Improvements in Apparatus for Operating Railway Switch Points and Signals

13,711. Johnson, A. H. June 15. Points and switches.-Relates to the operation of railway points and signals by electric power. In the arrangement shown in Fig. 1, for operating points, a continuous-current points motor m is employed, and, when the movement of the points is completed, a by-pass valve held closed by the electro-magnet v is opened to render further rotation of the motor ineffective in the manner described in Specification No. 11,005, A.D. 1905, this opening of the valve serving to break the circuit of the electro-magnet k of a gravity-controlled lock on the points and at the same time closing the contacts v of an indication circuit as described below. The hand slide l for controlling the points is fitted with the usual tappet l of the interlocking-frame, and with a slot i of known form for preventing the completion of the movement of the slide until the indication impulse is received from the points. The slot i co-operates with a pin i on a rod operated by a small quarterturn alternating-current motor i. When it is desired to reverse the points, the slide l is drawn forwards until it is stopped by the pin i at the shoulder adjacent to the rear inclined portion of the slot ill. The battery b then supplies current to the motor armature m through the contact spring h , wire o', relay coil y, choking-coil n , and motor field coil m , returning by the wire k and safety switch q . A parallel circuit, closed simultaneously, includes the contact-spring h , wire v , by-pass valve coil v, and the electro-magnet k of the points lock. At the same time the battery b supplies current to a continuous-current motor d driving a small alternating-current generator a. When the points are completely reversed, the switch p , p connected with the points establishes contact at 3, 5 and 7, 9, and at the same time the by-pass valve is opened and contact made at v . Alternating current then flows through a circuit comprising the wire a', relay tongue y', contacts 7, 9, v , wire v , condenser c, and alternating- current relay r. The resulting contact at r', r closes the secondary circuit of the transformer t, t through the motor i, and, as the primary circuit is established through the contacts 5, 3 and e', j, e, the motor i makes a quarter-turn and completes the movement of the slide l. The contact-springs j, h , h are thereby moved out of contact with the parts e', o, b , and the operating and indicating circuits are opened. The motor then stops, and the by-pass valv