Patent GB-599079-A (GB)
Title: Installation for the automatic control of change-speed gearing and clutch on a vehicle driven by an internal combustion engine
Filed: 1945-04-06
Abstract: 599,079. Controlling change-speed gears; operating clutches. DERUNGS, E. A., April 6, 1945, No. 8599. Convention date, March 30, 1944. [Class 80(ii)] [Also in Group XXVI] An electrically-executed manually or automatically initiated gear-shift in a three (or more) speeds and reverse gear on a vehicle, is automatically accompanied by two successive disengagements and reengagements of the main clutch AC, the first disengagement being used to neutralise the gear and also to complete synchronising circuits to a solenoid F, O, for closing or opening the engine-throttle CL according to whether the shift is to be up or down, actual engagement of the new ratio taking place during the second reengagement of the clutch. The period between the first re-engagement of the clutch and its second disengagement is subject to the action of an automatic timedelay switch, shown in Fig. 1 as a mechanical escapement IH, the delayperiod of which is automatically varied in accordance with the difference between the positions of the vehicle accelerator-pedal PA, and the throttle-solenoid FO, so as to allow a synchronising time which is suitable to those factors. The double declutch operation accompanies all shifts, whether manual or automatic, including shifts from neutral to first speed or reverse. Clutch re-engagement is retarded by a dashpot 50, automatically adjusted to suit the ratio in use and the function of which may be combined with that of the time-delay synchronising device. Clutch control is by a solenoid EMD, a manual pedal PD being also provided. Automatic shifts are operated jointly in response to vehiclespeed and the positions of the accelerator and brake pedals PA, PF. Gear-shift is executed by two threepositioned selectors 2, pivoting on a common rockshaft 4 and each connected to a sliding-gear in the change-speed gear (not shown). The selectors 2 are both moved to the neutral position shown, by disengagement of the main-clutch AC, which, through a rod 43, lost-motion connection 57, rockshaft 45 and lever 15, give a rightward movement to a selector - block 14, during which projections 8 on the block act on pairs of lateral arms 7 on the selectors 2. Gear establishment is effected by leftward movement of the block 14 under spring-load 20, selection being by energising one of four selector magnets I, II, III, R, on the block which thrust out plungers 11 for tilting forked members 1 whilst the block 14 is retracted so that, during the leftward return movement of the block, an arm of one of the forked members 1, engages an arm 5 of a selector 2 to tilt the latter in the appropriate direction to engage a gear. The clutch-disengaging solenoid EMD acts on the clutch-release collar 42 through a pair of cams 35, 36, the former, 35, of which is mounted on a pivot 37, whilst the latter, 36, carries arms 39, having at one end a pin-and-slot connection 40 with the cam 35 and at the other a pivotal connection with a bellcrank 41, which effects declutching when the solenoid EMD turns the cam 35 anti-clockwise on its pivot 37 to cause, through the cam 36 a bodily longitudinal movement of the arms 39. The cam 35 also acts directly on the gear-shift rod 43. The clutch engages at a rate controlled by a dashpot 50 actuated by the clutch-rod 43 and connected by a pipe 168 to a ported plug-cock 48, the body of which is connected to one of the ratioselectors 2, whilst the plug is connected to the other so that progressively increasing air-escape orifices are opened in the successive ratios, with the largest opening corresponding to neutral. The change-speed control comprises a manual selector switch CM having, as shown, five positions, providing reverse, neutral and three forward speeds (R, N, I, II and III), and a governor-controlled automatic switch SC, operated jointly in response to vehicle-speed and the position of the vehicle accelerator and brake-pedals PA, PF. The governor comprises centrifugal masses 134 radially slidable in a fixed axial plane on guide rods 134a secured, by means not shown, to a shaft 130, driven from the vehicle road-wheels through a pulley 131 and spring 132. The masses 134 act through links on an inner rotating sleeve 135a which carries the main non-rotatable governor-sleeve 136, which moves axially with the inner sleeve 135a (downwards with speed-increase) and can also be adjusted axially relative to the sleeve by turning a nut 137, mounted with rotational but not axial freedom on the sleeve 135a and screwing on a male thread 137 fast with the non-rotatable governorsleeve 136. The nut 137a is connected by cables to the accelerator- and brake-pedals PA, PF, depression of either of which turns the nut against the resistance of a return-spring (not shown) and screws the governor-sleeve 136 upwards. The governor-sleeve 136 controls three sets of contact-arms, one of which, 148, is biased by springs 150 to a central position and is moved through a slip connection with a serrated arm 141 on the governor-sleeve when the latter starts to move, so as to bridge contact-pairs 119, 120 or 121, 122 according to the direction of movement of the sleeve for an up- or down-shift, thus energising solenoid-windings F or O respectively for closing or opening the enginethrottle CL. A spring-connection 90, weaker than the accelerator-pedal return spring, between the throttle-spindle 85 and the accelerator-pedal PA allows the latter to move independently of the solenoid, which acts directly on the throttle-spindle through an arm 87. The other two sets of governor-operated contact-arms 142, 144 control respectively contact-banks, one of which, 143, controls the introduction of second speed, whilst the other, 145, controls third, as described below. The manual selector-switch CM has equivalent throttleopening and -closing contacts 30, 28 controlled by a spring-centred arm 31, and an additional arm 27 controlling selectorcontacts. Double declutching during a shift is due to the provision of a change-over switch CO operated stepwise through a ratchet 52 by the clutch-rod 43. The sequence of a shift from neutral to first-speed (or reverse), which does not involve automatic throttle operation, is as follows:-The lever 25 of the manual selector-switch CM is moved to position I (or R) and, before reaching the contact I the live arm 27 makes and breaks a contact 34, momentarily completing a circuit from a battery B to energise a polarised relay RT which closes and holds on contacts 101. The throttle-control switch-arm 31 is not moved by movement of the lever 25 to position I or R. On reaching contact I, the arm 27 completes a circuit from I, through governor switch-contacts 106, 114 (now closed with the governor collapsed as shown), selector magnet I, change-over switch-contacts 64, 62, the winding of a main relay-switch RV and the RT-relay contacts 101. Closing of the main-relay contacts RV completes a circuit (heavy lines) through the main-clutch solenoid EMD. The latter disengages the mainclutch AC, retracts the selector-block 14, and steps the ratchet change-over switch CO through 90 degrees, breaking switchcontacts 62, 64 and making 63, 65, which breaks the circuit of the selector-magnet I so that the magnet is inoperative. The circuit of the main relay RV remains closed through the change-over contact 63, switch-arm 54, resister R2, relay-coil RV, and additional contacts 102, (in parallel with 101), which are closed when the clutch-solenoid EMD begins its disengaging movement. At the end of the disengaging movement the clutch-solenoid EMD turns a lever 68, opening the contacts 101 and also opening the contacts of a time-delay switch IH which breaks the solenoidcircuit, thus permitting the clutch to reengage and the selector-block 14 to return to its operative position, but without effect since the selector-magnet I has been deenergised. The solenoid-operated contacts 102 are re-opened but the relay RT is now energised through the change-over contacts 63, 65, so that the contacts 101 close again and the main relay RV remains energised. A spring 70 automatically recloses the contacts of the switch IH after a time delay determined by the moment of inertia of masses 75 connected to the rocking pallets 74 of a mechanical escapement geared to the switch-plunger 71, such moment of inertia being variable by varying the radius of the masses 75 under control of a sliding member 77 set through a cable 80 connected to the arm 87 of the throttle-opening solenoid F, O, the cable sliding through an outer guide - sheath 81 abutting on an arm 82 connected to the accelerator-pedal PA, so that the differential setting between the acceleratorpedal and the throttle-operating solenoid, F, O, controls the position of the slide 77 and so the delay-period of the time-delay switch. Closure of the time-delay switch re-energises the clutch-solenoid EMD and effects the second clutch-disengagement during which the ratchet-switch CO is stepped a further 90 degrees, breaking contacts 63, 65 and re-making 62, 64 (as shown), so that, in the retracted position of the selector-block 14, the selectormagnet I is now energised and tilts its forked member 1 to an operative position ready for the return stroke, which takes place when the clutch solenoid EMD again breaks the contacts of the time-delay switch at the end of its travel. At the same time the solenoid breaks the contacts 101, which are not remade on re-engagement of the clutch since, their circuit through the change-over contacts 63, 65 is now broken. In the subsequent re-engagement of the clutch the operative member 1 of the selector-block 14 rocks the appropriate selector 2 to first speed position under spring-force 20, the final movement of the solenoid breaking the contact 102, thus de-energising the main relay RV and breaking the solenoid-circuit independently of the time-delay switch. The vehicle then