Patent GB-420620-A (GB)
Title: Improvements in variable speed transmission mechanism
IPC: F16H63/30
Filed: 1933-10-05
Abstract: 420,620. Controlling variable-speed gearing and clutches. FLEISCHEL, G., BlÚneau, Yonne, France. Oct. 5, 1933, No. 27481. [A Specification was laid open to inspection under Sect. 91 of the Acts, April 6, 1934]. [Class 80 (ii)] In transmission gearing suitable for cars there is a "release device " 21<a>, Fig. 1, for the power operation of change-speed gearing 4 and a separate " release device " 21<b> for the control of an engine clutch 3. These two release devices are acted on by the same functional factor of the engine 2 such as a balancing governor 25, and are connected through a balancing beam 31 to common means such as a spring 30 opposing the governor. The governor 25 is geared to the engine shaft 1 and is free to slide so as to exert opposing balanced forces on a limb 34 of the gear release device 21<a> and through a balance lever 37 on a limb 35 of the clutch release device 21b and on a clutch - release - lock lever 39. The middle of the beam 31 is pulled upwards by the downward thrust of the spring 30 on the other arm of a lever 45 the pivot 46 of which is movable by the accelerator pedal 48 being connected thereto by a linkage 47, 10. Alternatively, the pivot 46 may be moved directly from the engine by suction at 50. A profile cam 53 controlled at 56 limits the displacement of the pivot 46 from a bowl 52. The gear release device 21a moves between contacts 23<m>, 23d which made circuit through a rotary switch 98 to a servomotor 22 which turns a gear-changing cam disc 19 one way or the other. The switch 98 is fast on the same shaft 81 as the cam disc 19, as shown in Fig. 11, and a worm-wheel 79 driven by the motor 22 is connected so as to turn the shaft 81 through 60‹ only at a time by a feathered clutch 83 controlled for the purpose by a cam slot 84 engaged by a fixed pin 85. The switch 98 cuts off current from the motor 22 when the shaft 81 has turned far enough. A main manual switch lever 96 is shown on neutral contact pm. When this is turned to contact ar, the shaft 81 is turned to reverse. When a contact av is engaged by the switch lever 96, automatically varying forward driving results. Forward speeds and reverse are brought in by links 14<a>, 14<b> engaging a shaped track 20<a>. A track 20d shown is for controlling a spragging device, not shown. If the motor 22 fails, the shaft 81, Fig. 11, can be turned by successive strokes of a hand lever 89 which has a finger 92 engageable with the teeth of a gear 93 and turned so as to turn the shaft 81 little by little. In the automatic action, the governor 25 acts on expanding to raise the release arm 21<a> and so to effect a gearing up in the gearing 4. It also holds up the clutch release arm 21b allowing the clutch 3 to remain engaged. The clutch is locked engaged by the spring lever 39 which engages the lower limb 35 of the clutch release 21b. When the speed of the engine falls, the governor 25 collapses and the clutch-release-lock 39 unlocks the release device 21b so that the latter falls on a contact 24d. Current then passes over a trip 61 to a coil 59 which brakes a disc 62 and a screw 64. A nut 65 constantly driven by the engine then pulls leftwardly the screw 64, a rod 68, and the clutch lever 69 which thus disengages the clutch 3. The disengaging action stops when the trip 61 is raised. The lever 69 is held on the tremble until the release arm 21<b> is raised by the governor. To obtain a free-wheeling effect, the clutch disengaging coil 59 may alternatively be excited by current from a switch lever 16 controlled by the accelerator 48. A pendulum mass 7 is operatively connected to the clutch release device 21b so as to disengage the clutch or sudden car acceleration, and a V-connection with the pendulum 7 is illustrated in Fig. 12, not shown, which opens the clutch for car accelerations in both directions. A number of alternatives for the screw clutch disengager 64 are described. In Figs. 15 to 17, not shown, there is a coil brake instead of the disc brake 62. In all these arrangements, the screw 64 is reversible so that the clutch can be re-engaged by its own springs. In Fig. 20, not shown, there is a pair of coil brakes, an irreversible screw and a differential, so that the clutch lever 69 is moved positively both ways. In Fig. 14, not shown, the brake 62 and screw 64 are replaced by a clutch and worm-and-wheel respectively. A different lay-out is illustrated in Fig. 21, not shown. The governor 25 acts in one direction on a ball joint at the centre of a disc which passes on the automatic control in a balanced manner to the two release devices, and to the clutch-release -lock which are similar in function to those of Fig. 1, but arranged differently according to Figs. 4-10, not shown. The gear-changing cam disc is operated through ratchet mechanism by the engine actuated clutch screw set going by solenoids excited by the gear-change release device. Specifications 356,139, 376,730, and 406,884 are referred to.