GB755250A - Control means for moving a movable member from any one into any other of a first, second and third consecutive positions, for example in a reverse gear operating system for marine engines - Google Patents

Abstract

755,250. Electric selective signalling. PARSONS, J. B. Feb. 22, 1954, No. 5185/54. Class 40(1) [Also in Groups XXIV and XXXVII] The operating lever R of a reversing gear is moved between its forward, neutral and reverse positions by mechanism including a reversible electric motor 10 controlled by a three-way manual switch 25 in series with selector switch gear 17 operated by a rod 16 connected to lever R. The motor 10 may actuate lever R directly through toothed gearing or through a screw-and-nut connection, but as shown in Fig. 3, the motor drives a pump discharging, according to its directions of rotation, to one or other end of a double-acting fluid servomotor 13, the piston rod 14 of which is connected to lever R. The switch gear 17 comprises a casing with four pairs of contacts 21-22, 21a-22a, 29-29a and 30-30a, contacts 29 and 30 being connected respectively to the forward and reverse contacts 32 and 31 of switch 25, contacts 21, 21a being connected to the neutral contact 24 of switch 25, contacts 22, 29a being connected to the forward relay 10a of motor 10 and contacts 22a, 30a being connected to the reverse relay 10b of motor 10. Rod 16 carries four slidable contact discs 27, 28, 33, 37 has an enlargement 20 between discs 27, 28, and carries two adjustable abutments 18, springs 35 and 36 being arranged between discs 27, 37 and 28. 33, Fig. 4 shows the parts in neutral position, with discs 33 and 37 bridging across the contacts 29-29a and 30-30a while discs 27, 28 are held away from the other contacts by the enlargement 20. If switch 25 is now moved, for example, to forward position, relay 10a is energized and motor 10 turns forwardly to cause lever R to turn anticlockwise engaging forward gear. During the consequent rightward movement of rod 16 disc 37 remains in contact with contacts 30, 30a, disc 27 is moved further away from contacts 21, 22 disc 28 moves into contact with contacts 21a, 22a, and, at the end of the movement, the left-hand abutment 18 moves disc 33 away from contacts 29, 29a, so de-energizing the motor. the parts now occupying the positions shown in Fig. 5. If now switch 25 is moved back to neutral position, reverse relay 10b is energized via discs 28, and the motor turns reversely until the enlargement 20 moves disc 28 away from contacts 21a, 22a, to de-energize the motor. In a modified form of selected switch, rod 16 has secured thereto a carrier for three spring-loaded longitudinally-arranged contact strips co-operating with the four pairs of contacts. Specification 674,316 [Group XXVI] is referred to.