US1080947A - Casing for resistances. - Google Patents

Description

A. W. BERRESPORD.

CASING FOR RESISTANCES.

APPLICATION FILED JULY 10, 1909.

Patented Dec. 9, 1913.

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WIT $535,365

' To ollt whom it may concern:

" Be it known'that I, ARTHUR W. Burmes- STATES rigour owner-i,

ABTHUB W. B-ERBESIORD, F IILWAUIEE, WISCDNGIN, ABSIGNQB TO THE CUTLER- HAHKER MFG. 60., OF MILWAUKEE, WISCONSIN, A GDRPORAT-IQN 0F WISCONSIN.

GASIHfi EUR BESISTANCES.

FORD, a citizen'of the United States, residing at Milwaukee, 1n the county of Milwaukee fend State of Wisconsin, have invented new and useful Improvements in Casings for I Resistances, of which the following is a full,

clear, concise, and exact description, reference being had to theaccompanying drawing, forming a part of this specification.

My invention relates to improvements in L lIlClOSlIlg casings for resistances.

v "Vh'ere resistances are inclosed for the pur pose of protection it is customary to provide apertures in the inclosing casing to permit a. free circulation of air between the resistance 11111138 to prevent the same from overheating. Such apertures a're usual y provided in the top and bottom of the casing as this arrangement insures the best ventilation. Even though inolosed resistances are ell'yentilated, they are, nevertheless, apt to become overheated and burn out. 7 This [causes the formation of arcs tending to pass upwardly through the apertures in the top of the casing. Furthermore, uponburuing out of the resistances molten resistance material and solder flow through the open tures in the bottom of the casing. Consequently, with ordinary inclosing casings there is great danger of starting fires upon 5 the burning outof the resistances. 4

My invention, therefore, has for its object t to provide a casing which will insure proper ventilation ofthe resistances and also pre- "vent the escapement of any flames or molten material therefrom upon the burning font of the resistances.

For the purpose of the nature of my invention, I shall describe the emhodiziielit thereof illustrated in the accompanying drawing. It should be under.-

:stood, however, that my invention is not limited to the particular structure shown in the drawing, but is capable. of various modi fieations.

plied .theretMFigs, 2 and 3 are perspective 9 In the drowing, Figure 1 iso perspeotiye view of e device having my invention apvlews of parts of the device. l is a on i l se ti na i taken through aportion'oi the. device; and Fig. 5 is a permore fully disclosing v lnecimtion of Letters Patent. Application filed July 10,1909. Serial No. 506,934.

1 sides of the I have shown lugs 12 having angular por-i Patented Dec. 9-; 1913.

of which I shah now des ribe- In racti e, the asing m y ass me various diflerent forms. The particular casing illustrated is in the form of a rectangular box, being provided with a back 8,' side xpieces 9, a to and a bottom 11. The QX may be ormed of any preferred size and of any preferred material, Furthermore, the box'ma be constructed in various iifirent ways, illustrated, the buck and are formed integrally, while the top end bottom thereof are formed of separate pieces. For supporting the casing,

tions to Whichth sides and top and bottom of the hex are secured-by suitable means,

such as rivets 13 or screws 14*. In practice, the resistance unitsmey be mounted either in the casing or on the hack of the insulating panel 4;. However, it is customary to mount the units in the casing. This may be done in various difiierent Ways. One method of mounting the resistance units in the cas in is shown in Fig. 2, As illustrated in this figure" the resistance units 15 are mounted vertically in the casing and spaced a suitable distance apart, To insure proper ven tilation of the units 15, I have provided apertures 18 inthe top and bottom of the ossing This permits a free circulation. of air-through the casing, to prevent overheating of the units 15.

To prevent escapement of molten metal through the apertures in the bottom of the casing, I preferably provide :1- receptacle 19 adapted to be secured to the underside of the bottom portion 11 in any preferred manner. As illustrated, the rece itacle l9 n erely nomprises an oblong pan of the some w dth and depth asthe casing and having inolined side port ons, For secur ng the receptacle 19 to the casing I have shown screws 20 adapted to fit into screw threaded apertures 21. in the bottom portion It. In order to prevent. the receptacle 19 from obstructing the circulation ot air through the ventilating apertures, I preferably provide spacing washers 2L surrounding the screws 20 which maintain the receptacle It) at. a suitable distance from underside of the casing.

For preventing the escapenient of flames from the casing, upon burning out of the resistance units, l. have provided a hood, the structure of which .1 shall now des ribe. This hood comprises an outer portion 25 and an inner portion 26. The hood is preterabLv of substantially the same width and deptlnas the top It) oi the casing and is adapted o rest directlygthereon. The opposite endsol the inneiganil outer members are closed, while the other ends thereot are open, thereby providing a tortuous line for the eseapement of air and gases passing through the apertures in the top of the casii'ig. In practice, the hood may be. formed in any preferred manner and securml to the casing by any preferred means. As illustrated, the hood is adapted to be secured to the casing by means of a screw :27 adapted to tit into a screw threaded aperture 28 in the top 10 of the casing. The hood is preferably arranged to snugly titbet ween. the supportinglugs at opposite sides of the casing so as to prevent the same turning. The portion 26 of the hood in reality forms a ba'tlie plate for detlecting any flames produced upon the burning out of the resistances. The path provided for such flames, as indicated by ar rows, insures the cxtinguishmcnt thereof bclore the can leave the hood. While it may appear that the hood obstructs the circulation of air for ventilation, it has been found in practice that it does not deso to any appreciable extent. (-oi'isequent-ly, the casing thus produced not only provides for proper ventilation, but obviates all danger arising from the production of flames and molten metal. upon the burning out. of the resistances.

In Fig. 5, l have illustrated the preferred manner of 'l'orn'iing the member 2G ot the hood. This construction provides upwardly extending' ide pieces 30 which form means for maintaining the members 2a and 25 in a spaced relation without the use of any speial fastening means.

Having thus described myinvcntion what I claim as new and desire to secure by Letters Patent is 1. An inclosing easing tor resistances having a reflex ventilating flue.

Q. Arheostat comprising a resistance ele ment ,"an inclosing casing therefor, said casing having ventilating openings in its top the' ing ventilating apertures in the top thereof and a hood arranged on the top thereof, said hood having a tortuous flue therein.

Au iuclosing casing for resistances comprising a box portion having ventilating apertures in the top and bottom thereof, a hood arranged on the top of said boX portion and having a. ballle plate arranged therein and a hollow recepta le disposed below the apertures in the bottom of said box portion.

ti. A hood for resistance inclosing casings having a reflex opening therein.

7. hood for resistance inclosing casings comprising an elongated member substantially U-shape in cross section and closed at one end and a batlle plate arranged within said number to term a tortuous fine.

8. A" hood for resistance inclosing casings comprising two elongated portions substantially Ushape in cross section, and arranged one within the other, said portions having opposite ends thereof closed and being spaced from one another to form a tortuous tine.

t). In a rlieostat, the combination with a box body having open ends, of a pair of plates closing said ends and held by the box body, resistance coils supported between said plates, said plates having ventilating apertures therein, and guard-pieces covering the ends of the box body at a distance from said plates leaving a space between the said ends of the box body and the plates, said space conninmicating with the atmosphere, Whereby a circulation oi air is permitted.

it). in a rlieostat, the combination with a box body ha ving top and bottom plates provided with ventilating apertures therein, re-

sistance coils supported by and between said plates and removable guard p eces covering the apertures in said plates, said guard pieces and said plates being spaced to permit circulation of air through the ventilating apertu es in said plates.

11, in a rheostat, in (annbination, an insulating panel for the resistance controlling contacts, a resistance casing secured to said insulating panel, said casing having top and bottom plates provided with ventilating apert ures therein, said casing and said panel together forming an entir ly closed receptacle except for the ventilating apertures in In Witness whereof, I have hereunto subthe top and bottom plates, resistance units scribed my name in the presence of two witsupported between said plates, and top and nesses.

bottom guard members covering the ventilat- ARTHUR W. BERRESFORD. ing apertures in said plates but spaced from Witnesses:

said plates to permit circulation of air FRANK H. HUBBARD,

through the ventilating apertures therein. S. V.FI'1-ZGERALD.

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