US2772844A - Railway switch connecting rod - Google Patents

Description

' Dec. 4, 1956 J, J, MCGOWAN 2,772,844

RAILWAY SWITCH CONNECTING YROD Filed Dec. 16, 1952 f q I 2 &5 la 4 3' o a 4 9 10 17 15 19 V i Q g I g V O o o o o 00 mmvrim HIS ATTOR VEZY United States Patent O RAILWAY SWITCH CONNECTING ROD Kenneth J. J. McGowan, Pittsburgh, Pa., assignor to Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania 1, Application December 16, 1952, Serial No. 326,333

l. I 5 Claims. (Cl. 246-452) My invention relates to railway track switch operating apparatus and has particular relation to a safety device controlling the operation of switches of the type which are at times trailed." i

- The present application-is a division of iny copending rod interconnecting the switch points of the switch. Such switches 'are sometimestrailed causing damageto the switch points and breakage of the switch stand cranks or of the pins used in interconnecting the switches with the switch stands. Subsequent tratfic movements over 'a trailed switchof this typeeither in a trailing direction or in.a facing point direction are hazardous since the switch points are no'longer held in either of their two extreme positions. Repairs to the switch and the switch stand are necessary before traflic movements may again be made over the switch.

Various mechanismshave been proposed to permit the trailing of a switch without damage to the switch or its associated switch stand. One such mechanism provides as'pring biased plunger and cylinder arrangement interconnecting the head rod of a switch with the operating crank of a, switch stand, theplunger being held in po-' sition relative to the cylinder by shear pins. A trailing move inthis instance breaks off the shear pins permitting the plunger tomove the switch to its opposite extreme position. To operate the switch for subsequent moves, the plunger is returned to its operating position against the bias of the charging spring and the broken shear pins replaced. i

It is an object of my invention to provide novel and improved switch operating apparatus for automatically reversing a switch when the switch points thereof are moved a predetermined distance by. the wheels of a trailing apparatus embodying my invention, and shall compression members holding therollers within the spring cam troughs so that both the spring cams and the cam rollers will be moved together upon operation of the switch stand to move the switch points to their normal or reverse positions. Should the switch be trailed in either of its two extreme positions, the cam rollers will be moved relative to the spring cams. The contours of the spring cams are such that after a small initial movement of the switch points by the wheels of the trailing vehicle, the increased bias of the compression members will force the rollers over the working surface of the spring cams which will cause the cam rollers to be moved in the same direction to move the switch points over to their extreme opposite position. The bias of the compression members and the spring cams, and the particular contours of the cams, will hold the switch points in' their extreme opposite positions until the switch stand is operated to its opposite position. The cam rollers will then be forced back into the center recesses or troughs of the spring cams where they will beheld while the switch stand is operated to move the switch points back into their original extreme positions. Other objects and characteristic features of my invention will become apparent as the description proceeds.

I shall describe one form ofa railway switch operatpoint out'the novel features thereof in claims.

In the accompanying drawings:

Fig. 1 is a top plan view showing a switch provided with one form of a railway switch operating mechanism embodying my invention, while i Fig. 2 is a top view showing on an enlarged scale the switch operating mechanism embodying my invention illustrated in Fig. 1 with the cover removed.

Referring to Fig. 1, the reference character A designates a railway track switch comprising two fixed rails 1 and 1a and two movable rails or switch points 2' and 2a, the switch points being connected adjacent their ends by a head rod 3. When the switch occupies its normal position, as illustrated in Fig. 1, the switch point 2 engages the fixed rail 1 and the switch point 2a is spaced from the fixed rail 1a. When the switch A occupies its reverse position, the switch point 2a engages the fixed rail 1a and the switch point 2 is spaced from the fixed rail 1.

Spiked or otherwise securely fastened to the ties adjacent the switch A is a switch stand 4 of the. usual type comprising a weighted hand-throw lever' 5 secured to the outer end of a shaft 6, the inner end of the shaft having secured thereto a pinion 7 meshing with a gear segment 8. Thegear segment 8 is secured to a vertically disposed shaft 9 suitably journaled within the housfor moving the switch points to their normal and reverse the cam rollers will be held in centrally located recesses housing opposite the threaded opening 16l 'Ihje and;

the shaft 9 extending below the bottom of the housing and having secured thereto a crank arm :11. The crank arm 11 is pivoted to a crank rod 12, the crank rodbe-. ing secured to the switch operatingmechanism embodying my invention and designated generally by. the ref-i erence character B.

The switch operating 'mechanism B embodying invention comprises a housing 13 (Fig. 2) adapted to be closed by a cover 14, the housing-being supported for sliding movement on a plate or rollers (not shown) in a well-known manner. with an exterior boss 15 which is suitably drilled and threaded as at 16, for receiving the crank rod 12 fixed to the crank 11 of the switch stand 4, the crank'rod being securedby a lock nut 17 and lock washer 181 A connecting rod 19 connected by a link2 0 to the head The housing-13 is formed rod 3 of the switch A is slidably received within the housing 13 through. a bearing provided in the *side' of the of the connecting rod 19 within he housing .13 is threadedly secured to a bifurcated trolley 22 having rotatably secured thereto as by pins 23, two oppositely extendingcam rollers 24, The two cam rollers cooperate with similar Opposing spring cams 25, both cams being made of heavy gauge spring steel, the ends of the cams being mounted with some clearance in'recesses 26 provided in the interior walls of the housing 13.

The spring earns 25 are formed with center troughs 25a and moving toward the right in Fig. 2, the'troughs 25a are followed by rises or inclines 27aterminating in crests 2.8a, the crests being followed by declines 29a terminating in end troughs 30a; The left sides of the spring earns 25 are similar, the center troughs 25a being followed by rises 27b, crests 28b, and declines 29b terminating in end troughs 30b. The distance between the center troughs 25a of the spring cams and the end troughs 311a and 30b is equal to the throw of the switch points 2 and 2a. The crests 28a and 28b of the spring cams are approximately one third the distance between the center troughs 25a and the end troughs 30a and 30b.

Cooperating with each of the spring cams 25 are contoured spring retainers or compression members 31 formed to fit the back surfaces of the cams opposite the center troughs 25a. The compression members 31 are urged inwardly toward the center of the housing by coil springs '32 interposed between the members 31 and the end walls of the housing 13, the end walls being formed with bosses 33 for retaining and centering the ends of-the springs.

the bias of the coil springs 32 will retain the cam rollers 24 within the center troughs 25a of the spring cams when the hand-throw lever is operated to move the switch points .2 and 2a to their-normal or reverse positions. In the event the switch A is trailed while in its normal position, the movement of switch points 2 and 2a a distance of approximately two inches by-the trailing wheels toward their reverse positions will move the connecting rod 19 to the right a sufiicient distance to move the cam rollers 24 opposite the crests 28a of the spring cams. The movement of the cam rollers to the right will tend to compress the coil springs 32 and deform the spring cams 25. Upon passing the crests 28a of the spring earns, the horizontal components of the forces exerted by the compressed springs 32 and the deformed spring cams force the rollers farther to the right into the end troughs 30a, the movement of the cam rollers to the right causing the switch points 2 and 2a to be moved to their full reverse position wherein they will be held until the hand-throw lever 5 is operated to its reverse position and returned to its normal position to return the switch points to their normal position. With the switch points 2 and 2a moved to their full reverse positions by the switch operating mechanism B, the

operation of the hand-throw lever 5 to its reverse posi- 32 forcingthe rollers into the end troughs 30b to move the switch points to their full normal position. Operation of the hand-throw lever first to its normal position and then to its reverse position will return the switch points2- and 2a to their reverse positions.

It will be apparent from the foregoing description of my invention, that successive trailing moves over the witch A may be m de, he swi ch poin being r v r e during each trailing move. Considering for'the moment that the switch A is trailed while in its normal position,

' In the operation of the switch operating mechanism B,

he cam rollers 24 will have been moved into the .end trough 30a of the spring earns 25. The switch points 2 and 2a will be in their full reverse positions but the hand-throw lever 5 will be in its position correspond ing to the normal position of the switch points. A vehicle trailing the switch A under such circumstances will move the switch points to the left to move the connecting rod 19. The cam rollers 24 will be moved to the left to restore the cam rollers 24 to the center troughs.

25a. The positions of the switch points, cam rollers and hand-throw lever now correspond to the normal positions occupied before the switch A was trailed. The mechanism is thus in condition for operation in the normal manner or to provide the automatic reversal described in the event the switch is again trailed The operation of the switch operating mechanism B will operate in a similar manner when the switch A is trailed while in its reverse position and then subsequently trailed, thereby restoring the mechanism to its reverse position.

In addition to the advantage of permitting successive trailings of the switch, the mechanism hereinabove described may be incorporated between any switch operating mechanism and the associated switch points and will convert the switch to operate for safe trailing movements.

Although I have herein shown and described only one form of railway track switch operating apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims Without departing from the spirit and scope of my invention.-

Having thus described my invention, what I claim is:

1. Apparatus for interconnecting an element of a railway switch with an element of a switch stand, comprising a deformable spring cam for connection with one of said elements and having. symmetrical working surfaces about a median point, a cam follower-for connecion with the other of said elements and cooperating with the working surfaces of said cam, and resilient means biasing the median point of .said cam in engagement with said cam follower to maintain said cam follower in engagcment with said cam at its medianpoint when said switch stand element is operated to throw said switch, the working surfaces of said cam being such that when said switch element is moved by a trailing vehicle the bias of said resilient means is increased and said cam is deformed due to the relative movement between said cam follower and said workingsurfaces, a predetermined relative movement between said working surfaces and said cam follower permitting thestressed resilient means and the deformed cam to increase the relative movement between said working surfaces and said cam follower toreverse said switch.

2. In combination with a railway switch and a switch operating mechanism operable between two extreme posi- V tionsfor. moving saidswitch to its normal and reverse positions, two symmetrical, opposing spring cams operatively connected with said operating mechanism, a cam follower cooperating with said spring cams and operatively connected with said switch; and resilient means cooperating with each of said spring cams tending to bias said cams toward each other, said resilient means and spring cams-being such that said cam follower is retained relative to said earns when said cams are moved by said operating'rnechanism to move 'said' switch to its normal and reverse positions; the trailing of said switch moving said cam follower in a corresponding direction to move said cam follower relative to said cams against the bias of said resilient means and deforming said earns, the movement of said cam follower arpredetermined distance by said trailed switch permitting the bi'ased'resilient me ns and deformed spr ng ams t move said e rn fol- 1 lower an addit' nal distance in the direc ion he c mfollower was riioved by the trailed switch to reverse said switch. a

3. In combination with a railway switch and a switch operating mechanism operable between two extreme positions for moving said switch to its normal and reverse positions, two symmetrical, opposing spring cams operatively connected with said operating mechanism, each of said cams having center troughs and end troughs with crests therebetween, the distances between the center trough and end troughs of each spring cam being approximately equal to the throw of said switch, the crests between the center and end troughs of each spring cam being approximately one third the distance from the center trough to the end troughs; a cam follower engaging both of said spring cams and operatively connected with said switch; and resilient means cooperating with each of said spring cams adjacent the center troughs thereof tending to bias said cams toward each other, said resilient means and spring cams being such that said cam follower is retained in engagement with the center troughs of said cams when said cams are moved by said operating mechanism to move said switch to its normal and reverse positions; the trailing of said switch moving said cam follower in a corresponding direction out of engagement with said center troughs of said cams against the bias of said resilient means and deforming said cams, the movement of said cam follower over the crests of said spring cams permitting the biased resilient means and deformed spring cams to move said cam follower into engagement with the end troughs of said cams thereby reversing said switch; the operation of said operating mechanism to its extreme position corresponding to the extreme position to which the trailed switch was moved, moving said cams relative to said cam follower to force said cam follower back into engagement with the center troughs of said spring cams.

4. In combination with a railway switch and a switch operating mechanism operable between two extreme positions for moving said switch to its normal and reverse positions, a housing member operatively connected with said operating mechanism; two symmetrical, opposing spring cams within said housing member; each of said cams having center troughs and end troughs with crests therebetween, the distances between the center trough and end troughs of each spring cam being approximately equal to the throw of said switch, the crests between the center and end troughs of each spring cam being a predetermined fractional portion of the distance between the center trough and the end troughs; a cam follower including opposing cam rollers cooperating with said spring cams and operatively connected with said switch; and resilient means cooperating with each of said spring cams adjacent the center troughs thereof tending to bias said cams toward each other, said resilient means and spring cams being such that said rollers of the cam follower are retained in the center troughs of said cams when said housing member is moved by said operating mechanism to move said switch to its normal and reverse positions; the

trailing of said switch moving said cam follower in a cor-' V responding direction to move said cam rollers out of said center troughs of said cams against the bias of said resilient means and deforming said cams, the movement of said rollers past the crests of said spring cams permitting the biased resilient means and deformed spring cams to move said rollers into the end troughs of said cams thereby reversing said switch; the operation of said operating mechanism to its extreme position corresponding to the extreme position to which the trailed switch was moved, moving said housing member relative to said cam follower to force said cam rollers back into the center troughs of said spring cams.

5. Apparatus for interconnecting an element of a railway switch with an element of a switch stand, comprising two deformable spring cams for connection with one of said elements disposed in confronting relationship, each of said cams having a center trough and two end troughs with crests therebetween, the distance between said center trough and the two end troughs being approximately equal to the throw of the railway switch, the crests between said troughs being a predetermined fractional portion of the distance between said center trough and said end troughs, a cam follower cooperating with the surfaces of both said cams for connection with the other of said elements, and resilient means cooperating with each of said cams to bias said cams toward each other and into engagement with said cam follower.

References Cited in the file of this patent UNITED STATES PATENTS France Nov. 28, 1923

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