US1548352A - Automatic electrically-controlled track switch - Google Patents

Description

Aug. 4, 1925; 1,548,352

R. V. COLLINS AUTOMATIC ELECTRICALLY CONTROLLED TRACK SWITCH Filed April 5. 1923 3 Sheets-Sheet 1 lnv e nTor.

Q 1, Roy GOHinS Aug. 4, 1925. 1,548,352

R. v. COLLINS AUTOMATIC ELECTRICALLY CONTROLLED TRACK SWITCH Filed April 5, 1923- Sheets-Sheet 2 Fig.2.

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Roy VQCollins b mwpm v Aflys.

Aug. 4, 1.925. 1,548,352

1R. v. COLLINS AUTOMATIC ELECTRICALLY CONTROLLED TRACK SWITCH Filed A ril's. i925 s sheet-she et- 3 F1 g3- F1 g. 4.

lnvenTo r'. R0 V. CuHi ns byizmdwkm Aflys.

Patented 192.5,

UNlTED STATES T FFQE.

ROY V. COLLINS, OF NEWTONVILLE, MASSACHUSETTS, ASSIGNOR T0 COLLINS SWITCH & SIGNAL COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC ELECTRICALLY CONTROLLED TRACK SWITCH.

Application filed April 3, 1923.

T 0 all whom it may concern Be it known that I, ROY V. COLLINs, a citizen of the United States, and resident of Newtonville, county of Middlesex, State of Massachusetts, have invented an Improvement in Automatic Electrically-Controlled Track Switches, of which the following description, in connection with the accompanying drawing, is a specification, like charac ters on the drawing representing like parts.

This invention relates to a track switch for use in electric car lines and particularly to an electrically-actuated switch which is automatically controlled by the movement of the trolley past a predetermined point. These electrically-actuated switch devices usually include a switch-throwing magnet or solenoid by which the switch is thrown, a suitable contactor associated with the trolley wire and adapted to be engaged by the trolley wheel and means whereby the engagement of the contactor by the trolley wheel will operate to close the circuit of the switchthrowing magnet.

Qne of the objects of my present invention is to provide a novel construction by which when the circuit for the switch-throwing magnet has been closed by the engagement of the trolley wheel with the contactor, said circuit will remain closed for a predetermined length of time and then will be automatically opened regardless of the length of time with which the trolley wheel engages the contactor.

The current which is necessary to operate the switch-throwing magnet is a relatively heavy current and an advantage of this construction which involves a timing element for timing the length of time which said switch-throwing circuit shall be closed is that it ensures that said circuit will always be closed long enough to properly actuate the switch-throwing magnet and then will be automatically opened without regard to the position of the trolley wheel with rela tion to the contactor. The automatic opening of the circuit after it has been closed for a suiiicient length of time to actuate the switch prevents any possibility of overheating the switch-throwing magnet due to the heavy current remaining thereon unnecessarily after the magnet has performed its function.

The circuit of the switch-throwing magnet Serial No. 629,693.

is closed by a timing relay which has the timing element associated therewith and the circuit for the timing relay is arranged so that it will be closed when the trolley wheel engages the contactor. The closing of the timing relay circuit for an instant onl is sufficient to energize said relay and to c osethe circuit for the switch-throwing magnet, and the timing element associated with the timing relay maintains the circuit for the switch-throwing magnet closed for the appropriate length of time regardless of the length of time that the circuit for the timing relay is closed and, therefore, even if the trolley car should stop with its trolley in engagement with the contactor yet the circuit for the switch-throwing magnet would be opened after said magnet had performed its function.

My invention also comprehends a construction by which the switch-throwing magnet is prevented from being operated a second time until the car which has operated it the first time has passed beyond the switch, this construction making it impossible for a car which is following the car which has thrown the switch from dis-arranging the switch until said car has passed the switch.

In order to give an understanding of the now be described after which the novel fea-' tures will be pointed out in the appended claims.

Fig. 1 is a view in the nature of a wiring diagram illustrating the wiring connection of my improved apparatus;

Fig. 2 is a view showing the parts of the apparatus enclosed in a casing, the cover and the casing being removed to better illustrate the device;'

Figs. 3 and 4c are detail views of the timing element showing the parts in different posi tion;

Fig. 5 is a. view of the contactor;

Fig. 6 is an end view of the contactor;

Fig. 7 is a view of the unlocking contactor;

Fig. 8 is a section on the line 88, Fig. 5;

Fig. 9 is a fragmentary plan view of the unlocking contactor shown in Fig. 7.

In Fig. 1 of the drawings 1 indicates the trolley wire and 2 indicates the track switch which is actuated by the two solenoids or which of the two magnets 3 and 4, the solenoid 3 operating to nets 3 and 4, which will be more fully hereinafter described, are closed'by a timing relay indicated at 6 and the circuit for this relay is closed thereby to make it operative by the trolley wheel 7 ota trolley car engaging a contactor, shown generally at 8, whichis associated with the trolley wire 1. The cont-actql herein shown vis in the form of two slices or contact strips 9 that are situated either side of the trolley wire i and are .so arranged that as the trolley wheel passes the contactor the flanges of thetrolley wheel will engage the contacts 9 as shown in, Fig. 6 and in doing so will be withdrawn from engagement with the trolley wire 1. The, trolley wheel, therefore, bridgesthe contacts 9 while in engagement withthe contactor. V

The .two shoes 9 are. showiras suspended from two strips 10, of. wood or other insulating naterial, said strips in turn beingsupported by the trolley cars, 11. These shoes or contacts 9 are shownas having extensions 99 rising therefrom, each eXtension having on its upper end a seat 98 resting against the under side of the two wooden strips 10. These extensions 99 are secured to the wooden strips by rbolts 9? which extend between tllQWOQCl'Gll strips and through clamping plates 96 which overliesaid wooden strips, Th'econtacts or shoes 9 arethns insnlated frorn the trolley wire and from each other. These contactstrips in the circnitof the timing relay 6, said circuit being normally open between said contacts butbeing closed when the trolley wheel 7 bridges the contacts, as shown in Fig. 6.. This circuit of the timing relay 6 is herein 'illus;

tr ated as follows It consists ota wire connection 12 connected to the trolley wire 1 at 13 and leadingto one blade 1 1- of a threepole switch 15. wireconnectionlfi leading to a selective relay 17, which will be hereinafter described, and which operat'esto select switch-thrpwing magnets 23 and 4 shall be operated, a wire connec ion 18 leading from the magnet 1.7 to a binding post 19,,wire connection 20 leading' to one of the contact strips 9 through the blade 21 of the three-pole switch 15, a wire connection 22 leading from the other contact strip 9 through the third blade 23 of the three pole switch 15, wire connection Q t-l'eading from said blade 23 to the timing relay 6, (said wire, connection 24 being shown as having "a fuse 25 therein) and wire connection 26 which leads to the ground at 2/7 and is provided with a suitable resistance 28 therein. From the above it will be seen that when the three-pole switch 15 is closed the circuit of the relay 6 will be normally open bet-ween the two contact strips 9 but when the trolley wheel 7 engages said strips 9 and bridges the latter, as shown in Fig. 6, the abovedescribed circuit through the timing relay 6 will be completed and the latter will be energized. lVhen the trolley-wheel engages the contact strips 9 it is separated from the trolley wire 1 so that no current will pass directly from the trolley wire to the trolley wheel and, therefore, the current can only take the path above outlined which includes the timing relay 6. i i i As stated above the energizing of the timing relay 6 by the engagement of the trolley wheel with the contactor 8 serves to close the circuitthrough one of the switch-throwing); solenoids 3 or 4. This relay 6 is provided with an armature 29 which is pivotallymounted at 301' A contact arm 31 is also pivoted at 30 co-axially with the armature 29 and carries a bridgingcontact32 Fig. 1, with the bridging contact 32 sep arated from the contacts"33,3a but when the timing relay 6 energizeclthe armature 29 is attracted. thereby swinging the bridging contact into engagement with the contacts 33, 34; and closing the-circuit of the switch-throwing; magnet.

The timing relay has associated therewith timing means for determining the length of time that the bridging contact 32 will remain in engagement with the contacts 33,

34-, said timing mechanism being connet, therefore. comprises the 'wire conne'm tion 12. switch blade 14, wire connection 16,-the'w1nd1ngs to the selectlve relay 17.

f wire connection 18 to the binding post 19,

wire connection 35 leading from the binding post 19 to the stick relay 36. which -w1-ll be hereinafter described, (said wire connection 35 having the fuse 37) windings of stick relay 36. wire connection 38 leading to the contact 34, wire connection 39 load ing from the contact 33 to the armature 40 of the selective relay 17 and either corn tact tl and wire connection 42 leading; to the switch-throwing; solenoid 4 or contact 43 and wire connection 44 leading to swi-tcl ithrowing solenoid 3, and from oneor the other ofsaid switch-throwing solenoids lo the ground at 4:5. The armature 40.01? the selective relay 17 is adapted to engage either of the contacts 41 or 43 and the position of this armature is determined by the selective relay 17. When the selective re lay 17 is not operative then the armature 40 engages the contact 41 and the switchthrowing solenoid 4 is in the circuit while when the selective relay 17 is operative the armature 40 is raised into engagement with the contact 43 so that the switch-throwing solenoid 3 is in the circuit.

Means are provided, which will be hereinafter described, by which the motorman on the electric car can control the operation of the selective relay and thereby determine which one of the switch-throwing solenoids 3 or 4 will be energized.

The engagement of the trolley wheel with the contactor 8, therefore, energizes the timing relay 6 and causes the latter to operate to close the circuit through one or the other of the switch-throwing solenoids by means of the bridging contact 32 engaging the contacts 33, 34.

The timing relay 6, the selective relay 17, the stick relay 36, fuses 25, 37 and the resistance 28 are all preferably mounted in a suitable housing 46, as illustrated in Fig. 2. The timing mechanism which is associated with the timing relay comprises a lever 47 pivotally mounted co-axially with the armature 29 but independently thereof, said lever carrying at its opposite ends two weights 48, 49, the weight 49 being slightly heavier than the weight 48 so that it will overbalance the latter. The arm 31 carrying the bridging contact 32 is also pivotally mounted co-axially with the armature but independently thereof and means are provided whereby normally the arm 31 is latched to the armature so that when the armature is drawn downwardly the arm 31 will be swung forwardly to close the contacts 33, 34. This latching means com prises a latch 50 which is pivotally mount ed at 51 on an extension 52 of the armature 29, said latch normally engaging a lug or projection 53 formed on the arm 31 so that when the armature 24 is swung downwardly into the position shown in Fig. 3, the latch 50 will operate to swing the arm 31 forwardly.

The latch is constructed so that it is antomatically released from the lug 53 when the arm 31 has been carried into a positionto bridge the contacts 33, 34 and this is accomplished by providing the latch with a tail 54 which engages an adjustable stop screw 55 when the armature is in its lowered position shown in Fig. 3. The engagement of the tail 54 with the stop screw rocks the latch thereby disengaging it from the lug 53 as shown in Fig. 3.

The weighted lever 47 with its weights 48, 49 constitute the timing element which governs the time during which the circuit of the switch-throwing magnet will be closed at the contacts 33, 34. This lever 47 is provided with a lug 56 which normally engages the projection 53 on the arm 31, said lug being held in engagement with the projection because the weight 49 is greater than the weight 48. Therefore when the armature 24 is drawn downwardly, as shown in Fig. 3, the movement of the arm 31 is transmitted to the lever 47 through the lug 56, so that during the downward movement of the armature 24, said armature and the arm 31 and lever 47 turn as a unit about the pivotal point 30. This downward movement of the armature will, of course, be a rapid one, and since the lever 47 is free to turn on the pivot 30 the momentum of the lever and the weights will cause said lever to continue turning after the armature has reached the limit of its downward movement as shown in Fig. 3 so that the lug 56 on the lever 47 will be separated from the projection 53. The lever will continue its forward turn ing movement after the contacts 33, 34 are closed until the preponderance of the weight 49 over the weight 48 overcomes the momentum of the weighted lever and begins to restore the lever to its normal position. As soon as the momentum of the lever 47 has thus been overcome the heavier weight 49 begins to turn the lever 47 back to its normal position and during this return movement the lug 56 will enga e the projection 53 on the arm 31 and carry said arm backwardly into the position shown in Fig. 4, this being permitted because of the fact that the latch 50 is released from the projection 53 as shown in Fig. 3. It might be stated that when the arm 31 is in av position in which the contact 32 is bridging the contacts 33, 34, said arm will be held by gravity in its position until it is restored to its initial position by the return weight-ed lever 47.

The length of time, therefore, which the circuit of the switch-throwing magnet will be closed depenos on the time required for the greater weight 49 to absorb the energy of momentum of the differential weighted lever 47 and return said lever into a position to engage the projection 53 on the arm 31. The parts are so constructed that the time thus required is sufiicient for the switchthrowing magnet to accomplish its function.

The construction of this timing mechanism is such that the circuit of the switchthrowing magnet will be opened automatically after the predetermined time regardless of whether the timing relay 6 continues to be energized or not, for as soon as the armature has been drawn down to the solenoid as shown in Fig. 3 the arm 31 will be unlatched from the armature and it is thus free to return to its normal position, even though the armature remains in the low ered position.

The advantage of this construction is that it obviates any danger of injury to either of the switch-throwing solenoids 3 or 4.- by reason of the current remaining thereon unduly long. The current which is used in these switch-throwing magnets is a relatively heavy current suitable for doing the heavy work of throwing the switch 2 and it would be detrimental to the solenoids 3 and 4 it this heavy current remained on them unduly long. The timing. mechanism prevents this and ensures that the circuit of the switchthrowing magnet will be opened after the magnet has done its work even though the timing relay 6 remains energized, as might occur if the trolley car should stop with the trolley wheel in engagement with the contact strips 9. Furthermore the timing mechanism will function to ensure the closing of the circuit of the switch-throwing magnet and then to open the circuit after a predetermined length of time even though the timing, relay 6 is energized for a very short period of time which of itself would be insuificient to enable the switch-throwing solenoids to accomplish their function. If the timing relay 6 is energized for even a very brief period it will operate to attract its armature and thereby close the circuit of the switch-throwing magnet at the contacts 33, 34 and even if the timing relay 6 should be immediately deenergized as soon as the circuit of the switch-throwing magnet is closed yet the timing mechanism will maintain the switch closed for the required predetermined length of time. By reason of this it is possibleto use a relatively short contactor 8 which is only long enough to ensure that the timing relay 6 will be energized. The use of a short contactor is advantageous because it reduces the weight which is supported by the trolley wire.

I have heretofore referred to the relay 17 as the selective relay which functions to select which of the two switch-throwing magnets 3 or 4 shall be operated. The operation of this selective relay is controlled by. the motor-man of the car and he renders it operative or non-operative by keeping the current on the motor of the car or shutting it off as the trolley wheelengages the contactor 8.

It will he noted that the winding of the selective relay 17 is in the portion of the relay circuit between the point where the wire 12 taps the trolley wire 1 at 13 and the contactor 8. If the current is shut off from the car motor during the time that the trolley wheel is in engagement with the contactor 8 then the only current which will flow through the wire connections 12, 16 and the selective relay 17 is the current which passes through the timing relay 6 and such current as is used for the lights and heaters of the car, The selective relay 17 is so wound that this current of itself will not attract the armature lOand hence if the current is shut off from the car motor while the trolley is in engagement with the contactor the selective relay 17 will 'be nonoperative and its armature will remain in contact with the contacttl thusplacing the switclrthrowing solenoid 1 in the circuit. If, however, the controller of the trolley car is positioned so as to keep the current on the car motor when the trolley wheel passes the contactor 8 then since the contactor separates the trolley wheel from the the trolley wire the current for the car motor will be taken from the trolley wire through wire connections 12, 16 and theselective relay 17 and thence through the wire connections 18. and 20 to the cont-actor and from the contactor to the trolley wheel and thence to the motor. At the same time the bridging of the contact strips 9'will allow current to flow through the timing relay 6 so that when the current is on the car motor the selective relay 17 has passing there through not only the current necessary to.

operate the timing relay 6 and the lights and heater of the car but also the current taken by the motor of the car. This selective relay is so wound that this heavier current is suiiicient to raise: the armature 40 against the contact 43 and thus close the branch circuit 4 1 through the switclrthrowing solenoid 3.

Therefore, if the motorman wishes to ac tuate the switch point 2 by the solenoid 4 he will shut the current oil from the motor while passing the contactor 8 thus causing the selective relay 17 to remain inactive so that the current will be sent through the branch 12 of the switch-throwing solenoid 1. On the other hand ii he wishes to actuate the-switchby the switclrthrowing solenoid 3 he will leave the current on the motor while passing the contactor 8 and this will render the selective relay 17 operative to close. the branch circuit at through said switch-throwing solenoid 3. lVith this ar rangement, therefore, the motorman will leave the current on the motor or shut it off from the motor when passing the contactor 8 depending on which way he wishes the switch point 2 to direct the car.

I have also provided herein means whereby after the timing relay 6 has operated to close the circuit through the switch-throwingsolenoid, said relay will be held inoperative for further action until after the car which actuated it has passed the switch point. The purpose of this is to provide means which will prevent a second car which is closely following a first car from throwing the switch point until after the first car has passed the switch. Otherwise, it might be possible for the second car to follow the first car so. closely that said second car would throw the switch before the rear wheels of the first car had passed the latter.

This end is accomplished by providing means whereby when the relay 6 is energized by a car engaging the contactor 8 said relay will remain energized until after the car has passed the switch point 2.

The armature 29 of the timing relay is provided with an extension 57 which carries an insulated bridging contact adapted to bridge two contacts 58, 59, the contact 59 being connected by a wire connection 60 to the wire connection 24 on the input side of the timing relay 6 and the contact 58 being connected by a wire connection 61 to a contact 62 which is normally engaged by a contact 63 carried by a contactor member 6 that is pivoted at 65 to a frame 67 that is supported by twoposts 66 rising from the trolley wire 1. This frame 67 is forked at one end and a cross bar 68 of wood or other insulating material is supported by said forked end. The contact 62 is carried by this cross bar 68 so that said contact is insu- ;be established through the timing relay 6 from the trolley wire through the member 64, contacts 63, 62, circuit wire 61, contacts 58, 59 wire connection 60, thence to the timing relay 6, wire connection 26, resistance 28 to the ground 27. The energizing of the relay 6 thus closes its circuit at the contacts 58, 59 and said circuit will remain closed until the car engages the contactor 64 and opens the circuit at the contacts 62, 63.

This contact 64 is so situated relative to the switch point 2 that the trolley wheel will not open the circuit until after the car has passed the switch point 2.

\Vith this construction, therefore, when the relay 6 has been energized by the trolley wheel bridging the contact strips 9 said relay will remain energized thus holding its armature 29 depressed until after the car has passed the switch point 2, and has opened the circuit 61 by separating the contacts 62, 63. Hence any following car cannot actuate the timing relay until the first car has safely passed the switch.

I have heretofore referred to the stick relay 36 and the function of this is to ensure should have meanwhile passed off from the contactor 8, which may be relatively short.

It will be noted that the current passing through the stick relay 36 is that which passes through the switch-throwing solenoid. If the selective relay 17 has been rendered operative to raise the armature 40 by reason of the fact that the motorman has left the current on the car motor while passing the contactor 8 as above described, it will be observed that as soon as the trolley wheel passes olf from the contactor 8 the heavy current going to the car motor will be withdrawn from the selective relay 17, and the latter will thus become inoperative to hold the armature 4O raised, so that unless something were provided to hold the armature 40 raised it might transpire that the current would be cut off from the switch-throwing magnet 3 before the latter had completed its switch-throwing function. This is prevented, however, by the stick relay 36 because as soon as the circuit of the switchthrowing magnet is closed a current will be carried through the stick relay 36 and while this current is insufiicient to raise the armature 40 yet it is suiiicient to hold the armature %0 in its raised position even though the motor-operating current is shut off. Hence the circuit for the switch-throwing magnet will remain closed through the switch-throwing solenoid 3 until the circuit is opened at the contacts 33, 34: by the timing relay.

I claim.

1. In an electrically-controlled track switch, the combination with a switchthrowing solenoid, of a normally-open circuit therefor, a timing relay, means to energize said relay by a passing car, and timing means operated by said relay to close the circuit of the switch-throwing solenoid and to maintain said circuit closed for a predetermined length of time regardless of the length of time during which the timing relay is energized.

2. In a device of the class described, the combination with a switch-throwing solenoid of a normally-open circuit therefor, electro-controlled timing means rendered operative by a passing car, and operating to close the circuit of the switch-throwing solenoid and maintain the same closed for a predetermined length of time and then to open said circuit at the termination of said predetermined length of time regardless of whether the timing relay is still energized or not.

3. In a device of the class described, the

combination with aswitch-throwing solenoid, of a normally-open circuit therefor, a timing relay, means to energize the relay by a passing car, means to close the circuit of the track-throwing solenoid when the relay is energized and an inertla devlce to open said circuit after a predetermined length of time. i v

4. In a device of the class described, the combination with a switch-throwing solenoid, of a normally-open circuit therefor, a timing relay, means to energize the relay by a passing car, means to close the circuit of the track-throwing solenoid When the relay is energized and an inertia device to open said circuit after a predetermined length o'ftime regardless of Whether the relay. is energized or not. i

5. In a device of the class described, the combination \vitl'r a sn'*itcl1-throWing solenoid, of a normally-open circuit therefor, a contact for closing the circuit, a timing relay, means rendered operative by energizing the relay to move the contactinto position to close said circuit, and a mechanical timing device for opening the circuit again after a predetermined time Without regard to Whether the til'ning relay is still energized or'not.

6. In a device of the class described, the combination with a switch-throwing solenoid, of a normally-opeii circuit therefor, a contact for closingthe circuit, a timing relay, means rendered operative by energizing the relay to more the contact into position to close said circuit, and an inertia device to open the circuit again aftera predetermined length of time.

7. In a device of of a normally-open circuit therefor, atiming' mechanismfor closing said circuit and, maintain-mg itv closed for a predeterm ned length of time, said mechanism comprising a=magnet, meanstoenergize it by a passingv car, a contac'tbywwhich the'circu'it is closed, an armature'fonthe magnet, means normal- 1y connecting the armature and contact wherebylwhen themag'netis energized the contact is actuated'to close the circuit ofthe sr'vitcltthrow'ing"magnet, and an inertia device for operating the contact to open said circuit after a predetermined length of t e 7 A V 8, Ina device of" the class described, the combhration. yvith a switch-throwing magnet,

of anormally-opencircuit there-for, a timthe are described, thecombination with a switch-throwing mag'net,

mea er timing mechanism for closing said circuit and maintaining it closed for a predetermined length of time, said mechanism com prising a magnet, means to energlze 1t by a passing car, a contact by which the circuit is closed, an armature for the magnet, a latch length of time, said mechanism comprising a n'ia'gnet, means to energize itby a passing car, a contact by which the circuit is closed, an arir'iature for the magnet, a latch normal- 1y connecting the armature and contact whereby the contact is closed When-the arma-i tru'e is attracted, means for rinla'tching the armature from thecontact when the latter isfclosed, and an inertia device to open the cdntactjafter a predetermined-length of time.

11. In a device of theclassdescrihed, the

coinbinatihii with "tra cli switch, of a sole noid for operating" thesaine, anonnally open ci'rcui't" therefor, a timing relay for closing said circuit, means to energize the, relay by a arr approachihg the tracltsivitch and to maintain the relay energized until the car has passed s'a'idjtr'a'cjk Sea ii, andmeans'to openthe circuit of" the switch operating sole noid" at; a p'redeterniiiid interval after it has beeridt di v j m L 12L a devic'eoif the classdescribed, the combination with track switch, of la. solenoid for operating the same, a normallymg said circuit, means to energize the relay by'a car approaching ,thetrfack switcha nd to maintain nie,1- e1ity; ener 1zed until the car has passedsaidtraokswitch, end-an inertia device "to open" the" circuitof the switch operating solenoid at a predetermined time afterit hasbeen closefd H y i 13. I In jajdev-icelof the cliass described, the combination with. a ittack sivitch, of a solenoid for operating 'thefsam, a normallyopen circuit for thefsolenoid, atiming' relay for closingj said cifcuit, means -to energize thefrel'ay acar approaching the track switch and to maintainsaid relay energized until thecair' haskp-as'sed the tracl; switch,

..z- 1. ,.i 1 and a t m ng device set in operatlonby the clhsing of "the solenoid'lcircuit and joperating 7.74 vwl H, ,i zl i to open said, circint ata predetermmed time intert'al'atter itfhiisb'efen closed.

14. Ina d-eyiceof thfe classdescrihed, the combination with a track switch, of a solenoid for op"crating; ma ma, normallyopen circuit for thesole'noid, a timing relay tor closing said circuit, means to energize the relay by a car approaching the track switch and to maintain said relay energized until the car has passed the track switch, and an inertia device set in motion by the closing of the solenoid circuit and operating to open said circuit after a prede termined length of time.

15. In a device of the class described, the combination with a track switch, of a solenoid for operating the same, a normallyopen circuit therefor, a timing relay for closing the circuit, a circuit through which said relay is energized, means to close the circuit by a car approaching the switch and to open the circuit of the switch-operating solenoid after it has been closed for a predetermined time interval and independently of the opening of the relay circuit.

16. In a device of the class described, the combination with a trolley wire, of two sep arate contact strips associated therewith and arranged to beengaged by the flanges of a passing trolley wheel, said strips eing so located that as the trolley wheel passes over them said wheel is separated from the trolley wire, a switch-throwing solenoid having a normally-open circuit, a relay for closing said circuit, a circuit for the relay including the contact strips, whereby when a trolley wheel. engages said contact strips the relay will be energized, and inertia means for opening the circuit of the switch-throwing magnet after a predetermined time interval.

17. In a device of the class described, the combination with two switch-throwing magnets and normally-open circuits therefor, of

a timing relay for closing said circuits,

means to energize said relay by a passing car, inertia means to open the circuit of the switch-throwing magnet after a predetermined time interval, and a selective magnet for selecting which of the two switch-throwing magnets shall be rendered operative.

18. In a device of the class described, the combination with a trolley wire, of two s itch-throwing magnets, and normallyopen circuits therefor, a timing relay for closing said circuits, a contactor associatedwith the trolley wire, means rendered operative by 'a trolley wheel engaging the con tactor to energize the timing relay, a selective relay for selecting which of the two switch-throwing magnets shall be rendered operative by the actuation of the timing relay, and inertia means to open the circuit of the switch-throwing magnet after a predetermined time interval.

19. In a device of the class described, the combination with a trolley wire, of two switch-throwing solenoids, a normally-open circuit having a branch leading to each solenoid, a selective relay normally closing one branch, a contactor associated with the trolley wire, a timing relay for closing the cir cuit of the switch-throwing solenoids, a cira trolley car engaging the contactor, said selective relay being in said circuit between the timing relay and the source of electrical energy and an inertia device to open the circuit oi the switclrthrowing solenoid after a piedetermincd time interval.

20. In a device of the class described, the combination with a trolley wire, of two contactor strips associated therewith but insulated therel roi'n, and situated to be engaged by the flanges of a passing troll y wheel and to separate the trolley wheel from the trolley wire, a circuit connection from one contact strip to the trolley wire, a circuit connection from the other contact strip to the ground, a switch-throwing solenoid having a normally-opcn circuit, a rela for closing said circuit located in the circuit conneci 16" leading to the ground and an inertia t ng device to open said circuit after a predetermined time interval.

21. In device of the class described, the combination with a trolley wire, of two contact strips associated therewith but insulated therefrom, and situated to be engaged by the flanges of a passing trolley wheel and to separate the trolley wheel from the trolley wire, a circuit connection from one contact strip to the trolley wire, a circuit con nection from the other contact strip to the ground, a switch-throwing magnet having a normally-open circuit, a timing relay for closing said circuit located in the circuit connection leading to the ground whereby the timing relay is energized when a trolley wheel engages the contact strips, and means associated with said timing relay to open the circuit of the switch-throwing magnet after a predetermined time interval independently of the opening of the circuit of the timing relay.

22. In a device of the class described, the combination with a trolley wire, of two contact strips associated therewith but insulated therefrom and situated to be engaged by the flanges of a passing wheel and to separate the trolley wheel from the trolley wire, two switch-throwing magnets, a normally-open circuit therefor, a relay for closing said circuit, a circuit connection between one contact strip and the trolley wire, a circuit connection between-the other contact strip and the ground, the latter circuit connection including the relay, a selective relay in the first-named circuit connection and operative to select which of the two switch-throwing magnets shall be rendered operative and an inertia device to open the circuit of the switch-throwing magnet after a predetermined time interval.

23. In a device of the class described, the combination with a track switch, of a switch throwing solenoid, a circuit for the solenoid normally openiin two places, means rendered 4 for a predetermined length. of time and .then' operative by a car approaching the switch to close the circuit at one place and to maintain said circuit closed for a predetermined length of time, means also rendered operative by a car approaching the switch to close said circuit at the other place, and a stick coil in the circuit of the switchthrowing solenoid for holding said circuit closed at the latter place so long as said circuit is closed at the first-named place.

24. In a device of the class described, the

combination with a track switch, of two switch-throwing solenoids, a normally-open circuit therefor, of a timing relay for closing said circuit and maintaining it closed:

for a predetermined length of time, a selec-- tive relay for determining which of the two switch-throwing solenoids is to be connected in said circuit, and a sticl: coil in said circuit for maintaining the selective relay operative so long as the circuit of the switch-throwing solenoid is closed.

25. In a device ot'the classdescribed,the combination with a track switch, of two switch-throwing solenoids and a normallyopen circuit therefor, timing means rendered operative 'bya car approaching said switch to close said circuit and maintain it closed toopen it, a selective relay for determining which of the two switch-throwing solenoids shall be operative, means to energize said relay by a car approaching the switch, and

a stick coil in the circuit of the switchthrowing magnet for maintaining the seleotive relay operative so long as said circuit is closed. i.

26. In a device of the class described, the combination with a track switch, of two switch-throwing solenoids therefoiya norm'ally op'en circuitrfor the solenoids, a tim ingr relay for closing said circuit, a normally-open circuit, for the timing relay which is closed momentarily by a car rap proaching, the switch thereby to render the timing relay operative, a selective relay in the circuit forthe timings relay and vadapted to determine which 01': the two switch-- throwing solenoids will be operative,,and a stick coil in the circuit of the switchthrowing solenoid for maintaining the selective relay operative so long asisaicl circuit is closed.

In testimonywhereof, I have signed my nameto this specification.

' ROY v. COLLINS;

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