Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
  • G01B7/02—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring length, width or thickness
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/02—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using mechanical means
  • G01D5/06—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using mechanical means acting through a wall or enclosure, e.g. by bellows, by magnetic coupling
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
  • G01D5/24—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying capacitance
  • G01D5/2403—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying capacitance by moving plates, not forming part of the capacitor itself, e.g. shields

Definitions

• the present invention relates to displacement transducers and more
• potentiometer is the friction inherent to the sliding contact and the
• transducer is based on a displacement dependent magnetic coupling
• each of said stationary members comprising one or more than
• a movable member or plate or electrode
• the monitored body body or element the displacement of which is to be measured
• said movable and second stationary members constitute
• stationary member are preferably means, such as a transimpedance
• the input alternating tension is preferably applied to the first
• the first stationary member may be called
• the movable member may be called “signal plate” or “electrode”.
• the first stationary member may be called "displacement plate” or "electrode"
• the first stationary member may be called "displacement plate" or "electrode"
• member comprises two stationary excitation plates, to which two opposite
• phase AC voltages are applied.
• phase AC voltages are applied.
• said two plates are triangular and arranged so that the base of each of them
• the stationary plates may be arranged in cylindrical form, e.g., as
• the movable plate may be formed on a piston which slides within said
• each stationary plate is
• the excitation plate further comprises
• each electrode pair being excited by a complementary
• kinematic means may be of any kind, and may be e.g., kinematic means of any convenient
• structure may include an electromagnetic coupling.
• body according to the invention comprises providing at least two
• capacitances including at least one movable plate, displacing said movable plate as a function of the displacements of the monitored body, applying
• three capacitances including one movable plate and
• Figs. 1-a and 1-b are a diagram of a device according to a first
• Figs. 2-a and 2-b are a diagram of a device according to a second
• Figs. 3-a and 3-b are a diagram of a device according to a third
• Fig. 4-a and 4-b show two constructional implementations
• Fig 5 illustrates a cylindrical constructional implementation of Figs.
• Fig. 6 shows a constructional implementation, schematically
• Fig. 7 shows a constructional implementation, schematically
• embodiment of the invention including coarse and fine channels
• Fig. 8 shows an actual mask use for screen printing coarse and fine
• Fig. 9 illustrates an hermetically sealed device according to an
• Fig. 10 illustrates a device according to a further embodiment of the
• Fig. 11 illustrates a device according to a still further embodiment
• Fig. 1(a) diagrammatically illustrates a transducer device according
• Electrode 6 is capacitively coupled to said electrodes 1 and 3.
• members 1 and 3 consists of a fixed capacitance C 3 and two
• V 0 which is the output of the transimpedance amplifier 5
• V ex is the excitation voltage applied to
• FIG. 1 A modified configuration of the transducer device is shown in Fig.
• Fig. 3(a) illustrates an embodiment wherein the first stationary
• phase of the output voltage varies and is indicative of the sense
• sum signal can be used to normalize the differential signal against common
• the input AC voltage can be applied to the signal plate
• FIG. 4(a) shows a
• the plates can actually be flat bodies, or the drawing can be understood to represent the development on a plane of
• Excitation plates 1 and 2 are identical to Excitation plates 1 and 2
• Capacitance . 3 is therefore constant and capacitances C,. 6 and C 2 . 6 are
• FIG. 4(b) illustrates a modification to the configuration of Fig. 4(a)
• the stationary plates are cylindrical, in particular, they are disposed on a
• the stationary plates can be made by
• Figs. 4(a) or 4(b) can be taken as representing the surface of the
• movable piston can be made from a low friction conductive material such as
• the piston can be made from a Teflon-coated
• FIG. 5 includes a rod 10 that serves mechanically to couple
• actuator /displacement transducer is useful in various pneumatic systems
• the stationary plates of the transducer of the present invention are identical to the stationary plates of the transducer of the present invention.
• the stationary plates and piston 9 is sensitive to radial misalignment of the
• This sensitivity can be decreased by employing, in place of
• FIG. 7 illustrates another embodiment of the invention, wherein an
• additional channel comprises two periodic patterns, shown as triangular in
• the second pattern includes the electrodes 12 and 13 whereas the second pattern includes
• Electrodes 14 and 15 Each electrodes pair is excited with two opposite
• the fine channels enable an interpolation within an individual cycle
• Fig. 8 illustrates an actual mask used for screen printing plates on
• FIG. 9 illustrates
• the momtored body is obtained by the interaction between two concentric elements
• Numeral 8 designates a non-conductive cylinder as in Fig. 5.
• a first cylindrical magnet 16 is mounted within piston 9 and a second
• annular magnet 17 is concentric to the first one. The two magnets are
• FIG. 10 A further embodiment of the invention is illustrated in Fig. 10.
• This embodiment incorporates a cylinder that has an elongated slot 18
• FIG. 11 A further embodiment of the invention is illustrated in Fig. 11.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11066961

Family Applications (1)

Country Status (4)

Cited By (7)

Citations (11)

Family Cites Families (2)

• 1995
  • 1995-01-02 IL IL11221895A patent/IL112218A0/xx unknown
  • 1995-12-28 EP EP95944538A patent/EP0847533A1/en not_active Withdrawn
  • 1995-12-28 WO PCT/US1995/016908 patent/WO1996021159A1/en not_active Application Discontinuation
  • 1995-12-28 AU AU46892/96A patent/AU4689296A/en not_active Abandoned

Patent Citations (11)

Non-Patent Citations (1)

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