US2590605A - Series lamp cutout - Google Patents

Description

March 25, 1952 F/W, GODSEY, JR

SERIES LAMP CUTOUT Filed March 28, 1950 INVENTOR Frqnk W. Godsey,v Jr.

Patented Mar. 25, 1952 UNITED STATES PATENT OFFICE SERIES LAMP CUTOUT Frank W. Godsey, Jr., Pittsburgh, Pa., assigner to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application March 28, 1950, Serial No. 152,419

8 Claims.

My invention relates, generally, to switch desimple, reliable and compact construction, and

which may be economically manufactured and used.

A more specic object of my invention is to provide a cutout device embodying a thermally controlled or released mechanical switch element.

Another object of my invention is to provide l a cutout device `wherein the short-circuiting or circuit-closing operation is performed by a resilient or fiexible contact element which is released from a normally open position to a contact making position in response to a predetermined increase in the temperature of the device resulting from increased voltage applied thereto due to lamp failure.

A further object of my invention is to provide a cutout device of the character described wherein the shunting or circuit making operation is effected by a flexible contact spring normally retained in an open position by a quantity of solder which is melted to release the contact spring in response to an increase in the operating temperature of the device due to the interruption of the series circuit through the lamp.

A still further object of my invention is to provide a cutout device of the character described wherein the contact spring is normally held in an open or retracted position by a thermally responsive latch member or device which is actuated in response to a predetermined increase in temperature to release the contact spring.

Another object of my invention is to provide a cutout device of the character described wherein the necessary heat to trip or release the contact spring is produced in the device itself by passing current through a small block or ring of non-linear conducting material.

It is also an object of my invention to provide a cutout device of this kind which may be reset or readjusted to its normal operating condition after it has once operated to short-circuit the lamp.

These and other objects of my invention will be more readily understood from thefollowing detailed description, when considered in conjunction with the drawing, in which:

Figure 1 is an elevational view, in section, o a cutout device embodying the principal features of my invention;

Fig. 2 is a sectional view taken along lines II-II of Fig. l;

Fig. 3 is an elevational view, in section, of a modification of my invention; and

Fig. 4 is a sectional view taken along lines IV-IV of Fig. 3. v

In practicing my invention in its preferred form, the cutout device is formed in the usual button or wafer shape and comprises a spacer element in the form of a block, a pair of blocks', or a ring of fused silicon carbide clay pressed or held between two metal discs constituting the contact plates or terminals of the device. The spacer, in whatever form it may take, is of such nature that a recess or cavity is formed in the device in which the switch or contact making element is positioned. In one form of my invention, a spring contact member is rigidly attached at one of its ends to the interior surface of the upper plate, and its opposite free end is normally biased by spring action to engage the other or lower plate. The free end of the contact spring is normally held out of engagement with the lower plate by soldering it to the inner surface of the upper plate. The current flowing through the spacer element in response to lamp failure results in the development of a suicient amount of heat to melt the solder and thus release the contact spring to a circuit making position. In a modication of my invention, the Contact spring is held out of contact making engagement with the lower contact plate by a small bimetallic latch member which likewise functions to release the contact spring as a result of heat developed in the spacer element as before.

Referring now to Figs. l and 2 which show the preferred embodiment of my invention, it will be observed that one contact plate l0, which may be termed the upper plate, is in the form of a solid fiat disc, and the other contact plate, which may be termed the lower plate, is in the form of a nat bottomed cup Il having a bottom portion l2, and an upright or side portion i3.

As shown in Fig. 2, the spacer element for the contact plates is formed in two parts or blocks l5 and I6 spaced apart to provide a central elongated cavity l1. These spacer blocks twithin the cup H, resting directly upon the bottom portion I2 of the cup, which in this instance is the lower contact plate, and are tightly held therein by the upper plate l0 which may be secured in any suitable manner, such as A.millingand packingat a high temperature.

by crimping or otherwise forming the upper edge I8V of the side of the cup II as shown in Fig. 1.

The plates III and I2 may be insulated from each other by suitable insulating material 2I, such as fish paper, which is placed within the cup II around the spacer blocks and bent over under the crimped portion vas shown in Fig. 1. It will be understood that this insulates the contact plates from one another so that when a voltage is impressed across the device, that is across the plates I and I2, the current must flow through the spacer blocks I and I6.

The plates I0 and I2 may be formed of any suitable material, such as copper, brass, etc., which is easily Worked or formed and which has good electrical qualities.

The spacer blocks I5 and I6 may be formed of non-linear conducting materials such as coppermaterial such as fused silicon carbide clay. This ...material .is Aof a ceramic nature and as formed by mixing silicon carbide crystals with ball clay, The surfaces of the blocks are made conducting by .spraying or.otherwise applying 'a suitable metallic coating.

.This preferred material has a non-'linear con- -duction characteristic which providesfor greatly increasedcurrent flow as the voltage increases. .Asanexampla the .current mightbe 5 milliamn peres,at..50 volts,.20 milliamperes at 57 volts, and 3.amperes-,at'200 volts, depending upon'the exact v4characteristicof the material` which may be varied .over an-.appreciable range of manufacture.

Theswitch or .contact making element of the deviceis in the vform of a at leaf spring 22 of .Phosphorbronza or the'like, having one end 23 '.-rigidly vattached Vto the interior surface of the upper plate. Illby means of a rivet 24 or otherwise,

v and .its ,other or free end 25 attached `to this fsamefcontactplate by means of a small quantity of 50-50 solder-or the like as indicated at'26 .in Fig. 1. It Ywill .be understood that the contact spring .22.is to .be held in a substantially flat posistion against the 4bottom surface yof the upper :contactplate I0 with its free end 25 out of en- ;gagementiwith the bottom plate I2. The spring is so shapedor biased that when it is released 5 :by the'melting of ,the solder, thefree end 25 will -.snap intofengagement with the contact plate I2 v`the-casing rformedxby the cup II and the upper :contact-plate |10.

.Iffdesired, the lower contact plate I2 may be .providedwth a small opening 2`I directly. beneath vthe-freev end 25 of the --contact spring so that a -fsuitable instrument may be inserted to push the freed end lof the-contactspring back to its normal l,position .once it has A.been released. This makes itgpossible vto reset the cutout deviceto its normal .operating .condition by applying sufficient heat by :means of ra .soldering iron to the upper plate I0 .-toremelt .the solder 26 and thus again detachably .secure'the free .end .25 of the contact spring to theaupper plate.

Referring .now to'Figs. 3 ,and 4 which show a V.modification of my. invention, it will be observed that in'this instance'the lower contact vnlate'3l 4 is in the form of a flat disc and the upper contact plate 32 is formed as a shallow cup-shaped element of the same general shape, but having a circular indentation 33 which is clearly shown in Fig. 3.

In this instance the spacer element is in the form of a ring 34 and is comprised of the same material as the spacer blocks I5 and I6 of the preferred embodiment. The contact plates 3| and 32 may be securely held in position on opposite sides of the spacer ring 34 in any suitable In this embodiment the contact spring 35 is mechanically controlled or released by means of a small mechanical latch 36 which may be formed of bimetal. As shown best in Fig. 3, the contact spring 35 -is rigidly attached by means of a rivet 31, or otherwise, to the upper surface of the contact plate 32, and is .provided at its free end 38 with a contact 39 extending through a small 'opening 4I in the contact plate. yThis contact Lspring is normally shaped orbiased so that vit moves down and causes the contact element 39 to engage the lower plate 3 I.

The thermally responsive latch member 3B is shown best in Fig. 4. It may be L-shaped and attached at'one end 42 vto the contact plate 32, and so 'positioned with vrespect to the contact rspring-35 that its end portion 43 normally engagesthecontact spring -andholdsit ina raised vposition'with the contact member 3S out 4offengagement with the lower plate 3I. Any other `suitable arrangement or shape of latchmay be used.

'It will be understood that, `in this instance, when thedevice is subjected to more than its normal operating voltage, the heat generated by "current lowingthrough thespacer ring 3l! .will `cause the latch 36 to release the contact spring Thev device may be reset forfurther operation bysimply raising the contact spring and re-engaging the end of the latch member 36 therewith.

In view of the foregoing detailed description lof the two-embodiments of'my invention, it will "be apparent that I have provided a new type of seriesy cutout device which vis in the form of a "positive'acting switch mechanism. The device,

in Veither of its two forms, is of a simplenaturc 'and isy economical to "manufacture and use. It is 'a-positive acting'device which may be used over illustrative of the several different forms my invention may take.

I claim -as Vmy invention: n1. An electric cutout device comprising, two

-conducting surfaces, spacer means disposed in Acontact relation therebetween, said spacer means being-formed of -a non-linearconducting material, a movable 'contact member mounted onone of said surfaces,l a thermally responsive lmeans normally retaining said contactmember in an' open; position, and operable to connect said Asurfaces together when heated to a predetermined degree by current ow through said spacer means. Y'

2. An electric cutout `device comprising, two conducting surfaces, spacer means disposed therebetween. saidv spacer means being'fcrmedl of a non-linear conducting material and so shaped as to provide an elongated inner cavity, a movable contact -member mounted in said cavity operable when in its closed position to connect said surfaces, and thermally responsive means normally retaining said contact member in an open position and operable to release said contact member to its closed position.

3. An electric cutout device for series lighting circuits and the like comprising, a pair of spaced contact plates of conducting material, a pair of spacer blocks disposed therebetween and in intimate contact therewith, said blocks being formed of a non-linear conducting material and being spaced apart to provide an elongated channel between the plates, and a contact spring mounted in said channel with one end rigidly secured to one plate and its opposite end soldered to the same plate, whereby said other end is releasable by the melting of the solder and operable to engage the other plate.

4. An electric cutout device for series lighting circuits and the like comprising, a pair of spaced contact plates of conducting material, a spacer ring of non-linear conducting material disposed therebetween, a movable contact element attached to one of said plates and biased into engagement with the other plate, and a thermally responsive latch attached to said one plate for normally retaining said contact element out of engagement with said other plate.

5. A cutout device for series lighting circuits and the like comprising, a cup-shaped member o conducting material having a flat bottom portion, a pair of spacer blocks of non-linear conducting material disposed in said member, said spacer blocks being spaced apart to provide an elongated channel, a fiat disc-shaped member of conducting material disposed in the cup-shaped member over the spacer blocks with the upper edge of the cup-shaped member crimped over upon the disc to retain it in position, insulation disposed between said cup-shaped member and the disc, and a thermally responsive contact member disposed in said channel normally engaging the disc-shaped member and operable in response to a predetermined rise in temperature resulting from the passage of electric current through the spacer blocks to also engage the bottom of the cup-shaped member.

6. A cutout device for series lighting circuits and the like comprising, a pair of conducting members, spacer means interposed therebetween and in intimate contact therewith, said spacer means being formed of a fused silicon carbide clay having non-linear conducting characteristics, a movable contact member mounted on one of said surfaces and thermally responsive means normally retaining said contact member in an open position, and releasing said movable contact member to engage both surfaces in response to the development of a predetermined amount of heat in the spacer means as the result of current iow therethrough.

'7. A cutout device for series lighting circuits and the like comprising, a pair of metallic plates, a pair of spacer blocks interposed therebetween and held in intimate Contact relation therewith, said spacer blocks being so positioned relative to each other as to form a cavity between the plates and being formed of a fused silicon carbide clay, a contact spring rigidly attached at one end to one of said plates within the cavity and biased to engage the other plate with its free end, and thermally responsive means mounted on said one plate functioning to normally hold said free end of the contact spring out of engagement with said other plate.

8. In an electric cutout device for series lighting circuits and the like comprising, a pair of spaced contact plates, a spacer ring of fused silicon carbide clay interposed therebetween, one of said plates being substantially flat and the other being shallow cup-shaped with a flat bottom portion extending downwardly within the ring and having an opening therein adjacent one side, a contact spring mounted within the cavity formed by the cupped plate with one end rigidly secured thereto and the other end carrying a contact member extending through said opening in the bottom of the cupped plate, said contact spring being normally biased to cause said contact member to engage the fiat plate, and a bimetallic latch `member mounted on the cupshaped plate normally functioning to hold the contact-spring in a retracted position and operable in response to predetermined temperature conditions of the cutout to release the Contact spring.

FRANK W'. GODSEY, JR.

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

UNITED STATES PATENTS Number Name Date 1,795,741 Shoenberg et al. Mar. 10, 1931 2,835,616 Shoenberg et al Dec. 8, 1931 1,898,174 Dubilier Feb. 21, 1933 1,960,408 Brach May 29, 1934 1,971,194 McEachron et al. Aug. 21, 1934 FOREIGN PATENTS Number Country Date 850,975 France Sept. 25, 1939

Images