Switching machine for a railroad

Abstract

A switching machine comprises a frame, a point detector bar, an indication contact assembly, at least one detector bar follower able to act on the indication contact assembly depending on the position of the point detector bar relatively to the frame, an inhibiting element jointly movable with the detector bar follower, and a cam bar translatable relatively to the frame between an unlock position and a lock position. The cam bar comprises a tongue portion which is able to be in contact with a stop of the inhibiting element when the cam bar is in its unlock position and to be away from the stop when the cam bar is in its lock position. The inhibiting element comprises a main body relatively to which the stop is vertically translatable between an active position and a passive position.

1 . A switching machine for switching the position of railway tracks, the switching machine comprising:
 a frame, intended to be fixed relatively to a pair of stock rails of a railroad switch,   a throw bar translatable relatively to the frame along a transverse direction to throw a pair of inner rails of the railroad switch, located between the stock rails, from a normal track position to a reverse track position, and from the reverse track position to the normal track position,   a point detector bar, translatable relatively to the frame along the transverse direction between a normal detection position intended to correspond to the normal track position of the inner rails and a reverse detection position intended to correspond to the reverse track position of the inner rails,   an indication contact assembly, fixed relatively to the frame, comprising at least one switch,   at least one detector bar follower, movable relatively to the frame between a proximal position, in which the detector bar follower acts on the switch, and a distal position, in which the detector bar follower is away from the switch, the detector bar follower being adapted to follow displacement of the point detector bar in such a manner that, when the point detector bar is in one of its normal and reverse detection positions, the detector bar follower is in a first position among the proximal and distal positions and, when the point detector bar is in an intermediary position between its normal and reverse detection positions, the detector bar follower is in the second position among the proximal and distal positions,   an inhibiting element having a main body and being jointly movable with the detector bar follower so that its main body is in a primary position when the detector bar follower is in its first position and in a secondary position when the detector bar follower is in its second position,   a cam bar having a kinematic connection with the throw bar in such a manner that the cam bar and the throw bar are jointly translatable relatively to the frame, the cam bar comprising a tongue portion and being translatable relatively to the frame along a longitudinal direction between an unlock position in which the tongue portion is able to be in contact with a stop of the inhibiting element, preventing the main body of the inhibiting element from reaching its secondary position, and a lock position in which the tongue portion is away from the stop, allowing displacement of the main body of the inhibiting element between its primary and secondary positions,   
       wherein the stop is vertically translatable relatively to the main body between an active position, in which the stop is in contact with the tongue portion of the cam bar when the cam bar is in the unlock position, preventing the main body from reaching its secondary position, and a passive position, in which the stop is away from the tongue portion of the cam bar when the cam bar is in the unlock position, allowing displacement of the main body between its primary and secondary positions. 
     
     
         2 . The switching machine of  claim 1 , wherein the inhibiting element comprises a biasing member biasing the stop toward its active position. 
     
     
         3 . The switching machine of  claim 1 , comprising a latch assembly to latch the stop in its passive position. 
     
     
         4 . The switching machine of  claim 1 , wherein the stop comprises a vertical shaft with a shaft body extending through a hole formed in the main body and, on top of the shaft body, a shaft head with a larger diameter than the diameter of the shaft body, and the switching machine comprises an actuation device to displace the stop between its active and passive positions, said actuation device comprising a plate assembly which is vertically translatable relatively to the frame, said plate assembly including a plate having a slot formed therein and through which the shaft body extends, said slot having a shape that follows the path of the shaft when the main body of the inhibiting element is displaced between its primary and secondary positions. 
     
     
         5 . The switching machine of  claim 4 , comprising a latch assembly to latch the stop in its passive position, wherein the latch assembly comprises a latch with a front face and a protrusion protruding from said front face, said latch being rotatable relatively to the frame around a horizontal axis between a latching position, in which the protrusion extends within a displacement region of the plate assembly, and a liberation position, in which the protrusion is out of the displacement region of the plate assembly, the position of the plate assembly when the stop is in its passive position being above the position of the protrusion when the latch is in its latching position, and the latch assembly further comprises a biasing element biasing the latch toward its latching position. 
     
     
         6 . The switching machine of  claim 4 , comprising a safety circuit to detect when the stop is in its passive position, said safety circuit comprising at least two stationary contacts and at least one mobile contact mounted on the plate assembly in a manner that, when the stop is in one of its passive and active positions, the mobile contact bridges the two stationary contacts, thus closing the safety circuit and, when the stop is in the other one of its passive and active positions, the mobile contact is away from the stationary contacts, thus opening the safety circuit. 
     
     
         7 . The switching machine of  claim 1 , comprising two detector bar followers, each one being adapted to act on a respective switch of the indication contact assembly when it is in its proximal position, the detector bar followers comprising a first detector bar follower whose main body is adapted to be in its second position when the point detector bar is in its normal detection position and a second detector bar follower whose main body is adapted to be in its second position when the point detector bar is in its reverse detection position. 
     
     
         8 . The switching machine of  claim 7 , wherein the stop of the inhibiting element of each detector bar follower is closer to the inhibiting element of the other detector bar follower when the main bodies of both inhibiting elements are in their secondary position than when the main bodies of both inhibiting elements are in their primary position, and the tongue portion of the cam bar has a median longitudinal axis which extends between both inhibiting elements. 
     
     
         9 . The switching machine of  claim 1 , wherein the point detector bar has a cylindrical surface in which a notch is formed, the detector bar follower is rotatable relatively to the frame around a vertical rotation axis between its first and second positions and has a follower part adapted for contacting the point detector bar in such a manner that, when the follower part is in contact with the cylindrical surface of the point detector bar, the detector bar follower is in its first position and, when the follower part is received in the notch, the detector bar follower is in its second position, the main body of the inhibiting element is rotatable relatively to the frame around a vertical pivoting axis, and the inhibiting element comprises a connecting rod connecting the detector bar follower to the main body. 
     
     
         10 . The switching machine of  claim 8 , wherein the point detector bar has a cylindrical surface in which a notch is formed,
 wherein the detector bar follower is rotatable relatively to the frame around a vertical rotation axis between its first and second positions and has a follower part adapted for contacting the point detector bar in such a manner that, when the follower part is in contact with the cylindrical surface of the point detector bar, the detector bar follower is in its first position and, when the follower part is received in the notch, the detector bar follower is in its second position,   wherein the main body of the inhibiting element is rotatable relatively to the frame around a vertical pivoting axis,   wherein the inhibiting element comprises a connecting rod connecting the detector bar follower to the main body, and   wherein the detector bar followers have a common biasing device comprising at least one spring having a first end attached to the main body of the inhibiting element of the first detector bar follower and a second end attached to the main body of the inhibiting element of the second detector bar follower, said common biasing device biasing both detector bar followers toward their second position.