US3386061A

US3386061A - Electrical connector means with automatic thermal responsive overload circuit breaker

Info

Publication number: US3386061A
Application number: US562835A
Authority: US
Inventors: Kenneth M Delafrange
Original assignee: Individual
Current assignee: Individual
Priority date: 1966-07-05
Filing date: 1966-07-05
Publication date: 1968-05-28
Anticipated expiration: 1985-05-28

Description

May 28, 1968 K. M. DELAFRANGE 3,335,061

ELECTRICAL CONNECTOR MEANS WITH AUTOMATIC THERMAL RESPONSIVE OVERLOAD CIRCUIT BREAKER Filed July 5, 1965 IN VEN TOR. leg/M5774 M' WFkflA/m,

United States Patent ELECTRICAL CONNECTOR MEANS WITH AUTO- MATIC THERMAL RESPONSIVE OVERLOAD CIR- CUIT BREAKER Kenneth M. Delafrange, 96 Washington Ave., Westwood, NJ. 07675 Filed July 5, 1966, Ser. No. 562,835 1 Claim. (Cl. 337-1) ABSTRACT OF THE DISCLOSURE An electrical connector and circuit breaker operable in connecting extension circuits from an outlet in a main circuit and in protecting against current'overloads in the circuits above a predetermined current carrying range for which the circuit breaker is designed, the structure embodying in use a normally closed thermal responsive circuit breaker for automatically opening the circuit on overload with means preventing arcing and reclosing of the circuit breaker, this means being manually operable to reset the breaker, and, when reset to open the breaker at the will of a user.

This invention relates to an electrical plug connector with automatic current overload circuit breaker. More particularly, it relates to a plural conductor circuit extension connector with contacts for conductive association with an electrical outlet and having a thermal responsive overload circuit breaker in series connection between one of said contacts and a circuit extension conductor means.

One of the objects of the invention is provision of a simplified combined electric plug in connector and circult breaker which will automatically protect against overheating the conductors of an electrical circuit extension from overloading the circuit beyond its predetermined safe current carrying capacity.

A further object of the invention is the provision of a plug connector-circuit breaker combination thermally responsive to current load conditions to open the circuit on current overload and with means to prevent arcing and reclosing of the circuit until manually reset, and, in modified form, a connector-breaker arrangement of the kind wherein the arc prevention and circuit reclosing prevention means may be also manually operable to open and close the circuit under normal load conditions.

Other objects and advantages of the invention will become apparent from the following specification and by reference to the drawings forming a part thereof, where- 1n:

FIG. 1 is a view partly broken in elevation showing conductors and conductor-circuit breaker assemblies as positioned and held between joined internally recessed body portions of the plug.

FIG. 2 is a broken cross sectional view on line 2-2 of FIG. 1 in the direction of the arrows.

FIG. 3 is a detail plan view of circuit breaker arrangemerit as in FIG. 2 but with element 12 broken away and with a modified insulator slide.

Having reference tto the drawing, the structural combination comprises an insulating body of mating half sections 1 and 2, each internally recessed to receive, position and anchor therebetween in respective receiving recesses therefor a plug contact and conductor assembly 3; a plug contact, thermal circuit-breaker and conductor assembly 4; and a dielectric arc preventing operating means 5 and its actuating spring 6.

The contact and conductor assembly 3 includes a blade contact 7 with a portion thereof within the plug body shaped in conformity to a receiving recess in the body so that opposing shoulders and side walls of the body defining the recess position the contact and prevent side or endwise movement thereof, a conductor portion 8, which may be as shown integral with the contact or otherwise and fixed thereto, not shown, pass through the plug body terminating in connection with a circuit extension conductor 10 or its equivalent as at 9, or in any other manner of good electrical connection.

The plug contact, thermal-circuit breaker and conductor assembly 4 includes a blade contact 11 also shaped, positioned and held in the body in manner described for contact 7, and has fixed thereto as by riveting 13 a bimetallic thermostatic member 12 which comprises joined strips of conductive metal or metal alloy having different coefficients of expansion. This member 12 has fixed thereto at its free end a contact 14 raised from the surface of thermostatic member. A second corresponding bimetallic member 15 carries raised contact 16 at its free end and is positioned and held at its other end between the body sections in a conforming recess so that the free ends of the bimetallic members overlap with the contacts thereon normally held in abutting conductive relationship. Member 15, at its fixed end is provided as at 17 or the like for connection with a circuit extension conductor here illustrated as wire 18.

Composite strips of conductive metal or alloys of differing coefficients of expansion, employed as thermal responsive conductor elements in electric circuit breaking operations, are not new in the art. So used, however, under substantial current carrying loads there is likelihood of drawing a substantial and damaging arc in contact separation mainly from lack of speed in such separation. Thermal responsive conductor elements 12 and 15 are designed, shaped and held in the insulating body of the plug with contacts 14 and 16 in firm conductive engagement to remain so under normal heating through a predetermined safe current consumption load range in circuit extensions from the plug. In event of overloading such circuits beyond the predetermined safe current load range for which a particular circuit breaker is designed, resultant overheating of elements 12 and 15 causes each bimetallic element and its contact to quickly swing away from each other in opposite directions. This speed of contact separation is aided and enhanced by the insulator slide operator 5 moving transversely between the contacts and insulating one from the other.

Operator 5 is provided intermediate its end portions with an aperture to provide passage therethrough of the contacts in making and breaking engagement, and to provide side portions of the slide straddling the contacts and connecting the end portions. This slide has restricted transverse movement in the plug in a guide recess formed between the plug portions. At one end portion the insulator slide has a narrowed end extension defining stop shoulders on the slide adapted to engage inner surfaces of the plug body to limit movement of the slide in one direction, the narrowed end extension, in the so stopped position of the slide, extending outward of the plug body providing a portion to be engaged by a finger to reset the slide. At its other or opposite end portion the insulator slide is centrally recessed providing side leg portions which in movement of the slide have end engagement with inner surfaces of the plug body to limit movement of the insulator slide in direction opposite to that first mentioned. Spring 6 is positioned in a recess in the plug body to bear at one end on inner surface portion of the plug body and at the other end against a transverse portion of the slide disposed between the end recess and the slide aperture. This transverse portion of the slide in normal use of the device has a point edge bearing with the raised side edges of the contacts under pressure of spring 6. The force applied to the insulator slide by spring 6 produces instantaneous projection of the slide when the contacts open on overload but is insufficient to cause opening of the contacts which are feld firmly closed by the much greater power exerted by the composite members 12 and 15 under normal heating throughout the predetermined safe current load range for which the connector is designed.

When power demands in extension circuits from the connector reach overload values, abnormal heating of composite conductors 12 and 15 results, causing the free contact carrying ends of the members to flex away from each other, thus breaking the circuit by separation of the contacts. In this operation the power of the composite conductors normally holding the contacts together is relaxed allowing the insulator slide to be projected where it becomes interposed between the contacts preventing reclosing of the contacts on cooling of composite conductors. In its projection between the contacts, the operation of the slide enhances somewhat the speed of contact separation. The insulator slide remains in the projected position preventing reclosing of the circuit until it is manually reset by an operator by inward pressure applied to the narrowed end portion of the slide to compress spring 6 and allow reengagement of the contacts.

In FIG. 3 there is shown in broken plan view a modified slide operator having at the recessed or spring loaded end of the insulator slide a finger operable projection which extends outwardly of the plug structure when the slide is in its retracted position. Added power may be applied by an operator by finger pressure on slide operating extension to move the slide in wedging action between the contacts, the portion of the insulator slide in engagement with the contacts and the edge portions of the contacts being rounded or beveled to render the separation relatively easy under application of the added manual power. So separated, the contacts remain insulated from each other by the insulator slide until the slide is reset manually by pressure applied to its opposite end to restore it to its normal operative position.

The connector body portions may be of any suitable insulating composition interiorly and accurately recessed in receiving conformity with the insulator slide, forming a guide recess therefor, and the conductive assemblies designed and contoured for positioning fit therein. These assemblies are detachably mounted by mere insertion in their respective recesses, the other body portion is then applied and the combination is then fixed together by tubular riveting in known manner or by the screw bolts 21 as shown.

Having described the invention in connection with a particular embodiment thereof, words employed are those of description rather than of limitation, and changes within the purview of the appended claim are contemplated without departure from the true scope and spirit of the invention.

I claim:

1. An electrical plug connector and overload current circuit breaker for branch circuit connections therefrom, an insulator body of mating half portions recessed interiorly and longitudinally in conformity with conductor assemblies to be anchored therein and transversely recessed to receive and hold a dielectric slide member for limited slidable movement transversely of the plug, spaced conductor assemblies conforming to the provided recesses therefore extending longitudinally thereof the body anchored therein between the body portions, said spaced conductor assemblies comprising one unit comprising a continuous conductor element having binding terminal means at one end thereof and plug contact means extending outwardly of the plug body at the other end and a second conductor assembly of two aligned structural units one having plug contact means extending outwardly of the plug at one end and connected therewith at an inner end a bimetallic strip of metals with different coeflicients of expansion having a contact mounted at the free end of the strip, the other unit comprising a bimetallic strip of metals with different coefficients of expansion having binding terminal means at one end and at a free end a contact mounted thereon overlapping said first strip free end with the contacts in abutting engagement in circuit continuity, a finger operable dielectric slide contoured and apertured at a central portion thereof for passage therethrough of the abutting contacts, said slide being mounted in the transverse recess of the insulator body having limited slide movement in the recess in the plane of abutment of the contacts on free ends of the strips and having an inner edge portion bounding the recess normally in engagement with the closed contacts, spring means maintaining the slide in such engagement under normal operating conditions but causing the slide to move in interposed contact covering position between the contacts to insulate the same and prevent arcing therebetween in event of overload, said bimetallic strips tending to close and hold closed the contacts but designed to flex in opposite directions to separate the contacts in event of current passage in excess of that for which the breaker is designed, and, reengagement of the contacts being prevented until the slide is manually operated to reset position, said slide being also operable from its reset position manually to open the breaker.

References Cited UNITED STATES PATENTS 2,567,361 9/1951 Bean 200116 X 2,669,625 2/1954 Roberts et al. 200 2,745,924 5/1956 Coates 200138 3,209,104 9/1965 Malone 200138 X 3,300,607 1/1967 Delafrange 200115.5

BERNARD A. GILHEANY, Primary Examiner.

H. A. LEWITTER, R. L. COHRS, Assistant Examiners.