Patents by Inventor Keitaro Yonezawa

Keitaro Yonezawa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 11141837
    Abstract: A clamp rod (2) is inserted into a housing so as to be movable in a vertical direction. An attachment hole (6) is provided at a left end portion (3a) of a clamp arm (3), which is attachable to and detachable from the clamp rod (2). The attachment hole (6) passes through the left end portion in the vertical direction. An accommodation hole (8) is provided at a position to the upper right of the attachment hole (6). A transmission member (10) and a wedge member (15) configured to be brought into wedge engagement with the transmission member (10) from above are inserted into the accommodation hole (8). At the time of attaching the clamp arm (3) to the clamp rod (2), the wedge member (15) is pressed downward using a tightening bolt (21), and thereby the wedge member (15) presses the attachment hole (6) via the transmission member (10) and the clamp rod (2), and presses the accommodation hole (8).
    Type: Grant
    Filed: May 30, 2016
    Date of Patent: October 12, 2021
    Assignee: KOSMEK LTD.
    Inventors: Masahiro Yoshimi, Keitaro Yonezawa, Kenta Otani
  • Patent number: 11110560
    Abstract: A piston (4) is inserted in a housing (1) so that the piston (4) is vertically movable. A housing hole (5) is vertically provided in the piston (4), and an output rod (6) is inserted in the housing hole (5) so that the output rod (6) is vertically movable. A converting mechanism (22) converts vertical movement of the piston (4) into rotary movement of the output rod (6). A guide groove (28) is provided in a circumferential direction on an inner circumferential wall of the housing hole (5), and a stopping part (29) is provided at an end part, in the circumferential direction, of the guide groove (28). An engaging member (31) which is provided on an outer circumferential wall of the output rod (6) is caused to face the stopping part (29) of the guide groove (28) at a given distance in the circumferential direction from the stopping part (29) so that the engaging member (31) can be in contact with the stopping part (29).
    Type: Grant
    Filed: March 14, 2018
    Date of Patent: September 7, 2021
    Assignee: KOSMEK LTD.
    Inventor: Keitaro Yonezawa
  • Publication number: 20210164499
    Abstract: A plurality of detection valves (12 and 13) are provided to a housing (1), and at least one air passage (14 and 15), which communicatively connects the detection valves (12 and 13) to each other in series, are provided to the housing (1). One or some of the detection valves (12 and 13) are each configured as a throttle detection valve (13) including a throttle passage (56a).
    Type: Application
    Filed: July 30, 2019
    Publication date: June 3, 2021
    Inventors: Hideaki YOKOTA, Keitaro YONEZAWA
  • Publication number: 20210053167
    Abstract: A clamping device (2) includes: a turning-supporting member (26) formed so as to support a housing (3) which turns when a clamping position is set, the housing (3) turning toward a desired turning angle position about an axis of the housing (3) while maintaining the axis at a constant position; and a bolt (46) which fixes the housing (3) to the turning-supporting member (26) at the desired turning angle position.
    Type: Application
    Filed: January 22, 2019
    Publication date: February 25, 2021
    Inventors: MASAHIRO YOSHIMI, KEITARO YONEZAWA
  • Publication number: 20200230757
    Abstract: A piston (4) is inserted in a housing (1) so that the piston (4) is vertically movable. A housing hole (5) is vertically provided in the piston (4), and an output rod (6) is inserted in the housing hole (5) so that the output rod (6) is vertically movable. A converting mechanism (22) converts vertical movement of the piston (4) into rotary movement of the output rod (6). A guide groove (28) is provided in a circumferential direction on an inner circumferential wall of the housing hole (5), and a stopping part (29) is provided at an end part, in the circumferential direction, of the guide groove (28). An engaging member (31) which is provided on an outer circumferential wall of the output rod (6) is caused to face the stopping part (29) of the guide groove (28) at a given distance in the circumferential direction from the stopping part (29) so that the engaging member (31) can be in contact with the stopping part (29).
    Type: Application
    Filed: March 14, 2018
    Publication date: July 23, 2020
    Applicant: KOSMEK LTD.
    Inventor: KEITARO YONEZAWA
  • Patent number: 10024340
    Abstract: A first piston (4) which is coupled to an output rod (2) and which is inserted in a housing (3) is driven upward by a pressurized fluid. A second piston (6) which is arranged above the first piston (4) is driven downward. This causes a wedge-type force multiplier (M), arranged above the first piston (4), to carry out force multiplication driving with respect to the output rod (2).
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: July 17, 2018
    Assignee: KOSMEK LTD.
    Inventors: Hideaki Yokota, Keitaro Yonezawa
  • Patent number: 10018191
    Abstract: Apparatus configuration in which: a piston (10) is inserted into a housing (1) ascendably and descendably; and pressurized oil supplied to and discharged from a driving chamber (11) arranged above the piston (10). An output rod (15) inserted into an upper wall (2) of the housing (1) protrudes upward from the piston (10). A descent-detecting first detection valve (31) and an ascent-detecting second detection valve (32) arranged outside the periphery of the output rod (15) and in the upper wall (2), circumferentially spaced apart at a predetermined interval. Each first detection valve (31) and second detection valve (32) has an operated portion (49) (79) which faces the piston (10) from above. The apparatus is configured so that pressurized air for detection is supplied through a first supply passage (B1) and a second supply passage (B2) inlets (31a) (32a) of the first detection valve (31) and the second detection valve (32), respectively.
    Type: Grant
    Filed: December 25, 2013
    Date of Patent: July 10, 2018
    Assignee: KOSMEK LTD.
    Inventors: Hideaki Yokota, Keitaro Yonezawa
  • Publication number: 20180071894
    Abstract: A clamp rod (2) is inserted into a housing so as to be movable in a vertical direction. An attachment hole (6) is provided at a left end portion (3a) of a clamp arm (3), which is attachable to and detachable from the clamp rod (2). The attachment hole (6) passes through the left end portion in the vertical direction. An accommodation hole (8) is provided at a position to the upper right of the attachment hole (6). A transmission member (10) and a wedge member (15) configured to be brought into wedge engagement with the transmission member (10) from above are inserted into the accommodation hole (8). At the time of attaching the clamp arm (3) to the clamp rod (2), the wedge member (15) is pressed downward using a tightening bolt (21), and thereby the wedge member (15) presses the attachment hole (6) via the transmission member (10) and the clamp rod (2), and presses the accommodation hole (8).
    Type: Application
    Filed: May 30, 2016
    Publication date: March 15, 2018
    Applicant: KOSMEK LTD.
    Inventors: Masahiro YOSHIMI, Keitaro YONEZAWA, Kenta OTANI
  • Patent number: 9909600
    Abstract: A driving chamber (11) where pressurized fluid is supplied and discharged is arranged above a piston (10) inserted into a housing (1) ascendably and descendably. An ascent-detecting detection valve (32) is oriented laterally in an upper portion of the housing (1). An operating portion (10b) is provided on an upper portion of the piston (10), and an operated portion (79) movable in response to movement of the operating portion (10b) is provided on the detection valve (32). A transmission ball (70) is inserted into a transmission chamber (67) communicatively connected to an upper portion of the driving chamber (11). The transmission ball (70) converts ascent movement of the operating portion (10b) to lateral movement of the operated portion (79). Pressurized air for detection is supplied to an inlet (32a) of the detection valve (32) through a supply passage (B2).
    Type: Grant
    Filed: January 16, 2014
    Date of Patent: March 6, 2018
    Assignee: KOSMEK LTD.
    Inventors: Hideaki Yokota, Keitaro Yonezawa
  • Patent number: 9833866
    Abstract: An output part is provided to the left end of a clamp arm that is supported by a housing so as to be slidable in the vertical direction. At the left end of the housing, a first hole for spring fitting opens obliquely upward towards the output part. A through hole that links the upper surface and the lower surface of the clamp arm is disposed obliquely upward at a left-leaning part of the clamp arm. A second hole for spring fitting and a female screw hole are formed, in that order, upwards in the through hole. A return spring that is installed through the first hole and the second hole impels the output part upwards. A push bolt that is screwed into the female screw hole rom above compresses the return spring.
    Type: Grant
    Filed: August 2, 2013
    Date of Patent: December 5, 2017
    Assignee: KOSMEK LTD.
    Inventor: Keitaro Yonezawa
  • Patent number: 9573232
    Abstract: A first piston for high load is inserted into a housing so as to be movable vertically, and a second piston for low load is inserted into a cylindrical hole of the first piston so as to be movable vertically. An output portion projects from the second piston to above the housing. A first spring for high load and a second spring for low load are mounted in a spring chamber defined by both pistons and. Both springs and are mounted so as to urge the first piston and the second piston upward. A switching mechanism disposed in the pressure fluid chamber at a side opposite to the spring chamber, connects the first piston selectively to the housing or the second piston.
    Type: Grant
    Filed: March 26, 2012
    Date of Patent: February 21, 2017
    Assignee: KOSMEK LTD.
    Inventors: Hideaki Yokota, Keitaro Yonezawa
  • Patent number: 9458865
    Abstract: A first piston (10) is inserted in a housing (2) so as to be hermetically movable vertically. A second piston (20) is inserted in a cylindrical hole (14) of the first piston (10) so as to be hermetically movable axially, and has an output rod (26) projecting upward from the housing (2). A lock chamber (40) is formed below the first piston (10) and the second piston (20), and a release chamber (42) is formed above the first piston (10) and the second piston (20). A force multiplier (52) is arranged in the housing (2) so as to cause (i) a first force, with which a pressurized fluid supplied into the lock chamber (40) pushes the first piston (10) upward, to be transformed in a force-multiplying manner into a second force and (ii) the second force to be transmitted to the second piston (20). Further, a change-over mechanism (54) is arranged in the housing (2) so as to selectively couple the first piston (10) to the housing (2) or the second piston (20).
    Type: Grant
    Filed: May 16, 2012
    Date of Patent: October 4, 2016
    Assignee: KOSMEK LTD.
    Inventors: Hideaki Yokota, Keitaro Yonezawa
  • Publication number: 20150345521
    Abstract: A driving chamber (11) where pressurized fluid is supplied and discharged is arranged above a piston (10) inserted into a housing (1) ascendably and descendably. An ascent-detecting detection valve (32) is oriented laterally in an upper portion of the housing (1). An operating portion (10b) is provided on an upper portion of the piston (10), and an operated portion (79) movable in response to movement of the operating portion (10b) is provided on the detection valve (32). A transmission ball (70) is inserted into a transmission chamber (67) communicatively connected to an upper portion of the driving chamber (11). The transmission ball (70) converts ascent movement of the operating portion (10b) to lateral movement of the operated portion (79). Pressurized air for detection is supplied to an inlet (32a) of the detection valve (32) through a supply passage (B2).
    Type: Application
    Filed: January 16, 2014
    Publication date: December 3, 2015
    Inventors: Hideaki YOKOTA, Keitaro YONEZAWA
  • Publication number: 20150308423
    Abstract: Apparatus configuration in which: a piston (10) is inserted into a housing (1) ascendably and descendably; and pressurized oil supplied to and discharged from a driving chamber (11) arranged above the piston (10). An output rod (15) inserted into an upper wall (2) of the housing (1) protrudes upward from the piston (10). A descent-detecting first detection valve (31) and an ascent-detecting second detection valve (32) arranged outside the periphery of the output rod (15) and in the upper wall (2), circumferentially spaced apart at a predetermined interval. Each first detection valve (31) and second detection valve (32) has an operated portion (49) (79) which faces the piston (10) from above. The apparatus is configured so that pressurized air for detection is supplied through a first supply passage (B1) and a second supply passage (B2) inlets (31a) (32a) of the first detection valve (31) and the second detection valve (32), respectively.
    Type: Application
    Filed: December 25, 2013
    Publication date: October 29, 2015
    Inventors: Hideaki YOKOTA, Keitaro YONEZAWA
  • Publication number: 20150247512
    Abstract: A first piston (4) which is coupled to an output rod (2) and which is inserted in a housing (3) is driven upward by a pressurized fluid. A second piston (6) which is arranged above the first piston (4) is driven downward. This causes a wedge-type force multiplier (M), arranged above the first piston (4), to carry out force multiplication driving with respect to the output rod (2).
    Type: Application
    Filed: September 26, 2013
    Publication date: September 3, 2015
    Inventors: Hideaki Yokota, Keitaro Yonezawa
  • Publication number: 20150202726
    Abstract: An output part is provided to the left end of a clamp arm that is supported by a housing so as to be slidable in the vertical direction. At the left end of the housing, a first hole for spring fitting opens obliquely upward towards the output part. A through hole that links the upper surface and the lower surface of the clamp arm is disposed obliquely upward at a left-leaning part of the clamp arm. A second hole for spring fitting and a female screw hole are formed, in that order, upwards in the through hole. A return spring that is installed through the first hole and the second hole impels the output part upwards. A push bolt that is screwed into the female screw hole rom above compresses the return spring.
    Type: Application
    Filed: August 2, 2013
    Publication date: July 23, 2015
    Inventor: Keitaro Yonezawa
  • Publication number: 20140191456
    Abstract: A first piston for high load is inserted into a housing so as to be movable vertically, and a second piston for low load is inserted into a cylindrical hole of the first piston so as to be movable vertically. An output portion projects from the second piston to above the housing. A first spring for high load and a second spring for low load are mounted in a spring chamber defined by both pistons and. Both springs and are mounted so as to urge the first piston and the second piston upward. A switching mechanism disposed in the pressure fluid chamber at a side opposite to the spring chamber, connects the first piston selectively to the housing or the second piston.
    Type: Application
    Filed: March 26, 2012
    Publication date: July 10, 2014
    Applicant: KOSMEK LTD.
    Inventors: Hideaki Yokota, Keitaro Yonezawa
  • Publication number: 20140109759
    Abstract: A first piston (10) is inserted in a housing (2) so as to be hermetically movable vertically. A second piston (20) is inserted in a cylindrical hole (14) of the first piston (10) so as to be hermetically movable axially, and has an output rod (26) projecting upward from the housing (2). A lock chamber (40) is formed below the first piston (10) and the second piston (20), and a release chamber (42) is formed above the first piston (10) and the second piston (20). A force multiplier (52) is arranged in the housing (2) so as to cause (i) a first force, with which a pressurized fluid supplied into the lock chamber (40) pushes the first piston (10) upward, to be transformed in a force-multiplying manner into a second force and (ii) the second force to be transmitted to the second piston (20). Further, a change-over mechanism (54) is arranged in the housing (2) so as to selectively couple the first piston (10) to the housing (2) or the second piston (20).
    Type: Application
    Filed: May 16, 2012
    Publication date: April 24, 2014
    Applicant: KOSMEK, LTD.
    Inventors: Hideaki Yokota, Keitaro Yonezawa
  • Patent number: 8366090
    Abstract: A plug portion (27) is projected from a first block (1) so as to be inserted into a insertion hole (5) opened in a second block (2). A support surface (9a) is formed on the first block (1) so as to be brought into contact with a supported surface (2a) formed on the second block (2). In the support surface (9a) is opened a fluid flow hole (59). A gap supporting member (K) acting force upon the second block (2) in such a direction as to separate the second block (2) from the first block (1) so as to form a gap (G1) between the supported surface (2a) and the support surface (9a) is provided on the first block (1). A pull member (21) eliminates the gap (G1) by making the second block (2) approach the first block (1) against the force of the gap supporting member (K) in such a condition that an outer peripheral surface of the plug portion (27) is in close contact with an inner peripheral surface of the insertion hole (5) to bring the supported surface (2a) into contact with the support surface (9a).
    Type: Grant
    Filed: September 7, 2004
    Date of Patent: February 5, 2013
    Assignee: Kosmek, Ltd.
    Inventors: Keitaro Yonezawa, Gaku Yoshimura, Yosuke Haruna
  • Patent number: 8302947
    Abstract: A clamp rod (6) inserted into a guide hole (5) of a housing (4) has: a clamping member (10); an inner piston (12); and a tapered pressure receiving surface (13), which are provided in this order in an axial direction from a left end to a right end. An output portion (26) for locking and releasing is provided on an inner periphery of a right end portion of one outer piston (23) inserted between the inner piston (12) and the guide hole (5). A collet (33) inserted between the pressure receiving surface (13) and the guide hole (5) is formed of four divided members (34) arranged circumferentially at substantially regular intervals. An input portion (36) driven by the output portion (26) and a pressing surface (40) which makes a wedge-engagement with the pressure receiving surface (13) from a right side are respectively provided in an outer periphery portion and on an inner periphery portion of each divided member (34).
    Type: Grant
    Filed: November 28, 2008
    Date of Patent: November 6, 2012
    Assignee: Kosmek Ltd.
    Inventors: Keitaro Yonezawa, Toshinao Nishimoto, Hironori Yamada