Patents Assigned to Hitachi Koki Company, Limited
  • Patent number: 4704963
    Abstract: A device for cleaning a rotary type-carrier, in which a brush which contacts the type-carrier continuously to clean it during normal operation may be moved so that its rotary center is positioned more closely to the type-carrier. As a result, as the brush wears out, it may maintain contact with the type-carrier, obviating the need for frequent replacement.
    Type: Grant
    Filed: November 1, 1985
    Date of Patent: November 10, 1987
    Assignee: Hitachi Koki Company, Limited
    Inventors: Hiroshi Nishimura, Masao Miyasaka
  • Patent number: 4628459
    Abstract: A circuit arrangement including a computer is built in an electrical jig saw where various data or information, such as the sort of the material of the workpiece, the thickness of the workpiece, desired degree of finish and way of cutting, are manually inputted via a keyboard so that the computer selects and determines optimum working condition, such as the sort of blade to be used, the locus of the blade, blade strokes per minute which is in proportion to the motor speed, and the necessity of application of coolant oil. The circuit arrangement also comprises circuitry for automatically controlling the rotational speed of the motor of the jig saw so that an actual speed of the blade equals a desired speed represented by strokes per minute. A display unit is coupled with the computer for indicating input and output data of the computer for supplying visual information to the user of the jig saw.
    Type: Grant
    Filed: March 7, 1984
    Date of Patent: December 9, 1986
    Assignee: Hitachi Koki Company, Limited
    Inventors: Shigeru Shinohara, Shun Suzuki, Tatsuo Innami
  • Patent number: 4621343
    Abstract: In a printer of the type arranged to fire print hammers in accordance with the result of comparison between character codes and print data such that a plurality of subscans are effected during an interval in which a type carrier moves by a distance corresponding to character pitch, a flag bit storing region is provided to a character code memory and/or a print data memory. Data indicative of numerical order of subscans from a print control circuit is added to several lower bits of data used to designate the address of the character code memory, and the resultant sum is compared with the flag bits read out from the flag bit storing region to see whether the addresses of the character code memory are correctly accessed. Another flag bit storing region is provided to a print data memory, and these flag bits are read out and compared with the data indicative of the numerical order of subscans to see if the addresses of the print data memory are correctly accessed.
    Type: Grant
    Filed: August 26, 1983
    Date of Patent: November 4, 1986
    Assignee: Hitachi Koki Company, Limited
    Inventors: Toshiaki Fujieda, Kazuyuki Kubo
  • Patent number: 4616943
    Abstract: An auxiliary ribbon separator for use on a dot-line printer is positioned to prevent vertical ribbon displacement in the presence of upward forces such as caused by perforations on continuous feed paper. The auxiliary separator is located so that the ribbon is guided past an end of a front yoke. The front yoke serves as a course ribbon guide and is a component of the electro-magnetic assembly of the print head associated with the printer. The auxiliary separator may be shaped so as to facilitate loading of the ribbon in the printer.
    Type: Grant
    Filed: March 9, 1984
    Date of Patent: October 14, 1986
    Assignee: Hitachi Koki Company, Limited
    Inventors: Yoshikane Matsumoto, Toshio Hiki
  • Patent number: 4609815
    Abstract: An apparatus for detecting a feeding of paper has a reflector which is mounted on a bottom of a switch lever. The switch lever, in turn, is slidably mounted on black paper retainer plate which has poor reflecting properties, and a light emitting element emits light which is reflected by the paper towards a light receiving element. When paper which has good reflecting properties is being fed, the reflector is slid so that it is no longer located opposite the light emitting element, and any light passing through holes in the paper is thus poorly reflected by the black paper retainer plate, thereby enabling the light receiving element to readily detect the presence or absence of a hole in the paper. However, when the paper being fed has poor reflecting properties, the reflector is slid so that it is located opposite the light emitting element, and any light passing through one of the holes in the paper is strongly reflected by the reflector.
    Type: Grant
    Filed: March 3, 1983
    Date of Patent: September 2, 1986
    Assignee: Hitachi Koki Company, Limited
    Inventors: Hiroshi Hishinuma, Masao Miyasaka, Kenji Okada, Shuichi Morio
  • Patent number: 4609861
    Abstract: A quick battery charger according to the present invention comprises a circuit for detecting the voltage of the battery (3), a constant-current charging circuit, a constant-voltage charging circuit, and a timer circuit responsive to the voltage detecting circuit. At the beginning in charging operation, the battery is charged at a constant current, and when the voltage of the battery exceeds a predetermined value, charging mode is changed to constant-voltage charging which last for a predetermined period of time determined by the timer circuit. The charger may also comprise a trickle charge circuit so that trickle charge takes place after the constant-voltage charge. One or more heat-sensitive elements (5, 6, 69) may be used for providing temperature compensation or fail-safe in response to the heat from the battery and heat from parts of the battery charger. As a timer may be used a capacitor (50) which may be forcibly charged to insure a given period of time of the constant-voltage charging.
    Type: Grant
    Filed: November 19, 1984
    Date of Patent: September 2, 1986
    Assignee: Hitachi Koki Company, Limited
    Inventors: Masahiro Inaniwa, Shun Suzuki, Yoichi Ogawa
  • Patent number: 4556831
    Abstract: In an electrical tool having a clutch for adjusting rotational torque of the driven shaft, a limit switch of double-throw type is used for detecting the state of the clutch, and a capacitor is arranged to be charged via the limit switch. In one embodiment of the instant invention, the capacitor is normally discharged and is charged when the clutch assumes a disengaged state, thereby producing a trigger pulse used for making a short circuit for the motor only when the capacitor is not fully charged. In another embodiment, the capacitor is normally charged, and is discharged when the clutch assumes a disengaged state, thereby producing a trigger pulse used for making a short circuit for the motor. With this arrangement a switching circuit provided for making the short circuit for the motor is effectively prevented from making the short circuit when a power switch is turned on irrespective of the state of the clutch.
    Type: Grant
    Filed: July 11, 1984
    Date of Patent: December 3, 1985
    Assignee: Hitachi Koki Company, Limited
    Inventors: Junshin Sakamoto, Shigeru Shinohara
  • Patent number: 4528492
    Abstract: A battery charger comprises a rectifier connected to a source of alternating voltage for generating a rectified sinusoidal halfwave voltage and a thyristor connected in a first circuit between the rectifier and a rechargeable battery for applying the sinusoidal halfwave voltage thereto. An RC triggering network is provided in a second circuit between the battery and the gate of the thyristor for triggering the same into conduction to apply the sinusoidal voltage to the battery when the instantaneous value of the voltage is higher than the voltage of the battery. A temperature responsive switch is provided for disconnecting the second circuit when the battery is heated to a temperature higher than a predetermined value. Further provided is a transistor responsive to the temperature responsive switch for establishing a short-circuit path to the gate of the thyristor.
    Type: Grant
    Filed: April 5, 1983
    Date of Patent: July 9, 1985
    Assignee: Hitachi Koki Company, Limited
    Inventors: Masahiro Inaniwa, Yoichi Ogawa
  • Patent number: 4520965
    Abstract: An electric wire is wound as coil turns in slots in electric rotating machinery component such as a stator or an armature. The wire as it is supplied from a nozzle or flyer is guided by movable formers into successive layers of coil turns in the slots without forming an unwanted dead space in the slots. The formers are moved in radial increments to provide successive spaces in the slots for allowing the successive coil turn layers to be neatly laid in the spaces.
    Type: Grant
    Filed: August 4, 1983
    Date of Patent: June 4, 1985
    Assignee: Hitachi Koki Company, Limited
    Inventors: Kazuo Kimura, Yukinori Taneda, Shinichi Tsuyuki, Shun Suzuki, Yoshio Hashimoto, Shinichi Sakamoto
  • Patent number: 4481880
    Abstract: A dot printer in which vibration is eliminated without the use of a separate counterweight. The printer includes first and second hammer banks each holding a plurality of dot printing elements. The first and second hammer banks are spaced apart from each other a predetermined distance in the direction in which a printing sheet passes. A motor and oppositely-phased drive cams reciprocate the two hammer banks in opposite directions parallel to a dot printing direction.
    Type: Grant
    Filed: April 19, 1983
    Date of Patent: November 13, 1984
    Assignee: Hitachi Koki Company Limited
    Inventors: Makoto Kurosawa, Hiroshige Nakano, Kensei Hosoya, Tsuneki Kobayashi
  • Patent number: 4479430
    Abstract: Systems for discriminating among a plurality of type carriers differing in number of characters and pitch of characters are disclosed. In one circuit, the type carrier is provided with synchronizing marks and discrimination marks in addition to the usual type character marks. The synchronizing mark is located at the beginning of a set of characters, and the discrimination mark is located a predetermined distance from the synchronizing mark according to the number of characters and pitch of the particular type carrier. This distance is determined by counting type character marks. In another circuit, one or more discrimination marks are provided between type character marks at the beginning of a set of characters. The number of discrimination marks indicates the number of characters of the particular type carrier. In either circuit, a counter of only a few stages and a simple decoding circuit are all that are required to carry out the discrimination operation.
    Type: Grant
    Filed: March 20, 1984
    Date of Patent: October 30, 1984
    Assignee: Hitachi Koki Company Limited
    Inventors: Hiroshige Nakano, Tsuneki Kobayashi, Shigenobu Katagiri
  • Patent number: 4472985
    Abstract: A power-driven bolt fastening tool or shearing wrench includes an outer socket adapted to fit over the head of a bolt to be fastened and an inner socket disposed coaxially in the outer socket and adapted to fit over the tip of the bolt. A planetary gear mechanism comprises an internal gear coupled to the outer socket through a lost-motion connection, planet gears supported on shafts coupled to the inner socket, and a sun gear in mesh with the planet gears. The lost-motion connection comprises a torsion spring acting between the internal gear and the outer socket for allowing the internal gear to angularly move for a limited angular interval before the outer and inner sockets fit fully over the bolt head and tip and before a fastening torque is transmitted from the sun gear to the outer socket.
    Type: Grant
    Filed: October 30, 1981
    Date of Patent: September 25, 1984
    Assignee: Hitachi Koki Company, Limited
    Inventor: Hiroaki Orikasa
  • Patent number: 4473006
    Abstract: Systems for discriminating among a plurality of type carriers differing in number of characters and pitch of characters are disclosed. In one circuit, the type carrier is provided with synchronizing marks and discrimination marks in addition to the usual type character marks. The synchronizing mark is located at the beginning of a set of characters, and the discrimination mark is located a predetermined distance from the synchronizing mark according to the number of characters and pitch of the particular type carrier. This distance is determined by counting type character marks. In another circuit, one or more discrimination marks are provided between type character marks at the beginning of a set of characters. The number of discrimination marks indicates the number of characters of the particular type carrier. In either circuit, a counter of only a few stages and a simple decoding circuit are all that are required to carry out the discrimination operation.
    Type: Grant
    Filed: November 27, 1978
    Date of Patent: September 25, 1984
    Assignee: Hitachi Koki Company Limited
    Inventors: Hiroshige Nakano, Tsuneki Kobayashi, Shigenobu Katagiri
  • Patent number: 4469453
    Abstract: A driving motor of the type employing pneumatic bearings is improved by reducing a weight moment of an upper pad by cutting away a portion thereof, to make the gaps of the bearing pads of the motor more nearly uniform.
    Type: Grant
    Filed: April 22, 1983
    Date of Patent: September 4, 1984
    Assignee: Hitachi Koki Company, Limited
    Inventors: Hiroomi Kozawa, Shinichi Nishino, Shigenobu Katagiri
  • Patent number: 4450323
    Abstract: A reversible switch comprises four fixed contact members mounted within a base, each having an arcuate contact jointly defining an interrupted circular wall. A cylindrical body rotatable within the wall includes a pair of contact members slidably engageable with the fixed contacts to reverse polarity of an electrical circuit when rotated 90.degree. between first and second positions. An eccentric pin projecting from the body through an arcuate slot formed in a cover mounted on the base rotates the body via engagement with a lever pivotably mounted on the cover. The rotatable body is selectively retained in first or second position by a spring-biased cap received in a pair of positioning holes in the cover.
    Type: Grant
    Filed: November 24, 1981
    Date of Patent: May 22, 1984
    Assignee: Hitachi Koki Company, Limited
    Inventor: Takeshi Iitsuka
  • Patent number: 4442878
    Abstract: A hand-held power tool, such as an electric planer or the like, comprises a mechanism for moving or forwarding the body of the tool in a straight hand path. The mechanism includes a rotary wheel or a plate attached to the tool body so that the rotary wheel or plate contacts the surface of a work piece when the tool body is placed thereon. The rotary wheel or the plate is made of a material having a high friction coefficient. A plurality of parallel grooves are formed on the surface of the rotary wheel or so that a high degree of friction occurs between the surface thereof and the surface of the work piece should the body move in a direction other than a given direction on the surface of the work piece. The rotary wheel or plate is biased toward the work piece with the biasing force applied to the rotary wheel being variable.
    Type: Grant
    Filed: August 4, 1981
    Date of Patent: April 17, 1984
    Assignee: Hitachi Koki Company, Limited
    Inventors: Seki Moriguchi, Katsuo Koizumi, Sueji Nagayama
  • Patent number: 4432849
    Abstract: A solution of macromolecules or other particles suspended therein is subjected to a centrifugal force applied in one direction and simultaneously to a force imposed in a direction opposite to said one direction by an electric field applied, thereby separating the particles into a position in which the centrifugal force counterbalances the force imposed by the electric field.
    Type: Grant
    Filed: July 6, 1983
    Date of Patent: February 21, 1984
    Assignee: Hitachi Koki Company, Limited
    Inventor: Takayasu Saito
  • Patent number: 4423346
    Abstract: A safety device for preventing overspeed of a rotary shaft driven by an electrical motor is arranged to cut a portion of an electrical circuit feeding the motor with electrical power, by making a cutter received in a rotary member jump up or protrude by a centrifugal force acting on the cutter, so that dangerous overspeed is prevented. The cutter is movably received in a radial bore made in the rotary member, and receives a tensile force from a coil spring which is fixedly supported by the rotary member at one end of the spring. An adjusting screw, which is a cylindrical member, is provided for biasing the cutter against the tensile force from the spring. A critical rotational speed, above which the cutter jumps to break the electrical circuit, can be freely adjusted by changing the position of the adjusting screw. The change in position of the adjusting screw results in both the change of an eccentric distance of the cutter and the change of the tensile force of the spring.
    Type: Grant
    Filed: May 13, 1981
    Date of Patent: December 27, 1983
    Assignee: Hitachi Koki Company, Limited
    Inventor: Yuki Nakazawa
  • Patent number: 4421430
    Abstract: A printing mechanism is provided with a counter-balanced hammer bank such that the hammer bank and a counterweight are oppositely reciprocated by a pair of coaxial, identical, orthogonally oriented cams. Vibration of the printer even at high speed can be eliminated by completely dynamically balancing the system.
    Type: Grant
    Filed: April 12, 1982
    Date of Patent: December 20, 1983
    Assignee: Hitachi Koki Company, Limited
    Inventors: Yoshikane Matsumoto, Tsuneki Kobayashi, Makoto Kurosawa, Minoru Seino
  • Patent number: 4405922
    Abstract: In an impact printer or the like having a plurality of print-hammer drive electromagnets which are respectively connected in series with switching transistors between the terminals of a voltage source, the switching transistors are normally gated into conduction by gating signals with a duration sufficient to energize the electromagnets for operating the associated print hammers. In a test mode which occurs prior to the operation of the printer, the gating signals are successively applied to the switching transistors and the duration of each gating signal is reduced so that the gated transistor remains conductive for a short interval which is insufficient to operate the hammer.
    Type: Grant
    Filed: May 20, 1980
    Date of Patent: September 20, 1983
    Assignee: Hitachi Koki Company, Limited
    Inventors: Shinichi Nishino, Shigenobu Katagiri, Kazuyuki Kubo