US2361468A - Switch machine for bailway spring switches - Google Patents

Description

Get. 31, 1944. o. s. FIELD SWITCH MACHINE FOR RAILWAY SPRING SWITCHES Filed Nov. so, 1940 3 Sheets-Sheet 1 I I I II I A I III H8 m I JNVlig T ATTORNEY Oct. 31, 1944. o. s. FIELD SWITCH MACHINE FOR RAILWAY SPRING SWITCHES Filed Nov. 50, 1940 3 Sheets-Sheet 2.

INVENTOR ATTdRN EY Oct. 31, 1944., o. s. FIELD 2,361,468

SWITCH MACHINE FOR RAILWAY SPRING SWITCHES Patented Oct. 31, 1944 SWITCH MACHINE FOR RAILWAY SPRING SWITCHES Oscar S. Field, Rochester, N. Y., assignor to General Railway Signal Company, Rochester, N. Y.

Application November 30, 1940, Serial No. 368,034

8 Claims. ('Cl. 246-220) This invention relates in general to switch lock mechanisms for railway track switches, and has more particular reference to such mechanisms for switches of the lockable spring type.

The invention provides mechanism which in conjunction with a spring buffer and a usual hand operated switch stand, spring-holds the track switch in each of its two extreme positions, subject to operation by hand from either extreme position to the other, with the switch locked in the normal position, and trailable by a car from either position.

One of the objects of the invention is to provide means for unlocking the switch by a train flexing the switch rails in a lateral direction when it begins to trail the switch, and more specifically by changing the lateral flexing movement of the rail to a rotary or turning motion for transmitting such motion parallel with the track to the locking mechanism located adjacent the free ends I the unlocking of the switch to place an opposing signal at stop.

A furtherobject of the invention is to provide check means for the position of an unlocking cam on its shaft whereby to insure that either it is properly positioned or if, due to creeping of the rails, for example, it is improperly positioned, the opposing signal will nevertheless go to stop.

A further object of the invention is to provide means whereby, in the event the switch, on being trailed, does not unlock, but the lock rod breaks and the switch points move to their: other extreme position, upon the switch returning to its former position, an opposing signal cannot be.

restored to its former clear position to thus indicate that the lock mechanism is out of order.

Another object of the invention is to provide signal control means which operate differently under hand operation of the' switch, and operation of the switch when it is trailed due to the fact that when a switch is trailed it failsto reach its hand operated final position by possibly half an inch.

Further objects, purposes, and characteristicfeatures of the invention will appear as the description progresses, reference being made to the accompanying drawings showing, solely for the purpose of illustration, and in no way whatsoever in a limiting sense, one form which the invention can assume. In the drawings:

Fig. 1 is a Wholly schematic showing of a switch locking organization constituting one form of the invention.

Fig. 2 is a top plan view of a switch lock mechanism in accordance with this invention with the cover removed and parts broken away.

Fig. 3 is a section on line 33 of Fig. 2, and

- viewed in the direction of the arrows, with parts shown in elevation. v

Fig. 4 is a fragmentary view of part of the hand operating means shown positioned for use with a switch at the left hand end of a siding.

Fig. 5 is a fragmentary View of part of the hand operating means shown positioned for use with a switch at the right hand end of a siding.

Fig. 6 is a sectional view on line 6-6 of Fig. 3, and viewed in the direction of the arrows.

Fig. 7 is a sectional view of a spring buffer employed in the invention.

Fig. 8 is a sectional view on line 8--8 of Fig. 3, viewed in the direction of the arrows.

Referring now to the drawings and first to Fig. 1, there is here illustrated in a wholly schematic manner one form which this invention can assume. The various parts are positioned to facilitate explanation of the functions and operations involved, rather than with the purpose of showing the exact construction employed.

position of the track switch, by way of the switch operating mechanism. The switch locking mechanism 'prop'eris indicated as enclosed in the dashed rectangle SM.

Associated with the switch locking mechanism SM is a spring buffer SB of a construction to be described below in detail. This bufier, when the switch is operated by hand, moves as a unit but allows trailing of the switch by compression of a spring in the buffer, and after the switch,

is released, ity is returned by the spring to its former-position. Between the passing of successive car wheels, however, the switch is prevented from slapping against the wheels by means of.

Connected to the track switch is a bell crank B pivoted at l and carrying a cam including an operating portion 8 and a lost motion portion 9 which latter is concentric withpivot l. The crank is connected at one end at po'nt. ID to the track switch whereby a car passing from the siding,

onto the main track flexes the switch rails in a lateral direction and exerts a force on the crank for turning it in a clockwise direction just prior to the t'me the wheels reach the switch points.

lAn ope-rating crank pivoted at H, and biased by a spring H is in contact with the cam and turns a shaft l2 on which is adjustably fixed a switch unlocking cam-l3 having a flat idle portion l4 and an inclined raced portion: l5. The shaft l2 also carries an operating cam l6 which is adjustably fixed to the: shaft and acts upon turning of shaft l2 to open contacts I! and I8 and thereby putsignal S! to stop. Spring ll operates to normally force the point rail firmly against the stock rail, so as-to maintain adjustment.

Cam l3 operates a roller, [9 fixed to the lock bar LB so as to cam the lock bar to the left as, viewed in the drawings, against the compresson of a b asing spring 20 whereby to w thdraw the lock bolt from the lock'rod LRupon the springing of the track-rail, as described above.

In. this diagrammatic showing the lock rod is shown as two separate rods for the purpose of illustration'butin actual construction it is of course but one rod. l furthermore; the detector rod DR is shown as two separate rods-but in actual construction it is but a. single rod as will appear below.

The contacts I! and I8 for controllin si nal SI are mounted on a block 2| which is fixed in the mechanism casing. The cam I6 operates on a ro ler 22 to move a frame memberzli. which is pivoted at 24,, in a counterclockw se directon whereby to bear against an ad ustin screw 25. This sc ew is carried bya second frame member 28 which is likewise pivoted at point l whereby to move the operatirw. arm 2'1 upwardy and o en the contacts aga nst the tension of spr'ng 28.

Frame member 26 is also opera ed in a counterclockwi e direc i n u on the lock bolt being mov d to t e left bv means ofa cam face 29 opera in on a roll r M. fixed to the operat ngarm 21. The cam face 29 s c rried n a bar 3|, hearing against a portion sum the casing o the mechanism, and is conne ted tofmove w'th the lock bolt by means of rivets or the 'lkel'iZ.

This bar'3 i has a'notch 33 having an upwa dly inclined end:- 34 for a purpose to be described 1ater."-m-".- 1

As thus far d scribed. upon atra n fr aking a trail ng move the switch rails are first flexed to cam thelock bolt out of engagement with the lock rod andbymeans of cam 16 to put the si nal Si to stop before the unlock'ng of the mechanism has-been completed-and to hold itat stop after the' unlocking hasbeen. completed ,by means of thecam 29 of the upper face onthe cam bar.

Should theconnection between the track rails and the unlocking cam 'creep'or wear so as to,

produce play thereinit is possible that the unlockingv cam might get out of adjustment and fail to completely unlock the mechanism since a considerable efiort is necessary to move this unlocking cam aga'nst the efi'ort of spring 20. In case of such creeping, the cam 16 will, however, move and open the signal contacts I! and 18 to put signal SI to stop and thus safe-guard trafiic despite any lack of initial adjustment of the unlocking cam.

Upon theswitch points being moved to reverse position by a train making a trail'ng move, the detector rod DR is moved with the switch points to cause a cam notch 35 therein to move away from a roller 36 and thus force a bar 3'! to the left. This bar carries a. cam face 38 which operates, when, moved to the left, on a roller 39 to maintain the normal contacts l'll8 in an open position. The bar 37 carr'es a latch 40, pivoted at 4!, and urged in a clockwise direction by a spring 42, hearing at one end against a portion 53 of the housing. The latch has a horizontal arm G l resting on a portion of the housing whereby, unless otherwise prevented, upon. the detector rod moving with the sw'tch points to reverse position, bar 3'? is forced to the left and latch arm M drops to butt against the fixed shoulder Fit. This prevents the return of the bar under the influence of spring 42 when the detector rod has been. returned with the switch points to normal position, and thus clearing of signal Si is prevented.

In normal operation, before the detector rod has moved to'reverse position, bar (it has moved w'th the lock bolt to position its top face ll under a roller 48, carried by the latch arm 44, whereby to prevent the latch from becoming operative as to move the detector rod to reverse position.

In this case. s nce the lock bolt has not been operate'd properly the support face 47 will not be positioned to prevent latch arm 44 from becoming effective. Thus, on the switch re urning to normal position, signal Si, which should be clear under such cond'tion, will remain at stop and thus indicate that the switch lock mechanism is out of order.

When the switch is t ailed it .isnot moved to the extreme posit on that it reaches when operated by hand and fai s to reach this position by possibly half an nch Thus, on trailing, a cam notch. 49 n the detector rod fai s to move o posite a roller E'lon a spring pressed arm 5i whichonerates w en the notch is oppos t it to close contacts 52 and 53 and place the lower arm signal S2 at clear. Accordin ly a train, on leaving the siding, places the hi h signal at sto and leaves the low signal at stop when :t is making a tra ling move.

The switch can a so be operated by hand by 'means of theband operated switch stand having the operating handle 4. Assuming t at the switch isto be thrown by hand t its reverse position,

the handle 4 is moved substantially to t e left to thereby move the hand-throw rod HTR. This rod has a' pin 55. carrying a roller 55, operating a ainst a hand unlocking cam HUC, pivoted at 51, and operating an a pin and roller 58, carried. by the lock bolt LB, whereby to unlock the machine. During this unlocking movement a pin and roller 59 on the hand-throw rod moves upwardly along a vertical cam face 60 in an operating cam 0C pivoted at 6|. .Also, received in the lock bolt and the lock rod.

After the unlocking has been completed, roller 59 is beyond the vertical cam face til and enters the portion 63 of the cam opening. This permits the operating cam to swing on its pivot and move the throw rod and with it the switch points. In this operation the spring buffer SB moves as a unit, that is, as a rigid portion of the throw rod as will appear more clearly from the discussion below. I

Upon moving the switch points by the handthrow lever to reverse position, signal SI is put to stop as described above, and signal S2 is cleared as described above, since the detector rod moves far enough to cause its notch to move opposite the roller 59 and allow the contacts 52, 53 to close.

The various parts described in connection with this switch lock mechanism with reference to the diagrammatic showing of Fig. 1 are shown in a wire inlet opening 66.

The unlocking cam l3 can be seen to have an.

idle or lost motion portion 6! at each side of a socket portion 68, with cam faces 69 interconnecting these parts whereby the cam can be swung on its shaft in either direction and produce unlocking. This feature enables the use of the mechanism for either right or left hand switches. i

The hand unlocking cam HUC and the operating cam 00 are shown in Fig. 5 in the actual positions they occupied in the mechanism when the mechanism is used for a right hand switch; as shown in Fig. l.' These parts will be shifted in position as shown in Fig. .4, when the mechanism is used for a left hand switch, and the fixed pivots for these operating cams can be shifted to various receiving sockets in the mechanism casing, as shown, for example, at T0 and lll Referring now to Fig. 6, the means is here shown for connecting shaft [2 to the unlocking cam'l3. ing H; and this shaft i2 is coupled to a shaft 72 by means of a feather 13 which is pinned to the shaft 72 by a pin 'Hl (see Fig. 6). The feather T3 fits slidably in slots in the endof the hollow shaft 12 as shown in Fig. 3, to permit a limited amount of endwise movement of said shaft l2 relative to the shaft 12, while causing the shafts to turn together. This slidable universal joint connection between tubular actuating shaft 12 and the lock operating shaft "l2 allows the turning movement of the operating shaft l2, which is impartedto it by the displacement of the track rails during the trailing movement of a vehicle,

. to be communicated to the locking mechanism some distance down the track to substantially the same extent, independently of theshifting of the ties or like displacement in the relative position of the parts, thereby obviating the need for any bed plate or like means for maintaining any particular relationship between the ties supporting the lock mechanism and the actuator.

Referring now to Fig. 7, there is here shown the spring buffer SB such as shown convention- Shaft I2 is hollow and carries the housally inFig. 1, as being connected to the switch throw rod TR.

This spring buffer comprises a housing having a liquid receiving chamber 75 and a spring chamber lii'communicating therewith and normally filled with fluid, such as oil or the like. The wall 7'! of spring chamber '76 has a port 78 and 19 at each of its ends and extending inwardly of the ends only a short distance. Entering the spring chamber is a rod 80 which is connected to the throw rod, while a connection to housing 8| is connected to the track switch. Within the housing, rod I30 carries two pistons 82 and 83 which are spring pressed away from each other by a strong spring 86 and are anchored from moving further apart than is shown in the drawings by heads 85and 86 on rod to. The pistons have ports 8'! and 83 normally closed by check valves 89 and 90, having bleed ports 94 and 92 therein, and normally held in closed position by; springs 95 and 96.

As described, when the switch is operated by hand, rod Bil and the buffer casing do not move relatively to each other.

Upon the switch being trailed, however, the switch ,throw rod is held against movement by the various parts connecting it to the hand operated switch stand, whereby the spring buffer must either expand or contract, depending upon the direction of movement of the switch. In such case, the fluid in the spring chamber must pass. beyond one or the other of the pistons and can readily do so by opening the check valve at the particular end in question. As the trailing car wheels pass the switch points, and leave them, the tendency of the spring to slap the switch back under the influence of spring 84 is prevented by the check valves closing. Hence, thefluid can reenter the spring chamber only through one of the bleed ports, and thus a strong dashpot damping effect is produced.

Upon the car clearing the switch, spring 34 returns the switch to its former position. The switch first returns very slowly since the piston has moved beyond the large port 18 or H5, as the case may be. Toward the end of the return stroke of the switch, however, the piston moves opposite its large port, thereby to facilitate transfer of fluidpast the piston and the switch closes promptly and strongly with a snap.

The above rather specific description of one form of the present invention is given solely by way ofexample, and is notintended in any man ner whatsoever in a limiting sense; It is to be understood that various modifications, adaptato put the signal to stop, and check means operable by trailing movement of the switch points to hold the signal at stop if alreadyat stop, and if not at stop, to first put it to stop.

2. In track switch operating means, in combination, a track switch movable to normal and reverse position, means locking the switch in one position, means operable by a car approaching the switch in trailing direction to vunlock the switch, a signal controlling opposing 'trafllc, means operable upon unlockingthe switch to put the signal to stop, check means operable by trailing movement of the switch points to hold the signal at stop if already at stop, and if not at stop, to first put it to stop, and latch means associated with the check means and the unlocking meansand operable only if the switch was not unlocked prior to its operation, to prevent the signal from clearing upon the return of the switch to said one position.

3. In track switch operating means, in combination, a track switch movable to normal and reverse position, lock means for locking the switch in one of said positions, a wayside signal associated with the switch, control means operable by a car approaching the switch to unlock the switch and put the signal to stop, check means movable with the switch and operable to put the signal to stop if not already at stop, and to hold the signal at stop when the switch is not in said one position, and means operable to prevent clearing of the signal on return of the switch to said one position only if the signal was put to stop by said check means.

4. In track switch operating means, in combination, a track switch movable to' normal and reverse position, lock means for locking the switch in one of said positions, a wayside signal associated with the switch, control means operable by a car approaching the switch to unlock the switch and put the signal to stop, check means movable with the switch and operable to put the signal to stop if not already at stop, and to hold the signal at stop when the switch is not in said one position, means operable to prevent clearing of the signal onreturn of the switch to said one position, only if the signal was put to stop by said check means, and additional means operable to put the signal to stop on creeping of the switch rails even though the switchremains locked.

5. A locking mechanism for facing point spring switches comprising, locking means located adjacent the ends of the switch points and including a slidable locking plunger, operating means including a rotatable shaft extending along the track for moving said locking plunger a substantial distance to its unlocked position during a much smaller angular movement of said shaft, and actuator means located at some distance down the track and connected to the movable switch points at a distance from their ends for imparting such angular movement to said shaft when the switch points are flexed by a vehicle trailing them, said operating means including slidable connections permitting relative displacement of the parts lengthwise of the track by shifting of the ties or the like without interfering with the transmission of operating motion from said actuator means to said locking plunger,

6. In a locking mechanism facing point spring switches, locking means adjacent the points of the switch for locking them in their normal position, a rocking cam turnable on an axis parallel to the track and operable when turned a part of a revolution to release said locking means to permit movement of the switch points to their reverse positions, an actuator located at a distance from the ends of the switch points and responsive to the deflection of the switch rails when a train starts to trail the switch points to convert such deflection into a turning motion, and a connecting shaft extending parallel to the rails of the switch from said actuator to said rocking cam and connected thereto through a slidable connection for transmitting the turning motion of said actuator to said rocking cam for unlocking the switch independently of limited changes in the distance between said actuator and said locking means.

'7. A locking mechanism for racing point spring switches comprising, locking means adjacent the ends of the switch points and including a locking plunger movable lengthwise of the track for locked position, an operating shaft extending for a distance along the track and including a driving connection permitting relative movement of parts endwise of said shaft for actuating said cam means to unlock the switch points, and an actuator including a locking cam connected by a sliding bar to the switch points at a distance from their ends for turning said operating shaft through a small angle in response to the deflection of the switch points during the trailing movement of a vehicle, said locking cam acting to turn'said shaft to the same extent for movements of said sliding bar to a variable degree beyond a predetermined initial movement.

8. In switch control means,'a track switch, a signal, locking means for the switch points mechanically released by a car trailing the switch, circuit controlling means operable by the movement of the switch points from their locked position for putting said signal to stop, and check means rendered effective when said switch points are moved by a train from their locked position-

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