US2945198A - Electrical resistor - Google Patents

Description

July l2, 1960 M. E. BoURNs 2,945,198

. ELECTRICALl RESISTOR Original Filed July 5, 1955 .frai /ff 34 l INVENTOR. 7i 24J MAQM/ E. 50am/s y 5i [70 52 BY jira; 6I v United StatCS Patent O ELECTRICAL RESISTOR Marlan E. Bourns, Riverside, Calif.

Original application '.luly 5, 1955, Ser. No. 519,847. and this application Sept. 14, 1959, Ser. No.

3 Claims. (Cl. BSS-d150) The present invention relates to new and improved electrical components and is a division of my pending application, Serial No. 519,847, filed July 5, 1955, entitled Electrical Resistor (as amended by examiner), now abandoned. More specifically, it relates to new and improved electrical potentiometers and like devices.

A Agreat many organizations at the present time are devoting considerable time and money to the development of various electrical or electronic devices which consist primarily of a number of separate electrical components secured together in a compact assembly,` capable of being used as an integral unit in a large device, such as for example, a computer or'the like. vOne particular effort along these lines has been' inancedto a large ex-v tent by -the United .States Air Force and is commonly termed Project Tinker Toy. In thisTinker Toy project, the electrical componentsutilized are in the form of small `ilat squares approximately 3%; of an inch in length along each .edge and of varying thickness. Each of the components in this type of a structure is secured within an elongated cage consisting of 12 Wires, three of which are disposed along each edge of each component. All of the wires used are located parallel to one another. times, less than twelve wires are employed, and discontinuous wires are employed in order to make or complete a desired electrical circuit.

As nearly as is known at the present time, no potentiometers or like electrical components of essentially an adjustable nature have been developed which are capable of being used satisfactorily in the so-called Tinker Toy project. It is a broad object of this invention to` provide adjustable potentiometers and resistors which can be satisfactorily utilized in the so-called Tinker Toy type of construction. Another object of the instant invention is to provide adjustable electrical componentsnof the class described which are capable of wide use inv other diverse applications and which may be easily manufactured with aiminimum of difficulty. A Ifurther'object of this invention is to provide small electrical components of the category indicated which `are rugged so that they are c-a`- pable of standing a large amount ofabuse. Another object of this disclosureis toteachgthe/v manufacture and construction of potentiometers and the like which may be directly secured to various wires in an `electrical circuit, and which may bersupported in a desired position by these wires. y

Further objects of this disclosure as well as many other advantages of the constructions described herein will be vapparent from the remainder of this description, .includ- ICC Fig. 4 is an isometric view of a member utilized in the potentiometer shown in Fig. 1; n

Fig. 5 is a view similar to Fig. 3 of a modied potentiometer of the invention;

Fig. 6 is a cross sectional View taken at line 6 6 of.

Fig. 5;

Fig. 7 is a side view of a second modified potentiometer of the invention;

Fig. 8 is a cross sectional view taken at line 8-8 of Fig. 7; and

Fig. 9 is a cross sectional view taken at line 9-9 of Fig.,8.

lt is to be understood that the accompanying dra ings are not scaled to any precise commercial unit but are designed merely to illustrate the essential, preferred features of the present invention. Wherever convenient for purposes of illustration and explanation, like numerals have been utilized to designate like parts.

The present invention is defined in detail by the appended claims forming a part of the specification. If desired, however, the present invention may be briefly summarized `as required by the Rules of Practice of the United States Patent Oce as being primarily concerned with new and improved electrical instruments or components which include: 4a housing; means defining a disc shaped' cavity within said housing; rst and second electrical means disposed within said cavity; a movable member located within said cavity; means for rotating said movable member within said cavity, said means projecting to the exterior of said housing and being located at one side of said cavity; means attached to said movable member for electrically connecting said rst and second electric-al means; and means -for connecting said first and second electrical means into an electrical circuit, said means being electrically connected to said irst and second electrical means and projecting to the exterior of said housing.

The details of the invention are best explained directly by reference to the `accompanying drawings. In Figs. 1 -through 3 of the drawings there vis shown an adjustable potentiometer 10` of the invention which includes a base 12 and a cover 14 positioned upon this base. lt is to be noted that both the base 12 and the cover 14 are of roughly the same exterior shape as -a small square wafer and that the exterior dimensions of the cover 14 are smaller than the exterior dimensions of the base 12 so that part of the upper surface 16 of the base 12 is exposed when the cover is located on it. The base 12 and the cover 14 are preferably formed out of a non-conductive material such as, `for example, a suitable phenolic material'or a dielectric ceramic. These two members are put together by suitable conventional means such as, forexample, `an adhesive, so as to deiine an internal cavity 18 of disc like shape between them. Y i

The upper surface 16 of th'e base 1'2 is of atconfiguration and includes an arcuate resistance strip 20 formed out of appropriate conventionalmaterial such ing the appended claims and the accompanying drawings,

as, for example, a resistance ink.v The ends of this resistance strip are overlaid by parts of terminals 22 and 24. These terminals are preferably formed of a silver ink 0r the like and extend from the resistance strip 20 to adjacent edges 26 of the base 12 so that they may be readily connected to various Wires or other means used to electrically connect the potentiometer 10 into a circuit. Within the center of the arcuate resistance strip 20 there is located upon the upper surface 16 a circular end 28 of a terminal 30 an electrical return which is similar to the terminals 22 and 24 and which projects to adjacent o edge 26 of the base 12. I

Disposed along the edges 26 of the base 12 and edges 32 of the cover 14 are a series of grooves 34 which are Patented July 12,1960 j specifically designed to hold the various wires such as, for ean'iple, wires employed in the so-called Tinker Toy type of construction when thqpotentiometer 10 is mountedsnf this type eil-eil.v aesemblxf; With.. this epeefreetsn the various terminals 22, 24, andA 359 may be secured1 di; reetlyte., these Wires by eelder er ether] like mee l desired so that as a double headed, screw 36 disposedl withina-,Islot'ii Within the cover. 1 4, istnrneda disc4 40 located within the cavity 18 is turned, placing resul `rit contaots; 42y and. 4,4: in engagement with. dilieraent portions of the resistance strip 20 and with the sainel portion of the circular endI 28.l at the terminal 34, This construction is best understood with reference to ligs. 3 and 4 etliedteuinge- The screw 36 is provided with grooves 46 whichl are designed. te be engaged, byy preieetioee, 4fl fermed une th do er-14 within the slot, 3'8, so as to' hold this screw in, position with the threads Sli, on it projecting ashort distance through, an openingf 52. inY the` cover 14 f connecting` the. slotv 38 and the cavity 18. Thus, with` this construction the threads 5t)A areV located within the cover 14 as to engage with what are in effect gear teeth 54 formed on. thef peripheryl of the disc 40. Ihe contacts 4 2, and, 4,4I are formedv out of the disc 40 by 'aV simpleV punching operationy so, as to include ends I56A and 58, respectively,`which are designed to engage the resistancel stripl Z0 and the. circular end Z8. The disc 40 is prefc raljlvlyY formed out of a comparatively strong resilient metal such as, for example, brass, by, a simple I netal st Lping operation, and isof such a dimension as to tit cl =ely4 within the cavity 18. The4 contact 44,y normally holds this disc 40 in a desired position withinv the cavity llparallel tothe surface 16. The screw 36 is preferably f ogrncd out of such non-conductive materials as nylon or the like, and is located at the side of the cavity 18.

In' Eig. 5`v of the drawings a Inodilied potentiometer 6i) oli the invention is shown which .diers from the poten-j tiongeter solely in that thev disc 40 .previously describedl isl replaced byY ad ring. 6,2 having gear teeth 6 4 such asV the teeth 54 formed on the outer periphery thereof., thisv is held a resilient metal contact ring 66 of partially circular shape having formed thereon. resilienc contact arms 68, and 70 engaging thel resistance strip 2 0 and the circular end 2.8!. With this construction the contact ringn 66 is preferably. larger than 18Q `of a circle, so that it mayv be easily held in positiony within.r ring 62v by Spring tension.V Igf desired, the contact ning 6 6 may be secured to the ring 62 by. the use of rivets.. er an adhesive- The ring 62, may be femed, either out of metal or of a non;conductivev material such,l as, for example, phenolic resin. In the latter preferred casev it is possible to form the screw 36, shown in this igureout of metal.

Those skilled in the. art Will realize that all of the parts of the potentiometer 60E which are the saine as the various parts of the potentiometer 10, preillioluslyy described are identified in Eigs. 5 and ,6: of the drawings by primes of the same numerals used earlier vin this description.

In Figs. 7, 8, and 9 of the drawings a second modilied potentiometer of the invention 7'2 is illustrated which includes a base 74, a spacer 76 anda cover 78.-A All Vof these three members are preferably formed out of a noni conductive material such as, for example, a ceramicv or a phenolic resin in such a manner that the edges Sil, of the spacer 76 are shorter than the edges 8,2 of the base 74 and the cover 78. Appropriateigrooves or notches. S4, `similar to the grooves 3,4 previously described, are provided in the edges 80 and 82 for the saine PUPQSC. aS. the grooves :34. The base 74, spacer 76 and theV cover 78 may be attached to one another in anyfconvenicnt manner such as, for example, through the use Vof an adi hesive or the use of rivets so as to form a composite sandwich-like construction as illustrated,A 'i

Withln the spacer 76 there is located a Grlllal 0pm' agentes ing 86 which in the sandwich-like construction serves to `define together with the base 74 and the cover 78a cavity 88 such as the cavity 18 previously described. On the top surface 90 of the base 74 there is provided a resistance strip 20 similar to the resistance strip 20 and terminals 22 and 24 similar to the terminals 22 and 24 previously described, and all` terminal 30' similar to the terminal 30 previously, described,l 'lhis latter terminal e. pia. 10.2 leeeted. within. aligned helee (Het, ehewnl in he base 74` andtllecover 78f`so as lto be held normally f @fl 412011 the gear Y19.0, een efeget withj geef'feeif 10,3. formed,` on ythe periphery of, the disc 98 Aand so that the'gear A1,04) is atV one side ofthe cavity 8,8. IContzvct's 111,9 and. 11,2. gie femied, eil, thediee in e Similar maener tefthe.V 'mnner in. Whiehhe eeete'elfe 42. and. 44. are fortned oni, the 4t)l inorder to engage the .resistance SIRZQ.' @lidi-tch@ @11d 9.3i O f. ih@ 'terminal 3,0' employed;

The'eleetrieel eenduetieumeene enueleuedl en. the bese 74' Ihose skilled Yin, 'the'art' lwill realizeV beth the mesied, peteritiometers 60 and 7,2 een be eenneeted te Yerieuef` wire essentially the sante manner. asfthe potentiom eter 10, A11 f theee'threei different constructions are quite dvantageeus nasmeeh as'with there quite iie ad# iletment is., possible. threughfthe', eee ef. what amounts, te. geary reduction rneans'formed on the'discs '40, 4Q', and 9.15 ad en the, eer-ene 3,6, 3.6"ans1 en'. the gearv 100 V These ensttuetiens are quite advantageous fier assembly ihf complex electrical assemblies such4 as those of ythese#H lled Tinker Toy project inasmuch as the means ueed'ie, ad' their are relatively lsmall andare located in such a er as not to, interfere to any materialextent with the i Quiete/rs 110, dd and 72 are very thin, small devices which are quite reliable in use and whieh. can. be quite easilyy eesetreetefl utiliziegeetabliehed techniques- QbYOuSlY nigmber'ei Changes may be made in this invention without departing froml theV essential featuresy Qt it, AS,` an exampleef. Sueh changes, the Sandwich type of ,eeaetraetien illustrated in Figs- V 7, 8, and 9 ef the dra 93S. CQuld be uilized'iri forming the Potentiometere" l d 69, Further, the ring type ofconstruction shown in. Elgf 4, ef, the drawings mai/"be utilized together with a Small, drive gee! Such. as the'gear 1.00- All Suele'"modifE tications of this, category are considered to be'pafrt of the present in tion insofar as theye'arc defined vinthe api Pended 1claims. lelgieg 1,. A new and` improved potentiometer which includes: a hase; a cover positioned upon said base, saidY cover in elediag gel greening, ferme@ therein Se 'afs te. define' an ine israel eaYfY means defining first aligned lielele, Aiffeeil cover and said base; a pin positioned within said holes; metal dise having gear teeth formed on the cuter periphery thereof secured to said pin within said cavity; -an arcuate resistance element positioned Within said cavity; an electrical return positioned within said cav,- ity; Yterminal means connected to said resistance element and said electrical return, contact means secured to said ymetal disc so as to engagek said resistance elementand said electrical return; means defining secondv aligned holes in said cover and said base; a second opening formed in said spacer vadjacent to said lirst opening and said second aligned holes; a second pin positioned within said secoii'd an openingjl'o in thek spacer '7.6 so that the teeth complete assembly. Further, alliof the, potentie holes; and a gear mounted on said second pin so as to engage said gear teeth on said metal disc.

2. A new and improved potentiometer which includes: a base; a spacer positioned upon said base; a cover positioned upon said spacer; irst opening formed within said spacer so as to define within said potentiometer an internal cavity of disc-like shape; means definingv iirst aligned holes in said cover and said base; a pin positioned within said first holes; a metal disc having gear teeth formed on the outer periphery thereof secured to said pin within said cavity; `an arcuate resistance element positioned Within said cavity; an electrical return positioned within said cavity; terminal means connected to said resistance element and said electrical return; contact means secured to said metal disc so as to engage said resistance element and said electrical return; means defining second aligned holes in said cover and said base; a second opening formed in said spacer adjacent to said first opening and said second aligned holes; a second pin positioned within said second holes; and a gear mounted on said second pin so as to engage said gear teeth on said metal disc.

3. A new and improved potentiometer which includes: a base; a cover positioned upon said base, said cover including an opening formed therein so as to define an in ternal cavity; means defining first aligned holes in said cover and said base; a pin positioned within said rst holes; a metal disc secured to said pin within said cavity; an arcuate resistance element positioned Within said cav ity; an electrical return positioned within said cavity; terminal means connected to said resistance element and said electrical return, Contact means secured to said metal disc so as to engage said resistance element and said electrical return; means dening second aligned holes in said cover and said base; a second opening formed in said spacer adjacent to said rst opening and said second aligned holes; a second pin positioned within said second holes; and a gear mounted on said second pin so as to engage said metal disc.

References Cited in the le of this patent UNITED STATES PATENTS 586,864 Pieper July 20, 1897 2,197,312 Nelson Apr. 16, 1940 2,451,241 Rosentreter Oct. 12, 1948 2,514,682 Tellkamp July 11, 1950

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