US2380820A - Railway switch operating apparatus - Google Patents

Description

July 31,1945. H L BO E 2,380,820

RAILWAY SWITCH OPERATING APPARATUS Filed March. 18, 1944 3 Sheets-Sheet 1 IN VENTOR HPbPft Z. 50179.

W BY

Hf!" ATTORNEY A July 31 1945. H. 1.. BONE 4 RAILWAY SWITCH OPERATING APPARATUS Filed March 18 1944 s Sheet s-Sheet 2 I 5 57d 52 "Eg INVENTOR v Z' Pberf Z. 5012?. 6L1

Hf) ATTORNE Y July 31, 1945. H, ONE 2,380,820

RAILWAY SWITCH OPERATING APPARATUS Filed March 18, 1944 '5 Sheets-Sheet 3 IN VEN TOR BY 421M HLP ATTORNEY Patented July 31, 1945 UNITED STATES PATENT OFFlCE 2,380,820 RAILWAY swrrcn OPERATING APPARATUS Herbert L. Bone, Forest Hills, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa", a corporation of Pennsylvania Application March 18, 1944, Serial No. 527,041

6 Claims. (Cl. 246-290) My invention relates to railway switch operating apparatus, and particularly to apparatus for operating spring switches equipped with a facing point lock the locking plunger of which is biased to a locking position in which it locks the switch points in their normal set positions and is arranged to be automatically operated to an un- 7 locking position to unlock the switch when a train trails the switch through the medium of lock releasing linkage mechanically actuated by the train.

One object of my invention is the provision in apparatus of the type described-of novel means for moving the locking plunger of the lock to its unlocking position when a train trails the switch.

Another object of my invention is to so construct the lock releasing linkage in apparatus of the type described that the locking plunger of the lock when it is once moved to itsunlocking position by a trailing train will be held steady in its unlocking position until it is subsequently restored to its locking position to reduce wear on the parts.

Another object of my invention is to provide a novel crank stand forming part of the lock releasing linkage, which stand is effective upon a predetermined initial movement of the switch points away from their initially set position by a trailing train to move the locking plunger of the lock to its unlocking position, and to thereafter prevent any further movement of the locking plunger during the remainder of the trailing movement, and also to prevent the transmission to the switch points after they become unlocked of any force due to the spring means which biases the locking plunger to its locking position.

According to my invention, I replace the bell crank which is commonly employed in the lock releasing linkage of one well-known form of facing point lock of the type described with a cam crank stand employing a roller attached to an operating rod responsive to the displacement of the switch points from their normal set positions and cooperating with a cam crank operatively connected with the locking plunger of the lock. The cam crank is provided on both sides with cam surfaceaand is so constructed that it can be assembled in the stand in either of two positions in one of which the roller will cooperate with the cam surfaces on one side of the crank and in the other of which the roller will cooperate with the cam surfaces on the other side of the crank. The crank stand is also so constructed that it can be mounted with either side up. The ability to reverse the cam crank 01' the crank stand coupled with the ability to mount the crank stand with either side up enables the stand to be used on either side of the switch regardless of whether the switch point nearest the stand is normally open or normally closed. The cam surfaces are so constructed and the parts are so proportioned that when a train starts to trail the switch, a predetermined initial movement of the operating rod will cause the roller to cooperate with the cam crank to rotate it far enough to unlock the switch, but that any further movement of the operating rod will not produce any further movement of the locking plunger. Furthermore, the parts are so proportioned that when the locking plunger is once moved to its unlocking position, the stand will act to effectively prevent any force due to the biasing means for the locking plunger from being transmitted to the movable switch rails until these switch rails have been restored to substantially their initially set positions.

' Other objects and characteristic features of my invention will become apparent as the description proceeds.

I shall describe one form of apparatus embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a top plan view showing a spring switch controlled by a switch operating mechanism including a facing point lock the locking plunger of which is operatively connected with the movable points of the switch through the medium of lock releasing linkage embodying my invention. Fig. 2 is a top plan view on an enlarged scale of a cam crank "stand constructed in accordance with my inven- I and la are laid on tie plates 3 and are secured to crossties 4 in the usual manner. 'The movable rails 2 and 2a are fastened together by a front rod 5, a head rod 6, a bridle rod I and a tie rod 8, and may be moved into a normal or a reverse position by means of a switch operating mechanism B which is connected with the head rod 6 through the medium of an operating rod 9 and a springconnecting rod 0. When the switch occupies its normal position in which position it is shown in Fig. 1, the movable rail 2 engages the fixed rail I, and the movable rail 2a is spaced from the fixed rail la. When the switch is reversed, however, the movable rail 2a then engages the flxed rail la and the movable rail 2 is spaced from the fixed rail I.

The spring connecting rod ,0 may be of any suitable type, but in the well-known form here illustrated, this connecting rod is similar in all respects to the spring connecting rod C shown and described in Letters Patent of the United States No. 1,976,827, granted to me onOctober 16, 1934,, for Railway switch operating apparatus. It is believed, therefore, that for purposes of my present disclosure it is suilicient to point out that this connecting rod includes spring means which biases the switch points to whichever extreme position they are moved to by the mechanism B with suflicient force to permit facing point moves over the switch without displacement of the points, but which yields when a train trails the switch and thereby allows the train to force the switch points to a position opposite to that to which they are biased by the spring means.

The head rod 6 is also connected by means of an adjustable link IS with the piston rod iii of a bufiing device D. This bufiing device may also be of any suitable type but, as here shown, this bufling device is similar in all respects to the bufling device shown and described in Letters Patent of the United States No. 1,869,604, granted to William C. McWhirter on August 2, 1932, for Buffing devices for railway switches and the like. It is believed, therefore, that a detail description of this device is unnecessary. It should be pointed out, however, that this bufiing device includes, in addition to the piston rod IS, a cam shaft i1 extending into the case of the device and controlling a valve mechanism not shown. Attached to the outer end of the cam shaft I1 is a crank l8 which is connected by a link I! with the spring rod I4 of the spring connecting rod C. If when the movable rails 2 and 2a of the switch A are in their normal positions, as shown in Fig. Q

1, they are moved to their reverse positions by the a mechanism B, the piston rod l6 will be moved into the device and the cam shaft |l will be rotated in a clockwise direction, as viewed from the left in Fig. 1. The construction of the device is such that, under these conditions, the piston rod IE will be permitted to move with substantially no resistance, and the bufllng device will therefore exert practically no retarding action on the movable rails. Conversely, if the mo ble rails are moved from their reverse positions to The switch operating member B is mounted on one end of a tie strap 20 which is secured to the ties adjacent the outer side of the rail l, and as here shown is similar in all respects to that described and claimed in Letters Patent of the United States No. 2,235,031, granted to Kenneth J. J. McGowan on March 18, 1941, for Railway switch operating apparatus. Since the construction of the mechanism is described in detail in the said McGowan patent, it is believed to be suflicient for the purpose of my present application to point out that this mechanism includes a hand throw lever 2| connected with a switch operating crank 22 through suitable operating mechanism not shown in such manner that the operating crank will occupy the normal extreme position shown or will be rotated from this position in a counterclockwise direction to a reverse extreme position according as the hand throw lever occupies the position shown or its opposite extreme position. The switch. operating crank 22 is operatively connected with the previously described operating rod 9.

The mechanism B also includes a locking plunger 23 which cooperates with a notch 24 in a lock rod L to at times lock the switch in its normal position for facing point moves over the switch. when the hand throw lever 2| occupies the position shown, the locking plunger is yieldably biased by spring means 25 to a locking position in which it is disposed in the notch 24 in the lock rod L, and under these conditions the switch is locked: but when the hand throw lever is rotated from the position shown toward the opposite extreme position, the locking plunger is withdrawn from the notch 24 to unlock the switch before any movement of the switch operating crank 22 takes place.

The lock rod L is slidably mounted in suitable guideways formed in the casing of the mechanism B, and is adiustably secured at one end to the -front rod 8 of the switch A. The notch 24 is so disposed that-it will align with the locking plunger 23 when and only when the switch A occupies the extreme position in which it is shown in the drawings and the movable rail 2 is in proper engagementwith the fixed rail I.

The parts of the mechanism B are so proportioned that when the hand throw lever 2| occupies its normal position as shown, the spring means 28 which moves the locking plunger 23 to its locking position will tend to drive the locking eir normal positions by the mechanism B, the piston rod It will be moved outwardly and the cam shaft I! will be rotated in a counterclockwise direction,

7 as viewed from the left in Fig. 1, but due to the construction of the device, no retarding action will,again take lplace. If, however, when the movable rails are in either extreme position, a

train trails the switch, the cam shaft II will remain stationary, and under these conditions, the action of the device is such that the movement of the movable rails away from the positions which they previouslyoccupied will be unresisted by the bumng device, but that, when the plunger beyond the desired locking position. The locking plungenis prevented from moving beyond the desired locking position under these conditions, however, by linkage which connects it with the tie rod 8. As here shown, this linkage includes a plunger bolt 20, a turnbuckle 21, a link 28, a cam crank stand 08 embodying my present invention, and an operating rod 28.

The plunger bolt 26 is operatively connected with the locking plunger 22 by means which is movable rails are being restored to the positions which they previously occupied by the spring not shown, but which is similar to that described in detail in the aforementioned McGowan Patent No. 2,235,031, this means being such that when the locking plunger occupies its locking position, movement of. the plunger bolt 26 upwardly will cause corresponding ,movement of the locking plunger, but that the locking plunger is free to move to its unlocking position in response to operation of the hand lever 2| independently of any movement of the plunger bolt. The plunger bolt is adiustably connected at its outer end with the link 28 by means of the turnbuckle 20, as will be obvious from an inspection of Fig. 1.

The cam crank stand CS embodying my invention is shown in detail in Figs. 2, 3 and 4. As there illustrated, this crank stand comprises a cam crank 39 pivotally connected at oneend with the link 28, and pivotally mounted at the other end on a pivot pin 30 mounted in a crank stand casting3l'. The crank stand casting 3| is made substantially symmetrical about the transverse horizontal plane passing through the center of the casting so that it can be mounted with either side up for apurpose which will appear hereinafter, and it is provided with three mounting holes 32, 33 and 34 for the reception of suitable mounting bolts or otherequivalent fastening devices. The casting may be secured to any suitable supporting means, but as shown it is secured to a plate 35 which, in turn, is attached to a gage plate 3a and to the tie strap 20 upon which the mechanism B is mounted, whereby any loss of adjustment between the parts due to creepage of the ties is prevented. The end of the cam crank 39 which is pivotally mounted on the pivot pin 30 is provided with a bushing 36 (see Fig. 4) to reduce friction and wear, and the other end is provided with a bushing 3'! (see Fig. 3) for a prevent the pin from turning. The pin 30 is secured in place in the crank stand by a cotter 32 to facilitate the ready removal of the pin for a purpose which will appear presently.

The cam crank is slidably supported adjacent its free end between guiding surfaces 3 la and 3|b, and has its fre'eend disposed opposite an opening 3|c in the side wall of the casting 3| through which opening the link 28 extends into the casting 3| with considerable clearance. The pin 33 which connects the-rod 28 with the cam crank is secured in place by a cotter key 38 so that it is readilyremovable, and it is provided in one end with a lubricating fitting 49. Access to the pin may be had through aligned holes 3|d provided in the casting 3| opposite the ends of the pin 33. These holes are made sufficiently large to enable the pin 33 to be readily assembled in link 28 with the crank 39 inside the casting 3 I.

Formed in the crank stand casting 3| at one side of the pivot pin 30 is an opening 3|e through which the previously mentioned operating rod 29 extends into the casting 3|. This rod is secured at one end to tie rod 8 by means of a standard switch basket 45, and is provided at the end which extends into the casting with a jaw 29a which. receives a pivot pin 44, The pivot pin 44 carries three rollers, two of which 46 and 4'! are disposed on the pivot pin on opposite sides of the jaw prongs, and the third one of which-48 is disposed on the pivot pin between the jaw prongs. The rollers 46 and 41 cooperate respectively with vertically aligned guideways 3 and3 lg provided in the casting 3| to support the jaw 29 for longitudinal sliding movement within the casting 3| in the verticalposition in which the roller 48 is in lateral alignment with the cam crank 39, while the roller 48 cooperates with cam surfaces formed On the contiguousedge of the cam crank. The cam crank is so constructed that it can be assembled in the crank stand casting with either edge contiguous to the roller 48 to enable it to be used witheither a closed or an open point layout, as will be explained more fully hereinafter, and to this end, the two cam surfaces 39a and 39b which are formed on one edge of the cam crank are dif-- ferently shaped from the cam surfaces 390 and 39d formed on the other edge of the crank. The rollers 46, 41 and 48 are arranged to be lubricated by a lubricating fitting 42' disposed in one end of the pivot pin 44, and pairs of aligned holes 3 I7 and 3 k are provided in the casting 3| to provide access to this fitting. These holes are also used as indices for positioning the rollers 46, 4! and 48 in their correct relation to the cam crank 39, as will subsequently be made clear. The upper ones of the holes 3|a' and 3|Ic may be closed by a plate 50 secured in place by a stud 5|;

The plunger bolt 23, turnbuckle 21, link 28, cam crank 39, roller 48, operating rod 29, switch basket 45 and tie rod 3 all constitute means for unlocking the switch during a trailing move, as will be made clear presently.

The switch layout shown in Fig. 1 is a righthand layout in which the right-hand point is normally closed, and for this type of layout the cam crank 39- of the crank stand CS is assembled so that the cam faces 39a and 3% are in position to cooperate with the roller 48. Furthermore, the operating rod 29 is so adjusted that when the switch points are in their normally closed positions, the pivot pin 33 will align axially with the holes 3|d in the cam crank stand casting 3|, This places the roller 48 in the proper position with respect to cam face 39a. to insure the correct amount of stroke of the locking plunger of the switch operating mechanism. This adjustment also places pivot pin 44 in approximate alignment with holes 3H for this type of layout, thus placing lubricating fitting 42 where it is accessible. The remainder of the linkage is so adjusted by means of turnbuckle 21 that when the switch occupies its normal position the locking plunger will occupy the desired locking position Within the notch 23 in the lock rod L.

The operation of the apparatus as a whole is as follows: As was pointed out hereinbefore, when the hand throw lever 2i is rotated to its normal extreme position in which it is shown in the drawings, the switch operating crank 22 will be rotated to its normal extreme position, and under these conditions a force is exerted on the movable rails 2 and 2a of the switch throughthe medium of the spring connecting rod C, which force yield ably holds the movable rails in their normal extreme positions in which they are shown in Fig. 1. When the movable rails are in their normal extreme positions, the notch 24 in the lock rod L aligns with the lock bar 33, and the lock bar 23 is therefore free to move, due to the bias of the spring means 25, to its locking position.

When it is desired to reverse the switch, the hand throw lever 2| is rotated from the extreme position shown to its opposite extreme position.

This movement of the lever first withdraws thelocking plunger 23 from the notch 24 in the lock rod L to unlock the switch, and then moves the switch operating crank 22 from the extreme po sition shown to its opposite or reverse extreme position. The movement of the switch operating crank 22 to its reverse extreme position acts through the spring connecting rod C to exert a force on the switch rails which moves them to and yieldably holds them in their reverse positions. It should be pointed out that as long as the movable rails remain fixed, the roller 48 remains stationary, but the biasing force of the spring means 25 acting to hold the cam face 39a of the cam crank against the roller will be removed by the action of the mechanism B when the latter has been operated a slight distance from its normal position. The action of mechanism B will merely remove the spring loading but will not force. the cam crank away from the roller. Pad 55 limits the travel of the cam crank under this unloaded condition. As soon as the movable rails start to move, the resultant movement of the operating rod 29. will act through the roller 48 and cam surface 390. to rotate the cam crank 39 in a counterclockwise.direction, and this rotation, in turn, will act through the link 28 and turnbuckle 21 to move the plunger bolt in the direction that the locking plunger was previously moved so that the plunger bolt will eventually assume the same relative position with respect to the locking plunger that it occupied at the beginning of the operation of theswitch operating mechanism.

In order to restore the movable rails to their normal positions after they have been reversed as above described, the hand throw lever 21 is restored to the position in which it is shown in Fig. 1. The subsequent movements of the parts under these conditions are just the reverse of those described above, and it is believed, therefore, that the operation of the apparatus under these conditions will be readily understood from an inspection of the drawings without further description.

I shall now assume that the parts are in their normal .positions as shown in the drawings, and that a train trails the switch. As the leading wheels of the train roll along the fixed rail I and the movable rail 2a, the movable rails are forced over laterally, but before a sufficient force is developed to overcome the opposing force of the spring connecting rod C and cause the point of the movable rail 2 to move out of engagement with the fixed rail 1, the movable rails being somewhat resilient become bent, and thuscause the tie rod 8 to move toward the left, as viewed in Fig. 1. This movement of the tie rod causes a corresponding movement of the operating rod 29, and as a result, roller 48 cooperates with the cam face 39a of cam crank 39 to rotate the cam crank in a counterclockwise direction as viewed in Fig. 1. The parts are so proportioned that this initial portion of the stroke of the operating rod 29 will rotate the cam crank 39 far enough to completely withdraw the looking plunger 23 from the notch 24 in the lock rod L, and it will be apparent, therefore, that when the leading wheels of the train have reached the positions in which a sufiicient force is developed to cause the point of the movable rail 2 to move out of engagement with the fixed rail I, the switch points will be unlocked, and the points will therefore be forced open by the wheels in exactly the same manner as would be the case if no point lock were provided, and the bufiing device D will perform its normal function of preventing the movable rails from snapping back after the passage of each wheel through them. The parts are further so proportioned that upon the completion of the initial portion of the stroke of the operating. rod 28, the roller 48 will have moved into engagement with the cam face 3%, and that this cam face will then be parallel to the path of movement of the roller 48. It will be seen, therefore, that after the switch once becomes unlocked, any further movement of the operating rod will not produce any further rotation of the cam crank 39. Consequently, any oscillation of the operating rod resulting from the passage of' successive wheels or trucks of the train will be absorbed in the crank stand, and wear on the locking plunger and associated parts of the switch operating mechanism will therefore be materially reduced. Moreover, the crank stand CS will act to efiectively'prevent the transmission to the switch points after they have once become unlocked of any force due to the spring means which biases the locking plunger to its locking position. When the train which is trailing the switch has completely passed the switch, the movable rails will slowly return to their normal positions under the bias of the spring connecting rod C, and against the retarding force of the builing device D. During this return movement of the movable rails, there will be no deflection of the rails, and the roller 48 will move out of engagement with the cam face 3% and into engagement with the cam face 39a beforethe movable rails reach their full normal positions in which the lock rod is in the proper position for the notch 24 to receive the locking plunger 23. As soon as the roller 48 moves into engagement with the cam face 39a, the spring 25 which biases the locking plunger to its locking position will again become efiective to assist the spring of the spring connecting rod in restoring the movable rails to their originaltpositions, and will also act to cause the locking plunger 23 to. move into engagement with the side of the lock rod until the notch 24 moves into alignment with the lock rod. When this happens, the energy stored in the spring means 25 will force the locking plunger into the notch, and will thus restore the switch to its normal locked .position. i If the notch 24 in the lock rod should not come into alignment with the locking plunger, a suitable indication of this fact will be given by indication means forming no part of my present invention, and therefore not shown in the drawings.

As was pointed out hereinbefore, the switch layout shown in Fig. l is a right-hand layout with the right-hand switch point normally closed. When it is desired to apply the switch operating mechanism to a right-hand layout with the righthand point normally open, this can be done by assembling the cam crank 39 in the cam crank stand with the cam faces 38c and 39d'adjacent to the roller 48, as shown in Fig. 5, and. by readjust.- ing the operating rod 29 relative to the switch basket 45 so that when the switch points are, in their normally closed positions, the pin 33 will align with the holes 31d in the crank stand casting 3|. This adjustment places pivot pin 44 in approximate alignment with hole 3170 for this type of layout.

With the parts arranged as shown in Fig. 5 when a train trails the switch, the switch operating rod 29 is pushed to the right so thatroller 48 operates the 'cam crank 39 by pushing against cam surface 39c. Theoperation of the cam crank in this manner acts through the link '28, turnbuckle 21 and plunger bolt 26 to move the looking plunger to its unlocking position, and also causes the cam faces 39d to assume a position in which it is parallel to the path of movement of the roller 48. Upon the completion of the unlocking stroke of the locking plunger, the roller 48 is in engagement with the cam face 39d, and since it is then parallel with the path of movement of'the roller, no further rotation of the cam crank takes place and the locking plunger thereupon remains stationary until the train has completed its trailing movement and the switch points have returned to Withina relatively short distance of their normally closed. positions. It follows, therefore, that the operation of the apparatus when the cam crank is assembled as shown in Fig.5 is essentially the same as when it is assembled as shown in Fig. 1.

When it is desired to apply the switch operating mechanism B to a left-hand switch layout with the left-hand point normally closed, the crank is assembled in the crank stand with the cam faces 39a and 39b adjacent to the roller 48, as showninFigs. 2, 3 and 4,,but the crank stand is secured to the gage plate with the side of the crank stand casting which is the upper side in Fig. 1 as the lower side, as shown in Fig. 6. Likewise, when it is desired to apply the switch operating mechanism B to a left-hand layout with the right-hand point normally closed, the crank is assembled in the crank stand in the position in which the faces 39c and 39d are adjacent to the roller 48, but the crank stand is turned now from the position shown in Fig. 5, as is illustrated in Fig. 7. The operation of the apparatus as a whole with either of these latter assemblies will be apparent from the foregoing and from an inspection of the drawings without further detail description.

It will be seen from the foregoing that for closed point layouts cam crank 39 is assembled so that the roller 48 will cooperate with the cam faces 39a. and 3%, whereas for open point layouts the cam crank is assembled so that the roller 48 will cooperate with the cam faces 39d and 39e. Furthermore, for closed point layouts the operating rod. 29 is adjusted so that roller 48 aligns axially with the holes 3l7 when the switch points are in their normally closed positions, but for open point layouts the operating rod 29 is adjusted so that roller 48 will align axially with the holes 3l7c when the switches are in their normally closed positions.

It should also be pointed out that a cam crank stand constructed in accordance with my invention besides eliminating oscillation of the locking plunger while a train is trailing the switch, acts to reduce the plunger motion associated with the slight motion of the switch rails which occurs under traffic passing on the switch lead when the switch is in its normal position. The bell crank which was heretofore used in place of the cam crank 39 and roller 48 to transmit motion from the tie rod 8 to the locking plunger to unlock the switch usually had either a 2 to 1 or a 1 /2 to 1 ratio of plunger'travel to tie rod travel, and these ratios were necessarily in eiIect in all plunger positions. The cam crank 39 of my crank stand CS, however, is so proportioned that it gives a ratio of plunger travel to tie rod travel which varies through the plunger stroke. While in actual practice the ratio of the plunger travel to the rod travel with the cam crank averages 1% to l. in withdrawing the locking plunger from its locking position the maximum amount necessary to clear the lock rod, this ratio is only about 1%; to 1 when the switch points approach their normally closed positions.

Thus A of lateral ,motion of the tie rod 8 undertraffic passing over the normally closed point would heretofore have produced A; or T33", motion of the plunger when a bell crank lever is used in place of the cam crank stand. With the cam crank lever stand this same motion of the normally closed point will produce only motion. This is important due to the resultant reduction in wear of the parts and in providing improved operation of the parts generally. I

Although I have herein shown and described spirit and scope of my invention.

Having thus described my invention, what I claim is:v

1. In combination with a spring switch biased by spring means to a set position, locking mechanism for locking the switch in its set positions comprising a locking plunger biased to a locking position, and means for actuating said plunger to an unlocking position when a train trails the switch comprising'a cam crank stand, a cam crank pivotally supported in said stand and operatively connected with said locking plunger, and an operating rod actuated by a trailing train and provided with a roller cooperating with cam surfaces provided on said cam crank, said cam crank being provided with two separate sets of cam surfaces and being capable of being assembled in said stand in two positions in one of which the one set of cam surfaces cooperates with said roller and in the other of which the other set of surfaces cooperates with said roller, the one set of cam surfaces being adapted to provide theproper movement of said crank to move the locking plunger to its unlocking position when said stand is mounted on the normally open point side of said switch and the other set of cam surfaces being adapted to provide the proper movement of said crank to move the locking plunger to its unlocking position when said stand is mounted on the normally closed point side of said switch.

2. In combination with a spring switch biased by spring means to a set position, locking mechanism for locking the switch in its set position comprising a locking plunger biased to a looking position, and means for actuating said plunger to an unlocking position when a train trails the switch comprising a cam crank stand adapted to be mounted on either side of said switch and constructed to be disposed with one face 'down when mounted on one side of said switch and with the other face down when mounted on the other side of said switch, a cam crank pivotally mounted in said crank stand and operatively connected with said locking plunger, said cam crank being capable of being assembled in said stand in either one of two positions and being provided with two cam faces, and an operating rod actuated by a trailing train and provided with means cooperating with one cam face or the other to actuate said crank in response to actuation of said rod according as said crank is assembled in said stand in the one or the other of said two positions, the one said cam face being adapted to provide the proper movement of said crank to move the locking plunger to its unlocking position when said stand is mounted on the normally open point side of the switch and the other said cam face being adapted to provide the proper movement of said crank to move the locking plunger to its unlocking position when said stand is mounted on the normally closed point side of the switch.

3. In combination with a spring switch biased by spring means to a set position, locking mechanism for locking the switch in its set position comprising a locking plunger biased to a lockin position, and means for actuating said plunger to an unlocking position when a train trails the switch comprising a cam crank stand; a cam crank pivotally supported in said stand and operatively connected with said locking plunger, and an operating rod actuated by a trailing train and provided with a roller cooperating with cam surfaces provided on said cam crank, said cam crank being provided with two cam surfaces and being capable of being assembled in said stand in two positions in one of which the one cam surface cooperates with said roller and in the other of which the other cam surface cooperates with said roller, the one cam surface being adapted to provide the proper movement of said crank to move the locking plunger to its unlocking position when said stand is mounted in the normally open point side of said switch and the other cam surface being adapted to provide the proper movement of said crank to move the locking plunger to its unlocking position when said stand is mount- M ed in the normally closed point side of the switch.

4. In combination with a spring switch biased by spring means to a set position, locking mechanism for locking the switch in its set position comprising a locking plunger biased to a locking position, and means for actuating said plunger to an unlocking position when a train trails the switch comprising a tie rod connected with the movable rails of said switch intermediate the heel and the toe of the switch, a cam crank stand adapted to be mounted on either side of said switch and constructed to be disposed with one face down when mounted on one side of said switch and with the other face down when mounted on the other side of said switch, a cam crank pivotally mounted in said crank stand and operatively connected with said locking plunger, said cam crank being capable of being assembled in said stand in either one of two positions and being provided with two cam faces, and an operating rod adjustably connected atone end with said tie rod and provided at the other end with a roller guided in said stand in a position for'said roller to cooperate with one cam face or the other to actuate said crank in response to actuation of said operating rod according as said crank is assembled in said stand inthe one or the other of said two positions, the one said cam face being adapted to provide the proper movement of said crank to move the locking plunger to its unlocking position when said stand is mounted on the normally openpoint side of the switch and the-other said cam face being adapt-- ed to provide the proper movement ofsaid crank Y heel andthe toe of the switch, a cam crank stand adapted to be mounted on either side of said switch and constructed to be disposed with one face down when mounted on one side of said switch and with the other face down when mounted on the other side of said switch, a cam crank pivotally mounted in said crank stand and. operatively connected with said locking plunger, said cam crank being capable of being assembled in said stand in either one of two positions and being provided with two cam faces, and an operating rod adjustably connected at one end with said tie'rod and provided at the other end with a roller guided insaid'stand in a position for'said roller to cooperate with one cam face or the other to actuate said crank in response-to actuation of'said operating: rod according as said crank is assembled in said standin the one or the other of said two positions, the one said cam face being adapted to provide the proper movement of said crank to move the locking plunger to its unlockingposition when said stand is mounted on the normally open point side of the switch and the other said cam face being-adapted to provide the proper movement of said crank to move the locking plunger tov its unlocking position when said stand is mounted on the normally closed point side of the switch, and holes in said stand acting as indices. for positioning said roller relative to said cam crank by' adjustment of said: operating rod relative to saidtie rod' when the switch points arein their normal positions.

6; A camcrank stand for actuating afirst rod in response to actuation of' a second rod, said stand comprising a casting, a cam crank pivoted at one end on a first pivot pin mounted in said casting and pivotally connected at its other end with said first rod, guides in said casting adjacent one side of said crank, rollers journaled on a second pivot pin mounted in one end of said second rod and cooperating'with said guides to guide said one end of said second rod for longitudinal sliding movement, another" roller pivoted on said second pivot pin and; cooperating with camsurfaces provided on the contiguous edge of'saidcam crank, said cam'crank being capable of'being' assembled on said first pivot pin with either edge contiguous to said roller and being provided with cam surfaces on each edge, the cam surfaces on one edge being adapted when in position to cooperate with said other roller to produce a predetermined rotation of said crank in response to a predetermined initial movement of said second rod in one direction and to permit additional movement of said second rod. in said one direction without causing additional movement of said crank, and the cam surfaces on the other edge being adapted when in position to cooperate with said other roller to produce a predetermined rotation of said crank in response to a predetermined initial movement of said second rod in the. other direction and to permit additional movement of said second: rod in said other direction without causing additional movement of said crank.

HERBERT L. BONE.

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