US3498138A - Accelerometer - Google Patents

Accelerometer Download PDF

Info

Publication number
US3498138A
US3498138A US578172A US3498138DA US3498138A US 3498138 A US3498138 A US 3498138A US 578172 A US578172 A US 578172A US 3498138D A US3498138D A US 3498138DA US 3498138 A US3498138 A US 3498138A
Authority
US
United States
Prior art keywords
magnet
hinge
sensing
permanent magnet
acceleration
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
US578172A
Other languages
English (en)
Inventor
Robert E Stewart
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.)
Northrop Grumman Guidance and Electronics Co Inc
Original Assignee
Litton Systems Inc
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 Litton Systems Inc filed Critical Litton Systems Inc
Application granted granted Critical
Publication of US3498138A publication Critical patent/US3498138A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
    • G01P15/02—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses
    • G01P15/08—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values
    • G01P15/13—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by measuring the force required to restore a proofmass subjected to inertial forces to a null position
    • G01P15/132—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by making use of inertia forces using solid seismic masses with conversion into electric or magnetic values by measuring the force required to restore a proofmass subjected to inertial forces to a null position with electromagnetic counterbalancing means
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R17/00—Measuring arrangements involving comparison with a reference value, e.g. bridge
    • G01R17/02—Arrangements in which the value to be measured is automatically compared with a reference value
    • G01R17/06—Automatic balancing arrangements
    • G01R17/08—Automatic balancing arrangements in which a force or torque representing the measured value is balanced by a force or torque representing the reference value

Definitions

  • a servo system for positioning the exterior portion to a neutral position includes magnetic means for super-imposing a permanent magnets unidirectional field with a field produced by an electromagnet, to apply a restoring torquing force couple to the sensing member. Means are provided for varying the working air gap of the permanent magnet circuit to compensate for changes in the characteristics of the magnet due to temperature variations.
  • This invention pertains to an accelerometer, and more particularly to an accelerometer in which the sensing mass is servoed into a neutral position.
  • the state of the accelerometer art is represented by the device shown and described in US. Patent No. 3,229,530 issued Jan. 18, 1966 to D. E. Wilcox et al.
  • the sensing mass of the device of that patent is cantilevered on a flexible hinge relative to a supporting body whose acceleration is to be measured.
  • accelerations change the characteristic of the hinge member material in a non-linear manner, thereby changing the scale factor of the accelerometer.
  • accelerations perpendicular to the sensing axis of the accelerometer tend to unbalance the accelerometer and indicate an acceleration along the sensing axis.
  • those efiects are eliminated.
  • the device contemplated by this invention supports the angularly rotatable deflectable sensing member on flexible beams which are oppositely sprung so that the non-linear changes in characteristics are compensated.
  • the sensing mass is translated relative to the magnetic forcer, whereby at least a pair of opposing magnetic fields are required to ensure linearity between the restoring force and the current in the coil of the magnetic forcers.
  • the device contemplated by this invention uses an electromagnet coil and a permanent magnet which are arranged so that the magnetic field of the electromagnet coil and the magnetic field of the permanent magnet are maintained at right angles to each other to apply a pure torque to the sensing mass, whereby only one magnet system is required to generate a linear relation between the current applied to the restoring electromagnet coil and the restoring torque.
  • the device contemplated by this invention uses a novel "ice magnetic return path in which the working air gap in the permanent magnet circuit is varied with temperature to compensate for changes in the magnetic characteristics of the permanent magnet.
  • the device of this invention uses a ceramic wafer which is divided into two portions, one of which is attached to the housing of the accelerometer and the other forming the major portion of the angularly deflectable member.
  • Capacitors or pick-off plates for sensing angular deflection of the deflectable portion relative to the housing fixed portion are formed in a film on the surface of the deflectable portion. Electrical connections are made between the deflectable and housing fixed portions through a pair of conductive hinge elements.
  • said return path in a fashion to modify the width of the gap between said magnet and said return path to maintain the magnetic field strengths within said gap substantially constant over a wide temperature range.
  • FIGURES 1 and 2 are schematic diagrams, partly in section, of first and second embodiments of the angularly deflectable sensing element of the invention
  • FIGURE 3 is a plan view of an angularly deflectable sensing member and a housing-fixed member showing hinge-beams connecting the two members in a non-compensating manner;
  • FIGURE 4 is a plan view of an angularly deflectable sensing member and a housing-fixed member in which the hinge-beams connect the two members in a compensating manner;
  • FIGURE 5 is a sectional view taken at 55 in FIG- URES 3 and 4;
  • FIGURE 6 is a sectional view taken at 6-6 in FIG- URE 4;
  • FIGURE 7 is an oblique view, partly in section, of a typical device in accordance with this invention.
  • FIGURE 8 is a sectional view taken at 8-8 in FIG- URE 7;
  • FIGURES 9 and 10 are views taken at 9--9' and 10- 10 in FIGURE 8;
  • FIGURE 11 is a view taken at 11-11 in FIGURE 9;
  • FIGURE 12 is an expanded view of the hinge region between the angularly deflectable and housing-fixed members of the invention, taken at 12-12 in FIGURE 9;
  • FIGURE 13 is a view taken at 1313 in FIGURE 8.
  • FIGURE 14 is a typical schematic electrical diagram showing the interrelation between the angular displacement sensor and the electromagnetic torque-producing member.
  • FIGURES 1 and 2 are presented to demonstrate two preferred conditions of mass unbalance (eccentric weighting) of an angularly-defiectable-sensing member to adapt the deflectable member to sense accelerations in the directions indicated by arrows 20 and 26.
  • the entire deflectable portion of FIGURES 1 and 2 is adapted to tilt slightly about an axis 10.
  • Capacitance plates may be placed on the web 12 to be used, in conjunction with stationary plates, to sense angular displacement of the deflectable portion about the axis 10.
  • An electromagnet coil 14 may be attached to the edge of the web 12 and adapted to generate a magnetic field to interact with a second magnetic field which is generated by a permanent magnet (not shown) to restore the angular position of the device about axis 10 into a predetermined neutral position.
  • the center of gravity 16 is raised to a position directly above the axis of rotation 10 by the addition of appropriate symmetrical weights 18 to cause the device to be sensitive to accelerations in the direction shown by arrows 20.
  • a symmetrical ring or rim may extend around the entire periphery of the web 12.
  • a single unbalanced weight 22 is positioned on the edge of the web 12 to cause the center of gravity to move to a position 24 to cause the angularly deflectable portion to be sensitive to accelerations in the directions shown by arrow 26.
  • the entire device is free to deflect about axis 10 in response either to accelerations in the direction 20 (in FIG. 1) or accelerations in the direction 26 (in FIG. 2).
  • the deflecting of the device about axis 10' away from a neutral position is sensedfor exampleby means of a capacitance bridge with the plates of the capacitors (not shown) positioned on the web 12 and on the device whose acceleration is being sensed (not shown) to detect the angular displacement of the shown device away from its neutral or zero acceleration position.
  • the sensed displacement is then amplified and a current is supplied to the coil 14 to generate a magnetic field which interacts with the field of a permanent magnet to return and maintain the shown device in its neutral position.
  • the deflectable portion of FIGURES 1 and 2 may-for examplebe supported about axis 10 relative to a nondeflectable portion whose acceleration is being sensed, on low or non-friction bearings, on torsion pivots, or the like.
  • the device may be externally or internally supported, i.e. from a surrounding structure (not shown) or from an internal anchor (not shown in FIGURES 1 and 2, but shown in FIGURES 3 through 12).
  • FIGURES 5 and 6 are views taken at 55 and 6-6, respectively, in FIGURES 3 and 4, and are introduced for purposes of explaining the manner in which the configuration of FIGURE 4 excels the configuration of FIGURE 3.
  • the acceleration sensing member 30 is supported for limited angular rotation relative to housingfixed member 28 by a pair of flexible beams 32 and 34.
  • the beams 32 and 34 may be said to be sprung in the same direction, i.e. when deflected as shown in FIGURE 5, bias torques delivered by springs 32 and 34 are in the same direction, shown by arrow 36, thereby tending to tilt the angularly deflectable member 3 0 relative to the anchor member 28.
  • the acceleration sensing member 30 is supported for limited angular rotation, relative to housing-fixed member 28-, by a pair of beam springs 32 and 38 which are oppositely sprung, i.e. when angularly deflectable member 30 is deflected, spring 32 applies a bias torque in a first direction about the axis of relative rotation, as shown by arrow 36 in FIGURE 5, and spring 38 applies a bias torque in the opposite direction, as shown by arrow 40 in FIGURE 6.
  • the bias torques represented by arrows 36 and 40 cancel each other. It is this cancelling effect which is described herein when it is stated that the supporting beam-springs are oppositely sprung.
  • the members 28 and 30 are shown as ceramic-like members while the beam-springs 32, 34 and 38 are shown as metal beams.
  • the beam would be made of a metal such as electroless nickel which is bonded in a film to the surfaces of the ceramic members 28 and 30*.
  • FIGURES 7 through 13 The preferred embodiment of the invention is shown in FIGURES 7 through 13, with a circuit used with the invention shown in FIGURE 14.
  • the central housing-fixed member 42 is anchored between the top 43 and the bottom 44 of an outer housing 45 by means of an O-ring 46, a pressure ring 47, a wiring-harness ring 48, a permanent magnet member 50, and a magnet temperature compensating member 52.
  • the metal film sections which are bonded to the ceramic anchor member 42 at 54, 56, 58, 60, 62 and 64 on one surface and 66 on the other surface are used as electrical conductors. So, too, the conductive plating 68 on the surface of the magnet 50 is a conductive surface adapted to carry electrical potential from electrode 66 to the magnet 50.
  • the film '70 on the surface of member 52 is an insulating layer which may-for examplebe anodized aluminum.
  • a centering pin 72 and a centering collar 74 are used to center the various components, with the centering pin 72 recessed into the bottom 44 at 74 (FIG. 8).
  • the entire assembly is held in the outer housing 45 by a snap ring 76.
  • a magnet fluxreturn ring, or return path 78 surrounds magnet 50- and is held in place by magnet retaining member 52, as shown at 72 and 80 in FIG. 13. Space is made between magnet 50 and return path 78 to form a gap into which an electromagnet coil 82, atached to sensing mass 84 is inserted.
  • the sensing mass 84 has metal films 86, 87, 88 and 89 bonded to one surface and metal films 91, 92, 93 and 94 bonded to the other surface.
  • Films 92 and 93 bridge the radial hinge gap 96 at '97 and 98, and are attached to housing fixed member 42.
  • Films 91 and 94 bridge the radial hinge gap 100 at 101 and 102 and are attached to housing-fixed member 42.
  • the beams formed at 97, 98, 101 and 102 by films 92, 93, 91 and 94 form hinges between the angularly deflectable member 84 and the housing-fixed member 42 to allow limited rotation of rotator 84 about an axis of rotation 170 formed by these hinges.
  • the housing-fixed member 42 and the deflectable member 84 are fabricated from a piece of ceramic material and the conducting films on the two surfaces thereof are fabricated of electroless nickel.
  • the outer edge of the sensing member 84 the arcuate groves 104, 106, and the radial hinge grooves 96 and 100 are first cut out of the blank.
  • the cutting may befor exampleby ultrasonic means, such as by a Cavitron.
  • Copper is then plated into the slots or grooves by using first a flash of electroless copper than electroforming the copper into the grooves to completely fill the grooves. The copper is then lapped flush with the faces of the base ceramic material.
  • Electroless nickel is then plated onto the faces of the blank comprising the members 42 and 84, and the copper material filling the gaps 104, 106, 96 and 100.
  • a photoresistive material is than applied to the nickel in a predetermined pattern to define the electrodes and the hinge beams which are shown particularly in FIGURES 9 and 10.
  • the nickel is then deplated or etched with the photo-resistive material resisting the deplating or etching process at the places where it is desired to leave the electroless nickel.
  • the material is then etchedfor example-with hot chromic acid, or the like, to remove the copper material from the grooves 96, 100, 104 and 106.
  • FIGURE 8 feeding through the top 43 of the housing, six insulated conducting pins, two of which are shown in FIGURE 8 and five of which are shown in FIGURE 7 at 124, 126, 128, 130 and 132.
  • Each of the conducting pins connects to a separate conducting buss of the wiring harness ring 48.
  • Typical conducting busses are shown in FIGURES 7 and 8 at 134 and 136.
  • the various busses carry electrical voltage and/or current to or from the conductive films 54, 85, 60, 62, and 64. Voltage applied to the pin connected to film 62 is conducted through the conducting member 114 to film 66 which is in contact (see FIG. 8) with film 68. Film 68 is electrically in contact with the magnet 50.
  • Voltage applied to film 64 is carried through a conducting member 116 to conducting film 93 which act as one capacitor plate for the pick off for detecting the displacement of member 84.
  • Voltage applied to film 58 is carried through conducting member 112 to conducting film 91 which acts as a second capacitor plate for the pick off of member 84.
  • Magnet current is carried from conducting film 54, through conductive member 118, across gap 96 on conducting hinge member and film 97, through conducting member 120, through conducting film 89, through wire 122 to coil 82. The current is returned from magnet coil 82 through a conductor (not shown) to conductive film 87, through conductive member 108, through film 94, across gap 100, through conductive member 110, and through conductive film 60.
  • an unbalanced weight is placed on one side at to cause the deflectable member 84 to sense accelerations in the fashion described in connection with the device of FIGURE 2.
  • the weight 150 could be extended completely around the outer periphery of member 84, or an additional Weight could be placed diametrically opposite the position of balance weight 150.
  • the mass of the member 84 could be adjusted to achieve the desired result by distributing the masses to create the desired amount and position of mass unbalance.
  • a pair of stops 152 and 154 are placed on the top of the magnet 50 to snub the member 84, should it angularly displace through that distance.
  • FIGURE 14 is a typical electrical circuit which is adapted to sense the angular displacement of member 84 and to apply restoring current to the torquing coil 82.
  • the capacitors 156 and 158 are part of the mechanism itself. The common plate of the two capacitors is the surface of the magnet 50. The other two plates are the films 91 and 93. Electrical connection to magnet 50 and to films 91 and 93 has been described above. The remaining electrical components are external to the housing 45.
  • Capacitors 156 and 158 together with resistors 160 and 162 form a Wheatstone Bridge, the input of which is connected to a source of alternating current 164, and the output of which is connected to the input of a balanced differential amplifier 166. The output of amplifier 166 is connected through a demodulator 168 to the torquing coil 82.
  • the connections to the torquing coil 82 through certain films on the member 42 and the member 84 have been described.
  • the interior of the housing is filledfor examplewith a gas such as dry nitrogen.
  • a gas such as dry nitrogen.
  • the movable member 84 is damped by the cushion of gas squeezed between the member 84 and the top of the magnet 50.
  • the damping is symmetrical to cause both sides of the member 84 to clamp equally deflections in either direction.
  • the separation slot between members 84 and 42 are formed by a pair of hinge slots 96 and 100 which are radially directed in opposite directions along a common diameter.
  • the separation slot 106 is an arcuate slot which connects the radially outward end of slot 96 to the radially inward end of slot 100.
  • Separation slot 104 is an arcuate slot which connects the radially outward end of slot 100 to the radically inward end of slot 96.
  • Plate 86 and 88 are present to oppose distortions which might result in member 84 from differential expansion between plates 91 and 93 and member 84.
  • the magnet 50 is shown as an annular shaped member, and is fabricated-for exampleof an aluminum nickel alloy such as Alnico, in which north and south poles appear at opposite ends of a preferred diameter because of the processing of the magnet in the presence of a magnet field.
  • the diameter defining the north and south poles is positioned at right angles to the hinge line 170 between the member 84 and the member 42,
  • the extreme ends of the section of magnet 50 in sectional view of FIG- URE 8 is substantially along the diameter between the north and south poles of the magnet 50.
  • the return path for the magnetic field generated by the magnet 50 is through the gap in which electromagnetic coil 82 is positioned and through the flux ring 78.
  • the magnet field direction of the permanent magnet within the gap between the magnet 50 and the return of the flux ring 78 is in a direction across the diameter of the magnet 50, between the north and south poles.
  • the magnet field generated by the current in the electromagnetic coil 82 is perpendicular to that line and to the hinge line 170, thereby generating a maximum amount of torque by interaction between the two magnetic fields for a given amount of applied current, the torque (at least for the small angles involved) being precisely linear with the amount of current applied to the electromagnet coil 82.
  • the magnetic field strength of the permanent magnet tends to decrease as the temperature increases.
  • the gap is varied inversely with the temerature, i.e. as the temperature increases the gap is reduced, and as the temperature decreases the gap is increase-d, along the axis between the north and south poles of the magnet.
  • the temperature compensation is accomplished in this invention by means of a magnet compensation member 52.
  • the member 52 mayfor example-be fabricated of aluminum with the anodized surface 70 acting as an electrical insulator between the aluminum and the magnet.
  • Two bearing members 79 and 80 contact the flux ring 78 symmetrically on an axis perpendicular to the axis between the north and south poles of the magnet '0 and parallel to the hinge axis 170, as shown in FIGURE 13.
  • the member 52 expands, whereby the bearing members 79 and 80 elongate the axis of the flux ring 78 in the direction parallel to axis 170, as shown by the dash line at 180.
  • Extension of the axis of flux ring 78 in a direction along the axis 170 decreases the diameter of the flux ring in the direction perpendicular to axis 170 and parallel to the diameter of magnet 50 between the north and south poles, as shown by the dashed line at 182.
  • the gap between the magnet 50 and the flux ring 78 in the region,of the north and south poles of the magnet 50 is decreased, thereby compensating for a decrease in the magnetization of the permanent magnet caused by increased temperatures.
  • the device shown in FIGURES 7 through 14 senses acceleration in the direction indicated by arrow 200 in FIGURE 8.
  • the current amplitude applied to torquing coil 82 is a measureof the amplitude of the applied acceleration, and the direction of current is a measure of the sense of the applied acceleration.
  • member 84 is weighted in the manner shown in FIGURE 1, acceleration in the direction of arrow 200 tends to translate member 84 slightly from its no-acceleration position.
  • the translation of member 84 is not sensed by the circuit of FIGURE 14 because the capacitors 156 and 158 are not unbalanced by the translation.
  • the member 84 is oppositely sprung relative to the member 42 in a fashion similar to that shown and described in connection with the device of FIGURE 4, the translation of the member 84 does not introduce a net torque about the axis 170.
  • the restoring torque caused by the. interaction between the magnetic fields of electromagnet 82 and permanent magnet 50 is a pure torque.
  • the current applied to magnet 82 is linearly related to the restoring torque because the field of the electromagnet 82 is maintained at right angles to the field of the permanent magnet 50.
  • the structure of the member 84 and the member 42 are relatively inexpensive to manufacture and, in fact can be manufac ured in m ss. p oduc ion with extreme accuracy because of the process of manufacture which is described herein.
  • the device of this invention is a very compact, and relatively inexpensive, accelerometer having extreme precision over relatively wide temperature ranges, in which the relation between the applied acceleration and the restoring current is exceptionally linear.
  • a device for sensing acceleration comprising:
  • an acceleration sensing member having separate radially exterior and radially interior portions joined by at least a pair of flexible hinge members, and supported in said housing for rotation of one of said portions relative to the other portion about a hinge line which passes through a central section of said radially interior portion, said one portion being eccentrically weighted;
  • a capacitance pick-off including capacitance plates on said one rotatable portion of said sensing member, for detecting rotation of said one rotatable portion about said hinge line;
  • electromagnet means carried by said rotatable portion
  • hinge members are aflixed to opposite radial sides of the interior portion of said sensing member; whereby when said rotatable portion is translated, said hinge members apply restoring forces tending to result in only translational displacement of the rotatable portion.
  • a magnetic flux ring associated with said permanent and electromagnets, positioned to create a working gap in the field of said permanent magnet into which the coil of said electromagnet is inserted.
  • temperature responsive forcing means engaging said magnetic flux ring to vary the width of said working gap in response to changes in temperature.
  • sensing member comprises a ceramic wafer having thin metallic films on the face thereof to form capacitance plates for said pick-off and to form hinge members connecting a housing-fixed ceramic portion and said movable portion.
  • sensing member comprises a ceramic wafer having thin metallic films on the face thereof to form capacitance plates for said pick-off and to form hinge members connecting a housing-fixed ceramic portion and said movable portion.
  • hinge members are beam springs.
  • a device as recited in claim 7 adapted to provide an output signal which is a function of said acceleration and in which said beam springs are affixed to opposite radial sides, on opposite ends of said interior portion of said sensing member.
  • a device for sensing acceleration comprising:
  • a substantially circular non-conducting wafer divided into two portions, a radially exterior portion and a radially interior portion, by a dividing slot formed in said Wafer, said slot being defined by a pair of hinge slots which are radially directed along opposite radii of the same diameter and each extending from a first radius to a second radius of the circular shape of said wafer and by a pair of substantially identical arcuate separation slots symmetrically disposed on said wafer connecting the outer end of said first hinge slot to the inner end of said second hinge slot and the outer end of said second hinge slot to the inner end of said first hinge slot;
  • a housing attached to said inner portion and enclosing said inner and outer portions
  • a device as recited in claim 10 in which said beam springs are afiixed to opposite radial sides on opposite ends of said inner portion, whereby when said outer portion is translated said hinge members apply restoring forces tending to produce only translational displacement of said outer portion.
  • said magnetic means includes a plate shaped permanent magnet having its axis of magnetism extending transversely therethrough; and an electromagnet coil attached to said outer portion and encompassing said permanent magnet so as to extend into the field of said permanent magnet; whereby the coil, upon being energized, produces a magnetic field which interacts with the unidirectional field of the permanent magnet so that forces, experienced on opposite sides of the coil, are oriented in opposite directions and the two magnetic fields cooperate to apply restoring torquing forces to said outer portion.
  • said sensing means includes at least two substantially identical electrical capacitance plates formed on said outer portion symmetrically displaced with respect to the hinge line of said hinge members and said hinge slots; and stationary capacitor plates, adjacent to said capacitance plates formed on said outer portion; and
  • said electrical means is connected between said capacitance plates and said electromagnet coil to cause said electromagnet coil to generate a magnetic field in response to deflection of said outer portion relative to said inner portion to hold said outer portion at a predetermined angular neutral position.
  • said permanent magnet means is a substantially circular metallic disc permanent magnet attached to said housing and having its face substantially parallel to the capacitive plates upon said outer portion when said outer portion is in its neutral position, the face of said electromagnet forming a housing-fixed electrode, and a ferromagnetic flux return member for conducting a magnetic flux between the poles of said permanent magnet externally to said permanent magnet;
  • said electromagnet coil is positioned in a gap between said flux return member and said permanent magnet.
  • a device as recited in claim 14 in which said flux return member is a flux ring; and further comprising a temperature sensitive member, bearing against said flux ring, adapted to deform said flux ring in response to temperature changes to vary the gap between said flux ring and said permanent magnet in the region of the poles of said permanent magnet.
  • thermosensitive member is centered on said alignment pin and has radial projections therefrom, bearing against said flux ring along the hinge line of said hinge members to shorten the gap between said flux ring and said permanent magnet on an axis in the plane of said permanent magnet and perpendicular to said hinge line.
  • a device as recited in claim 17 in which said temperature sensitive member is made of aluminum and formed into a disc having bearing projections thereform, contacting said flux ring along said hinge line.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Gyroscopes (AREA)
  • Indication And Recording Devices For Special Purposes And Tariff Metering Devices (AREA)
  • Reciprocating, Oscillating Or Vibrating Motors (AREA)
US578172A 1966-09-09 1966-09-09 Accelerometer Expired - Lifetime US3498138A (en)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
US57817266A 1966-09-09 1966-09-09
GB42892/67A GB1163209A (en) 1966-09-09 1967-09-20 Accelerometer
GB57688/68A GB1163210A (en) 1966-09-09 1967-09-20 Temperature compensating of Electromagnetic systems of Measuring Instruments
DEL0057481 1967-09-23
NL6713054A NL6713054A (it) 1966-09-09 1967-09-25
FR122705A FR1538245A (fr) 1966-09-09 1967-09-28 Accéléromètre
NL7212862.A NL158616B (nl) 1966-09-09 1972-09-22 Temperatuurgecompenseerd, elektromagnetisch werkend meetinstrument.

Publications (1)

Publication Number Publication Date
US3498138A true US3498138A (en) 1970-03-03

Family

ID=27561665

Family Applications (1)

Application Number Title Priority Date Filing Date
US578172A Expired - Lifetime US3498138A (en) 1966-09-09 1966-09-09 Accelerometer

Country Status (6)

Country Link
US (1) US3498138A (it)
BE (1) BE704569A (it)
DE (1) DE1673402B1 (it)
FR (1) FR1538245A (it)
GB (2) GB1163209A (it)
NL (3) NL6713054A (it)

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0041187A2 (en) * 1980-06-04 1981-12-09 Ford-Werke Aktiengesellschaft Automatic transmission governor having deceleration sensitive pressure switching feature
US4338819A (en) * 1980-09-08 1982-07-13 Systron-Donner Corporation Accelerometer including an overall arrangement for reducing temperature related errors
FR2509866A1 (fr) * 1981-07-14 1983-01-21 Sundstrand Data Control Procede de fabrication d'une articulation a flexion pour un transducteur de force
FR2509864A1 (fr) * 1981-07-14 1983-01-21 Sundstrand Data Control Articulation a flexion pour un transducteur de force
FR2509865A1 (fr) * 1981-07-14 1983-01-21 Sundstrand Data Control Articulation a flexion et transducteur l'utilisant
FR2509863A1 (fr) * 1981-07-14 1983-01-21 Sundstrand Data Control Structure d'articulation a flexion pour un transducteur de force
US4699006A (en) * 1984-03-19 1987-10-13 The Charles Stark Draper Laboratory, Inc. Vibratory digital integrating accelerometer
WO1988000350A1 (en) * 1986-06-27 1988-01-14 Sundstrand Data Control, Inc. Translational accelerometer and accelerometer assembly method
US4736629A (en) * 1985-12-20 1988-04-12 Silicon Designs, Inc. Micro-miniature accelerometer
US4872342A (en) * 1986-06-27 1989-10-10 Sundstrand Data Control, Inc. Translational accelerometer and accelerometer assembly method
US4987780A (en) * 1987-11-16 1991-01-29 Litton Systems, Inc. Integrated accelerometer assembly
US5109693A (en) * 1989-05-29 1992-05-05 Tokyo Keiki Co., Ltd. Thermally stabilized accelerometer
US5220835A (en) * 1991-09-12 1993-06-22 Ford Motor Company Torsion beam accelerometer
US5249465A (en) * 1990-12-11 1993-10-05 Motorola, Inc. Accelerometer utilizing an annular mass
US5253526A (en) * 1990-05-30 1993-10-19 Copal Company Limited Capacitive acceleration sensor with free diaphragm
US5404749A (en) * 1993-04-07 1995-04-11 Ford Motor Company Boron doped silicon accelerometer sense element
US5600067A (en) * 1993-08-18 1997-02-04 Alliedsignal, Inc. Torque wire thermal strain relief
US5610335A (en) * 1993-05-26 1997-03-11 Cornell Research Foundation Microelectromechanical lateral accelerometer
US5640133A (en) * 1995-06-23 1997-06-17 Cornell Research Foundation, Inc. Capacitance based tunable micromechanical resonators
US5644086A (en) * 1996-10-08 1997-07-01 Tokyo Gas Co., Ltd. Preloaded linear beam vibration sensor
US5914553A (en) * 1997-06-16 1999-06-22 Cornell Research Foundation, Inc. Multistable tunable micromechanical resonators
US5978972A (en) * 1996-06-14 1999-11-09 Johns Hopkins University Helmet system including at least three accelerometers and mass memory and method for recording in real-time orthogonal acceleration data of a head
US6170332B1 (en) 1993-05-26 2001-01-09 Cornell Research Foundation, Inc. Micromechanical accelerometer for automotive applications
US10180445B2 (en) 2016-06-08 2019-01-15 Honeywell International Inc. Reducing bias in an accelerometer via current adjustment

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4182187A (en) * 1978-04-24 1980-01-08 Sundstrand Data Control, Inc. Force balancing assembly for transducers
DE3625411A1 (de) * 1986-07-26 1988-02-04 Messerschmitt Boelkow Blohm Kapazitiver beschleunigungssensor
CN112798993B (zh) * 2021-04-08 2021-07-13 中国电子科技集团公司第九研究所 基于加速度计测量永磁材料温度系数的装置及测量方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2959459A (en) * 1953-08-04 1960-11-08 James J Ryan Flight recorder
US3339419A (en) * 1964-07-02 1967-09-05 North American Aviation Inc Accelerometer

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB783104A (en) * 1955-01-13 1957-09-18 Mini Of Supply Improvements in accelerometers

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2959459A (en) * 1953-08-04 1960-11-08 James J Ryan Flight recorder
US3339419A (en) * 1964-07-02 1967-09-05 North American Aviation Inc Accelerometer

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0041187A2 (en) * 1980-06-04 1981-12-09 Ford-Werke Aktiengesellschaft Automatic transmission governor having deceleration sensitive pressure switching feature
EP0041187A3 (en) * 1980-06-04 1983-01-12 Ford-Werke Aktiengesellschaft Automatic transmission governor having deceleration sensitive pressure switching feature
US4338819A (en) * 1980-09-08 1982-07-13 Systron-Donner Corporation Accelerometer including an overall arrangement for reducing temperature related errors
FR2509866A1 (fr) * 1981-07-14 1983-01-21 Sundstrand Data Control Procede de fabrication d'une articulation a flexion pour un transducteur de force
FR2509864A1 (fr) * 1981-07-14 1983-01-21 Sundstrand Data Control Articulation a flexion pour un transducteur de force
FR2509865A1 (fr) * 1981-07-14 1983-01-21 Sundstrand Data Control Articulation a flexion et transducteur l'utilisant
FR2509863A1 (fr) * 1981-07-14 1983-01-21 Sundstrand Data Control Structure d'articulation a flexion pour un transducteur de force
US4699006A (en) * 1984-03-19 1987-10-13 The Charles Stark Draper Laboratory, Inc. Vibratory digital integrating accelerometer
US4736629A (en) * 1985-12-20 1988-04-12 Silicon Designs, Inc. Micro-miniature accelerometer
WO1988000350A1 (en) * 1986-06-27 1988-01-14 Sundstrand Data Control, Inc. Translational accelerometer and accelerometer assembly method
US4872342A (en) * 1986-06-27 1989-10-10 Sundstrand Data Control, Inc. Translational accelerometer and accelerometer assembly method
US4987780A (en) * 1987-11-16 1991-01-29 Litton Systems, Inc. Integrated accelerometer assembly
US5109693A (en) * 1989-05-29 1992-05-05 Tokyo Keiki Co., Ltd. Thermally stabilized accelerometer
US5253526A (en) * 1990-05-30 1993-10-19 Copal Company Limited Capacitive acceleration sensor with free diaphragm
US5249465A (en) * 1990-12-11 1993-10-05 Motorola, Inc. Accelerometer utilizing an annular mass
US5220835A (en) * 1991-09-12 1993-06-22 Ford Motor Company Torsion beam accelerometer
US5404749A (en) * 1993-04-07 1995-04-11 Ford Motor Company Boron doped silicon accelerometer sense element
US6170332B1 (en) 1993-05-26 2001-01-09 Cornell Research Foundation, Inc. Micromechanical accelerometer for automotive applications
US5610335A (en) * 1993-05-26 1997-03-11 Cornell Research Foundation Microelectromechanical lateral accelerometer
US6199874B1 (en) 1993-05-26 2001-03-13 Cornell Research Foundation Inc. Microelectromechanical accelerometer for automotive applications
US5600067A (en) * 1993-08-18 1997-02-04 Alliedsignal, Inc. Torque wire thermal strain relief
US5640133A (en) * 1995-06-23 1997-06-17 Cornell Research Foundation, Inc. Capacitance based tunable micromechanical resonators
US5978972A (en) * 1996-06-14 1999-11-09 Johns Hopkins University Helmet system including at least three accelerometers and mass memory and method for recording in real-time orthogonal acceleration data of a head
US5644086A (en) * 1996-10-08 1997-07-01 Tokyo Gas Co., Ltd. Preloaded linear beam vibration sensor
US5914553A (en) * 1997-06-16 1999-06-22 Cornell Research Foundation, Inc. Multistable tunable micromechanical resonators
US10180445B2 (en) 2016-06-08 2019-01-15 Honeywell International Inc. Reducing bias in an accelerometer via current adjustment

Also Published As

Publication number Publication date
NL158616B (nl) 1978-11-15
GB1163209A (en) 1969-09-04
NL6713054A (it) 1969-03-27
DE1673402B1 (de) 1970-12-03
FR1538245A (fr) 1968-08-30
NL7212862A (it) 1972-12-27
BE704569A (it) 1968-04-02
GB1163210A (en) 1969-09-04
NL136155C (it)

Similar Documents

Publication Publication Date Title
US3498138A (en) Accelerometer
KR920004768B1 (ko) 가속도 센서
EP0323709B1 (en) Tri-axial accelerometers
US5205171A (en) Miniature silicon accelerometer and method
US4711128A (en) Micromachined accelerometer with electrostatic return
US5085079A (en) Accelerometer with mounting/coupling structure for an electronics assembly
US4498342A (en) Integrated silicon accelerometer with stress-free rebalancing
US3559492A (en) Two-axes angular rate and linear acceleration multisensor
US4344004A (en) Dual function transducer utilizing displacement currents
US4398417A (en) Three-axis accelerometer having flexure bearing with overload protection
RU2155964C1 (ru) Компенсационный маятниковый акселерометр
US3513711A (en) Subminiature single axis accelerometer
US4706498A (en) Apparatus and method for measuring movement
GB2162317A (en) Accelerometer
US4414848A (en) Three-axis accelerometer
US2888256A (en) Accelerometers
US4088027A (en) Force balance servo accelerometer
JPS5952365B2 (ja) 角度測定又は加速度測定に使用できる測定装置
US4372162A (en) Three-axis accelerometer having dynamic bias compensation
US5090243A (en) Preload system for accelerometer
US4372520A (en) Suspension for three-axis accelerometer
US3331253A (en) Accelerometer and sensing assembly therefor
RU2291450C1 (ru) Компенсационный маятниковый акселерометр
US4145929A (en) Linear accelerometer with improved magnetic rebalance system
US3680392A (en) Three-axis accelerometer