US2007674A - Railway switch operating apparatus - Google Patents

Description

July 9, 1935.

H. L. BONE RAILWAY SWITCH OPERATING APPARATUS Filed Nov. 1, 1935 INVENTOR HQPbQPt L.B0ne BY QJZQZYMMLZ HIS A TTORNEY July 9, 1935. H. L, BONE RAILWAY SWITCH OPERATING APPARATUS Filed NOV. 1, 1935 I) Sheets-Sheet 2 July 9, 1935. -H. BONE RAILWAY SWITCH OPERATING APPARATUS Filed Nov. 1,

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RAILWAY SWITCH OPERATING APPARATUS Herbert L. Bone, Pittsburgh, Pa, assignor to The Union Switch & Pa, a corporation Signal Gompany, Swissvale, oi Pennsylvania Application November 1, 1935, Serial No. 696,208 14 Claims. (Cl. 2445-291) My invention relatesto railway switch operating apparatus, and particularly to apparatus for operating railway switches which are intended H to be trailed at times;

' One object of my invention is to provide apparatus of the type described wherein a standard switch operating and locking device is controlled jointly by manually operablemeans and by means connected with the switch points in such manner that the device is normally biased to a selected extreme position in which the switch points are locked in a corresponding extreme position, but that, when a train trails the switch, the device is then mechanically operated by the train to a position to unlock and reverse the switch points, before suincient force is exerted on the points to damage the points or the switch operating device, and is subsequently held in such latter position until after the train is completely past the switch, at which time the switch operating device is restored to its original position by the biasing means.

I will describe two forms of apparatus embcdying my invention, and will then point out the novel features thereof inclaims.

In the accompanying drawings, Fig. 1 is a top plan view showing one form of apparatus embodying my invention. Fig. 2 is an enlarged side View, partly sectioned, of the switch operating mechanism B shown in Fig. 1. Fig. 3 is an enlarged. vertical sectional view of the combined biasing and bufiing device D shown in Fig. 1. Fig. l is a fragmentary sectional view of the device D shown in Fig. 8 taken on a plane parallel to, and spaced from, the plane of Fig. 3. Fig. 5 is a top plan view showing a modified form of the apparatus illustrated in Fig. l and also embodying my invention. Fig. 6 is an enlarged vertical sectional view of the device Di forming part of the apparatus illustrated in Fig. 5.

Similar reference characters refer to similar parts in each of the several views.

Referring first to Fig. 1, the reference character A designates a railway switch comprising, as

usual, two fixed rails i and l and two movable rails 2 and 2 The fixed rails I and l are laid on tie plates 3 and are secured to crossties 5 in the usual manner. The movable rails 2 and 2 are fastened together by a front rod 5, a head rod 6, a bridle rod 3, 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 5 ma manner which I will describe hereinafter. When the 6: switch occupies its normal position in which position it is shown. in Fig. l, the movable rail 2 engages the fixed rail i, and the movable rail 2' is spaced a slight distance from the fixed rail i When the switch is reversed, however, the movable rail 2 then engages the fixed rail l and 5 th movable rail 2 is spaced from the fixed rail i The switch operating mechanism B is secured to one end of a tie strap 9 which is bolted to the ties 4 adjacent the outer side of the rail and as here shown, comprises a base plate ill upon 10 which a motion plate H is guided to move longitudinally by means of rollers 52 journaled on studs 63 which project upwardly from the base plate. The motion plate is adapted to be recipro cated between two extreme positions in a manner 15 which I will describe hereinafter, and has formed therein a cam slot it having a portion at each end which is parallel to the direction of movement of the motion plate and an intermediate i connecting portion which is disposed at an angle 20 to the direction of movement of the motion plate. Extending into the cam slot i l and cooperating therewith is a roller is mounted on a pin It secured to a throw bar 57. The throw bar H extends transversely of the motion plate, and is guided to movelongitudinally by means of the same rollers 92 which guide the motion plate H. One end of the throw bar ii is operatively connected with the previously described head rod 6 of the switch A.

The switch operating mechanism B also comprises a locking device 48 (see Fig. 2) which is secured to the left-hand end of the motion plate, and which in the form here shown comprises an upper bar 58 and a lower bar is riveted together in parallel spaced relation. Attached to the bars m and E3 respectively, is a normal looking dog i9 and a reverse locking dog i9 which locking dogs cooperate respectively with normal notches 20 and reverse notches 20 formed in the upper and lower edges of an adjustable lock rod L. The lock rod L is'of the usual and well-lmown construction, and is connected to the front rod 5 of the switch A in the usual manner.

The portion of the apparatus thus far described is well known and itsoperation is well understood, so that for purposes of the present disclosure the following brief description of the operation of this portion of the apparatus is believed to besuificient. When the motion plate I I occupies its extreme left-hand or normal position in which position it. is shown in the drawings, the movable rails of the switch A are securely held in their normal positions by engagement or the roller is with the right-hand end of the cam slot l4, and under these conditions, the normal locking dog lS enters the normal notches in the lock rod L and locks the movable rails in their normal positions. When, however, the motion plate is moved from its extreme normal position to its opposite extreme or reverse position, the first part of the movement of the motion plate withdraws the normal locking dog I9 from the normal notches 25 in the lock rod L, the intermediate part of the movement of the motion plate causes the switch points to be moved to their reverse extreme positions, and the final part of the movement of the motion plate moves the reverse locking dog 5% into engag ment with the reverse notches 23 in the lock rod L to lock the movable rails in their reverse positions. The operation of the apparatus when the motion plate is subsequently restored to its extreme normal position is exactly the reverse of that just described, and will be obvious from an inspection of the drawings.

The motion plate H is operatively connected by means of a turnbuckle 2| and a link 22 with the long arm 23 of a bell crank lever 23. The bell crank lever 23 is pivotally supported in a crank stand 24, and has its short arm 23 pivotally connected with the piston rod 28 of a combined biasing and buiiing device D. The short arm 23 of the bell crank lever is also operatively connected with one end of an operating rod 25, the other end of which is operatively connected, by means of nuts 25 and 25 and a standard switch basket 21, with the previously referred to tie rod 8. A certain amount of clearance is provided between the nuts 25 and 25 and the switch basket 21 for reasons which will be made clear hereinafter.

The tie rod 8 may be located at any suitable location, but will preferably be located approximately halfway between the heel and the point of the switch. The base 24 of the crank stand 24 is secured to a base plate 82 which base plate, in turn, is secured to the previously described tie strap 9. It will be apparent, therefore, that any loss of adjustment between the parts due to creepage of the ties is prevented.

The combined biasing and buffing device D may be of any suitable type but in the form illustrated in Figs. 3 and 4, this device comprises a suitable casing 29 provided in the lower part thereof with two axially aligned cylinders 39 and 3B. These cylinders are closed at their outer ends by cylinder heads Bi and 3t and communicate at their inner ends with an axially aligned cylindrical chamber 32 having a some what larger diameter than the cylinders 3E3 and The piston rod 28 extends into the cylinders 30 and through a stufling box 33 and through a suitable opening 34 in the cylinder head 3 l and has attached thereto two pistons 35 and 35 which are adapted to reciprocate in the two cylinders 30 and 39 respectively. The pistons 35 and 35 are attached to the piston rod 28 in such positions that when the piston 35 is in the center of the cylinder 39 the piston 35 will be in the center of the cylinder 35 The cylinders 3& and 30 and the chamber 3?. are intended to be filled with a suitable fluid, such as oil, and the stufling box 33 forms a fluid type joint through which the piston rod may slide.

Surrounding the piston rod 28 between the two pistons 35 and 35 is a compressed coil spring 31. One end of this spring abuts against an inwardly extending annular flange 38 forming part of a spring socket 39 which is slidably mounted in the inner end of the cylinder 3%, and the other end of this spring abuts against an inwardly extending annular flange 38 forming part of a spring socket 39 which is slidably mounted in the inner end of the cylinder 38 The end of the spring socket 39 opposite to the inwardly extending annular flange 38*- is provided with an outwardly extending annular flange till which cooperates with a shoulder M formed at the junction of the cylinder 3% and the chamber 32, and the end of the spring socket 39 opposite to the inwardly extending annular flange 38 is likewise provided with an outwardly extending annular flange 4i) which cooperates with a shoulder 41 formed at the junction of the cylinder 30 and the chamber 32. A certain amount of clearance is provided between the flanges 38 and 38 and the piston rod 28 and also between the flanges and 40 and the chamber 3-2, and the parts are so proportioned that when the pistons 35 and 35 are in the centers of the associated cylinders 30 and 33 if the flanges 4 I and 4 I are then engaging the shoulders 40 and 40 respectively, the flanges 38 and 38' will be engaging the adjacent pistons 35 and 35 It will be apparent, therefore, that the spring 31 constantly biases the piston rod 28 to its mid stroke position in which the pistons 35 and 35 are in the centers of the associated cylinders.

The cylinder wall of the cylinder 30 is provided at its right-hand end with a leak groove 35 and the cylinder wall of the cylinder 30 is similarly provided at its left-hand end with a leak groove 35*. The function of these leak grooves is to permit fluid to flow past the pistons under certain conditions which will be made clear hereinafter.

The upper part of the casing 29 has formed therein a reservoir 42 which is also intended to be filled with fluid. The cylindrical chamber 32 is constantly connected at or near its center with this reservoir by means of an opening 43 formed in the upper part of the chamber wall. As best seen in Fig. 3, the left-hand end of the cylinder 39 is also connected with the reservoir 42 through a port 44, a regulating valve 45, and two ports 45 and 41. The regulating valve 45 may have any suitable form, but in the form here shown, this valve is similar in all respects to that described in Letters Patent of the United States No. 1,869,604, granted Aug. 2, 1932, to William C. McWhirter, for Bufling devices for railway switches and the like. It is believed,

therefore, that for purposes of the present disclosure, it is suflicient to state that the regulating valve 45 comprises a rotatable valve member 45 provided with a plurality of restricted orifices 45 one or more of which may be brought into registration with the port 46 by turning the valve member 45 to the proper position.

The left-hand end of the cylinder 30 is further connected with the reservoir 42 through two coaxial ports 50 and 5|, as shown in Fig. 4. The flow of fluid through these ports is controlled by a poppet valve a comprising a valve member 52, carried by a valve stem 53, and cooperating with a valve seat 54 formed in the end of the port 50. The right-hand end of the valve stem 53 is fluted and extends into the ports 50 and 5|, while the left-hand end of the valve stem 53 slides in a guide bearing 55 formed in a plug 55 screwed into a threaded opening in the cylinder head 3| A spring 51 having one end located in an annular recess 58 formed in the plug 5'! "to center the's'pring with respect to the valve,.engages the valve member 52 and constantly urges the valve member towards the valve seat 5 This spring is made sufficiently light in weight and the parts are so proportioned that the valve member 52 will move away from the valve seat 5 3, and permit fluid to flow from the reservoir 42 into the left-hand end of the cylinder 3t as soon as the pressure of the fluid in the reservoir becomes greater than that in the cylinder 3t The right-hand end of the cylinder 30 is connected with the reservoir 432 through a port 5s, a regulating valve iii, and two ports 62 and 63, and also through two coaxial ports 64 and $55. The regulating valve ti is similar in all respects to the regulating valve t5, and comprises a rotatable valve member ti provided with a plurality of restricted orifices ti one or more of which may be brought into registration with the port 672 by turning the valve member 6V to the proper position.

The flow of fluid through the ports 64 and 65 is controlled by a poppet valve b. This poppet valve is similar to the poppet valve 11, and comprises a valve member B6 carried by a valve stem 6? and cooperating with a valve seat 53 formed in the end of the port 52. The left-hand end of the valve stem 6'! is fluted and extends into the ports to and while the right-hand end of the valve 67? is mounted to slide in a guide bearing iii! formed in a plug iii. The plug it is provided with an annular recess H which receives one end of a coil spring it. The other end of the coil spring 72 engages the valve member 66 and constantly urges this valve member toward the valve seat 68. The spring i2 is made sumciently light in weight and the parts are so proportioned that the valve member 5% will unseat itself and permit fluid to flow from the reservoir 42 into the right-hand end of the cylinder 38* as soon as the pressure of the fluid in the reservoir :22 becomes greater than that in the right-hand end of the cylinder St To facilitate the insertion of fluid into the device D, a screw plug 52 is provided in the upper part of the reservoir @2, as shown in Fig. 3.

The operation of the device D, as a whole, is as follows: As shown in Figs. 3 and 4, all parts are in their normal positions; that is .to say, the valves a and b are both closed, and the piston rod 23 is held in its mid stroke position by reason of the abutment oi the spring 3? at its opposite ends against the flanges 353 and 38 of the spring sockets til and 39, the engagement of the flanges 33 and 38 with the adjacent pistons and and the engagement of the flanges and so with the shoulders di and dl respectively.

I will now assume that with the parts in their normal positions as just described, a force is exerted on the piston rod 23 which moves it from its mid stroke position in which it is shown in Figs. 3 and l, toward the right, to the right-hand end of its stroke. This movement of piston rod 28 toward the right, of course, moves the pistons 35 and 35' toward the right a like amount, and the movement of piston 35* toward the right, in turn, moves spring socket 3t toward the right. During this movement of spring socket 353* to- Ward the right, spring socket 39 is held in the position shown, due to the engagement of the flange te with the shoulder ll and as a result, spring t'i becomes compressed, and exerts an increased force on the piston rod 23, whichforce constantly tends to return the piston rod to its mid stroke position. The movement of piston 35 toward the right also causes fluid to flow from cylinder 38 on the right-hand side of piston 35 through leak groove 35 into cylinder 30 on the left-hand side of piston 35), until piston 35 passes the rightdiand'end of leak groove 35 whereupon valve opens and permits fluid to flow from cylinder 39* on the right-hand side of piston 35 through chamber 32, opening it, reservoir 52, ports 55} and hi, and valve a into cylinder to on the left-hand side of piston 3E while the movement of piston 35 toward the right causes fluid to flow from cylinder 3% on the ri ht-hand side of piston 35* through leak groove E t into cylinder on the left-hand side of piston Se The leak grooves 36 and 36" are made. relatively large so that fluid can flow through these grooves at a relatively rapid rate, and as was previously pointed out, the pressure exerted on the valve member 52 of valve a is comparatively small, so that very little pressure is required to open valve a. It will be apparent, therefore, that during movement of piston rod Fit from its mid stroke position to the right-hand of its stroke, the flLL'd in the device 13 oflers very little resistance to the movement of the piston rod, and that practically all the'resistance which is offered to the movement of the piston rod under these conditions is that which is necessary to overcome friction and to compress the spring 3?.

I will now assume that after piston rod 28 has been moved, in the manner just described, to the right-hand end of its stroke as viewed in Figs. 3 and the force which moved it there is removed, so that the piston rod is free to return to its normal or mid stroke position under the action of the spring 3'3. Under these conditions, as soon the piston rod starts to move, spring 57 closes valve 0!, thus preventing fluid from flowing past this valve, and as a result, the return movement of the piston rod is then limited to the rate at which the fluid in the cylinder 38* on the leit-hand side of piston 35 can flow through the regulating valve #35, until piston 35 has passed the right-hand end of leak groove 36 it being obvious, of course, that during the whole return movement of the piston rod, the fluid in cylinder 38 on the left-hand side of piston 35 is free to flow past piston 35 through leak groove 36 into cylinder 38* on the right-l1and side of piston 35*. The rate at which fluid can flow through the regulating valve 55 may be varied in the manner previously described, and it will be apparent, therefore, that the rate at which the piston rod 23 can return to its mid stroke position under the conditions just described may be adjusted to any desired value.

If piston rod 28 is moved to the left-hand end of its stroke from its mid stroke position, spring socket 39 will be held in the position shown, due to the engagement of flange 543 with the shoulder 4i", and spring socket 39 will be moved toward the left by piston 35 thus compressing spring 3?, and hence causing the spring to exert an increased force on the piston rod 28 tending to restore the piston rod to its mid stroke position. During the movement of the piston rod to the left, fluid in the left-hand side of cylinder 38 flows through leak groove 35 into cylinder 3t on the right-hand side of piston 35 while fluid in the left-hand side of cylinder 30 flows through leak groove 355 into cylinder Lili on the right-hand side of piston35 until piston 35 passes the left-hand end of leak groove 36 whereupon valve b opens and permits fluid to how from cylinder 30 on the left-hand side of piston 35 through chamber 32, opening 43, reservoir 42, ports 84 and 65, and valve 1) into cylinder Bfi on the right-hand side of piston 35*. It will be apparent, therefore, that during movement of the piston rod 28 to the left from its mid stroke position, thefiuid in the device offers substantially no resistance to the movement of the piston rod, and that substantially all the resistance which is offered to the movement of the piston rod is that due to spring 37.

After piston rod 28 has been moved to the lefthand end of its stroke, ii the force which moved it there is then removed, piston rod 28 will then return to its normal position under the action of spring 31 in substantially the manner as when the piston rod is moved to the right-hand end of its stroke and the force which moved it there is removed. Under these latter conditions, however, the rate of movement will be controlled by the valve 6i in a manner which will be readily understood from the foregoing description without further detailed description.

The boiling device D is slidably supported between two plates l3 and M which are secured to an adjacent pair of the ties 4, and is operaiively connected by means of a link i! with a suitable manually operable switch-throwing device here shown, for purposes of illustration, as a hand lever 15 pivotally mounted in a plate l6 secured to the same pair of ties l to which the plates i3 and M are secured.

The operation of the apparatus, as a whole, is as follows: When the hand lever '55 is rotated to its normal position in which it is shown in the drawings, the device D is moved bodily away from the track to what I shall term its normal position, and the parts are so proportioned that under these conditions a force will be exerted on the motion plate l of mechanism B through the medium of spring socket spring 32, spring socket 39 piston 35* and piston rod 28 of device D, and the linkage which connects piston rod 28 with the motion plate, which force will be sufficient to move the motion plate to, and hold it in, its normal position, except under certain conditions presently to be ribed. When, however, the hand lever 15 is rotated from its no"- mal position through an angle of substantially to its reverse position, the device I) is then moved bodily toward the track to what I shall term its 'everse position, and the parts are so proportioned that under these latter conditions, a force will then be exerted on the motion plate irough the medium of spring socket 39 spring 37, socket 3%, piston 35 and piston rod 2'8 of device D, and the linkage which connects piston rod 28 with the motion plate H, which latter force will be suflicient to move the motion plate to, and hold it in, its reverse position, except under other conditions which will be described hereinafter. As was previously pointed out, when the motion plate i is moved to its normal position, the switch A is moved to, and locked in, its normal position, and when the motion plate is moved to its reverse position, the switch A is moved to, and locked in, its reverse position. It follows, therefore, that the switch A will normally be moved to, and looked in, its normal or its reverse position, according as the hand lever i5 is moved to its normal or its reverse position. The operating rod 25 is so adjusted that when the switch A and hand throw lever 15 are both in their normal positions, the nut 25 will tightly engage the switch basket 2'! and will exert a force on the movable rails through the medium of the switch basket 21 and tie rod 8 which tends to hold the movable rails in their normal positions, but that, when the switch and hand throw lever 15 are both in their reverse positions, the nut 25 will then tightly engage the switch basket 21 and will exert a force on the movable rails through the medium of the switch basket and the tie rod 8 which latter force tends to hold the movable rails in their reverse positions. The operating rod 25 is further so adjusted that when the switch is being moved from its normal position to its reverse position, the nut 25 will not move into engagement with the switch basket until after the motion plate H has been moved away from its normal position far enough to unlock the switch, and that when the switch is being moved from its reverse to its normal position, the nut 25 will not move into engagement with the switch basket until after the motion plate has been moved away from its reverse position far enough to unlock the switch. It will be apparent, therefore, that when the hand lever is moved to either extreme position, a force will be exerted on the movable rails at the point where the tie rod 8 connects these ails, which force will aid that due to the switch operating mechanism in moving the movable rails to the extreme position corresponding to the position to which the lever 75 is moved.

I will now assume that the parts are in their normal positions as shown in Fig. 1, and that a trails the swi ch. Under these conditions, as the leading wheels of the train roll along the fixed rail l and the movable rail 2 a force is exerted on "h movable rails which tends to move tr to t reverse positions. This force is initiall resisted at the points of the rails by the engagement of the roller 15 carried by the throw bar of the switch operating mechanism B with the straight portion at the right-hand end of the cam slot i l in the motion plate I l, and also by the engagement of the locking dog l9 with the notches Ell in the lock rod L, and since the rails are somewhat resilient, this force causes the rails to become bent in such a way that the tie rod 8 moved downwardly as viewed in Fig. 1. It will be apparent that any downward movement of the tie rod 8 acts through the linkage which connects the .e rod 8 with the motion plate ll of the mechanism B to move the motion plate from its no anal position toward its reverse position an amount which depends upon the ratio of the short and long arms of the bell crank lever 23; and the parts are so proportioned that the downward movement of the tie rod 8, which occurs before the iorce exerted at the points of the movable rails tending to move them to their reverse positions has a magnitude which is anyways near the magnitude of the opposing force which the mechanism B is capable of exerting, will cause sufiicient movement of the motion plate II to withdraw the locking dog l9 from engagement with the notches 2i! in the lock rod L, and to move the roller i5 carried by the throw bar I! out of the straight portion at the right-hand end of the cam slot i i, and into the inclined central portion of the cam slot. As soon as the locking dog I9 is withdrawn from the notches 20 in the lock rod and the roller l5 enters the inclined central portion of the cam slot, the movable rails are, of course, free to move to their reverse positions, and as the leading wheels of the train continue their movement toward the points of the movable rails, the movable rails, at the positions at which they are connected by the tie rod 8, are forced to their full reverse positions. The resultant additional movement of the tie rod 8 causes the motion plate i E of the mechanism B to move toward its reverse position far enough to move the roller I out of the inclined portion of the cam slot M of the motion plate and into the straight portion at the left-hand end of thecam slot, thus forcing the movable rails to their full reverse positions at the points of these rails by means of the mecha nism B. The downward movement of the tie rod 8 caused by the trailing train, in addition to operating the mechanism B in the manner just described, also moves the piston rod 28 of the combined biasing and buffing device D downwardly, and since the casing of the device D is held stationary under these conditions due to its connection with the hand lever 15, the spring 31 .of the device D becomes compressed and exerts a relatively large force which tends to restore the movable rails to their normal positions at the position at which they are connected by the tie rod 8, and also to restore the motion plate II to its normal position. As long, however, as the train continues to trail the switch, the movable rails are held in their full reverse positions because the buffing action of the device D limits the movement of the motion plate to a relatively small amount, and since the roller I5 is then in the straight portion at the left-hand end of the cam slot is in the motion plate, a limited amount of movement of the motion plate back and forth can occur without any motion of the movable rails. It will be apparent, therefore, that with apparatus embodying my invention, the greater part of the wear on the switch points which occurs during trailing with the conventional type of spring switch is entirely eliminated. After the train has trailed completely through the switch, the spring 3'! of the device D (retarded, of course, by the bufiing action of the device) forces operating rod .25 upwardly, and motion plate H to-- ward its normal position. The initial part of the upward movement of the rod 25 causes a force to be exerted on the movable rails tending to move them toward their normal positions before motion plate 1! l is moved far enough toward its normal position to move roller l5 out of the straight portion at the left-hand end of the cam slot and into the inclined central portion of the cam slot, and it will be apparent, therefore, that the movable rails must deflect slightly before the points of these rails are released by the motion plate. After the points of the movable rails have once been released, however, the motion of the motion plate moves the movable rails to their normal position. During the last part of the movement of the movable rails to their normal position, the nut 25 moves away from the switch basket 21, this movement being made possible by the previously described clearance between the nuts 25 and 25 of the operating rod 25 and the switch basket 27. After the movable rails havereached their full reverse positions, however, the roller !5 then enters the straight portion at the righthand end of the cam slot and the clearance between the nut 25 and the switch basket is taken up and. the locking dog I9 is moved into the notches 28 in the lock rod 29. When the motion plate has been returned to its full normal position, all parts are then restored to their normal positions in which they are shown in the drawference in the relation of the parts of the apparatus when the switch is moved to its reverse position by means of the hand lever and when the switch is trailed to its reverse position, this dif ference being that when the switch is moved to its reverse position by means of the hand lever, nut 25 of operating rod 25 is in engagement with switch basket 2'3, roller I5 is moved well into the straight portion at the left-hand end of the cam slot id in the motion plate l i of the mechanism B, and the reverse locking dog 59 occupies the reverse notch 25J in the lock rod L; whereas, when the switch trailed to its reverse position, nut 25 is in engagement with switch basket 2?, roller l5 has just barely entered the straight portion at the left-hand end of the cam slot M in the motion plate ii, and the reverse locking dog is not in engagement with the corresponding notch in the lock rod.

When the switch occupies its reverse position and a train trails theswitch, the operation of the apparatus is similar to that just described, except that the movement of the various parts is reversed in direction, and it is believed, therefore, that this operation will be readily understood from an inspection of the drawings and from the foregoing description without further detailed description.

It is well-known that some switches are stiffer, and therefore more difiicult to operate than others. The force which the spring 3! in the bufiing device D can be made to exert is limited to the force which will not derail the lightest cars which are permitted to trail the switch, and when the apparatus embodying my invention is used in connection with a switch which is unusually difficult to operate, it may be necessary, in order to secure the proper operation'of the switch, to decrease the ratio of the levers 23 and 2;"! of the bell crank lever 23 to the extent that when a train trails the switch, the motion plate of the operat ing mechanism 13 will not be moved far enough to cause the roller to enter the straight portion at the end of the cam slot in the motion plate opposite to the end which it occupied before the train started to trail the switch. With the parts constructed in this manner, the movable rails of the switch will not be positively held in the extreme position to which they are moved during the trailing, but since the effect of the spring which tends to restore the rails to their movable positions is applied at the mid points of the movable rails, rather than at the forward ends of these rails as is the case in conventional spring switches, the pressure exerted at the points of the movable rails against car wheels during trailing, will be very much less than that which is exerted with the conventional type of spring switch, and the wear, therefore, on the movable rails will be much less. The reduction in pressure at the points of the movable rails is due first to the mechanics of the layout which, since the spring load which is the same as for conventional spring switches, is at the mid point rather than at the tips of the movable rails, results in the reaction at the points of the rails being one-half of the spring load, and secondly, because the points of the movable rails are free and will, therefore, bend back and thus relieve the pressure.

()ne advantage of proportioning the parts in the manner just described over proportioning them in the manner first described is that the latter proportioning causes less travel of the motion plate, and since the ratio of the armsof the bell crank lever 23 is decreaseithe force which the motion plate will exert to move the points of the movable rails to their extreme positions will be correspondingly greater for any given strength of spring in the combined biasing and bufling device D.

Referring now to Fig. 5, in the modified form of the apparatus here shown, the combined biasing and buffing device D shown in Fig. i. has been replaced by a combined biasing and buffing device DI, andthe hand throw lever shown in Fig. 1 has been replaced by a hand throw lever SI. The device DI is similar in all respects to the device D with the exception that the device DI is provided, in place of the piston rod 28 of the device D with a piston rod 28 which extendscompletely through the device (see Fig. 6), and rack teeth 83 have been formed on the easing of the device.

As shown in Fig. 5, one end of the piston rod 28*- of the device DI is operatively connected, by means of the turnbuckle 2 I, with the motion plate I i of the mechanism B, and the other end of the piston rod 28 is operatively connected, by means of a link 82, with the long arm 23 of the bell crank lever 23. The bufiing device DI is mounted for longitudinal sliding movement adjacent a suitable guide plate 84, and is operatively connected with the hand lever 8! through the medium of a gear wheel which is secured to the hand lever and which meshes with the rack teeth 83. All parts of the apparatus shown in Fig. 5 which have not been specifically mentioned are similar in all respects to the corresponding parts of the apparatus shown in Fig. l.

The operation of the apparatus shown in Fig. 5 is substantially the same as the operation of the apparatus shown in Fig. 1. When the hand throw lever 8| occupies its normal position in which it is shown in the drawings, the device DI is moved toward the left to what I shall term its normal extreme position, but when the hand throw lever is rotated from its normal position through an angle of substantially 180 in a clockwise direction to its reverse position, the device D is then moved toward the right to what I shall term its reverse position. The parts are so proportioned that when the device D occupies its normal extreme position, it will bias the motion plate II of the mechanism B to its normal position, but that, when the device occupies its reverse extreme position, it will then bias the motion plate II to its reverse position. It follows, therefore, that the switch A will normally be moved to and locked in its normal or its reverse position according as the hand lever 8| occupies its normal or reverse position, and that the switch may be moved from its normal to its reverse position, and vice versa, by retating the hand lever 8| from its normal to its reverse position, and vice versa. The parts are further so proportioned that when the device DI occupies its normal position, the nut 25 of the operating rod 25 will engage the switch basket 21, and will thus exert a force on the movable rails of the switch through the medium of the switch basket and the tie rod 8, which force will urge the movable rails to their normal positions, and that when the device DI occupies its reverse position, the nut 25 of the operating rod 25 will then engage the switch basket 21 and will exert a force on the movable rails through the medium of the switch basket and tie rod 8, which latter force will urge the movable rails to their reverse positions; but that,

when the switch is moved from either extreme position to the other'extreme position. the nut which is out of engagement with the svritch basket at the beginning of the movement will not move into engagement with the switch basket until after the motion plate II has been moved away from its original position far enough to unlock the switch.

I will now assume that the parts are in their normal positions as shown in Fig. 5, and that a train trails the switch. Under these conditions. as the leading wheels of the train roll along the fixed rail I and movable rail 2 the movable rails become bent and move the tie rod 8 downwardly in the manner previously described in connection with the apparatus shown in Fig. 1, thus causing the piston rod 28 of the device D to move toward the right and the motion plate II of the mechanism B to simultaneously move toward its reverse position. The movement of the piston rod 28 of the device DI toward the right compresses spring 31 of this device in a manner which will be understood from the foregoing and from an inspection of the drawings, thus causing the device to exert an increased force tending to restore the rails to their normal po sitions and the motion plate to its normal position; while the movement of the motion plate I! of the mechanism B toward its reverse position unlocks the switch and causes roller I5 to move out of the straight portion at the righthand end of the cam slot I4 in the motion plate i and into the inclined central portion of the slot. As soon as the movable rails of the switch become unlocked, these rails, at the point where they are connected by the tie rod 8, are forced to substantially their full reverse positions by the wheels of the train, and this additional move ment causes further movement of piston rod 23 toward the right and motion plate II toward its reverse position. The last mentioned movement of the piston rod 28 causes additional compression of the spring 31 of the device DI, while the last mentioned movement of the motion plate causes the roller I5 of the mechanism B to move out of the inclined central portion of the cam slot I4 and into the straight portion at the left-hand end of the cam slot, thus forcing the points of the movable rails to their full reverse positions. After the points of the rails have been moved to their full reverse positions by the motion plate in the manner just described, the bufling action of the device D is effective to hold them there until the train has completely passed the switch. When this happens, the spring 31 of the device D slowly restores the piston rod 28* of the evice toward its original position, thus causing the motion plate II to move toward its normal position and the operating rod 25 to move upwardly. The force which is exerted on the operating rod be fore the motion plate has moved far enough to cause the roller I5 to move out or" the straight portion at the left-hand end of the cam slot and into the inclined central portion, causes the rails to deflect a certain amount, but as soon as the roller moves into the inclined portion of the slot, the motion of the motion plate causes the raiis to be moved to and locked in their normal positions. During a part of the movement of the rails to their normal positions by the motion plate, the nut 25 moves away from the switch basket 21, but after the movement of the rails has been completed and the roller I5 of the mechanism has entered the straight portion at the right-hand end of the cam slot M, the nut 25* again moves into engagement with the switch basket 2?, thus causing a force to be exerted on the rails at the point where they are connected by the tie rod 8 which force aids the mechanism B in holding the rails in their normal positions.

When the switch has been moved to its reverse position by means of the hand lever 8i, and a train trails the switch, the operation of the apparatus is similar to that just described except that the direction of the movement of the parts is reversed, and it is believed therefore that this latter operation will be understood from an inspection of the drawings and from the fore going description without further detailed description.

One advantage of apparatus embodying my invention over the types of apparatus heretofore employed for operating a spring. switch is that since the actual motion of the switch points is effected by a switch operating and locking device, a mechanical structure is provided which is more reliable for holding the switch points closed under normal conditions than one which depends upon a spring for holding the points closed.

Another advantage of apparatus embodying my invention over the types of apparatus heretofore employed for operating a spring switch is that by designing the motion plate properly, a high mechanical advantage at the end of the switch stroke can be obtained, and thus the points of the movable rails can be forced closed under unfavorable circumstances where, with the conventional type of spring means for closing the points sufiicient force would not'be available.

Another advantage of apparatus embodying my invention over the types of apparatus heretofore employed for operating a spring switch is that the force exerted by the points of the movable rails against the car wheels during trailing is much less than with the prior types of spring switches, and the wear on the switch points is therefore considerably reduced, thus prolonging the life of the switch and decreasing the cost of maintenance.

Still another advantage of apparatus embodying my invention over the types of apparatus heretofore employed for operating a spring switch that the movable rails of the switch are normally securely locked in both extreme positions and the switch can be trailed in either extreme position without damaging the switch.

Although I have herein shown and described only two forms of 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. In combination, a railway switch, a switch throwing and locking mechanism operatively connected with said switch, a'combined biasing and bufiing device operatively connected with said mechanism, means for moving said device in a manner to actuate said mechanism between its two extreme positions, and other means for actuating said mechanism controlled by a train approaching said switch in a trailing direction.

2. In combination, a railway switch; a switch throwing and locking mechanism movable be- 1 tween normal and reverse positions and operatively'connected with said's'witch in such manner that said switch will be moved to, and locked in, its normal or its reverse position according as said mechanism is moved to its normal or its reverse position, means including a spring for moving said mechanism between its two extreme positions, a tie rod connecting the movable rails of said switch at a point between the heel and the point of the switch, and means connected with said tie rod and responsive to the lateral bending of the rails which takes place when a train starts to trail the switch for actuating said mechanism to unlock the switch until after the train is completely past the switch.

3. In combination, a railway switch; a switch throwing and locking mechanism movable between normal and reverse positions and operatively connected with said switch in such manner that said switch will be moved to, and locked in, its normal or its reverse position according as mechanism is moved to its normal or its reverse position, means including a spring for moving said mechanism between its two extreme positions, a tie rod connecting the movable rails of said switch at a point between the heel and the point of the switch, and means connected with said tie rod and responsive to the lateral bending of the rails which takes place when a train starts to trail the switch for actuating said mechanism to reverse the switch until after the train is completely past the switch.

4. In combination, a railway switch; a switch throwing and locking mechanism movable between normal and reverse positions and opera tively connected with said switch in such manner that said switch will be moved to, and locked in, its normal or its reverse position according as said mechanism is moved to its normal or its reverse position, a device provided with a piston rod which is movable from a mid stroke position to either of two extreme positions in opposition to the bias of a spring and with means for re tarding movement of said piston rod by Said spring, manually operable means for moving said device between a normal and a reverse posit on, a bell crank lever having arm operatively connected with said mechanism, means for operatively connecting the other arm of bell crank lever with said piston rod in such man nor that said mechanism will be biased to its normal or its reverse position acccrdirs said device is moved to its normal or its reverse position, and means mechanically actuated by a train trailing said switch for actuating said mean anism to a position in which said switch is unlocked until after the train is completely past the switch.

5. In combination, a railway switch; a switch throwing and locking mechanism movable between normal and reverse positions and operatively connected with said switch in such manner that said switch will be moved to, and locked its normal or its reverse position according as said mechanism is moved to its normal or its reverse position; a device provided with a piston rod which is movable from a mid stroke position to either of two extreme positions in opposition to the bias of a spring and with means for retarding movement of said piston red by said manually operable for moving said device between a normal and a reverse position, a bell crank lever having one arm operatively connected with said mechanism, means for operatively connecting the other arm of said bell crank lever with said piston rod in such manner that said mechanism will be biased to its" noimal or its reverse position according as said device is moved to its normal or reverse position, and means mechanically actuated by a train trailing said switch for actuatin said mechanism from the extreme position it occupies at the beginning of the trailing toward its other extreme position far enough to reverse the switch until after the train has completely passed the switch.

6. In combination, a railway switch; a switch throwing and locking mechanism movable between normal and reverse positions and operatively connected with said switch in such manner that said switch will be moved to, and locked in, its normal or reverse position according as said mecli is moved to its normal or its reverse position; a device provided with a piston rod which is movable fr .n a mid stroke position to either of two extreme positions in opposition to the bias of a spring and with means for retarding movement of said piston rod by said spring, manually operable means for moving said device between a normal and a reverse position, a bell crank lover having one arm operatively connected with said mechanism, means for operatively connecting the other arm of said bell crank lever with said piston rod in such manner that said mechanism will be biased to its normal or its reverse position according as said device is moved to its normal or its reverse position, a tie rod connecting the movable rails of said switch at a point approximately midway between the heel and the point of the switch, and means for connecting said tie rod with said other arm of said bell crank lever in such manner that the movable rails of the switch at the point where they are connected with the tie rod will be biased to their normal or their reverse positions according as said device occupies its normal or its reverse position and that when a train trails the switch said mechanism will be actuated through the medium of said bell crank lever and in opposition to the bias of said device to a position in which said switch is unlocked until after the train is completely past the switch.

'1. In combination, a railway switch; a switch throwing and locking mechanism movable between normal and reverse positions and operatively connected with said switch for moving said switch to, and looking it in, its normal and reverse positions, a combined biasing and buffing device provided with a piston rod which is biased to a mid stroke position and is movable to two extreme positions and with means for retarding movement of said piston rod in response to its bias, means for moving said device bodily between a normal and a reverse position, means for operatively connecting the piston rod of said device with said switch throwing and locking mechanism in such manner that said mechanism will be biased to its normal or its reverse position according as said device is moved to its normal or its reverse position, and means mechanically actuated by a train approaching said switch in a trailing direction for operating said mechanism from the extreme position which it then occupies toward its opposite extreme position in opposition to the bias of said device far enough to unlock said switch until after the train is completely past the switch.

8. In combination, a railway switch, a member reciprocable between a normal and a reverse extreme position, means controlled by said member for moving said switch to its normal or its reverse position according as said member is moved to its normal or reverse position and for locking the switch in the extreme position to which it is moved by said member, a manually operable lever movable between two extreme positions, means including a combined biasing and buihng device for operatively connecting said lever with said ember in such manner that said member will be biased to its normal or its reverse position by said device according as said lever is moved to its normal or its reverse position and that if said member is moved away from the position corresponding to the position of lever said device will retard the return movement of said member to such corresponding position, and means actuated by a train approaching said switch in a trailing direction for actuating said member from the extreme position which it then occupies to its opposite extreme position until after the train has completely passed the switch.

9. In combination, a railway switch, a member reeiprocable between a normal and a reverse extreme position, means controlled by said member for moving said switch to its normal or its reverse position according as said member is moved to its normal or reverse position and for locking the switch in the extreme position to which it is moved by said member, a manually operable lever movable bet een two extreme positions, means including a combined biasing and builing device for operatively connecting said lever with said member in such manner that said member will. be biased to its normal or its reverse position by said device according as said lever is moved to its normal or its reverse position and that if said member is moved away from the position corresponding to the position of said lever said device will retard the return movement of said member to such corresponding position, and means actuated by a train approaching said switch in a trailing direction for actuating said member from the extreme position which it then occupies toward its opposite extreme position far enough to unlock said switch until after the train has completely trailed the switch.

10. In combination, a switch throwing and locking mechanism movable between normal and reverse positions and operatively connected with said switch in such manner that said switch will be moved to, and locked in its normal or its reverse position according as said mechanism is moved to its normal or its reverse position, a combined biasing and buffing device including a piston rod movable from a mid stroke position to either end of its stroke in opposition to the bias or" a spring and provided with means for retarding movement of the piston rod by said spring, a manually operable lever movable between a normal and a reverse position, means for connecting said manually operable lever with said device in such manner that said device will be moved to a normal or a reverse position according as said lever is moved to a normal or a reverse position, a pivoted bell crank lever, linkage connecting one arm of said bell crank lever with said mechanism and the other arm of said bell crank lever with the piston rod of said device, the arms of said bell crank lever being so proportioned that said mechanism will be biased to its normal or its reverse position by the spring of said device according as said device is moved to its normal or its reverse position, a tie rod connecting the rails at a point between the heel and the point of the switch, and an operating rod pivotally connected at one end with said other arm of said bell crank lever and operatively connected at the other end -with,sai d tie,-rodby means of a switch basket. ,and nuts on said operating rod, said nuts being I switch is moved from either extreme positionto the other the nut which is out of engagement with saidswitch basket at the beginning of the movement will not move into engagement with said switch basket until after, the switch has 'startedits movement.

' 11'. In (combination, a switch throwing and locking mechanism movable between normal and reverse positions and operatively connected with verse position according as said mechanism is moved to its normal or its reverse position, a combined biasing and bufiing device including a piston rod movable from a mid stroke position to either end of its stroke in opposition to the bias of a spring and provided with means for retarding movement of the piston rod by said spring, a manually operable lever movable between a normal and a reverse position, means for connecting said manually operable leverwith said device in such manner that said device will be moved to a normal or a reverse position according as said lever is moved to its normal or its reverse position, a pivoted bell crank lever, linkage connecting one arm of said bell crank lever with said mechanism and the other arm of said bell crank lever with the piston rod of said device, a tie rod connecting the rails at a point approximately midway between the heel and the point of the switch, and an operating rod pivotally connected at one end with said other arm of said bell crank lever and operatively connected at the other end with said tie rod by means of a switch basket and adjusting nuts on said operating rod, the parts being so proportioned that said mechanism will be moved to its normal or its reverse position according as said device is moved to its normal or its reverse position, and that when a train trails the switch the lateral bending of the rails which takes place when the train first enters the switch will act through said tie rod, said operating rod, said bell crank leverand the linkage which connects said one arm of said bell crank lever with said operating mechanism to operate said mechanism to a position in which said switch is unlocked.

12. In combination, a switch throwing and locking mechanism movable between normal and reverse positions and operatively connected with said switch in such manner that said switch will be moved to, and locked in its normal or its reverse position according as said mechanism is moved to its normal or its reverse position, a combined biasing and buffing device including a piston rod movable from a mid stroke position to either end of its stroke in opposition to the bias of a spring and provided with means for retarding movement of the piston rod by said spring, a manually operable lever movable between a normal and a reverse position, means for connecting said manually operable lever with said device in such manner that said device will be moved to a normal or a reverse position according as said lever is moved to a normal or a reverse position, a pivoted bell crank lever, linkage connecting one arm of said bell crank lever with said mechanism and the other arm of said bell crank lever with t 9 the piston rod ofsaid device, a tie rod connecting the rails at a point approximately midway between the heel and the point of the switch, and an operating rod pivotally connectedat one end with said other arm of said bell crank lever and operatively connected at the other end with said tie rod by means of a switch basket and adjusting nuts on said operating rod, the parts being so proportioned that said mechanism will be moved to its normal or its reverse position according as said device is moved to its normal or its reverse" position, and that when a train trailsthe switch the lateral bending of the rails which takes place when the train first enters the switch will act through said tie rod, said operating rod,"said-bell crank lever and the linkage which connects'said onearm of said bell crank lever with said operating mechanism to operate said mechanism to reverse said switch.

13. In combination, a switch throwing and locking mechanism movable between normal and reverse positions and operatively connected with said switch in such manner that said switch will be moved to, and locked in its normal or its reverse position according as said mechanism is moved to its normal or its reverse position, a combined biasing and buffing device including a piston rod extending through said device and movable from a mid stroke position to either end of its stroke in opposition to the bias of a spring, said device being provided with means for retarding movement of the piston rod by said spring, a manually operable lever movable between a normal and a reverse position, means for connecting said manually operable lever with said device in such manner that said device will be moved to a normal or a reverse position according as said lever is moved to its normal or its reverse position, means for connecting one end of said piston rod with said mechanism in such manner that said mechanism will be biased to its normal or its reverse position according as said device is moved to its normal or its reverse position, a pivoted bell crank lever having one arm connected with the other end of said piston rod, a tie rod connecting the rails at a point approximately midway between the heel and the point of the switch, and

the other the nut which is out of engagement with said switch basket at the beginning or" the movement will not move into engagement with said switch basket until after the switch has started its movement.

14. In combination, a switch throwing and locking mechanism movable between normal and reverse positions and operatively connected with said switch in such manner that said switch will be moved to, and locked in its normal or its reverse position according as said mechanism is moved to its normal or its reverse position, a combined biasing and bufiing device including a piston rod extending through said device and movable from a mid stroke position to either end of its stroke in opposition to the bias of a spring, said device being provided with means for retarding movement of the piston rod by said spring, a manually operable'lever movable between a normalwand a reverse position, means for connecting said manually operable lever with said device in a such manner that said device will be moved to a normal orra reverse position according as said lever is moved to its normal or its reverse position, a; pivoted bellcrank lever,.1inkage connecting one end of sai d,piston,rod with said mechanism and the otherend'offsaid, pistonrod with one arm of said bell crank lever, a tiev rod connecting, the rails at. a point approximately midway between the 'Theelandthe point ofthe switch, and an operating rod pivotally connectediat one end with said 1 dtherrarmioflsaid belltcrank lever and, operative- 11y connected attherotherend with said tie rod by means of a switch-'basketandadjustingmuts on said operatingrod, the parts beingsoproportioned that said mechanism-willbe'movedto its normal or its reverse position according astsald device is moved to its normal or its reverse position, and that when .a train trails the switch-the ilateral'ben'ding of'the rails which 'takes place when the train "first ,enters'the SWltChTWillIflCt through said tie rod, said. operating rodysaidbell crank, lever,ithe linkage which connects-said bell cranklever with said piston rod, ,said piston'rod, and the linkage which connects said .pistonirod with. said mechanism to operate. said mechanism to reverse .said switch.

THERBERTLFBONE.

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