US3745503A - Galvano-magnetro effect apparatus - Google Patents

Galvano-magnetro effect apparatus Download PDF

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Publication number
US3745503A
US3745503A US00280992A US3745503DA US3745503A US 3745503 A US3745503 A US 3745503A US 00280992 A US00280992 A US 00280992A US 3745503D A US3745503D A US 3745503DA US 3745503 A US3745503 A US 3745503A
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United States
Prior art keywords
yoke
lower yoke
rotating shaft
support base
screw
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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
US00280992A
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English (en)
Inventor
T Kobayashi
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Denki Onkyo Co Ltd
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Denki Onkyo Co Ltd
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Publication date
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
    • G01R33/06—Measuring direction or magnitude of magnetic fields or magnetic flux using galvano-magnetic devices
    • G01R33/09—Magnetoresistive devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N50/00—Galvanomagnetic devices
    • H10N50/10—Magnetoresistive devices

Definitions

  • the present invention relates to the galvanomagnetro effect apparatus employing the magnetroresistance effect device.
  • the present invention provides the galvanomagnetro effect apparatus which can eliminate the disadvantages described above.
  • the present invention is comprised of a base plate provided with a through hole, a magentic upper yoke attached under said base plate, a flexible and magnetic lower yoke oppositely arranged parallel with said upper yoke, at least one magnet positioned between said upper yoke and lower yoke, a rotating shaft whose lower end inserted into the through hole of said base plate is positioned close to said lower yoke and main part is forced to contact said upper yoke, a magnetroresistance effect device fixed above said lower yoke so that the device is opposed to the lower end of said rotating shaft and a pushing means which pushes up the device mounting position of said lower yoke from the underside, wherein said rotating shaft has the lower part, below the position where the shaft contacts said upper yoke, which is made of a magnetic material so that a lower part forms a closed magnetic path by being combined with said upper yoke, lower yoke and magnet and a projected end which is provided at the lower end
  • FIG. 1 is a plan view of the apparatus according to the present invention
  • FIG. 2 is a cross sectional view as seen along line "-11 in FIG. 1,
  • FIG. 3 is a cross sectional view as seen along line III- ---III in FIG. 1,
  • FIG. 4 is a bottom view as seen along line lVIV in FIG. 2,
  • FIG. 5 is a plan view as seen along line V-V in FIG.
  • FIGS. 6 and 7 are respectively cross sectional views illustrating another embodiment of the apparatus
  • FIG. 8 is a plan view illustrating another embodiment of the lower yoke to be employed in the apparatus.
  • FIGS. 9 and 10 are respectively cross sectional views illustrating another embodiment of the pushing means to be employed in the apparatus.
  • FIG. 11' is a bottom view illustrating another embodiment of the pushing means
  • FIGS. 12 to 14 are respectively plan views illustrating the embodiment of the magnetro-resistance effect device to be employed in the apparatus.
  • an galvanomagnetro effect apparatus comprising base plate 10 provided with through hole 11 at its center, upper yoke 20 fixed to said base plate so that the upper yoke surrounds said through hole, pressing means 40 such as, for example, the support base which is opposed in parallel with said upper yoke and is connected to the upper yoke with coupling lever 30, at least one magnet 50 which is interpositioned between said upper yoke and support base, lower yoke 60 provided between said magnet 50 and support base 40, a magnetro-resistance effect device which are provided on the lower yoke so that the device is opposed to the lower end of rotating shaft 70 inserted into the through hole of said base plate with a slight gap, cover attached to said support base 40, and casing provided with base plate 10 which forms the external housing by being combined with said cover.
  • Base plate 10 is made of a non-magnetic material in the shape of lozenge and provided with a base plate fixing means such as, for example, two screw holes at both sides of its longitudinal direction.
  • Through hole 11 is provided at the center of base plate 10 and a cylindrical wall is provided along the circumferential direction in reference to the through hole, thus forming casing 100 which is open downward.
  • Upper yoke 20 is made of a magnetic material in the form of funnel which is open upward, provided with through hole 21 is opposed to the through hole of said base plate and is fixed to base plate 10 so that its open end contacts the lower surface of base plate 10 to cover the through hole of said base plate 10.
  • the fixing means for upper yoke 20 can be freely made. However, as shown in FIG. 2, screw 22 is generally employed. Low-friction bearing 10 provided with through hole 111 into which rotating shaft 70 is inserted is housed in theinternal room of said upper yoke 20.
  • Bearing can be made of a synthetic resin as shown in FIG. 2 or can be a bearing as shown in FIG. 6.
  • Support base 40 employed as the pushing means in this embodiment is connected to upper yoke 20 as shown in FIG. 3 through coupling rod 30 such as a threaded rod, etc.
  • the distance between support base 40 and upper yoke 20 can be adjusted in accordance with the length of coupling rod 30 in the space formed between the upper yoke and the lower yoke.
  • Support base 40 is generally made in the form of disc; however, its shape can be freely changed in accordance with the shape of the casing and, as shown in FIG. 11, the shape can be rectangular depending on the case.
  • Protuberance 41 facing upward is provided at the center of support base 40 and is forced to contact the center of lower yoke 60.
  • Protuberance 41 can be spherical as shown in FIG. 2, can be stepped as shown in FIGS. and or can be an end of screw 41 which is inserted through the center of support base 40 and projected from the support base as shown in FIG. 6.
  • the height of the protuberance can be adjusted by rotating the screw.
  • Lower yoke 60 is mounted on support base 40 and at least one magnet 50 is positioned between lower yoke 60 and upper yoke 20.
  • lower yoke 60 is made in a cross shape and coupling rod 30 is inserted into each space between extended arms 61.
  • Lower yoke 60 can be a flat plate such as, for example, a disc-shaped plate. In this case, it is desirable to provide long through holes 62 along the circumferential direction into which coupling rods 30 are inserted.
  • One pole end of magnet 50 contacts each extended arm 61 of lower yoke 60 and the other pole end of this magnet 50 contacts the lower surface of upper yoke 20.
  • the pole ends of magnet 50 contacting extended arms 61 provide the same polarity and accordingly the magnetic flux concentrates in rotating shaft 70.
  • a plural number of magnets 50 need not be employed; for example, one cylindrical magnet having the poles at its both ends can be employed as shown with a dotted line in FIG. 8.
  • Rotating shaft 70 is entirely made of a magnetic material as shown in FIG. 2 or the part below the position which contacts the upper yoke is made of a magnetic material as shown in FIG. 6, accordingly, rotating shaft 70, lower yoke 60, magnet 50 and upper yoke are combined to form the closed magnetic flux'path.
  • the length of rotating shaft 70'projected into-the casing is limited by stopper 71 so that the lower end at the insertion side is opposed to lower yoke 60 with a slight interval.
  • rotating shaft 70 is divided into semi-circular projected end 72 and semi-circular chipped portion 73 and the projected end eccentrically moves in reference the axis of the rotating shaft along with rotation of the rotating shaft.
  • said projected end 72 can be made by connecting the magnetic shaft having a semi-circular section to the non-magnetic rotating shaft.
  • Magnetroresistance effect device 80 is fixed at the surface of lower yoke 60 opposed to the inserted free end of rotating shaft 70.
  • Device 80 is of the three-terminal type if the apparatus according to the present invention is a potentiometer. It is positioned on the circular surface of the lower yoke corresponding to the circle formed when projected end 72 meshes with chipped portion 73 and is formed so that a pair of symmetrical magnetism sensing surfaces are provided at both ends of the intermediate terminal.
  • Device 80 shown in FIG. 11 is made up by forming main part 81 of the device in the shape of a chipped circle and providing terminals 82 and 82 to be connected to power supply S at both ends and intermediate terminal 83 to be connected to load L at the intermediate position.
  • the resistance value of magnetism sensing surfaces 84 and 85 varies along with rotation of projected end 72 of rotating shaft shown with a broken line and the output obtained from intermediate terminal 83 varies.
  • Device shown in FIG. 12 is made up by seriesconnecting two meandering elements and combining magnetism sensing surface 84 of one element and mag netism sensing surface of the other element as a pair.
  • Said three-terminal device is such that the resistance value of magnetism sensing surfaces 84 and 85 between two terminals changes alternately due to eccentric movement of projected end 72.
  • a device other than the device described above such as, for example, the two-terminals device as shown in FIG. 14 can be employed for this purpose.
  • a device made in the semi-circular shape can be opposed to the projected end of rotary shaft and thus the resistance value between the terminals can be varied by eccentric movement of the projected end.
  • Each device is provided with short bar in order to the magnetism sensitivity as conventional device.
  • Cover is attached to support base 40 with screw 42.
  • Cover 90 is fitted to casing to form the housing.
  • support base 40 is made to be rectangular as shown in FIG. 11, screw hole 43 is provided at the centerto attach cover 90 to the underside of support base 40, and screw holes 44 are provided at both ends, into which coupling rods 30 are inserted.
  • the pushing means need not be the support base.
  • lower yoke 60 can be fixed to support frame 91 of cover 90 and lower yoke 60 can be pushed by inserting screw 41'.
  • the apparatus according to the present invention is as described above. Therefore, if the specified output characteristics are not obtained due to slight difference in the dimensions arising from inaccurate machining of a part such as the upper yoke, rotating shaft or magnet, improper magnetization, irregularity in the characteristic of the element, etc., the gap formed between device 80 and rotating shaft 70 can be reduced by making the pushing means push the center of lower yoke 40, that is, the device fixing position and the magnetic flux density applied to the device can be adjusted.
  • support base 40 is raised by rotating coupling lever 30 in case of the embodiment shown in FIG. 2 and the projecting length of screw 41 can be increased by rotating screw 41 in case of the embodiment shown in FIG. 6.
  • the lower yoke is pushed by rotating inserted end 41' of screw 40 at the outside of cover 90.
  • lower yoke 40 to be selected should be variable in its shape. Since adjustment of the gap is actually approximately 0.5 mm, itis not necessary to select a material with excellent flexibility for the lower yoke.
  • the gap is generally adjusted by reducing it. Therefore, in practical use, it is desirable to adjust the output while reducing the gap which has been set to be a little larger than the specified value in assembly.
  • a galvano-magnetro effect apparatus comprising:
  • a magnetro-resistance effect device which is provided at the lower yoke surface so that it is opposed to the lower end of said rotating shaft
  • said rotating shaft has the part, below the position where it contacts said upper yoke, being made of a magnetic material so that said part is combined with upper yoke, lower yoke and magnet to form the closed magnetic path, said magnet is so arranged that one magnetic pole contacts the upper yoke and the other magnetic pole contacts the lower yoke and the magnetic flux can be concentrated into the gap formed between the projected end of the rotating shaft and the device, said device is provided with at least two terminals and is designed so that the area of the magnetism sensing surface between the terminals opposing to the projected end varies with eccentric movement of the projected end and said pushing means is devised so that the pushing force applied to the lower yoke is changed by pushing the device fixing part of said lower yoke toward the projected end.
  • said pushing means is comprised of a support base, which is mounted with the lower yoke on its surface and is provided with a protuberance which contacts the lower surface of the device fixing part of the lower yoke, and
  • a coupling rod which couples the support base to the upper yoke so that the length of the rod between the upper yoke and the support base can be changed.
  • said pushing means is comprised of the support base on which the lower yoke is mounted and a screw which is screw-fitted into the support base so that the extreme end of the screw projected above the support base contacts the lower surface of the device fixing part of said lower yoke, and said projected end of said screw forms said protuberance.

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  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Adjustable Resistors (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)
US00280992A 1971-08-16 1972-08-16 Galvano-magnetro effect apparatus Expired - Lifetime US3745503A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1971073204U JPS4830339U (enrdf_load_html_response) 1971-08-16 1971-08-16

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US3745503A true US3745503A (en) 1973-07-10

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JP (1) JPS4830339U (enrdf_load_html_response)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2735673A1 (de) * 1976-08-06 1978-02-09 Denki Onkyo Co Ltd Potentiometer
US4125821A (en) * 1977-08-05 1978-11-14 Denki Onkyo Company, Limited Potentiometer providing a non-linear output
US4673876A (en) * 1984-03-08 1987-06-16 General Scanning, Inc. Two-element angular positive sensor for rotatable shaft
US6175296B1 (en) * 1998-07-17 2001-01-16 Alps Electric Co., Ltd. Potentiometer provided with giant magnetoresistive effect elements
US7405457B1 (en) * 2003-05-28 2008-07-29 Adsem, Inc. High temperature thermistors

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2735673A1 (de) * 1976-08-06 1978-02-09 Denki Onkyo Co Ltd Potentiometer
US4132970A (en) * 1976-08-06 1979-01-02 Denki Onkyo Company, Limited Potentiometer
US4125821A (en) * 1977-08-05 1978-11-14 Denki Onkyo Company, Limited Potentiometer providing a non-linear output
US4673876A (en) * 1984-03-08 1987-06-16 General Scanning, Inc. Two-element angular positive sensor for rotatable shaft
US6175296B1 (en) * 1998-07-17 2001-01-16 Alps Electric Co., Ltd. Potentiometer provided with giant magnetoresistive effect elements
US7405457B1 (en) * 2003-05-28 2008-07-29 Adsem, Inc. High temperature thermistors

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Publication number Publication date
JPS4830339U (enrdf_load_html_response) 1973-04-13

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