US2619564A

US2619564A - Circuit breaker

Info

Publication number: US2619564A
Application number: US14467A
Authority: US
Inventors: James F Raleigh
Original assignee: Underwood Electric & Manufacturing Co In
Current assignee: Underwood Electric & Manufacturing Co In; Underwood Electric & Manufacturing Co Inc
Priority date: 1948-03-12
Filing date: 1948-03-12
Publication date: 1952-11-25
Anticipated expiration: 1969-11-25

Description

J. F. RALEIGH CIRCUIT BREAKER Nov. 25-, 1952 3 Sheets-Sheet 1 Filed March 12, 1194s INVENTOR. James/9'2 [L Clitomqg J. F. RALEIGH CIRCUIT BREAKER Nov. 25, 1952 3 ShaetsSheet 2 Filed March 12, 1948 INVENT0R.I K V FRI/629k BY W fl 3 Sheets-Sheet 3 INVENTQR. James F Hal 819/2 BY W 1 Q'iiorvzgg J F RALEIGH CIRCUIT BREAKER Nov. 25, 1952 Filed- March 12, 1948 Patented Nov. 25, 1952 CIRCUIT BREAKER.

James F. Raleigh River Forest, Ill.,. assignor to. Underwood Electric & Mfg. Co., Inc Chicago, 111., a corporation of Illinois Application March 12, 1948, Serial No. 14,467

8 Claims. 1

My invention is concerned with improvements. in bl-metallic reed circuit breakers.

An object of my invention is to. provide bimetallic reed circuit breakers whichv in many instances. are preferable to fuses for the protection of electrical circuits against overloads,

Another object of my invention is to provide bi-metallic reed circuit breakers of simple, compact and sturdy construction which are dependable and effective in operation and capable of. being manufactured with uniformity and, econ omy.

Another object of my invention is toprovide a. dependable and effective. lei-metallic. reed circuit breaker so constructed that it. is both compact and Wafer-like and capable of being mounted in space-conserving relationship with similar circuit breakers on a panel board or like support.

Another object of my invention is to provide the housing of a bi-metallic reed circuit breaker with an interiorly located reed-supporting stud that is readily adjustable with a tool applied exteriorly of the housing, or housing part with which the reed is associated, to effect adjustments of the reed and its contact relatively to a co-operating contact.

The aforementioned and other objects and features and advantages of my invention are discussed in the description to follow wherein reference is made to the accompanying drawings in .1

which:

Fig. 1 is. an elevational View of one side of a. circuit breaker embodying my invention;

Fig. 2 is a similar view of the other side thereof;

Fig. 3 is a top plan view thereof;

Fig. 4 is a bottom plan view thereof;

Fig. 5 is an elevational view of one end thereof;

Fig. 6 is an elevational view of the inner face of the reed-carrying component of the circuit breaker housingas such component appearsv be fore application thereto of the reed;

Fig. 7 is a view, similar to Fig. 6 and of the same component of the housing, as said component appears after application thereto of the reed;

Fig. 8 is an elevational view of the inner face of the stationary-contact-carrying component of the housing as such component appears after application thereto of the stationary contact;

Fig. 9 is an isolated side clevational view of the insulator component of the housing;

Fig. 10 is a sectional view which may be regarded as taken on the line |0-l0 of Fig. 1 and looking in the direction indicated by the arrows;

Fig. 11 is a sectional view which may be. re. garded as taken on theline ll--.-|l of Fig. 2 and looking in the direction indicated by the arrows;

Fig. 12 is a sectional, view which may be. regarded as taken on the line l2l,2 of. Fig. l and looking in. the direction, indicated by the arrows;

Fig. 13 is. a view largely in end elevation and partly in section illustrating, how. a multiplicity of my novel circuit breakers are adapted to be mounted with economy of space on av common. panel board;

Fig. 14 is a side elevational view depicting how a modified form of my novel circuit breaker may be mounted in the panel board clips. Commonly provided for the reception of conventional; fuses;

Fig. 15 is an end view largely in elevation and partly in section which may be regarded as taken on the line l5l5I of Fig. 14 and looking in the direction indicated by the, arrows.

Similar characters of reference refer to similar parts throughout the several views.

In the foregoing synopsis of what the drawings depict, and in the description to follow, the terms top, bottom, side, and end have been used for convenience on the theory thatmy novel circuit breaker is or is to be mounted on a horizontally disposed surface of a panel board, or other support. However, it will be understood that a surface whereon is mounted one or more of my novel circuit breakers may be vertically rather than horizontally disposed or may be disposed at any required or preferred angularity to, the vertical or the horizontal.

The thermostatic circuit breaker of my invention preferably comprises a closed housing 25. consisting of three components, namely, two desirably symmetrical metal side units and 21 and the insulator unit 28.

Each of the metal side units 26. and 2'! comprises a rectangularly dished central portion 29 having a marginal flange 30 provided with a plurality of notches 3! and a plurality of lugs 32. the notches being substantially wider than the lugs.

The marginal flange 3d of each

metal side unit

26 and 27 desirably has a widened lower portion 33 which is slit at 34 and conformed to be concavo-convex beneath such slit 34, as indicated at 35, to provide, an interiorly concave seat for u the cylindrically convex surface 36 of the partially cylindrical upper end 3'! of a desirably onepiece metal terminal. Such terminal suitably also comprises a threaded shank 38, a disc-like por. tion 39 from which shank 38 projects downwardly and from which partially cylindrical upper end 31 projects upwardly, and a lip 40 formed on the upper extremity of upper end 31. Such partially cylindrical upper end 31 is formed with a, plane surface dl which lies coplanar with the adjacent plane inner surface of the flange portion 33 when the terminal is appropriately assembled with a

metal side unit

26 or 27 as the case may be. Each of the one-piece terminals desirably is brazed to its associated side unit 28 or 21, with the terminal lip occupying the slit 34 of the side unit, with the cylindrically convex surface 36 of the terminal upper end 3'! engaging the cylindrically concave surface of the side unit flange portion 33, and with the disc-like portion 39 of the terminal disposed in immediate contiguity to the lower edge of the widened portion 33 of the side unit flange 30. see Figs. and 11.

Insulator unit 28 preferably consists of a single piece of fibre or other dielectric material having a rectangular central opening 32 and perimetrical notches 43.

As is most clearly shown in Figs. 1, 10 and 12, the dished portion 29 of housing side unit 26 is provided near one end thereof with an aperture in which is press-fitted and brazed one reduced end of a metal stud 4 3 which lies interiorly of the dished portion of the side unit 28 and is provided with a blind bore 45 opening exteriorly of the side unit 26. Such stud 44 is provided with another reduced end which extends through an aperture 46 in one end of a thermostatic reed 47 and conveniently is upset to secure such reed to the stud. To the reed 57, near the other end thereof, a suitable electrical contact 48 is riveted or otherwise secured. Reed 47 suitably isformed of commercial bi-metallic sheet or strip and desirably is processed, as hereinafter described, to accord it the optimum snap action requisite in a circuit breaker of my invention.

As is most clearly depicted in Figs. 8, 11 and 12, a second electrica1 contact 49, for cooperation with reed-carried contact 48 is suitably secured, as by riveting, to, within and near one end of the dished portion 29 of housing side unit 21.

With the contact-carrying thermostatic reed 41 assembled with housing side unit 26 as depicted in Fig. '7, and with contact 49 assembled with thermostatic side unit 21 as depicted in Fig. 8, the marginal flanges 38-36 of the two housing side units 25 and 21 are brought respectively into contact with and secured to the insulator unit 28 in such manner as to provide an effectively closed circuit breaker housing without permitting any flow of electricity from one to the other of the housing side units, except through the thermostatic reed M when the contacts 68 and 49 are in their normal or closed positions. noted that each lug 32 of each housing side unit 2% and 21 projects through a notch 33 in the insulator unit 28 without contacting the

other side unit

26 or 27, and is turned against the opposite face of the insulator unit where that face lies exposed by one of the notches 3| of the other side unit.

With the several elements of the circuit breaker thus assembled, the aperture 52 of the insulator unit 28 permits the thermostatic reed 47 carried by the housing side unit 26 normally to hold its contact 48 in engagement with the stationary contact 49 carried by the housing side unit 27.

Circuit breakers of my invention afford the very important advantage that a multiplicity of them may be mounted, with very economical use of space, upon and respectively edgewise to a common panel board, such as the one depicted at It Will be r 5B in Fig. 13, through which the threaded shanks 3838 of the circuit breaker terminals extend for cooperation with suitable nuts whereby the disclike portions 39-39 of the terminals are drawn snugly against the contiguous surface of the panel board and whereby the terminal shanks are held in electrical contact with conductors forming parts of the several circuits in and for the protection of which the circuit breakers are included. I believe I am the first to provide circuit breakers comprising thermostatic reeds which are carried and operate within wafer-like housings which are mountable edgewise to panel boards or equivalent supports whereon they are mounted.

The circuit breaker of Figs. 14 and 15 differs from that depicted in the preceding figures only with respect to the terminals with which the metal side units 26 and 2'1 of the housing are provided. Instead of being equipped with a brazedon terminal having a threaded shank, each of the metal side units 26 and 2'! of the circuit breaker of Figs. 14 and 15 is provided near one end of its lower edge with a rather long integral lug which is curvedly return-bent to form an open loop 5| which does not contact the other metal side unit. These loops 5i5l constitute terminals well suited for cooperation with panel board spring jaws such as are customarily provided to receive the cylindrical terminals of conventional fuses. At 52 in Figs. 14 and 15 is depicted a well-known type of panel board equipped with spring jaws 53'-53 of the kind to which I have alluded. It will be noted that each of the loops 5l5l has an angularly turned extremity 51A adapted to abut the opposed angularly turned extremity 53a of the contiguous spring jaw 53. The cooperation of the spring jaw extremities 53a-53a and the terminal loop extremities 5lA-5 i A effectively prevents the housing 25 from rocking in the spring jaws 53-53 to contact the housing of an adjacent circuit breaker.

As shown in Fig. 7, the thermostatic reed 41 preferably is processed so as to be provided with a plurality of dimples 56. The dimples accord the reed optimum snap action when heated to a predetermined temperature as the consequence of an electrical overload, caused by a short or otherwise, of the circuit protected by the circuit breaker.

After the reed has been processed as just described, the contact to be carried with it is applied and the reed is assembled with the circuit breaker side unit 26, by being mounted upon the stud 54 thereof as hereinbefore explained.

Usually, at least once, after one of my 'novel circuit breakers has been completely assembled it is tested for its ability effectively to open a circuit which it controls when that circuit carries a predetermined overload for a significant or predetermined time interval. When such testing indicates, as it frequently does, that some adjustment of the circuit breaker is necessary or desirable, that adjustment almost invariably can be satisfactorily effected by inserting an adjustment tool, indicated in Fig. 12, in the blind bore 45 of the reed mounting stud 14 and then smoothly but flrmly inclining the stud axis more or less in the medial horizontal plane of the housing 25, to vary the pressure with which the reed-carriedcontact 48 normally engages the stationary contact 49. Moreover, such blind bore 4510f the stud 44 frequently is useful in effecting adjustments made before the several parts of the circuit breaker are completely assembled;

When one of my novel circuit breakers is in service, its thermostatic reed 47 snaps the movable contact 48 out of engagement with and substantially away from the stationary contact 49 when the reed becomes heated in consequence of a circuit protected by the circuit breaker carrying a certain predetermined overload, or greater overload, for a significant time interval. Unless conventional or other, suitable means (not shown) are provided for preventing re-engagement of the contacts, the reed later snaps the movable contact 48 back into engagement with the stationary contact 49 pursuant to cooling of the reed. Whether the contacts are again more or less promptly separated by the reed 41 then depends upon whether the short or other cause of the overloaded condition of the protected circuit has been eliminated or substantially alleviated.

While I prefer that the reed 4'! be heated as the result. of its own resistance to current flowing through it from one to the other of the circuit breaker terminals, I realize, as will all skilled in the art to which my invention relates, that the heat whereto the thermostatic reed responds may be created in a contiguous conductor through which current flows from one to the other of the circuit breaker terminals.

My hereinbefore described circuit breakers, which can be very economically manufactured, are. of sturdy construction, satisfactorily closed against the intrusion of ambient dust and moisture, and are dependable and effective in operation. Moreover, unlike fuses, they do not terminate their own usefulness when they have functioned to open circuits protected thereby. In busand' airplane and other automotive vehicle services, in which my new circuit breakers presently are being extensively used, their ability indefinitely to open and close an overloaded essential circuit oftentimes is of great practical advantage, because permitting the vehicle to reach its destination or a service station as would not be feasible if the overloaded essential circuit were fuse-protected.

Having thus illustrated and described my invention in presently preferred and commercially practical embodiments thereof, what I claim as new and desire to secure by Letters Patent of the United States is:

1. In a thermostatic circuit breaker, a housing core in the form of a flat continuous rim of dielectric material circumscribing an opening of substantially the same size and shape as the dished central portions of the hereinafter mentioned housing sides, a pair of symmetrical housing sides each in the form of a sheet metal member that is centrally dished away from said housing core and has a flat perimetrical flange between which and the corresponding flange of the other housing side the housing core is disposed and clamped, a thermostatic reed disposed within the housing and supported by and electrically connected wtih one of the housing sides, a stationary contact within the housing and supported by and electrically connected with the other of the housing sides, and spaced-apart lugs projecting from each of the aforesaid flanges of the housing sides and extending over adjacent edge portions of the housing core, each said lug bearing against that face of the housing core which lies away from the flange from whence the lug projects, the free end of each said lug of each of said flanges occupying a cove recess in but not contacting the other of said flanges.

Y 2. A thermostatic circuit breaker according to claim 1. wherein the housing core is provided with a perimetrical notch snugly receiving each of the lugs of the flanges of the housing sides.

3. In a thermostatic circuit breaker, a substantially closed housing comprising. a metal side wall portion, a stationary contact within the housing, a movable contact within the housing, a thermostatic reed also within the housing and carrying said movable contact at one of its ends, and an adjustable mounting, for the other end of said reed, which lies for the most part within said housing, said adjustable mounting consisting of a metal stud having two reduced ends, one of said reduced ends being received by and retained in an aperture afforded by the reed, the other of said reduced ends being received by and extending through and secured in an aperture afforded by the aforesaid metal side wall portion of the housing and presenting an axial bore of substan tial depth opening exteriorly of the housing and having a blind end located intermediate the reduced ends of said stud.

4. In a thermostatic circuit breaker, a substantially closed housing comprising a metal side wall portion, a stationary contact within the housing, a movable contact within the housing, a thermo static reed also within the housing and carrying said movable contact at one of its ends, and an adjustable mounting for the other end of said reed, said mounting lying largely within the nousing and not extending exteriorly thereof, said mounting consisting of a metal stud having one end thereof secured to said reed and its other end reduced and received by and extending through and brazed in an aperture afforded by the aforesaid metal side Wall portion of the housing, said last mentioned end of the stud presenting an axial blind bore of substantial depth opening exteriorly of the housing.

5. In a thermostatic circuit breaker, a housing core in the form of a flat continuous rim of dielectric material circumscribing an opening of substantially the same size and shape as the dished central portions of the hereinafter mentioned housing sides, a, pair of symmetrical housing sides each in the form of a sheet metal member that is centrally dished away from said housing core and has a flat perimetrical flange between which and the corresponding flange of the other housing side the housing core is disposed and clamped, a thermostatic reed disposed within the housing and supported by and electrically connected with one of the housing sides, a stationary contact within the housing and supported by and electrically connected with the other of the housing sides, devices for retaining the housing core clamped between the flat perimetrical flanges of the housing sides without electrically connecting said sides, each of said perimetrical flanges being provided with a concavo-convex portion affording a cylindrically concave seat that is presented toward the housing core and extends crosswise of the flange to the perimetrical edge thereof, and a pair of elongated metal terminal members each presenting at one end thereof a cylindrically convex surface and a plane surface, the aforesaid cylindrically convex surface of each terminal member being disposed and secured in one of the aforesaid cylindrically concave surfaces, and the aforesaid plane surface of each terminal member being flush with that face of its associated flange that is presented to the housing core.

6. In a thermostatic circuit breaker, a housing core in the form of a flat continuous rim of dielectric material circumscribing an opening of substantially the same size and shape as the dished central portions of the hereinafter mentioned housing sides, a pair of symmetrical housing sides each in the form of a sheet metal member that is centrally dished away from said housing core and has a flat perimetrical flange between which and the corresponding flange of the other housing side the housing core is disposed and clamped, a thermostatic reed disposed Within the housing and supported by and electrically connected with one of the housing sides, a stationary contact within the housing and supported by and electrically connected with the other of the housing sides, devices for retaining the housing core clamped between the fiat perimetrical flanges of the housing sides without electrically connecting said sides, and a terminal carried by the perimetrical flange of each of the housing sides, each said terminal being a lug that is integral with its associated flange and extends laterally therefrom and is curvedly rebent for cooperation with fuse-engageable spring clips presented by a panel board or the like.

7. A thermostatic circuit breaker according to claim 6 wherein each of the curvedly rebent terminal lugs is provided with an angularly turned extremity for cooperation with a spring clip extremity to prevent turning of the terminals in tween the margins of the metallic members to 3 maintain their spacing and. to form therewith a housing. a. thermostatic element positioned within 8 the ring and between the members in generally parallel spaced relation to the latter, means electrically connecting to and supporting the element on one metallic member, and a contact carried by the other metallic member for engagement with the element, the supporting means for the thermostatic element comprising a, metallic stud having one end connected to the element and the other end connected at a recess in the said one member and provided with a blind axial bore of substantial depth opening exteriorly of the said one member.

JAMES F. RALEIGH.

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

UNITED STATES PATENTS Number Name Date 180,748 Bray Aug. 8, 1876 653,798 Fox July 17, 1900 928,947 Dawson July 27, 1919 1,639,708 Spencer Aug. 23, 1927 1,825,811 Nelson Oct. 6, 1931 1,830,657 Herbster Nov. 3, 1931 1,942,697 Henning Jan. 9, 1934 1,972,975 Brady Sept. 11, 1934 2,222,291 Freeman et a1 Nov. 19, 1940 2,289,131 Layton July 7, 1942 2,419,072 Hall Apr. 15, 1947 2,442,104 Twombly May 25, 1948 2,474,190 Porter June 21, 1949 FOREIGN PATENTS Number Country Date 295,982 Germany Dec. 30, 1916