US1511369A - Electric cut-out - Google Patents

Description

Oct. 14. 1924. 1,511,369

M. J. SANDIN ELECTRIC CUT-OUT Filed June 17 1920 INVENTOR j ATTORNEY WITNESSES:

i 1G circuit interru v315 currents of Patented Oct. 14, 1924.

. UNITED STATES 1,511,369 PATENT OFFICE.

HOUSE ELECTRIC & VANIA.

MANUFACTURING COMPANY, A CORPORATION F PENNSYL- ELEcTaIc CUT-OUT.

Appneon mea :une i7, mo. serial m. ssasss.

To all whom zt may concern.'

Be it known that I, MAUnrrs J. SANDIN, ya citizen of the United States, and a resident of Vilkinsburg, in the county of Allel 6 gheny and State of Pennsylvania, have invented a new and useful Improvement in Electric Cut-Outs, of which the following 1s a specification..

My invention relates to automatic electric ters or cut-outs and it has for one of its o jects to prevent the unnecessary interruption of the circuit in case the current onlytemporarily, exceeds a predetermined value.

Another object of my invention is to provide a cut-out device of the cartridge type that may be emplo ed in connection with ordinary cartridge-glee terminal clips and that shall embody a readily-renewable actuating element of suchI form and relation to the cartridge as to preclude the substitution of make-slnft devices therefor.

A further object of my invention is to provide a cut-out device, embodying a heating coil, that shall havemeans for preventing damage to the coil by overloads of excessive value or durationV and that shall embody thermal-responsive means for interrupting a circuit simultaneously at a plurality o f series-related positions.

In certain electric circuits, it is desirable to protect the motor or other devices therein against sudden excessive overload currents and, also, against relatively slight overload excessive duration. The first condition is taken care of by fuses and automatic circuit interrupters.

It is desirable .to permit relatively small overloads, such as starting currents, to travf 0 erse thecircuit for-a relatively short period of time'withont interrupting the circuit, as, otherwise, an unduenumber of interruptions mi ht occur. f

o this end, eut-'outs have been emplo ed which are responsive to temperature.y Iii a relatively light overload, not suflicient to ae-4 tuate the automatic interrupters and other protective devices, is sustained for 'any considerable time, the thermal-responsive cutout will interrupt thecircuit.

racticing my invention, I provide a retilla le-cartridge cut-out device infwhich a coaxially-aligned heating member, supporting a heating coil, projects into the carmember where they portion 9 of relatively e carborundum and carbon,

tridge from one end ferrule thereof. A renewable thermal-responsive element, comprising two annular conducting members soldered together in concentric relation, are mounted on the free end of the supporting are held by a screw member projecting from the other end ferrule of the casing. The outer conduct' member is adapted to engage contact members projecting into the cartridge from said other end ferrule. A longitudmally biased sleeve member normally rests against the outer conducting member to move the latter in the direction of the axis of the cartridge to interrupt a circuit through the cartridge in response to a predetermined temperature t ereln.

Figure 1 of the accompanying drawings is l an enlarged longitudinal sectional view of a. cut-out device embodying my invention.

Fig.y 2 is a view, taken along the-line II-:II of Fig. l.

Fig. 3 isa view, similar to Fig. 1, partially in elevation and partially in section.'

Figs.'4 and 5 are'detail views of a ther. mal-responsive element shown in Figs. 1, 2 and 3.

Fig. 6 is a detail view of a supporting and spacing member shown in lig. 1, and

F ig. 7 is a detail sectional view of a modified form of thermal-responsive element embodying my invention.

A tubular insulating casing 1, preferabl constructed of fiber, is rovided, at one en with a fixed en d ferru e tached in any preferred manner and, at its other end, with a removable ferrule 3, both 2 that maybe atof which lit inside the ends "of the casing 1 and are adapted for insertion inthe usual cartridge terminal clips (not shown).

A heating member 4, extending longitudinally in the casing 1, has a yhollow end portion 5 and a solid end portion 6 of different diameters, thus providing a shoulder 7 therebetween. The end portion 6 has a slightly tapered shoulder portion 8 and a threadedy small diameter. A

eating coil 10 embed d in suitable insulating material 11, such as a cement constituted chlefiy of carborundum or of a mixture of is disposed in the hollow endvportion 5 of the heating member 4 and has one end 12 soldered to the ferrule 2. The insulating material 11 is of suchl characteristics as to become a conductor at a predetermined temperature to form a protective shunt path around the heating coil and to thereby prevent damage to the latter when it is subjected to excessive current for a certain period of time. The characteristics of the insulating material may be varied by changing the proportion of the ingredients thereof, the proportion used being determined by the circuit conditions. The end 13 of the coil 10 extends into a recess 15 in the end portion 6 and is connected to the member 4 by a body of solder 14. The end terrule 2 and the hollow end portion 5l are provided with suitable insulating linings 16 and 16, such as asbestos and mica, re-

spectively. This provides good thermal and electrical insulation for the errule 2 and electrical insulation that is a relatively good heat Conductor for the portion 5.

A metal sleeve 17, having portions 18 and 19 of different diameters for embracing the end portion 5 of the heating member 4 and fitting against the inner walls of the casing 1, respectively, has an intermediate portion 20 provided with apertures 21 to reduce -the conduction of heat between the heating.

member 4 and the casing 1.

An insulating washer 22 covers the apertures 21 to prevent convection of heat from one side to the other of the portion 20 of the sleeve 17 and, with insulating spacing washers 23 disposed between the washer 22 and the inner end of the ferrule 2, electrically insulates the ferrule 2 from the sleeve 17.

A transverse insulating barrier member or i washer 24 embraces the end portion 6 of the heating member 4 against the shoulder 7 and extends to the inner surfaces of the casing 1. A heat-insulating collar or sleeve 25 covers the greater portion of the end 6 of the heating member 4.

A thermal-responsive element 26 comprises two conducting members 27 and 28 of substantially cup-shape, the member 27 having a central opening of slightly larger diameter than the open-end perimeterr29 of the member 28 to receive the latter. A relatively thin annular band or ring 30 of fusible material, such as solder, normally holds the members 27 and 28 together. The member 28 has a slightly sloping end portion 31 lubstantially corresponding to the shoul- The end portion 6 is so proportioned as to lprovide a predetermined'time limit in which heat is conducted fi'oi'i'-"they heating coil 10 to the element 26 and also to permit the element and other parts to be contained in a casing of substantially minimum size.

The end ferrule 3 is provided with an in- I terio'rly-projecting 4'insulating member or post 32 secured thereto by a metal sleeve 33 having 'edges 34 crimped `or bent intol relatively tight gripping engagement with the tending toward member 32. An interiorly-threaded ca member 35 for engagement with the threa ed portion 9 of the heating member 4 is provided with a sleeve portion 36 having its edges 37 also in relatively tight gripping engagement with the member 32. An insulat ing sleeve member 38 normally surrounds the members 32 and 35 and is provided with a rigidly secured annular ring4 or flange member 39 between which and the closed end of the ferrule 3 a helical compressionspring 40 is disposed.

The member 33 is provided with elongated resilient arm portions 41 disposed adjacent to the inner surface of the! ferrule 3 and eX- the interior of the casing 1 that are provided, at their inner ends, with contact portions 42 for engagement with the member .27 of the element 26and a shoulder portion 43 for engagement with the flange 39 to limit the outward travel of the sleeve 38 when the feri'ule 3 is detached from the casing 1. f

When it is desired to insert the element 26, the end ferrule 3, carrying the members 32, 33, 35 and 38 and the spring 40, is turned to unscrew the cap member 35 from the threaded portion 9 of the heating member 4. lThis presents substantially unobstructed, easy-V access to the threaded portion 9, since the latter is disposed relatively close to the end of the casing 1. When the ferrule 3 is removed', the unitary element 26, consisting of the ' members 27 and 28 and the fusible portion 30, may be readily placed in position over the threaded portion9 against the shoulder 8. The dimension ofthe element 26', along its longitudinal axis, is such as-to prevent its being reversely mounted in the casing. This dimension being greater than the length of the threaded portion 9, will prevent the mounting of the ferrule 3 if the element 26 is reversed.

In replacing the ferrule 3, the outer end of the sleeve 38 will be in advance of the contact portions 42 and seat itself concentrically about the member 28 against the transverse surface of the member 27. Furtherinward movement of the errule 3,to screw the cap member 35 in position on the threaded end portion 9, compresses the'r spring 40 and places the element 26 under stress at its soldered portion. When sufficient heat tofuse the material 30, in response to predetermined circuit conditions, traverses the heating member 4, the member 26 will be released and moved quickly, by the sleeve 38 andthe sprin 40, along the portion 6 of the heating mem er 4, to a position against the barrier member 24.

When the members 27 and 28 separate, arcs will' be drawn between the outer edge of the member 27 and the Contact portions 42 and, also, between the inner edge of the member 27 and the outer` edge of the mem- -ber 28. These arcs will be greatly lengthened as the member 27 is moved longitudinally in the casing l, and the sleeve 38 will interpose an insulating barrier, tending to prevent a sustained arc or to increase the rupturing capacity, bet-Weenthe contact portions 42 and the member 28. Further, the heating coil 10 is so helically wound and concentrically/disposed about the longitudinal axis of the casing as to set netic iield, the collapse of which, on opening the circuit, assists in quenching the arc drawn to the, member 27 when it is moved against the barrier member 24, the member 27 being thus moved into the magnetic ield of the coil 10.

W'hile a device constructed in accordance with my invention is adapted for insertion in the usual cartridge-fuse clips, it is, by its construction, substantially. proof against the employment therein of fuse Wire, or other subterfuges, of higher capacity or of different operating characteristics than those for which it is intended.

lt is to be understood that the element 26 may be of various other shapes and construction and, instead of comprising two separate members soldered together, it may consist of one piece having a weakened portion 44, as illustrated in Fig. 7. Various other changes may be effected in my device, Within the spirit and scope of my invention, as set forth in the appended claims.

I claim as my invention:

1. A cut-out device comprising a thermalresponsive element constituting a plurality h of sections of sheet material joined edge to edge and having one substantially continuous Surface and fusible means permittin a portion of the area of said surface to be isplaced relative to the remainder of the element in response to a predetermined temperature and for separating the said portion from the element.

2. A cut-out device comprising a casing, a supporting member disposed therein, a thermal-responsive element disposed on the supporting member, an end ferrule for the casing, and a member on the ferrule projecting into` the casing and having threaded engagement with the supporting member to hold said element and the ferrule in position.

3. A cut-out device comprising a cylindrical member, a heating member disposed longitudinally therein, and an annular metal spacing and supporting member between said members having cut-away portions to reduce the conduction of heat in-the spacing member.

4. A cut-out -device comprising a cylindrical member, a heating member disposed longitudinally therein, and an annular metal spacing and supporting member between said members having cut-away portions to reduce the conduction of heat in the spacup a maging member, and an insulating barrier memer covering said cut-away portions.

5. A cut-out device comprising a hollow heat-conducting member containing a heating element` a thermal-responsive conductive element mounted thereon having a portion separable therefrom and heating means disposed therein.

(i. A cut-out device comprising a casing, a supporting member disposed longitudinally therein, a transverse insulating barrier member embracing the supporting member and extending to the Walls oi" the casing, a thernial-responsive element mounted on the supporting member and projecting transversely therefron, a Contact member engaging theelement, and a sleeve biased against the element and movable longitudinally over the supporting member to a position against the barrier member to elongate an arc between the end of the supporting member and said contact member.

7. A cut-out device comprising relatively movable conducting members and a movable tubular insulating member for surrounding one of the conducting members and interposing an insulating barrier to elongate the arc between said members when the latter are actuated.

8. A cut-out device comprising an insulating casing, conducting end ferrules therefor, a heat-conducting member having a threaded end portion supported longitudinally in the casing. a heating coil connected between said ferrules, a thermal-responsive element av'ing an opening for mounting the same over said threaded end portion, .a Contact member engaging said element, a member projecting from one of said ferrules and having a threaded portion for engagement with said threaded end, and a sleeve engaging the element and adapted to move longitudinally in the casing.

9. A refillable cartridge cut-out device comprising an insulating casing, a removable end ferrule therefor, a heating member disposed longitudinally in the casing and having an end portion disposed adjacent to said ferrule, an annular thermal-responsive element having separable central and rim portions supported on said end portion, a resilient contact member connected to said ferrule for engagement with said rim portion, holdin means on said ferrule for engagement with said end portion, an insulating sleeve surroundin said holding means and biased longitudinally in the casing against said rim portion, a second ferrule at the other end of the casing, and heating means connected between said second ferrule and said heating member.

10. A cut-out device comprising a thermal-responsive element, a heating conductor therefor and means for insulating and shunting the same comprising a body of maducting means,

terial that is an insulator and a conductor under diiferent predetermined temperature conditions.

11.'A cut-out device comprising a thermal-responsive element, a heating conductor therefor and means for insulating and shunting the same comprising a body of material that is normally an insulator and that is a conductor at a predetermined relatively high temperature. l

12. A cut-out device comprising a plurality of relatively movable non-fusing co-operating conducting means for interrupting a circuit simultaneously at a plurality o series-related positions, one of the said con ductive means beingmaintained in conductive relation to the other by a fusible conductive material.

13. A cut-out device comprising a plurality of relatively movable non-fusing conand thermal-responsive fusible means for holding said conducting means vin co-operative circuit relationl and interruptin the circuit to form a plurality of series-re ated arcs when the thermal-responsive means is actuated.

14. A thermal cut-out comprising a dis-- coidal thermal-responsive element consisting of a air of separable non-fusing conductive discs joined at'their edges by fusible material and means exerting a shearing force adjacent the pointofjoinder ,for sepa rating the conductive discs when the fusible material is fused.

15. A thermal cut-out comprlsing a discoidal thermal-responsive element consisting of a central non-fusing conductive member and an annular -non-fusing member joined thereto by a fusible material, means for supporting the central member and means exerting a shearing force adjacentthe oint of jomder for separating the conductive discs when the fusible material is fused.

1.6. A thermal cut-out comprising a pairv f of tubular telescoping insulating members,

a conductor extending through the inner tubular member, a thermal-res onsive element comprising two separab e portions joined by fusible material having one portion secured to the said conductor and ada ted to be surrounded by the outer tubu ar member, a conductor mounted exteriorly of the outer tubular member and engaging the free portion of the said element, and means for relatively moving the'tubular telescopmembers for separating the. portions of the thermal-responsive' element when the fusible material is fused.

InY testimony whereof, Ihave hereunto subscribed my name 1920. i

y MAURITS J. sANDIN.

this 14th day of June,

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