US570419A - Alexander jay wurts - Google Patents

Description

(No Model.) 2 SheetsSheet -1.

A. J. WURTS.

CIRCUIT BREAKER.

N9. 570,419. Patented 0013.27, 1896.

WITNESSES:

ATTORNEY.

2 Sheets-Sheet 2.

Patented Oct. 27, 1896.

PEYZHS co, wom uwo WASHINGTON, n, c

A. J. WUR'I'S.

CIRCUIT BREAKER.

(No Model.)

ZWM/ UNITED STATES PATENT OFFICE.

ALEXANDER JAY lVURTS, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO THE WVESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, OF

SAME PLACE.

CIRCUIT-BREAKER.

SPECIFICATIONforming part of Letters Patent No. 570,419, dated October 27, 1896.

Application filed May 29, 1896. Serial No. 593,623. (No model.)

To all whom it may concern.-

Be it known that LALEXANDER JAY \VUR'rs, a citizen of the United States,residin g in Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented anew and useful Improvement in Circuit-Breakers, (Case No. 703,) of which the following is a specification.

My invention relates to circuit-brez'tkers, and has particular reference to circuit-breakers which are employed in connection with high-potential circuits carrying currents of considerable volume, it being specially designed for use in stations supplying current to electric-railway circuits, although not limited to that specific use.

One of the objects of my invention is to provide a circuit-breaker which may be readily closed by the application of a comparatively slight force, so as to make a perfect contact between its engaging terminals, and which will open automatically and without frictional resistance whenever the current in the circuit increases materially beyond a predetermii'ied maximum limit.

A further object of my invention is to provide an improved means whereby any material increase of current beyond the predetermined limit will serve to suddenly release the movable member of the breaker, whether the increase of current to or through the critical maximum amount be gradual or sudden.

A further object of my invention is to provide a breaker which may be opened under any amount of load without any injury to the main contactterminals by reason of the formation of arcs between the same.

A further object of my invention is to provide a breaker in which the are formed by the separation of the shunt-contacts shall be horizontal, and therefore easily interrupted, and which shall be above the main portion of the apparatus, where it will be least likely to have any injurious effect.

Referring to the drawings, Figure 1 is a view, partially in section and partially in side elevation, of my circuit-breaker in closed position. Fig. 2 is a similar view showing the circuit-breaker partially closed, certain parts being broken away. Fig. 3 is a detail perspeetive view of the movable shunt-contactsupporting plate. Fig. i is a front elevation. of the circuit-breaker in open position. Fig. 5 is a detail sectional view, the section being on line a of Fig.4; and Fig. (i is a detail view, upon a smaller scale, of the stationary shunt contact-terminals, looking downward from the rear of the switchboard.

Reference being now had to the drawings in detail, 1 is the base or switchboard panel upon which the operative parts of the switch are mounted, and which may be constructed of marble or other suitable insulatingmaterial.

is a hollow block or casting, which is provided with the usual lcaf-s iring jaws 3, for the reception of the arm l of the movable member of the circuit-breaker when it is thrown open. The arm 4: is journaled at its inner end upon a pintle 5, mounted and free to turn in the casting 2. A stop-piece 6, having a lug (3, is mounted upon the pintle 5 and rigidly fastened to it by a set-screw 7. A block 8 is pivoted to the piece (3 and bears against the upper end of a coiled spring 0. A red 10 depends from the block 8 and serves to retain the spring 9 in its proper position. The arm at is provided with the usual handle 11 and also with a small roller 12, the latter being in position to be engaged by the hook at the end of latch 13 when the breaker is closed. The contact portion of the movable member of the breaker is a bar or plate 14-, to which are fastened, preferably at its upper edge, two curved contact-springs 15, the pur-.

pose of which will be hereinafter more fully described.

Suitably fastened to the bar or plate ll, and preferably between the same and the ad jacent portion of the arm a, is a spring-plate 16, preferably formed of copper, and having two curved end portions projecting beyond the bar 1%. Fastened to each projecting end of this spring-plate is an auxiliary contact-piece 17, comprising a block 18, formed of carbon or some other good conducting material, which is practically infusible, and a plate 19, of copper or other metal having a high degree of conductivity. I prefer to form the blocks 18 of carbon, but I do not desire to limit my invention to this material, for the reason that graphite or some other composition which has the necessary conducting properties and is practically int'usible by electric arcs may be employed in lieu thereof. Each metal. plate 19 is set into a recess which is formed in the outer face of the block 18 and extends through a portion only of its length, so that the outer face of the plate and that of the tree en d of the block combine to form a single smooth contactsurface. The contacts 17 being connected by a single copper plate, a good conducting-path between them is insured irrespective of the character of the contact between the said plate and the bar it.

The ends of the su 'iporting-spring '16 are preferably clamped between the blocks 18 and plates 1.), so as to make good electrical contact with the said parts. I

I prefer to give the faces of the contactpieces 17 the form of the arc of a circle struck from the center of the pintle 5 when the circuit-breaker is closed. These contacts are also slotted longitudinally, as clearly indicated in nig. 1-, such slots extending a short distance into the supporting spring-plate, in order that the contacts may adapt themselves to any irregularities in the surface of the stationary contact-terminals with which they engage.

Each of the main stationary contact-terminals 20 consists of a bundle of thin plates which are clamped together and to a projectionon a supporting base-piece 21. The inner end of each contact-terminal is also prefer ably united to the part 21 by solder or amalgam. These laminae, or the larger portion of them, terminate in a plane which is inclined at such an angle to the base of the circuitln-eaker that the contact bar or plate 17L will make a close contact therewith. The angle of the plane of the contact ends of these laminze is also such that the bar or plate l-i will. engage them one after another, beginning with the outermost one, in closing the breaker, thus successively lil 'ting or deflecting each of the said ends slightly from its normal position.

As will. be seen by reference to Figs. 1 and ol' the drawings, this operation results in a maximum deflection of the free ends of the outer laminae and in little or no deflection ot' the innermost ones. A sliding engagementbetween the parts ll and 20 is also elt'ected, which helps to insure a good contact between them and keeps the contact surfaces bright and. clean. While I prefer to form these contacts of thin copper plates, it will be understood that the individual elements of which the contact composed may have any other [Form in moss-section which may be found convenient, provided they are sul'iiciently resilient to efli'ect the desired result.

Suitably fastened, preferably by means of bolts,to a projection on each. supportinginece 21 is a swing-plate 22, to the outer end of which is fastened a terminal contact 23, with which the corresponding movable contact 17 engages. Each of these contacts 23 comprises a block it and a plate 25, which are preterably made of the same materials as are the correspomling blocks 18 and plates 19 of the contacts hereinbefore described. The curvature of the contact-faces of the contacts 23 is also the same as that of the faces of contacts 17, except that it is concave instead of convex. This curvature of the engaging faces of the shunt-contacts insures a good electrical contact between the entire engaging surfaces, not only when. the breaker is closed, but during the opening of the same, until the metal portions of the contacts are separated.

The construction of the Sllllllll-(fOlllllCl'S partially of metal and partially ol carbon, or some other substantially int'usible conducting materiz'rl, is an important improvement over the carbon slu'uit-contacts which have heretofore been employed in. this class of devices.

In the employment of shunt-contacts made entirely of carbon in circnit-breakers employed to open circuits carrying heavy eurrcnts it has been found that the carbon was not a su'lliciently good conductor to shunt all of the current around the main cii.cuitterminals, and that consequently su ch main circuitterminals often became seriously injured by the arcs, due to the nnshunted current, so much so, in fact, that it was necessary to cut away the blistcred surfaces before the switch could be again closed. \Vith the present construction of shunt-contacts it will be readily seen that a complete metal path is provided. for the current until the main contacts have become separated a considerable distance, and that consequently the entire current will be shunted. The conductibility of the shuntpath for the current is also materially improved in the form of circuit-breaker shown by curving the metal contact-faces in. the manner above described. \Vhen the metal con tact-plates of the shunt become separal ed, the current will obviously be compelled to take the path provided. by the in'l'usible material, so that the final interruption will occur, as in. the old form of breaker, where the resulting arc can do little, it any, damage. These stationary shunt contact-blocks also have their free ends beveled or inclined toward. each other, as indicated. most clearly in Fig. (3, in. order that the interruption of the current shall occurattheiroutermostpoints. lhisl'caturc of construction is desirable in order that the contacts may be placed near enough together to make a compact structure without danger of arcing across from one terminalto the other.

he location of the stationary shunt-contacts side by side above the main body of the breaker is desirable, since the arcs formed between the separated terminals are substantially horizontal, and therefore easily interrupted, and, furth ermore,all danger of injury to the main terminals is substantially avoided by reason of such location. Any tendency to arcing between. the stationary contacts is IIO largely counteracted by the repelling action excited by the arcs against each other.

Instead of employing a solenoid or magnet coil for actuating an armature to release the movable member of the circuit-breaker when the current increases beyond the predetermined limit, as is usual in this class of devices, I utilize one of the main contacts of the circuitbreaker for this purpose, and in lieu of the usual solenoid or magnet core I provide a body of magnetizable metal, preferably in the form of a band 26, which partially surrounds the stationary contact, and is of sufficient width and thickness to provide a good magnetic circuit. As shown in Fig. 4 ofthe drawings, this band 26 is fastened in position by means of the bolts which fasten the contact to the base-piece 21, and is bent around the edges of the contact in such manner that the end near the central line of the breaker projects somewhat beyond the face of the contact and at right angles to the plane of its back, the other end projecting a materially less distance. This particular form of band is not essential, but it has been found operative and useful in practice.

Below the stationary contacts and substan tially midway between them is located a block or casting 27, provided at one side with an arm 28, between which and the base of the casting is pivoted a bar-armature 29. This armature 20 is provided with an opening 30 midway between the stationary contacts, through which extends a bolt 31, the head of which rests upon the upper surface of the armature. The bolt 31 also extends through a similar opening in the latch 13, and is provided with a nut, so that when the armature is actuated by the magnet above described the first part of its movement will serve to raise the bolt until the nut is brought into engagement with the latch 13, and a further movement will serve to withdraw the latch from the roller 12, thus permitting the movable member of the breaker to be instantly thrown back by the action of the spring 9. The lost motion between the armature and latch is employed in order to permit the armature to enter the strongest part of the magnetic field before acting upon the latch, thereby insuring an effective and sudden releasing blow.

In order to insure the retention of the movable member of the breaker in its closed posit-ion until the volume of current at which it is designed to open is reached, and to insure a sudden tilting of the armature and consequent withdrawal of the latch when the current reaches the maximum allowable limit, I provide the second -stationary member 20 of the breaker with an iron band 26, preferably of the same shape as'the band 26, except that the portions adjacent to the edges of the contact are materially shorter than the corresponding portions of the band 26, in order that the number of lines of force passing through the adjacent end of the armature shall be less than the number threading the opposite end.

The necessity of some expedientwhereby the pull of this magnet shall be made weaker than that of the other is obvious, since the magnetic pull at this end constitutes a load which must be overcome in order to eifect the withdrawal of the latch; but it will be understood that means different from that shown, whereby the strength of the magnet or the action of the same upon the armature is modified, maybe employed, if desired. The character of the load is such that when the pull upon the opposite end of the armature is sufficient to overcome it the tripping action will occur with a sharp, sudden jerk, which is particularly effective and desirable in this class of apparatus. I also provide the load end of the armature with a small set-screw 32, the inner end of which bears against the outer end of the band 26, and is adjustable in order to provide for diiferent loads. I prefer to make this screw of magnetizable metal in order that it may serve as a saturated element in the magnetic circuit; but it may be made of other material, if desired. Any other suitable adjustable device may also be employed in lieu of the screw.

83 is a bar or rod provided with a suitable scale and supported from the armature and parallel to it by means of rods A weight 35 is mounted upon the bar 33 in such manner that it may be moved back and forth thereon in accordance with the critical load for which the breaker is to be set.

36 is a screw for clamping the weight at any desired position on the bar 37 and 38 are bars or strips provided with outwardly-proj ecting upper ends and with handles at theirlowerends. These bars have a slot-and-pin connection with the base 1 and serve, respectively, when pressed upwardly to tilt the armature in the one direction or the other.

It will be understood from the foregoing description that the breaker may be set by means of the screw 32 and weight 35 to open upon any desired load, and that when such load is reached the latch will be withdrawn with a sudden jerk due to the sudden release of the armature by the load-magnet and the lost motion between the latch and armature. The spring 9 will then act through the parts 8, 6, and (5 to separate the contacts, after which the arm i will fall away from the lug 6 and between the leaf-springs ,3, by reason of the impetus imparted by the spring 9 and the action of gravity.

Immediately upon the separation of the main contacts, which will occur without material frictional resistance, the entire current will be shunted through the copper plates 19 and 25 and the spring- supports 16 and 22. \Vhen the plates 10 and 25 become completely separated, the current will be forced to take the path through the infusible blocks 18 and 2t and will be finally interrupted at the outermost corners or tips of these blocks. It is therefore apparent that under ordinary cireumstances all. possibility of injury to the main contacts of the breaker is obviated. Should it happen, however, that the current should not be entirely shunted through the auxiliary contacts, any current which fails to take that path will be interrupted between the springs 15 and the outer sides of the ends of the stationary contacts, where it will do little, it any, harm.

I claim as my invention 1. In a circuit-breaker or switch, the combination with main contact-terminals of a shunt around the same provided with separable contacts each of which has a metal portion and an intusible conducting portion so arranged that the current will be first shunted through the metal and then through the infusible portions.

2. In a circuit-breaker, the combination with a pair of stationary main circuit metal contacts and a bridging movable contact, of a pair of auxiliary stationary contacts and a pair of electrically-connected cont-acts cooperatin g therewith to form a shunt around the main contacts, said auxiliary contacts having metal portions which are in engagement when the switch is closed and which do not move out of engagement until the main terminals have become separated, also having infusible conducting portions, which engage with each other after the metal portions become sepa rated, and the separation of which interrupts the current.

3. In a circuit-breaker or switch, the combination with stationary and movable maincircuit contact-terminals, of a pair of springsupported contact devices electrically c011- nected with the stationary main circuit-terminals and a movable pair of spring-supported contact devices electrically connected together and supported by the movable main circuit-terminal,both sets of spring-supported contacts having metal engaging portions and carbon engaging portions, the separation of said carbon portions serving to interrupt the current.

i. In a switch or circuit-breaker, the combination with a pair ol stationary main-circuit contact-terminals, of a movable maincircuit contact-terminal bridging said stationary contact-terminals and provided with detachable pieces for making final contact therewith, and a shunt around said main-circuit contact-terminals provided with separable contacts the engaging portions of which are partially of metal and partially of infusible conducting material.

5. In a switch or circuit-breaker, the combination with a pair of stationary main-circuit contact-terminals, of a movable main-circuit contact-terminal bridging said stationary contact-terminals and provided with detachable contact springs ifor making final contact therewith, and a shunt around said main circuit-terminals provided with separable contacts the engaging portions of which are parti ally of metal and partially of carbon.

t3. In an. automatically-opening switch or circuit-breaker, the combination with separable main circuit-contacts, of combined metal and carbon contacts provided. with spring-supports and located in a shunt around the main circuit-contacts, means for releasing the movable contacts and means for separating the same from the stationary contacts.

'7. A circuit-breaker having a pair of main stationary contacts and a single bridging movable Contact, in combination with a pair of stationary shunt-contacts and a pair ot cooperating movable contacts connected by a single spring-plate conductor.

8. In an automatic circuit-breather,the combination with apair of stationary contacts, an iron band partially surrounding each of them, a bridging movable contact and alatch therefor, of a pivoted armature having an adjust-- able projection at one end normally bearing against the adjacent iron band, and a longitudinally-adj ustable weight on the other end.

9. In an automatic circnit-breaker the combination with the separable contacts and a locking device therefor, ot a releasing-armature, and a body of magnetizable metal adjacent to said armature and partially surroumliug one of the circuit-terminals.

10. 111 an automatic circuit-breaker the combination with the separable contacts, a latch and means for separating the contacts when the latch is withdrawn, ot' a pivoted armatu re having a lost-motion connection with said latch and a body of magnctizable metal partially surrounding one of the circuit-terminals and having an air-gap adjacent to said armature.

1.1. In an automatic circuit-breaker, the combination with a pair of stationary contacts and iron bands partially surroumling the same, of a movable bridging contact, means for locking the same in closed position, a pi voted releasing-armature and an adjusting means interposed between one end of the same and the adjacent iron band.

12. In an automatic circuit-ln'ealcer, the combination with a pair of stationary contacts, a movable contact bridging the same, a latch, and means for separating said contacts upon the withdrawal of the latch, 01; a latch-with drawing armature, bodies of magnetizz'tblc metal partially surrounding the respective stationary contacts and acting upon the armature in opposition to each other, said parts being so constructed and arranged that the pull exerted by one magnet may be overcome by that of the other, when the current in the circuit exceeds a predetermined limit.

I}. A circuit-breaker having separable main contacts and auxiliary shunt-contacts located side by side above the main contacts, the outer ends of the stationary members of said shunt-contacts being beveled or inclined inward toward each other, whereby the circuit will be finally interrupted at the outer corners of said contacts.

14:, In a circuit-breaker, the combination with the main stationary and movable contacts, of a pair of stationary shuntcontacts, and cooperating contacts carried by and movable with the corresponding main contact member, the engaging faces of said shunt-eontacts having a curvature of substantially the arc of a circle struck from the pivotal support of the movable member as a center.

15. In a switch or circuit-breaker, a solid movable contact-terminal in combination with a cooperating stationary terminal con sisting of a bundle of conductors the contact ends of which are in a plane which is inclined with reference to the position of the individual conductors and which are engaged by the contact-face of the movable terminal. in succession beginningwith the outermost ones'in closing the breaker,whereby said ends are successively deflected slightly from their normal positions and a lateral pressure is exerted against them.

16. In an automatic circuit-breaker, the combination with a pair of stationary contacts each consisting of a bundle of conductors the contact ends of which lie in a plane inclined with reference to-the position of the in dividual conductors, of a solid bridging contact bar or plate movable into and out of contact with said contact ends, the engagement being made successively with said ends, beginning with the outermost ones, whereby they are successively deflected from their normal positions, means for locking said movable contact in its closed position and means actuated by an excessive current in the circuit to unlock said movable contact.

17. In an automatic circuit-breaker, the combination with a movable contact bar or plate, and a pair of laminated stationary contacts, substantiallyperpendicular to the supporting-base and having inclined contactfaces along which the movable contact-bar has a limited sliding movement,whereby the ends of the laminze are successively deflected from their normal positions, of means for locking said contacts in engagement and means actuated by an excessive current for unlocking the same.

In testimony whereof I have hereunto subscribed my name this 26th day of May, A. I). 1896.

ALEXANDER JAY VVURTS.

Witnesses:

TESLEY G. CARR, IIUBERT O. TENER.

Images