US2031211A - Electrical resistance device - Google Patents
Electrical resistance device Download PDFInfo
- Publication number
- US2031211A US2031211A US621609A US62160932A US2031211A US 2031211 A US2031211 A US 2031211A US 621609 A US621609 A US 621609A US 62160932 A US62160932 A US 62160932A US 2031211 A US2031211 A US 2031211A
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- United States
- Prior art keywords
- resistor
- contact
- case
- strip
- contact member
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01C—RESISTORS
- H01C10/00—Adjustable resistors
- H01C10/30—Adjustable resistors the contact sliding along resistive element
- H01C10/32—Adjustable resistors the contact sliding along resistive element the contact moving in an arcuate path
Definitions
- a flexible contact member' which is electrically independent of the resistance element at all times except at one point which may be optionally varied throughout the entire range of said element.
- an object is to provide a resistance element of cylindrical' shape havingv theexposed surface of the resistance element in-. wardly presented and opposed by a flexible member which is maintained normally in insulated and spaced relation and which is capable of being variably contacted with the exposed surface, said 4parts having a novel arrangement which facilitates the connections thereof with the required terminals.
- Another object is to provide a novel flexible contact member for a resistance element of this nature.
- Figure 1 is anopen face view of a device em ⁇ bodying the features of the invention.
- m. 2 is a sectional view through o. portion of ⁇ the device taken as indicated by the line 2-2 of Fig. 3, parts being broken away to clarify the muon.
- Fig. 3 is a central section through the device on the line 8 3 of Pig. 1.
- m. 4 is nii-elevation or tno inferior of uio aovioe looking at the terminal assembly
- Fig. 5 is a fragmentary sectional view on an enlarged scale taken through one side of the device.
- Il desig- I nates generally an enclosing case or which is preferably formed of sheet metal Aor economy inv manufacture.
- the case is; cup-shaped and .comprises a base I I and a substantially cylindrical 15
- a further object resides in the provision of such side wall I2. defining an open face which is normally closed by a suitable cover I2* (Eig. 3) which f is heldin place by tabs Il. 'Ihe base is apertured as at Il (Fig. 4) vto receive a bushing il (Fig.
- Adiacent the inner surface of the side wall i2 is a sheet I! of any suitable insulating material, which preferably covers the entire wall surface.
- a fiat annular ring or washer Il also of insulating material, covers a substantial portion of the 30 base of the case inwardly of said wall.
- is disposed concentrically and interiorlyofY the sheet of insulating material Il but does not extend completely through the'length of the inner periphery 35 of the While'any suitable type of resistor y v .may be employed. that which is preferred comf prises a smooth surface resistor element!! (Fig.
- a preferred fonn of con tact member comprises imelongated strip 24 -cf 50 thin, nexible.- current conducting material. such asbronae,whichstripisdisposedwithinandadiacenttotheexpcsedsinfacecf tllereaistorele- ⁇ ment l2.
- the flexible strip 24 is preferably maintained as in definitely spaced and concentric relationship to the resistor element in the following manner (see Fig. 6). From one side of the strip relatively narrow webs 2l extend, each of which terminates in a ilat plate 28.
- the strip 24, webs 25 and plates 28 are dimensioned so that. by bending the webs along a longitudinal line, generally indicated by the line A-A in Fig. 6, adjacent the plates, a structure of generally U-shaped cross section may be obtained which will flt about or straddle the inner side edge of the resistor 2
- the strip 24 may be maintained in deflnitely spaced relationship to the resistor element 22 by means of the webs and plates which are bound between the resistor 2
- the plates 26 preferably have avrelatlvely large surface areavto securely hold the strip 24 in place and, while the platesv might be formed as a continuous st rip, it is preferred to employ, plates so that the U-shaped structure may most readily follow the kcurvatureof the case.
- the resistor element 22 preferably stops short, as indicated at-21, of the inner side edge of the resistor 2
- an annular relatively narrow ring 28 of insulating material is 'interposed between vthe webs 2l and the resistor element 2l adjacent the innerl portion of the element. This ring definitely maintains the spaced relationship between the strip 24 and the resistor element.
- the presser assembly Il embodies a dat plate 29 which is rigidly secured to the shaft 'I6 for I ⁇ rotation therewith.
- the plate extends radially of the shaft to a point substantially adjacent to thecontactstrip Mandisthereprovidedwithan outwardly urged presser shoe IB.
- the shoe carries a tip 2
- 'I'he point of contact between the strip and resistor element may, therefore, be'varied by infinitemmal degrees ,or steps throughout the entire length of the resistor by manipulation of the knob I1.
- the resistor does not completely encircle the interior of the case and a terminal I2 is provided for each end of the resistor.
- These terminals comprise flat plates l! (Fig. 4) arranged to overlie and contact the surface of 'the resistor element 22 at the ends of the resistor and have angularly extending contact fingers 34 (Figs. land 2) which extend through small slots Il 4in the insulating sheet Il and an elongated' slot Il in the case wall I2.
- a third; terminal 31 of 'somewhat similar constructiony is interposed between the' two resistor terminals I2 andV is electrically insulated from said terminals between the ends 38 (Fig. 2) of the resistor, which ends extend beyond the terminals 32 to position the back side thereof in overlying relation to the terminal Il.V ⁇
- Both ends of the contact strip 24 are prefer' ably connected to the third terminal 81. 1 This may be accomplished in a simple manner by forming tabs 3l (Fig. 6) 'to extend longitudinally from the contact'element and preferably from i within the case and the electrical connections with the several terminals may be effected and maintained bya single. insulated', securing means.
- the middle terminal 31 has an enlarged central aperture or recess 4l) formed therein and the wall of the case, together with the insulating sheet I9 opposite this recess, is apertured. as at 4i, to receive a screw 42 (Figs. 1, 2 and 3) which extends vinto screw threaded engagement with an arcuate plate 43.
- the plate 48 extends laterally to overlie both of the outer termiials 32 and a sheet of insulation 44 is interposed between the plate and the termlnals. ⁇
- the recess 4l is considerably larger than the screw to prevent short circuiting of the terminal VBI through the screw.
- the terminals 32 may be drawn tightly into electrical contact with the underlying ends of the resistor 2
- An electrical resistance device comprising, in combination. ⁇ i. cylindrically shaped insulator having a resistance element on the inner periphery thereof, an annular contact member disposed in opposition to the inner exposed face of said resistance element, an insulating strip extending along the length of said contact memberbetween a part of said member and the. face of said resistance' element to normally maintain said contact member from end to end in radially spaced vrelation to said resistance element, said contact member being movable radially into contact with said element. and means movable circumferentiallynrelative to said insulator and cooperating with the part of said contact member which i: free of said insulating strip for movingl saidpari into engagement with said element at variable points along the length thereof.
- An electrical 'resistance device comprising in combination, a cylindrically shaped insulatoi having a resistance element on the inner periphery thereof, an annular contact member disposed in opposition to the inner exposed face oi said resistance element, means disposed at spaced points longitudinally of said member for maint taining said member ⁇ normallyin radially spaces tosaid. element, said contact memb being movable radially outward int'o contaoi with said element.
- An electrical resistance device comprising,
- a cylindrically shaped insulator having a resistance element on the inner periphery thereof, anl annular contact member disposed in opposition to the inner exposed face of said resistance element an'd normally 'maintained in' radially spaced relation thereto, said contact member being movable radially into contact with said element.
- a cylindrically shapedelement presenting an inwardly facing resistor, an annular flexible contact member within'said element and concentrically disposed with respect to said reof the resistor between said resistor and element and a supporting portion positioned opposite the other face of the resistor for supporting the iirst mentioned portion in normally spaced relation to-said resistor.
- An electrical resistance device comprising, in
- a case having a cylindrical side wall, a resistor mounted within said side wall and facing inwardly of the case, ⁇ means for insulating said resistor from said case.- a contact Amember disposed in substantially coextensive andinor- Vmally spaced relation to said resistor and including a supporting part held between said resistor and the case. means for insulating said ⁇ contactfinember trom'the resistor and the case.
- An electrical resistance device comprising, in
- a resistor mounted within said side 'walland facing inwardly of the case, means for insulating said resistor from said case; a contact'element disposed in substantially coextensive and normally spaced relation to said resistor and including a supporting part extending between the opposite side ot the resistor and the's'ide wall.
- An electrical resistance device comprising. in combination, a case having a cylindrical side w'all, a cylindrical insulating base having 'a smooth surfaced resistor disposed on the inner periphery' thereof and dimensioned to fit'within the-case, a contact member of generallyU-shape cross sectionv arrangedto nt about the inner side edge of said base and includinga continuous contact strip, adjacent to and substantially coextensive with said resistor, insulating means separating the contact member from said case and said resistor, a terminal. connectedwith each end ofV said resistor, a separate terminal connected with both ends of said contact member, and means for variably pressing said contact strip against the resistor.
- a cylindrical insulating base having a smooth surfaced resistor disposed on the inner periphery thereof 'and dimenslonedto flt within the side wall, insulating means between the resistor and the case, a contact member of generally U-shape cross section arranged to fit about the inner side edge voi.' said base and including a continuous contact strip adiacent to and substantially coextensive with said resistor, insulating meansl separating the contact member from said re'-v sistor, insulated means for variably pressing said contact strip against the resistor, spaced termman disposed one'at each end of the resistor beyond the ends of the contact strip and in over'- lying relation to the resistor, a third terminal positioned intermediate the rst vmentioned ter-- minals, said contact member having an extension at each end behind the base for connection with said third terminal, and insulated means for securing said parts in place.
- a flexible contact member foran electrical resistance device of the character described comprising. in combination, an elongated strip constituting the contacting part of the member, a
- An electrical resistance device comprising, 'in
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- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Adjustable Resistors (AREA)
Description
rneniod'reb. la, 193s UNITED `s'l'ii-'lrzs PAT-snr oFFlcE ELECTRICAL assis'rmcn nmol 7 Y' Willy Dumke, Chicago, Ill., aaaignor 'to Utah Radio Products Company,
poration of Illinois Application July 9,1932, Serial No. 021,0 I
1o claims, (cl. soi-w having a flexible contact member of novel construction interposed therebetween for preventing wear on the resistance element or distortion of the resistance curve.
a flexible contact member' which is electrically independent of the resistance element at all times except at one point which may be optionally varied throughout the entire range of said element.
' More specifically stated, an object is to provide a resistance element of cylindrical' shape havingv theexposed surface of the resistance element in-. wardly presented and opposed by a flexible member which is maintained normally in insulated and spaced relation and which is capable of being variably contacted with the exposed surface, said 4parts having a novel arrangement which facilitates the connections thereof with the required terminals.
Another object is to provide a novel flexible contact member for a resistance element of this nature.
Other objects and advantages will become apparent in the following description -and from the accompanying drawing, in which: y
Figure 1 is anopen face view of a device em` bodying the features of the invention.
m. 2 is a sectional view through o. portion of `the device taken as indicated by the line 2-2 of Fig. 3, parts being broken away to clarify the muon. Fig. 3 is a central section through the device on the line 8 3 of Pig. 1.
m. 4 is nii-elevation or tno inferior of uio aovioe looking at the terminal assembly,
omittedfor better disclosure.
Fig. 5 is a fragmentary sectional view on an enlarged scale taken through one side of the device.
ngisafragmentaryplanviewonareduced have shown in`,the drawing and will harem describe in detail the'preferred embodiment. but it is to be' understood that l do not thereby intend to limitthe invention to the specific form disclosed-but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.
Referring to the drawing, wherein the preferred embodimentof ther invention is shown 10 merely for the purpose of illustration; Il desig- I nates generally an enclosing case or which is preferably formed of sheet metal Aor economy inv manufacture. The case is; cup-shaped and .comprises a base I I and a substantially cylindrical 15 A further object resides in the provision of such side wall I2. defining an open face which is normally closed by a suitable cover I2* (Eig. 3) which f is heldin place by tabs Il. 'Ihe base is apertured as at Il (Fig. 4) vto receive a bushing il (Fig. 3) of conventional construction within which is iour- 20 naled a shaft il arranged to be rotated by a' well-v known typeof knob or nnger piece I'i.- Theshaft I8 supports a presser assembly. generally indicated at il, the purpose of which will be herein.- after more fully described.
. Adiacent the inner surface of the side wall i2 is a sheet I! of any suitable insulating material, which preferably covers the entire wall surface. A fiat annular ring or washer Il, also of insulating material, covers a substantial portion of the 30 base of the case inwardly of said wall. An annular cylindrically shaped resistor 2| is disposed concentrically and interiorlyofY the sheet of insulating material Il but does not extend completely through the'length of the inner periphery 35 of the While'any suitable type of resistor y v .may be employed. that which is preferred comf prises a smooth surface resistor element!! (Fig. '5) .of graphite or like material mounted on or carried by a somewhat flexible base of a phenol 4o lcondensation product 23 or similar material. The --exposed surface of the resistor element is ar- V by the relatively movable contact usually em- 4s ployed, a flexible contact member is provided in interposed relation between the presser assembly and the resistor element. With particular reference to Figs. 4,-5 and 6, a preferred fonn of con tact member comprises imelongated strip 24 -cf 50 thin, nexible.- current conducting material. such asbronae,whichstripisdisposedwithinandadiacenttotheexpcsedsinfacecf tllereaistorele-` ment l2.
" The flexible strip 24 is preferably maintained as in definitely spaced and concentric relationship to the resistor element in the following manner (see Fig. 6). From one side of the strip relatively narrow webs 2l extend, each of which terminates in a ilat plate 28. The strip 24, webs 25 and plates 28 are dimensioned so that. by bending the webs along a longitudinal line, generally indicated by the line A-A in Fig. 6, adjacent the plates, a structure of generally U-shaped cross section may be obtained which will flt about or straddle the inner side edge of the resistor 2|. Thus.. the strip 24 may be maintained in deflnitely spaced relationship to the resistor element 22 by means of the webs and plates which are bound between the resistor 2| and the insulating sheet. I9 and ring 2|). The plates 26 preferably have avrelatlvely large surface areavto securely hold the strip 24 in place and, while the platesv might be formed as a continuous st rip, it is preferred to employ, plates so that the U-shaped structure may most readily follow the kcurvatureof the case.
' As maybe seen in Fig. 5, the resistor element 22 preferably stops short, as indicated at-21, of the inner side edge of the resistor 2| to insulate vthe resistor element from the contact strip. Prei'- erably. an annular relatively narrow ring 28 of insulating material is 'interposed between vthe webs 2l and the resistor element 2l adjacent the innerl portion of the element. This ring definitely maintains the spaced relationship between the strip 24 and the resistor element. l
t The presser assembly Il embodies a dat plate 29 which is rigidly secured to the shaft 'I6 for I `rotation therewith. The plate extends radially of the shaft to a point substantially adjacent to thecontactstrip Mandisthereprovidedwithan outwardly urged presser shoe IB. The shoe carries a tip 2| of insulating material which engages the contact strip :24 and pressessaid `strip into engagement with the underlying surface ofthe resistor element 22 as shown in Figs. 1 and 3. 'I'he point of contact between the strip and resistor element may, therefore, be'varied by infinitemmal degrees ,or steps throughout the entire length of the resistor by manipulation of the knob I1.
As has been mentioned, the resistor does not completely encircle the interior of the case and a terminal I2 is provided for each end of the resistor. These terminals comprise flat plates l! (Fig. 4) arranged to overlie and contact the surface of 'the resistor element 22 at the ends of the resistor and have angularly extending contact fingers 34 (Figs. land 2) which extend through small slots Il 4in the insulating sheet Il and an elongated' slot Il in the case wall I2. A third; terminal 31 of 'somewhat similar constructiony is interposed between the' two resistor terminals I2 andV is electrically insulated from said terminals between the ends 38 (Fig. 2) of the resistor, which ends extend beyond the terminals 32 to position the back side thereof in overlying relation to the terminal Il.V`
Both ends of the contact strip 24 are prefer' ably connected to the third terminal 81. 1 This may be accomplished in a simple manner by forming tabs 3l (Fig. 6) 'to extend longitudinally from the contact'element and preferably from i within the case and the electrical connections with the several terminals may be effected and maintained bya single. insulated', securing means.
Thus, as shown in Fig. 4', the middle terminal 31 has an enlarged central aperture or recess 4l) formed therein and the wall of the case, together with the insulating sheet I9 opposite this recess, is apertured. as at 4i, to receive a screw 42 (Figs. 1, 2 and 3) which extends vinto screw threaded engagement with an arcuate plate 43. The plate 48 extends laterally to overlie both of the outer termiials 32 and a sheet of insulation 44 is interposed between the plate and the termlnals.` As is shown clearly in Fig. 4, the recess 4l is considerably larger than the screw to prevent short circuiting of the terminal VBI through the screw. Thus. by the screw 42 and plate 4l, the terminals 32 may be drawn tightly into electrical contact with the underlying ends of the resistor 2| thereby pressing the back side of each end of the resistor against the. opposite sides of the middle terminal I1 to bindthe tabs I9 against the terminal 31.
It will be seen from the foregoing description vthat a device has been provided wherein the sembly and the rotating shaft therefor are electrically independent of the current carrying elements. Hence, the device is capable of carrying an yexceedingly heavy overload of -current without danger. A furtherimportant advantage is that the enclosing metallic case and cover, which are electrically independent of all circuits, provide s. static shield about the device to suppress or eliminate interference. The preferred manner of mounting the contact element in place and of maintaining said element In definitely spaced relation to the resistor facilitates assembly of these parts and results inl a structure which is inherently sturdy.
I claim as myV invention:
l. An electrical resistance device comprising, in combination. `i. cylindrically shaped insulator having a resistance element on the inner periphery thereof, an annular contact member disposed in opposition to the inner exposed face of said resistance element, an insulating strip extending along the length of said contact memberbetween a part of said member and the. face of said resistance' element to normally maintain said contact member from end to end in radially spaced vrelation to said resistance element, said contact member being movable radially into contact with said element. and means movable circumferentiallynrelative to said insulator and cooperating with the part of said contact member which i: free of said insulating strip for movingl saidpari into engagement with said element at variable points along the length thereof.
' 2. An electrical 'resistance device comprising in combination, a cylindrically shaped insulatoi having a resistance element on the inner periphery thereof, an annular contact member disposed in opposition to the inner exposed face oi said resistance element, means disposed at spaced points longitudinally of said member for maint taining said member `normallyin radially spaces tosaid. element, said contact memb being movable radially outward int'o contaoi with said element. `means movable circumferen- -tlally relative to said insulator and cooperatingwith said contact member for moving said member into engagement with said element at variable points along the length thereof, and meansl for connecting said device in an electrical circuit including a separate lterminal electrically connected with said contact member.
3. An electrical resistance device comprising,
.in combination. a cylindrically shaped insulator having a resistance element on the inner periphery thereof, anl annular contact member disposed in opposition to the inner exposed face of said resistance element an'd normally 'maintained in' radially spaced relation thereto, said contact member being movable radially into contact with said element. means movable circumferentially relative to saidv insulator and cooperating with said contact member for moving said member into engagement with said element at variable points along 'the length thereof, and means inter#l posed between apart of said contact memberand said element and vextending substantially along the lengththereof for normally spacing the one from the other.
" 4. An electrical resistance device comprising.
in combination. a cylindrically shapedelement presenting an inwardly facing resistor, an annular flexible contact member within'said element and concentrically disposed with respect to said reof the resistor between said resistor and element and a supporting portion positioned opposite the other face of the resistor for supporting the iirst mentioned portion in normally spaced relation to-said resistor.
6. An electrical resistance device comprising, in
combination, a case having a cylindrical side wall, a resistor mounted within said side wall and facing inwardly of the case,` means for insulating said resistor from said case.- a contact Amember disposed in substantially coextensive andinor- Vmally spaced relation to said resistor and including a supporting part held between said resistor and the case. means for insulating said `contactfinember trom'the resistor and the case.
and presser means supported on said case for engagement with said contact member and movable to eilect a variable 'contact of said contact manner and and resistor.
. '1. An electrical resistance device comprising, in
combination, a case having a cylindrical side wall,
a resistor mounted within said side 'walland facing inwardly of the case, means for insulating said resistor from said case; a contact'element disposed in substantially coextensive and normally spaced relation to said resistor and including a supporting part extending between the opposite side ot the resistor and the's'ide wall. meansfor insulating said contact element from. the resistor and the case, and rotatable means Journaied on the case and engaging said contact member to press the member into contact with the resistor at variable points.
An electrical resistance device comprising. in combination, a case having a cylindrical side w'all, a cylindrical insulating base having 'a smooth surfaced resistor disposed on the inner periphery' thereof and dimensioned to fit'within the-case, a contact member of generallyU-shape cross sectionv arrangedto nt about the inner side edge of said base and includinga continuous contact strip, adjacent to and substantially coextensive with said resistor, insulating means separating the contact member from said case and said resistor, a terminal. connectedwith each end ofV said resistor, a separate terminal connected with both ends of said contact member, and means for variably pressing said contact strip against the resistor. 1
combination, a case having a cylindrical side wall,
a cylindrical insulating base having a smooth surfaced resistor disposed on the inner periphery thereof 'and dimenslonedto flt within the side wall, insulating means between the resistor and the case, a contact member of generally U-shape cross section arranged to fit about the inner side edge voi.' said base and including a continuous contact strip adiacent to and substantially coextensive with said resistor, insulating meansl separating the contact member from said re'-v sistor, insulated means for variably pressing said contact strip against the resistor, spaced termman disposed one'at each end of the resistor beyond the ends of the contact strip and in over'- lying relation to the resistor, a third terminal positioned intermediate the rst vmentioned ter-- minals, said contact member having an extension at each end behind the base for connection with said third terminal, and insulated means for securing said parts in place.
10. A flexible contact member foran electrical resistance device of the character described comprising. in combination, an elongated strip constituting the contacting part of the member, a
'plurality of separate elements for support of the vcontacting part in assembly, and connections intermediate said elements and-strip adapted for bending to provide astructure of generally Uf so shaped cross section.
1 z WILLY DUMKE.
. an 9. An electrical resistance device comprising, 'in
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US621609A US2031211A (en) | 1932-07-09 | 1932-07-09 | Electrical resistance device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US621609A US2031211A (en) | 1932-07-09 | 1932-07-09 | Electrical resistance device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US2031211A true US2031211A (en) | 1936-02-18 |
Family
ID=24490870
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US621609A Expired - Lifetime US2031211A (en) | 1932-07-09 | 1932-07-09 | Electrical resistance device |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US2031211A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2457814A (en) * | 1946-08-09 | 1949-01-04 | Gordy Irving | Sealed potentiometer |
| US2736781A (en) * | 1953-06-08 | 1956-02-28 | Chicago Telephone Supply Corp | Variable resistor |
| US2826664A (en) * | 1956-03-30 | 1958-03-11 | Micro Machine Works Inc | Bridge assemblies for variable resistors |
| US3129631A (en) * | 1961-09-26 | 1964-04-21 | Unipoint Ind Inc | Braided article and method of making same |
-
1932
- 1932-07-09 US US621609A patent/US2031211A/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2457814A (en) * | 1946-08-09 | 1949-01-04 | Gordy Irving | Sealed potentiometer |
| US2736781A (en) * | 1953-06-08 | 1956-02-28 | Chicago Telephone Supply Corp | Variable resistor |
| US2826664A (en) * | 1956-03-30 | 1958-03-11 | Micro Machine Works Inc | Bridge assemblies for variable resistors |
| US3129631A (en) * | 1961-09-26 | 1964-04-21 | Unipoint Ind Inc | Braided article and method of making same |
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