US1706851A - Hump-yard interlocking - Google Patents

Description

March 1939- w. K. HOWE I 1,706,351

HUMP YARD INTERLOCKING Filed July 23, 1923 2 sheets sheet l Flcaji. I

TB O O w/zw A TORNEY March 26, 1929. w, ow 1,706,851

HUMP YARD INTERLOCKING Filed July 23, 1.923 2 Sheets-Sheet 2- Patented Mar. 26, 1929.

UNITED STATES P T OF WINT HROP K. HOWE, OF ROCHESTER, NEW. YORK, ASSIGNORJTO GENERAL SIGNAL COMPANY, OF ROCHESTER, NEW YORK.

RAILWAY HUMP-YARD m'rannocxme'.

Application filed m 23, 1923. Serial No. 653,220.

This invention relates to a system for operatingby power the switches of classification or hump yards of railroads.

In sorting cars, making up. trains, and

handling freight cars in general, it is common practice to employ a special arrangement of tracks and switches, usually on a' grade, which iswell known in the art and commonly known as a hump, gravity or classification yard. Ordinarily, the switches of such a classification yard are thrown by hand by the switch men; but, for various well known reasons, it is desirable to be able to operate all or the more important switches of a classification yard from a central point by power under the control of one operator.

On account of the slow speeds and active supervision, such a system oi-power operation of switches does not need necessarily all of the safeguards and refinements required in a power interlocking system for terminals,

crossings, and the like; and on account of the size of these yards and the .number of switches involved, it is desirable to make the system of power operation as cheap and simple as the practical requirements and working conditions permit.

Generally speaking, the primary object of this invention is to provide a simple andefficient scheme for the power operation of a large number of switches from a central control point, with such indications and safeguards as are considered to be necessary for practical use. More specifically, this invention contemplates the provision of a cheap I and eflicient quick acting machine for throwmg a switch by electric power from a central supply under the control of an 0 erator; a-

' simple arrangement for cutting- 0 supply of power to a switch machine and preventing its operation while a detector track circuit adjacent thereto is occupied, so that the switch can not be thrownunder a car, this protective arrangement at the same time permitting the switch machine to complete the stroke of the switch if once started prior to the occupancy of the detector track circuit; the rovision of a switch machine which permits t e switch points to be trailed and which keeps switch so points in their shifted position until them].- or train has passed, whereupon the st. itch is automatically returned to its former position in correspondence with the position of its controlling lever; provision of'facilities for operating any switch by hand whenever rehereinafter as thedescription pro quired and with safety; the provision of suitable indications at the switch and at the central control point or tower corresponding to theexisting position of the switch points; the incorporation of a dynamic braking or snubbing arrangement for the motor operating the switch machine so that, in spite of its quick operation, the parts of the mechanism are not injured b shock or jar at the end of each stroke; an the arrangementof the control devices or levers in the tower in such a fashion that they are readily accessible to one operator, can be easily and quickly mlani ulated, and can not be accidently disace P Various other characteristic features and specific objects of the invention will appear ses.

In the accompanying drawings, igure 1 shows diagrammatically and in accordance with established conventions a simple typical single switch layout, together with the devices at the switch and the control tower constituting the system of this invention, and including the various control circuits of this system;

Fig. 2'is a plan view of the switch machine diagrammatically illustrated in Fig. 1. having its cover partly broken away;

Fig. 3 is a detail section taken on the line 3-3, Fig. 2, and shows means for lifting a contact finger from a movable contact block for cutting energy off of the switch machine;

Fig. 4 is a detail section taken on the line 4-4. Fig. 2;

Fig. 5 is a side elevation of a lever andits casing for controlling the switch machine shown in Fig. 2;

Fig. 6 is a front elevation of the lever shown in Fig. 5;

Fig. 7 is a plan view of two of the switch levers shown in Fig. 5, illustrating how they may be assembled to form an arc of a circle;

Fig. 8 is a sectional view taken on the line 8-8, Fig. 5, as viewed in the direction of the 100 arrows;

Fig. 9 shows a portion of the switch lever illustrated in Fig. 5, with the leverin an intermediate position, and with the snap switch arm just on a point of throwing over to the reverse position; and

Fig. 10 is a view similar to that of Fig. 9 with both the lever and the switch arm in the reverse'position.

Generally stated, the system of this invention consists of a number of control devices, conveniently termed levers, arranged together in a convenient manner in a machine located in a tower or other desired point of central control. Difl'ering from ordinary interlocking practice, there is no mechanical interlocking between the several levers. In addition to the levers, and their associated circuit controllers, there are indicators for each lever, a safety or control relay, and perhaps a track relay or repeater, these various parts being preferably assembly in unit form in separate casings and connected together in the arc of a circle with such radius that all of the levers may be easily reached by the operator at the center. In the tower, or adjacent thereto, is preferably located the source of operating current assumed in this instance to be a storage battery of, say, 110 volts, with the necessary recharging equipment, control panel, and the like. In addition to this operating source, there is preferably used in this invention a source of alternating current which is distributed throughout the yard by suitable power lines.

At each switch is a detector track circuit and track relay, the small pot light signal, and a switch machine for operating the switch points, the casing of this switch machine also housing a transformer for the pot signal and the track transformer. The switch machine comprises, in addition to an automatically operated circuit controller for controlling its own operating motor, a circuit controller shifted tocorrespond with the position ofthe switch points for controlling the indication of the pot signal and the indicators of the corresponding lever in the tower.

Switch machine-The specific construction of mechanism embodying this invention for shifting switch points and performing the other desired functions maytake various forms, and the specific design illustrated in Fig. 2 is intended to be merely typical. Referring to Fig. 2, a switch machine and associated parts are supported .and housed in a box-like casing 1 having the usual tightly fitting and detachable cover 2, said casing having two pairs of projecting feet 3 extending from opposite sides thereof and facilitating the attachment of the switch machine casing to a pair of ties with the usual spacing. The switch points are shifted and held in their extreme positions by a single throw-- bar TB, which extends transversely of the casing and is guided by recesses inthe side Walls thereof, detachable cover plates 4 facilitating the removal of this throw-bar. The end'of this throw-bar isconnected by a throwrod and adjustable switch connection to the switch points in the usual way, as indicated diagrammatically in Fig. 1. This construction, being well known, needs no particular illustration or description.

As clearly shown in Fig. 2, the throw-bar TB is formed with a laterally opening U-shape jaw 5 between its ends, the sides of this jaw forming shoulders 6 which engage sides of the casing and accurately determine the extreme position of said throw-bar, it being understood in this connection that variation in the throw of, the switch points is taken care of by the adjustable connection between the throw-bar and said points. The throw-bar TB is reciprocated by a lever or gear sector GS, which is pivotally supported upon a pin 7 securely fixed in the base of the casing 1, said sector GS being held in place by the usual washer and cotter pin. Fixed in the end of the sector GS is a pin 8 carrying a revolvable roller 9 adapted to cooperate With the jaw 5 of the throw-bar TB and cause reciprocation thereof when said sector is rocked back and forth. On the same pin 8 is journaled the end of a thrustsrod 10, the other end of which slides in a block 11 swiveled on a pin 12 fixed in the base of the casing 1 (see Fig. 4). Between the block 11 and a collar 13 fixed to the rod 10 is a strong compression coil spring 14.

The sector or lever GS is rocked or oscillated by the rotation of'a pinion 15 meshing with the teeth on said sector GS. This pinion 15 is driven from a bevel gear 16 through a friction slip clutch of suitable construction, such as disclosed, for example, in my prior application Ser. No. 304,816, filed June 17, 1919, this clutch being indicated b dottedlines17. Thebevelgear16mesheswitfi a bevel pinion 18 pinned to the armature shaft of the operating motor M. This motor M is of the series direct current type, with the usual field and armature; and is preferably wholly enclosed, as shown, and bolted directly to the end of the casing 1.

In connection with the operation of the switch machine SM, it is necessary to provide circuit controlling contacts automatically opened and closed during the cycle of openat-ion of the machine. Also, it is desirable to provide a circuit controller which is actuated in correspondence with the position of the switch points and may be used to control the signal at the switch and the indicators in the tower. These two circuit-controllers are both operated by the movement of the gear sector GS. The circuit controller governing the operation of the switch machine, conveniently termed pole changer P, consists of two parallel blocks 20 of insulating material fastened to brackets 21 integral with one wall of the casing 1. F astened to these insulating blocks 20 are spring contact fingers, as 22, specific designation of these fingers and their inter-connection into the operating circuits being taken up hereinafter in the description of the operation. An angle or bell crank lever 24 is pivotall supported on a pin 23 in a plate 25 fixed to a side wall of the casing 1. The longer end of this angle lever 24 has fixed thereto a block 26'of insulating material, in which are embedded or secured short contact pieces or strips 27 adapted to bridge pairs of the contact fingers 22. Also connected to this longer end of the lever 24 is an over-center throwing spring device, which comprises a plunger '28 pivotally secured to said lever and guided in a swiveled block 29, similar in construction to the block 11 hereinbefore described, and a spring 30' shelves or brackets 34, similar to the pole changer P. An angle lever ispivotally supported on a stationary pin 36 and carries at its free end insulated contact pieces co-- 0 eratingwith the contact springs, in much t e same way asalready described in connection with the pole changer P. The outer end of this angle lever 35 is guided by a pin 37 traveling in a slot formed in a bracket 38, integral with the casing 1. The shorter end of the angle lever 35 is provided with a roller 39. engaging in a cam slot in the gear sector GS.

To facilitate manual operation of the switch machine, the hub of the pinion 15 is formed with'a square socket to receive a crank or similar tool, by means of which said pinion may be turned by hand. Such manual operation of the switch machine is necessary in case the mechanism is for some reason out of order, the, circuits broken, or the power supply cut 011'; and while under such conditions 1t is ordinaril not possible for the machine to be operated by power, it is considered expedient to assure that all power shall be cut off and disconnected from the switch machine before it can be moved by hand. Otherwise, on account of the automatic restoring features of this type of machine, as hereinafter more fully explained, the switch man might be seriously injured in attempting to operate by hand a switch which had not had its power cut ofi. For

. this purpose, amovable guard for the crank socket in the pinion 15 is used in such a way that, before the crankcan be inserted, this guard must be moved and in' so doing the switch man cuts oif the power of the switch machine.

In the particular arrangement shown, a

a swinging lever 41 'is pivotally supported'on apin 42, and one end of this lever has a hole through which the crank must pass in order to enter the socket in the pinion 15.. The

other end of thelever 41 is connected by a link 43 to a crank 44 (see Fig. 3), the shorter end of said crank 44 carrying a striking piece 45 of insulating material adapted to on age an extension on a lon contact finger o a pole changer P and ralse that finger out of engagement with a contact piece on the lever 24, thereby cutting off the supply of current to the motor M. The parts are so propor-' tioned that the lever 41 partly covers the crank socket for the pinion l5, and when displaced to permit. the insertion of a crank, raises the long/contact finger and cuts ofl' the supply of power.

- Lever um't.As already explained, the socalled levers for controlling the switch machines of the several switches are made u in units of like construction and are assem led together, preferably in a curved tier. The description of one of these lever units will sufiice for all;

Every lever unit Kcomprises a casing of cast iron or sheet metal, which is wider at one end than at the other (see Fig. 7) and is securedto inner and outer curved an le bars 50 and 51 of the main framework for the machine. Each of these casings is made up of one side wall 52, a front wall 53, and back and bottom walls, one side of the casing being open. When these casings of the lever units K are secured to the angle bars 50 and 51 side by side, as shown in Fig. 7 the side wall 52 of one casing serves to close the open side of the adjacent casing. Any one of these lever units ma be separately removed; and it is evident t at when taken out, all parts of the unit are accessible to inspection and repair through the open side. The connecting wires of the lever units are taken up through a hole 54 in the bottom of the casing The lever itself is a slidable bar 55, which projects at one end through the front'wall 53 of the casing, this projecting end being formed with a handle to facilitate the reciprocation of this bar or lever. In the lower edge of the lever 55 are two notches 56 which engage the front wall 53 when the lever is in its extreme position and drops down by its own weight. In this simple Way, the lever 55 is held against accidental movement either in or out from its extreme positions, so that there is no chance of its accidental displacement by one leaning against it or by' one tion of thecorresponding switch machine by 0 ening and closing certain circuits. 1 According to this invention, the circuit controller operated by the lever 55 is of the quick acting or snap type and is always closed in oneektreme position or the other. This circuit-controller comprises, generally speaking, two rows or tiers of contact fingers arranged in pairs and a swinging contact arm which carries insulated contact rings bridging said pairs of fingers. More specifically, referring to Figs. 5 and 7, two contact carrying blocks 57 of suitable insulating material are secured to the back wall 52 of the casing; and to these insulating blocks are fastoned contact fingers, as 58, arranged, as best shown in Fig. 7, in pairs. The contact arm 59 is preferably constructed, for the purposes of clearance, in an inverted U-shape form or bifurcated; and this arm is pivotally supported at its lower end on a fixed stud 60, being held in place by the usual Washer and cotter pin.

To this contact arm 59 is attached a threaded member 61 on which are secured a number of insulated contact rings 62 adapted to engage and bridge pairs of contact fingers 58 as said arm is swung from one extreme positionto the other. Pivotally supported upon the same fixed stud 60 is a lever 53 of peculiar angle shape, as shown in Fig. 5. The shorter and downwardly projecting end of this lever 63 is pivotally connected by a pin 64 to the lever 55, so that the lever 64: is rocked from one extreme position shown in Fig. 5 to the other extreme position shown in Fig. 10 as the lever is reciprocated. lhe other and upwardly projecting end of the lever 53 is pivotally connected to a plunger 65'which slides through the transverse hole in a pin 66 secured between the two bifurcations of the contact arm 59. On this plunger 65, between the head thereof and the pin 56, is a compression coil spring 67. A Ushaped member, conveniently called the hammer or striker 68, is rigidly fastened to the lever 55; and fixed in one of the bifurcations of the contact arm 59 is a pin 89 positioned so as to be engaged by the striker 68.

The operation of this snap or quick acting circuit controller is best understood from consideration of Figs. 5, 9 and 10. Fig. 5 shows the parts in one extreme position, the lever 55 being pushed all the way in, and the contact arm 59 being in the leithand position. As the lever 55 is pulled outward, the lever 53 is rocked about the pin 60, and the I upper end of this lever is carried up and to the left with respect to the pin 65 of the'contact arm 59. After a certain distance of movement of the lever 55, the parts assume the position as shown in Fig. 9, in which the spring 67 has been compressed and is acting substantially on a line with the pivotal axis of the contact arm 59.

Upon movement of the lever beyond the position just discussed, the lever 63 is moved still further to a point where the spring 5? acts on the opposite side of the pivotal axis of the contact arm 59 and tends to throw said contact arm from the lefthand position toward the right. Ordinarily, onaccount of the friction of the engagcment'of the contact rings 62 with the contact fingers 58, the spring 67 may not be strong enough to move the contact arm 59; but y referring to Fig. 9, it can be seen that after the lever 55 has been moved part way the lelthand side of the striker 58 isbrought in position "to engage the pin 69 on the contact arm 59, thereby positively connecting the lever with said contact arm and pulling it free irrespective of the frictional engagement of its contacts. As soon as the contact arm 59 is free to be moved by the spring 67, it is thrown over quickly with a snap action to the other righthand position shown in Fig. 10.

It will be observed that the circuit controller of the lever, according to this invention, must always be closed in one position or the other. Aside from producing quick break and make of circuits'and avoiding injury to the contacts due to arcing, this snap circuit controller has another important feature in connection with the use of detector track circuits controlling the supply of electric current to the switch machine, this advantageous feature being more conveniently discussed hereinafter.

In connection with the'salety provisions for preventing operation of a switch under a car, there is employed in this invention a safety or control relay for each switch and lever unit, this relay being preferably located at the tower and in the casing of the lever unit. Referring to Fig. 5, this safety relay as shown, is i of the iron-clad type with a high resistance coil 70 and a low resistance coil 71, both surrounding a vertical movable core 72. The core 72 is connected by insulated blocks to a contact linger 7 3, which is hin ed at one end to an insulated binding post la, and which carries a contact (preferably oi carbon) at the other end movable into engagement with a cooperating carbon contact carried by an insulating binding post 7 5. Contact linger 73 is biased to the open position by its weight and the weight of the core72. When the coils 70 or 71 are effectively energized in the manner hereinafter explained, core 72 is raised, closing the circuit controlled by this contact finger.

man or operator the position oi the several switches under his control, small indicator lamps o and 1- are provided for each lever unit one for each position of the switch. These indicators may have distinctive color, letter or sign significance. As illustrated each or these indicator lights or signals comprises a cylindrical casin 77 having a threaded hole in the bottom which is fastened to the front wall 53 of the lever unit casing by a flanged sleeve 78. A small lens or bulls eye 79 is suitably secured in the outer end of the sleeve Z8. struction and containing a lamp 81, is fastened 1 For the purpose out indicating to the tower A lamp socket 80 of suitable conto the other end of the casin 77, preferably by a spring flange frictional y engaging the outer end of said casing. Each of the levers is preferably identified in the usual way by a number plate 82.

Organization of the system.-In Figure 1 is shown in a simplified and diagrammatic manner a track layout and control circuits for a single switch SW. In this particular layout, the track rails of the main track or superior route are desi ated 83,.and the track rails of the siding, ranch track, or turnout are designated 84. These track rails 83 and 84, fora portion of their length at least near the switc SW, are bonded in the usual way and rovided with insulated joints 85 and cross onds 86 to give the usual detector track circuit and fouling point protection.

In the particular embodiment of the invention illustrated, this detector track circuit is energized with alternating current derived from the secondary of a track transformer TT, the usual current limiting impedance or resistance 87 being interposed in the connections soas to avoid excessive current flow when the train is standing on the track section. The circuits by which current is supplied to the primary of this track transformer TfT are more conveniently considered hereina ter.

The track relay T for the detector track circuit since the use of alternating current is assumed, is of the well known two-element alternating current type havin a local phase field winding-88 and a track phase field winding 89. As well known by those skilled in the art of railway signaling, such a two element A. C. relay is responsive to both the existence and phase relation of the currents in its field windings, this relay being in effect a three-position device. The contact fingers and cooperating stationary contacts of this relay are shown in accordance/with established convention as single switch arms and. arrows. This track relay (part shown in dash rectangle) may be located near the switch and the circuit controlled thereby taken to the tower, or at the tower and the connections to its track phase winding carried out to the switch, as may be most convenient or suitable.

For the information of the switch men and train crews, there is preferably employed a small pot color light signal at the switch g ving the usual color indications corresponding to the positions of the switch points, such as green and red. The specific construction of this signal S, which may be of any one of the well known types modified in proportions for the purpose, has not been shown,

utin the wiring diagram of Fig. 1 there are indicated two lamps G and R of this signal. As shown, the lamps of the signal S are supplied, with alternating current from the small transformer LT. Running throughout the yard is a pair of alternating current b! Wires or mains 90 and'91, supplied from a suitable source, shown as a step-down transformer 92 lighting transformer LT has its primary connected by wires 93 and 94 to one of these supply mains 90 and by wires 95 and 96 to a dimming switch 97 said switch 97 being shiftable from the position shown in connection with the other energy main 91 by wire 98 to the other position where connection is made by a wire 99 to a lower voltage tap on the secondary of the main suppl transformer 92. The dimming switch 97, w 'ich is prefera ly located in the tower or at some other central control point and which referably controls the light transformers L for all switches or for large groups thereof, is employed in pracconnected to a high voltage supply. The

tice to change the voltage supplied to the lamp signals S to give a strong indication for day time and a weaker in ication for night time.

The pole changer circuit controller P and the indication circuit controller IS of the switch machine have been shown convention-- ally and diagrammatically; and similarly the snap circuit controller of the lever has been shown in a simplified and diagrammatic manner.

Operation-The operation of the complete system may be readily comprehended by consideration of the operation of a single unit in minal of the li hting transformer LT, wire 100, contact SPllIlgS 101 and cooperating contact pieceof the indication circuit controller IS, wire 102, lamp G, wire 103 back to the other terminal of said secondary.

The primary of the track transformer TT is supplied with current by a circuit con-' trolled by the contacts of the indication circuit controller IS, this circuit being traced as follows :Commencing at the energy main 90, wires 93, .104 and 105, contact s rings 106 of the circuit controller IS, wire 10 primary of transformer TT, wire 1.08, contact fingers 109 and wires 110 and 111 to the other energy main 91. With the primaryv of the track transformer TT energized by this circuit just traced, the phase relation or instantaneous polarity of the currents flowing in the track phase field 89 and the line phase field 88 of the track relay .T are such. as to cause the contact fingers of said relay to assume the righthand extreme position. indicated, this With .the contact fingers of the track relay T in the normal position, and with the 0011 tact arm '59 of the lever in the normal position shown, the indicator n is lighted by a circuit which may be traced as follows z-Commenc ing at the energy main 90, wires 112 and 113, indicator a, wire 114-, contacts 115 of the lever, wire 116, contact finger 117 of the relay T normal, and wire 118 to the other energy main 91. P

The pot signal S serves to inform train men near the switch that this switch is in the normal position. The indicator n in the tower serves to inform the operator or lever man that the particular switch corresponding thereto is in the normal position, and further that the detector track circuit associated with that switch is not occupied.

Assume now that the lever man desires to reverse the switch SW and put-it in the reverse position to divert a car' or number of cars on to the siding or turnout. Observing that the indicator n is lighted, the lever man knows that the detector track circuit of the switch SW is clear and that the switch may be properly thrown. To throw theswitch, the lever man pulls out the bar or lever 55, first raising its outer end to free the notch 56. The contact arm 59 is thrown from the lefthand or normal position shown to the righthand'or reverse position with a snap action in the manner previously explained. Referring to Fig. 1, and imagining the contact arm 59 to be in the reverse position opposite to that shown, there is established a circuit for energizing the safety or control relay CR, provided the indicator track circuit is not occupied, which is the condition assumed to exist, this circuit being traced on the drawings as follows :Commencing at the battery B, wires 120 and 121, high resistance winding of the relay OR, wire 122, contact finger 123 of the track relay T normal, wires 124:, 125 and 126, low resistance winding 71 of the relay QR, wire 127, contact spring 128 of the lever, contact arm 59 being now reversed, wires 129 and 130, contact springs 131 of the pole changer P, wire 132, armature A of the switch machine motor, wire 133, contact spring 13 1 and its cooperating contact piece, long contact spring 135 (assumed to be closed because no crank is in place in the switch machine), wire 136, field F of the motor and wires 137 and 138 back to the=battery B.

It will be noted that this circuit includes the high resistance winding 70 and the low resistance winding 71 of the relay GR in series; and the resistances of these windings are so proportioned, with due regard to the voltage of the battery B, and resistance of the 'niotor, such that there will not be sufft cient;, current-fiowing in this circuit to start the motor but enou h current to raise the core 72 (Fi 5) and lift contact finger 73 of the 'relay R into engagement with its cooperating front contact. When the front contact of the relay OR is closed, currentfrom the battery B may then fiowdirectly through wire 140, said front contact 7 3, wires 141 and 126, through the low resistance winding 71 of the relay CR direct to the motor M of the switch machine. In other words, closing of the front contact of the relay CR shunts out its high resistance winding and also the track relay contacts. By excluding the high resistance winding 70 of the relay CR from the motor circuit, the resistance is reduced so that sufficient current for operating the motor M is supplied. The motor M now rotates the pinion 15 through the friction clutch 17 in a direction to rockthe gear sector GS counter-clockwise; and this movement of the gear sector GS causes reciprocation of the throwbar TB in an obvious manner. Upon the first movement of the gear sector GS, and preferably as quick as mechanical clearances will permit, the lever 35 of the indication circuit controller is shifted to its intermediate or middle position, in which all contact springs of said circuit controller are disconnected or unbridged.

Referring now to Fig. 1 and assuming the movable contact carrier of the indication circuit controller IS to be in the middle or intermediate position, it will be noted that both of the lamps of the pot signal S are extinguished, thereby signifying that the switch is operating or in mid-stroke. Also, the supply of current to the track transformer TT is cut off by the opening of contact springs 106 and 109, whereupon contact fingers 117 and 123 of the track relay T assume the neutral or middle position due to the biasing force common in relays of this character. The

dropping of the track relay T at this time breaks the circuit for the indicators n and r extinguishing both indicators and signifying to the operator in the tower that the switch is operating or is in mid-stroke.- When the contact finger 123 assumes its neutral position, under the conditions considered, no effect is produced upon the operation of the switch machine, since the front contact 73 of the control relay GR is closed and current may be supplied to the motor ofthe switch machine independently of the dropping of the track relay, it being understood that the front contact 73 of the control relay is retained in its upper or closed position due to the flow of operating current for the motor through the low resistance winding 71.

Thus, as soon as the switch machine starts its operation, the indications of the pot signal S and the lever indicators n and r are extinguished, but the supply of current to the operating' m9tor of the 'switchgmac' hine is maintained by, the 'action -gof theCOIltifOl {relay CR,1irrespct1ve of the dropping of the track relay T.

-As the switch machine continues its operation, the spring 14 is compressed and after the gearsector has moved beyond its middle position, this spring tends to expand and force the throw-bar TB to the other extreme position. At the appropriate int in the movement of the gear sector G say about threefourths of its stroke, the lever 24 of the pole changer P is shifted to the other extreme position by the action of the cam slot 32, said lever 24 having been held in its normal extreme position shown in Fig. 2, independently of the cam slot, by the action of the spring 30. i

When the contact carrier of the pole changer P is shifted to the opposite extreme position, the supply of current to the operating motor is interrupted at the contact springs 131 and 134-135. Current now ceases to flow through the low resistance winding 71 of the relay CR and the contact finger 73 drops by gravity to the lower open position. Al-

though the operatin current of the motor is cut off, the stroke 0 the switch is completed by the spring 14, so that eventually the contact carrier of the indication circuit controller is shifted from its middle position to the opposite extreme position. This results in closing energizin circuit for the red lamp Rof the pot signal 5 ing at the secondary of the transformer LT, wires 1 00 and 150, contact spring 152, wire 153, lamp R, and wire 103 back to said secondary.

Also the primary of the track transformer TT is agaln connected across the energy mains 90-91, but with its polarity reverse This new or reverse energizing circuit of the primary of the track transformer TT may be traced as follows :-'Commencing energy main 90, wires 93, 104 a d 154, contact springs 155, wires 156 and 1 8,. primary of transformer TT, wires '10? and 157, contact springs 158, and wires 159 and 111 back to the other energy main 91.

By comparing the circuit just traced with the circuit previously described for energizing track transformer TT under the normal conditions, it will be noted that the terminals of the primary of this transformer have been oppositely connected to the energy mains. For example, the energy main 90 is connected to the lefthand terminal of the primary of the transformer TT with the switch normal and to the righthand terminal with over a circuit'that ma lever is now in the reverse position, results in the energization of the reverse indicator 7' be traced as follows :Starting with t e energy main 90,

wires 112 and 160, indicator 1', wire'161, contact-springs 162, wire 163, contact finger 117 of the track relay T reversed, and wire 118 as follows :Commenc-- at the back to the other energy main 91. The lighting of the indicator 1' signifies that the switch has properly completed its operation in the reverse position and that the track circuit is not occupied. When the car or train for which the switch has been reversed enters thedetector track circuit, the indicator lamp 1' then goes out, since the track relay'T is deenergized; and in this way the lever man is advised that thecar or train is taking the switch. When acar or cars have passed beyond the fouling point, track relay T is again energized and the indicator 1" lighted, whereupon the lever man knows that he may return the switch back to the normal position if he so desires.

In order to handle the cars expeditiously- .which serves to slow down the movement of the parts of the switch machine at the end of the stroke and cause them to come to rest without objectionable shock and ar.

As previously explained, the operating current of the motor is out off at some intermediate point before the throw-bar has reached its extreme osition, the final-movement of said throw Bar and the completion of the stroke of the switch points, being 3000111- plished by the action of the spring 14. When the pole changer P is shifted to cut off operating current to the motor M, it is thrown from 'one extreme position to-the other; and when in the other-extreme position, the armature and field of the motor, with their connections reversed, are connected in a closed circuit of low resistance. on account of the reversal of the armature and field connections, the residual magnetism in the field and armature cores acts with the armature rotating, to generate dynamically a current in this closed circuit; but since the generation of this current requires power, it is obvious that the rotation of the armature is retarded or braked, this action being similar to that occurring in various systems of dynamic braking. v

Assuming that the switch has just been thrown to the reverse position, as previously explained, with the lever-in the reverse position and the contactsof the pole changer P shifted to the reverse position, opposite to that shown in Fig. 1, the dynamic or snubbing circuit may be readily traced as follows Commencing at, say, lefthand brush of the armature A, wires 133 and 142, contact springs 143, wires 144 and 145, contact springs 146 of the lever, now in the reverse position, wires 147 and 137, field F of the motor, wire 136, long contact spring 135 and contact spring-148, wires 149 and 132 back to the other brush of the armature.

By comparison of the circuit just traced with the circuit over which current for operating switch machines flows, it will be observed that the connections between the arm ature A and the field F have been reversed. Explaining more in detail, with the contacts of the pole changer P in the normal position shown in Fig. 1, it will be noted that the lefthand brush of the armature A is connected to the lei'thand terminal of the field F; whereas with the contacts of the pole changer P reversed, the righthand brush of the armature A is now the one connected to the lefthand terminal of the field F.

This dynamic braking-not only serves to absorb the momentum of the rotating armature of the motor, and the gearing operated thereby, but also cushions the action of the spring 14, so that the throw-bar TB is brought to rest in its extreme posi.- 'tions without a severe shock. On account of the use of the spring 14 for completing the stroke of the switch points, it is possible to cut 011' the current of the motor M and begin dynamic braking some time before the throw-bar reaches its extreme position, and makes it possible to utilize to any desired extent the snubbing action of the motor to cushion the movement of the parts at the extreme positions.

As already stated, it is not possible to operate the switch while its detector track circuit is occupied, because under these conditions the track relay T is deenergized and cuts off the supply of current to the switch machine irrespective of the position of the lever. Although the switch machine is preferably made quick in its operation, taking perhaps a second and a half, it may happen, particularly in a busy yard, that after the operation of the switch machine has been initiated but before it has completed its stroke, a car may enter the detector track circuit and deenergize the track relay. Under these conditions, it these were no provisionother than the track relay for the control of the supply of current to the switch machine, current would be instantly cut off and the switch might stop in an intermediate position. On account of the spring 14, however, it is very unlikely that the switch points will stop in a middle position, said spring acting to throw them one way or another, unless the throw--bar should happen to stop with the spring 14 acting on a line with the pin 8 and the pivotal axis of the sector GS. All possibility of stopping the switch points in mid-stroke is avoided, however, by the provision of the safety or'control relay UR. r

As previouslv explained, before the motor can start, the front contact of the relay CR must close and when this has happened, operating current is maintained on' the motor wholly irrespective of the operation of the track relay, and this current is maintained until the switch machine has completed its cycle of operation and the operating current is broken at the switch machine itself, whereupon the contact finger 73 of the relay CR drops. In short, by the incorporation of the safety relay OR in the system, it is assured that a cycle of operation of the switch machine, once started, will be completed in spite of the entrance of a car in the detector track circuit.

Another important feature of this invention relates to the provision made to permit switches to be trailed through, that is, run through by a car although not set in the proper position. For example, referring to Fig. 1, the switch S may be set in the normal position shown and acarmove from the siding or turnout track on to the main track, it be ing evident that in so doing thecar must force the switch points over. Referring to Fig. 2, it can be seen that the switch machine is so constructed that the switch may be trailed and the points forced over without injury to the mechanism. The throw-bar is not positively locked, as in some switch machines, but is merely held in its existing extreme position by the spring 14. Accordingly, when the switch is trailed, the throw-bar may be forced to the other extreme position by merely compressing the spring 14. Such movement of the throw-bar is, of course, accompanied by the forced movement of the gear sector, pinion 15, and armature of the motor; but if this movement is too abrupt for the armature of the motor to follow, injury tov the parts is avoided by the slipping of the "friction clutch 16.

In addition to permitting switch points to be forced over without injury when the switch is trailed, it is desirable to return the switch points automatically to their former position in correspondence with the control lever; but this should not be done until after, the cars trailing the switch have all passed, otherwise there would be a reciprocation of the switch points, with resultant wear and tear, as each pair of wheels or truck passes over the switch points. All this is taken care of by the action of the track relay T'by cutting oil' the supply of power to the switch machine, and by the fact that, whenever the switch machine has been forced into a position out of correspondence with the controlling lcver, conditions areset up supplying current to the switch machine and restoring it"to its "former position in correspondence with the lever.

Explaining in detail, assume that the switch machine and lever are in the normal position shown in, Fig. 1. When the switch is trailed and the points forced over, the con: tacts of the pole changer P are shifted to the other extreme position. So long as a car is present on the detector track circuit, the track relay T is deenergized so that no current canbe supplied'to the switch machine. As soon as'the car or train trailing the switch, however, has-left the detector track circuit and the track relay T picks up, current is supplied to the motor M of the switch machine to restore the switch points back to their former normal position. Remembering that the lever is in the normal position shown, and that the contacts of the pole changer P are reversed, this operating circuit may be read ily traced as follows :-Commencing at the battery B, wires 120 and 121, high resistance winding 70 of relay CR, wire 122, contact finger 123, track relay T reversed, wires 170, 125 and 126, low resistance windin 71, wires 127 and 171, contact fingers 172 o the lever now normal, wires 173 and 144, contact springs 143, .pole changer contacts being re.- versed, wires 142 and 133, armature A, wires 132 and 149, contact springs 148 and 135, wire 136, field F, and wires 137 and 138 back to the battery B.

Thus, regardless of the length of the train trailing the switch, the switch points may be forced or thrown over without injury, held there until the train has entirely passed, and are then automatically returned to their former position in correspondence with the lever, assuming of course that the lever has not been changed in the meantime. Incidentally, the indications of the pot signal S are automatically changedas the switch is trailed; but since the track circuit is occupied and also because the switch is out of correspondence with the lever, neither of the indicator lights nor '1' is lighted.

qrcnt any manner. This safety device assures that the erson manually cranking a machinewill -not e'iiniured in case power should be unex- Mamual operati0n.-It is extremely important for classification yards that there should be no interruptions; and if there is any failureof power, or other trouble with any switch, it'should be possible to operate that switch by hand. As previously explained, a switch machine of this invention includes provisions for its operation by a suitable hand crank 01'' the like. However, before a hand crankcan be inserted, the angle lever 41 Fig. 2) must be shifted to allow'the crank to e inserted,'and in so doing the long contact finger 135 is lifted to break the common return connection to the battery B throu h the field F, thereby preventing curi 'rom reaching the switch machine in pectedly"applied to the switch machine for any reason, and also makes it certain that a switch machine once manually placed in a given position willremain there and will not be displaced until, b removal of the crank and re-positioning o the angle lever 41, the switch has been deliberately put back under power operation.

From the foregoing explanation, it can be seen that this invention provides a simple and eflicient system for operating by power from a central control point any desired number of distant switches in a classification or hump yard. For simplicity of explanation and description, no attempt has been made to show or explain the various well known expedients of the art that mightbe used in practice in addition to and 1n conjunction with the particular devices hereinbefore described. For instance, various signals, in addition to the pot signals S, may be located throughout the yard and their indications controlled from the tower for the guidance of the engineers and the train crew. Such signals, and other expedients, may be applied to and used in connection with a system of this invention without modifying its functions or operation. Similarly, the particular devices and the circuit organization herein disclosed is susceptible of modification and adaptation in practice without altering the functions or scheme of operation. I desire to have it understood, therefore, that my invention is not limited to the particular-embodiment shown and described, but embraces all equivalent means and various sub-combinations and re-organizations, coming within the scope of the appended claims.

What I claim is 1. Inan interlocking system, the combination with a main track and a branch track of a switch whereby traflic may be directed to said branch track or directly ahead on said main track, and power operated means for operating said switch including a switch point operating bar having a transverse slot therein, a pivotally mounted gear sector and a pivotally and slidably mounted rod engaging said sector, means movable with said rod and said sector engaging said slot, and a spring engaging said rod, whereby said switch is biased toward either of its extreme positions.

'2. In an interlocking system, the combination with a main and a branch track, a track switch whereby traflic may be directed to said branch track or directly ahead to said main track, and power operated means for operating said track switch to either the open or the closed position, said power op} erated means including a gear sector, for operating said track switch, a pivotally mounted rod engaging said gear sector and biased toward said gear sector for urging said gear sector in either of two extreme positions from an intermediate position, and means for indicating the position of said gear sector.

3. In an interlocking system, the combination with a main track and a siding, of a switch connecting said main track and sid ing, andpower operated means for operating said switch which will allow said switch to be trailed by a train and if so trailed will complete the stroke of the switch to the trailed position and will hold it there, said last mentioned means also including means for returning the switch points to their previous position only effective it said train has passed completely 0d of said switch.

4. Means for operating switches for railroads comprising, a switch machine having a switch bar biased toward each extreme position from points on the corres onding side of its neutral position, a motor or operating said bar having'an armature and a field winding, and means for connecting the field winding and the armature of said motor in a circuit of low resistance during a portion of the stroke of said bar for electro-dynamically brakin said motor.

5. cans for operating switches for railways comprising, a switch machine having a switch bar biased toward each extreme position from points on the corresponding side of its neutral position, a motor for operatin said bar, and a manually operable doublethrow switch of the quick-acting snap type for controlling said motor, said manually operable double-throw switch being so constructed that it cannot be manually held in an intermediate position, in which power is cut off of said motor, thereby preventing the operator accidently leaving the switch machine in the neutral position.

6. Means for operating switches for railways comprising, a switch machine having a switch bar biased toward each extreme position from points on the corresponding side of its neutral position, a motor for operating said bar, and a quick acting manually operable double-throw switch for controlling said motor, said manually operable switch being constructed so that it can not be held in an intermediate position.

7. Traflic controlling apparatus for rail ways comprising, a track switch, a switch bar operatively connected to said track switch.

and biased toward one or the other extreme positlon from points on the corresponding 1 side of the neutral position depending on whether it is on one or the other side of such neutral position, a motor for operating said bar in either direction, and a friction slip clutch between said motor and said bar for allowing relative movement between said motor and said bar for extreme forces existing therebet-ween, whereby said track switch may be operated by a train trailing the track switch without operation of said motor and whereby the bias of said switch bar maintains the track switch in the trailed position until again operated by said motor.

8. A switch system comprising, the usual main and branch track and a detector track circuit therefor a three position indicating means controlled by said detector track circuit for giving an indication depending on the presence and the polarity of potential across the detector track circuit, a switch connecting said main track and branch track, a power operated switch machine for operating said switch, means for initiating operation of said switch machine only operative if said detector track circuit is unoccupied, and means for applying energy to said detector track circuit having a relative polarity depending on the position of said switch.

9. A switching system comprising, the usual main track and branch track and a detector track circuit therefor, a switch adapted to connect said main track and branch track, a switch machine for operating said switch constructed so that if said switch 7, is thrown over beyond the intermediate posionly operable if said detector track circuit is unoccupied, said switch machine being constructed so that it will only be operated to a position corresponding to that of a sultable manually controllable lever providing said track circuit is unoccupied, whereby it said switch is trailed by a train it will be thrown over and maintained in such position until the detector track circuit is again cleared, after which it will automatically be returned to a position corresponding to that of the control lever.

10. A switch machine comprisin a casing, a gear sector having an exten ing arm pivotally supported in said casing, means comprising a rod having one end slida'bly and pivotally supported in said casing and having the other end pivotally connected to said arm, a coiled compression spring on said rod for biasing said rod toward said gear sector, a switch bar operatively connected to said gear sector, and a motor operatively connected to said sector.

11. In a switch machine, the combination with a switch bar movable to two extreme positions for operating a railway track switch to two extreme positions, a motor for operating said switch bar, a normal circuit which if closed operates said motor in one direction, a reverse circuit which if closed operates said motor in the reverse direction, a doublethrow switch which if in one extreme position closes said normal circuit and which if in the other extreme position closes said reverse circuit, spring actuated toggle means for holding said double-throw switch in the extreme position to which it was last operated, and means operated synchronously with said switch bar for operating said doublethrow switch to one extreme position when the switch bar assumes one extreme position and operating it to the other extreme position when the switch bar assumes the other extreme position, whereby said double-throw switch is firmly held into the proper extreme position during the main portion of the operating stroke when the switch bar is operated by the motor.

, ways comprising, a throw bar connected to the points ofa track switch, an electric motor for operating said throw bar, compression spring means for biasing said throw bar toward each of its extreme positions from points on corresponding sides of its neutralposition, and an electric switch, operated in accordance with the position of said throw bar and acting to de-energize said motor and to .connect its windings in a circuit of low resistance after said throw bar has been moved past its neutral position, whereby the motion of said throw bar due to the action of said compression spring means may be gradually opposed and reduced.

14. In an interlocking system, in combination with a main track, a branch track, a track switch for directing trafiic along the main track or to the branch track, a power operated means for operating the track switch including a motor, and a track relay, a double wound relay having a high resistance coil and a low resistance coil, and means for completing a motor circuit with the track relay contact andthe high and low resistance coils of the double wound relay in series.

15. In an interlockin system, in combination with a main trac a branch track, a track switch for directing traflic along the main track or to the branch track, a power operated means for operating the track switch including a motor, and a track relay, a double wound relay having a high resistance coil and a low resistance coil, and means for completing a motor circuit with the track relay contact and the high and low resistance coils of the double wound relay in series, for picking up the contact finger of the double wound relay and thereby shunting the high resistance coil and track relay contact out of said circuit.

In testimony whereof I hereby afiix my signature.

WINTHROP K. HOWE.

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