US2451976A

US2451976A - Control system

Info

Publication number: US2451976A
Application number: US631395A
Authority: US
Inventors: Maurice E Reagan; Willard A Derr
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1945-11-28
Filing date: 1945-11-28
Publication date: 1948-10-19
Anticipated expiration: 1965-10-19

Description

Oct. 19, 1948. M. E. REAGAN ETAL 2,451,976

CONTROL, SYSTEM Filed Nov. 28', 1945 WITNESSES: INVENTORS r Maurice 7 Faye/1 and MY/ard 0.0;: m

Patented Oct. 19, 1948 CONTROL SYSTEM Maurice E. Reagan, Pittsburgh, and Willard A.

Dcrr, Wilkinsburg, Pa., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 28, 1945, Serial No. 631,395

9- Claims. 1

Our invention relates, generally, to control systems and it has reference, in particular, to automatic control systems for starting internal combustion engines.

Generally stated, it is an object of our invention to provide an automatic starting system for an internal combustion engine which is simple and inexpensive to manufacture and which iseasy to operate.

More specifically, it is an object of our invention to provide for cranking the engine of an auxiliary generator periodically at timed intervals until it starts, when a supply of electrical energy from a normal source fails.

Another object of our invention is to provide for predetermined on and ofi periods for a starting motor of an engine until the engine starts, or until a predetermined number of attempts have been made to start the engine.

It is also an object of our invention to provide for determining the number of attempts to start an internal combustion engine by means of a chain of counting relays.

Yet another object of our invention is to provide an automatic cranking system wherein a starting sequence is continued for a predetermined number of times if the engine fails to start, or if it fails to run for more than a predetermined time when it does start.

A further object of the invention is to provide for connecting the starting motor of an internal combustion engine to a source of electrical energy for a starting operation, and to disconnect it therefrom as soon as the load is removed from the motor, indicating that-the engine has started.

Other objects will, in part, be obvious and will, in part, be explained hereinafter.

In accordance with one embodiment of our invention, switch means energized from a normal source of electrical energy may be used to normally connect a load circuit to the normal source. when the normal source fails the switch means returns to the deenergized position and connects the load circuit to an auxiliary generator. The starting motor of an internal combustion engine driving an auxiliary generator is thereupon connected to a source of electrical energy for a predetermined time, or until the engine starts. If the engine fails to start the motor is disconnected from the source for a predetermined time, and this sequence is repeated a predetermined number of times under the control of a chain of counting relays. Should the engine start during a starting period, a series relay in the starting motor circuit operates to stop the starting sequence.

The counting chain is reset by a time delay relay which operates only a predetermined time after voltage is applied to the load circuit from the auxiliary generator. Whenever voltage is restored to the normal source, the load circuit is reconnected thereto and the internal combustion engine is shut down.

For a more complete understanding of the nature and scope of our invention, reference may be made to the following detailed description, which may be studied in connection with the accompanying drawing, in which the single figure is a diagrammatic view of a control system embodying the invention in one of its forms.

Referring to the drawing, the reference numeral l may denote, generally, a control system for a power circuit wherein a load circuit including a load ii may be normally connected by switch means I2 to a source l3 of electrical energy through the conductors M. The switch means may be provided with an operating windin I5 which is energized from the normal source i3, so that upon failure of the normal source the switch means returns to the deenergized position and connects the load to an auxiliary generator I! which is provided with an internal combustion driving engine l8 having a starting motor 20.

A starting switch 2| having an operating winding 22 may be provided for connecting the starting motor to a source of electrical energy such as the battery 23 in response to operation of a starting control relay 25 which has an operating winding 26.

In order to provide for predetermined on and off periods of the startin motor 20, on timing means comprising, for example,

pendulum type relays

21 and 28 may be provided in conjunction with

timing relays

29 and 30, respectively, which are preferably of the slow release type, The relay 2'! controls the operation of the relay 29 through the actuation of armature 32, which may be of the pendulum type and adapted to make intermittent contact for maintaining the relay 29 in the energized position for a predetermined interval of time after the pendulum type relay is deenergized. The pendulum relay 28 is controlled by the timing relay 29, and in turn controls the timing relay 30. The off time periods may be controlled by a pendulum type relay having an armature 36 for maintaining a slow release relay 3! in the energized position for a predetermined time after deenergization of the relay 35.

For the purposes of providing a predetermined number of on and off periods in sequence,

counting means 40 may be provided comprising, for example, a plurality of counting relays ll through 43 which may be connected so as to be sequentially operable in conjunction with a plurality of

sequence relays

48, 49 and 50. A master relay 52 may be provided for controlling the operation of the counting and sequence relays under the'control of the starting control'relay 25 and a load responsive relay 54 which may be operable in response to a predetermined value *10 of current through its operating winding 55: in the operating circuit of the starting motor 20.

A starting relay 56 may be provided for open-"=- ating in response to deenergization of theload responsive relay 54 during a starting interval-for affecting deenergization of the starting control relay 25. A voltage responsive relay- 58fmay-'be-%1 connected in the output circuit of the auxiliary generator IT to provide a holding circuit for the starting relay 5% as soon as the voltage of the 20 generator-IT reaches a predetermined:value A. field relay 59 may be provided for affecting.:ener gization of the field-winding 66 of-the -auxilia'r generator as soon-asthe engine 18-reachesapre determined speeds Means-such as thez throttle gg, control -device BZ -may =be provided= for' openingi-r the throttle of the engine Whenever the loadvis transferred to' the generator l 7, and for shutting down the engine I 8 whenever the" switch: means l2 returns to the energized position in response: to a predetermined volta e'from the normal source" of supply 13.

In'orderto provide for controlling thestarting' sequence so as to takecare of momentary starts of the engine which do-notslast fora predetermined time; means such'as' thestime delay release relay a 64 may beprovideda The relay M may"be of'any1 type-Well known in the'art, 'and'mawfo'r example; I comprise an I operating Winding 6 5 energizedin response to energizatioirof the load! i and"-.ar-' ranged for actuating an armature 66" -which' may be provided with a clutch lever '6'!"for;actuatinga movable clutch member- 68 which is disposed to engage a clutch member'fiil'; Theclut'ch' membe 69 may be driven by means of a motorlfi foractu ating cam members '82 and-73' -againstthe 'pres sure of-a spring 'H for actuating latch members 15 and 16." These latchmembers interfererwith the movable contact arms '-l'l-"and -l8 -'ofthe -relay; which in the releasedxposition engage stationarycontact memberslla and'l8a;lrespectively; 'When theoperatingzwindingi 65 is deenergized; the clutch members 68 and 59 separate, so that the-cams 32 and V3 areactuated byc-therspring'ji 4*, to release: thelatcheszil 5 andilfi zalmostn.immediately;Where r by theicontact armsx'lt'i and 18 whi'cnarare actuatedv i" by thETSDIlllgiTQlwtO makepcontacttwith th'e sta tionarycontactmembersrl'ia and-rltmia're locked.,.sf, in the'contact making positio'nav.

when'svoltageris reappliedrto 'the1;loaci-::circuit 60 and: the operating winding GEii reenergiZed; lithe" clutch-:members 68:; and :59: are immediately. reengaged but a-substantial timezdela'y'lofiapproxa imately i'three minutesa-occurs": before rthe: latch membersrrlizandflfi aretsactuatedby the'xcamso'i and 4 l3'in response .to' operationoofithemiotor "i8, to permit: separationiiof the contact arms fl? and 13 from "their stationary-"contact members-lid and'aiszzi' Accordingly, even though? the engine: l7 should-start momentarily, "unless it runs for; theL-fullainterval'" of three minutes the counting SyStGmTLQQ 'JIWi'H' HOll 'bB reset "and theostarting; sequence will continue tothe end of the sequencer Should ithe engine-mun 1 for an interval or *longei than three'minutes, the time delay release reI-ay'" 64 will reset the counting system 46 and a new starting sequence will be commenced.

Under normal operating conditions, the opcrating winding 15 is energized from the source [3, and the switch means i2 is in the operated position as shown, thus connecting the load H to :the source: [3; througn'contact members [2a, IZb'and l2c'. Upon the failure of voltageof the source i3, or the reduction thereof below a predetermined value, the switch means I2 returns to thea-deenergized position, disconnecting the load II from the source I3, and connecting it to the auxiliary-generator I! through contact members l2a;-12biand;.l2cand their respective back contactsr' The" throttle control device 62 is energized theoperating Winding 65 of the time delay release relay 64 is deenergized, and the relay opcrates contact arms -11; lfi into engagementiwith stationary contact members :l-Ia; 1821; respectively-. 1 An energizing circuit is thereupon :prepared for I the pendulum relay 21 from negative: througl'iithe;= aoperating winding of w the relay 21, through back contactand armature52d Otthemaster: relayefii fl conductor 89} contactmembers- 11w} :conta ct tar-m 11, and a cutout-switch 8'l to positive: Relay 2'! operates and provides an energizingxw oircuitfor the slow'release relayzgfrcmnegative through the operating windingof "the rela y -29; front contact and armature 32-, conductrjrs SZt 83 and-8ilg stationary contact members 'i'iafcon tact arm '11, and the cutout switch Sl to positiver Operation of the; relay "29 provides an obvious energizing circuit fork-the" pendulum" relay 2%! thrQugh'arm'ature'ZBa and front contact-ofthe slow release relay, 29. ".The pendulum relay'. 28"" thereupon provides an obviousenergizing circuitj" Torthe slow release relay 3!! through armature 33 and front contact.

Operation of the relay 3U.j'.pr,ovide's.an 'enerw. 1 gizing.,circuit,..for ,the. .start a control .relay 25f exl-i tendingafrom negativethrough foperating wind-i "ing..26-, ..back .,contact and armature .fifibnof, .the.

counting; ,relay 4 6, conductor, 7 84a conductor 8 5,. back contact and armaturet'lanf thevsloworee lease relay 31, conductor Bar-armature g3ila' andl f front: contact-of thecslow release -relay.;3 1 s ductonEL-back contact andaarmaturefifia fe-thes-x start relay 56,-cond-uctors 89; 83: and, ,8 0,.--:contact l i member-11a, .contact,arm,- 1 1- and.v cutout "SWitCh.-1 81 to positive; r g

5, 'I'he start- :controlwrelayn 25- --operates; closing. armature 2 5a and: front-i contacts-:to provide. rant energizing circuit for 'thei-operatingwinding-:22 of the starting switch 2 [which connects theusztarts ing. motor. 20 to-thebatterys-ZS;Armature 25c-andvzr -;.front: contacts provide: ,a holding circuitrin; shunt:

with-armature:31a=and,itsiaack contact:

As'scon-asthestarting motor Zflr-issenergize the;loadsresponsiverelay 54'?operates'ganduprovidesan venergizingtcircuitfiior"the: master \relas zfi ZQGX;

tending .from "negative 'through' the'-- operating Winding 'of the relayi 52 through conductor :9 front contacts: and 1 armature 251),: front contacts :5 and armature'fi l'a R of the :load responsivecrelam i through 'cond-uctors-89;"83 and'80;stationarycon-"u tact Ha, contact arm T! and cutout switch 8 I to positive." 7

The master relay fi2f'operatespproviding a holding circuit with the load-*responsive relay 545 through' armature =52band 'front contact; and; at

"the same timede'energizing-zthe operatin zrwinding of the pendulum relay 2! by separating armature 52d from its back contact.

The armature 32 of the pendulum rela 2! thereupon vibrates for a predetermined interval of'time, during which the slow release relay 29 is periodically energized and deenergized so as to be maintained in the energized position. At the end of this time, the relay 29 releases armature 29a and interrupts the energizing circuit of the pendulum relay 28, which likewise retains the slow release relay 30 in the energized position for a predetermined time interval.

When the master relay operates, armature 52c engages its front contact to provide an energizing circuit for the first counting relay 4|, extending from negative to the operating winding of the relay 4| through conductor 95, back contact and armature 486:, back contact and armature 49a, back contacts and armature 50a, and front contacts and armature 52c to positive. The counting rela 4| operates and prepares an energizing circuit for the sequence relay 48 through armature 46a, and front contact. Operation of the sequence relay 48 is prevented by reason of a shunt maintained by the master relay through front contact and armature 520.

At the end of the time interval determined by the'relays 21', 28, 29 and '30, the start control,

relay 25 is deenergized by the opening of armature 30a from its front contact. Accordingly, the starting switch 2| returns to the deenergized position, and the load responsive relay 54 is deenergized. The master relay 52 is deenergized by the opening of armature 25b from its front contacts, and the shunt is thereupon removed from the sequence relay 48 so that it operates. At the same time, the off timing period is initiated by the'opening of armature 52c and front contacts of the master relay, which deenergizes the pendulum relay 35, and the on timing relays 27, 28, 29 and 30 are again energized.

At the end of a predetermined interval of time the slow release relay 3'! releases and prepares the start control relay 25 for reenergization since the slow release relay 30 is already energized. Accordingly, the start control relay 25 completes an energizing circuit for the starting switch 2|, and th starting motor 20 is again energized in an attempt to start the engine l8. As soon as the motor 20 is connected to the batter 23, the load responsive relay 54 picks up, and an energizing circuit is again prepared for the master relay 52. Operation of this relay again starts the on timing period by sequentially affecting deenergization of the

relays

2T, 29, 28 and 30. At the same time the off timing relays 35 and 3'! are energized to prepare for a subsequent on timing interval.

When the master relay 52 operates for the second'time, the second counting relay 42 is energized through a circuit extending from negative through front contact and armature 4| b, of the first counting relay, front contacts and armature 48a of the sequence relay 48, back contacts and armature 49a of the sequence relay 49, back con tact and armature 50b of the sequence relay 5D, and front contacts and armature 520 of the master relay.

When the master relay is subsequently deenei gized upon the return of the slow release relay 3'! to the deenergized position, the sequence relay 4.! is energized in series circuit relation with the counting rela 45 upon the removal of the shunt through front contact and armature 52c of the master relay. If this sequence continues, the

counting relay 4| and the sequence relay 48 are deenergized upon operation of the sequence relay 49 by the opening of armature 49b and its back contact. The counting relays 43, 44, and 46 are sequentially operated in conjunction with the sequence relays 50, 48, 49 and 58, respectively, upon subsequent operations of the master relay. If the engine I8 is started during any of the six starting attempts counted by the relays 4| through 46, the system is locked out,

Should the engine l8 start during any one of the starting sequences, Voltage will be applied to the field Winding of the generator I! by the field rela 59 whenever the engine l8 attains a predetermined operating speed. Accordingly, the voltage relay 58 will operate in response to the voltage of the generator.

Since the load responsive relay 54 returns to the deenergized position when the load is removed from the starting motor 20 by the engine |8 starting, an energizing circuit is prepared for the start relay 56, extending from negative through the operating winding of the start relay through conductor 96, conductor 91, front contact and armature 52a of the master relay 52 and back contact and contact member 540. of the load responsive relay 54, through

conductors

89, 83 and 85, contact 11a, contact arm 11, and cutout switch 8| to positive.

The start rela 55 operates, and interrupts the energizing circuit for the start control relay 25 by'opening armature 56a from its back contact. A holding circuit is provided for the start relay 56 through armature 56a and its front contact. The starting switch 2| is thereby deenergized, disconnecting the starting motor 20 from the battery.

As soon as the voltage is applied to the load H from the generator I1, the operating Winding of the time dela release rela $4 is energized, and the motor 76 begins to operate to actuate the latch members 15 and i8. Due to the gear reduction between the motor 1!! and the cams l2 and 13, a relatively long interval of time on the order of three minutes is required for this operation. Accordingly, the counting means 40 will not be reset until the end of such time interval.

Should the motor l3 start, but continue to run for less than three minutes, the counting chain will not be reset and the starting sequence will be continued from wherever it left off, proceeding to the end of the sequence of six operations, in case the engine does not start. However, should the engine |8 start and run for more than three minutes, the time delay release relay 64 will have operated to open contact arm '1'! and contact member Fla. The counting means 45] are thereby deenergizecLa-nd should the engine l8 thereafter stop, a completely new sequence of starting operations will be initiated.

Should the voltage of the source l3 return to normal, the switch l2 operates to disconnect the load I from the auxiliary generator I! and connect it to the source i3. At the same time, the throttle control device 62 is deenergized by the opening of armature |2d from its back contacts so that the engine I8 is shut down.

From the above description and the accompany'ing drawing, it will be apparent that we have provided an automatic starting system which is both simple and effective. A plurality of tensecond attempts to start the emergency engine driven generator are provided in the event of loss of the normal source of power with a five-second off interval between each period of cranking.

Lockout of the equipmentv is affected after six successiulzattempts *tostart thenengineq: Accordac.

inglmmthe'. manimumrprotection-ris provided for? both the; starting'11equipment"and the.rcontinuityv ofqservice is maintained; 1at1z'a "relatively! high;

standardrout departing from the. spirit or scope thereoffllt'is' intended thatvall" the-*ma-tterwontained in rthe above": description: and shown: in the. accompany;-

ingnidrawing lshallabe' considered as: illustrativer:

and-notrin a limiting sense;

Waclaimras; our. invention :7 :1

1. {In a rcontror'system'iorcan internal.- combus-z tion engine having a starting motor-,switch means operable: to .connect themotor: to a source-oi elec-r trica-l'zenergy, timing :means operable to 'efiect'ope eration" of ftheZSV/itCh means-for a predeterminedw time; additional timing means-operable to render? the switchr'means inoperative foria predetermined).

time-,ncontrol means :operable: to provide 'for-'-op=f eration .Of'. -the rsw-itchi means: a apredetermined number-sci times 'and means responsive to-thearmaturecurrent of .the i engine starting zmotoroperable-etc riprevent further operation 10f the switch means: z

2. For use in starting an ti-nternaL-combustionm engine..-harvinga a starting ;motor, a first timing means -switch means operabIe- -underthe control of said-first=-timing means'to connect-the motor to a source of electricalenergvfor -a predeter= mined.-time;.-a seeonditiming means' operable-t0 prevent operation" of ,theyswitch means fora predetermined-.-time,- control; means responsive to the connection of the motor to said source, and count-' ing means: comprising a chain. of relays sequentially :operable-v in response; to operation :ofthe a control means toe provide -for "a predetermined maximum number of operations of the-switch meansinsequence.

3.;FO1L'L1S6 in a control systemlfor an internalcombu'stioneneine.havinga starting '-motor and arranged to drive anflemergency generator for supplyin electrical .e'nergy to a loadcircuita con- 1 trol system comprising, control means operable in,

response to a predetermined electrical.condition of theiload vcircuit, timing means .operable,.to ef-..

fectconnection of the starting, motor. to a source 7 of "electrical'energy for a predetermined time. s

additionaltiming means operable to prevent reconnection'of thegmotoritothe' source for a predeterminedtime; relay means operable, in ,re-. sponsegto connection of the motor to the source to efiec't'alternatepperation of the timing means, a and'a chain of s'equentiallyoperable vrelays operableunder the control of the relay means to limit themumber of valternate operations of the timv ing means:

4. A controlv system for the starting motor, of.

an "internal 'combu'stionengine.comprisingtiming means operable toefi-e'ct connection of the motorv to a .source of electrical energy ior. a predeterr, mined time, additional timing means preventing connection'of'themotorto, the source; during a predetermined time, control means responsive. to

sponsive-toa predetermined reductioninmthe load on the starting motor for preventing vfurthenconv, nections'of the startingmotor .to the source.

5. For 'ausesin i controlling.zthegsstartingzzmotorm of an internal combustioni' enginevconnected?stoi. drive an auxiliaryrgenerator:dis'posed: toibe cone nected by switch, means: to a=loadciri uitrimr gsponse to predetermined= conditions" of energization of the load; circuit, a control *isystemrcome prising; means, responsive to predeternfined" co ditions: 1:0fii energizationz: of :the; load; circuit; to connect the auxiliary-generator: totthe: load; cir: cuit: Zto-rimprovesaid i conditions, timingr means operable in'response to said meansyzswitc'hmeans operable to connect the'startingmotontoa source a of: electricalaxenergy -=Ior a ,predetermined time in-response' to? operation :of the timing meansitz additional timings means operable to prevent;

operationnof' the? switch means :forca predetere mineditime; counting vmeansroperaloleto rlimitthe number of operations: of the switch :meansxzin *a sequence; control imeansi'responsiveittoienergiz ,tion of the starting motor controlling the oper tions'cf :theatiming means and-counting: means; means: responsive "to a reduction of z the 'vloadzon the-starting motoriduring a starting cycleroper bl'eto'prevent; furtherureclosures :of therswitchr-r.

ameans; and:circuit:means controlled by the: means responsive to saidcp'redetermined condition vof'w energization operable to render.theicontrolfsys tem'iineffective when th'evloadi condition iS im II- proved-1':

6. 111a power-system; an auxiliary"generatordrivenbyanrinternal combustion engine-having I an electric starting motor; switch'means .operable tc'connecta load circuititoia normalrsource of electrical eenergyz'in response tc predetermined-w? condition. "of energizati'on :ifrom said normal source and operable upont-a 'reduction inizsaid condition to'disconnect the'load circuit from-said normal :source' and; connect it rto -:the auxiliary? 1 generatonrtime' delay means" operable-"immediately in response to the reduction in said" con dition, timing meanseoperable responserton operation ofthe'rtimeadelaysmeans to efiectccone: nection .of the 'startingrmotoratoa source .ofaele trical' energy -fora 'predeterminedcftime, Ead'dl .tional' timing-means operable tO'Z PIGYGIItTTCOHP? nectionot the. starting :motorto? the sourcefor: a, predetermined -.-time-,-:-a -master control relay. operable in response to connection :of" the-"motor. to the source for controlling. the: timing-means; control means responsiveto-starting of the engine forv effecting disconnection -of the" startingn'motor from the source and means responsive'to the te minalwvoltage of the generator to-maintain-the' starting motori disconnected; esaid' time-idelay; i -means being operable a predeterminedzetime after energization ofthe lload-.-circuit to reset thestim ingand counting means for providinga newrcyclex: for subsequent starting of the motor. 1

7. In ,a control system-;-. anrauxiliaryi generator" driven. by an internal combustion engine having a a starting motor switch, means 1 normallyt-ope able to connect; a load .circuitto a (normalisource; of electricalsenergylin response to a predeter mined voltageof .said normal source saidiswitch means. being roperableewhen/the; voltage of-Jthe. normal source falls below a predeterminedrvalue to connect-the v-loadicircuiti -to .the :auxiliaryz gen erator, switch means operable to connect;.the;,. startingmotor toca sourceeof electricaleen-ergyr I for .a predeterminedtime, control Jneans 'respon sivetto a predetermined value of current supplied to the starting .t moton, timing means-miserable after a predeterminedtime to rrend'ervthe switchziv means inoperative, additional i-timings.-rmeansa-- operable .to maintain. the switch means .inopera-t tive for a predetermined time, counting means operable to provide a maximum number of operations of the switch means in a sequence, a master relay responsive to operation of the control means for effecting alternate operations of said timing means and additional timing means and initiating operation of the counting means, means responsive to a return of the control means to the inoperative position during operation of the timing means for rendering the switch means inoperative, and means responsive to operation of the switch means upon restoration of the predetermined voltage condition to the normal source to reset the counting means.

8. In combination, an auxiliary generator connected to an internal combustion engine having a starting motor, switch means operable in response to energization of a normal source to connect a load circuit to said source, said switch means being operable upon deenergization of said source to connect the load circuit to the auxiliary generator, control means operable to connect the starting motor to a source of electrical energy for a predetermined number of times at predetermined intervals, means responsive to starting of the engine during connection of the motor for effecting disconnection of the motor from the source, and time delay means operable after the engine runs for a predetermined time to reset the control means.

9. In a control system for a starting motor of an internal combustion engine, switch means operable to connect the motor to a source of electrical energy, timing means operable to provide timed operations of the switch means, counting means responsive to operations of the switch means to limit the number of timed operations of the switch means, and means responsive to a predetermined reduction in the current drawn by the motor during a timed operation of the switch means operable to interrupt said timed operations.

MAURICE E. REAGAN. WILLARD A. DERR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,662,366 Cosgray Mar. 13, 1928 1,776,683 Larkin Sept. 23, 1930 1,981,859 Frese Nov. 27, 1934 2,324,005 Larkin July 13, 1943 2,374,251 Wallace Apr. 24, 1945 2,384,135 Scherry 1-..--- Sept. 4, 1945