Patent GB-1234466-A (GB)
IPC: B60W30/18
Filed: 1968-08-27
Abstract: 1,234,466. Variable ratio gearing. F. E. AIZPIRI. 27 Aug., 1968 [12 Sept., 1967], No. 40930/68. Heading F2D. A vehicle gear change comprises at least two shafts each comprising connectible portions rotatable jointly or independently, gears and slidable clutches including single or double synchronization cones also mounted on the shafts, pistons connected to the sliding clutches, valves arranged to control the actuation of the pistons and change means arranged to control the system in dependence on the speed of the vehicle and connected to control the valves and a pedal for initiating action of the change means. Function summary.-The gear-box has various combinations of constant gears mounted on two or more shafts which are brought into engagement by the synchronization clutches. The output shaft drives a centrifugal governor which switches electrical relays to operate valves which admit pressure oil to piston/cylinder devices causing movement of the synchronization clutches when the clutch pedal is depressed to close the electrical circuit. Additional charges may be initiated by an electrical switch on a gear lever head. Fig. 4.-Constant mesh pinions P 1  . . . P 7  are engaged by single-ended synchronization clutches d 1 , d 2 , d 3 , d 4 , d 5 , d 6 , d 8  and d 9  and double-ended synchronization clutch d 7 . A centrifugal governor rc, driven by the output shaft e 1 , moves a switch arm b across contacts S 3  to energize the appropriate relays r when clutch j is depressed to establish the circuit through points 1, 2. The relays r moves valves v which admit oil pressure to pistons f to move the synchronizing clutches. A switch g allows forward or reverse running. A change-down can be initiated by pressing the accelerator pedal q when the clutch pedal j is depressed thereby energizing relay r 3  to energize solenoid b 3  thus causing the sector S 3 , carrying contacts p, to turn in relation to the switch arm b. In a modification the sector (S 3 ), Fig. 5 (not shown), is moved directly by the accelerator pedal. Fig. 6.-In a particular arrangement a relay r 2  (or r 1 ) energizes coil b 2  which attracts body y joined to a slide valve v overcoming spring u permitting pressure oil flow via conduit c 1  and passage x 1  to move piston f 1  and the synchronizing clutch d. Oil moved by the piston f 2  returns to the pump via passage x 2 . Conduit c 4 , b 5  returns trapped oil to the pump. Figs. 7 to 15 (not shown) illustrate the various speed changes possible with the arrangement shown in Fig. 1. In other embodiments the arrangement has gears arranged on three shafts (l 1 , l 2 , l 3 ), Fig. 2 (not shown), or three shafts (e 1 , e 2 , e 3 ), Fig. 3 (not shown), the various speed changes possible with this configuration being illustrated respectively in Figs. 16 to 25 (not shown) or Figs. 26 to 32 (not shown). In another embodiment a shaft (e 1 ), Fig. 33 (not shown), extends from a normal gear-box (cc), Fig. 40 (not shown), and carries pinions (P 1 , P 3 ) which are in constant mesh with pinions (p 2 , p 4 ) carried by a secondary shaft (l 2 ), either pinion (p 1 ) or (p 2 ) being selectively engageable with an output shaft by a double-ended synchronizing clutch (d 1 ). A governor (rc) moves a switch across contacts (p) to energize the appropriate relay (r) when the clutch pedal j has been depressed. In a modification of this embodiment a switch is incorporated in a gear lever head which permits preselection of an appropriate gear ratio before the clutch pedal is depressed, Figs. 41, 42A, 42B (not shown). Figs. 33-39 (not shown) illustrate the possible speed changes with the arrangement shown in Fig. 40. The electrical/hydraulic control arrangement in Fig. 6 is applicable to all embodiments.