US1377392A - Electrically-operated semaphore-signal - Google Patents

Description

c. s BUSHNELL. ELECTRICALLY OPERATED SEMAPHORE SIGNAL.

APPLICATION FILED SEPT. I. l92u.

Patented May 10,1921.

VENTR BY WTZRNEY ply of current to the hold-clear device, due

UNITED STATES PATENT OFFICE,

CHARLES S. BUSHNELL, or RocHEsTER; NEW. YORK, AsSIGNoR T0 GENERALRAILQ WAY SiGNAL'GOMIPANY, or noonnsrnnfnnw YoRK, A coRroRArioN or NEW YORK.

Application filed September 1, 1920 SerialNo. 407,301, I

new and useful Improvements in Electrically-Operated Semaphore-Signals, of which the following is a specification.

This invention relates to electrically operated semaphore signals usedin railway signal systems.

Semaphore signal operating mechanisms in common use, while differing to a" certain] extent in detailsof construction, generally include some form of a hold ng or retaining mechanism, herein conveniently-termed a hold-clear device, for holdingthe semaphore blade in its oneor more operated positions, corresponding to caution or proceed. Since this hold-clear device is energized the greater part of the time, its efficiency is an important part of the total efiif ciency or economy of the .system, .The hold-clear devices commonlyused, and with which I am familiar, are of the type com; prising a latch or detent operated by an electroma et. It is a well known characteristic of this type'of hold-clear devicethat the energy required to place the device in its operated position, or pick it up, is somewhat greater than that required to retain the device in its operated condition, or hold it up. This characteristic is due to the well known fact that the current in an electromagnet required to attract its armature, is greater than the current needed to hold the armature in its attracted position. In order to make the current through the hold-clear device at different times correspond more nearly to that required, ithasbeen proposed to'provide a hold-clear magnet with a low resistance winding and a high resistance winding, and use the low resistance winding for picking up the device, and the two windings in series for holding the device in its operated position. This change in circuit connections is made by automatic devices, which are preferably so constructed that the change is not made untilthe arma ture of the hold-clear magnet has fully attained its attracted position,.and also without interrupting the current through the windings of said magnet, Inaddition'to these requisites, there sometimes occurs in practice temporary interruptionsinthe Sup- Specification of Letters Patent.

ELECTRICALLY-OPERATED SEMAPHORE-SIGNAL,

Patented. May 10, 1921,

for example, to the vibration of co-ntacts of i if relays or switch boxes by passing trains. Such lnterruptlons of current ma y cause the hold-clear magnet to drop its armature, and

since it cannotpick up until its pickup circuit is establishethit is desirable to make a change-from the holding circuit back to the pickup circuit quickly, and particularly before the semaphore has had opportunity to drop back to any great extent, otherwise there is false.and-objectionablemovement ofphe semaphore to its caution or Stop posi- 1on. a

, In certain applications of semaphore signal operating mechanisms, it is desirable to use "the, hold-clear device to perform the functions ofa relay. For example, the circuit for controlling one operated position of the semaphore, usually the [caution position, may be of considerable length and include a numberof switch box orlever contacts, so

that this circuit cannot be usedto advan-,

tage for an operating circuit of the motor,

1 but must be relayed. It is'the primary pur pose of the present invention to meet the foregoingconditions and requisites and one of the principal objects of my invention is to devise an organization and arrangement of parts and circuits capable of, satisfying these requirements in a simple and eflicie'nt manner, together with other conditions found in the practical operation of railway signalsystems. Other specific objects and advantages of the invention will appear semaphore signal operating mechanismembodying my invention, the parts :of said mechanism being spreadapart andlshown more with aview of making it easy to understand the construction and operation, than with the idea of showing the construction and arrangement preferably employed in practice; and

Fig. 2 is a wiring diagram showing one applicationof my lmproved semaphore signal operating mechanism. 1

Referring t invention applied to a sema hore signal operating mechanismof well own construction, comprising a semaphore shaft 1, to which the semaphore blade G is fastened, t i blade bei g arrang d n the s al way Fig. 1, I have illustrated my I it I The operating motor M' is shown in a sim I 7 so that it tends to move by its own weight" I from the vertical position shown (convenie'ntly termed the 90 position) to a 'llOII- zontal position against a suitable stop (shown diagrammatically at 2), this horizontal position being conveniently termed thefOFpositiOn. 5 The shaft lis connected by-reduction gearing 3 tot motor shaft l.

plified manner, and comprises the usualfield 5 and aniarmature 6. securedto .the shaft 4:.

The hold-clear device comprisesa toothed. wheel 7, which is. preferably connected to theshaftl'by a combinedfriction and ball clutch device, so that said -to othedfwheel may turn freelywithzrespect to the shaft 5i in one direction, butis held against turning, except for the slipping ofthe friction clutchfin the other direction, these directions. of movement corresponding respectively with the movement of the semaphore toward its 90 or operated position, andtofward itshoriz ontal or;0.position; Coeperating withthe toothed wheel 7 is a detent or latchfmechanism, compr sing two plates 8 .pivotallypsutiported at, their upper ends on a suitably fixed member 9 (which inprac tice forms a part offtlie mechanism case).

V 7 A pawl 10 is guided between said plates. by

pins .Qll and is 1 's'pring'pr'essed inward to- Ward the toothed Whieel Tby a springj12. The plates Shave-a pin and slot connection at their-1ower ends to the short arm of an angle lever 13, pivotallysupported on fixed 9 members 14.; To thelongarm of the lever 13 is -conneetedthe armature 15 of the holdcleanmagnetile. This magnetis fastened p to a memberl'? forming part of the mecha- 1 nism casing, and lsprovlded with low resistjance coils or windings L and high reg sistance coils-or windigs stop )in 18'seeured to the lever 13. is arranged to en gage a suitably-fixed member 19, so as to limit-the downwardmovement ofsaid angle anglelever- 13; and insulated therefrom is a bracket 20 which has a pin-and slotconnec;

"to a blocl; 22 of insulatingmaterial'suit ably fastened to a portionofthe mechanism leverr Attached to thelong arm of the tion to the switch member 21.1 This switch memberThas-the general shapeof across,

and is pivotally supported at; its upper end case Contacts 23 and 24-, shown conven- "tionally as varrows, are suitably supported coeperate with the arms ofthe switch member'21.*' The operation of the holdclear. mechanismlis as follows. .*The Iparts-Jare shownin a picked upor operated position,

pawl 1 O being in engagement with one of the teeth .ofthe toothed. wheel so as to pre-' vent rotation of :the motor shaft .4 (in the counterclockwise direction) and-thereby hold the semaphore blade C in itslverticalposi ti'on, At this: time the "'high and low' es re 99 1s t therhblii e i *16 are connectediin series, in a. manner more fully explained hereinafter: When the hold-clear magnet 16 is. 'deenergized," the angle lever 13'and armature 15 drop, due to their-own weight, and this withdraws the pawl 10 from engagement with toothed Ywl1eel7, thereby permitting the semaphore blade tomovetoward its biased position;

At the 'same'tim'e'the switch member 21- is shifted out of engagement with contact'. 24

into engagement with contact 23, for. the

purposes hereinafter explained. When the hold-clear magnet 16 is again energized, its a 'fastenedby screws to a shaft 26, which is connected by segmental gears 27, 28 to the semaphore shaft 1. Associated with the drum '25 area number of contact groups, eachof these groups consisting of a pair ofcontact springs 29, and a contact strip, or strips 30 on the drum 25. The contact springs 29 are carried by bars 31 ofsuitable insulatlng material, which in turn are fastenedfto the framework of the circuit con troller. By

, making; the contact strips on the dr'umof the appropriate lengthand position, the various pairs of contact springs 29'maybe connected electrically in any de sired position of thedrum 25 and throughout any desired range of its movement.

Also associated with the. drum 25 is a de: 3 I 'vlce, conveniently termed a slip contact S.- In

the particular construction illustrated, this slip contact comprises a shoe-like slip mem} ber 32 riding in a "shallow groove around the drum 25; This slip member, 32 is pressed 'against' .the -drumfl 25 by a spring 33,. the connection between .said member and said 7 springlbeing. preferably made pin fit-' ting loosely in sockets therein,.softhatthe member' 32 may travel with the-drum25 to a limited jextent'ineitlier direction] A V v 'contactspring 341s arranged to be engaged by .the slip-'inember32, when'said member is carried in Lone] direction; The friction ;between the slip member 32ai1d the drurn25' V is sufficient tocause movement of said slip member into and out of engagement' with the contact spring-34, The circuit connections controlled by the slip contact Stare between the springs 33%34;

ln order'toexplain the various features of the construction and operation of my 1mproved..semaphore slgnal operating mechanis'm', I haveillustr'ated in Fig. 2 one prac tical application of this mechanism. "Refer-f e s Bis-. 5? isill si ed n a The other circuits are open.

ventional manner two track sections or blocks A and- B, with track relays 35, signals 36 and 3'1 at the entrance to said blocks, andthe parts and circuits associated with the signal 36. Thecontactgroups of the circuit controller are shown according to established convention at 38 and 39, as switch arms moving with the semaphore blade" 36 and making contact withcurved segments through thefangles of movement of said blade indicated. For example, circuit contro1ler-38 makes contact from Oto47. D designates a line relay of the usual construction controlled by a circuit controller 40 operated by the signal 37, said circuit controller being closed so as to energize the relay D, when the semaphore 37 is in the or caution positionfo r the 9O or proce'ed position, or any position in between. K designates a switch box contact, or the contact of a lever,;or'the like. The other parts shown in Fig.2" correspond to those illustrated in Fig. lalready described, the same referencecharactersbeing employed; 1

OperationzThe parts and circuits are shown in Figs. 1 and 2corresponding to the proceed positionof thesemaphorel At this time the'hold-clear magnet 16 is energized with its coils H and L in series, bya circuit which may be tracedas follows: commencing at battery 41, wire 42, contactK, wire 43, front contact 44 of track relay 35, wires 45 and'46, front contact 47 of relay D, wires 48 and49, coilsL, wires 50 and 51, coils H and wires 52'and 53" back to the battery.

When a trainenters the block Aand drops track relay 35, it opens the holdingcircuit of the hold-clear magnet' 16, and allows its armature 15't0drop. This releases the semaphore blade and allows it to gravitate toward its stop position. At the same time the switch member 21 is shifted, thereby establishing a snubbingcircuit through the motor M, said circuit comprising wire 54, switch member 21, contact23,wire 55', snubbing resistance -56,wire 57, andthrough the armature 6 and field 5 offmotor M; The motor M having a low resistance shunt around its armatureand field acts as a generator, thereby retarding the movement of the semaphore blade andassociated gearing, so that it stops in the horizontal position without severe shock and jar. During the movement of the semaphore blade toward its biased position the circnit controller drum 25 is turned in the direction (counterclockwise as shown in Fig. 1) tomove the slip member 32 into engagementwith spring 34, so as to establish an electrical connection between'springs 33 and34. This closesa low resistance shuntforthe coils H of the hold-clear magnet 16 comprising wires 51, 58, slip contact and wires 59 and 52. f

When thetrain leaves the block A and armature 15 of the hold-clear device, thereby shifting the switch member 21 back to theposition shown and establishing an opcrating, circuitforthe motor as follows; COIHIIIGIlCIDg at battery 60, wlre 61, circuit controller 39, (now closed), wire 62, contact 24, switch member 21, wire 54, field 5 and armature 60f the operating motor M and wire 63 back to the battery The'motor drives the. semaphore from its horizontal or 0 position toward its vertical position.' When the armature 15. picks up,the pawl 10 is projected into engagementwith the toothed wheel 7 but on account of the ball a clutch connectionbetween the wheel 7 and the shaft 4, saidshaft may rotatefreely while thewheel :7 is held stationary. After affew deg-recs movement of the semaphore shaft 1, from 2 to;5 degrees, the circuit con troller drum 25 carries with it the slip memoer '32 outof engagement with'the spring 34, thereby interrupting the shunt around the high resistance coils H, and placing these coils in series withrthe coils L. The armature 15 being attracted at this time, the smaller current flowing through the coils H and L in seriesis sufficient to hold up this armature. When the semaphore blade attains about 43, that is, about'2- below its 45 or caution position, the circuit controller 39 opens and interrupts the operating circuitfor the motor M. The semaphore bladeand associatedgearing, however, usually-'moveia littlefarther by virtue of the acquired momentum, so that finallyit is brought. to rest at its 45 orcaution position' and is held there by the pawl 10. co-

ated to the caution. position, closes its cira, I

cuit controller 40, and energizes relay D.-

Current is now supplied to the operating motor M from battery 60 along wires 61 and64, front contact 65 of relay D, wire 66, circuit controller 39 (closed fromabout 40 to 88), wire 62,*contact 24, switch mem-.

. ber 21,'wire';54,'field5 and armature 6 of motor M a d'vf e 6 c o he ba te y- Current is maintained on the hold-clear magnet 16 through wires 46 and 48 and front contact 47' of: relay D; and the signal.

is-operated to its 90 or vertical position 1 and held there.

In addition to the movements already described, occasionally thesemaphore is moved from the;90. position to the 45 position, .as forexample when a train backs into, the

block B from the block ahead. During this movement 'of the semaphore, the hold-clear magnet 16 drops as before, and closes the snubbingicircuit' for the motor. Also -the slip contact S closes; and at about 47 9 the hold-clear magnet 16 picks up again through circuit controller 38. The semaphore blade and its associated gearing, however, acquires considerable momentum during its downward movement and cannot be instantly brought to a stop. Consequently,

'when the pawl 10 is? thrown into engagement with the toothed wheel 7 at about 47".,

the friction clutch. between said wheel and v the shaft 4 slips and the blade drops ,still fartherna few degrees below the 45 posi-' tion. When the semaphore drops below 43 7 the motor operating circuit-is established at circuit controller 39, thereby starting to the low resistance pickup circuit to the high resistance holding circuit of the hold-clear drive the semaphore upward again. During this upward movement the slip contact opens and throws the coils H and L in series.

At about 43 the motor operating circuit'is 7 broken, and after a little more upward movement, thesemaphore settles back and is held in its 45. position by the hold-clear device.

It sometimes happens in practice that a circuit: controlling signal is momentarily interrupted. 'For example, a switch box- *40' contact,as K, maybe poorly adjusted and perhaps the contact surfacesare dirty, so

that the jar and vibration of a passing train opens the circuit temporarily. iThis, of

course, deenergizes the hold clear magnet 16"; but in accordance with the present invention, this magnet may pick up again. as

soon asthe-semaphore blade moves back a few degrees,-since the slip contact is closed by such movement and puts the low: resist ance coil Lalone in the circuit.

It will" be observed that the change-from device is made by the movement of the semaphore circuit controller, andsince' this movement; cannot occur-unt1l after the 7 switch member 21 has shifted, it is assured thatthe armature offthe holdclear device is fully attracted before'this changeis made. In other words, a change from the pickup to the holdup circuit is made by parts set into operation by the attraction of the arma V ture of the hold-clear device but sufliciently slow" acting o assure-that said" arm ture hasattained its fully attracted position, regardless of any delicate or precise adjustment of contacts. Another important feature of the invention is the ability of. the semaphore operating mechanism to pick up at any-part i of its movement, so that temporaryinterruptions of current do lnotsend the semaphore all of the way back to; its 0 position before itcan return to its operated position.

The particular construction and arrange -ment of parts and circuits illustrated may be modified and adapted to suit, varying requirements without departing from the invention. 7

What I claim p by Letters Patent of the United States is '1. In a semaphore signalfloperating mechanism, the combinationf with a hold-clear device having a pickup circuit andaholding circuit, of means operated in accordance withthedirection. of movement of the semaphore -f0r-.controlling said circuits.

2. In a semaphore signal operating mechani'sm, the combination :with a hold-clear device having a pickup circuit and a holding circuit, ofgnieans responsiveto. the dias new and desire to secure rection of'movement'of the semaphore for causing alternat closing ofsaid circuits as the semaphore moves a few degrees in opposite directions- 1 r 3.111 a semaphore signal operating mechanism, ,the combination with a holdrclear device having apickup circuit and a holding:

circuit, of 'slow acting means responding to the energization of said device for changing means operated in accordance with the di rection of movement of the semaphore for out 'interrupting'thefiow of current.

establishing said circuits in succession with Ina semaphore signal operating mechanism, the-combination with a hold-clear device having a pickup circuit 'and a'holding circiut, of-means for changing from the i pickup circuit to the holding circuit as the semaphore moves arfew degrees toward its operated position and for changing from the holding, circuit to .the'pickup circuit as the semaphoremovesbackward a'few d grees from its existing position toward its biased position. v

6.1 In a semaphore signal operating mechanism, the combination with a hold-clear" device having a low: resistance coil and a. high resistance coil, a shunt for the high resistance, coil, and means for opening and;

arness by the hold-clear device for controlling the operating circuit, apickup circuit and a holding circuit for the hold-clear device, and means responsive to the direction of movement of the semaphorefor controlling the "circuits of said device.

8. Ina semaphore signal operating mechanism having a hold-clear device and an operating motor, an operating circuit for the motor, circuit controlling means actuated by the hold-clear device for controlling the operating circuit, a pickup circuit and a holding circuit for the hold-clear device,

and a slip contact responding to the direc tion of movement of the semaphore for al-i v ternately establishing the circuits of said,

device, said slip contact being shifted after a .feW degrees movement of the semaphore.

9. In a semaphore signal operating mechanism having an operating motor and a hold-clear device provided with high resistance and low resistance coils, an operating circuit for the motor, means actuated by the hold-clear device-for controlling the operatingcircuit, a shunt for the high resistance coil, and'a slip contact for opening and closing said shunt, said slip contact being shifted by a few degrees movement of the semaphore in opposite directions. a

In testimony whereof I have aflixed my signature.

CHARLES S. BUSHNELL.

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