Patents Assigned to Yoshizuka Seiki Co., Ltd.
  • Patent number: 5551856
    Abstract: A powder molding press machine is provided with a main body, a plurality of punches provided for the main body and punch operating means for operating the punches. The plurality of punches are assembled into a punch unit so as to allow the punches to move reciprocally, the punch operating units are attached to the main body for individually reciprocating each of the plurality of punches, the operating units having operational end portions corresponding to the plurality of punches. The punch unit is rotated relative to the punch operating units so as to connect the plurality of punches to the corresponding operational end portions.
    Type: Grant
    Filed: November 3, 1993
    Date of Patent: September 3, 1996
    Assignee: Yoshizuka Seiki Co., Ltd.
    Inventor: Takeshi Katagiri
  • Patent number: 5498147
    Abstract: A powder molding press a die plate provided with a die having a die hole, a punch device to be inserted into the die hole and a hydraulic cylinder device attached to the punch device for driving the same, the hydraulic cylinder device being arranged coaxially with the punch device. A movable punch plate may be disposed on one side of the die plate in parallel thereto with a predetermined space and a punch adapter for securing the punch device to the punch plate may be also disposed. The punch device includes a plurality of punches disposed axially in series.
    Type: Grant
    Filed: June 29, 1994
    Date of Patent: March 12, 1996
    Assignee: Yoshizuka Seiki Co., Ltd.
    Inventors: Takeshi Katagiri, Masao Yamamoto, Tukasa Tajima, Siro Shirasaki
  • Patent number: 5401153
    Abstract: The invention provides a press for powder metallurgy in which a die set installed between an upper ram and a lower ram of a main body of the press can be easily fixed or removed and the accuracy of the molded product is improved. An upper part of the lower ram to which a yoke plate of the die set is installed or is provided with a gap adjusting screw displaceable with thread engagement in vertical direction. A hydraulic actuator or other rotary driving device is fixed to a lower part of the lower ram. A driving shaft of the rotary driving device is connected to the gap adjusting screw by a connecting shaft which passes through an axial center of the lower ram. When the die set is installed in the main body of the press, the gap adjusting screw is retracted within the lower ram so as to assure a sufficient gap between the yoke plate and the lower ram.
    Type: Grant
    Filed: November 23, 1993
    Date of Patent: March 28, 1995
    Assignee: Yoshizuka Seiki Co., Ltd.
    Inventors: Takeshi Katagiri, Shiro Shirasaki, Masao Yamamoto
  • Patent number: 5378416
    Abstract: A method of manufacturing a powder molding having a undercut portion, etc. comprises filling a space of a die with a powder, pressing the powder in the space of the die by punches inserted therein through an opening of the die, and withdrawing a undercut portion shaping means from the space of the die for extracting the powder molding.
    Type: Grant
    Filed: July 27, 1993
    Date of Patent: January 3, 1995
    Assignees: Nissan Motor Co., Ltd., Yoshizuka Seiki Co., Ltd.
    Inventors: Yuji Kishi, Takeshi Katagiri
  • Patent number: 5326242
    Abstract: A powder molding press includes a die plate provided with a die having a die hole, a punch device to be inserted into the die hole and a hydraulic cylinder device attached to the punch device for driving the same, the hydraulic cylinder device being arranged coaxially with the punch device. A movable punch plate may be disposed on one side of the die plate in parallel thereto with a predetermined space and a punch adapter for securing the punch device to the punch plate may be also disposed. The punch device includes a plurality of punches disposed axially in series.
    Type: Grant
    Filed: August 9, 1991
    Date of Patent: July 5, 1994
    Assignee: Yoshizuka Seiki Co., Ltd.
    Inventors: Takeshi Katagiri, Masao Yamamoto, Tukasa Tajima, Siro Shirasaki
  • Patent number: 5288440
    Abstract: A power molding press is controlled, in which a stepped mold product having a plurality of stepped portions is molded by compressing powder within a mold by relatively moving an upper punch assembly, a lower punch assembly including a plurality of lower punches arranged concentrically with each other and the mold by detecting a speed ratio of moving speeds of the upper and lower punch assemblies moved by the respective driving sources at a time of compressing the respective stepped portions of the mold product during a compressing time from a pressing start time to a pressing completion time, detecting positions of the upper and lower punch assemblies and the mold, detecting a compression ratio of compressed dimensions of the stepped portions of the mold product, and controlling the respective drive sources to control the relative moving speeds of the upper punch assembly, the lower punch assembly and the mold so that the speed ratios substantially accord with the compression ratios of the respective stepped
    Type: Grant
    Filed: February 4, 1992
    Date of Patent: February 22, 1994
    Assignee: Yoshizuka Seiki Co., Ltd.
    Inventors: Takeshi Katagiri, Masao Yamamoto, Tukasa Tajima, Siro Sirasaki
  • Patent number: 5219319
    Abstract: An apparatus for replacing the tool sets without requiring any fixing or removal of the fluid pressure pipes such as hydraulic hoses or the like when the tool sets are fixed to or removed from the main body of the power molding press. Swing arms 6 having arm lengths set therein are oscillatably and rotatably fitted to the arm shafts 5 vertically installed at proper side locations of the main body 1 of the press in such a way as the rotating radius of the arm shafts may overlap the mounting position of the main body 1 of the press. The extreme ends of the swing arms 6 are provided with supporting boxes 7 on which the tool sets 3 are mounted. Rotation of the swing arms 6 enables the tool sets 3 to be moved toward or away from the centeral part of the main body 1 of the press and then the tool sets 3 to be fixed to or removed from the main body 1 of the press.
    Type: Grant
    Filed: December 13, 1991
    Date of Patent: June 15, 1993
    Assignee: Yoshizuka Seiki Co., Ltd.
    Inventors: Takeshi Katagiri, Masao Yamamoto, Shiro Shirasaki
  • Patent number: 4577981
    Abstract: The spindle device of the present invention is of the type wherein a shaft is carried by ball bearings or tapered roller bearings in a front side and a rear side, and a preload is applied by a spring. A gimbal ring is inserted between an outer ring of the front side bearing and a shoulder face of a housing on which the outer ring is mounted. With this construction, the axial and radial deviations of the shaft can be minimized.
    Type: Grant
    Filed: June 12, 1984
    Date of Patent: March 25, 1986
    Assignee: Yoshizuka Seiki Co., Ltd.
    Inventor: Quanbee Kimura
  • Patent number: 4379684
    Abstract: Press for powder metallurgy and method of simultaneous compression of powder in a die disclosed which includes descent speed differentially control apparatuses for simultaneous compression powder in the die from both the upper and lower direction by an upper punch and a lower punch. The descent speed of an upper ram is transferred to the upper punch at that speed, and the speed is changed to lower speed through the control device than the upper punch speed and the controlled lower speed is transferred to a die holder which is simultaneously descended with the controlled lower speed together with the high speed upper punch.
    Type: Grant
    Filed: June 11, 1981
    Date of Patent: April 12, 1983
    Assignee: Yoshizuka Seiki Co., Ltd.
    Inventors: Takeshi Katagiri, Takakazu Tsuchifuji
  • Patent number: 4140449
    Abstract: Improvement of a press for powder metallurgy having one or more rotatably arms mounting horizontally and respectively on an axis which is set up vertically at suitable portion of front and or rear walls of housing of the press. The arm has a box for supporting a die set and a metal mold on an end. The die set and the metal mold being supported in the box are easily transferred to a receiving portion thereof of an entrance of the press by rotation of the arm to horizontal direction, and the transferred die set and the metal mold are installed in accurate portion of the press by hand or a driven power means.
    Type: Grant
    Filed: September 16, 1977
    Date of Patent: February 20, 1979
    Assignee: Yoshizuka Seiki Co., Ltd.
    Inventors: Katagiri Takeshi, Ozu Masaaki