Patents by Inventor Takumi Nonaka

Takumi Nonaka 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).

  • Publication number: 20050039720
    Abstract: A carburetor with a single fuel system that is capable of ensuring stable engine operation and lower fuel consumption. The fuel system comprises an electrical fuel control C that, in addition to mechanically coordinating the fuel flow rate with air intake by way of a metering needle 22 that operates in coordination with the throttle valve 3, opens and closes opening/closing valve 30 and cuts off and delivers fuel to the air intake passage 2 so as to maintain a required target rotational speed with little fuel consumption in a specific region of the degrees of opening of the throttle valve 3. Stable operation with minimal fluctuations in the rotational speed is ensured by cutting off the fuel when the rotational speed rises above the target rotational speed, and delivering the fuel when the rotational speed falls below the target rotational speed.
    Type: Application
    Filed: July 28, 2004
    Publication date: February 24, 2005
    Inventor: Takumi Nonaka
  • Publication number: 20050035471
    Abstract: A flow rate control mechanism is provided to a low-speed fuel system that is independent from the main fuel system of a carburetor. The mechanism causes the valve element to move in a linear fashion by means of a cam coupled to the throttle stem. The mechanism increases the effective cross-sectional area of the low-speed fuel channel as the throttle valve opens from the idle position to the maximum degree of opening until the point in time at which the main fuel begins to flow, and thereafter causes the low-speed fuel flow rate to decrease and become zero in the high-output region. The transition from low-speed fuel to main fuel is made smooth, ensuring higher output and a stable fuel flow rate in the high-output region.
    Type: Application
    Filed: July 27, 2004
    Publication date: February 17, 2005
    Inventor: Takumi Nonaka
  • Publication number: 20050031473
    Abstract: A device that corrects with ease and high precision any deviation of the fuel flow rate due to variation in the constituent components of a carburetor, and to improve the exhaust condition and operability of an engine. A carburetor in which the delivery channel 23 and the suction channel 20 of a fuel pump 15 are connected with the aid of an escape channel 27, and in which a portion of the delivery fuel is allowed to escape to the suction side in order to prevent pressure exerted on the fuel valve 10 by the fuel delivered to the constant fuel chamber 5 from the fuel pump 15, which operates by pressure pulses, from reaching or exceeding a specified level, wherein the escape channel 27 is equipped with a manual control valve 29 for steplessly adjusting the surface area thereof.
    Type: Application
    Filed: August 7, 2003
    Publication date: February 10, 2005
    Inventor: Takumi Nonaka
  • Patent number: 6845972
    Abstract: The present invention facilitates the stabilization of the fuel flow rate in a single fuel system carburetor in which bleed air, mixed with fuel, is controlled by a metering needle moving in response to the movement of a throttle valve and the mixture is discharged into an intake channel. The present invention is directed to a carburetor in which an effective surface area of a metering hole is adjusted by a metering needle moving in response to the movement of a throttle valve, and the fuel introduced into a mixing chamber from a constant-fuel chamber under flow rate control with a metering hole is mixed with bleed air and discharged into an intake channel from a nozzle orifice. The mixing chamber has a volume providing for absorption and relaxation of changes in the negative pressure acting upon the nozzle orifice, the fuel is sucked in under stabilized negative pressure, and the air-fuel mixture with a preset air/fuel ratio is supplied over the entire operation range of the engine.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: January 25, 2005
    Assignee: Zama Japan
    Inventor: Takumi Nonaka
  • Patent number: 6843469
    Abstract: The present invention facilitates proper control of the scavenging air and fuel-air mixture for a stratified scavenging two-cycle engine that is based on a crankcase compression/scavenging method, using any carburetor. The present invention includes a drive member, which rotates based on an accelerator operation, installed on the air valve of the air passage, wherein the drive member is movable through angular reciprocal movements. A slave member, which constantly contacts a cam provided on the drive member is installed on the throttle valve of the carburetor, and wherein the slave member is movable through linear reciprocal movements. A fuel flow-rate controlling mechanism works in cooperation with these linear reciprocal movements.
    Type: Grant
    Filed: July 8, 2004
    Date of Patent: January 18, 2005
    Assignee: Zama Japan
    Inventor: Takumi Nonaka
  • Publication number: 20050001335
    Abstract: The present invention facilitates proper control of the scavenging air and fuel-air mixture for a stratified scavenging two-cycle engine that is based on a crankcase compression/scavenging method, using any carburetor. The present invention includes a drive member, which rotates based on an accelerator operation, installed on the air valve of the air passage, wherein the drive member is movable through angular reciprocal movements. A slave member, which constantly contacts a cam provided on the drive member is installed on the throttle valve of the carburetor, and wherein the slave member is movable through linear reciprocal movements. A fuel flow-rate controlling mechanism works in cooperation with these linear reciprocal movements.
    Type: Application
    Filed: July 8, 2004
    Publication date: January 6, 2005
    Inventor: Takumi Nonaka
  • Patent number: 6827338
    Abstract: The present invention facilitates proper control of the scavenging air and fuel-air mixture for a stratified scavenging two-cycle engine that is based on a crankcase compression/scavenging method, using any carburetor. The present invention includes a drive member, which rotates based on an accelerator operation, installed on the air valve of the air passage, wherein the drive member is movable through angular reciprocal movements. A slave member, which constantly contacts a cam provided on the drive member is installed on the throttle valve of the carburetor, and wherein the slave member is movable through linear reciprocal movements. A fuel flow-rate controlling mechanism works in cooperation with these linear reciprocal movements.
    Type: Grant
    Filed: September 26, 2003
    Date of Patent: December 7, 2004
    Assignee: Zama Japan
    Inventor: Takumi Nonaka
  • Publication number: 20040232569
    Abstract: The present invention facilitates increased output, decreased size, and simplified design and manufacture for a carburetor system in which a metering pin, which moves on a throttle valve, controls the fuel flow rate for a single fuel system. A carburetor of the present invention comprises a butterfly-like throttle valve on an air intake pathway with a nearly uniform diameter along its entire length, and a fuel nozzle positioned on the downstream side thereof. A metering pin retained by an actuating member that reciprocates linearly and remains in constant contact with a cam face of a cam member located on a valve stem. Fuel supplied to the air intake pathway from a constant fuel chamber via the fuel nozzle is controlled according to the opening and closing of a throttle. The metering pin by means of a cam controls the volume of the fuel flow rate at a desired stroke set irrespective of the opening and closing movement of the throttle valve.
    Type: Application
    Filed: June 16, 2004
    Publication date: November 25, 2004
    Applicant: ZAMA JAPAN
    Inventor: Takumi Nonaka
  • Patent number: 6755397
    Abstract: The present invention facilitates increased output, decreased size, and simplified design and manufacture for a carburetor system in which a metering pin, which moves on a throttle valve, controls the fuel flow rate for a single fuel system. A carburetor of the present invention includes a butterfly-like throttle valve on an air intake pathway with a nearly uniform diameter along its entire length, and a fuel nozzle positioned on the downstream side thereof. A metering pin retained by an actuating member that reciprocates linearly and remains in constant contact with a cam face of a cam member located on a valve stem. Fuel supplied to the air intake pathway from a constant fuel chamber via the fuel nozzle is controlled according to the opening and closing of a throttle. The metering pin by means of a cam controls the volume of the fuel flow rate at a desired stroke set irrespective of the opening and closing movement of the throttle valve.
    Type: Grant
    Filed: May 27, 2003
    Date of Patent: June 29, 2004
    Assignee: Zama Japan
    Inventor: Takumi Nonaka
  • Publication number: 20040104492
    Abstract: A device in which a needle-shaped valve element of a control valve is inserted into the throttle hole of a fuel channel to adjust the fuel flow rate. Accurate adjustments can be made with a small number of rotations of the control valve. A compensation channel 16 having a metering jet 17 for establishing the minimum required engine flow rate is provided to a valve element 13 of a manual control valve 12 that is inserted in a throttle hole 18 of a primary fuel channel 7. The flow rate is adjusted between the maximum required engine flow rate and the flow rate established by the compensation channel 16 in the gap between the external peripheral surface 13a of the valve element 13 and the entrance edge 18a of the throttle valve 18. Fuel can thereby be adjusted with a small number of rotations of the control valve 12. Accurate fine adjustment can be made with a small number of rotations even when the fine adjustment is achieved by reducing the taper angle of the conical portion 13A.
    Type: Application
    Filed: August 27, 2003
    Publication date: June 3, 2004
    Applicant: ZAMA JAPAN
    Inventors: Takumi Nonaka, Tamotsu Saito
  • Publication number: 20040075180
    Abstract: The present invention facilitates the stabilization of the fuel flow rate in a single fuel system carburetor in which bleed air, mixed with fuel, is controlled by a metering needle moving in response to the movement of a throttle valve and the mixture is discharged into an intake channel. The present invention is directed to a carburetor in which an effective surface area of a metering hole is adjusted by a metering needle moving in response to the movement of a throttle valve, and the fuel introduced into a mixing chamber from a constant-fuel chamber under flow rate control with a metering hole is mixed with bleed air and discharged into an intake channel from a nozzle orifice. The mixing chamber has a volume providing for absorption and relaxation of changes in the negative pressure acting upon the nozzle orifice, the fuel is sucked in under stabilized negative pressure, and the air-fuel mixture with a preset air/fuel ratio is supplied over the entire operation range of the engine.
    Type: Application
    Filed: September 29, 2003
    Publication date: April 22, 2004
    Applicant: ZAMA JAPAN
    Inventor: Takumi Nonaka
  • Publication number: 20040055546
    Abstract: The present invention facilitates proper control of the scavenging air and fuel-air mixture for a stratified scavenging two-cycle engine that is based on a crankcase compression/scavenging method, using any carburetor. The present invention includes a drive member, which rotates based on an accelerator operation, installed on the air valve of the air passage, wherein the drive member is movable through angular reciprocal movements. A slave member, which constantly contacts a cam provided on the drive member is installed on the throttle valve of the carburetor, and wherein the slave member is movable through linear reciprocal movements. A fuel flow-rate controlling mechanism works in cooperation with these linear reciprocal movements.
    Type: Application
    Filed: September 26, 2003
    Publication date: March 25, 2004
    Applicant: ZAMA JAPAN
    Inventor: Takumi Nonaka
  • Patent number: 6702262
    Abstract: The present invention facilitates the stabilization of the fuel flow rate in a single fuel system carburetor in which bleed air, mixed with fuel, is controlled by a metering needle moving in response to the movement of a throttle valve and the mixture is discharged into an intake channel. The present invention is directed to a carburetor in which an effective surface area of a metering hole is adjusted by a metering needle moving in response to the movement of a throttle valve, and the fuel introduced into a mixing chamber from a constant-fuel chamber under flow rate control with a metering hole is mixed with bleed air and discharged into an intake channel from a nozzle orifice. The mixing chamber has a volume providing for absorption and relaxation of changes in the negative pressure acting upon the nozzle orifice, the fuel is sucked in under stabilized negative pressure, and the air-fuel mixture with a preset air/fuel ratio is supplied over the entire operation range of the engine.
    Type: Grant
    Filed: March 14, 2002
    Date of Patent: March 9, 2004
    Assignee: Zama Japan
    Inventor: Takumi Nonaka
  • Publication number: 20040036184
    Abstract: A carburetor is provided that supplies an appropriate amount of fuel at engine start-up and in a specific range of rotational speed, and allows stable engine operation at a target rotational speed. The carburetor comprises a first fuel system F1 for metering fuel from the constant fuel chamber 18 with a metering needle 32 linked to a throttle valve 5, and delivering the fuel to an air intake passage 2; and a second fuel system F2 for controlling fuel compressed by a fuel pump 8 with an electromagnetically driven control valve 52 and delivering the fuel to the air intake passage 2; by supplying pressured fuel controlled by the control valve 52 in a predetermined specific range of rotation and controlling the rotational speed during start-up and warm-up, a target rotational speed can be maintained.
    Type: Application
    Filed: May 30, 2003
    Publication date: February 26, 2004
    Applicant: Zama Japan
    Inventor: Takumi Nonaka
  • Publication number: 20040035390
    Abstract: A carburetor with a single fuel system that is capable of ensuring stable engine operation and lower fuel consumption. The fuel system comprises an electrical fuel control C that, in addition to mechanically coordinating the fuel flow rate with air intake by way of a metering needle 22 that operates in coordination with the throttle valve 3, opens and closes opening/closing valve 30 and cuts off and delivers fuel to the air intake passage 2 so as to maintain a required target rotational speed with little fuel consumption in a specific region of the degrees of opening of the throttle valve 3. Stable operation with minimal fluctuations in the rotational speed is ensured by cutting off the fuel when the rotational speed rises above the target rotational speed, and delivering the fuel when the rotational speed falls below the target rotational speed.
    Type: Application
    Filed: May 23, 2003
    Publication date: February 26, 2004
    Applicant: Zama Japan
    Inventor: Takumi Nonaka
  • Patent number: 6681299
    Abstract: To provide a cache-tag control method capable of correcting an error and capable of keeping a high-speed operation of a system at the same time. A true-tag with a parity code attached and a shadow-tag having an inverted polarity of the true-tag are stored respectively in separate addresses within a cache tag-RAM. At the time of retrieving the tags, both the true-tag and the shadow-tag are checked respectively to see whether there is an error in each tag. When an error has been detected, a hit decision is made by using a tag in which there is no error. Further, data within the cache tag-RAM is updated by using the tag in which there is no error, thereby correcting the error.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: January 20, 2004
    Assignee: Fujitsu Limited
    Inventors: Takayuki Shimamura, Shinya Kato, Takato Noda, Takumi Nonaka
  • Patent number: 6662767
    Abstract: The present invention facilitates proper control of the scavenging air and fuel-air mixture for a stratified scavenging two-cycle engine that is based on a crankcase compression/scavenging method, using any carburetor. The present invention includes a drive member, which rotates based on an accelerator operation, installed on the air valve of the air passage, wherein the drive member is movable through angular reciprocal movements. A slave member, which constantly contacts a cam provided on the drive member is installed on the throttle valve of the carburetor, and wherein the slave member is movable through linear reciprocal movements. A fuel flow-rate controlling mechanism works in cooperation with these linear reciprocal movements.
    Type: Grant
    Filed: July 9, 2002
    Date of Patent: December 16, 2003
    Assignee: Zama Japan
    Inventor: Takumi Nonaka
  • Publication number: 20030201551
    Abstract: The present invention facilitates increased output, decreased size, and simplified design and manufacture for a carburetor system in which a metering pin, which moves on a throttle valve, controls the fuel flow rate for a single fuel system. A carburetor of the present invention comprises a butterfly-like throttle valve on an air intake pathway with a nearly uniform diameter along its entire length, and a fuel nozzle positioned on the downstream side thereof. A metering pin retained by an actuating member that reciprocates linearly and remains in constant contact with a cam face of a cam member located on a valve stem. Fuel supplied to the air intake pathway from a constant fuel chamber via the fuel nozzle is controlled according to the opening and closing of a throttle. The metering pin by means of a cam controls the volume of the fuel flow rate at a desired stroke set irrespective of the opening and closing movement of the throttle valve.
    Type: Application
    Filed: May 27, 2003
    Publication date: October 30, 2003
    Applicant: ZAMA JAPAN
    Inventor: Takumi Nonaka
  • Patent number: 6631889
    Abstract: The present invention facilitates increased output, decreased size, and simplified design and manufacture for a carburetor system in which a metering pin, which moves on a throttle valve, controls the fuel flow rate for a single fuel system. A carburetor of the present invention includes a butterfly-like throttle valve on an air intake pathway with a nearly uniform diameter along its entire length, and a fuel nozzle positioned on the downstream side thereof. A metering pin retained by an actuating member that reciprocates linearly and remains in constant contact with a cam face of a cam member located on a valve stem. Fuel supplied to the air intake pathway from a constant fuel chamber via the fuel nozzle is controlled according to the opening and closing of a throttle. The metering pin by means of a cam controls the volume of the fuel flow rate at a desired stroke set irrespective of the opening and closing movement of the throttle valve.
    Type: Grant
    Filed: March 8, 2002
    Date of Patent: October 14, 2003
    Assignee: Zama Japan
    Inventor: Takumi Nonaka
  • Publication number: 20030173686
    Abstract: The present invention facilitates the stabilization of the fuel flow rate in a single fuel system carburetor in which bleed air, mixed with fuel, is controlled by a metering needle moving in response to the movement of a throttle valve and the mixture is discharged into an intake channel. The present invention is directed to a carburetor in which an effective surface area of a metering hole is adjusted by a metering needle moving in response to the movement of a throttle valve, and the fuel introduced into a mixing chamber from a constant-fuel chamber under flow rate control with a metering hole is mixed with bleed air and discharged into an intake channel from a nozzle orifice. The mixing chamber has a volume providing for absorption and relaxation of changes in the negative pressure acting upon the nozzle orifice, the fuel is sucked in under stabilized negative pressure, and the air-fuel mixture with a preset air/fuel ratio is supplied over the entire operation range of the engine.
    Type: Application
    Filed: March 14, 2002
    Publication date: September 18, 2003
    Applicant: Zama Japan
    Inventor: Takumi Nonaka