US1719179A - Resistance device - Google Patents

Description

y 2, 1929- H. T. HAYDEN. JR 1.719.179

RESISTANCE DEVICE Filed July 19, 1926 2 Sheets-Sheet 1 oooooooooca awoentoz flzzry Zflaydmfi 351 W (lame/1 4 A W mg-v 6M y H. T..HAYDEN. JR 1.719.179

RESISTANCE DEVICE Filed July 19, 1926 2 Sheet s-Sheet 2 o I v o 44 @194 i 4.5 @5 Q/zz s K x 9 TH mkhe ,5 2 Z3-- m7 y s 2 a'vweutoz 1/6/2131 THql/dm J! 93 4M abto'mwlp Patented July 2, l92 9.,.

UNITED STATES PATENT OFFICE.

HENRY T. HAYDEN, JR, OF NEW YORK, H. Y., ASSIGNOR T0 WARD LEOITABD ELECTRIC COMPANY, A CORPORATION OF .NEW YORK.

nnsrsrmcn DEVICE. f

Application filed my 19,

This invention relates to electric resistors of the sheet metal type and to the method of constructing the same.

The principal'objects of my invention are to provide a resistor of this character hav ing a continuous resistance element or conductor of improved form, and to provide an improved method of constructing such resistor wherein the continuous resistance element is formed from a single sheet of metal'with'little or no waste of material.

' Further objects are to provide an improved resistor which is simple, light, strong and durable in construction, economical in cost of construction and eflicient in operation. Such a resistor may consist of a single suitably mounted resistance element or may comprise a plurality of such elements, each of which, with its mounting, forms a separate resistance unit of the resistor, and a further object of my invention is to provide an improved resistor comprising a plurality of such units.

Other objects of my, invention will appear from the followingdescription taken in connection with the accompanying drawing,.wherein Fig; 1 shows a sheet metal blank from which a resistance element, employed in one form of my resistor, is made.

Fig. 2. is a side elevation, partly in section, of a resistor or resistor unit emplding a resistance element formed from t e blank shown in Fig. 1.

Fig. 3 is asectional view taken on the line 3-3 of Fig. 2.

Fig. 4 is a view similar to Fig. 2, but showing a resistor having a resistance element of somewhat modified form.

Fig. 5 is a view'similar to Fig. 1, but showing a modified form of sheet metal resistance" element blank.

Fig. 6 is aside elevation of a modified resistor or resistor unit employing a resistance element formed from the blank shown in Fig. 5.

Fig. 7 is a partly diagrammatic top plan view of aresistor employing a plurality of the resistor units such as is shown in Figs. 2, 4 or 6. g Y

The blank shown in' Fig. 1 is formed of a flat sheet of resistance metal in which has been formed a series of-parallel staggered slits 11, extending inwardly from opposite edges of the sheet and over-lapping one anm. Serial 110. 123,291.

the slits 11 and the free ends of the end.

strips have terminal ortions 17 formed with openings 15, whic are located inline with the outer edges of the end strips. The blank of the form shown in Fig. 1 may be readily made from a flat sheet of metal by stamping and cutting.

Referring to Fig. 2, 20 represents a zigzag resistance clement formed from the blank shown in Fig. 1. To form the resistance element 20 each of the connecting portions 14 are turned so that they lie parallel with one another and the axes of all of the openings which lie along each edge of the blank are in alignment. Thus, the connecting portions 14 along the bottom of the sheet and theterminal portions 17 may be given a turn of 90 in a clockwise direction when viewed from the bottom of the sheet as shown in Fig. 1, and each of the connecting portions 14 at the top of the sheet may be given a turnof 90 in a counter clockwise direction when viewed from the bottom of the sheet. The result vof turning the connecting portions and the terminal portions in this manner is to twist each of the strips 12 to 180 as is indicated in Fig. 2.

The resistance element 20 when formed as above described, is mounted on two parallel metal rods 22'and 23, which extend respectively through the upper row of openings 15 and through the lower row of openings 15 in the resistance element 20, and are securedat their ends to supporting channel bars 21. The successive connecting portions 14 of each row are spaced from one another and form the supporting rods by insulating sleeves 24, each of which is formed with a boss 26 which extends through the opening 15 into a recess or seat 27 formed in the adjacent sleeve. Each row or series of 1nsulating sleeves and spaced" connecting portions 14 is firmly held on the supporting red by nuts or screw threaded washers 30,

which are. mounted on screw threaded portions 34 of the rods and bear against the end sleeves of the rows. Term inal clamps 35 In Fig. 4 I have shown'a resistor having a somewhat modified resistance element 44, wherein each of the connecting strips 45 is formed with a longitudinal strengthening rib 46, and each of the strips are twisted through 90 at points beyond the ends of the ribs instead of being, twisted throughout the length of the strip as in the form of resistance element shown in Fig. 2. The resistance element 46 is made from blank of similar form to that shown in Fig. 1, except that the blank has the ribs 46 stamped therein.

In the zigzag resistance elements shown in Figs. 2 and 4, successive strips are oppositely and'equally inclined to the vertical. In the form of myv invention shown in Fig. 6, alternate strips 50 are vertical and the remaining strips 51 are inclined to the vertical. It will be noted that in this form of resistor the distance between openings 15 at the opposite ends of a vertical strip 50 is somewhat less than the distance between the openings at the opposite ends of an inclined strip 51. To provlde for this difi'erence in the lengths of the strips as measured from the opening at one end to the opening at the other end, and also to insure the alignment of the openings at the lower .ends of the strips and the alignment of the openings at the upper ends of the strips, when the resistor is bent into the form shown in Fig. 6, I employ a blank shown in Fig. 5 in which the openings along each side of the sheet are located on a line which'is inclined'to the normal of the slits 11. The slits 11 termlnate in the sheet at points which lie on lines parallel to the lines joining the centers of the openings 15 and the side edges of the blank are preferably stepped. as shown at 55 so that the connecting portions 56 which ]0lIl the ends of the strips will have square edges. If desired however, the corners of the connecting portions may be founded. The resistor shown in Fig. 5 is somewhat more compact than that shown in Fig. 2.

In Fig. 7, I have shown the manner in which a plurality of resistors such as that shown in Fig. 2 or 5may be employed as resistance units to form a resistor of large! capacity. For connecting the several units together, I provide rods 60 which extend through openings 61 shown in Figs. 2 and 6, located in the sides of the channel bars 21 other when heated to high temperatures by the electric current passing therethrough. This construction of the conducting strips eliminates short circuiting of the resistance element at high temperature.

I claim 1. The method of forming a resistor having a resistance element formed from a sheet of metal, having slits therein which divide the sheet into a series of strips and two rows of substantially flat connecting portions at the ends of the strips, the connecting portions at opposite ends of a strip respectively joining said strip to strips at opposite sides of said strip, which method conslsts in twisting the strips in such amanner that the connecting portions lie in parallel planes with the connecting portions of each row, spaced from one another and in aligmnent, and so.- curing said connecting portions so spaced to twoparallel supports. 7

2. The method of forming a resistor having a resistance element formed from a sheet of metal having slits therein which divide the sheet into a series of strips and two rows of connecting portions at the outer ends of the strips, the connecting portions at opposite ends of a strip respectively joining said strip to strips at opposite sides of said strip which method consists in twisting the strips in such a manner that the connecting portions of each row are spaced from one another in a direction normal to their faces, and all the connectingportions of each row are in alignment, and in mounting the said resistance element on a support which mainsite ends of a strip respectivelyjoiningsaid strip to strips at opposlte sides of said strip, which method consists in twisting each of the strips through a half turn so that the connecting portions of each row are spaced from one another in a direction normal to their faces, and all the connecting portions of each row are in alignment, and in mounting the said resistance element so formed on site sides ofa strip respectively joining thesaid strip to strips at opposite sides of said strip and each of the connecting portions having an opening therethrough, which method consists in twisting the strips so that the connecting portions of each row are spaced from one another and the axes of t eir openings are in alignment, and in mounting said resistance element so formed on two parallel rods extending thro'ugh.;said

openings.

5. The method of forming a resistor having a resistance element formed from a sheet of metal having slits therein, which divide the sheet into a series of strips and two rows of connecting portions at the outer ends of strips, the connecting portions at opposite sides of astrip respectively joining the said strip to strips at opposite sides of said strip and each of the connecting portions having an opening therethrough in line with the slits which consists in twisting each of the strips through a half turn so that the connecting portions of each row are spaced from one another and the axes of their openings are in alignment, and in mounting said resistance element so formed on two parallel rods extending through said openings.

6. The method of forming a resistor having ,a resistance element formed from a sheet of metal having slits therein which divide the.

sheet into a series of strips and two rows of connecting portions at the outerends of the strips, the connecting portions at opposite ends of a strip respectively joining the said strip to strips at opposite sides of said strip, which method consists in twisting the strips a half turn and supporting the con.-

7. The method of forming a resistor having a resistance element formed from a sheet of metal having slits therein which divide the sheet into a series of strips and two rows of connecting portions at the outer ends of the strips, the connecting portions at opposite ends'of a strip respectively joining the said strip to strips at opposite sides of said strip, which method consists in twisting the strips substantially throughout the length of the strips and bringing each of the connecting portions in planes parallel to each other, andv supporting each of the connecting portions at therespective ends of the strips in alignment. A

8. .A continuous resistance element of slitted sheet metal, said element having a zigzag form and comprising strips and connecting portions at the outer ends of the strips, the connecting portions along each side of the element being fiat and facing one another in alignment and the strips being twisted.

9. A resistor comprising a continuous resistance element of slitted sheet metal, said element having a zigzag form and comprising strips and connecting portions at the outer ends .of the strips, each of said connecting portions having an opening therein in line with the slits, the metal of said strips being twisted so that the connecting portions along each end of the strips face one another and are spaced from one'another and the axes of their openings are in alignment, and supporting means extending through said openings.

10. A resistor comprising a continuous resistance element of slitted sheet metal, said element having a zigzag form and comprising strips and connecting portions at the outer ends of the strips, each of said connecting portions having an opening therein, said strips being twisted .so that the connecting portions along each edge of the element are spaced from one another and the axes of their openings are in alignment, an insulated supporting rod extending through the open"- ings at one edge of said element and a second insulated supporting rod, parallel to' said first named rod, extending through the openings at the other edge of said element.

HENRY T. HAYDEN, J R.

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