Patent GB-657044-A (GB)
Title: Electro mechanical device for controlling the movement of at least one movable member and controller embodying such device
IPC: G05G13/00
Filed: 1947-01-08
Abstract: 657,044. Sorting letters. CENTRE D'ETUDES M.B.A., MECANIQUE BALISTIQUE ARMEMENT. Jan. 8, 1947, No. 601. Convention date, Jan. 16, 1946. [Class 78 (i)] [Also in Group XXIV] An electro-mechanical control for preselectively moving one or a number of selector-rods 3 to one or more positions, for use e.g. as a controller in the postal sorting apparatus described in Specification 657,055, comprises a disc 1, frictionally mounted or fast on a shaft 2 which rotates continuously or only when a selection is to be made, the disc 1 being stopped in predetermined operative positions by energizing selector-solenoids (e.g. 27, Fig. 5) to cause their spring-returned armatures 7 to advance stops 6 into the path of facial projections 5, 5<1>, &c. on the disc 1, which latter is subsequently moved axially to cause one of a number of radial projections 4, 41, &c. thereon to engage a projection 8 on the selector-rod 3, thus moving it axially to the operated position. A number of selector-rods are grouped circumferentially around the disc 1, each associated with a solenoid-stop 7, 6, the disc having a different number of projections 4, 5 spaced so that only one rod is operated at a time. The discprojections 5 and stop 6 have co-operating projections and recesses 9, 10 to hold the disc until it is moved axially even if the solenoidstop 7, 6 is de-energized. In Fig. 5, the selectorrods 3 are moved axially through preselected different travels by a selected one of four discs 1, 51, 61, 71, on a common shaft 2 and having different initial clearances a, b, c, d between their projections 4 and axially-spaced coacting projections 48, 78, &c. on each selector-rod 3, so that when all the discs are thrust axially by the same amount, by a push-piece 56, acting on the common shaft 2 against a return-spring 58, the extent of travel of the selector-rod 3 depends on which disc 1 has been preselected to operate it. In addition, a fifth selected travel is provided by forming the first projection 48 on the selector-rod 3 as a step, with a fifth clearance e, Fig. 5B, between the top 38 of the step and the operating projection 4, means being provided for turning the selectorrod 3 to present the top 38 of the step to the operating projection 4 (as in Fig. 5B) so that the smaller clearance e becomes effective instead of the previous clearance a, the axial travel of the selector-rod 3 being increased by the difference between these clearances. The means for preselectively turning the selector-rod for this purpose comprises an additional fixed solenoid 57, the armature of which has a stop 70 against which a projection 69 on the selectorrod 3 is held by a torsion-spring 71 which applies torque to the end of the rod 3. Energizing the solenoid 57 withdraws the stop 70, permitting the torsion-spring 71 to turn the rod to the smaller clearance position shown in Fig. 5B. When, after executing the required axial movement, the rod 3 is released, it is returned axially by the torsion-spring 71, which acts also as a tension-spring, causing a pin 72 on the end of the selector-rod 3 to ride up an inclined surface 73 on the executive pushpiece 56, which turns the selector-rod back to its former position. The selector-rod performs a required operation through a lever 62 and rack-and-pinion 67, and the executive axial movement of the shaft 2 may perform an additional operation, not described, through a lever 68.