US982557A - Reinforced grid resistance. - Google Patents

Description

H. J. WIEGAND. REINFORCED GRID RESISTANCE.

APPLIOATION rum) my 4, 1908.

982,557. Patented Jan. 24, 1911.

i l i i t l UNITED STATES PATENT OFFICE.

HENRY J. WIEGAND, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER-HAMMER MFG. (30., F MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

REINFORCED GRID RESISTANCE.

Specification of Letters Patent.

Patented Jan. 24., 1911.

Application filed m 4, 1908. Serial No. 430,844. i

To all whom it may concern:

Ile it known that I, HENRY J IVIEGAXD, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of \Yisconsin. have invented new and useful Improvements in Reinforced Grid Resistances, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawin forming a part of this specification. 31y invention relates to improvement in reinforced grid resistances and those of similar form.

One of the features of my invention is the peculiar construction of the reinforcing members.

Another feature of myinvention resides in.thc manner of securing-the reinforcing members to the resistance units.

Another feature resides in the -manner of insulating the reinforcing members from the resistance units.

In order that my invention may be more thoroughlyunderstood I have. illustrated one embodiment thereof in the accompanyin g drawing. i

In the accompanying drawing-Figurel is an'clevation of a reinforced grid resistance crnlmtving my invention. Fig. 2 is a sectional view taken on line B -2, Fig.1. Fig.1; is'nli enlarged sectional view taken on line ;3, Fig. l. and Fig. t is an enlarged sectional view taken on line. -"t-4, Fig. 1.

My invention applies to resistances which consist more particularly of a reflexed strip or bar having a number of convolutions, as for instance, a grid resistance A, such as shown in the drawin The grid resistance 'which is shown in the drawing is a type which is used extensively in practice. Itis, usually made of castiron but may be made of other suitable material. Inasmuch as the grid consists of a long reflexed bar it is more "or'less flimsy and may be bent or distorted very easily. v

. My invention provides special reinforcing means for firmly holding the convolutions to strengthen the grid as a whole, and make it rigid, so as to prevent it from being bent or distorted. The, outer bars a of the grid are provided with suitable terminals a", by means of which the grid may be fastened in position and electrically connected in circuit. The terminals a are disposed at the tightly grip the gri grid at a central point. These terminals may, of course,-be arranged in any suitable location and may be of other forms than that shown, I prefer to make the other bars a of the grid of the same length as the intermediate bars, for the purpose which will be hereinafter set forth. Over the edges of the grid on opposite sides, or in other words, overthe ends of the bars or convolutions, I- place reinforcing strips B, preferably substantially U-shaped inores section. a Each of the. reinforcing members is providedfwith several ribs or heads I), which are preferably stamped u' therefrom to strengthen'itit'ransversely. etweeneach of the reinforcing strips and the grid I interpose 'an'jnsulating middle of the outer bars so'as to support the i. I

strip C, made of any suitable material, to

insulate the reinforcing strips from the grid. Of course I may use any means for this purpose. It is preferable to bend the sides of the reinforcing stri s inwardly so as to Of course the rein forcing strips might be so formed that it; would be necessary to spread the sides'th'ereof apart in order to put them on the edges of the grid and then the tendency of the sides to spring inwardly would naturally cause them to firmly grip the grid. In order to hold'the reinforcing strips firmly in-plaee I preferably indent the sides thereof to form inward projections b, which enter t he'spaces a between the bars at their looped ends. The reinforcing strips are thus firmly held in place and can only be removed after the projectiong b have een priedout of the slots a. At the points where I indent thereinforeiyg strips I preferably interpose additionalinsnlating material D, such as mica, between the reinforcing strips and the grid so as to insure perfect insulation between the same.

placed over the edges of said grid and having transversely extending ribs formed thereon.

2. The comblnation with a grid resistance,

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of substantially U-shaped reinforcing strips placed over the edges of said strips and have mg transversely extending strengthening ribs formed thereon and means for insulating said reinforcing strips from said grid.

3. The combination with a grid resistance, of substantially U-shaped reinforcing strips placed over the edges of said grid, said remforcing stri 5 having projections formed on the sides tiiereof and extendin into the spaces between the looped ends 0 the bars of said grid.

' 4. The combination with a grid resistance, of substantially U-shaped reinforcing strips placed over the edges of said grid, said re 1nforcing strips having projections formed on the sides thereof and extending into the spaces between the looped ends of the bars of said grid, and means for insulatin said reinforcmg strips from said grid, sai

insulating means belng reinforced contigubus to the projections on said reinforcing strips.

5. The combination with a grid resistance,

' of substantially U-shaped reinforcing strips placed over the edges thereof and having transversely extending I'lbS formed thereon,

extendin intothe spaces between the looped ends of t e bars of said grid. v

6. The combination with a grid resistance,

.of substantially U-shaped reinforcing strips placed over-the edges of said grid and havmg transversely extending strengtheningribs formed thereon, a str p of insulating material interposed between each of said reinforcing strips'and said grid, each of said reinforcing" strips having -1nward projections formed on .the sides thereof andea"- tendin into the spaces between the loo )ed reinforcing stri s and ends 0 the bars of said 'grid,'a'nd ana di tional Strip bf u ing n1ateria1' j'nter.---"" JQCtlOIlS on said reinforcing members;

. posed between tlie'grid and each of the pro! In witness \vhereof, I'have hereunto sub scribed my name' in the presence two? witnesses.

HENRY J. WIEiiKfin Witnesses W. HOPKINS, Tnnonoan LINCOLN.

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