir 111 for clutch disengagement and on re-opening of the switch 6 or 114 connects the servo motor 2 to atmosphere through an engine speed responsive governor controlled valve 5 and/or an electromagnetically operated valve 8 controlled by the position of the clutch disengaging servopiston 13. An engine speed responsive governor 21 pivots a lever 4 against the bias of a spring 26. The lever 4 carries the movable element 31 of the valve 5 which initially opens at a first predetermined speed and thereafter is increasingly opened with increasing engine speed. The lever 4 additionally carries an adjustable contact 38 of the switch 6 which is opened at a second predetermined speed at most equal to the first predetermined speed. At a third predetermined speed an adjustable stop 51 carried by the lever 4 engages a spring pressed piston 46 which reduces the movement of the lever 4 with increasing speed. The tension of the spring 26 and the compression of the spring 47 may be adjusted by screws 27, 48. A valve element 81 of the valve 8 is normally biased to an open position and is closed when an electromagnet 83 is energized through a switch 96 or 97 respectively closed when the gear lever 101 is in first or reverse ratio and through a switch 98 which is closed when the piston 13 approaches the clutch engaged position. The piston 13 is connected to the normal clutch pedal 1 by a fluid column 15. Operation.-Below a predetermined engine speed the switch 6 is closed to energize an electromagnet 67 which opens the valve 9 to supply suction to the clutch disengaging servo 2. If first ratio is engaged the switch 96 is closed and thereafter on increased engine speed the switch 6 opens to de-energize the electromagnet 67 and connect the servo 2 to atmosphere through the valve 5 and the valve 8. The piston 13 moves rapidly in the clutch engaging direction until the switch 98 is closed to energize the electromagnet 83 and thus close the valve 8 whereafter the servo 2 is connected to atmosphere through the valve 5 alone to provide slow final clutch engagement. Starting in reverse ratio is similar to the above with the switch 97 closed in place of the switch 96. For ratio shift the clutch is disengaged by closure of a gear shift lever switch 114 which energizes the electromagnet 67 to supply suction to the clutch disengaging servo 2. On completion of ratio shift the servo 2 is connected to atmosphere through both the valve 5 and the valve 8 for rapid clutch engagement. The rate of flow through the valve 8 may be adjusted by a throttle screw 88. In Fig. 2 (not shown) the fluid column (15) is connectible directly to a clutch slave cylinder (115). A valve (118) being provided between the usual clutch master cylinder (117) and the slave cylinder (115) which valve normally connects the master cylinder to the slave cylinder but on energization of a solenoid (125) connects the fluid column (15) to the slave cylinder (115). A switch 128 energizes the solenoid 125 on initial movement of the clutch disengaging piston 13.