Patent GB-1015167-A (GB)
Title: Arrangement for the automatic control of multi-stage change speed gears for vehicles
IPC: F15B13/044
Filed: 1962-08-03
Abstract: 1,015,167. Electrically released switches. E. UHER. Aug. 3, 1962 [Aug. 4, 1961; Jan. 31. 1962. April 20, 1962], No. 29957/62. Heading H2B. [Also in Divisions F2 and H1] Relates to constructions of interlocked electrically operated switches used in changespeed gear control circuits (see Division F2). In one form, four main switch rods 462 ... 465, Fig. 22, are slidden from their open positions against the bias of springs 466 by selective energization of solenoids 458 . . . 461, the rods being mounted in a body 461 of insulating material. In their open positions, each switch, e.g. the switch 462, is in the position shown. A contact rod 474 slidable through the insulating body 461 is spring biased to the position illustrated, but contacts 474, 479 on this rod and on the main switch rod 462, respectively, are not closed. An interlock plate 472 slidable sideways through the insulating block 461 is biased by a spring 471 so that it engages with one or other of two cam-shaped lock notches in each of the main switch rods 462... 465. When an impulse is received by the solenoid 458 &c. of a switch it is desired to close, the armature of this solenoid initiates movement of the main switch rod, e.g. the rod 462. The engaged lock notch in the actuated switch rod 462 begins to cam the interlock plate 472 rightwards through the insulating body 461, to its disengaged position, and with the first movement downwards of Fig. 22 of the main switch rod, the contacts 474, 479 are closed, so that potential in a wire 457 is now applied through those contacts to the main switch rod. At the same time, already closed contacts 475 of a further switch rod transmit the potential of the wire 457 through a wire 476 to a solenoid 473, which is thus energized to slide the interlock plate 472 fully rightwards, against the bias of its spring 471, to a completely free position. Thus, any of the main switch-rods 462 . . 465 hitherto retained in their closed positions by the interlock plate 472, are now released, and are spring-returned to their open positions. As the downward movement of the actuated main switch rod 462 continues, the contacts 475 ultimately open, so that the solenoid 473 is de-energized and the interlock plate- 472 is biased once more by its spring 471 in its engaged direction. The downward movement of the operating main switch rod 462 continuing, ultimately contacts 477 on a further subsidiary slidable contact rod are made, so that the potential of the wire 457 is applied to a wire leading to a solenoid 438 for actuation of a ratio-shift valve. When the operating main switch rod 462 has completed its movement, the interlock plate 472 engages in a lock notch now presented to it, to retain the switch rod in its closed position. The speed of downward movement of each main switch rod 462 is damped by a simple pneumatic dash-pot, comprising a piston 468 fast with the end of the switch rod, and moving in a cylinder 467 from which air is expelled slowly through a bleed hole 470. When the closed switch rod is released by movement of the interlock plate 472, the switch rod is spring- returned rapidly to its open position, air then being drawn freely into the dash-pot cylinder 467 through a one-way ball valve 469. In a modification, a bar 536, Fig. 27, is reciprocated up-and-down by eccentric links 537, 538 driven from an electric motor 528, and the armatures 547 of solenoids 515... 518 are selectively projected into the path of the bar 536 so that the guides 519 ... 522 upon which the solenoids are mounted are slidden downwardly to effect closure of multiple switch contacts 532 &c., the closed contacts then being held closed by a spring-biased interlock plate 527 engaging with notches in the guides. In the disengaged position, each armature 547 and its associated solenoid, e.g. the solenoid 516, take up the position shown in Fig. 23, the armature being clear of the bar 536. When an electric impulse from a speed controlled ratioshift command apparatus is received by the solenoid 516, the armature 547 is projected into the path of the bar 536, as shown in Fig. 25, and simultaneously a switch 550 in the circuit of the electric motor 528 is closed. The electric motor 528 thus begins to drive, and the bar 536 moves downwards, carrying with it the armature 547 and its solenoid 516, and hence the guide 520 on which the solenoid is mounted. On initial movement of the guide 520, one of the switch contacts 530 is closed, for energization of a solenoid which slides the interlock plate 527 against the bias of a spring 526 to a position where it is clear of all the guide plates 519 ... 522. Thus, any switch previously held in its closed position is opened by the bias of associated springs 524 &c. At the same time, a cam 544 in a gear train 541 . . . 543, Fig. 24, transmitting drive from the motor 528 to the eccentric links 537, 538 and the bar 536, acts through a follower to close a switch 546 also in the motor control circuit and in parallel with the switch 550, so that although as the solenoid 516 &c. descends, the switch 550 is spring-biased to its open position, Fig. 25, the motor 528 is not switched off but continues to drive. When the guide 520 reaches the end of its travel, for final closure of the switch contacts 530, the interlock plate 527 is restored to its engaged position by spring bias, its disengaging solenoid meanwhile having been switched off, and the operated switch is retained in its closed position. Rotation of the motor 528 continues, to raise the bar 536 to its initial starting position, at which point the cam 544 has so turned that a dwellpoint 545 therein causes the switch 546 to be opened, thus switching-off the electric motor 528, until a further impulse is supplied to one of the switch solenoids 515 . . . 518.