US1755772A - Acknowledging device for train-control systems - Google Patents

Description

Q April 22, 1930. c. A. CHRISTOFFERSON 1,755,772

ACKNOWLEDGING DEVICE FOR TRAIN CONTROL SYSTEMS Filed Jan. '30, 1926 Patented Apr. '22, 1930 i I U JER-AL RAILWA ,smile co viren i CHRISTIAN A. cHRIsroFrERsonIor' s'rl Pent, Minn-more, Assreivoaro THE-em,

i AcoRroRArroN or NEW YORK I a oKnow EDenvennvIcnrcR ruliimconrnori sYsrEMs V l Application mammary 30,1926; Serial 'No'. 84,980.

i vinvention i' relates to v automatic train control systems, and more particularly 7 to la device or mechanism, commonly termed an v -the train to a stopatle aclrcaution orstop signal, or "correspondmgcontrol po nt, un-

acknowledging device, which is employed in certain types of train control systems to 'en;

force vigilance on-the part of the engineer.

In the application of certain types of'auto- I I matic train control'systems to railroads,itr

has been proposed to provide means which will automatically apply the brakes and bring less the engineer takes suitable anticipatory action, ordinarily i termed acknowledgement. To carry out {theprinciples'fof acknowledgment itis desirable to include'in the sys'tem.

I v a manually operable acknowledging device,

wvhich the engineermanipulates to avoid the automatic brake application, and which "is wise suitably protected,'so that thee'ngineer I cannot fasten or h'old'thi's 'device in'its efiec ti ve position, "but must acknowledgefeyery unfavorable 's'ig'nal indication. One type of a system embodyingthis aclinowledgin'g'- feature is disclosed in thepatent to WVinthr-op .acknowledging"device. One-'pbjece of; the present invention is t'o provide a simple,-.

eflicient," and "reliable time element mechan1s m,"compr-1s1n'g-]1n one form an electric motor and rejdu'ction gearing," According to the iinvention," 'su'e'li an electric motor and 1: iOtheru-objects, purposes andw characteri'sreductionggearing "as" a time 'element; mechamsm 1S combined with circu ts and" control- -lin gicontacts in s uchaway that theengineer may {acknowledge for a limited I time only,

1 andso thatordinary failures, such as broken wires '1 andiconfnctions'f will be' 1 "on the side of safety;- Inf particularflitis proposed to vprovide an org'anizatiqn in which the time element vmechanism "has to function in order to effect acknowledgement; and failures "of this mechanism ;W i1l': gprevent acknowledg t fe t ires 0f the inventi'oifiwi lb iili'part effective ior a limited time only; or. otherment of the invention, the parts and circuits being.illustrated-more with the view of making it'easy to understand the:natureofthe illustrating the particular construction ,fpret erably employedin practice. 2 a

drawing which shows in aasimplified andd agrammatic manner 1 one specificj embodi-y;

invention, rather than with the purpose; of l Referring to the" drawing, since the acknowled'ging" feature, constituting the sub ject matter 'ofthe present invention,- is ap-, plicable l, to various .type's ofi train '"fcontrol' systems, botha speed control vand 1 a permiszsiv'e stop system, and may beemployed with variousitypes and forms ,ofmeans'fortrans- Y mitting impulses on the trackway to themoving train, either by intermittent "or contin- ;uous control, no attempt has been'm'ade to illustrate any particular type vof f'trainf con jtrol system. :In these-various systems,:how ever,'there existsm some form or other-a suitable means-whichoperates ateach f'cautionor danger sign'akor corresponding-cou- -trol' point, when acknowledgment should'be; j made. "Ordinarily",- thismeaus takes thefornr of a normally closed contact, "automatically openedat the control points; :fand;to: illus trate the adaptability andv application of -;tl 1e invention, a contact 'A isshown, assumed to "opened for a limited: interval of I time, dis tance or: the like, atheach: control point! I Assuming such a controllingcontact A,=or equivalent, the organization inv general, constituting theinvention, comprises a stick mbe controlled by'relay GR, and temporarily opened at each caution or st0p. signal.' It should be understood that this (l0ntaCt::Al.iS

layQSR abrakencontrol device,.assumed to'be 1 c an electro-pneumatie valvev EPV; a reset switch. RS an acknowledging;contactor or push button AC and a time element mechanism-, 'including an electric motor'M, a speedresponsive device oricentrifu ge C and asso ciated contacts and circuits. I. All of these parts are carried on'the railway vehiclea'or train. The relay SR is of any suitable, type, such We l 1mm :eqmmqnly used -ea or having otherauxiliary features inaccordance wit1 1 the established practice of the art.

locomotives or other railwayvehicles. The

electro-pneumatic valve EPV isassumed to 7 act upon suitable brake applying means to give the desired automatic application of r the brakes, either by venting the brake pipe direct, antomatic ally. operatingthe engineers brake' -valve, or the'like, producing a limited reduction in brake-pipe pressure, if desired,

The reset switch BS is of any suitable construction for opjeningabreak in .a normally closed circuit, and closing a break in anormally open circuit. I As shown, this reset switch RS comprises a simple spring return plunger, having; a contact member 3 movable. from engagement wltha palr of stationary contacts, ind cated conventionally as arrows,

into engagement with another pair of contacts. This resetswitch is ordinarily located so-thatit is accessible only from the ground,

'7 and cannot be -operated until the ti' ain has been brought :to a stop. The acknowledging contactor AG, asshowmcomprises asiinple pushbutton or strap key 23, having normaflly closed, and normally open contacts. v

The time element mechanism comprises a small electric motor, ordinarily .dji'rect' current, whi'ch has constant speed characterist cs. This motorlsshown diagrammatically as a shunt-wound motor; The motor "M drives the shaft l, which is connected by i Y beveled gears 5 and 6 tea shaft? of the speed- 7 responsive device or, centrifuge centrlfuge C 1s lntended tQ-HlOVQQ'COIltElCt disc 8 into engagement with-stationary contacts 9 while the shaft l' is rotating, and to open these contacts as soon as" this shaft stops... "This centrifuge G may take various forms;

and in -its simplified construction shown coinprises a lower collar, fixed was shaft '7, an upper'collarslidable on said 'shaft'in' opposition to a spring, and springarms con-.

'necting said "collars and provided with weights. The shaft l'is connected by a don ble iworm reduction gearing, comprising the worm'10, worm gear 11, shaft :12, worm 1'8, and 'worm' gear 14, to a circuit controller-shaft 15. "This reduction gearing is designed, in conformity with the normal rnnningspeed of the motor 'M,'so as to cause the shaft 15 to. make one complete revolution, during the time interval selected for acknowledgment, such as, for'examiple, fifteen or twenty seconds The shaft 15' opens and closes three pairs of contacts at different positionsoftheshaft, and for different tions'of its revolution. Various constructions may be employed to perform this circuit'controlling function." In 'the form shown, a

' drum,- of suitable insulating material, is se- Ycuredto the shaft '15,and has fastened there- .Lon contact strips 1.61and 17 and a cam 18.

sliaft715 and its'drumare shown in the a 5 normal initial. position. The Contact strip 16 engages and bridges contact fingers 19, after the drum has been moved a short dis tance from its initial position counter-clockwise, as indicated by the arrow, and maintains this contact until the drum has nearly completed one revolution. ,Gontact strip '17 bridges the fingers QOlinTthe initial position of the drum, and for a short distance of moveinent-thereof away from the lnitlal posit on.

The ca'm 18 engages a roller 21 in the initial position of the drum and Zholds the spring finger or contact member 22 out of engagement with its cooperating contact for a small distance of movement of the drum from its initial position." The sequence of opening and closing of these contacts will appear from the following explanation of the operation.

' 0pemtion.ll henthe train passes :a cant1on,or astop s1gnal,or a corresponding control point, at which it is ClBSlI'QCl' toenforce aclmowledgement, the contact A is opened,

breaking a normally closed stick circuit for the relay SR. As a convenience in illustrationythis-circuit, and also theother circuits shown, are indicated conveniently as terminating at B and G,indicatingoppositeterminals of the battery, turbo-generator, or other suitable source of current. 1

The normally-closed. energizing circuit for r the relay SR may be traced as f-ollows-:

commencingat1B, wire 25,0011tflClLAyWlI8 2.6,

frontcontact liof relay SR, wires27 and :28, relay SR, and wires-29 :and 301 0 G.

Electroepneumatic valve EPV is normally energized by acircuit which may hex-traced asfollows commencing at B, wires 81 and 32, contactmember .3 of the reset switch RS and its normally closed contacts, wire 83,

.valve EPV, wire84c, frontcontact 2 of relay SR, and wires 35 and "30 to 1G. Assuming first that the engineer does not properly acknowledge, when the contacts A open and break the normal energizing circuit for the relay SR, this relay is de-energized,

opening its front contact 2, and de -energizing contact member 3 of switch RS and its normally openeontactswires 37 and 28fre-lay SR, and wires 29 and 30 to C. -It will be evident tha-twhen this pick-up circuit is established,'the energizing circuit 'forthe valve EPV hereinbefore traced, is at'the same time broken at'the normally closed contacts of the switch RS."Th-us, while the relay SR is reenergized, the :valve EPV-cannot be-energized, and the brakes released, lllllilllthB reset switch BS is restored to its normal position.

Consequently, the reset switch cannot be carelessly-or: improperlyleft in the resetting position, but mnstlbe restoredto normalieach time, in order to :permi't'the train-to proceed.

,Inor'der to prevent this automatic brake appl ca ion; and stopping of the train, -;the engn'icer 1S required to operate his acknowl ed ng contactor AC: .prior to the opening of the contact-A and de-energi'zation.oftherer lay SR In other :words, the'engineer must forestall the automatic brake application,

acting upon information obtained from the,

wayside" signals, or; suitable cab indicating means,'1fso provided. When the engineer operates the acknowledging ,contactor 'AG,

closing its normally opencontacts',- the motor in isenergizedandstarted by'aci'rcuit as follows commencing at B, Wired0, switch' 23 down,"wi rej4l,feontacts 1 7'.20, Wires l2 and '43, motofrM, and wire 44 to G; Shortly after the motor starts, andthe shaft has been turned icounter-clockwise thron'gh Era small angle, the contacts 16 1'9-close, lighting an I indicator lamp 1 through a circuit from B,

1 wires and46, contacts 16 19, iwire' 47, "lampI andwirei48to (l-H'Be'fore these con- "tacts close, l1owever, the;cam.18 rides out 1 from under the'roller'21, a1lowing the spring finger 22 to engage its contact; and when the lamp I lights, the engineeris supposed toreturn the acknowledging'contactor AG tothe normal pd'sition, establishingf'a secondenergizing circuit for the motor M as follows starting atB', wire lO, switch 23 np, fwire 49,

finger 22 down, wires andl l3, motor M,

andwire 44 to Cg; After ashortit'ime, sufi.

'cient to afford theengineernall reasonable latitude in restoring. his acknowledging contact-or AG to norinal,i the' "coi1tact's 17-l-20 open, breaking the first energizingcircuit for the motorM although the circuit may already have been broken at, 23- 11 by the engineer. If the engineer has'properly returned'his acv knowledgingco'ntactor to I the normal position, a supply of current to the motor is main- 7 tamed through the finger'22, and the motor continues" to drive the shaft-15 until,'near the end ofjone revolution, the cam 18- 'engagesthe roller 2 1-an d opens contact at the finger 22.- The friction "of the parts-driven by the motor 'briri gsit quickly to rest ,and the parts'are so proportioned and designed that, once the finger 22 is ppenedfby thecam '18,the motor -cannot overr u to the point where this finger again'closed',bnt will stopand remain at rest until the acknowledging contactor isat ain o er ted; r VVhileand'solong as the shaft is'bein rotated bYj he motor M,-the centrifuge maintains the' contacts closed, establishing 'an'au-Xfliary energizing -'circuit forkth'e .re1ay- SR,Zincludinga shuntfor the contact edging contactor in the operated position, with any effect because the shaft 15-will only *be rotated a short distanceuntil the contacts 17-20 open, whereupon the motor stops, and

'the co'ntacts 8-9 open, eliminating the preventing or suppression of automz-itic'braking. vl-l'ence,if the engineer holds or fastens down his acknowledging contactor, the brakes will be automatically applied at the next steps "ping control point. If the motor shonld be- A, which may betraced as follows from B, wires 45 and '57, contacts 8-9, wires 52 citation of the" timing mechanism, constitutand 26, front contact 1 of relay SR, wires 27 vand'i28, relay SR, and wires 29 and 30 to C.

Thus, duringthe time interval or cycle or op- 7 inc; onerevolution :of the shaft'15, the relay SR is maintainedenergized, and the autoinaticbrake application prevented, in, spite ofthe Openingofthe contact A. I Obviously,v the engineer must operate his acknowledglng contactor and get the shaft 4: in motion to close the contacts 8 and. 9 before the contact A'opens'and the relay SR- is dc-energized; or, ln 'other words, the engineer must forestall the automatic brake application, If thecontact A'is operatedfquickly upon the reception a control influence from the-track'- way, without any precedlng intervening delay, the engineerniust observe the indica tions' of the wayside signals and operatehis acknowledging con-tactor AC before passing the control point'for the caution or stop signal; and if he fails to do'so, the relay SRis- 'de-energized, the brakes applied}, and 'the train brought to a stop.

gPointing ont some of the "characteristic 7 features of the invention, iltshould be noted v that the engineer cannot hold his acknowlcolne' damaged, or its operating -circuits broken, or other failure occur preventing the timing operation, the centrifuge C fails to rotateQand the contacts 8 9 remain open, so that the brakes are applied at the ffirst stop ping control point. If the timing mechanism 1 stops at an intermediate point in its cycle termine accurately when he should restore hisacknowledging'contactor AG to. normal. In other words, when the lanipl lights, the

engineer knows "that the motor energizing circuit is closed atthe contactfin'ger 22,"ai1'd r v I that he should restore his'acknowledging contactor Ae'promptly, before th'e'motor circuit started, so

" broken at tl'ie contacts I'l These contact'sglY- QG are preferably made to remain {preferably a made relativelyshort.

' I It will be obs 1 tinrehe -;.E1mit'e'd time control point; In practice,tli1s time interval rved that the engineer may "rate his tn'owledging contactor any shes, and may hold it down as long as he pleases, without producing any automatic br'alre application; but if he holds it down,- the brakes are applied at the first 'stoppii-rg control point, and if he operates the acknowledging. contactor too soon before passin-g the control point, the time element i-n'e'chanism completes its cycle and stops.

Consequently-the engineer in any event must form the a'cln i'owledging act Within a efore passing each stopping isselect-ed to afford reasonable latitude ing the ratio of the reduction gearing between the shaft and shaft 15, or by varying the lspeed'of the motor M, by varying its "oltagc, crby any other well known ex pedient, V Only one specificembodiment of the presand. it should be understood that this is to illustrate the nature and purpose of the in vention, rather than its scope and that various changes and modifications may be made in the construction and arrangement of ciras is shown and described, and in adapting the invention to various types of train control systems, all without departing from the invention or the idea of means underlying the same. l

lVhat I claim is I 1 1. In an automatic'traln control system, the combination with a brake applying appliance, a stick relay governing said appliance, means controlled from the trackway for temporarily interrupting the stick circontrolling. means for energizing the electric Ifi tQT for elimited number of; revolutions for r of when closed, and manually controllable time element mechanism for closing said contacts for a limited timesai'd mechanism'comprlslng, an electric motor, a centrifuge for closing said contacts only while said motor is operating, an acknowledging contactor having normally closed and normally open contacts,circuit controlling. means driven by the motor, an'energizing' circuit for the motor irrclu'dingi the normally. open contacts of the acknowledging contactor and normally closed contacts of said circuit controlling means, and an auxiliary energizing circuit for-said motor including the normally closed contacts of the acknowledging contactor and normally open cont-acts of said circuit controlling means, said normally open contacts of. the circuit controlling means being autois mati'cally closed after the motor has made a I few revolutions and being maintained closed until th'ejmotoi'has completed a number of revolutions consuming the desired time interval, said normally closed contacts of the circuit controlling means being automatically opened a short interval of time after said normally open contacts of the circuit controlling means have been closed;

ent nvention has been shown and described,

4-. acknowledging device of the character described comprising, a power-operated time element mechanism, manually operable means 'shiftable to one position forinitiati'ng operation of'said mechanism but ineffective in that positionto maintain such operation for morethan a short interval of time, said manually operablemeans' when shifted to anotherjposition after such initiation of o'peratioir of said mechanism acting'to maintain that operation fora limited time, and brake preventing means effective only while said mechanism is operating.

5. Ina train control system, acknowledging meanscomprising an electric power-operated time element device having a cycle of operation consuming predetermined time interval, manually controllable means effective if actuated alternately during said cycle -of operation to two different posit-iol'l's to cause said mechanism to com-plete'its cycle ofoperation, and means efi'ectiv'e' only While said mechanism isfoperating to preventan autom-atic'b'rake application. V

An acknowledging device f-or train controlsystems for closing contacts for a predetermined period of time only for each acknowledging act comprising, a shaft, a

centrifuge driven by said shaft, contacts closed if said centrifuge" is rotated above a predeterminedspeed, a motor for rotating said shaft; afsta-rti-rr'g, circuit for starting said motor including; no ii-ally epenmanually' opthereof. 7 a 7. An acknowledging device for train conerable contacts, and a stick circuit for said motor including normally open contacts closed during a predetermined extent ofrotation of said shaft, whereby said motor if once initiated will remain in operation during a predetermined extent of rotation trol systems for closing contacts for a predetermined period of time only for each acknowledging act comprising, a shaft, a centrifuge driven b said shaft, contacts closed if said centri uge is rotated above a predetermined speed, a motor for rotating said shaft, a starting circuit for starting said gize d under favorable traific conditions ahead;an energizing circuit for saidbrake control means including a front contact of said control relay; and means requiring recurrent manual action for keeping an auxiliary circuit for said brake control device motor including normally open manually op- I erablecontacts, and a stick circuit for said motor including normally open contacts closed'during a predetermined extent of rotationof said shaft and contacts closed only if said manually operable contacts are in their normal open condition, whereby said motor if once initiated will remain in operation for a predetermined cycle of operation provided said manually operable contacts are returned to normal.

8. An acknowledging device for closing an auxiliary circuit for a brake control device to maintain such brake control device energized while the main circuit for said brake control device is open comprising; a shaft; a motor for driving said shaft; a contact in such auxiliary circuit closed only while said speed; two contacts closed alternately during V the operation of said motor, one-0f which is closed during a predetermined number of revolutions of said motor and the other of which is closed at all'other times; a push button for controlling a normally closed contact and a normally open contact; and a circuit for said motor including two branch circuits in multiple onebranch of which includes said one contact and said normally closed contact, and the other branch of which includes said other contact and said normally open contact.

9. Car-carried apparatus for train control systems comprising; normally energized brake control means; a control relay energized under favorable traflic conditions ahead; an energizing circuit for said brake control means including a frontcontact of said control'relay; and means requiring recurrent manual action for keeping an auxiliary circuit for said vbrake-control device closedincluding; a motor, a contact closed only when said motor is rotating above a predetermined speed, and manually operable means requiring intermittent operation to maintain said motor operating so long as said control relay is de-e'nergized'.

shaft is rotating above a predetermined 10. Gar-carried apparatus for train con trol systems comprising; normallyenergized brake control means; a control relay ener-

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