US2636960A - Enclosed switch - Google Patents

Description

April 278, 953 R. N. RowE 2,636,960

ENCLOSED SWITCH Filed March 15, 1950 2 SHEETS-SHEET l IIN" ' INVENTOR. P41/AMA@ /14 {0h/f Patented Apr. 28, 1953 ENCLOSED SWITCH Raymond N. Rowe, Plainville, Conn., assignor, by

mesne assignments, to General Electric Company, a corporation of New York Application March 15, 1950, Serial No. 149,849

('Cl. 20G-133) 3 Claims. 1

Modern electric apparatus especially enclosed switches employ cartridge type fuses. Sometimes these fuses have flat blade terminals and sometimes cap terminals. In any case, the fuses are removably supported by clips or clamps of various types.

When current is iiowing through a switch, the fuses, being thermally functioning devices, generate heat, and since this heat has no ready means of escape, the fuses and adjacent terminals bec-ome very hot, and in time heat up the air in the switch enclosure, cause oxidation and annealing of various parts and increase of contact resistance at the fuse holders.

It is the main object of my invention to provide practical means applicable to various types of enclosed devices for preventing the overheating of the fuses and clamps and consequent damage.

It is another object to protect enclosed switches.

It is another object to protect enclosed devices having multiple fuses.

I have accordingly provided means for conducting heat from the fuse holders and radiating it outside the switch receptacle. For this purpose, I provide metallic rods or tubes thermally connecting the fuse holders but electrically insulating the rods or tubes which rods or tubes are connected to the opposite side walls of the receptacle and preferably to radiating ns or plates outside of the receptacle.

The accompanying two sheets of drawings show the preferred embodiment of the invention and one modification.

Fig. l is a front view of an enclosed switch embodying one form of my invention, the cover being broken away to show the interior.

Fig. 2 is a plan view of the form of Fig. 1, parts of the receptacle being broken away.

Fig. 3 is a side view of the radiating plates of Figs. 1 and 2.

Fig. 4 is a horizontal section showing a fragment of the thermal radiating members of Figs. 1 to 3 taken on the plane of the line 4-II of Fig. 2.

Fig. 5 is a fragmentary sectional view taken on the plane of the line 5-5 of Fig. 2.

Fig. 6 is a front view showing a radiating rod with fuse terminal connections.

Fig. 7 is a side view showing one form of switch unit with fuse clamps and radiating rods.

Fig. 8 is a fragmentary horizontal section showing another form of radiating members.

The body I of the receptacle and the cover 2 are usually of metal, and enclose switch snap action and switch contact mechanism and fuses. In the form shown, the base 3 carries snap action mechanism of any suitable type. My Patents 2,468,463 and 2,475,338 and 2,494,314 may be referred to as suitable but not as limiting the invention herein claimed to such forms. The base is supported on flanges 4 at opposite sides of the receptacle and secured by screws 5. An actuating shaft 6 extends through the cover and is provided with a suitable handle (not shown).

The switching device 'I may be of any suitable type such for instance as that shown in my Patents 2,468,235 or 2,494,315 but the present invention is not limited to any special form. The movable switch member 8 is actuated by the crank shaft 9 from the snap action mechanism in base 3. The cross bar I0 extends across the receptacle and serves to actuate the various switch units, in this instance, three.

Each switch unit 'I has circuit terminals II and I 2 of any suitable form and is provided with a circuit protection fuse I 4 of any suitable form. In Figs. 1 and 2 and 5 the fuse has conventional cylindrical caps or ferrules and is removably mounted in spring clips I5, I5 of conventional form.

A fuse clamp I5 of Fig. 5 is mounted on each of a pair of spaced fuse terminals I6 on each switch unit by means of the extension I 'I and screw I8. A metal rod I9 is connected to a fuse clip of each of the transversely situated switch units 'l by means of metallic 'straps 20, the ends of each ofveach of which are secured by a screw I8. Each strap encircles the rod I9 but is electrically insulated from its clamp by an insulating sleeve 2l which may be applied in any suitable manner. This strap may be perforated at 22.

A rod I 9 extends across the outer side of the upper row of the fuse clamps and a bar I9 extends across the lower row of the fuse clamps, the fuses extending between the respective pairs of fuse clamps being substantially parallel as shown.

Each end of each rod is secured to a side wall of the receptacle by a screw 23 so as to radiate heat conducted from the transverse rods.

I also prefer to provide radiating metal plates 24 and 25 secured to the rods by screws 23, and 23 but spaced from the wall l by washers 26 and 26 so as to permit air to circulate around the plates.

In Fig. 6, I have shown a modication in which the various fuse terminals are insulated individually from the radiating cross members by insulating sleeves 3B which are inserted between the terminal straps 20' and the member I9. A

a layer of metal foil 3l may be interposed between each strap and sleeve to increase local thermal conductivity.

In Figs. 6 and '7, the fuse I4' has terminal blades mounted in fuse clamps l5' such as set forth in my Patent 2,453,019. The form of clamp however is immaterial to the present invention. The endofastrap .28 .issecured `between the `fuse terminal I6 and.clamp."|5. 'l

In Fig. 8, I have shown a tubular radiating cross member lS which is mounted in the recepr tacle by means of a screw threaded sleeveZBY. These sleeves may also support radiating 'plates 24x. These tubular radiating Amembersprovide increased radiating surfacesrand'lirlmt.circulation of air through the tubes.

From the foregoing, it will be seen that the cross rods or tubes constitute` thermallylndcltive heat radiating extensions from thevarious fuse terminals and that they conduct heat to the anfar angement is especiallyyalluable for 12mg haunggefrectj 'Q'f the enclosed -ft-v36311111einentsHieke` it nesafy ,enclos'e'the vruses that 'direct'.radiation: from 'sible.""

theformishown, theA crossrods kor ,tubes not electrically cbnnlati thereto .and Supporting Aone. @ad-ef la fuse'. extending 'between fee-111 reir Qfrs-aid-Qlipsrsaid Contact Clins-abelis-Iiesd .Sunmaimerasf t,- @Xtendin @We IQWS' -ClQSS Asaid receptacle, two heatconducting rodsv inf'said enclosure extending across said enclosure respectively. adjacentsaid rows of Contact clips, aplu- ,rality of ,heat conducting members secured to each .of lsaid .rods in electrically` insulating heat conducting Arelation vwith said ,rods and secured .,eachito one of said contact clips in heatconcluctying' relation therewith, .and meaiisfor securing opposite Walls of .said enclosure .against the ,ends loflsaidflrods so.' as toformfa heat vconducting .re-

2T The combination `in an .enclosed switch, metalA walls forming an enclosure, fa plurality of .switching devices mounted infsaid enclosure, a

pair offfuseitrminalslneach of said'v switching devices, aconta'ct clip secured to Teach of said terminals -for.electrically',connecting thereto and supporting one .end of a fuse extendingbetween each pair of said clips, said contact clips being positioned in such manner as to extend in two rows across said receptacle, two heat conducting rods in said enclosure extending across said enclosure respectively adjacent said rows of contact clips, a plurality of heat conducting members secured to each of said rods in electrically insulat- .ingheatconducting relation withlsaidnrods and se'curedxeach toone of said contact, clips in heat conducting relation therewith, a heat radiating alnsttheoiiterfsurface of its said wall and the heatradiating member.

' 3. The lcombination in an enclosed switch,

elect-fiala. conceding thereto.aadfsuprrtone end oa fils@ @Xiediee :between each pair fof'said clips, said contact-clips being positioned lin ai@ 'meneer that, said fuse a 11.1.1 'substantial parallelrelation Ywitheachother and Lsalidcl' ,maand poripns irl. enseeinentwith, each other Y Ithriasfsad said. @radiales rs

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