US2585144A

US2585144A - Railway traffic controlling apparatus

Info

Publication number: US2585144A
Application number: US67393A
Authority: US
Inventors: Jr John W Logan
Original assignee: Westinghouse Air Brake Co
Current assignee: Westinghouse Air Brake Co
Priority date: 1948-12-27
Filing date: 1948-12-27
Publication date: 1952-02-12
Anticipated expiration: 1969-02-12

Description

Feb. 12, 1952 .1. w. LOGAN, JR

RAILWAY TRAFFIC CONTROLLING APPARATUS 5 Sheets-Sheet 1 Filed Dec. 27. 1948 i F-"21 l l I I l l I J JNVENTOR. fibn W Loam? J12 Fig 1.

H15 HTTOENE'Y Feb. 12, 1952 w, LOGAN, JR 2,585,144

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec. 27, 1948 5 Sheets-Sheet 2 IN V EN TOR.

fly Loaan .fv. BY 2 H15 ATTORNEY Feb. 12, 1952 Filed Dec. 27, 1948 J. W. LOGAN, JR

RAILWAY TRAFFIC CONTROLLING APPARATUS Figt 5 5 Sheets-Sheet 5 O GLWWENTOR.

John IVLoaan J1! HIS ATTORNEY Feb. 1.2, 1952 J. w. LOGAN, JR 2,535,144

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec. 27, 1948 5 Sheets-Sheet 4 Insulation Insulation 271/ Insulation my 5.

Insulaiion 24c 77 o I Q Z5 [/29 50 I f 251% I I r31 ?;b 1 51 a 54 Fig 6.

INVENTOR. Jolm W 500cm J14 HIS ATTORNEY Feb. 12, 1952 w, LOGAN, JR 2,585,144

RAILWAY TRAFFIC CONTROLLING APPARATUS Filed Dec. 27, 1948 5 Sheets-Sheet 5 sis-E INVENTOR. John W [1004112 J1? Hm ATTORNEY Patented Feb. 12, 1952 RAILWAY TRAFFIC CONTROLLING APPARATUS John W. Logan, Jr., Forest Hills, Pa., assignor to Westinghouse Air Brake Company, a corporation of Pennsylvania,

Application December 27, 1948, Serial No. 67,393

9 Claims. 1

My invention relates to railway tralfic controlling apparatus and particularly t apparatus for interlocking and coordinatin the operation of an outlying track switch with a signal controlling traffic movement over the switch.

In railway signaling and traffic controlling systems, outlying track switches, that is, switches outside of yards and interlocking plants, are

commonly protected against operation by unauthorized persons by means of padlocks which may be opened by keys carried by certain selected railway personnel. It is sometimes necessary or desirable to supplement the protection obtained from the use of a padlock by adding another switch lock which maybe controlled manually from a remote point or automatically in accordance with traffic conditions, etc. For example, when a switch is associated with a main track provided with an automatic signal system, a common expedient is to provide a time control for the switch lock. The switch lock is then provided with signal controlling contacts which are operable at any time after removal of the padlock to set the signals to stop. The timing mechanism, which may be either electric or mechanical, is started at the same time the signals are set to stop, and releases the switch lock at the expiration of a predetermined time. This period of time is chosen long enough so that any train which has passed the signal nearest the switch will have time to proceed past the switch before the lock 'is released.

The setting of the signals to stop by such a lock may be accomplished either through the use of suitable line circuits controlled by the lock or, where track circuits are employed, the lock contacts may be used to shunt the track rails. In electrified territory, the track shunting contacts must be made large enough to take care of any flow of propulsion current which might take place because of a potential difference between the rails. In such cases, the size of the contacts required is so great that they cannot be placed within the casin of the usual electric lock. The problem of properly shunting the track rails under such conditions is further aggravated by the lack of space which is typical of the congested territory where most electric railroads are located. Those congested conditions require the mounting of as much equipment as possible between the track rail, with a consequent limitation of the maximum height of the equipment.

A system of the type described, for controlling an electric lock on an outlying switch, is shown and claimed in the copending application for I 2 l, Letters Patent of the United States of Howard A. Thompson, Serial No. 749,833, filed May 22, 1947, now Patent Number 2,539,937, dated January 30, 1951, for Traffic Protection Apparatus.

An electric switch lock suitable for mounting between th rails of a railway track is described and claimed in the copending application for Letters Patent of the United States of Herbert L. Bone, George L. Temple and John W. Logan, Jr., Serial No. 721,028, filed January 9, 1947, now Patent Number 2,517,280, dated August -1, 1950, entitled Electric Locks. I 1

An object of my invention is to provide improved apparatus for interlocking a signal controlling lever with an electric lock which cooperates with a switch controlling lever, of the type described in the copending Thompson application referredto above.

Another object is to provide improved means for interlocking the manual operatinglever-of a heavy duty circuit controller with an electric lockwhich cooperates with an associated switch controlling lever. g I

Another object is to provide improved means or interlocking the hand-throw lever of a circuit controller with the foot pedal of a switch lock.

A further object is to provide an improved in terlocking structure adapted for mounting between the rails of a railway track. T

In carrying out the foregoing and other objects of my invention, I utilizean electric switch lock of the type described in the Bone, Temple and Logan application previously referred to. In the installations described herein, this lock is mounted between the rails of a crossover track so as to lock the center throw lever associated with the crossover. 7 I Y In one modification of my invention, I mount a known type of heavy duty circuit controller outside thetrack rails and, connect it through suitable linkage to a hand-throw lever mounted between the rails. I then provide an improved interlocking mechmanism connecting the handthrow lever of the circuit controller with the lever latch on the switch lock associated with the center throw lever. This interlocking mecha-. nism comprises an abutment connected tov the lever latch' of the switch look so as to move concurrently with it, and a bolt arranged to-move into and out of the path of the abutment and connected by a link to the hand-throw lever of the circuit controller. 1

In another modification of my invention, I employ a heavy duty circuit controller of the type shown in the copending application forqLetters 3 Patent of the United States of William R. Gracey, Jr., entitled Electric Circuit Controllers, Serial No. 67,264, filed December 27, 1948. This circuit controller is adapted for mounting between the track rails and is provided with a hand-throw for operating the controller contacts and another built-in hand-throw lever which is used, in the installation described herein, as the center throw lever of the crossover. A switch lock is provided to cooperate with this center throw lever, and a modified and more compact form of my improved interlocking mechanism connectsthe operating lever of the circuit controller with the lever latch of the switch look.

I shall describe two forms of railway traffic controlling apparatus embodying my invention and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view illustrating my invention as applied to a crossover track between two main line tracks, including a wiring diagram of the electric circuits and showing the principal mechanical elements diagrammatically. Fig. 2 is a track layout of the crossover shown in Fig. l, illustrating the relative locations of the various items of equipment. Fig. 3 is a plan view illustrating the electric lock for the center throw lever, the handthrow lever for the circuit controller, and the connecting interlocking mechanism, all of which are illustrated schematically in Figs. 1 and 2. Fig. 4 is an elevational view of the apparatus of Fig. 3, with certain parts shown in section and other parts broken away to permit better illustration of the essential features. Fig. 5 is a plan view of an electric circuit controller of the type shown schematically in Figs. 1 and 2 with the cover removed. Fig. 6 is a sectional view of the circuit controller of Fig. 5. Fig. '7 is a track layout similar to Fig. 2, illustrating a crossover track equipped with apparatus embodying my invention in a modified form. Fig. 8 is a plan view illustrating the center throw lever, the electric lock, the circuit controller, and the interlocking mechanism'which are shown diagrammatically in Fig. 7. Fig. 9 is an elevational view of the apparatus of Fig. 8.

In each of the several views similar reference characters refer to corresponding parts.

Figs. 1 to 4 There is shown in these figures a stretch of railway comprising insulated sections IT and 2T of two main tracks. A crossover track 3 extends from a switch I in the track section IT to a switch 2 in the track section 2T.

Each of the track sections IT and 2T is provided at its exit end with a track battery, such as I TB and at its entrance end with a track relay, such as ITR. Track relay I 'I'R controls over a front contact a signal IS governing westbound traflic. Only a portion of the energizing circuit of the signal IS is shown. The letters B and C at the opposite ends of this circuit portion represent the terminals of a local source of electrical energy such as a battery. Track relay ZTR. similarly controls a signal 28 governing eastbound traffic.

The switches I and 2 are operable by manual switch machines I W and 2W, respectively, of conventional construction. Each switch machine is provided with a hand-throw lever, such as IV and a lock bar, such as IL. The lock bars IL and 2L of both switch machines are operated from the center of the crossover track by means of a center throw lever 4, the arrangement-being generally similar to that shown in Letters Patent of the United States No. 1,654,023, issued to C. C. Thorn, on December 27, 1927, for Switch Throwing and Looking Mechanism. The center throw lever 4 is movable between the normal position shown in the drawings, in which both the switch machines IW and 2W are locked, and a reverse position in which the lock bars IL and 2L are withdrawn so that the switch machines may be operated by their respective levers IV and 2V.

An electric switch lock, generally indicated at 5, is provided for retaining the center throw lever 4 in its normal position I prefer to use an electric switch lock of the type shown in the copending Bone, Temple and Logan application previously referred to. The various elements of the lock structure shown in Fig. 1 have their functional counterparts inthe Bone et a1. lock. The structure of the elements has been modified in Fig. 1 in order to simplify the diagrammatic drawing. This lock includes a lever latch 6 which obstructs the path of movement of the center throw lever 4. away from its normal position. A pedal 1 is connected to the.lever latch 6 so that when the pedal is depressed, the lever latch is moved out of the path of the center throw lever 4. A looking member or segment 8 is connected to the pedal 1 and latch 6 for concurrent movement therewith. A locking dog 9 cooperates with the segment 8, and in the position shown in Fig. 1, the dog 9 prevents movement of segment 8. in a clockwise direction and thereby prevents release of the lever 4. by the lever latch 6.

The lock dog 9 is carried at the end of an.

armature. III, which is movable by energization of an electric lock winding I I from the locking position shown to an unlocking position in which the dog- 9 is free of the locking segment 8, so. that the segment 8 and lever latch 6 are free to move upon depression of the pedal I.

A cam 6a which move concurrently with the latch 6 operates a follower on one arm of a bell crank lever 6b. 7 The. other arm of lever 6b overlies: the locking dog 9. 'A sprin 60 biases the lever 6b in a direction to hold the follower in engagement with the cam. The cam 6a is contoured so that if the locking dog 9 sticks in its unlocked position when the latch 6 moves to its latching position, then as one arm of lever 6b follows the cam, the other arm engages the looking dog, forcing the latter to its locking position. The contour of cam 6a is so related to the structure of locking segment 8 and latch 6 that when the pedal. 1 is depressed, cam 5a can move far enough to carry lever lib away from dog 9 before the latter arrest movement of the segment 8. Thus the lever 6b does not interfere with unlocking ofdogv 9; The latch 6 is constructed so that it holds the lever 4. in the normal position shown until after thesegment 8 has passed the position where it maybe stopped by dog 9. Hence if the segment 8 is stopped by dog 9, the lever 4 remains latched.

A hollow shaft I2 (Figs. 3 and 4). is rotatably mounted at one end on the housing of the switch lock 5 and has its. other end journaled in the housing Ix3-of an interlock mechanism generally indicated at IA. The shaft I2 i provided with a torque arm I5. carrying a pin I541 extending parallel to the shaft I2. and through a suitable aperture in the pedal 1. In this manner, the shaft 12 is made to rotate concurrently with movement of the pedal I.

Inside the housing I3 of the interlock mechanism- I.4, the shaft I2 carries 'a disc. I6 provided with an eccentric aperture lBa adapted to receive a bolt II. The bolt I'I extends outwardly through and is guided by the housing I3, and is pivotally connected at its outer end to one end of a link I8. The other end of link I8 is pivotally connected to a hand-throw lever I9 mounted on a lever stand 20 and connected through suitable linkage (see Fig. 2) to a heavy duty circ'uit controller generally indicated at 2 I.

The circuit controller 2| is described in detail in connection with Figs. and 6. Referring for the moment to Fig. 1, it may be seenthat the controller 2| includes two sets of

heavy duty contacts

22 and 23 and one set of light duty contacts 24. The

heavy duty contacts

22 and 23, are made of sufficiently large capacity to shunt track circuits in electrified railways where the flow of propulsion current through such a shunt may be heavy. The contacts 22 are connected to shunt the track rails of section !T and the contacts 23 are connected to shunt the track rails of section The light duty contacts 24 are open when the parts are in the position shown in Fig. 1.. The light duty contacts 24 control circuits including a stick relay SR, and a time element relay TE, which in turn controls the energization of the electric lock winding II. The stick'relay SR is a repeater of the light duty contacts 24, and has a. pickup circuit including the contacts 24 and a back contact of the time element relay TE. The latter contact checks that the time element relay i closingits back contact whenever a timing cycle is initiated, and thereby prevents the occurrence of a shorttiming cycle due to closure of contacts 24 when the contacts of relay TS are not in their normal position. Stick relay SR also has a stick circuit including its own front contact and the contacts 24, which is independent of the back contact of time element relay TE. The energizing circuit of time element relay TE includes a front contact of'stick relay SR and the light duty contacts 24 of the circuit controller 24.

OperationFig. 1

.reverse position, the bolt I1 is moved out of the aperture I61; in the interlocking disc I6. Also, the signals IS and 28 are set to stop by the action of the

heavy duty contacts

22 and 23 in shunting the track circuits. At the same time, the contact 24 is closed, thereby energizing stick relay SR which in turn closes its front contact to energize time element relay TE. Upon energization of stick relay SR, it closes its ownstick circuit, so that relays SR and TE remain energized as long as contact 24 is closed. After the time for which the relay TE is set has expired, it closes its front contact, thereby completing an energizing circuit for electric lock winding I I. Then, as soon as pedal 1 is moved far enough to carry the end of lever 6b away from the lockjidog 9, the winding II moves lock dog 9 away from the locking segment 8 and thereby releases the pedal I, so that it may be further depressed to carry the lever latch 6 out of the path of the center throw lever 4. The center throw lever 4'may then be thrown to release the two switch machines IW and 2W. The switches I and 2 may then be reversed so that the crossover track 3 can be sed.

When it is desired to return-the parts to their normal position, the switches'l and2 must first be set normal by the use of their respective operating levers IV and 2V. The levers IV and 2V are then locked normal by returning the center throw lever 4 to its normal position. The pedal 1 may then be lifted to its normal position. After the pedal 1 is restored to its normal position, the hand-throw lever I9 of the circuit controller 2| may be restored to its normal position.

The pedal I is held down while the lever 4 is away from its normal position by means of a lever lock rod 4a (Figs. 1, 3 and 4), coacting with a lug 42) provided on the lever latch 6. During that time, the aperture I60, in disc I6 is out of registry with the bolt II, so that restoration of the hand-throw lever I9 to its normal position before the pedal I reaches its normal position is prevented.

From the foregoing, it may be seen that my improved interlocking mechanism insures the proper sequence of movement of center throw lever 4 and circuit controller lever I9. .When both levers are in their normal positions, the lever I9 must be reversed to set the signals-at stop before the lever 4 can be reversed. When both levers are in their reverse positions, lever 4 must be restored to normal before lever I9 canbe restored to normal so as to permit clearing of the signals.

Instead of providing a time control for the electromagnet II, as described, other suitable control circuits may be used. For example, the electromagnet may be controlled manuallyfrom a remote location such as a dispatchers ofiice or interlocking tower, or it may be controlled automatically in accordance with traffic conditions,

etc.

Figures 5 and 6 These figures illustrate the details of construction of the circuit controller generally indicated at 2| in Figs. 1 and 2. In Figs. 5 and 6 it may be seen that the

heavy duty contacts

22 and 23 comprise a pair of movable knife blades 22a and 23a, which cooperates with stationary spring blade contacts 22b and 23b. The knife blades 22a and 230. are pivotally mounted at one end on electrically conductive brackets 22c and 230. The free ends of the knife blades 22a and 2301. are connected by an insulating yoke 25 to one arm of a bell crank lever 26. The other arm of lever 26 is pivotally connected to a link 21, whose opposite end is pivoted on a crank arm 28 adjustably fixed on an operating shaft 29 by means of a split clamp.

The light duty contacts 24 include a pair of contact fingers 24a and 24b which are self biased to engage an insulating drum 3|] carried on the shaft 23. A conducting strip 240 is attachedto the drum 30 at a position such that the contact fingers 24a and 24b Will be electrically connected through the strip 240 when the

heavy duty contacts

22 and 23 are closed.

The brackets 22c and 230 are attached by means of bolts to suitable cables 3I which extend outwardly through insulating parts of the casing. The spring blades 23b of the heavy duty contacts are similarly connected to conductors 34 which extend outside the casing.

Figures 7 to 9 bars IL and 2L of the two switch machines IW and 2W are connected through a suitable link a'ge to acenter throw-lever-ifi' associated withta heavy: duty circuitcontroller 37, of the type. diselo'sed in the-copending applicatiomof William R. Gracey; or, previously. referred to.

The circuit controller 31 isprovided with heavy duty and light duty contacts whose func- "tionsare the :same as .for the corresponding con.- --ta'ots-in the circuit controller 2| of. Figs. 1 to .6. he'circuit controller 31..isattached to a. mounting plate 38 bolted. to. the ties of the railway track; An electric lock 39 for the center throw -lever-36= is also mountedfion the plate- 38; The electric lock 39 is-provided with. a latch which holds the lever '36 down,. and: a pedal M by means of which the latch Memay be released whenever the :electric lock 39 is. energized.

-Anyrsuitable=electric lock may be. used; but I prefer to use one of the type disclosed. in the =co'pendingsapplication for Letters Patent of the United States of. Herbert L. Bone, Serial .-No. 67,392, filed December 27, 1943, entitled .Ra-ilway l raific Controlling Apparatus.

1 -A'-18V61-10Ck-l'0d542, of conventionalrconstruction, is attached to the center throw lever 38, and cooperates with the .pedal 4| to prevent its return to its normallatching position. whenv the "hand-throw lever 36 has been moved out 'of the jawof the-latch. A. bolt-'43 isprovided, which in the position shown has one end projecting underthe pedaLAI- so asto prevent its downward movement in the latch releasing direction. This bolt 43 moves in a guideldiattached to the mounting plate-88, and its opposite end is pivo'tally-connected. to-a link 45 whose opposite end is in turn connected to an eccentric pin on the hand-throw lever '46 of the circuit controller. 31.

When the parts are in the position shown .in the drawing, audit is desired to use the crossover track, then the switchman must first operate the circuit controller by moving the handthrow lever 46from the position shown through 180 degrees to its reverse position. During. this movement, the heavy dutyv contacts of thecircuit controller shunt. the track circuit so that the signals on the main line track are set. at stop. -At the same time the end of bolt .43.moves out from under pedal 4|. Thelight duty confact. ofthe circuit controller 3! initiates the operation of a timing relay which, at the end of a predetermined period of time, energizes the electric. lock 39, so that thereafter depression of the pedal-.4l releases latch 40. and allows operation of the center throw lever 36. to release the, locks on the track switches. The switches may then be-reversedby means of their levers IV and 2V.

After the train has passed over the crossover, it maybe restored to its previous condition by throwing the two switches to their normal-positions, restoring. their. locks by returning the center throw lever 36 to its normal position, locking that lever by returning the pedal 4| to its normal position, and then operating the handthrow lever 46 of the circuit controller- 72 to its normal position.

It shouldbe noted that the pedal. 4!, when depressed, blocks the return movement of the bolt. 43 and. thereby prevents restoration of the circuit controller lever 46 to its normal position before the pedal 4! has been restored to its normal position.

A pair of brackets '41 are attached to the plate -38 so asto receive the lever 46 in its normal andreversepositions. The brackets 41. are provided; with suitable openings for the application of padlocks or other devices to prevent op- 'erationby. unauthorized persons and to hold'the lever down duringpassage of a trainover the controller.

Although I have -herein shown and described only two forms of railway trafiic controlling apparatusembodying. 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. Railway trafiic controlling apparatus, comprisinga track switch, asignal governing. traffic movements over said switch,. a lever movable between normal and reverse'pos'itions forcontrolling saidtrack switch; an electric lock for holding said lever in its normal position including a latch, a pedal for operating the latch having a normal latching position and movable therefrom to-a latch releasing position a lock dog biased to a lockin position in which it prevents operation of the pedal to release the latch, and an electromagnet for moving the lock dogfrom its locking position to a lock releasing position; an electric circuit controller having contacts for controlling said electromagnet and said signal, a hand-throw lever for said controller movable between a normal position in which the electromagnet is deenergized and the signal controlling contacts permit-clearing of the signal and a reverse position in'which the electromagnet may be energized and the signal is set to stop approaching traffic, an abutment movable concurrently with said pedal, a bolt connected to said circuit controller lever' for concurrent movement therewith, said bolt being moved between a blocking position and an unblocking position as said controller lever is moved between its normal and reverse positions, respectively, said bolt being effective in its blocking position to block the abutment and prevent movement of the pedal from its normal latching position and-in its unblocking position to permit movement of the pedal to its latch releasing position, and means operated bymovementof the switch controlling lever away from its normal position to hold the pedal in its latch releasing position, said abutment being effective when the pedal is in its latch releasing position to block a return movement of the bolt to its block position, so that the switch controlling lever must be restored to its normal position and the pedal must be restored to its latching position before the controller lever can herestored to its normal position.

2. Railway traffic controlling apparatus, comprising a track switch, a signalgoverningtrafiic movements over said switch, a lever movable between normal and reverse positions for controlling said track switch; a lock for'holding said lever in its normal position including a latch, a pedal for operating the latch having-a normal latching position and movable therefrom to a latch releasing position, a lock dog. biased to a locking position in which it preventsioperation of the pedal to release the latch, and means for moving the lock dog from its locking position to a. lock releasing. positionincl'uding time controlled. means for introducin a time. delay between initiationv of the operation thereof and the movement of the lock dog to its lock releasing position; an electric circuit controller having contacts for controllin said signal, means associated with the circuit controller for initiating the operation of said time controlled means, manual operating means for said controller movable between a normal position'in which the operation of the time controlled means is not initiated and the signal controlling contacts permit clearing of the si nal and a reverse position in which operation of the time controlled means is initiated and the signal is set to stop approaching traffic; an

abutment movable concurrently with said pedal,

and a bolt connected to said circuit controller lever for concurrent movement therewith, said bolt being moved between a blocking position and an unblocking position as said controller lever moves between its normal and reverse positions, respectively, said bolt being effective in its blocking position to block the abutment and prevent movement of the pedal from its normal latching position and in its unblocking position to permit movement of the pedal to its latch releasing position, and means operated by movement of the switch controlling lever away from its normal position to hold the pedal. in its latch releasing position, said abutment being effective when the pedal is in its latch releasing position to block a return movement of the bolt to its blocking position, so that the switch controlling lever must be restored to its normal position and the pedal must be restored to its latching position before the controller lever can be restored to its normal position.

3. Railway traiiic controlling apparatus, comprising a track switch, a signal governing traffic movements over said switch, a lever mounted between the track rails adjacent the switch and movable between normal and reverse positions for controlling the switch; an electric lock mounted between the track rails for holding said lever in its normal position including a latch, a pedal for operating the latch having a normal latching position and movable in a vertical plane to a latch releasing position, a lock do biased to a locking position in which it prevents operation of the pedal to'release the latch, and an electromagnet for moving the lock dog from its locking position to a lock releasing position; an electric circuit controller having contacts for controlling said winding and said signal, a hand-throw lever mounted between the rails and connected to said controller and movable between a normal position in which the electromagnet is deenergized and the signal controlling contacts permit clearing of the signal and a reverse position in which the electromagnet may be energized and the signal is set to stop approaching traffic, an abutment movable vertically concurrently with said pedal, and a bolt connected to said circuit controller lever for concurrent movement therewith along a horizontal path, means supporting said bolt so that it lies in the path of said abutment when the controller lever is in its normal position and prevents operation of the pedal, said bolt being moved out of the path of said abutment upon movement of the controller lever to its reverse position, said abutment being effective upon a subsequent lever releasing movement of the pedal to block a return movement of the bolt so that said pedal must be restored to its normal position before the controller lever can be restored to its normal position.

4. Apparatus for controlling the movement of trafiic over an electric railway in which the track rails are employed as conductors of propulsion current, comprising a track switch, a signal governing trafiic movements over said switch, signal control means including a track relay connected across said track rails, said-signal control means being eiiective when said track relay is deenergized by the shunting of the rails to set said signal to stop, a lever movable between normal and reverse positions for controlling said track switch; anelectric lock for holding said lever in its normal position including a latch, a pedal for operating the latch having a normal latching position and movable therefrom to a latch releasin position, a lock dog biased to a locking position in which it prevents operation of the pedal to release the latch, and an electric winding for moving the lock dog from its locking position to a lock releasing position; an electric circuit forpnergizing said winding, an electric circuit controller having light duty contacts for controlling said winding circuit and heavy duty contacts for shunting said track rails, a hand-throw lever for said controller movablebetween .a, normal position in which the winding is deenergized and the track-rails are not shunted by the heavy duty contacts and a reverse position in which the.

winding may be energized and the track rails are shunted by the heavy duty contacts, an abutment movable concurrently with said pedal, and abolt connected to said circuit controller lever for concurrent movement therewith, said bolt being moved between a blocking-position and an unblocking position as said controller lever moves between its normal and reverse polatching position in its unblocking position to,

permit movement of the pedal to its latch releasing position, said abutment being efiective when the pedal is in its latch releasing position to block a return movement of the bolt to its blocking position, so that the pedal must be restored to its normal latching position before the controller lever can be restored to itsnormal position.

5. Railway traific controlling apparatus, comprising a track switch, a signal governing traffic movements over said switch,'a lever movable between normal and reverse positions for controlling said track switch; an electric lock for holding said lever in its normal position including a latch, a pedal for operating the latch having a normal latching position and movable downwardly therefrom to a latch releasing position, a lock dog biased to a locking position in which it prevents operation of the pedal to release the latch, and an electric winding for moving the lock dog from its locking position to a lock releasing position; an electric circuit controller having contacts for controlling said winding and said signal, a hand-throw lever for said controller movable between a normal position in which the winding is deenergized and the signal controlling contacts permit clearing of the signal and a reverse position in which the winding may be energized and the signal is set to stop approaching trafiic, an abutment movable concurrently with said pedal, a bolt, a link connecting one end of said bolt to said circuit controller lever for concurrent movement therewith, and means supporting said bolt and guiding it for movement along a horizontal path, said bolt having its opposite end in the path of said abutment when the controller a lever is in its normal position to prevent a latch sitions, respectively, said bolt being eifectivein releasing operation of the pedal, said bolt being moved out of'the path of said abutment upon" movement of the controller lever to its reverse positio'm'said abutment being effective upon a subsequent leverreleasing' movement of the pedal to-block a return movement of the bolt so that said pedalmust be restored to its normal position i before the controller levercanbe restored to-its normal position.

6. Railway trafi'ic'controlling'apparatus adapt ed for mounting between"the rails of a railway track to interlock a circuit controller handthrow lever'with a switch lock pedal, comprising an abutment movable concurrently with" said pedal,-a bolt,' a lin'k connecting'one end of the bolt to thelever'for concurrent movement therewith, and means supporting said bolt andguiding it for movement along a horizontal path, said'bolt having its opposite end in the path -of said abutment when-the" lever-is in its normal quent operation of the pedal to blocks return movement of the'boltand'l'ever to their normal positions.

track, a comprising a switch-lockhaving a pedal and means supporting'the boltand guiding it for movement along a horizontal path, said bolt having itsoppositeend in the path of "said abut'-" ment'when the lever'is inits normal position to preventoperation of the pedal, said bolt being moved' out of I the path of the abutment upon movement ofthe 'lever' to its reverse position, said abutment being'effectiveupon a subsequent operation of 'the pedal to block a return move-'- ment of the bolt and levento their normal-posh tions.

8. Apparatusifor enforcing "a predetermined sequence'cf' movementbetween first and second members, each' movable between'normal "and re verse-positions; comprising a rotatable abutment position-to preventoperation ofthe pedal, said" bolt being moved out'of the" path of "the abutment: upon movement ofi the" lever to its "reverse 'posi-'" tion; said abutment'being efie'ctive' upon a subse movable concurrently with 'saidfirstmember: and having normal and reverse position :corre-' sponding to the normal and reverse positions of:

said first member, "a bolt movable concurrently with said second member along a path inter-" secting the path of'said abutment and having normal and reverse positions corresponding'td the'normal and reverse'positions of said second" member, said bolt being eife'ctive in its 'normal position to block the path of the abutmentand thereby prevent movementof thefirst'member away from its normal position, said bolt being effective when said second member is moved to its normal position to move out of the path'of the i abutment and permit movement of the first member to its reverse position, said abutment'be= ing effective when the first member is away from its normal position to block the return movement of the bolt and hence'to prevent restoration 01. the second member to its normal position.

9. Apparatus for enforcing a predetermined se quence of movement between first and: second" members, each movable between normal and re-';- verse positions, comprising an 'aperturcdrotatable disc 'connected't'o'said first member for-com current movement therewith, a longitudinally movable bolt connected to'said second member for concurrent movement therewith, said bolt be-' ing received in the" aperture in said dis'c'rwhen both members are in their normal'positions; so" that the second member'must bemoved away from its normal position before 'the'first'member can be so moved, said disc" being efiective upon movement of the" first member away from its normal position to block a restoring move ment of the bolt, so that the first/member must be returned to its normal'position'before the sec ond member can be returned'to its normal posi'- tion.

JOHN W; LOGAN; JR."

REFERENCES CITED The following references are of record in the file of this patent:

UNITEDSTATES PATENTS Number Name Date 1,639,697 Hoffman et al. Aug. 23, 1927- 2,355,989 McGowan Aug. 15, 1944-