US3108244A - Potentiometer - Google Patents

Potentiometer Download PDF

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Publication number
US3108244A
US3108244A US124913A US12491361A US3108244A US 3108244 A US3108244 A US 3108244A US 124913 A US124913 A US 124913A US 12491361 A US12491361 A US 12491361A US 3108244 A US3108244 A US 3108244A
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US
United States
Prior art keywords
lead screw
follower
wiper
resistance wire
wire
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
Application number
US124913A
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English (en)
Inventor
Nirenberg Morris
Sekerich Michael
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Vogue Instrument Corp
Original Assignee
Vogue Instrument Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Vogue Instrument Corp filed Critical Vogue Instrument Corp
Priority to US124913A priority Critical patent/US3108244A/en
Priority to GB4982/62A priority patent/GB936822A/en
Priority to DE19621490845 priority patent/DE1490845B2/de
Priority to FR895388A priority patent/FR1342763A/fr
Application granted granted Critical
Publication of US3108244A publication Critical patent/US3108244A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C10/00—Adjustable resistors
    • H01C10/24—Adjustable resistors the contact moving along turns of a helical resistive element, or vica versa

Definitions

  • the present invention relates generally to variable electrical resistance structures, and in particular to an infinite resolution wire wound potentiometer.
  • Potentiometers are available on the market which comprise a non-metallic cylindrical wire form which has its outer surface formed with a continuous helical groove having mounted therein a helically wound resistance wire.
  • the opposite ends of the resistance wire are elec trically connected to appropriate terminals and a movable electrical contact is made to successive portions of the resistance wire by a wiper arranged contiguous to the outer surface of the wire form.
  • the wiper underlies and engages the resistance wire and is rotatably mounted, as by being connected directly to a control shaft. Accordingly, the wiper may be rotated into various adjusted positions wherein successive portions of the resistance wire are lifted out of the helical groove and provide an adjustable and stepless output as a function of the adjusted position of the wiper.
  • Potentiometers of this type which are particularly suited for use in servo mechanisms, should have a number of essential characteristics including, without limitation, the provision of a truly stepless output, a virtually linear output, and a relatively low order of inductance and capacitance to facilitate use in alternating current circuits. Additionally, and in operation, it is important that the potentiometer produce low noise, be capable of operation at relatively low torque, and have a long life despite the wear incident to the continuous adjustment of the potentiometer and the sliding contact between the wiper and the resistance wire.
  • an infinite resolution potentiometer which comprises a mounting plate, a cylindrical wire form of an insulating material projecting from the mounting plate and having an outer surface formed with a continuous helical groove, and a helically wound resistance wire mounted within the groove.
  • the wire form is fabricated of a material of good dimensional stability and a low thermal coefficient of linear expansion, resulting in extremely high insulation resistance, low inductance and low capacitance for use in alternating current applications.
  • a lead screw is secured to the mounting plate and projects within and along the longitudinal axis of the wire form and carries a follower in threaded engagement therewith.
  • a wiper is arranged contiguous to the outer surface of the wire form and has a contact section underlying and engaging the resistance wire.
  • the wiper is mounted on the follower for movement along a helical adjustment path coextensive with the resistance wire.
  • Control means are operatively connected to the follower for rotating the follower on the lead screw to move the wiper along the adjustment path.
  • the control means includes a control shaft journal-led in the mounting plate and extending coaxially of and through the lead screw and means coupling the control shaft to the follower.
  • the potentiometer is completed by the provision of terminal means electrically connected to the opposite ends of the resistance wire and a collector electrically and rotatably connected to the wiper for providing an appropriate tapotf.
  • the lead screw and follower may be machined to an exceptionally high order of accuracy and with the same pitch as the helically wound resistance wire to assure that the wiper or brush will follow the exact helical path of the resistance wire, with substantially no sliding or helical error.
  • FIG. 1 is an elevational view of an infinite resolution potentiometer demonstrating features of the present invention, with the cylindrical case or cover sectioned to reveal the contents thereof;
  • FIG. 2 is an elevational view taken from the right of FIG. 1, with the case of cover sectioned and with parts broken awa
  • FIG. 3 is a sectional view taken substantially along the lines 3-3 of FIG. 1 and looking in the direction of the arrows;
  • FIG. 4 is a sectional view taken substantially along the lines 4-4 of PEG. 3, looking in the direction of the arrows and with a portion of the case broken away;
  • PEG. 5 is a sectional view taken substantially along the lines of 5-5 of FIG. 4 and looking in the direction of the arrows;
  • FIG. 6 is a sectional view similar to FIG. 3 but showing a modification in the collector for electrically connecting the rotatable and longitudinally movable wiper to an appropriate terminal.
  • FIGS. 1 to 5 inclusive a potentiometer 10' which illustrates features of the present invention and includes a housing 12 having a mounting or base plate 14 and a reinovable cylindrical case or cover 16.
  • the mounting or base plate 14 is appropriately dimensioned and shaped for mounting in an environment structure and is formed in a marginal seat 14a which receives the adjacent end of the removable case or cover :16.
  • both the mounting plate 14 and the cover 16 may be fabricated of anodized aluminum or similar light weight material.
  • a cylindrical wire forin 1'8 Projecting from the mounting plate 14 internally of the case '16 is a cylindrical wire forin 1'8 which is fabricated of an appropriate non-metallic material having good dirnension-al stability and a low thermal coefficient of linear expansion, such as a fiuoro-carbon.
  • the outer periphery or surface of the cylindrical wire form 18 is provided with a continuous helical groove 20, shown here for the purposes of illustration on a greatly exaggerated scale.
  • the helical groove 20, which is precision ground and is of generally V-shaped section (see FIG. 3), receives a helically wound resistance wire 22 which may be fabricated of a hard drawn chrome-nickel alloy.
  • the depth of the helical groove 20 is sufiicient to accommodate the resistance wire 22 within the confines of the groove (see FIGS. 3 to 5 inclusive). Although only one groove cross section has been illustrated, it will be appreciated that other groove cross sections will be suitable for accommodating the resistance wire.
  • the cylindrical wire form 155 is mounted within the case 16 by the provision of an annular retaining flange 1412 on the mounting plate '14 (see H68. 3 and 4) which has an outer diameter substantially equal to the inner diameter of the wire form 18.
  • the wire form 18 is fitted over the annular retaining flange 14b and is secured to the mounting plate 14 coaxially thereof by the provision of one or more mounting bolts 2 (see FIGS. 4 and 5) which extend lengthwise through the wire form 18- and are threaded into appropriately tapped holes 140 formed in the adjacent end of the mounting plate 14 at locations spaced radially outwardly of the retaining flange 14b.
  • the mounting plate 14 supports a stationary hollow lead screw 26 which projects within and along the longitudinal axis of the wire form -13.
  • the stationary lead screw 26 includes an integral lead screw mounting section 26:: and a threaded section 26b.
  • the mounting section 26a has an outer diameter substantially equal to the inner diameter of the annular retaining flange 1412 such that the mounting section 26a may be oriented to have threaded section 26 project axially of the wire form l8.
  • the mounting section 26:: is secured to the mounting plate '14 within the annular retaining flange 14b by a number of mounting bolts 28.
  • the threaded or lead screw section 26b is formed with a through bore 260 and projects beyond the wire form 18, for a purpose to be subsequently described.
  • the threaded section 26b of the lead screw 26 carries a follower assembly 36 which includes a follower nut 32 in threaded engagement with the lead screw section 26b, an insulating block 34 secured to the follower nut 32, a substantially L-shaped mounting arm 36 of electrically conductive material secured to the insulating block 3 3-, and a wiper or brush 38 secured to the mounting arm 36.
  • the wiper or brush 38 extends generally parallel to the longitudinal axis of the wire form 18 and terminates in a contact section 38a which underlies and engages successive portions of the resistance wire 22.
  • the follower assembly 30 is rotated about and along the lead screw 26 to move the wiper or brush 38 along a helical adjustment path coextensive with the resistance wire 22 such that the transverse segment of the contact section 38a underlying the resistance wire 22 may make continuous contact with successive portions of the restistance wire 22.
  • the transverse segment of the contact section 33a underlying the resistance wire 22 may be slightly grooved or notched to preclude sidewise displacement between the contact and the resistance wire.
  • the provision of such groove or notch is optional since the pitch of the lead screw section 26!) and the pitch of the helical groove 2% is the same and may be held to extremely close tolerances due to the precision grinding or cutting of the lead screw and of the wire groove.
  • the wiper or brush 33 is fabricated of a resilient alloy, such as beryllium-copper and is formed with a reucked neck 38b intermediate the contact section 38a and the mounting arm 36 to allow the contact section 38a to flex.
  • the contact section is bowed on an :arc corresponding to the outer periphery of the wire form 18 such :as not to present any sharp discontinuity to the resistance wire 22 as the contact section moves therebeneath.
  • the contact section 38a may be of precious metal, such as a platinum alloy.
  • a control assembly or mechanism is operatively connected to the follower nut 32 for rotating the follower nut 32 on the lead screw 26 to move the contact section 38a of the wiper or brush 3% along the adjustment path in electrical contact with the resistance wire 22.
  • the mounting section iita of the control shaft 4% is journalled within the mounting plate 14 by the provision of two precision bearings 42, '44 which have their outer races secured to the mounting plate 14 and have their inner races secured to the mounting section itia, with the control shaft 445* being held against endwise play by appropriate washers or stops &6, 48.
  • the control section 40b carries a crosshead 50 which is secured to the control section 4% of the control shaft as in any appropriate fashion, as by the pin 52 (see FIG. 3).
  • the cross head 59 in turn carries a pair of spaced and parallel drive fingers 54, 56 which project from the cross head 5% towards the follower nut 32 at opposite side of and equally spaced from the control shaft 49.
  • the drive fingers 54, 56 are slidably engaged in diametrically opposed cutouts 32a, 321) (see FIG. 5) formed in the follower nut 32.
  • the crosshead 50 and drive fingers 54, 56 will rotate and cause the follower nut 32 to move along the threaded section 26b of the lead screw 26, with the follower nut 32 sliding relative to the drive fingers 54, 56.
  • Collector means are electrically and rotatably connected to the wiper 38 for providing a tap-01f and stepless output.
  • the collector means includes a collector cylinder'58 which is fabricated of an appropriate precious metal and is mounted coaxially of and within the wire form 18, as seen best in FIGS. 2 to 5 inclusive.
  • the collector cylinder 58 is of suflicient longitudinal extent to be engaged by movable contacts or brushes 60 which are electrically connected to the wiper mounting arm 36 and supported there on in engagement with the inner peripheral surface of the collector cylinder 58.
  • the movable contacts 60 are fabricated of any appropriate springy material which biases the same into contact with the collector cylinder 58, with the cont-act '60 moving along a helical contact path in response to rotation of the follower nut 32 on the lead screw 26.
  • the stepless output is made available .at a tapolf lead 62 which is electrically connected to the coleetor cylinder 58 and extended through a cutout 18a and the wire form 18.
  • Terminal connections are provided to the opposite ends of the resistance wire 22 in any appropriate fashion.
  • two terminal strips 64, 66 are mounted longitudinally of land within the wire form 18 (see FIGS. 1 and 3) at locations radially inwardly of the outer periphery of the wire form.
  • the terminal strip 64 has an electrical connection to the end of the resistance wire 22 contiguous to the mounting plate 14, and to a terminal lead 68, while the terminal strip 66 has an electrical connection to the end of the resistance wire 22 remote from the mounting plate 14 and an electrical connection to a terminal lead 70.
  • the follower nut 32 is provided with movable stop pins 72, 74 projecting from the opposite face thereof.
  • the stop pin 72 limits the travel of the follower nut to the right in FIGS. 3 and 4 while the stop pin 74 limits the travel of the follower nut to the left in FIGS. 3 and 4.
  • the stop pin 72 cooperates with an adjustable end stop 76 which is secured to the stationary lead screw section 26b adjacent the free end thereof inwardly of the cross head 50.
  • the end stop 76 carries.
  • a stationary stop pin 78 which is radially spaced from the longitudinal axis of the lead screw 26 to be contacted by the movable stop pin 72.
  • the end stop 76 is bifurcated and pro vided with opposed ears 76a, 76b (see FIG. 2) which ears are traversed by an adjustment and locking screw 8% which enables the release and securement of the end stop 76 in any adjusted position on the lead screw section 26b.
  • the contact pressure of the wiper or brush 38 may be established to provide relatively low frictional contact with the resistance wire 22 yet achieving the necessary electrical tapoff thereby assuring long life and relatively low wear. Further, since the wiper or brush 38 follows the exact helical path of the resistance wire 22 there Will be a minimum sliding or helical error between the contact and wire. By appro priate selection of materials and control in manufacturing tolerances, a high order of linearity may be attained for the potentiometer and optimum mechanical conditions may be established for the product.
  • FIG. 6 shows a modification of the high resolution potentiometer, particularly in the construction of the collector means which electrically and rotatably connects the movable wiper or brush to the resistance wire for providing the stepless output. Since the construction of this potentiometer is subsubstantially identical to that previously described, corresponding parts will be designated by the same reference numeral as a part of a 100 series and the detailed de scription will be limited only to the construction of the collector means which may be employed in lieu of the collector cylinder 58 and the brushes 6t Specifically, an annular collector ring 158 is mounted on the end face of the wire form 118 remote from the mounting plate 114-.
  • the collector ring which is in the form of a fiat annulus, is disposed concentrically of the lead screw 126 and electrically contacted by the movable contacts or brushes 160 which are mounted on the cross head 156 by an appropriate insulating block 161.
  • the insulating block 161 is secured to the cross head 150 by appropriate mounting screws or bolts 163, while the brushes 16d are connected to a terminal plate 165 which is riveted or otherwise secured to the insulating block 161.
  • the electrical connection from the brushes 16% via the terminal plate 165 to the wiper mounting arm 136 and to the brush or wiper (not shown but comparable to the brush or wiper 138) is completed by the provision of a jumper wire 167 which is electrically connected at one end to the terminal plate 165 and at the other end to the wiper mounting arm 136.
  • the jumper wire 167 is flexible and is of suificient length such as not to interfere with the movement of the follower nut 132 along the lead screw 126 and yet provides the necessary electrical connection between the movable follower assembly and the stationary collector ring 158.
  • the brushes 160 traverse the same annular contact paths on the collector ring 158 and may be initially constructed to be of a relatively narrow width comparable to the spacing between the brushes. Obviously, this represents a saving as compared to the use of the relatively long cylindrical collector ring 58 and results in manufacturing economies, particularly when it is recalled that the collector ring is usually fabricated or plated of a precious metal.
  • An infinite resolution potentiometer comprising a mounting plate, a cylindrical wire form of an insulating material projecting from said mounting plate and having an outer surface formed with a continuous helical groove, a helically wound resistance wire mounted within said groove, a stationary lead screw secured to said mounting plate and projecting within and along the longitudinal axis of said wire form, a follower in threaded engagement with said lead screw, a wiper arranged contiguous to said outer surface of said wire form and having a cont-act section underlying and engaging said resistance wire, means mounting said wiper on follower for movement along a helical adjustment path coextensive with said resistance wire, and control means operatively connected to said follower for rotating said follower on said lead screw to move said wiper along said adjustment path.
  • An infinite resolution potentiometer comprising a mounting plate, a cylindrical wire form of an insulating material projecting from said mounting plate and having an outer surface formed with a continuous helical groove, a helically wound resistance wire mounted within said groove, a stationary hollow lead screw secured to said mounting plate and projecting within and along the longitudinal axis of said wire form, a follower in threaded engagement with said lead screw, a wiper arranged contiguous to said outer surface of said wire form and having a contact section underlying and engaging said resistance wire, means mounting said wiper on follower for movement along a helical adjustment path coextensive with said resistance wire, and control means operatively connected to said follower for rotating said follower on said lead screw to move said wiper along said adjustment path, said control means including a control shaft journalled in said mounting plate and extending coaxially of and through said lead screw and means coupling said control shaft to said follower.
  • An infinite resolution potentiometer comprising a mounting plate, a cylindrical wire form of an insulating material projecting from said mounting plate and hav ing an outer surface formed with a continuous helical groove, a helically wound resistance wire mounted within said groove, a stationary hollow lead screw secured to said mounting plate and projecting within and along the longitudinal axis of said wire form, a follower in threaded en gagement with said lead screw, a wiper arranged contiguous to said outer surface of said wire form and having a contact section underlying and engaging said resistance wire, means mounting said wiper on follower for movement along a helical adjustment path coextensive with said resistance wire, control means operatively connected to said follower for rotating said follower on said lead screw to move said wiper along said adjustment path, and collector means electrically and rotatably connected to said wiper for providing a tapofi connection thereto.
  • collector means includes a collector cylinder coaxial-1y of and within said wire form, and brush means in rotatable contact with said collector cylinder and electrically connected to said wiper.
  • collector means includes an annular collector ring extending transversely of said longitudinal axis and mounted on said wire form, and brush means in rotatable contact with said Collector ring and'electrically connected to said wiper.
  • An infinite resolution potentiometer comprising a mounting plate, a cylindrical wire form of an insulating material projecting from said mounting plate and having an outer surface formed with a continuous helical groove, 3. helically wound resistance wire mounted within said groove, a stationary hollow lead screw secured to said mounting plate and projecting within and along the longitudinal axis of said wire form, a follower in threaded engagement with said lead screw, a wiper arranged contiguous to said outer surface of said wire form and having a contact section underlying and engaging said resistance Wire, means mounting said wiper on follower tfOl' movement along .a helical adjustment path coextensive with said resistance wires, control means operatively connected to said follower for rotating said follower on said lead screw to move said wiper along said adjustment path, said control means including a control shaft journalled in said rounting plate' and extending coaxially of and through said lead screw and means coupling said control shaft to said follower, collector means electrically and rotatably connected to said wiper for providing
  • collector means includes a collector cylinder coaxiaily of and within said wire form, and brush means in rotatable contact with said collector cylinder and electrically connected to said wiper.
  • said collector means includes an annular collector ring extending transversely of said longitudinal axis and mounted on said wire form, and brush means in rotatable contact with said collector ring and electrically connected to said wiper.
  • mounting means including a wire form having a helical groove, a resistance wire mounted in said groove, a stationary lead screw supported on said mounting means and extending axially of said resistance Wire, said lead screw having a pitch substantially corresponding to the pitch of said helical groove, a follower engaging said lead screw and 8 control means opcratively'connected to said follower for rotating said follower.
  • An infinite resolution potentiometer comprising mounting means including a wire form having a helical groove, a resistance wire mounted in said groove, a stationary lead screw supported on said mounting means and extending axially of said resistance wire, said lead screw having a pitch substantially corresponding to the pitch of said helical groove, a follower engaging said lead screw and movable therealong in response to being rotated, a brush underlying said resistance wire and operatively connected to said follower for movement therewith and making contact with successive portions of said resistance wire, control means oper atively connected to said follower for rotating said follower, collector means electrically connected to said brush and including a stationary terminal providing a stepless output from said brush, and terminal means electrically connected to the opposite ends of said resistance wire respectively.
  • An infinite resolution potentiometer comprising mounting means including a wire form having a helical groove, a resistance wire mounted in said groove, a stationary lead screw supported on said mounting means and extending axially of said resistance wire, said lead screw having a pitch substantially corresponding to the pitch of said helical groove, a follower engaging said lead screw and movable therealong in response to being rotated, a brush underlying said resistance wire and operatively connected to said follower for movement therewith and making contact with successive portions of said resistance wire, control means operatively connected to said follower, said control means including a control shaft journal-led on said mounting means and extending coaxially of and through said lead screw and drive means carried on said control shaft and slidably coupled to said follower for rotating said follower, collector means electrically connected to said :brush and including a stationary terminal providing a stepless output from said brush, and terminal means electrically connected to the opposite ends of said resistance wire respectively.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Adjustable Resistors (AREA)
  • Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
  • Current-Collector Devices For Electrically Propelled Vehicles (AREA)
US124913A 1961-07-18 1961-07-18 Potentiometer Expired - Lifetime US3108244A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US124913A US3108244A (en) 1961-07-18 1961-07-18 Potentiometer
GB4982/62A GB936822A (en) 1961-07-18 1962-02-08 Infinite resolution potentiometer
DE19621490845 DE1490845B2 (de) 1961-07-18 1962-04-09 Wendelpotentiometer
FR895388A FR1342763A (fr) 1961-07-18 1962-04-24 Potentiomètre

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US124913A US3108244A (en) 1961-07-18 1961-07-18 Potentiometer

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US3108244A true US3108244A (en) 1963-10-22

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US124913A Expired - Lifetime US3108244A (en) 1961-07-18 1961-07-18 Potentiometer

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US (1) US3108244A (fr)
DE (1) DE1490845B2 (fr)
FR (1) FR1342763A (fr)
GB (1) GB936822A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3356823A (en) * 1964-07-10 1967-12-05 John W Waters Arc welding electrode holder
US3365690A (en) * 1966-02-04 1968-01-23 California General Inc Potentiometer
US3436714A (en) * 1966-12-24 1969-04-01 Cts Corp Variable resistance control having a resistance wire supporting cylindrical substrate
US20080158042A1 (en) * 2006-07-10 2008-07-03 Omron Corporation Radar device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU737736B2 (en) * 1997-07-21 2001-08-30 Procter & Gamble Company, The Improved alkylbenzenesulfonate surfactants

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2773966A (en) * 1953-08-10 1956-12-11 G M Giannini & Co Inc Variable electrical resistance structure
US2813182A (en) * 1955-03-10 1957-11-12 Borg George W Corp Potentiometer adjuster
US2887555A (en) * 1957-09-09 1959-05-19 Beckman Instruments Inc Potentiometer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2773966A (en) * 1953-08-10 1956-12-11 G M Giannini & Co Inc Variable electrical resistance structure
US2813182A (en) * 1955-03-10 1957-11-12 Borg George W Corp Potentiometer adjuster
US2887555A (en) * 1957-09-09 1959-05-19 Beckman Instruments Inc Potentiometer

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3356823A (en) * 1964-07-10 1967-12-05 John W Waters Arc welding electrode holder
US3365690A (en) * 1966-02-04 1968-01-23 California General Inc Potentiometer
US3436714A (en) * 1966-12-24 1969-04-01 Cts Corp Variable resistance control having a resistance wire supporting cylindrical substrate
US20080158042A1 (en) * 2006-07-10 2008-07-03 Omron Corporation Radar device

Also Published As

Publication number Publication date
DE1490845B2 (de) 1971-07-22
FR1342763A (fr) 1963-11-15
GB936822A (en) 1963-09-11
DE1490845A1 (de) 1969-07-17

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