US2627008A

US2627008A - Multiple tap resistance unit and the method of making the same

Info

Publication number: US2627008A
Application number: US233385A
Authority: US
Inventors: Dunlop James
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-06-25
Filing date: 1951-06-25
Publication date: 1953-01-27
Anticipated expiration: 1970-01-27

Description

Jan. 27, 1953 UNLOP 2,627,008

J; 'D MULTIPLE TAP RESISTANCE UNIT AND THE METHOD OF MAKING THE SAME Filed June 25, 1951 1FIG.I

F'IG.3

INVENTOR. JAM ES DU N LO P ATTORN EY.

Patented Jan. 27, 1953 UNI TED STATES PAT ENT OFFICE '-=2,s27,00s Mcn'iIPLEflrARnEs N E ii i-T ND METHOD OF MAKING THE SAME James Dunlap, Philadelp'hia,-Pa. "Application June 25, 1951, 'Seria I No. asses claims.

This invention relates to rnultiple" tap resistance' units, and the 'rnethod of making the'sa'me, which unitsare used, in various electrical instruments and apparatus, to provide resistance which may be varied step by stepin the use of the devices of which such resistance units form a part.

The principal objector the present invention is to provide a multiple tap resistance unit which will be simple in construction, relatively inexpensive to manufacture, and which will be durable in use so that there will be littlelikelihood of damage to the delicate parts even though'said units may be more or less roughly used.

The nature and characteristic features of the invention will be more readily understood from the following description, taken in connection with the'accompanying drawing forming-part hereof, in which: 7 v

Figure 1 is a side elevation, somewhat enlarged, of a resistance unit embodying the main features of the present invention, the same being shown in an intermediate stage of its construction;

Fig. 2 is a transverse section taken approximatelyon' the "line 2-2 of Fig. 1, still further enlarged;

Fig. 3 is a sectional viewillustrating a form of the invention in which the resistance coils are of a non-inductive character; and

Fig. 4 is a view illustrating a, resistance unit embodying the main features of the present invention shaped for mounting in a particular form of electrical device.

It should, of course, be understood that the description and drawing herein are illustrative merely, and that various modifications and changes may be made in the structure and method disclosed without departing from the spirit of the invention.

The invention will be best understood by first referring to the method of making a typical unit embodying said invention. A strip H) of insulating material of the proper characteristics is employed in the making of the unit. Various materials will be found adaptable for this purpose, but the preferred material consists of nylon in strip form, the strip being of the requisite width and thickness.

At spaced intervals along the strip, circular discs of the material are punched out, which leaves the strip ID with a series of spaced holes II. The punchings, that is the discs which are cut out of the strip, are then machined into the form of miniature spools I2, shown in cross-section in Fig. 2 of the drawing, upon which the resistance wire 13 is wound.

'2 'wnenfuoweven the resistance coils 'musttbe of anon-inductive character, then the spools l2 -shown in'Fig.'3 of the drawing may beused, each providing two annular compartments, in one of which thewinding I4 is reversed indirection-with respecttothe other winding 1 5.

After the miniature spools [2 have been'woiind, the same are replaced in the openings H which were left in thestrips '10 "when. the discs, from which'"the spools l2 were "madefwera'pu'nched from the strip.

The tap"wires l6 extend 'transve'rsely with respect to the strip 10. Each ofsaid wires 1 8 passes from one face of the strip [0 to the otherthrough a ertures 11 provided for that purpose, and one end' [8 of each tap wire is b'entaroundthe lower margin of the strip. Theoth'er'end'of'each'wire "in the strip [0, the'lead-inwires 20 for the several coils which are mounted on the spools i2 are connected thereto, preferably by soldering. The strip ID, with the spools and wires mounted therein as aforesaid, is then coated by dipping or spraying. The coating 25 preferably being of a suitable synthetic resinous material which will serve to encase the strip and the spools mounted therein in a protective coating. This coating will also serve to seal the various crevices, interstices, and openings against the entrance of moisture or other deleterious materials, whether the same be of a gaseous, liquid, or dust like character.

After the strip with the spools mounted therein has been coated as aforesaid, the strip may then be bent to any desired shape, as for example, in the circular form as shown in Fig. 4 of the drawing. When the strip is thus bent the spools upon which the resistance wire is wound will be held in place in the strip by the coating 25, and will be constrained to follow the curvature when the strip is so shaped.

By the foregoing arrangement there is provided a simple, convenient, and relatively inexpensive form of resistance unit, which has been found to be quite practical and exceedingly useful in various applications in electrical devices, instruments and apparatus.

I claim:

1. A multiple tap resistance unit comprising a strip of insulating material having a plurality of spaced holes, spools mounted within and filling said holes, said spools being made of the same material as the strip, and resistance wire wound on said spools.

2. A multiple tap resistance unit comprising a strip of insulating material having a plurality of spaced holes, spools mounted within and filling said holes, said spools being made of the same material as the strip, resistance wire wound on said spools, and a protective coating on the assembled structure.

3. A multiple tap resistance unit comprising a strip of insulating material having a plurality of spaced holes, spools mounted in and filling said holes made of the same material as the strip, resistance wire wound on said spools, the tap .wires to which lead-in wires of the spool Windings are connected secured to the strip and extending therefrom at places between the spools.

4. A multiple tap resistance unit comprising a strip of insulating material having a plurality of spaced holes, spools mounted in and filling said holes made of the same material as the strip, resistance wire wound on said spools, the flange portions of said spools being notched for the passage therethrough of lead-in wires extending to the windings on said spools, tap wires to which said lead-in wires are connected secured to the strip and extending therefrom at places between the spools.

5. A multiple tap resistance unit comprising a strip of insulating material having a plurality of spaced holes, spools mounted in and filling said holes made of the same material as the strip, resistance wire wound on said spools, the flange portions of said spools being notched for the passage therethrough of lead-in wires extending to the windings on said spools, tap wires to which said lead-in wires are connected secured to the strip and extending therefrom at places between the spools, and a protective coating on the assembled structure.

6. The method of making a multiple tap resistance unit which consists in cutting a series of spaced holes in a piece of insulating material,

4 making spools to fit Within said holes, winding resistance wire on said spools, and then placing the spools within the holes to fill the same.

7. The method of making a multiple tap resistance unit which consists in cutting a series of spaced holes in a piece of insulating material, making spools to fit within said holes, winding resistance wire on said spools, then placing the spools within the holes to fill the same, and coating the assembled structure with a layer of protective and sealing material.

8. The method of making a, multiple tap resistance unit which consists in punching a series of spaced holes in a strip of insulating material, utilizing the punchings from the strip to make spools, winding resistance wire on said spools, then replacing the spools in the holes in the strip, mounting a series of tap wires on the strip at places between the spools, and connecting the spool windings to the tap wires.

9. The method of making a multiple tap resistance unit which consists in punching a series of spaced holes in a strip of insulating material,

utilizing the punchings from the strip tomake spools, winding resistance wire on said spools, then replacing the spools in the holes in the strip, and coating the assembled structure with a layer of protective and sealing material.

10. The method of making a multiple tap resistance unit which consists in punching a series of spaced holes in a strip of insulating material, utilizing the punchings from the strip to-make spools, winding resistance wire on said spools, then replacing the spools in the holes in the strip, mounting a series of tap wires on the strip at places between the spools, connecting the spool windings to the tap wires, and coating the assembled structure with a layer of protective and sealing material.

JAMES DUNLOP.

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

UNITED STATES PATENTS Name Date