Patent GB-443718-A (GB)
Title: Improvements in the control of automobile variable-speed gears and clutches
IPC: F16H61/00
Filed: 1934-08-24
Abstract: 443,718. Controlling change-speed gearing; friction clutches. BARKER, G. G., 14, High Holborn, London.-(Bendix Aviation Corporation; 105, West Adams Street, Chicago, U.S.A.) Aug. 24, 1934, No. 24447. [A Specification was laid open to inspection under Sect. 91 of the Acts, Feb. 26, 1935.] [Class 80 (ii)] [See also Group XXXI] A single-acting fluid-pressure and/or electric motor moves a conventional motor-vehicle gear-shift lever 16 laterally, against permanent spring-bias, out of the channel for selecting second and high speeds, into that for first and reverse speeds. A longitudinal, double-acting, fluid-pressure motor 28 establishes a gear, under the selective control of a heel-and-toe treadle 138. Speed-responsive means automatically energizes the singleacting motor when the vehicle comes to rest, and also neutralizes the gear. The motive fluid is engine-suction, under control of a common valve 30, operated by release of the vehicle accelerator-pedal 20, for simultaneously energizing a main-clutch withdrawal motor 26. In Figs. 1-4 the gear-establishing motor 28 is pivoted to the vehicle dash-board 12 and its piston-rod 72 is secured to the shifterlever 16 so that the motor swings laterally with the lever. A spring 86, Fig. 3 (plan), permanently biasses the motor 28 and lever 16 into engagement with the channel for second and high speeds, whence they are moved laterally (i.e. downwards in Fig. 3), into the first and reverse channel by a single-acting diaphragm 76 acting on the motor 28 through a lever 80 and fulcrum 82. Suction is directed to either side of the gear-establishing cylinder 28 under control of a piston-valve 88, spring- loaded to a neutral position and operated through linkage 142 by the heel-and-toe treadle 138. The housing of the valve 88 is arranged between the diaphragm-cylinder 74 and the gear-establishing cylinder 28, and has a suction inlet-port 100, Fig. 4, connected by a conduit 54 with the clutch-control-valve 30; an atmospheric-port with an air-cleaner 116 ; a port 122 leading directly to the front end of the cylinder 28, and a port 102, leading through a tube 106 to the rear end of the cylinder. An additional valve 90 controls a port 162, leading directly to the diaphragmcylinder 74, and also a port 152 leading through a tube 160 to the centre 210 of the gear-establishing cylinder 28, so that when this valve is retracted, against an inward spring-force, it uncovers these ports to neutralize the shifterlever and simultaneously bias it into the channel for first and reverse speeds. This action takes place automatically when the vehicle stops, the valve 90 being actuated by a solenoid 170, controlled through a relay 180, 182, through a circuit comprising a series arrangement of three switches, viz. an engine ignition-switch 174, Fig. 11, a master-switch 176 and a switch closed automatically by the vehicle-speedometer 178, when it reaches the position of rest. An emergency manualswitch 232 is shunted across the switches 176, 178. In order to allow the vehicle to be started in second-speed there is a switch 216, which, at the first downward movement of the valve 88, by toe-pressure on the treadle 138, breaks the solenoid-circuit and releases the valve 90, thus de-energizing the diaphragm 76 and allowing the spring 86 to bias the shifterlever 16 to the right, before the valve 88 has become effective. To provide for reverse, this switch 216 can be short-circuited by a manual push-button 230. The clutch-actuating cylinder, Fig. 16, (not shown), is the same as that described in Specification 399,377 and comprises a bleed-valve connected to the accelerator-pedal and a manually-operable valve for over-riding the automatic action. In Figs. 14 and 15, (not shown), the diaphragmcontrolling valve 90, Fig. 4, is operated directly by a centrifugal-governor or fluid-pump on the driven shaft. Modifications of the electrical circuit shown in Fig. 11 are also shown, the simplest of these having only a simple manual switch for directly energizing the solenoid 170, no relay being provided. In Fig. 17, the shifter-lever 472 is cranked behind the instrument-panel 480, and can be manually operated by a handle 508, hinged to a socketed link 478, operated through a bellcrank lever, by a fixed double-acting motor 463. The shifter-lever is moved laterally through the gate, towards the second and high speed channel, by a tension-spring connected to the socketed part 494, and towards the first and reverse speed channel, by a single-acting solenoid connected by a cable to the part 494. To provide for the automatic features referred to in connection with Figs. 1-4, this solenoid is arranged in parallel with the solenoid 170, Fig. 11, of the valve 90, which latter now serves only for neutralizing purposes. Specification 442,204, also is referred to. The Specification as open to inspection under Sect. 91 describes an arrangement in which the shifter-lever is manually moved laterally against the spring-bias into the channel for first and reverse speeds, no power being provided for this purpose. Fig. 23 (Cancelled) shows a modified form of gearestablishing motor used in such an arrangement, the piston 410 of the motor constituting its own selector valve. The piston is provided with ports 440 and is mounted for limited axial movement on a ported hubmember 422 communicating through a central tube 444 with a suction port 426, and through an outer tube with an atmospheric port 458. Springs 456 load the piston one way or the other in its end positions, to direct the suction to the appropriate side of the piston, and the arrangement is such that repeated strokes of an operating treadle, always in the same direction, and directly acting on a simple spool-valve, governing the supply of suction or atmosphere to the port 426, cause alternate backward and forward strokes of the pistonrod 414. Automatic change between second and high speeds is thus obtained simply by repeated depressions of the treadle, and release of the accelerator pedal. As before, the gear may be neutralized by a solenoid-valve controlling a port at the centre of the cylinder. In a modification of this form, a heel-and-toe treadle acts through linkage on a piston slidevalve, supplying suction or atmosphere to either side of a gear-establishing cylinder containing a simple piston. One construction makes use of a main-clutch operated by a combination of centrifugal and vacuum means. When this clutch takes up drive, the light initial engaging-pressure supplied by centrifugal masses 390, Fig. 17 (Cancelled), is augmented by the main-springs 398, as the suction in the cylinder 358 is reduced. The masses 390 act through a presser-plate 380 on a ring 382. When this clutch is used, the gear and clutch actuating - cylinders are connected directly with the engine induction-pipe, instead of to a clutch control-valve, and the engine throttle-valve serves as a common control. The clutch-operating cylinder 358 has a fixed bleed in a spring-loaded checkvalve 406. The piston-rod of the gearestablishing motor may be connected to the shifter-lever by soft rubber sleeves or by ball- and-socket joints. This subject-matter does not appear in the Specification as accepted.