US2275795A - Electrical thermomotive device - Google Patents

Description

March 10, 1942. c; w. MUSSER 2,275,795

ELECTRICAL THERMO-MOTIVE DEVICE Filed March 6, 1941 Ennentor Witness I p attorney Patented Mar. 10, 1942 UNITED STATES PATENT OFFICE} 2,275,795 ELECTRICAL THERMOMOTIVE DEVICE Charles W. Musaer, Omaha, Ncbn, aaaignor to Jubilee Manufacturing 00;, Omaha, Nebn, a corporation of Nebraska Application March 6, 1941, Serial No. 381,969 8 Claims. (Cl. 200-138) The present invention relates to the electrical art and more particularly to electrical circuit breakers and has for an object to provide a breaker which may be manually or otherwise closed in accordance with the particular en-- vlronment in conjunction with which the device is used and which is so constructed that it may be repeatedly used.

Another object of the invention is to provide a thermo-motive device for said purpose of economical manufacture which is of permanent, durable character.

A still further object of the invention is to provide a circuit breaker, the circuit opening action of which is comparatively very rapid. t Other and further objects and advantages of the invention will be obvious to those skilled in the art from the following detailed description thereof.

In the drawing:

Figure l is a side elevation of the new device mounted on a fragment of a block of insulation, certain movable'electrodes employed being in a closed contacting position with respect to each other.

Figure 2 is a similar view certain portions of the new device being in section, said electrodes being in an open position. I

Figure 3 is a top plan view of the invention and showing the latter included in a diagrammatically illustrated, energized electrical circuit together with an incandescent light bulb.

As heretofore practiced in the art, especially in dwelling houses meltable fuses have been commonly employed in electrical circuits for breaking the later at times when short circuits have occurred, said fuses requiring replacement often by people unfamiliar with the electrical art thereby causing delay, danger and injury to saidpersons, the latter also often inserting new fuses repeatedly in damaged or improper circuits without repair of the latter, thereby wasting said fuses unduly, and the present invention aims to obviate said undesirable features of the prior practice.

Referring now to the drawing for a more particular description ll indicates a fragment of a block of insulating material which is preferably stationary such as when attached to thewall of a switch box within a dwelling house or when attached to the dashboard or other suitable portion of an automobile or the like having electrical instrumentalities for which protection against abnormal electrical currents is desired.

The new device includes a thermo-motive electrode generally indicated at H and which preferably consists of a bi-metallic disk of concavoconvex contour incross section, the half portion I! of which is formed of one selected metal and the other oppositely disposed half portion i3 thereof consisting of a different metal, said electrode portions i2 and I3 being suitably Joined together in a manner whereby the disk is sufliciently thin to be flexible for later described purposes and sufliclently thick to resist a selected degree 01' heat applied to said disk.

The disk H as thus described is normally of an initial form-sustaining character and while a bi-metallic disk is preferred it will be understood that any electrode formed of one or two pieces of metal which will become suitably deformed for later described purposes, upon becoming heated sufliciently, may be employed in lieu of said preferred bi-metallic construction.

As .best shown in Figure 2, preferably the medial portion of the disk is secured by means of a bolt or screw electrode H to said insulation it, a nut or the like it preferably being disposed between said block and said disk. 4

An electrode it having an inwardly oil-set detent portion or hook i1 is disposed in electrical contact with said disk and secured to the latter by means of. a rivet i8 preferably adjacent the perimeter of said disk and it will be understood that said disk, for certain uses, may be elongated in lieu of the circular disk specifically i1 lustrated.

The detent ll is provided with an outwardly flared guide portion i8 for facilitating engagement of a later described arm under and with said hook,

An electrode 28 having an arm portion ii is carried by the disk and electrically insulated from the latter by means of laminations of insulating material or washers 22 and 23, said member 20 being mechanically secured to the disk by means of a rivet or the like 24 which also secures said washers together.

The electrode "is preferably formed integral with the arm 2i and of resilient material such as spring bronze whereby resultant from said electrode l6 away from the rivet 24 for permitting said free end of the arm to engage under the hook detent II; whereupon said free end of the electrode [6 returns to a normal position, as shown in Figure 1, said electrodes 20 and I6 then being disposed in electrical contact with each other.

It will be understood that the above described device may be enclosed, if desired, in a housing or suitable container, in which case the latter is preferably provided with a glass or transparent mica window whereby an operator may visualize the position of the electrode portions l1 and 26 with respect to each other for noting whether or not they are in contact and at times when a housing is employed a knob of insulation or plunger is disposed through a wall of said housing whereby the operator may place his finger upon said plunger for causing said free end 26 to engage with the detent hook il. As specifically shown in Figure 2, said knob of insulation 21 is carried by the arm 2! and secured to the latter by means of a screw 28 whereby the operator may readily depress the arm 2! by placing his finger or the like on said knob for said purpose and without said finger becoming electrifled.

An electrode clip 29 is secured to the rivet 24 for facilitating an electrical connection between a wire 30, said clip and the metallic rivet 2|, said wire preferably being soldered to the clip as at 3 i.

Similarly a wire 32, as shown in Figure 1, is soldered as at 33 to a second clip'electrode 34, an end of the latter being mechanically and electrically attached to the screw electrode H by a suitable means such as the nut 35.

As thus described at times when the wires 30 and 32 are included in a closed electrical circuit the current will pass from a source of energy through the screw electrode H to the medial portion of the disk ii and through the electrode i8, arm 2|, rivet electrode 24 and clip 29 at times when the wire 32 is in electrical communication, as described, with the medial portion of the disk. It will be further noted that for certain types of use the wire 32 may be electrically connected to the disk adjacent the perimeter thereof although the disk becomes heated and more quickly responsive, as later described, at times when the wire 32 is electrically connected to the medial portions of said disk.

For certain uses the new device is comparatively minute with respect to the proportional size thereof specifically illustrated imthe drawing, and it will be understood that the device is so constructed and assembled that the disk becomes deformed resultant from a current passing through the disk which is greater than a preselected normal degree resultant from said disk becoming heated as later described. Manufacture of specimens of the new device are made of a preselected capacity to be used in conjunction with and for a certain current. During manufacture the devices are marked "15 A", "30 A", 60 A and the like for denoting that the devices so marked are of respectively 15,

30 and 60 ampere capacity. For automobile use or when the source of electrical energy is a conventional 6 volt battery, said specimens are correspondingly and approximately marked for purposes well known to those skilled in the electrical art.

The capacity of any specimen of the new device to open a circuit at times when the latter includes more amperage than desired is governed by the particular construction of a specimen, either by making the disk ll thicker or thinner. by the degree of convexity of said disk or the lack of said convexity or by the degree oi the urge provided by the spring portion 25 or by the length of the arm 2| with respect tothe hookdetent l1.

Referring to Figure 3 the wire 30 is in communication with the wire 36 the latter also being in electrical communication with a utilitarian electrical instrumentality such as the incandescent'light bulb generally and diagrammatically indicated at 31, said device 31 being in communication with a battery 38 or other suitable source of electrical energy through a wire 39, said battery being similarly connected to the wire 22 througha wire or similar conductor 40 and as thus described it will be understood that the new invention may be included in the described electrical circuit for protecting the electrical instrumentality 31 from damage at times when and if the current generated becomes too great for the capacity of the device 31 and greater than the disk H will carry without deformation.

In operation, assuming that the disk H is mounted to a stationary object, at times when electrical current flows through said disk, the latter becomes correspondingly heated, and assuming that the disk has been constructed to withstand a current of i5 amperes said circuit operates normally, At any time the amperage of said circuit becomes increased, by any means, above said selected normal degree, said disk instantly becomes correspondingly heated proportionally and to a greater degree than its capacity to withstand said heat without deformation, thereby causing the perimeter of the disk to be moved in the direction of the arrow 4| and towards the convexed medial portion of the disk, the latter thereby becoming flatter in side elevation contour and moving the hook detent l1 away from the free end 26 of the electrode 20;

. to move away from the hook I! for breaking the circuit.

At times when the circuit becomes broken it remains open even after the disk has become cooled said circuit not being reclosable until an operator is informed, resultant from said breaking, that said circuit requires repair or adjustment after which said circuit may be manually and readily closed. In cases where said operator is inexperienced, should he manually close the electrodes l1 and 28 together and thereby close said circuitwithout adjustment or repair of the latter, said circuit and new, device immediately becomes reopened and prior to damage of the instrumentality 31.

From the foregoing description it is thought to be obvious that an electrical thermo-motive device constructed in accordance with my invention is particularly well adapted for use by reason of the convenience and facility with which it may be assembled and used, and it will also be obvious that my invention is susceptible of some change and modification without departing from the principles and spirit thereof and for this reason I do not wish it to be understood as limiting myself to the precise arrangement and formation of the several parts herein shown in carrying out my invention in practice except as claimed.

I claim:

1. An electrical device comprising a block of electrical insulating material, a bi-metallic disk of concavo-convex contour in cross section; said disk being normally of initial term sustaining character, a bolt electrode for attaching a medial portion of said disk to said block, a detent electrode secured to and in contact with said disk adjacent the perimeter of the latter, and a third electrode having a resilient arm portion carried by and electrically insulated from said disk, said detent and arm electrodes being spaced apart with respect to each other and adapted to be included in an electrical circuit. the free end 01 said arm being adapted to engage in said detent i'or normally closing said circuit, said disk being adapted to become deformed at times when an electrical current greater than a preselected'degree is applied to said circuit for releasing said arm from said detent for opening said circuit, whereby said disk becomes cooled and assumes its said normal initial form for reuse.

. 2. An electrical device comprising a bi-metallic disk of concavo-convex contour in cross section, said disk being normally of initial form sustaining character, an electrode secured to and in contact with said disk adjacent the perimeter of the latter, said electrode being provided with 4. In an electrical circuit opener, a metallic disk, oppositely disposed electrodes carried by said disk adapted to be included in said circuit,

. one of said electrodes being in contact with said a detent portion, and a second electrode having a resilient arm portion carried by and electrically.

insulated from said disk, said electrodes being spaced apart with respect to each other and adapted tobe included in an electrical circuit, the free end of said arm being adapted to en,- gage in said detent i'or normally closing said circuit, said disk being adapted to become deformed at times when an electrical current greater than a preselected degree is applied to said circuit for releasing said arm from said detent for opening said circuit, whereby said disk becomes cooled and assumes its said normal initial form for reuse.

3. In an electrical circuit, a bi-metallic member, two electrodes carried by said member, one oi said electrodes being insulated from said member and provided with a resilient swingable arm portion, the other electrode being in contact with said member and provided with a detent portion engaged with theiree end of said arm for normally closing said circuit through said electrodes, said member being adapted to become deformed at times when the electrical current carried "by said circuit becomes greater than a preselected normal degree, said member and electrodes being so constructed and assembled that at times when said member becomes deformed the r said free end moves away said circuit.

disk and the other electrode electrically insulated from said disk, means for causing said electrodes to normally engage each other for closing an electrical circuit through said electrodes, said disk and electrodes being so constructedand assembled with respect to each other that at times when said circuit is electrically energized in excess of a preselected degree said electrodes disengage for breaking said circuit.

5. A device, for the purpose described comprising a bi-metallic disk, two spaced apart electrodes secured to said disk, one of said electrodes being electrically insulated from said disk and the other in electrical contact therewith, a metallic spring arm having an end secured to one of said electrodes, means for causing engagement between the free end of said arm and the other electrode, said disk being so constructed that it becomes deformed when suflicintly heated for permitting disengagement of said arm and said other electrode, said disk being adapted to assume an initial form upon becoming of substantially initial temperature.

6. An electrical theme-motive device comprising a bi-metallic disk 01' concavo-convex contour irom said detent for breaking in cross section, an electrode secured to and electrically insulated from said disk having a swingable arm portion disposed across said disk, a detent electrode in electrical contact with said disk adjacent the perimeter thereof, the free end or said arm being adapted to engage in said detent, and resilient means for moving said arm away from said detent responsive to a change in the normal cross sectional contour of said disk.

7. A device as described in claim 6 having a knob of electrical insulating material adapted to .be pressed by an operators finger for moving the free end or said arm into engagement with said detent. v

8. An electrical device comprising a thermomotive electrode, a second electrode having a swingable arm portion disposed-across and electrically insulated from said thermo-motive electrode, a detent electrode in electrical contact with said thermo-motive electrode, the free end of said arm being adapted to engage in said detent, and resilient means for moving said arm away from said detent responsive to a change in the normal contour of said thermo-motive electrode.

CHARLES W.

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