US2045695A - Control system for classification yards - Google Patents

Description

June 30, 1936. I

-' N. c, L. BROWN CONTROL SYSTEM FOR CLASSIFICATION YARDS Filed July 31, 1951 5 Sheets-Sheet 1 Fags is Mam f Jim, ATTQRN'EY June so, 1936. N. c. 1.. BROWN 5,69

I I CONTROL SYSTEM FOR CLASSIFICATION YARDS Fil ed July 31, 1951 5 Sheet sP-Sheet 2 BY M I %La/ ATTORNEY 11111630, 1936. c BROWN 2,045,695

CONTROL SYSTEM FOR CLASSIFICATION YARDS Filed July 31, 1931 5 Sheets-Sheet 3 June 1936- N. c. L. BROWN 2,045,695

CONTROL SYSTEM FOR OLASSIFIATI ON YARDS Filed July :51, 1931 5 Sheets- -She e t 4 Fle4.

/ZMM m ATroRNE'Y INVENTOR BY J June 30, 1936. N. c. 1.. BROWN 2,0 5 6 CONTROL SYSTEM FOR CLASSIFICATION YARDS Filed July 51, 1951 5 Sheets-Sheet 5 FIG. 6.

Patented June 30, 1936 Ned C. L. Brown, Scottsvllle, N. Y., alslgnor to General Railway Signal Company, Rochester,

Application July 31,1931, Serial No. 554,282 22 Claims. (01. 104-26) This invention relates to control systems for railway traflic controlling devices and more particularly to a system for centrally controlling switches and car retarders in a railway classification yard.

In railway classification yard systems, a large number of track switches are employed to properly route cars from a single in-coming track to a large number of diverging tracks classified according to their destination. Track brakes or car retarders are also employed to prevent excessive speed over such switches or undue impact when coupling with other cars in their destination track. Such track switches and car retarders are usually power operated and controlled by operators who are located in one or more centrally located towers and set up routes to properly direct each car to its classification track according to information furnished him by a previously arranged switch list. These switch lists ive the initial and number of each car in the order of arrival at the yard, their weight and the classification tracks to which they are assigned. The present type of control machines with which the operator routes these cars consists of control panels having lever operated contact means which are given numbers corresponding to the devices which they control and the operator may associate such numbers with corresponding numbers of switches or retarders designated on a miniature diagram of the classification system.

In view of the above, it is proposed to provide an improved control system in which the inconvenience and possible confusion due to the necessity of associating switch numbers with their proper control lever is avoided by providing control devices directly associated with routes over a miniature representation of the device which they govern. It is also proposed to provide indicating means in such control devices which enables the status of the traffic controlling devices to be readily apparent at all times and to provide a more convenient and eflicient means of manipulating the switch list used in such systems to thereby increase the number of trafflc controlling devices over which an operator may conveniently control traflic movements.

Other objects, purposes and characteristic fea- Fig. 1 is a diagrammatic showing of a control panel for a typical classification yard arranged according to this invention Fig. 2 is a control circuit diagram for a single car retarder and a simple track switch in accordance with this invention;

Fig. 3 is a control circuit diagram for a lap track switch also in accordance with this invention;

Fig. 4 is a sectional view of a proposed control push button to be used in the above system also included as a part of the present invention;

Fig. 5 is a side view of two push buttons of the type shown in Fig. 4 arranged to show their interlocked relation; and,

Fig. 6 is a diagrammatic showing of a proposed switch list holder and actuator also in accordance with this invention.

The control panel 1) shown in Fig. 1 may be mounted at a desk or the like and constructed of suitable fiat material of a size which enables the operator to conveniently reach all parts thereof. The panel 0 is conspicuously marked by grooves or other means to represent the layout of the actual track, and in this disclosure a typical system is assumed such as shown in Fig. 1. In this system shown, various classification tracks numbered consecutively from 1 to 36 may be alined, by a series of switches, with a single in-coming track I.

The point at which each of the representations of track in Fig. 1 diverges, represents a switch in the actual track layout, and each route over such switch is represented by a push button Pi etc. which is so located as to make its associated route readily apparent. Each car retarder unit is also represented in a corresponding position on the panel 0 by five transversely spaced push buttons, each of which is arranged to effect different degrees of retardation.

It is now obvious that, with a system of push buttons thus arranged, a distinctive condition may be quickly set up which will represent the alining of a route to any one of the 36 tracks shown. It may be found expedient for the operator to start at the particular destination on the control panel and depress all switch control push buttons which are included in a route from there to the in-coming track, as for example, if it is desired vto route a car to track 3|, push buttons Pl, P2, P3 and P4 are depressed. The proper retarder push button to be depressed in the various units included in such routes may be judged by the operator from the weight of the car given on his switch list or by observing the actual speed at which the car is moving.

The manner in which these push buttons function to control the tramc controlling devices is diagrammatically shown in Figs. 2 and 3, which show the push buttons in a very diagrammatic manner, as a manually operable button M arranged, when depressed, to operate contact means and having an indicating lamp L included therein which is visible through a lens or glass S in the top of the button M. These push buttons are biased to an upper position and are interlocked by suitable means which is clearly shown in Figs. 4 and 5 and which will be fully described hereinafter.

Referring now to Fig. 2,a section of the operators control panel 0 which includes the controls for a simple switch and a car retarder is shown with a diagrammatic illustration of each push button associated with its position thereon by dotted lines. A simple track switch TSI is shown as operated by a switch machine SMI which is controlled by push buttons P5 and P6 and a car retarder R. is illustrated as operated by a retarder mechanism RM (shown as a dotted rectangle) which is controlled by the push buttons P1, P8, P9, Pill and PI l.

A short track circuit Tl including the switch TSI is energized by a source of energy TBI and two relays TRI and TR2 are connected so as to be selectively energized from this track circuit according to the positions of the push buttons P5 and P6. These relays TR! and TR2 each have compound windings with one winding of each, Wi and W2, adapted to pick up its armature when energized from the track section '1 and a second winding of each, HI- and H2, arranged in series with the switch machine operating circuit, is adapted to hold the armature up after having been previously picked up by the first winding.

The push button P5 representing the normal route over the track switch TSI is shown depressed in Fig.2and the track switchTSl is shown as operated to its normal position in accordance therewith. The indicating lamp L5 in the push button P5 is thus energized over the following circuit:beginning at one terminal B of a source of energy, wires 31 and 38, contacts 39 of the switch machine SMI bridged by a shunting block 40 in its normal position as shown, wire 4|, lamp L5, wires 42 and 43, front point 44 and contact 45 of relay TRI, wires 45 and 41 to the other terminal of the source of energy. The indicating lamp L5, being energized, then indicates directly on the operators control panel 0 that a normal route is alined over the track switch TSI and that the track section Ti is unoccupied.

If it is now desired to aline a reverse route over the track switch TSI, the push button P8 is depressed which sticks down and releases the push button P5 which then returns to its upper position as will be described hereinafter. Relay TRI, having been energized from the track section Tl over wire 48, contacts 49 and 50, wire 5|, winding WI and wires 52 and 53, is now deenergized and relay TRZ is energized over the track circuit Tl over 'ferring to the drawings.

13, contacts 14 and I5 bridged by a shunting block 15 in its normal position, wire 11, motor field Fl wire ll winding C0 of the brake BR. to the opposite terminal C of the source of energy. This causes the switch machine SMI to operate the 5 track switch TSI to its reverse position and shift the contact shunting blocks 40, I0 and 18 to their reverse position in preparation for the return operation of the switch machine.

The shifting of the contact shunting block 40 10 deenergizes the indicating lamp L5 and energizes the lamp LG from the terminal B of the aforesaid source of energy, wires 31 and 19, contacts bridged by block 40 in the reverse position, wire 8i, lamp L6, wires 82, 43 and 83, front point 15 84 and contact 85 of relay TR! and wires 86 and 41 to the opposite terminal C of the source of energy. The energizing of the indicating lamp L8 now indicates to the operator that a reverse route is alined over the switch TSI and that the 20 track section TI is not occupied. It is obvious that when the section TI is occupied both relay TRI and relay 'I'RZ will be deenergized and thereby extinguish both indicating lamps by interrupting their common circuit at the parallel contacts 45 and 85.

The operation of the switch TSI back to its normal position may of course be accomplished by pressing push button P5 which in a similar way releases P6 and is effective to aline a normal 3n route in a manner which is now obvious by re- It will also be noticed that if both push buttons P5 and P6 are pressed at the same time, P5 only will be effective as the circuit ordinarily completed by P6 includes a con- 3:,

tact made only with P5 in an upper position.

To obviate the possibility of any operation oi the switch machine SMI when the track section TI is occupied, as by a short, or cross the following shunt circuit on the switch machine 40 motor is established by both relays TRI and TR2 deenergizedz-beginning at the terminal 0 of the operating energy, contact 64 of relay TRZ deenergized, wire 65, contact 66 and back point 61 of relay TRI deenergized, wire 68, contacts 45 89 shunted by block 10, wires H and 12, armature Al, wire I3, contacts 14 and 75 shunted by block 16, wire 11, field winding Fl, wire 18, wind ing C0 of the brake BR to the same terminal C of the operating energy. It is obvious that 50 with the switch machine SMI in its reverse position, a similar shunt circuit is also established over the reverse control circuit whenever the track section TI is occupied.

Push buttons P'l, Pl, P9, PIU and Pi I are posi- 55 tioned on the section of the control panel 0 to represent the location of the retarder R and may be arranged from the operators left to right to represent various successive degrees of retardation as shown in Fig. 2. These retarder push 60 buttons may be of the same type and interlocked in the same manner as those'used in the switch control previously described and are effective to selectively energize any one of five circuits leading to the retarder mechanism RM. It will be 65 noticed also that the circuit which each push button is arranged to complete includes series contacts on each button of lesser degree which contacts are made only with the buttons in the upper position. Thus, in the. event that more 7 than one push button is depressed at the same time, only the lesser degree button will be effective.

The. retarder mechanism represented by the dotted rectangleRM ma'y include an arrange- 7 ment such as shown in the patent to W. K. Howe No. 1,757,428 dated May 6, 1930 in which the five push buttons of this case are replaced by the manual control lever and'can be used in combination with relays, and-contactors shown In this patent to cause the retarder R to assume any one of five positions in accordance with whichever push button is depressed.

An indicating lamp in each push button is energized by a contact closed when the button is depressed and a relay SR is connected in series with the common energy circuit to these push buttons which relay is. arranged to extinguish all the retarder indicating lamps when energized by the retarder control current, or in other words, when a selected push button is depressed, the operating energy for the retarder mechanism RM flows in series with the winding of the relay SR thus depriving all the indicating lamps of energy until this operating circuit is broken by contacts in the retarder mechanism BM in a manner disclosed in the above mentioned patent. These indicating lamps then indicate directly on the control panel the status of this retarder only when the retarder mechanism has operated into correspondence with the selected position.

The control circuit shown in Fig; 3 uses apparatus which is similar to that used in the simple switch layout in Fig. 2, but is arranged to select any one of three routes by pressing push buttons associated therewith. In this arrangement, two overlapping track switches T82 and TS3 are respectively operated by switch machines SM2 and SM3 and their control is effected by four relays TR3, TR4, TR5 and TR6 which are selectively energized from track circuit energy by push button PI2, PI3 and PI4. Three track sections T2, T3 and T4 may be employed and respectively energized by three sources of energy TB2, TB3 and T34, as shown. The central one of these sections T3 may control a relay CTR which is arranged to deenergize the relays TR3, TR4, TR5 and TR6 when this central section is occupied and it is obvious that the first section T2 controls relays TR3 and TR4 and likewise the last section T4 controls relays TR5 and TR6.

The push button PI2 in the section of the control panel 0 is shown depressed and a left diverging route in accordance therewith is alined by the switch TS2 in its reverse position. An indicating lamp LI2 in the push button PI2 is accordingly energized over the following circuit:-beginning at a terminal B of a source of energy, wires 81 and 88, contacts 89 of switch machine SM2 shunted by block 90, wire 9|, lamp LI2, wire 92, front point 93 and contact 94 of relay CTR, wire 95, front point 96 and contact 91 of relay TR3, and wires 98', 99, and I00 to the opposite terminal C of the source of energy.

The circuit which was effective to energize relay TR3 upon pushing the button PI2 is as followsz-beginning at a rail of the track section T2, wires I02, I03 and I04, push button contacts I05 and I06 closed, wire I01, winding W3 of relay TR3, wires I08 and I09, contact H0 and front point III of relay CTR,-wire H2 to the opposite rail of the track section T2.

The relay TR3 being energized closes the following operating circuit for the switch machine SM2z-beginning at the terminal B of a source of energy, wires H3 and H4, winding H3 of relay TR3, wire H5, front point H6 and contact H1 of relay TR3, wire H8, contact H9 and back point I20 of relay TR4, wire I2I, switch machine contacts I22 then shunted by block I23 in its normal operated position, wires I24 and I25, switch machine motor armature A2, wire I26, contacts I21 and I28 shunted by block I29 in its normal operated position, wire I30, switch machine motor field F2, wire I3I, winding C0 of the brake BR to the opposite terminal C of the source of energy. This circuit being completed was efiective to aline a left diverging route by operating the switch machine SM2 to a reverse position thereby shifting its contact blocks 90, I23, and I29 to the position now shown and complete the indicating circuit previously described.

Considering that it is next desired to aline a straight through route in the layout of Fig. 3, the push button Pl3'on the operators panel 0 is depressed which releases the push button PI2 and energizes the relays TR4 and TR5. The

energizing circuit for relay TR4 may be traced 20 as follows:beginning at a rail of the track section T2, wires I02, I03 and I04, contacts I 05 and I32 of push button PI2 in its upper position, wire I33, contacts I34 and I35 of push button PI3 depressed, wires I36 and I31, winding W4 of relay 25 rail of the track section T4, 35

The return of push button PI2 to its upper position deenergizes relay TR3 by interrupting its circuit at contacts I05 and I06 and consequently when the relay TR4 is energized the following normal operating circuit for switch machine SMZ is completed:beginning at a terminal B of a source of energy, wires I I3 and I48, winding H4 of relay TR4, wire I49, front point I50 and contact I5I of relay TR4, wire I52, contact I53 and back point I54 of relay TR3, wire I55, contacts I56 of switch machine SM2 shunted by block I23, wires I51 and I26, motor armature A2, wire I25, contacts I58 and I28 shunted by block I29, wire I30, motor field F2, wire I3I, winding C0 of the brake BR to the opposite terminal C of the source of energy. The completion of this circuit results in theoperation of the switch machine SM2 to its normal position which accordingly shifts the shunting blocks 90, I23, and I29 to their normal operation position which is opposite to that shown.

It will also be noted that the energizing of relay TR5 sets up a similar normal operating circuit for the switch machine SM3 but as this switch machine is already in such a position, no operation thereof takes place. The straight through route is thus alined with both switch machines SMZ and SM3 in their normal position and the indicating lamp LI3 in the push button PI3 is energized over the following circuit:beginning at a terminal B of a source of energy, wires 61 and I59, contacts I60 of switch machine SM2 shunted by block 90 in its normal operated position, wires I6I and I62, contacts I63 of switch machine SM3 shunted by block 201 in its normal operated position, wire I64, indicating lamp LI3, wires I65, I66, and I61, front point I68 and contact I69 of relay TR5 energized, and wires I10 and I00 to theopposite terminal C of the source of energy.

It is now obvious that a right div ging route may similarly be alined by pressing push button PI4 which is effective to energize relays T84 and TRO thereby establishing a normal operating circuit for switch machine 8M2 and a reverse operating circuit for switch machine 8M0. Inasmuch as these circuits-are similar to the ones dust traccd, it is not considered necessary to trace them in detail.

When these switch machines 8M2 andBMl have assumed a position alining the aforesaid route, an indicating circuit is completed to the indicating lamp LI4 which includes contacts of switch machine 8M2 made in its normal operated position which contacts are in series with contacts on switch machine 8M0 made in its reverse'operated position. It will be noted that when the track sections T2. T0 and T4 are occupied, a shunt is established on the operating motors of these switch machines SM2 and 8M0 in the same general manner as in the simple switch arrangement previously described.

The arrangement illustrated in Fig. 3 shows a layout for routing cars in any one of three tracks by employing what is generally termed a lap switch layout, but it is desired to be understood that this circuit arrangement may equally well be applied to the conventional three-throw or slip switch layout which is interchangeable with the overlap arrangement shown. In either of such layouts, i. e. the present lap switch, and the alternative slip switch, a single track section to replace sections T2, T3 and T4 may be employed to control a single track relay which in turn may deenergize the four relays TR3, TR4, PR5 and TRt when this track section is occupied, by means of this single relay supplying energy through its front point to wires I00 and I42 in multiple. It is obvious that such an arrangement although more economical would not have the operating flexibility possessed by the three track sections.

A proposed construction of a push buttdn P which may be employed in the previously described circuits is shown in the sectional view in Fig. 4 and this single type of push button may be mounted on the operator's panel in interlocked groups of two or more as illustrated in Fig. 5. This push button consists of a cylindrical button M having a cover glass S secured in its top by a threaded ring 202, and an insulating ring 203 threaded and adapted to screw on to the lower end of the button M when assembled. A frame member 204, havinga top cylindrical guide arranged to receive the button M, has two downwardly extending sides which holdwan insulating socket member 205 by through bolts 206. The button M may be inserted in the cylindrical guide in the frame member 204 and screwed into the insulating ring 203 which then stops the downward motion of the button M by engaging an annular shoulder on the socket member 205 as well as limiting its upward motion by engaging the lower end of the aforesaid frame guide. A compression spring 201 resting on the top of the socket member 205 engages the ring 200 thereby biasing the button M upwardly.

The socket member 205 has a downwardly extending stem portion by which it is held to the frame 204, and may also serve to hold resiliently movable contacts 208 each side thereof which are biased to normally engage resilient contacts 209 and are operable to engage similar contacts 2I0. Two insulated resilient terminal strips 2 extend through the base of the socket 200 and sulating ring 200 forces the movable contacts 200 ..insuiated body bushings (not shown).

movable contacts 200 extend into the path m the button M so that when depressed, the ininto engagement with the fixed contacts 2" and out of engagement with the contacts 200. A shaft 2 is rotatably held in the frame member 204 and is sufficiently long to include each push button in the interlocked group. A locking dog D is secured to the shaft 2 at each push button by a pin HI and is biased inwardly by a spring I12. This dog D is so positioned that when the button M is depressed, the dog is forced outwardly by the insulating ring 200 thus rotating 2 the shaft 2 and causing a corresponding motion of the other dogs attached thereto. When the button M has reached its extreme lower position, the lower end of the dog D clears the insulating ring 200 and is forced inwardly by the 25 spring I12 to retain the button M in its lower position when the pressure thereon is removed.

Referring now to Fig. 5 which shows the right hand push button retained in 'a depressed position as described above, it is obvious that when 30 the left hand push button is depressed the looking dog thereon is forced outwardly which rotates the locking dog on the right hand push button correspondingly through the shaft 2 thereby releasing the right-hand button and retaining the left-hand button depressed. It is seen that any number of push t ns may be interlocked in like manner so that when one is depressed, any others which are then retained depressed will be released, thus making effective only the last selected push button in the group.

The apparatus shown in Fig. 6 shows diagrammatically a proposed means for manipulating the switch list by which the operator is guided in routing the cars over the system. This list should be mounted in a convenient location preferably at a point above the control panel where it may be conveniently read by the operator. A side view of such a switch sheet is shown as X in Fig. 6 which may be of any convenient size and should include the necessary information concerning each car to be classified in spaced horizontal lines thereon.

It is proposed to actuate this list X between a large roller I13 and a small roller I14 each time a car is disposed of by being released over its route. The small roller I14 is rotatably sup ported at the ends of arms I10 which are biased by' a spring I10 to hold the list X against the large roller I13. The large roller I10 is mounted on a shaft I11 by which it is rotatablyheld in bearings (not shown) and the ends of this shaft I11 may have knobs I10 secured thereto by pins I19 whereby it can be manually turned.

A ratcheting arm I00 is rotatably held on the shaft I11 and carries a double pawl IOI which is engageable with teeth on a ratcheting wheel I02 secured against rotating motion to the shaft I11. This double pawl IOI is biased by an over center buckling spring I03 to engage either the lower end or the upper end thereof with the teeth of the wheel I02 according to which side of center the spring I00 is manually buckled. This spring I00is arranged to absorb the ratcheting motion of the pawl III in either of the above mentioned positions without being bent to a beyond-center position, which thereby provides a resilient biasing means for the pawl I8] as well as a means for manually shifting the direction of ratcheted motion of the roller I13.

A pedal means for actuating the ratcheting arm I80 is provided by a pivoted pedal I84 which operates to force the arm I80 upward through a connecting rod I85, and a spring I88 is included to return the arm I80 to a lower'position. An electro-magnetic means for lifting the arm I80 is also provided by an electro-magnet I81 operating an armature I88 connected to the arm I80 by a link I88. This electro-magnetic means may be controlled manually by a push button I80 arranged to energize the electrmmagnet I81, as shown, and this push button may be conveniently located on or near the operator's control panel.

It is also proposed to provide an automatic means for actuating the ratcheting arm I80 by a track treadle I9I which is operated by each wheel of a car passing thereover. This treadle I9I may be located at the in-coming track, such as I in Fig. l, and is employed to close an electrical circuit to an electro-magnet I92 which operates a ratchet wheel I83 by an armature I94 biased by a spring I85 and having a pawl arrangement I96 attached thereto. The ratcheting wheel I93 has a dog I91 operating to permit'only uni-directional rotation thereof and has a cam wheel [98 attached thereto which is arranged to lift the ratcheting arm I80 through an extension I80 thereon once for every four operations of the electro-magnet I92 thereby ratcheting the roller I13 one space for every car, i. e. every four wheels, passing over the track treadle I9I.

A manual cut-out switch I99 which opens the circuit controlled by the track treadle I8I is provided to disconnect the automatic means just described when it is desired to operate the ratchet by either the manual or the pedal means. It is obvious that either the automatic, the manual or the pedal means can operate the ratchet arm I80 which in turn can notch the roller I13 one space in either direction through the pawl II, which direction is effected by the selected position of the spring I83. To retain such forward ratcheted motion of the roller I13, a resilient detent 200 is provided which exerts a retaining force on the roller I13 when resting between the teeth thereon, as shown.

A classification yard control system has thus been disclosed which is extremely simple in its operation, which provides readily apparent means for indicating the status of each controlled device thereof, which has a control panel with so compact control apparatus thereon that a complete system may be conveniently controlled by a single operator, and to avoid confusion of the operator, such control apparatus is so located on a miniature representation of the actual track layout that their function is readily associated therewith and to further increase the efliciency of the system an accurate and time saving means for manipulating the operator's switching sheet is also provided. And the present invention has further disclosed as an economic feature, a unit push button which may be assembled in the required groups to thereby increase the flexibility of the system.

In describing the present invention, attention has been directed to one specific embodiment thereof, without attempting to point out the various alternate or optional features of construction, or the diflerent organizations or combinations that may be employed. For example, the Q current supplied to the track sections in Fig. 2 and Fig. 3 is shown as a battery but an altemating source of current may as well be used by employing the conventional transformer and rectifler arrangement, and indication selectors such as conventionally used in interlocking with suitable windings thereon may be substituted for the relays TRI, TR2, etc. The specific construction of the push button shown is also merely suggested as one way in which a device may be made which will function as required in the system disclosed herein. Other types of switch machines may also be employed in this system, such as the well known type which does not include the magnetic brake as shown herein, but relies upon dynamic snubbing which may be obtained by making slight changes in the control circuits all of which is well known in the art.

In other words, the particular embodiment of the present invention has been selected to facilitate in the disclosure thereof rather than to limit the number of forms which it may assume, and it is desired to be understood that various modifications, adaptations and alterations may be applied to the specific form shown to meet the requirements of practice, without in any manner departing from the spirit or scope of the present invention except as limited by the appended claims.

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

1. In a control system for classification yards, in combination, a classification yard, a control panel marked to simulate the layout of said classification yard, switch control push buttons arranged to represent routes over switches on said control panel, car retarder control push buttons arranged on said control panel inprogressiveorder of retardation at a location thereon to simulate the location of the associated car retarder, individual contacts operated by said push buttons to selectively energize circuits which are effective to distinctively operate associated traflic controlling devices, means in each push button arranged -to indicate when the condition of the associated trafflc controlling device corresponds thereto, and means interlocking the push buttons associated with each traflic controlling device whereby any one of such interlocked push buttons is retained depressed and is released by a subsequent depression of another push button interlocked therewith.

2. In a control system, a miniature track diagram, push buttons on said track diagram arranged to represent various conditions of traific controlling devices in said system, means interlocking the push buttons which are associated with each trafiic controlling device whereby a depressed push button is retained in such a position until released by the depression of another push button interlocked therewith, contacts operated by the depression of said push buttons,

mal route over each track s ,vitch thereon, a push button arranged to represent a reverse route over each track switch thereon, a switch machine operably connected to each of said track switches, a normal and a reverse control relay associated with each of said switch machines, said control relays having an operating winding and a holding winding thereon, track circuits extending through each track switch in said system, said track circuits including contacts operated by an associated normal control push button and contacts operated by an associated reverse control push button whereby either an associated normal control relay or an associated reverse control relay may be selectively energized, a normal and a reverse operating circuit for each of said switch machines each of which operating circuits includes a series holding winding and anenergized contact of the associated control relay and a deenergized contact of the other control relay and shunting circuits for the operating motor of said switch machines effective when both the associated normal and reverse control relays are deenergized.

4. In a control system, a track switch power operated by a switch machine, a miniature representation of said track switch, a push button on said miniature representation arranged to simulate a normal route over said track switch, a push button on said miniature representation arranged to simulate a reverse route over said track switch, a track section including said track switch, a track circuit completed-by said normal push button in a depressedposition including the rails of said track section, contacts of said normal push button and windings of a normal control relay for said switch machine, and a track circuit completed by said normal push button in an upper position and said reverse push button in a depressed position including the rails of said track section, contacts of said normal push button, contacts of said reverse push button and windings of a reverse control relay for said switch machine.

5. In a control system for classification yards, a car retarder, a control panel having a group ofpush buttons located with respect to a miniature track diagram thereon to simulate the location of said car retarder, individual contacts operated by said push buttons, a source 01' energy, control,circuits for said car retarder associated with each of said push buttons and are ranged to be selectively connected with said source of energy by the depression of said associated push button, said push buttons being arranged to represent various progressive degrees of retardation of said car retarder, said control circuits including series contacts of each push button representing lesser degrees of retardation and said series contacts being made with said lesser degree push buttons in an upper position.

6. In a control system for classification yards, a car retarder, a control panel having a group of push buttons representing various degrees of retardation of said car retarder, a source of energy, control circuits for said car retarder selectively connected to said source of energy by the depression of the associated push button, a relay connected in series with said source of energy and said control circuits, indicating means associated with each of said push buttons and having individual energizing circuits including contacts on its associated push button closed during depression thereof and each of said indicating circuits being-interrupted by contact means on said series relay when energized.

'7. In a control system for railroad yards, a track switch power operated by a switch machine. a control panel, a normal control push 5 button on said control panel arranged to effect the normal control of said switch machine, a reverse control push button on said control panel arranged to effect the reverse control of said switch machine, individual indicating means in 10 said normal control push button and in said re-, verse control push button, circuit means energizing said normal indicating means when said switch machine is in its normal operated position, circuit means energizing said reverse indiis eating means when said switch machine is in said reverse operated position, and a track circuit arranged to control both said normal indicating circuit means and said reverse indicating circuit means.

8. In a control system for railroad yards, a section of railroad track constituting a straight through route and having a power operated track switch therein controlling a right hand diverging route therefrom and a power operated track 25 switch-therein controlling a left hand diverging route therefrom, a miniature representation of said section of railroad track, individual push buttons on said miniature representation arranged to' simulate said right hand diverging route, said left hand diverging route and said straight through route over said section of track, insulated track sections individually including said track switches, a source of energy at one end of each section, a normal control relay and a reverse control relay associated with each of said power operated switches, control circuit means whereby said relays may be distinctively energized from said associated track sections in accordance with a depressed push button, operating circuits for the switch machines, means arranged to distinctly operate said switch machines in accordance with the energization of said associated control relays and a shunt for each operating circuit effective when both of the associated control relays are deenergized.

9. In a railway control system, a three-way track switch arrangement power operated by switch machines, individual push buttons corresponding to the three routes over said switch arrangement, track circuits including said switch arrangement, a normal and a reverse control relay for each of said switch machines, energizing circuits for said control relays including said track circuits whereby said control relays may be selectively energized by depression of said push buttons, indicating means in each of said push buttons, individual energizing circuits for said indicating means including contacts on said switch machines made when the condition of said 60 switch machine is in accordance with the route represented by the push button and contact means interrupting said indicating circuits when ticular trafllc controlling device being interlocked whereby the operation of one contact means releases other contact means interlocked therewith and retains said operated contact means. 7 5

11. In a control system for railway yards, a miniature diagram of a yard having manually operable contact means each so locatedon said diagram as to simulate a condition of a trafllc controlling device associated therewith, said contact means being interlocked with other contact means associated with the same trafllc controlling device and having individual indicating lights therein visible on said miniature diagram.

12. In control systems for railway yards, in combination, a miniature diagram of an actual yard having a trafllc controlling device, a plurality of control means on the diagram for governing the said device, the control means being so located on the diagram as to simulate a condition oi. said device, each control means being movable to operated position against biasing means, and interlocking means for the plurality of control means whereby operation of one control means releases all the others and retains the operated one in operated position. i

13. In control systems for railway yards, in combination, a miniature diagram of an actual yard having a traiilc controlling device, a plurality 01' control means on the diagram for governing the said device, the control means being so located on the diagram as to simulate a condition of said device, each control means being movable to operated position against biasing means, and interlocking means for the plurality of control means whereby operation of one control means releases all the others and retains the operated one in operated position, a circuit controlled by each control means and arranged so that but one circuit can be effective at any one time to affect the traflic controlling device.

14. In a control system for railway systems, in combination, an insulated track section, a device associated with the section, ope'rating means for the device, control circuits for the operating means, a track circuit including the track section and a plurality of track relays, a corresponding plurality of manually operable control members, the control circuits being controlledby the track relays, and the track relays being controlled by the control members.

15. In a control system for railway systems, in combination, an insulated track section, a device associated with the section, operating means for the device, control circuits for the operating means, a track circuit including the track section and a plurality of track relays, a corresponding plurality of manually operable control members, the control circuits .being controlled by the track relays, the track relays being controlled by the control members, a holding winding on each relay, each control circuit including a back point or a track relay and a holding winding of a different track relay.

16. In a control system for railway systems, in combination, an insulated track section, a device associated with the section, operating means for the device, control circuits for the operating means, a track circuit including the track section and a plurality of track relays, a corresponding plurality of manually operable control members, the control circuits being controlled by the track relays, the track relays being controlled by the control members, an operating winding on each track relay, an energizing circuit for the operating winding of one relay including only a contact controlled by one of the control members, and an energizing circuit for the operatingwinding of another relay including, in series, contacts controlled by a plurality of the control members.

17. In a control system for railway systems, in

combination, an insulated track section, a deof a track relay and a holding winding of a difterent track relay, an operating winding on each track relay, an energizing circuit for the operating winding of one relay including only a contact controlled by one of the control members, and an energizing circuit for the operating winding of another relay including, in series, contacts controlled by a plurality of the control members.

18. In a railway track switch layout, two overlapping track switches, a power operated means for operating each switch respectively, a first pair of translating devices for controlling one of the means, a second pair of translating devices for controlling the other means, a push button arranged to jointly control one device of each pair of devices, a push button arranged to control the other device of one pair, and a push button arranged to control the other device of the other pair.

19. In a railway track switch layout, two overlapping track switches, a power operated means for operating each switch respectively, a first pair of translating devices for controlling one of the means, a second pair of translating devices for controlling the other means, a push button arranged to jointly control one device ofeach pair of devices, a push button arranged to control the other device of one pair, a push button arranged to control the other device of the other pair, and indicating means in each button to indicate the response of a power operated means to its button.

20. In a railway track switch layout, two overlapping track switches, a power operated means for operating each switch respectively, a first pair of translating devices for controlling one of the means, a second pair of translating devices for controlling the other means, a push button arranged to jointly control one device of each pair of devices, a push button arranged to control the other device of one pair, a push button arranged to control the other device of the other pair, means retaining each button in depressed position upon being depressed, andmeans releasing the retaining means of any depressed button, upon depressing another button.

21. In a railway track switch layout, two overlapping track switches, a power operated means for operating each switch respectively, a first pair of translating devices for controlling one of the means, a second pair of translating devices for controlling the other means, a push button arranged to jointly control one device of each pair of devices, a push button arranged to control the other device of one pair, and a push button arranged to control the other device of the other pair, a normal and a reverse operating circuit for each power operated means, the normal operating circuits for both power operated means being completed by the depressing of the button which controls two of the translating devices.

22. In a railway track switch layout, two overlapping track switches, a power operated means for operating each switch respectively, a first pair of translating devices for controlling one of the means, a second pair of translating devices for controlling the other means, a push button ar ranged to jointly control one device of each pair of devices, a push button arranged to control the other device of one pair, a push button arranged to control the other device of the other pair,

and indicating means in each button to indicate the response 0! a power operated means to its button, a normal and a reverse operating circuit for each power operated means, the normal operating circuits for both power operated means being completed by the depressing of the button which controls two of the translating devices.

NED C. L. BROWN.

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