Patent GB-254789-A (GB)
Title: Electrical railway traffic control devices
IPC: B61L5/06
Filed: 1925-04-06
Abstract: 254,789. Reichard, W. H. April 6, 1925. Interlocking and controlling and locking.-In an electrically-operated control device adapted to control the opening and closing of circuits or a mechanical device, or both, and particularly suitable for controlling the movement of railway switches, the lever is unlocked by the combined action of two circuits, one of which is energized bv the motor running due to its inertia, and the other from an applied source when the device assumes a predetermined position, Specification 169,795 is referred to. As described, the circuits are connected with the windings of an electromagnetic device, Fig. 1, comprising cores A, B, C<1>, C<2>, X, core X being supported at one end on core C<2>, its free end extending towards C<1>. The cores A, B, X have windings D, I, N respectively. The device is supported on the frame K of an interlocking machine. Two armatures Y, E are provided, armature Y serving, when attracted, to raise a plunger H, H<1>. Armature E may be attracted towards core C<1> or core X, in the latter case serving to close a contact M. Core A is of greater cross-section, and core X of less crosssection, than cone B, and the arrangement is such that when winding I alone is energized, neither armature is attracted, when current of the same polarity flows simultaneously in windings D, I, armature Y is attracted, when winding D alone is energized armature E is attracted to core C', when current flows through windings D, N in series no movement of armature E occurs, and when winding N alone is energized armature E is attracted to core X. Fig. 2 shows the application to controlling the movement of switch points 85 effected by a motor 60 in response to movement of a lever 50 (which may be one of a series) in an interlocking machine, the parts being shown in normal position for a straight road. A source of applied current V is connected through contacts controlled by a no-volt release coil P to bus bars O, O<1>. Assuming contact M closed, coil P is initially energized by momentarily closing a switch S to short-circuit a resistance R in series with coil P. Lever 50 is connected with, and operates, a circuit controller Z, and the points 85 are connected to a slidable plate MP having cam slots serving to operate circuit controllers NC, RC. When lever 50 is moved in the same direction of the arrow to reverse position, a sliding bar J connected therewith is moved to the left until a dog or detent j is forced into a recess in frame K by contact with a fixed member 90, and rests on the plunger head H<1>. Controller Z is also moved to close a circuit from bus bar O through the reverse field winding RF uf motor 60, contact 29 of controller NC, armature of the motor, winding N, to bus bar 0'. At the same time a shunt circuit is closed through the winding RM of a motor reverser, whereby a core RC<1> is attracted and causes a contact U to bridge contacts 26, 37 so that current is still supplied to the motor armature, although the previous field and armature circuits become broken at contact 29 when the motor operates to move the points 85, plate MP, and controllers NC, R.C. This movement causes contact 53 of controller RC to close an energizing circuit through winding I. At the same time contact 49 closes a circuit from the positive brush of the motor through the motor normal field winding NF, and windings D. N to the negative brush, and as the motor continues to run by its inertia and acts as a generator, windings D, N are energized, and as winding I is also energized, armature Y is attracted, thus causing the plunger H to raise detent j, allowing movement of lever 50 to be completed. To protect against unwanted return of the points 85 to normal position by supply of current to the fieldwinding NF, now in circuit, from bus-bar O, such current finds a path through winding D and attracts armature E to open contact M, thus deenergizing the release-coil P and cutting off the source V before the motor has time to effect appreciable movement.