Patents Assigned to Kabushiki Kaisha Yaskawa Denki Seisakusho
  • Patent number: 4950849
    Abstract: A contact detector for movable objects comprises two opposite circular plates in which a plurality of cylindrical depressed portions are equidistantly opened on the same circumferences from a common center axis of the two circular plates, respectively, a plurality of steel balls, having a diameter larger than the diameter of each depressed portion, inserted into corresponding depressed portions of the two circular plates, and hardened layers formed on the portions in contact with the steel balls of the circular plates by pressurizing two circular plates from the opposite sides of respective depressed portions. A portion of the surface of each steel ball is depressed into each recessed portion, and the one circular plate and the steel balls are pressed into contact with the other circular plate by an elastic member.
    Type: Grant
    Filed: July 19, 1989
    Date of Patent: August 21, 1990
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Kaoru Kimura, Shunji Sato, Masahiko Ookura
  • Patent number: 4948091
    Abstract: A motor-operated valve is constructed such that a stator is provided outside of a nonmagnetic tubular member allowing flow of a fluid, with stator coils wound around a plurality of magnetic poles, and a plurality of permanent magnets are secured to an operating surface of each magnetic pole. The permanent magnets are magnetized into a number of pole-pairs arranged at a constant pitch. A rotor is rotatably supported inside of the tubular member. A number of induction teeth are formed along the circumference of the rotor at a pitch equal to the pitch of the pole-pairs of the permanent magnets, and the total number of the induction teeth is so selected that it is different from the total number of the pole-pairs of the permenant magnets by an amount equal to an even number. A mechanism including a rotation-preventing means is also provided in the rotor for converting the rotating movement of the rotor into a linear movement of a valve member.
    Type: Grant
    Filed: February 16, 1990
    Date of Patent: August 14, 1990
    Assignees: Kabushiki Kaisha Yaskawa Denki Seisakusho, Toyo Engineering Corporation
    Inventors: Ikumi Satoh, Jun Nakano, Riichiroh Harada, Tatsuhiko Koba, Yuichi Fujita, Kazumi Shima
  • Patent number: 4946337
    Abstract: In a precision operable robot arm comprising four levers pivotally connected with each other into a paralle arranged link form, when one ends of first and second levers aligned vertically, for example, are driven respectively by two motors such that the levers are swung around the alignment axis in a horizontal plane, for example, a work supporting device provided at an outwardly extending end of the fourth lever is also moved in a horizontal plane.A first pulley is fixedly secured to a position aligning with the driving shafts of the two motors, while second and third pulleys, which are integrally rotatable, are rotatably supported by a pivot pin coupling the second and fourth levers, and fourth pulley rotatably supported at the outer end of the fourth lever is fixed to the work supporting device.
    Type: Grant
    Filed: July 5, 1988
    Date of Patent: August 7, 1990
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Shuichi Tonai, Shigeo Matsushita
  • Patent number: 4937426
    Abstract: A method is disclosed for correcting the travel path of an oscillating robotic welding torch tracing a groove line defined by an upper and lower plate. According to one aspect of the invention, a first integrated value of the welding current at the center of oscillation is compared with second and third integrated values of the welding current at opposite first and second ends of the oscillation, respectively. The travel path of the robotic welding torches adjusted towards the second end of oscillation when the second and third integrated values of the welding current are smaller than the first integrated value of the welding current. According to another aspect of the present invention, a first integrated value of the welding current at the second end of oscillation of a previous oscillation torch is compared with a second integrated value of the welding current at the second end of oscillation of a subsequent oscillation.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: June 26, 1990
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Seigo Nishikawa, Shinji Okumura, Tadayuki Amano, Kazutoshi Hata
  • Patent number: 4926604
    Abstract: Burring by way of a grind stone using a robot has been rarely practiced because the correction of abrasion of the grind stone involves a problem. There has been hitherto proposed a method for correction of abrasion by making use of a force sensor or a special tool holder apparatus. However, since the apparatus is expensive and low in reliability, it has not been practical. In the present invention, a coordinate system is set to a wearing tool mounted to a wrist of a robot separately from the rectangular coordinates of the robot, and the worn amount of the tool detected by use of a sensor is subjected to parallel shifting on the coordinate system of the tool set to the tool to effect correction of abrasion, which is characterized in that a special hard is not required, and operation is simple.
    Type: Grant
    Filed: December 28, 1988
    Date of Patent: May 22, 1990
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Masaaki Hara, Seigo Nishikawa, Taketoshi Tazaki, Hiroshi Inokuchi
  • Patent number: 4890186
    Abstract: In the past, a power fuse need be replaced after the current limiting operation and cannot be repeatedly used. To solve this problem, there has been proposed a permanent fuse or the like which uses an alkaline metal having a low melting point such as Hg, K, Na, etc.These are harmful to human body, and since they are completely vaporized, an insulated layer of a vessel cannot be removed, thus giving rise to a difficulty toward higher voltage.The present invention makes best use of characteristic of carbon which sublimates. A plurality of boundary layers of carbon lumps are disposed in series or in series and parallel, and electrode potential drops at the time of large current and potential drops of arc column under high atmosphere presssure which produces for a short period of time are utilized to effect current limiting.
    Type: Grant
    Filed: February 14, 1989
    Date of Patent: December 26, 1989
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Chiaki Matsubara, Hirokuni Ishikawa, Masao Ojima
  • Patent number: 4884189
    Abstract: A locus interpolation device characterized in that the device is attached to an end of a wrist of a movable structure such as a robot, with a tool supported by the device, and a circular or noncircular locus is interpolated by controlling the operation of the tool independently from that of the movable structure.
    Type: Grant
    Filed: September 25, 1987
    Date of Patent: November 28, 1989
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Kaoru Kimura, Masanori Nishi, Yoshikatsu Minami
  • Patent number: 4862044
    Abstract: A method for adjusting an encoder directly coupled with a brushless motor, wherein a set of sensor match marks are provided on a sensor base plate mounting a number of sensor elements, while another set of disc match marks are provided on an encoder disc at positions where, during the time when the motor is energized but locked, a phase difference between an EMF voltage waveform of the motor and the output voltage waveform of a specific phase of the encoder is made equal to a predetermined value, rough adjustment of the encoder is executed by aligning the two sets of match marks between each other, a gap between the encoder disc and the sensor is adjusted suitably, and then the sensor base plate is slightly rotated relative to the stator of the brushless motor for executing a fine adjustment of the encoder.
    Type: Grant
    Filed: March 18, 1988
    Date of Patent: August 29, 1989
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Kunihiko Karashima, Shoji Kumada, Katsumasa Yoshida, Hiroharu Katase
  • Patent number: 4851771
    Abstract: A magnetic encoder for detecting the speed of an actuator adapted to carry out rotational movement or linear movement by a magneto-resistor is disclosed. This magnetic encoder is intended to carry out output conversion by using a stripe-shaped magneto-resistor located close to a magnetic medium with respect to a periodic magnetic field coming out of the magnetic medium on which at least one track of magnetization patterns are recorded by a pitch p in order to generate the periodic magnetic field depending on the required position reading accuracy. When the unit stripe length of the magneto-resistor is represented by l and the closest distance between the magnetic medium and the magneto-resistor is represented by g, the angle .alpha.
    Type: Grant
    Filed: February 24, 1988
    Date of Patent: July 25, 1989
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Michiaki Ikeda, Hisayuki Kaku, Shinji Yamashita, Kenji Hara, Hiroyuki Ono
  • Patent number: 4848814
    Abstract: A wafer transferring hand is so constructed that at least three seats made of a soft low-friction material are provided in an integral manner, a groove having a width slightly wider than the thickness of the wafer is formed in the laterally arranged seats, the bottom of the groove being arcuated in a manner conforming to the periphery of the wafer, while a similar groove having an adjustable width is provided in the seat arranged at the center, the bottom of the groove being spaced apart outwardly from the periphery of the wafer, and at least two cut-away portions are provided between the seats so as to provide a gap between the periphery of the wafer and the bottom of the cut-away portion.
    Type: Grant
    Filed: October 27, 1987
    Date of Patent: July 18, 1989
    Assignees: Nihon Shinku Gijutsu Kabushiki Kaisha, Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Takeo Suzuki, Junpei Yuyama
  • Patent number: 4795954
    Abstract: A method and apparatus for controlling a resolver of two-phase excitation and one-phase detection type wherein an erroneous component in the output of the resolver is eliminated by periodically reversing the rotational direction of a rotating magnetic field generated in the resolver.
    Type: Grant
    Filed: December 22, 1986
    Date of Patent: January 3, 1989
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Shigeru Sakurai, Akiho Hasuo, Kazuo Tanabe
  • Patent number: 4794290
    Abstract: An active type magnetic bearing for controllably supporting a rotatable shaft made of a magnetic material is constructed such that a stator made of an annular formed laminated iron core is provided around the rotatable shaft, a number of slots are formed along an internal surface of the iron core, stator windings of a number of phases are wound so as to be settled in the slots, thin sheet-like permanent magnets magnetized radially to provide a number of poles are secured onto the internal surface of the annular formed iron core with a predetermined air gap maintained between the permanent magnets and the rotatable shaft, and the stator windings of each phase are so wound that upon energization, a magnetic field thereby produced enhances a magnetic field produced by one of the permanent magnets while it reduces a magnetic field produced by another permanent magnet provided at a position 180.degree. spaced apart from that one of the permanent magnets.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: December 27, 1988
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Nagahiko Nagasaka
  • Patent number: 4745312
    Abstract: In a stepping motor having a stator and a rotor, the stator is made of a laminated iron core of a cylindrical shape having a plurality of slots formed around the periphery at a constant pitch. Coil windings concentrately wound are inserted in the slots, and permanent magnets of a planar shape are adhere around the surface of the iron core, thereby providing stator magnetic poles. The rotor on the other hand is made in the form of a circular disk at least a part of which is made of a magnetic material. A number of teeth are formed around the peripheral portion at a constant pitch thereby providing rotor magnetic poles which are positioned in opposition to the stator magnetic poles with a predetermined air gap maintained therebetween.
    Type: Grant
    Filed: December 16, 1986
    Date of Patent: May 17, 1988
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Nagahiko Nagasaka
  • Patent number: 4706007
    Abstract: A surface pulse motor having a stator and a mover is provided such that the stator is made of a magnetic material of a planar configuration with a number of projections formed on a surface thereof at positions corresponding to the intersecting points of a first lattice. The mover is made of electromagnets of predetermined phases, each electromagnet having a number of projections formed on a surface thereof opposing the surface of the stator at a pitch equal to that of the first lattice. When a second lattice which is rotated relative to the first lattice by a predetermined angle is assumed, the electromagnets other than the first phase are displaced from that of the first phase by a distance corresponding to a fraction of the pitch of the first lattice in directions of the coordinate axes of the second lattice, respectively.
    Type: Grant
    Filed: May 27, 1986
    Date of Patent: November 10, 1987
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Nagahiko Nagasaka
  • Patent number: 4705971
    Abstract: A linear resolver wherein a stator is made of a magnetic material and is toothed at equal pitches along the direction of measurement, and a movable element is an electromagnet made of an E type or C type core around which a primary single phase winding W.sub..theta. is wound, the surface of the movable element facing the stator and constituting part of a magnetic path of the linear resolver being provided with detection secondary windings bonded to the surface, and the detection secondary windings each having as its winding pitch a half the pitch between the teeth of the stator; wherein the movable element is supported relative to the stator with a constant gap therebetween and guided in sliding relation to the stator only in the longitudinal direction of the stator.
    Type: Grant
    Filed: November 8, 1985
    Date of Patent: November 10, 1987
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Nagahiko Nagasaka
  • Patent number: 4703297
    Abstract: In the permanent magnet type actuator, an armature made of a hollow cylindrical permanent magnet is held to be movable in its axial direction. A stator made of an electromagnet comprises a magnet core having two portions one placed outside of the permanent magnet and the other placed inside of the same, thereby applying a unipolar magnetic field to the armature. A plurality of inductor teeth are formed on the surfaces of the core portions opposing to each other, and means are further provided for energizing a coil of the electromagnet by an exciting current and driving the armature in its axial direction.
    Type: Grant
    Filed: December 16, 1986
    Date of Patent: October 27, 1987
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Nagahiko Nagasaka
  • Patent number: 4605853
    Abstract: A supporting mechanism for a fixed detection section in a detection device comprises the fixed detection section and a rotary detection section. The mechanism comprises a plate spring and a supporting plate. The plate spring is mounted on a fixed housing of a drive motor in spaced relation thereto, and has at least in part an elastic portion whose resilient force direction along an axial direction of the rotary shaft. The supporting plate of a ring shape has a plurality of elongated apertures formed therein along a concentric line, and is mounted on the plate spring in spaced relation thereto. The fixed detection section is fixedly connected with screws through the elongated apertures to the supporting plate.
    Type: Grant
    Filed: September 27, 1984
    Date of Patent: August 12, 1986
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Shoji Kumada, Hideyuki Asai
  • Patent number: 4594918
    Abstract: In a wrist mechanism of the type that two sets of differential speed reduction devices are provided within a wrist and arranged symmetrically of and perpendicularly to the axis of an arm and that the adjustment of the angle of the wrist and the rotation of a tool are carried out through the differential speed reduction devices, a novel wrist mechanism is provided for preventing a wrist cover from entering into a dead point condition. The wrist mechanism comprises a guide protrusion and a guide. The guide protrusion is provided on the side of a bracket related by one of wrist covers on a wrist portion side, the side being located outside a speed reduction shaft and on the side of the wrist portion relative to the axis of an input shaft. The guide is provided on the inner face of the wrist cover at a point on a locus of the guide protrusion relative to the wrist cover, the point being defined by that at least the axes of a tool rotation shaft and input shafts coincide with each other.
    Type: Grant
    Filed: July 20, 1984
    Date of Patent: June 17, 1986
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Karou Kimura, Junichiro Ogawa
  • Patent number: 4590398
    Abstract: A brush holder comprising a brush box and a brush terminal. The brush box includes a brush sliding tube which is mounted at opposite upper sides thereof with a pair of side plates. Each of the side plates forms a clearance and has an upper opening and a lower opening. The brush terminal has a pair of bent pieces and a central portion therebetween for connecting a pigtail. An engaging projection is formed on the bent pieces. The engagement and fixation between the brush box and the brush terminal are performed outside of the brush box, with the engaging projection coupling to the lower opening, and the bent pieces inserted into the clearance.
    Type: Grant
    Filed: October 3, 1984
    Date of Patent: May 20, 1986
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Toshio Nagamatsu
  • Patent number: 4528632
    Abstract: In a control device for an industrial articulated robot, in the linear interpolation between two specified points, the distance between the two points is divided into segments, and the interpolation increments of the articulation drive axes for each interpolation internal, which correspond to the segments, are calculated for interpolation so that the interpolation increments are distributed uniformly with time.
    Type: Grant
    Filed: March 8, 1982
    Date of Patent: July 9, 1985
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Satoru Nio, Shinobu Sato, Shigemi Nobayashi, Toyoji Hamashima