US1646535A - Resistance element - Google Patents

Description

Oct. 25, 1927. 1,646,535

c. HoRToN RESISTANCE ELEMENT Filed Ju1y14, 19,25

Patented Oct. 25, 1927.

-UNITED STATES CHARLES HORTON,

OF RIDGEFIELD PARK, NEW JERSEY, ASSIGNOR T0 THE PILOT ELECTRIC MANUFACTURING COMPANY, INC., 0F BROOKLYN, NEW YORK, A COR- PORATION 0F NEW YORK.

RESISTANCE ELEMENT.

Application 'led July 14, 1925. Serial No. 43,622.

This invention relates to improvements in resistance elements more particularly-,to vplate and grid resistances applied in radio reception devices. Upto the present date, these resistance elements usually'consist of metallic or impregnated resistance units en purpose of this invention to provide a simle resistance element of exceedingly low `cost and capable .of quantity production with a minimum of mechanical operations. The resistance element itself consists of a fibrous material vparticularly Ithat having fibers in closerelation to one another whichl element is thoroughly impregnated with a liquid having fairly high conductivity whereby current may pass through the precipitant consisting of the impregnated material, subject of course to the resistance of the impregnated material.

In general it is aimed to so enclose this fibrous resistance element so as to make the same impervious to atmospheric conditions and provide a sealed resistance element capable of retaining its constant value. AThe main object of the invention is to provide a simple and yetl effective resistance element for radioy circuits, which element consists of va minimum ofparts easily produced and efficient in operation and cheap in production cost.

This invention in general contemplates the application of a phenolic condensation product or other insulating materialcapable of being molded, Wherewith to surround and completely seal the resistance element and at the same time to cooperate with the resistance in the molding operation so as to provide for a constant value of resistance thereof.

Among the objects of the invention it is aimed to provide a fibrous conducting element applied as the resistance member in a radio circuit, which enclosed in an insulating medium3to provide a simple and yet constant resistance by p means of an impregnated or fibrous coated element is completely4 material; to enclose the resistance element 1n a seal-tight casing formed ofinsulation material which material during the process of molding, Whether it be by heat treatment or cold molding, will compress the resistance element to form a uniform product; to provide av definitely ascertained resistance element consisting of two/cooperating members, one of which serves asthe fastening. means, and and the other of which is the resistance element itself consisting of an impregnated fibrous material enclosed together with the bindingposts or fastening means in a shell of insulated material; andlastly, t'o generally provide a simple resistance element-for 4use in radio circuits, which element has a constant value, vis simple in structure and possesses a high efficiency and low production cost. Y

Specifically closed ori sealed non-metalliciimpregnated material as a resistance element in a radio reception device.

Still further it is aimed to fibrous material impregnated with a Conducting liquid having readily drying properties to serve as 'a resistance element, which fibrous material is molded Within a sheet of insulation material.

Still further it is aimed to provide an element, readily produced in quantities, brous material-'impregnated in a conducting solution, which element can be controlled as. to its resistivity by the varying of the thickness and length of the same, and which is further encased in an insulation support.

Still further it is aimed to provide a process wherein a sheet of impregnated material is positioned between metallic fastening means all of which are encased in an insulation medium which servessto compress the of fi at the same time a binding post,

provide a resistance element with respect to its thicknessand' atthe same time form a seal for. protecting. the same from variations due to atmospheric conditions,

Still further it is aimed to provide a simple process consisting of five steps; that of 1, impregnating the sheet of fibrous material; 2, cutting blanks of the same slightly thicker than 'the required thickness of the 'roduct; 3, positioning conductor terminals at the extremities of the impregnated blanks I and features of the invention and molding the same within a shell of insulating material such as a phenolic condensation product, which molding operation causes the blank material to be compressed and the thickness of the same to be decreased and finishing the complete product..

These and other advantages, capabilities will appear from the subjoined detailed description of one specific embodiment of the invention as illustrated in the accompanying drawings in which, v Fig. 1 represents a plan view of the element forming the subject matter of this invention. l

Fig. 2 is a side elevation of the same.

Fig. -3 is a side elevation in section showingy the element before molding in conjunction with the posts of the same. Fig. 4 is a section 'end view, looking along lines 4 4 o f Fig. 3 and showing the central portion of the element in section.`

Fig. 5 is a side elevation in section show.- ing element imbedded in the lmolding ma terial. Fig. 6 isan end view of section along lines 6 6 of Fig. 5, showing the element imbed- `ded in the insulator.

Fig. 7 is a side elevation in section of a modification of the structure shown in Fig. 5. Fig. 8 is a cross section along lines 8--8 vof Fig. 7

Referring particularly to the reference characters in the drawing; numeral 1 represents sheet or length of fiexible fibrous material which material is cut out in the form of blanks in any predetermined .thickness required depending upon the resistance required in the radio circuit. This sheet 0f flexible material as shown in Fig. l is out in one of its .preferred shapes'though it is well within the province of the inventor to vary'the length and thickness without departing from the scope of thev disclosure.

This flexible sheet which may be 'of parchment or any material of fibrous nature haw ing its constituent fibrous lengths close toether, is coatedwith a liquid having a air-ly high conductivity, that is, the fibrous sheet is immersed and impregnated Vwith a solution which after evaporation, deposits materials or constituents of conductive properties when dried. This impregnation may be carried out in a single step or by means of a multiple dipping operation, it being the object of this in vention to provide a substantially fibrous-material .capable of conducting electricity due to the conductive material introduced therein by the adhesion of the deposited particles from the coating solution, tothe closely constituted fibers forming the sheet.

Though various materials may serve as the impregnating solutionit is preferredby the applicant to provide a hquid containing carbon particles which liquid dries up rapidly and leaves a substantial carbon deposit in the interstices of the fibers upon the evaporation of the solvent contained in the liquid.

Referring to the Figs. l and 3, it is observed that the end extremities ofthe sheet haveattached thereto bushings 2 and 2 which bushings havea 4base 3, consisting of a disc-like surfcace and an upwardlyl extending projection 4, which projection is adapted to pass through the apertures 5 formed in the sheet of 'fibrous material by the stamping operation. erably of copper or brass or any other conducting material. These bushings have openings 6, in the central portion thereof," by means of which openings contact may bc formed with the remainder of the elements in the radiorcircuit to which this invention is applied. In this manner the bushings form a positive terminal for connection with The bushings-are formed prefthe other elements in a radio circuit so that l the resistance element in the form of im? pregnated sheet is readily connected either in the grid or plate circuits as desired when adopted for either grid orplate resistance use. f

It should be noted thatthe sheet l of the flexible thickness, that is, at least twice that or more of that of its final thickness before it is compressed by means of surrounding coating or.

.seal of insulating material which in this case and subjected to pressure whereupon a completecoating 7 is formed around the flexible material 1, and at the same time about the bushings 2 and 2', this coating of insulating material being adapted to completely enclose and'. surround the flexible sheet of fibrous material l, and the` bushing with the exception of the tops of the upper portions and lower portions 8 and 9 of the bushings and the central aperture 6 which are 'ex-A posed'so as to form metallic contacts with the remainin elements of aradio reception device in which this. invention is applicable.

fibrous material is of considerable v It should be noted in Fig. 6 that the thickness of the sheet of fibrous material 1, is considerably decreased with respect to that of thickness as before -molded which phenomenon, as above stated, is due to the application of pressure during the molding operation. y

In Figs.' 7 and 8 are shown modifications of the invention wherein a plurality of of fibrous ,material 10 and 11, are place between Washers 12 and 13, at which extremity thereof and 4through which washers there is passed an eyelet 14, protruding beyond extremities thereof. -When subjected to the molding operation, w1t preferably a phenolic condensation product or other moldable materials, the eyelet 14, due to pressure to whichl it is subjected by the dies in thev molding operation, compresses the washers 12 and 13 while at the same time the respective sheets 10 and 11 are compressed so that the finished product is practically similar to that shown in Figs. 5 and 6 with the exception of the fact that a plurality' of compressed resistance materials 10 and 11 are` contained within the insulated material forming a seal for the same. The 'eyelet 14: and 14 similarly vto the bushings 2 and 2 form contact terminals for connection with of the elements in a radiocircuit when the nolded product is properly finished off.

feature closely interwoven fibers.-

rial which 4conducting Though the element herein shown may be preferably madeof flexible material, it is within the province of the inventor to use among others cardboard, stie'ned or fiexible cloth or any stiff or flexible fibrous material or any other material having as 'its main All these materials, or those of fibrous nature, can readily be impregnated witha liquid containinga finely' divided conducting matematerial will remain within the interstices of the fibers of 4the material after the evaporation of the solvent which metallic or conductive material is so distributed as to form a positive resistance element of readily determinable ,resistivity value. These materials are readily encase within the insulating material by molding,

whether it be hot or cold, it being the pur' pose of the inventor to provide acompletely d length of the this assembly is h modifications may be made to the details of impregnated fibrous the remainder enclosed resistance element constant in value and unaffected by external conditions.

The resistance of these elements is controllable by the thickness of the sheet, the sheet and the quantity of mate'- rial Vdeposited therein by impregnation, all of which degree of accuracy.

It is obvious vthat the various changes and construction without departing from the general the appended claims.

What I claim is:

1'. A resistance element for radio reception devices comprising a fibrous element impregnated with conducting material, apertures at opposing extremities of said .fibrous element, washers having central apertures disposed on opposite sides of said yfibrous element and pressing against the same at points adjacent the., apertures thereon, eyelets passing through the apertures in the washers and the fibrous element and bent over at their extremities thereby to maintain vthe washers in fixed position 'with respect to the fibrous element, and surrounding said fibrous element and said washers, the inner surface of v said eyelet means ,being adapted`to f orm contact 'with the remainder of the devlce.

2. A resistance element for radio reception devices comprising a plurality of impregnated fibrous conducting elements, apertures at opposing extremities of said elements. washers disposed adjacent said apertures on opposite sides of `the fibrous elements and eyelet members positioned within said ap'ertures serving .to press against the washer members, whereby to clamp the conducting elements, and aninsulating medium surrounding and imbedding' the fibrous elements and said washers, whereby contactwith the d remainder of a radio device is made through the eyelet members.

CHARLES HORTON.

factors are controllable to a high spirit of the invention set forth in -l

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