US1288502A

US1288502A - Selective time-limit controlling device for electric switches.

Info

Publication number: US1288502A
Application number: US23401518A
Authority: US
Inventors: George A Burnham
Original assignee: S B CONDIT JR
Current assignee: S B CONDIT JR
Priority date: 1918-05-11
Filing date: 1918-05-11
Publication date: 1918-12-24
Anticipated expiration: 1935-12-24

Description

G. A. BURNHAM. SELECTIVE TIME L|M|T CONTRULUNG DEVICE Fon ELECTRIC swncHEs,

APPLICATION FILED HJLY 2|. l9ll. REHEWE) MAY Il. 1918 J SHEETS-SHEET l.

Wzesses: 4 25M l T- O h a' 42. 5

I 74 61 il 73 4] 40 f f' ""Gf//zwfzlorr may G. A. BURNHAM.

smcuve TIME LlMn comnmuws nEvacE Fon ELECTRIC swncHEs. APPLICATION FILED JULY 2|* 19H. HENEWEU MAY Il. lglB.' 1 ,288,502, Patented Dec. 24, 1918.

3 SHEETS-SHEET 2.

WL' fwsses; [Ime/250W f ma@ y fww G. A. BURNHAM.

SELECTIVE TIME UMhIT CONTRQLLING DEVICE FOR ELECTRIC SWITCHES. APPLIcATIon FILED xuLY 2|.|91|. RENEwEn MAY 11.1913.

1,288,502. Patented Dec. 24,1918.

3 SHEETS-SHEET 3.

all of UMTED STATES vPATENT onirica.

GEORGE A. BUNHAM, OF SAUGUS, MASSACHUSETTS, ASSIGNOR TO S. B. CONDIT, JR., 0F BOSTON, MASSACHUSETTS.

SELECTIVE TIMELIMIT CONTROLLING DEVICE FOR ELECTRIC SWITCHES.

Specification of Letters Patent.

Patente :l Dec. 24, 1918.

Application tiled July y21, 1911, Serial No. 639,763. Renewed Kay 11, 1918. Serial No. 234,015.

To all whom it may concern:

lie it known that l, (EonoE A. BURNHAM, a citizen of the United States, residing at Saugus, in thc county of Essex and State of Massachusetts, have invented an Improve# nient in Selective Time-Limit Controlling Devices for Electric Switches, of which .the following is a specification.

This invention relates to time-limit controlling-devices for electric-switches. Heretofore time-limit controlling-devices `for `electric-switches huw .been devised including operatingmeans for the switch requiring a prolonged period of time to operate the switch. In some instances, the ,time-con trolled element of the operating-means is moved at a constant speed through a definite interval of space, hence, the period of time consumed by it is the same regardless of the strength of the overload. In other instances the time-controlled element is moved at af varying speed according to the strength of the overload, so that the period of time consumed by it varies according to the strength of the overload, being less on' a heavy overload than on a light overload. Furthermore,

the operating-means for the switch has been made manually adjustable so that the timecontrolled element is moved throu h an iny tcrval of s acc'o greater or less ength in operating t ic switch. So far as I am aware,

these controlling-devices made by others have failed to be' selective in action,

notwithstanding their different normalsettings, upon the occurrence of a very heavy overload, as, in such case, they will all operate their respective switches simultaneously or substantially so and unnecessarily open the circuits.

This invention has for its object the construction of a time-limit controlling-device for electric-switches having operating-means for the switch which requires a prolon ed period of time to operate the switch, ut which is adjustable automatically to vary said period of time according to the strength of the overload. My present invention is applicable to either type `of controlling.- device above referred to,v,and for: purposes of illustration both forms of controlling-de# vices are` here shown, one wherein the timecontrolled element is controlled by the overload cin-'rent and moved at a constant' speed,

and the other wherein the time-controlled element is controlled by the overload current i troller for the switch and and moved at a speed dependent upon the strength 'of the overload, up to'a predetermined current value, and on overloads of higher currentl values is moved at a constant speed regardless of the strength of the overload, so that in any event'ay prolonged period of time is maintained. For preference I also select a type wherein the operatingmeans is manually adjustable to vary the period of time consumed by it in oper .ting the switch, so that each time-limit controlling-device may have a dijtl'erent normal setting from others4 which are arranged in the circuit. i

In the present embodiment of my invention automatic variation of the operating means is accomplished by varying the length of the interval of space throughwhich the timecontrolled element4 moves, by means controlled by the overload current, but my invention is noty limited to -accomplishing this result in this manner, as I desirer to include within the spirit and sco e of my invention any means to automatica] y adjust said operatmgmeans to vary the time consumed by itin completin its operation tooperate the switch, which 1s controlled by theoverload current, and, especially when said o eratingmeans is also actuated by the overoad current. 4 In the present embodiment of myinvention the operatingmeans comprises ,a conan operatingdevice for said-controller, and said control- `ler comprises an 'electro-magnet to operate the switch., and the o erating-device comprises a cifcintcloser fldr the circuit'of-'said' electro-magnet, both members of said` cir- .cuit-closer being movable toward and from the other, movement of one member bein 4automatically controlled by the overload current to vary the other member,v to reduce the intervalof! s'pace alnd ,correspondingly reduce theV time required ffm; 'the mem rs to enga-ge ajdgclose theil-,cuginit`l `of the controller to operate the oa'llgcli,"while the other member is' operated by .an electric-motor, controlled .bythe overload, at a constant or4 variable speed according to the construction of the motor, or according to the current-value of the overload.

Figure 1 is a side elevation of a time-limit controlling-device for electricswitches, em bodying this invention.

its position with Arespect to elevation of the motor and circuit which may be employed.

F ig. 5 4is a detail of the operating-means foi' the switch and a diagram of a modified form' of electric-motor and circuit which miy be employed.' 4 y eferring to Fig. 4, wherein a single linccircuit is shown as a simple in anner of illustrating niy invention, 20 represents, the circuitV or 'line 'wire, `end 21,' a switch of any suitableieoiistriictioin but preferably of a type adapt'edto bei operated automatically to open thecircuit, and inanuall to close the same. A snap-switch of usua construction is here shown,'he'viiig a hand-lever 22, and an' iictuating-spriiig :23. This is the switch which thetime`li|nit -controlling-device forming the subject-matter of thisl application designed to' operate aut'oniatically,toopen the iciicuit20. The time-limit controlling-device involves operating-means fo; the switch` and `means responsive to an overload current to actuate it, or to control its operation, and means also responsive 4to theoverload current to adjust itwhereby thel period of time required for it"to` operate the switch is 'reduced accordingh strength ofthe current. Ashere s own for' the purpose of illustrating my invention controller of the electrica y type, which is adapted,` when operated,to open the switch, and an'op'erating-devi .fortheircuit of said switchecontroller, which' requires a prolonged period of .time to complete its operation to operate the switch-controller, and

,said Voperating-meansk com 'rises e switch.

said operating-device is,l automatically ad' V `justecl byl Ineens responsive to the. overload current, and isalso actuated by meansire-V sponsive to theoyerloiid. current.

1 The switch-controller here4 shown consiste of an electro-magnet 24, ,connected in a batterycircut 25, the, armature of which is'connected to a lever.28,'secured to e pivotshaft,"'and to saidfshaft is secured a' Short ari'n'- 291 which is designed to engage` and operate e snap-switch to open' the`circiiit 20,Uupon energization of ,the magnet,

4The operatingdevicegfor the switchcontrollerfs-here shown, consists of a -circuit controlling-device. for the circuit 25. Lsaid ,eircnitf controllingrdevice coinp1'ising` two members, both ofwhich are movubleto'wiird and from each other, :and yone,,of, tlie'iiiii-i time-controlled, sou's to'.' require a prolon "ed period of time to move and engage the ot er ,.niember.l 4 One of said circuit-closing meinbers 'comprises'two circuit-'contacts 2Q, 27, adapted .to be connected with the circuit 25, and said'contacts are arranged on au-arnr 30, of insulating material, secured to a pi\otshat't 31, bearing a pinion 3'2, which is in mesh with a toothed-sector 33, pivoted Aat 34, and connected h v a link 35, with the armature of a solenoid 75. which armature is shown in Fig. 1 asin its normal elevated position, and in Fig. -t as moved downward in response to the pull of the winding of tlul solenoid. Said solenoid is included iii a circuit 70, of the secondary-coil Tl, of a transformer, the |n'imary-coil 72, of which is included in the circuit 20, so that said solenoid is responsive to an overload upon the circuit 20. which is reduced hy or through a transformer. Said solenoid constitutes the means which is responsive to an overload-current and which is employed to adjust the. operating-ineans for the switch, by moving the circuit-closing niember 26, 2T, so as to vary its distance from (he coperating circuit-closing member. accordin to the movement of the armature of the soenoid. On a light overload said circuitclosing .member 26, 2T, will bc moved coun ter-clockwise a short distance, as shown in Fig.4, and on a heavy overload, will-lic. moved a correspondingly greater distance, although it will hc understood that movenient of the core of the solenoid is checked when it arrives at. or about the middle of the winding of the solenoid. The coperat ing circuibclosing member of the circuit- `elosingdevicc is time-controlled and consists'of a yoke or arm 40, arranged to be moved rotai'il in a-vertical plane, having at" its extremity fi cross-piece or pin 41,

which, when the :Deke or arm arrives at the end 'of its rotar),y movement is adapted to cngage the circuit-

contacts

26, 27, 4to thereby close the circuit 25 of the switch-controller.

Said yoke or arm is mounted loosely on a shaft 42, to which a worin-wheel 43, is secured, and means, as a screw 44, is provided ,for adjusti'ibly connecting said yoke or arm ielii'tiveihereto. jAs the worm-wheel is re- Avolved in' tlie'direction of the arrow Fig. 1,' said yoke or arm ismoved by it through au iiitervul of space, which is variable in length according to.' its connection with the worm wheel to engage the circuit-contacts 2li, 27, and the relative position of the contacts 2e, 27.

The Vmovement' of thc worm-wheel and yoke or arm to close the circuit 25, of the switch requires a prolonged period of time and such movement'is controlled by means responsive to the overload, so that said circuit-closing nember is controlled by the overload current.

As a means to move the \vormwhecl and the yoke or arm an electric-motor is cmployeft In Figs. 1 to 4 inclusive, the electric-1no tor is constructed and arranged substantially the same as shownin my Letters Patent, No. 1,011,716, dated October 15, 1912, if being of the series type or having the gcneral characteristics of a series motor, and constructed and arranged in such manner that its magnetiocircuit aiid windings are so proportioned as to require an overload of approximately three times the full load of the circuit controlled by the switch to cause the motor-armature to attain its speed-li1nit,

although a lesser overload will cause the motor-aru'iature to revolve at a slower speed proportionate to the strength of the over load, and a greater overload, meaning an overload in excess of that requiredto cause the motor-armature to attain its speed-limit will cause the motor-armature to revolve at its maximum speed regardless of the strength of the overload. Said electric-motor is included in a transformer circuit 70, so as to be responsive to thc overload, being controlled and operated by it. In Fig. 5 I have 4shown an ordinary con stant speed motor connected in a battery circuit, which is controlled by the overload current but operated by thebattery current. So far as my present invention is concerned, either type may be employed or any other Suitable type, as the variation in the pilolonged period of time consumed by the timed-element of the `operai;ing-means is automatically controlled by means independent of the motor and is operated or con trolled by the overload. i Referring to Figs. 1 to 4, 48 represents the armature of th motor, which is supported in suitable bearings, and one end of the shaft of the armature is extendedas at 49, and is threaded to form va Worm. The worm-wheel 43 is arranged beneath said worm, but is normally out of engagement therewith, and is supported by a movablt` member whereby it is movable into and out of engagement with said worm. Said worm serves as the means to drive the worm-.\vheel.

and therefore, constitutes the actuator for` the operating-device. The engagement of 'the operating-device with its actuator is con'- trolled by the current which operates the motor, and herem said worm-wheel 43, 1s

supported by an extension of the lower 'part of the ieldframe of the motor, which is made movable with respect to the upper part thereof, whereby the worm-wheel is moved into and out. of engagement with its actuator. The field-frame of thc motor is or may be made in two parts, or mav ha vc a Inovable part in connection with it` and` as bertl shown.4 said frame is divided on a horizontal line, representinglr the upper part and 5ll thc lower part` and said parts art` hingcdly connected together at 52, so that the lower part is movable toward and from the upper part, and the upper part is hcld slationarilv by being connected to the support 53. With the exception of making thc field-frame in two parts it may bc constructed, generally speaking, in any \\'clllnio\\'l or suitable manner, to support the field-coils. Movement ofthe lower part 51 in a direction away from the upper part is limited by au adjustable yielding stop comprising, as shown in Fig. 1, a pin 55, extended through an ear 56. arranged thereon, which engages a spring 57, resting against a fixed. abutment 58, which may be a downwardlensio'n ot' the upper part. The lower end of the ear 56 has a hole through it for a bar (it), which is horizontally arranged and secured to thc extension' 58, and which projects through said holel for a considerable distance, and a. i

spring 59 is arranged on said bar between the ear and a nut (51, adjustably connected with the bar, whichA exerts its pressure upon the ear in a direction to move the lower part of the frame downwardly, and upward lnoveinentoftlle' fraaie acts to compress said spring so that such movement is rcsisted by the spring, and by adjustment.

ofthe lspring greater orlcss force may' be required to lift the frame. The bar 60 may be calibrated. if desired, to indicate in amperes the force required to lift thel frame by the magnetic influence. due `to the current traversing the field-coils ot' the motor, and the motor to act as a magnet. Thus 4the spring 59 not only acts as a retractile spring to assist gravity in moving the part 5l away from the part 50, but. also imay be employed to determine the energy required to lift it, and hence serves as au adjusting-device foi-,the motor, whereby it, may be caused to move the operating-deviec into engagement with its actuator upon an overload of a given value, or in excess ot' said value. 'hen the lower part of the field-frame is in its lowermost position. being removed from or remote from tht` upper part` as represented in Fig. 1. said wormwbcel is removed from engagement with the' worm` and when said lower part of tlr: field-frame is in its uppermost position, as represented in Fig. 3, said \\'orm-wln\el is in engagement with the worm.

The motor is or may 'be arranged in the transformer circuit T0. but is` normally short-circuiied by a switch or circuit closer, the fixed members 7?), of which are en gaged by a plate T4, connected with thc annature ot' the solenoid 75. When said sole.-l

noid pulls down its armature due to-an overload on the circuit 2U, the circuit-closer 73, Tt, will he operated to open the shortcircuit of the motor. as shown in Fig. 4. so that the motor will be operated 'by the overload current, through' the transformer; and the lower part of the lieldvframo will be attracted toward theI upper )art thereof to move t'he operating-device or the 'switchcontroller .into engagement with its actua tor: and the arm 4U will be moved rotarily cloelnvise toward and into engagement with the cireuit-contzu-ts 2G. 2. to cause the switch controller to operate the switch and open the circuit :20. ln case the overload eurrentvpasses over the circuit for a short period of time and then ceases, and such period ot' time is insullicient to move the operatiiig-device far enough to cause. its arm l() to engage the circuit-

contacts

26, 27, then as soon as said overload ceases the parts will be restored to normal by gravity. The, distance which the arm 4U moves depends upon the position of the circuit-contaets 2G, 2T. with respect thereto, and the posit-ion of said contacts is controlled by the overload through the 'solenoid 75. to thus control the length of the period o f time. By controllingr thc length of the prolongedpe- .riod of time. required for the operatingmeans to operate; the switch by means operated by th'c overloadis of the greatest importance, as it enables a set of time-limit controlling-'devices to be selective regardless of the. strength of the overload.

By the means shown iu Figs. l to l. the. variation in thc'pe-riml o-f` time, occurs at both ends thereof, as for instance. the movement of the arm 40 is varialblc according to theeurrent value yof the overload u) to a predetermined current value. and is t elinite. o n overloads of higher current values, and theJ distance said arm. nuves is variable according to the position of the arlu 3() bearing the contacts` 26,27. aml movement of said arm 30 is variable according to the. current value ot" the overload u i to a predetermined current value` and is del'inite on overloads of higher current values. 'l`he re-latively stationary contact-memher Il() will onl \I approach the retarded contact-lnem'ber l0 a limited distance, so that in any event.

with a given setting of each relay., there.-

will be a certain pcriodof time elapse. het'weml thc occurrence of the overheid and the tripping of the circuit-hrenker. which will he constant for each Arelay above 'certain values of overload. and lio-matter how much higher the'ovexfload may he. and also difierent for each relay in the. system according to' its setting. This result will be obtained also by the form of ap iaratus shown in ,Fig 5, and with either orm of apparatus the ohartlincs will he Indicated by inverse,

curves followed bylstraight lines, which will not intersect on a heavy overload, as for instance, on an overload in excess of three times the full load of the current which is controlled by the switch. The form of apparatus shown'in Figs. 1 to -l has the advan- ,tage over the form shown in my patent;

aforesaid of providing a very short movement for the contact-member 40, upon the. occurrence of a .Very heavy overload, so that a very short period of time is consu-med, althouvh such period of time is of a substantia yet of definite length, while with the motor of the patent, said contact-Incinber l() moves through thel same arc on both heavy and light overloads, its speed -of movement bolug greatly accelerated on heavy overloads thus the motor in the present form of apparatus need n'ot have as wide a ran of flexibility.

Re crring to Fig. 5, the electric-motor may be constructed tie same as the motor shown in Figs. l and 2, with the exception that its mafrnetic-circuit and windings are proportioned as usual in electric-motors, so that it. is arranged to bc operated at. a constant speed by a battery current or other source of energ In said Fig. 5, the electric-motor is arranged in a battery-circuitl 90. which is closed by the circuit-closin members 73, 7l. controlled by the solenoid T5. so that upon Ithe occurreneeof an overload. said battery circuit is closed and the. motor is caused to operate at a constant speed to more the arln at() clockwise at a con- 100 stantl speed, but the distance said arm moves is varied b v means controlled by the solenoid T5. which means together with the solenoid are substantially the sameC as. shown in Fig.

l. so that the'saine result'is obtained, al- 105 though the variation in the prolonged period i of time occurs at only one end of the period, said variation being produced by thc'action of the solenoid in response of an over-load.

'l`he constantspeed-motor, being included in 1,10

a lmtter v,circuit or driven .by an independent. source of electric enervy, might itself act as a definite timc-lii'uit relay, babas here shown. it will not operate the switch-operating means 'except in conjunction with the 115- solenoid by which the time of operation is varied.: cording to the current value of the overloiilldnp to an overload of a predetermined carrait value. and by which the time of operation will be. definite' on over- 120 loads ofhigher current values. Hence,"inv the forni of apparatus shown in Fig. the elia-rt lines 4will :be 'indicated by inverse curves of a pitch sliglxtlyditf'ering from that of the aforesaid apparatus,"and then'by 125 straight' lines which will not intersect on heavy overloads. ln said Fig. 5, the. plate4 74'. normally occupies a position above the contacts 73, and w'ill be moved downward into engagement with said contacts upon a 130 downward movement of the core of the solenoid. and in view of the fact that engagement is required upon the occurrence of a light, as well as a heavy overload, said plate is loosely arranged on the stem connected with the core of the solenoid, and is held b v a spring'so that movement of the core ot' tbesglvenoid independently of the plate is permitted"upon the occurrence of heavyv overloads` while the plate is engaging the contacts T3. Upon the occurrence of a light overload. the core will be moved a short distance suflicient to cause the plate Tt to engage the contacts 73. and the arm 50. to be moved counter-clockwise a short distance only. asrepresented in Fig. and upon. the occurrence otl a heavy overload, the core of the solenoid will be moved farther, but the plate il will still engage'said contacts and will there remain while the core moves independently of it; although downward movement ot' the core is limited. as here shown, when it arri ves at or about. the middle of the solenoid, and will not be moved fartherrre-l gardless of the strength of the overload. This form of apparatus, shown in Fig. wherein a constant speed actuator is employed for one of the contact-members, and a variable actuator employed for the other contact-member, which variable actuator is arranged to be controlled by an `overload current in the manner herein set forth, forms the subject matter of a divisional application No. 873,062. tiled November 19, 1914.

In lieu of employing an elcctric-motor to operate the operating-means for a Switch, any other suitable device may be employed. which is controlled by an overload current, and is arranged to operate said operatingmeans at a variable or constant speed or both.

adjust one of lsaid members to reduce said period of time according to the strength of the overload` and means controlled by the overload current to actuate the other member :it a variable: speed according to the strength ofthe overload, substantially as dcscribed.

ln a selective time-limit controlling-device for clcctrioswitches, the combination of switch operating-means requiring a prolonged period ot' timcto operate the switch, including cooperating contact-members. means controlled by au overload current t0 adjust one of said members to reduce. said period of time according to thc strcngth'of thtI overload, and meansl controlled by the overload current to actuatc the other lilcincontact members, means controlhal by an overload current to l adjust one of said members to reduce said period of time'according to the strength of the overload. and an electric-motor controlled by the overload current to actnate the other member at a variable speed according to the strength of the overload. substantially as described.

4. ln a selective time-limit controlling-device for electric-switches, the combination of switch operating-means requiring a pro- -longed period of time to operate the switch, includingl cooperating contact i'nembers, means controlled by an overload current to adjust one of said members to reduce said period of time according to the strength of the overlo d. and an electric-motor c0i1- trolled by lhe overload current which is constructrl and arranged to actuate tlieother member at a variable spoed'according tothe current value of the overload up'to a predetermined current value and at a definite speed ref'ardlcss of the strength of the overload on iigher current values, substantially as described.

ln-a selective time-limit controllngfdevice for electric-switches, the combination of switch-operating-mcans requiring a pro` longed period of time to 'operate the switch, including cooperating contact-members, 105 means controlled bylan overhaul in'rcnt to adjust/one of said members to reducefsaid` period of time according tothe Vstrclncrth of the overload, and means controlled by the overload current to actuate the other lmem- 110 ber. at a variablesspeed according to tho strength of the overload, lboth membersl being permitted to return to noi-malimmediately upon cessation of the overload, substantially as described.

6. A selective timclimit controlling-device for electric-switches including a. controller fortho switch, an `operating-device for' said controller comprising Vtwo members, onle ofwhiehhis time-co`ntrolled', means con: 120 trolledy by `a| oyerloadwalrrent to actuato said tilnefcontrolled` member at a variable speed according to tho strength of the overload, and means controlled by the overload for said controller comprising.r two members, one of which is time-controlled, means controlled by an overload current to actuate the timewontrollcd member at a variable speed up to a predetermined current value and at u definite .speed on higher current values, and means controlled by the overload current to movc thc other member toward the time-controlled member, Substantially as described.

8. .selective time-limit controlling-devicc for electric-switches including` a con troller for the switch, an operating-device for said controller comprising two members, one of which is time-controlled, an electricmotor controlled b v the overload current to actuante said time-controlled member, and means controlled b v the overload lcurrentI to more the other member toward the timecontrolled member, substantially as described.

9. A selective time-limit controlling-device for electric-switches including a controller for the switch, an operating-device for said controller comprising two members, one of which is time-controlled. an actuator into and out of engagement with which said time-controlled member -is movable, means controlled by the overload current to move said time-controlled member into and out of engagement with its actuator, means con trolled `by .the overload current to drive said actuator, and means controlled by the overload current to move the other member toward the time-controlled member, substantially as described.

10. A selective time-limit controlling-device for electric-switches including a controller for the switch, an operating-device for 'said controller comprising two members, one of which is time-controlled, an' actuator into and out of engagement with which said time-controller member is movable, means controlled by 'the overload current to move said time-controlled member into and out'of engagement with its actuator, and an electric-motor controlledl by the overload current todrive said actuator, and means controlled by an overload current to move the other member toward the 'timecontrolled member, substantially as described. C

11. A selective time-limit controlling-de` vice for electricswitches including?. a controller for the switch, an operating-device for said controller comprisin two members, one of which is time-control ed,` means con'- tr'olled by an overload current to move one' of said members toward. the other to' redute the time requiredfor the timecontrolled member4 to complete its operationfmearis to .adjust one of the members to vary the len th of said' period of time, and meanscontrol ed by an overload current to actuate the timedescribed.

controlled scribed.

12. A selective time-limit 4controllingzfdcvice for electric-switches including an electro-magnetic controller for the switch. n circuit-closing device for thc circuit of said controllercomprising two members, one of which ie time-controlled, means controlled by an overload current to move one of said mcmbers toward the other to reduce the time required for the members to engage, und means controlled by the overload current to more the time-controlled member, substantially as described.

13. A selective time-limit contrr.)llin, lcvice for electric-switches including un electro-magnetic controller for the 'switch` a circuit-closing device for'the circuit of said controller comprising two members, one of which is time-controlled, means controlled by an overload current to move one of said members toward the other to reduce the time requiredfor the members to engage, means to adjust one of the members tovary the length of said period of time, and means controlled by the overload current to move scid time-controlled member, substantially as de scribed.

14 A selective time-limit controlling-de- -vice for electric-switchesincluding an electro-magnetic controller for the switch, a ci rcuit-closing device for the circuit of said controller, a solenoid responsive to an overload to` move one member of said 'circuit-closing device toward the other member, and means controlled 'by the overload current to more said other member toward the first named member to close the circuit` substantially as member. substantially as de- "hoid responsive to an overload to move 'one tro-magnetic controller member o'f said circuit-closing device for ward the other, and an electric-motor rc3, sponsive to the overload to movettbc cotleiff m'ember toward the 'first named men'i'ber close decima, Sebstancniy as desd-inea.

16. A selective time-limit controlling-db vice for electric-switches including a ebntroller for the switch, a circuit-closing device for the circuit of said controller, a solo1 noid responsive to an overload to move one member of said circuit-closing` devicctoward the other, and an electric-motor responsive to the overload to move the other member toward the fist named member to close the circuit at a' speed dependent upon the strength of the overload, substantially as describ d.A

17. A selective time-limit controlli11g-dcn vice for electric-s|witchesincluding an elecfor the switch, a circuit-closing device for the circuit of said controller, means responsive to an overload to move one member of said circuit-closing device toward the other member to reduce the time required for the members to engage. an actuator for the other member into and out of engagement withwhich it is movable, meansI controlled by the overload to move saidotlier member into engagement with its actuator, and an electric-liiotor to drive said actuator, substantially as described.

18. In a selective tiiiie-liinit controlling device for clectric-switclies. the combination of switch operatinganeans including movable cinitacbniemltx'rs. one of which is time. controlled, means controlled by an overload current arranged to actuate the tinie-coiitrolled member at a speed proportional to the current value of the overload up to a predetermined current value and at a definite speed on overloads of higher current values. and means controlled b v the overload current to move the other member toward the time-controlled member varying distances according;` tothe current value ofv tbe over; load up to a predetermined current value. and definite distances on ovcrloads of higher current values, substantially as described.

19, In a time-limit controlling-device for electric-switches,- the vcombination of switch operating-means including movable contaetmembers, one of which is tinie-contrt'illed` and means responsive to and controlled by an overload current to move the vother inember toward the time-controlled member a' variable distance according to the current value of the overload up to a predetermined current value, and a definite distance on overloads of all higher eilrrent values, and,

means to move the time-controlled membriinto engagement with the other member in any position it may occupy. providing overload condition continues, substantially as dcscribed.

20. In a time-limit controlling-device for electric-switchcs, the combination of switch .operating-means. time-controlled means associated therewith including two contact members, a solenoid also'associat-ed with said switch opcratingmeans, thecorc-piecc of which is movable in response to an overload a variable distance according to the strength of the overload, np to a prede-termined current value, and is movable its maximum distance on all overloads of higher current values to correspondingly move. one of the contact members, and means to move the other ciuitziet-member into engagement. with the aforesaid contactinember in any position it may occupy. upon the continuance of abnormal conditions, substantially as described.4

2l. The combination with an electrical installation, of a relay comprising a movable member. means whereby said member is moved at a speed which varies as a direct function of the rate of flow ot current in said installation, and means copcrating with said movable member for interrupting the How of current in said installation when said member has moved from an initial position a distance which is an inverse measure of the rate of flow of current in said installation.

22. The combination with anelcctrical installation, of a relay comprising a movable member. means whereby said member is moved at a speed which varies as a direct function of the rate of How of current in said installation, a second movable lmember arranged to move toward and in the path of movement of said first mentioned movable member, means for moving said second meniber tow: rd said first mentioned member a `distance which is a direct' function of the lrate ofiow of current in said installation, and means controlled by the engagement of said members for interrupting the How of current in said installation.

..3. The combination with an electrical installation, of a relaycomprising a movable member, means adapted to novc said member at a speed which varies as a direct function of the rate ot' tlow of current in said installation, means for causing said last mentioned means to move said member when the rate of fiow of current in said installation exceeds a predetermined amount, and means cooperating with said movable member for interrupting the How of current in said iii stallatioii when said member has moved a distance which is an inverse measure of the rate of flow of current in said installation.

24. The Combination with an electrical installation, of a relay,r comprising a movable member. means adapted to move. said member at a speed which varies as a direct func tion of tbe rate offtlow of current in said installation, means for causing said' last mentioned means to move said member `when the rate of How of current in said installation exceeds a predetermined amount-.a sec. ond movableinember arranged in thepath of movement ofsaid first mentioned mem ber, means for moving said' second member toward said first mentioned member a distance which is a function of the rate ot flow of current, and means controlled by the engagement ofsaid members for interrupting the How of current in said installation.

25. The combination with an electrical in,- stallation. of a relay comprising a movable member havingan initial position, means adapted to move said member at a speed which varies as a direct function of the rate of How. of current in said. installation` means for causing said last mentioned means to lit.

move said member when the rate of flow of current in said installation exceeds a predetermined amount, means adapted to return said movable member to its initial po sition when the rate of How of current is less than said predetermined amount, and means cooperating with said movable member for interrupting the flow of current in said installation when said member has moved a distance which is an inverse measure of the rate of How of current.

26. The combination with an electrical installation, of a relay comprising an electric circuit, a movable contact in said circuit, means adapted tomove said contact at a Saeed which varieslas a direct function of the rate of llow of current in said installa tion, means for causing said last mentioned means to move said member when the rate of fiow of current in said installation exceeds a predetermined amount, a second movable contact in said circuit arranged in the path 'of movement of said first mentioned contact, means for moving said second contact toward said first mentioned contact a distance .which is a function of the rate of flow of current, and means controlled Vby the en- '.gagementof said contactsfor interrupting the ,flow of current in sald installation. 30,

27..The combination with anelectrical installation, of va relay comprising electromag- ,netc'means electrically connected tothe installation and adapted 'to produce a n1agl "netc field proportional to the rate of flow vof ncurrent in' said installation, an armature rotatably mounted in said magnetic field, a movable memberadapted to he operatively connected to said armature when the rate of flow of current in the installation exceeds a predetermined amount, and means cop- .yerating with said movable member for in- `terruptmg the flow of current in said 1nstallation when said member has moved a distance which is an inverse measure of the Ainstantaneous rate of flow of current.

28. In combination with an electrical in- `stallation, of a relay comprising electromagnetic means electrically connected to the instullalion und adapted to produce a magnetic. field proportional to lllc rate of ll'ow of cm'- rcn( in said installation1 an urnnitnrc rotatably mounted in said magnetic field. n movable member adapted to be operatively connected lo said '.lrnuiture when thc rato of flow of current in the installation exceeds a predetermined amount, a second movable member arranged in the path of movement of said lirst mentioned member. means for movin#r said second member toward .said first mentioned member n distance which is a function ol' the inslantancmls rate of flow ot' current in thc installation, and means controlled by the engagement of said mom bers for interruptingr thc ilow of current in said installation.

ifi. 'l`llc combination with an electrical installation. of a relai' comprising;A two cooperating movable members. means for moring one. of said members toward the other member at a speed which is a direct fnuction of an electrical rlmractelistieY ol the in stallation, means for moving the other mem` ber toward its cooperating member a distance which is a function of an electrical characteristic of the installation, and means controlled by the engagement of said members for interrupting the liow o current. in said installation.

30. A relay comprisingV in combination an electric circuit, two movable circuitI closing,r contacts included in said circuit, means for moving one of said contacts toward the other contact at a speed which varies as a fuuction of an electrical characteristic of an electrical installation, and means for moving the other contact toward its coperating contact a distance. which is a function oi an electrical characteristic of the installation.

ln testimoni7 whereof. I have signed my name to this specification, in the presence of twosubscribing witnesses.

GEORGE A. BURNHAM.

lVitnesses t B. J. Norms, lol. B. DAVIS.