Патент USA US2107821код для вставки
Feb. 8, 1938. _l> E FARRELL 2,107,821 AUTOMATIC SWITCH FOR ELECTRIC SERVICE LINES Filed Oct. 1_8, 1934 gmc/YM JosçphEZF’a/rrel l , x. MW 2,107,821 Patented Feb. 8, 1938 ' UNITED STATES PATE-NT OFFICE 2.107.821 AUTOMATIC SWITCH FOR ELECTRIC SERV ICE LINES Joseph E. Farrell, Washington, D. C., assigner to Automotive Devices Corporation, Washing ton, D. C., a corporation of Delaware Application October _18, 1934, Serial No. 748,959 11 Claims. (Cl. 200-89) This invention relates to a device for normally maintaining an electrical service line circuit closed. but which automatically functions upon the existence of unusual conditions in the line, 5 such as surges resulting from a short or over load, to automatically open the circuit for the purpose of protecting electrical apparatus in cluded therein. \ A general object of the invention is to provide 10 a novel device intended to obviate the use of a fuse of the type including a .strip of metallic one of its essential elements a construction where in a barrier of insulation is automatically and positively interposed between the switch _con tacts when the device is called upon to function to open the line thereby eliminating an air gap between the switch contacts and keeping them adequately separated and insulated until con ditions are such as properly to permit 'of restor ing the circuit. A further and distinctive object of the inven-I tion is to provide a novel arrangement whereby after the device has once functioned to open the line, the barrier of insulation will not only be generally unsatisfactory for numerous reasons. ' maintained or kept between the separated switch In the first place when a device of this type has contacts but it will be impossible to manually 15 reset the switch until after the unusual condition once functioned it must be discarded and re placed by a new one. Consequently, this causes in the line has been remedied. That is to say, alloy which melts or breaks upon the occurrence of the unusual condition in the line and which is ~ not only a waste of the article itself but fre quently requires much time and labor to locate where many circuits are involved, and also 20 causes inconvenience and delay due to loss of the circuit while the replacement is made. Therefore, the present invention contemplates an improved device of the electromagnetic switch type which may be used indefinitely after 2 Ol it is once installed by merely manually resetting the switch portion thereof to restore the circuit after it has been automatically opened to safe guardV the line. While electro-magnetic devices of this general 30 type have heretofore been used, nevertheless many of them are open to the objection that they do not reliably function and are particu larly objectionable because after they have func tioned to open the line circuit, the switch ter minals are left unguarded or unprotected so that in the event that a subsequent unusual surge oc curs in the line, an arc is produced between the exposed switch terminals due to the fact that they are only separated by an air gap. Also, the movement of the resetting means in an at tempt to reclose the switch will be idle so long as the unusual condition persists. In that connec tion, the invention contemplates as a part of the 20 resetting means a pair of insulated movably re lated elements, one of which carries a manual resetting handle while the other carries the in sulation barrier for separating the contacts, and as long as the unusual condition exists in the 25 line, these two members will be disconnected so that the manually shiftable element may be moved independently of the insulation barrier or cut-olf, and only when the unusual condition ceases to exist in the line will it be possible for 30 these two members to be automatically coupled «or connected to effect the resetting and reclosing of the switch. ' kA further object of the invention is to provide a simple, compact and reliable construction which 35 lendsl itself to an embodiment that facilitates manufacture and assembly and which because of its simplicity‘ and substantial construction will function indefinitely without being removed or 40 disconnected from the line circuit. With the above and other objects in view many devices heretofore used have been open to the objection that the manual resetting means may be operated to bring the switch contacts which will more readily appear as the nature intoengaging relation while the short or other , of the invention is better understood, the in unusual condition still exists in the line with the vention consists in the novel features ci’ con result that if it is attempted to manually hold struction, combination and arrangement of parts', the switch in its closed position in an eifort to hereinafter more fully described, illustrated in reset it while still subjected -to unusually high the accompanying drawing and deñned in the voltage, arcing will also occur which will not only appended claims. A preferred and practical embodiment _of the 50 destroy the switch contacts but in some cases produce an arc of such high intensity that it will invention is shown in the accompanying draw ,j ` flash beyond the limits of the device and burn 0r ing, in which:--, Figure l is a side elevation of the improved otherwise injure the hand of the party endeavor ing to reset the switch. 55 ' ’ Accordingly, the invention contemplates as device; Figure 2 is a top plan view thereof. 55 2 'altr/,ssi Figure 3 is a vertical cross-sectional view i taken on the line 2--3 of Figure 2. Figure 4 is a horizontal sectional view taken on the line 4_4 of Figure 3. Figure 5 is a detail vertical section similar to Figure 3 but showing the switch in open posi tion. ' Figure 6 is a detail vertical sectional view taken on the line 6_8 of Figure 3. Figure '1 is a detail’perspective view of the metallic parts of the switch. Figure 8 is a detail perspective view of the amature member. According to the embodiment of the inven tion shown in the drawing, the same essentially includes in its organization a supporting as upwardly extending rear wall Il. This forma tion provides in eifect a socket for receiving an insulating supporting plate I6. This plate is provided with a slot I1 and having its end op posite the socket terminating at and abutting against one of the sides of the switch contact 9 as will be apparent from Figures 3 _and 5. The upper surface of the insulation plate I8 is there fore ñush with the upper surface of the contact 9 for the purpose which will presently appear. Mounted on the upper surface of the support ing plate Il are a pair of nested telescopically related insulating members which are intended to be connected vor disconnected automatically as conditions require. These insulating members are respectively a sliding contact separator and *barrier block G and a reclosing or resetting yoke ing carried thereby and designated generally as H. Both are normally restrained spring ac B, the latter being fitted with a cover C which tuated members, automatically released.' and 20 is held to the housing by a flanged ring or equiv manually reset. ' 20 ' aient means D. The barrier block G is formed with a body Il Referring first to the supporting assembly A having at its forward end an insulating toe Il it may be pointed out that the same essentially which constitutes the barrier adapted to be in includes a pair of main circuit terminals I and terposed‘between the switch contacts 2 and Il 25 >2 which may be respectively in the form of a when the circuit is open. The rear face of the 25 block is provided with a seat for receiving a coil metallic shell and a center contact 2. The metal lic shell I or its equivalent preferably houses an spring 2l whose opposite end engages with the electromagnet 3, suitably insulated therefrom, wall I5 of the switch frame. The body of the sembly designated generally as A, a switch hous and having at one end thereof an insulation 30 plate or washer 4 while the opposite end abuts block is also provided with a central recess or against one side of the cupped or recessed switch thereof and adapted to receive a detent or latch housing or base B. The center contact 2 is pref 22 which is normally urged upwardly by a spring 23 confined between the underside of the head erably in the form of a bolt whose shank 2l provides a core for the magnet and whose head 35 2b is intended to ilt within a recess 5 at the base cavity 2I having an opening in the bottom 30 of the latch and the base of the cavity while the shank of the latch projects through the opening 35 of the housing so that when a rivet, or its equiv in the bottom of the recess or cavity and ex- . alent, 2c is fitted to the opposite end, the _said center contact will hold the parts I, 2, l and B in tends through the slot I1 to receive a nut 2l. This nut is slidably interlocked with the sides of assembled relation. One end of the coil of the magnet 3 is in contact with the combined center contact land core member 2 as indicated at :c While the other end of the wire forming the a slot 2l in an armature member 2l. The latter is pivoted as at 21 to the ears Il of the switch 40 magnet coil is led upwardly through the bottom of the switch housing B to a suitable conductor 45 member 8 positioned and exposed at the face of the shoulder 1 within the switch housing. As shown in Figures 3 and 5, a portion of the metal shell constituting the circuit terminal I may be extended upwardly as indicated at 8 and bent 50 over or otherwise secured as indicated at l* in frame and the spring-22 ofthe latch urges the armature member away from the head 2"- of the combined center contact and-magnet core 2-2‘, and also urges the latch toward socket 2l of member H.45 The sliding barrier block G is nested within the resetting yoke H which includes an insula tion body 2l having a handle 2l adapted to pro ject through a slot 2| in the cover C and is -also provided with _the side walls 22 whose bottom edges rest on the plate Il to surround and house the shoulder 1. The end 8* of the screw shell may, of itself, constitute one of the switch con ' the sliding switch block G. The body 29 is also tacts, but in the assembly shown, it is preferred provided with a rear wall 32 having an opening for permitting the passage therethrough of the to have the said end Il engage with a station 55 ary switch contact 9 intended to cooperate with a movable switch contact III carried by a spring switch lever II which is preferably formed as a part of a metallic switch frame designated gen erally as F. The switch, of which the parts 9, IU and I I are a part, is designated generally as S, and these parts, together with their supports and control members are preferably arranged and assembled as a unit which may be fitted into the hollow or 65 recessed portion of the switch housing B, above the shoulder 1, so as to rest on the latter when the parts are assembled, and be held in place by the cover C. Referring further to the switch unit S it will 70 be observed that the metal switch frame F which includes the yieldable spring switch lever II also comprises a body portion having a rounded rear wall I2 integral with the arms of the switch le ver and is also provided with a bottom wall Il 75 having the depending perforated ears Il and the spring 2l, the said wall also constituting an abut ment for one end of the coil spring 24 confined between the wall 23 and the wall I5 of the switch lever frame. The spring 34 is of larger diameter than the spring 20 so that the latter is nested within the former. The inside face of the upper 60 wall portion of the body 29 is provided with the keeper recess or socket 2s intended to receive the detent or head 22 of the armature controlled latch. When the detent or latch head 22 is en gaged in the socket 2l as shown in Figure 3, it 65 will be apparent that the members G and H will be interlocked and may be moved together. On the other hand, when the amature 26 is at tracted to the head 2b of the combined core and center contact 2-2‘ as shown in Figure 5, the 70 parts G and H will be free to move independ ently of each other. For the purpose of holding the members G and H in their retracted podtion, when interlocked by the detent 22, the forward end of the upper 2,107,891 wall of the body 29 of the resetting yoke is pro ing of the parts G and H will be held poised in vided with a shoulder Il for engagingwith the their reset position. upwardly extending bail shaped strap II* on the switch lever as, will be observed from Figure 3. Thus, when the device is in use and normal oon ditions >exist in the line, it will be apparent that lthe parts assume the position shown in Figure 3 wherein the part II* of the switch lever is en gaged with the shoulder 2l of the resetting yoke. Likewise, the members _G and H will be inter locked by the detent 22 and the armature 20 will be urged upwardly by the spring 22. Upon the occurrence of a short or overload in the circuit including the present device, the mag net M will be activated and will attract the arma ture 28 against the tension oi.' the spring 22. This movement o! the amature will pull the latch or detent 22 downwardly and> release the barrier block G from its interlocking engagement with 20 the manually controlled resetting member H and the spring 2li will push the barrier block G for wardly so that the insulating toe Il will be thrust between the switch contacts 8 and It. The spring switch lever II is normally biased to the closed 25 position so that contacts 9 and Ill are normally engaged. However, when the short or overload occurs the block G may move forward, after re lease from the member H by the withdrawal of the detent 22, due to the fact that the detent 22 30 at its shank portion can freely slide in the slot 25 of the armature member. When the insulating - ban'ier or toe I9 raises or lifts the spring switch contact I0, it also elevates the upper arched por tion of the strip I Il so as to remove the same from 13 Gl obstructing relation to the shoulder 25 on the re setting yoke H. Therefore, when I Il is moved out of the path of l5, the spring 3l can push the mem ber H to the position shown in Figure 5. In this figure, the parts G and H are in the same rela 40 tive position that they are in Figure 3 except that the insulating barrier or toe I0 of member G is interposed between contacts 9 and Ill and no cur rent can pass between these contacts. I! the undesirable condition persists in the line, 45 it will be apparent that the armature 26 will be pulled to its downward position each time the handle 30 is moved from the full line position in Figure 5 to the dotted line position because the circuit is re-closed between contacts 9 and I0. 50 When this condition exists, it will be apparent that the resetting yoke H is disengaged from the slidable block G so that in event the handle 30 is. moved from the full line position to the dotted line position shown in Figure 5, its movement will be 55 idle so far as resetting is concerned and the spring Il will push the member G back to its former po sition between contacts 9 and III, and which is the “off” position of the switch. On the other hand, if the short, or overload in the line is only of temporary duration and the ar mature 28 is released, it will be apparent that the spring 23 will return the armature to its normal position and consequently the detent 22 will move upwardly into the socket 28. Thus, the parts G 85 and H will be interconnected again and by moving the handle 20 from the full line position in Fig ure 5 to the dotted line position, it will be appar ent that the insulating barrier I9 may be with drawn from between the contacts 9 and I0 and the 70 spring switch lever II will move downwardly to re-establish the circuit. Likewise, when the reset ting yoke -H is retracted, the upper portion of the strap I I* will again become seated in the shoulder 25 so that the entire actuating assembly consist 75 ‘ . ' _ Upon the subsequent occurrence o! a short or overload in the line, the latch or detent 22 will be pulled/downwardly and the spring 20 will thrust the block G forwardly to separate the contacts 9 and III and the circuit will be open. Resetting may be eßecœd again as previously described, and these operations may be repeated indeiinitely if desired. _ From; the foregoing it will be apparent that a distinctive feature of the invention resides in pro viding means whereby the switch contacts will be positively separated and blocked by a. barrier of insulation immediately upon the opening of the circuit. As long as the undesirable condition per sists in the line. this insulation barrier will remain in place and manipulation of the resetting means cannot permanently remove the barrier from its obstructing relation to the switch contacts. On 20 the other hand, if the unusual condition auto matically expires as quickly as it automatically oc curred, then, the device may be reset manually for further use. As long as the insulation barrier re mains between the contacts, subsequent surges o! high voltage current will produce no harmful re sult on the apparatus or on the attendant, thereby increasing the safety factor inherent in the device and substantially eliminating all hazards incident to the circuit being closed while the short per v30 sists inthe line. _ Without further description it is thought that the features and advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that changes in the 35 form, proportion and minor details of construc tion may be resorted to, without departing from the spirit of the invention and scope of the ap Y pended claims. 40 1. In an automatic device for protecting elec tric service lines, a pair of switch contacts, one of which is movable with reference to the other, normally interlocked manual and automatic in sulation means for controlling the movable con tact, restraining means for said manual means which in turn controls said automatic means while both are interlocked, an insulation barrier actu ated by the automatic means to open and sepa rate the contacts when the manual and auto 50 matic means are unlocked, and magnetic means for unlocking the manual and automatic means ., and rendering said manual means incapable of being reset by the restraining means while ab normal conditions exist in the line. 55 2. In an automatic device for protecting elec trical service lines, a pair of normally engaged switch contacts, separate spring urged manual and automatic insulation elements for controlling said contacts, means for normally interlocking said manual and automatic elements, restraining means effective while said elementsare inter locked, means associated with said automatic ele ment for separating and insulating said contacts, and magnetic means for unlocking said manual and automatic elements and rendering said re straining means ineffective while abnormal condi tions exist in the line, whereby the manual ele ment can not be reset. 3'. In an automatic device for protecting elec trical service lines, switch contacts one of which is normally spring biased to engage the other, and means for controlling said ilrst named con tact, said means including a slidable insulation barrier and-a manually operated reelosing mem 4 2,107,821 _ - ber, spring means for urging said members in one ¿ direction, means for normally interlocking said members, means for restraining said members while interlocked against the force of said spring Cà means, electro-magnetically operated means for movement whereby the insulation member in i'or engaging with said movable contact, means for urging said control members in one direction, a latch carried by the control member having the insulating toe and adapted to engage with s socket in the member having the shoulder, a passing between the switch contacts rendersßaid spring for normally urging the latch into the restraining means ineiiective to prevent resetting of the reclosing member while it is disconnected. socket, an armature member in operatlve'rela tion to the magnet, and means for slidabiy con necting the latch and the amature. 9. In a device of the class described, a pair oi switch contacts, one o! which is movable with reference to the other, an electromagnet in cir cuit with one of said contacts, a pair oi’ shiftable telescopically related control members, one of releasing said members Vfor relative independent from the insulation member. . 4. In an automatic device ior protecting elec ‘ trical service lines, switch contacts one oi' which is normally spring biased to engage the other, and means for controlling said ?rst named con tact, said means including a switch opening in sulation member and a manually operated re closing member, means for normally interlocking said members, means for restraining said mem bers while intcriocked, and electro-magnetically operated means for releasing said members from said restraining means thereby to open the switch contacts and simultaneously render the reclosing member inoperative while the electromagnetic means is capable of being actuated by a persist ing overload in the line. 5. An automatic switch for protecting electric service lines including a pair of switch contacts, an electro-magnet in circuit with one switch 30 to be projected between said switch contacts, and the other oi which is provided with a shoulder contact, a pair of superimposed nested and slid ably related spring actuated insulation members, locking means for normally restraining the said members, means attracted by said electro-mag which is provided with an insulating toe adapted to be projected between saidswitch contacts, and the other oi which is provided with a shoulder and a socket, a latch for engaging with a socket 20 in the member having the shoulder, a spring for normally urging the latch into the socket, an armature member having a slot, and a member carried by the latch and having a slidable guid ing engagement in the slot oi the armature member. 10. In a device of the lclass described, a pair of switch contacts, one of which is stationary and the other of which is movable, an electro magnet in circuit with one of said contacts, said 30 movable contact including a spring arm having a contact portion normally adapted to engage with the stationary contact, restraining means net upon the occurrence of an overload in the i line for releasing said locking means whereby one of the members may slide to separate the on the movable contact, a pair oi' shiitable con trol members, a shoulder on one of said members, switch contacts while the other is set free to slide idle with respect to the first mentioned the contacts, an insulating member carried by one oi.' said control members and- adapted to be member as long as said means may be attracted slidabiy proiectedlbetween the iixed and movable by the electro-magnet. switch contacts to separate the same and elevate 40 40 6. In a device of the class described, a’pair of switch contacts, one of which is movable with reference to the other, an electromagnet in cir cuit with one of said contacts, shiitable super imposed control members oi insulation material for said movable contact, springs for urging said members in one direction, an armature in oper ative relation to the electromagnet, spring latch means connected with said armature for coupling and uncoupling said control members, and coop erating means on the movable contact and one of the control members for maintaining the same in normal position While connected by the latch. 7. In a device of the class described, a pair oi switch contacts, one of' which is movable with reference to the other, an electromagnet in cir cuit im‘th one of said contacts, shiftable control members for said movable contact, one of said members having an insulating toe adapted to be projected between said contacts, means for urg ing both of said control members in one direc tion, a spring latch carried by said member hav ing the insulating toe, a socket in the other con trol member for receiving said latch, an arma ture in operative relation to the electromagnet, and means for slidabiy connecting said latch with the armature. . 8. In a device of the class described, a pair of switch contacts, one of which is movable with reference to the other, an electromagnet in cir cuit with one oi said contacts, a pair of shiitable telescopically related control members, one of which is provided with an insulating toe adapted means for urging said control members toward the movable contact whereby the restraining means thereof will be lii’ted clear oi the shoulder of the other ot said control members, latch means for interconnecting said control members, and an armature member slidabiy interlocked with said latch means. l1. In a device oi' the class described, a sta tionary switch contact, a movable switch con tact, said movable switch contact being normally engaged with the fixed contact, an electromag net in circuit with one oi said contacts, a pair oi shiitably mounted control members, latch means ior releasably interlocking said members, means i'or urging said control members in one direc tion, insulation carried by one of said members 55 adapted to be projected between said ilxed and movable switch contacts to open the switch, a handle on one of said control members, restrain ing means on the movable switch member for engaging the control member having the handle, 60 an armature operatively related to the electro magnet and adapted to actuate said latch means upon the occurrence of an overload in the line circuit thereby to disconnect said control mem-v bers and permit the insulation toe to be projected 65 between said ?xed and movable switch contacts and to displace the restraining means of the mov able contact out oi the path oi' the control mem ber having a handle whereby manipulation oi the latter will render the control members in 70 eiIective as long as the magnet attracts the ar mature. ~ JOSEPH E. FARRELL.