Patents Represented by Law Firm Adduci, Mastriani, & Schaumberg
  • Patent number: 7197951
    Abstract: A rotation angle sensor includes: (a) a multi-resolver housing with a high precision structure; (b) stator terminals that do not cause deformation or loosening of terminal pins from the substrates to which they are attached; and (3) a signal line connection structure that is not affected by thermal stress. The housing (10) includes divisional housings (10a, 10b), and one resolver is installed in each of the divisional housings (10a, 10b). The divisional housings (10a, 10b) are assembled by aligning respective openings therein in an axial direction. The lead lines of stator windings are connected to printed circuit substrates (51) installed on insulators (20a, 20b), and pins (54) connect the printed circuit substrates (51) to a connecting signal output line via flexible connectors (61, 64).
    Type: Grant
    Filed: July 23, 2004
    Date of Patent: April 3, 2007
    Assignee: Minebea Co., Ltd.
    Inventors: Toshisada Koyama, Mutsumi Matsuura, Takashi Sano, Yoshihito Osanai
  • Patent number: 7157906
    Abstract: A double variable reluctance resolver in which a redundancy is given to a variable reluctance resolver to improve reliability. The double variable reluctance resolver also functions as a multiple speed resolver system.
    Type: Grant
    Filed: April 27, 2004
    Date of Patent: January 2, 2007
    Assignee: Minebea Co., Ltd.
    Inventor: Taiichi Miya
  • Patent number: 7148599
    Abstract: An iron core winding is such that a winding of a given polarity is coiled in series so that the beginning of each coiling and the ending of each coiling cross on a magnetic pole that is positioned in the direction of a circumference of the iron core. When the winding of the magnetic core with the given polarity is completed, the winding direction is reversed and the remainder of the winding, which has the opposite polarity, is coiled in series so that the beginning of each coiling and the ending of each coiling cross in the reversed direction. A variable reluctance angle detector uses the iron core winding. The number of windings of the output winding is the same for each pole, and an induced voltage output of a sine wave is obtained.
    Type: Grant
    Filed: February 18, 2004
    Date of Patent: December 12, 2006
    Assignee: Minebea Co., Ltd.
    Inventors: Naohiko Aoyama, Hiroyuki Kujirai
  • Patent number: 7135860
    Abstract: A variable reluctance resolver has a rotor with magnetic poles with 2× or greater axis combination angles, and is structured so that reliable and accurate zero point detection can be carried out. Concave and convex portions are provided on at least two, but fewer than all, of the magnetic poles of the rotor, and the zero point detection winding is provided on a plurality of electrical poles of the stator. Two or more zero point detection signals are generated simultaneously by a plurality of zero point detection windings. Therefore, even if a portion of the zero point detection signals is lost, the zero point can still be identified based on the correlation between the two or more zero point detection signals.
    Type: Grant
    Filed: July 29, 2004
    Date of Patent: November 14, 2006
    Assignee: Minebea Co., Ltd.
    Inventors: Taiichi Miya, Taro Kasahara, Toshisada Koyama
  • Patent number: 7119717
    Abstract: A Resolver/Digital (R/D) converter includes an encoder output divider having a DSP generating 14-bit encoded signals A2 and B2 from a timing analysis performed during the first period of 12-bit encoded signal A1. The DSP generates a selection signal output to a multiplexer to select encoded signals A1 and BE1 or encoded signals A2 and B2 depending on the rotational speed of the rotor of a resolver. Based on the selection signal, the multiplexer outputs 12-bit encoded signals A1 and B1 when the rotational speed is less than 400 rpm or greater than 1200 rpm, and outputs 14-bit encoded signals A2 and B2 when rotational speed is between 400 rpm and 1200 rpm.
    Type: Grant
    Filed: March 30, 2004
    Date of Patent: October 10, 2006
    Assignee: Minebea Co., Ltd.
    Inventor: Takao Takehara
  • Patent number: 7044005
    Abstract: A rotation angle sensor and a method of winding a rotation angle sensor involve a single electrical wire that is wound from a rotor transformer to a magnetic rotor. The magnetic rotor is axially spaced on a shaft from the rotor transformer. A notch is formed in a wall of a bobbin of the rotor transformer to permit the wire to pass from the rotor transformer to the magnetic rotor. The ends of the single wire are electrically connected together at a junction, and the junction is fixed to the rotor transformer with resin.
    Type: Grant
    Filed: July 16, 2004
    Date of Patent: May 16, 2006
    Assignee: Minebea Co., Ltd.
    Inventors: Toshisada Koyama, Mutsumi Matsuura, Takashi Sano
  • Patent number: 7015840
    Abstract: An R/D converter allows high precision detection of a rotation angle of a rotor axis of a resolver having high rates of rotation. An A/D converter is built into a digital signal processor and converts a sine wave and cosine wave output from the resolver. An axis angle calculator calculates tan ?=A((sin ?t)(sin ?))/A((sin ?t)(cos ?)) from A(sin ?t)(sin ?) and A(sin ?t)(cos ?) and further calculates ?=tan?1 ?. The angle space is divided into quadrants and an offset value is set for each quadrant and by adding or subtracting the calculated ? to or from the offset value to form the final angle of the rotor axis of the resolver.
    Type: Grant
    Filed: March 4, 2004
    Date of Patent: March 21, 2006
    Assignee: Minebea Co., Ltd.
    Inventor: Takao Takehara
  • Patent number: 7009385
    Abstract: A flux compensated rotational position detector includes a rotating element having a plurality of magnetic poles extending over its entire periphery, and a fixed element having a plurality of protruding fixed-element magnetic poles with fixed-element magnetic pole teeth opposing the rotating element, and first and second compensating poles disposed on either side of the fixed-element magnetic poles, the first and second compensating poles having respective first and second magnetic pole teeth opposing the rotating element, wherein the fixed element does not form a closed magnetic path around the entire periphery of the rotating element, magnetizing windings are provided on all of the first and second compensating poles and the fixed-element magnetic poles, and sine output and cosine output windings are provided on each of the fixed element magnetic poles. Methods for operating the detector are also described.
    Type: Grant
    Filed: March 26, 2003
    Date of Patent: March 7, 2006
    Assignee: Minebea Co., Ltd.
    Inventors: Masahiro Kobayashi, Hiroyuki Kujirai
  • Patent number: 7005813
    Abstract: A booster circuit for a pre-drive circuit of a brushless direct current single-phase motor. When a series pair of power FETs of the drive circuit turn on, one boost control switching element of the pre-drive circuit turns on, another series pair of power FETs of the drive circuit turn off, and the other boost control switching element of the pre-drive circuit turns off. The booster circuit provides a continuous stable output voltage to the motor.
    Type: Grant
    Filed: November 24, 2003
    Date of Patent: February 28, 2006
    Assignee: Minebea Co., Ltd.
    Inventor: Junnan Xi
  • Patent number: 7005824
    Abstract: A shutter mechanism includes a drum (2), a stepping motor (5), a driver (20), a microcomputer (10), a memory (16), and a load magnitude detection circuit (30) that detects the magnitude of the load on the stepping motor (5) when an object such as a shutter (3) is either wound or unwound from the drum (2). The microcomputer (10) can set the upper and lower limit stopping positions of the shutter (3) by resetting the number of command pulses stored in the memory (16) when the load magnitude detection circuit (30) detects an increase in the load at the stepping motor (5), and storing the number of command pulses output to that point from the memory (16) when the load magnitude detection circuit (30) next detects an increase in the load at the stepping motor (5) after the outputting of the command pulses is next restarted.
    Type: Grant
    Filed: December 18, 2003
    Date of Patent: February 28, 2006
    Assignee: Minebea Co., Ltd.
    Inventor: Naotaka Akiwa
  • Patent number: 6968721
    Abstract: A method of manufacturing a turbine blade retainer using a material cutting device and a material bending device includes steps for suspending a bar stock material between a polyurethane shock absorber and a bore of a cutting jig support, moving the cutting punch downward to press the distal end of the bar stock material into the shock absorber and then cut the bar stock material to thereby generate a blank, clamping the blank between a bending punch and a receiving slide by pressing the bending punch against the receiving slide, bending the distal end of the blank against a chamfered section of a bending support in response to continued downward motion of the bending punch to thereby form a blade retainer precursor, and milling the blade retainer precursor to form the blade retainer. Corresponding devices for performing these steps are also described.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: November 29, 2005
    Assignee: Minebea Co., Ltd.
    Inventors: Kenjiro Tabuchi, Go Nabatame
  • Patent number: 6952152
    Abstract: A spacer 2 is provided between an inner core 62 and a resolver rotor 63, which are respectively attached to a rotary shaft 68. A cutout groove 42 is formed at a flange 41 of the inner core 62. A fixing groove 3 and the cutout groove 42 are aligned in the rotary shaft 68 direction. The rotary transformer output winding 65 and resolver excitation windings 64 are soldered and electrically connected by a crossover 60. The crossover 60 is covered with an insulating tube 6. The crossover 60 is fitted into the fixing groove 3. The fixing groove 3 and an inter-magnet space 631 are misaligned in the circumferential direction of the rotor 63. Thus, a frictional force is applied between the insulating tube 6 and the fixing groove 3, which secures the crossover 60 and prevents the crossover 60 from escaping from the fixing groove 3.
    Type: Grant
    Filed: October 9, 2003
    Date of Patent: October 4, 2005
    Assignee: Minebea Co., Ltd.
    Inventors: Taiichi Miya, Mutsumi Matsuura
  • Patent number: 6935194
    Abstract: A dual resolver device that includes a first resolver having a first rotary shaft, and a second resolver having a second rotary shaft, wherein the absolute value of a difference between a shaft angle multiple of the first resolver and a shaft angle multiple of the second resolver is 1. In one embodiment, the dual resolver device further includes a torsion bar connecting the first and second rotary shafts. In another embodiment, the first and second rotary shafts constitute different portions of the same rotary shaft. In either embodiment, the first resolver preferably produces an output indicative of a rotation angle of the first rotary shaft, and the second resolver preferably produces an output indicative of a rotation angle of the second rotary shaft. The dual resolver device preferably further includes a processor that determines an absolute shaft rotation angle in response to the first and second outputs, and the shaft angle multiples of the first and second resolvers.
    Type: Grant
    Filed: March 21, 2003
    Date of Patent: August 30, 2005
    Assignee: Minebea Co., Ltd.
    Inventors: Mutsumi Matsuura, Taiichi Miya
  • Patent number: 6912883
    Abstract: A thread rolling machine forming a threaded member from a workpiece includes a die, a device for rotating the die, a device for generating a load applied to the die in a workpiece-feeding direction, a member that deforms under the applied load during a thread rolling operation, a strain gauge that generates a signal indicative of the deformation of the member under the applied load, and a computer that calculates the load applied during thread rolling operation based on the signal generated by the strain gauge. The computer can generate a feedback signal permitting control of the applied load generated by the thread rolling machine by controlling either the load generating device or the die-rotating device. An operating method for a thread rolling machine is also described.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: July 5, 2005
    Assignee: Minebea Co., Ltd.
    Inventor: Takeshi Sakai
  • Patent number: 6894629
    Abstract: An A/D converter converts a sine and cosine wave output of a resolver to form a digital sine and cosine. A microcomputer uses an absolute value of digital sin ? as an address to retrieve ? from a memory containing angle values between 0° and 90°, if the absolute value of sin ? is between 0 and 0.707. Otherwise, if the absolute value of sin ? is between 0.707 and 1, cos ? is used as an address to retrieve ?. The polarities of sin ? and cos ? are used to determine a quadrant and an associated offset including 0°, 180°??, 180°+?, and 360°??, which is combined with ? such that the final angle of the rotor axis is obtained.
    Type: Grant
    Filed: March 4, 2004
    Date of Patent: May 17, 2005
    Assignee: Minebea Co., Ltd.
    Inventor: Takao Takehara
  • Patent number: 6891460
    Abstract: A rotor transformer positioning mechanism permitting automatic positioning of a rotor transformer, having a first winding, relative to a rotor stack, having a second winding, mounted on a common rotary shaft to thereby permit a crossover having a predetermined length to be installed between the first and second windings includes a crossover positioning cutout disposed in a first flange of the rotor transformer. In an exemplary case, the rotor transformer includes the first flange and a second flange disposed on opposite ends of the first coil, and the second flange is proximate to the crossover. A method of assembling a rotating machine using the rotor transformer positioning mechanism is also described.
    Type: Grant
    Filed: April 1, 2003
    Date of Patent: May 10, 2005
    Assignee: Minebea Co., Ltd.
    Inventors: Tsuneo Tezuka, Genta Yoshii
  • Patent number: 6876120
    Abstract: An inner core 62 and a resolver rotor 63 are secured to a rotary shaft 68 so that they are coaxial. A spacer 2, is provided between the inner core 62 and the resolver rotor 63. The spacer 2 and the inner core 62 are formed as a unit with separation, or space, between the spacer 2 and flange 41 of the inner core 62. The thickness of flange 41 is greater than the corresponding width of the corresponding part of the outer core, on which a rotary transformer input winding is wound. The resolver rotor 63 is a separate unit from the spacer 2 and the inner core 62, which facilitates automatic winding of the rotor. Grooves 3, 42 are formed in the spacer 2 and the flange 41 to accommodate a crossover wire 60.
    Type: Grant
    Filed: October 9, 2003
    Date of Patent: April 5, 2005
    Assignee: Minebea Co., Ltd.
    Inventors: Taiichi Miya, Mutsumi Matsuura
  • Patent number: 6876287
    Abstract: A bobbin, supporting a winding and intended to be disposed in a circular core, which core includes circular top and bottom core collars having first and second bores, respectively, and a cylindrical member maintaining the top and bottom core collars at a predetermined distance from one another, the first and second bores defining a core bore that is concentric with the rotation axis of the core, includes a spool that supports the winding, top and bottom bobbin collars coupled on either side of the spool, and protrusions disposed on the bobbin, the protrusions permitting the bobbin to be press fit into the circular core so as to prevent relative motion between the circular core and the bobbin. If desired, the protrusions can ensure that the centerline of the bore and the centerline of the bobbin are coincident. A rotary transformer and an inductor employing the bobbin are also described.
    Type: Grant
    Filed: May 9, 2003
    Date of Patent: April 5, 2005
    Assignee: Minebea Co., Ltd.
    Inventors: Mutsumi Matsuura, Genta Yoshii
  • Patent number: 6841904
    Abstract: A resolver terminal attachment structure for a resolver (500) including a stator core (1) constructed from multiple laminated plates providing multiple stationary magnetic poles (3) with attendant stationary magnetic pole teeth (4) that protrude in a direction that faces the center of a stator yoke (2), the magnetic poles adapted to accept a stator winding, includes a lead wire fixture (6), which electrically couples the stator winding to a lead wire (204) via attachment pins(7), and two protrusions (2a, 2b) formed integrally and unitarily with the stator core at the outside of the stator core for supporting the lead wire fixture between the protrusions.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: January 11, 2005
    Assignee: Minebea Co., Ltd.
    Inventors: Satoshi Sano, Naofumi Kumagai
  • Patent number: 6815853
    Abstract: A stator core 1 is surrounded by a first insulating member 40 and a second insulating member 41. Locking protrusions 9 are formed on the outer periphery of the stator core 1, and the locking protrusions 9 form a keyway 11. A modular connector 2 includes a key part 21 that fits within the keyway 11 to secure the modular connector 2 to the stator core 1. Fastening pins 18 are embedded in the modular connector 2 to conduct electricity from a mating connector 91 and a lead line 93 to the resolver.
    Type: Grant
    Filed: November 19, 2003
    Date of Patent: November 9, 2004
    Assignee: Minebea Co., Ltd.
    Inventors: Takanobu Koyama, Naofumi Kumagai