Patents by Inventor Ken Yamamoto

Ken Yamamoto 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: 6233969
    Abstract: In a decompression device-integrated heat exchanger, a pressure-reducing unit for reducing high-pressure refrigerant of a refrigerant cycle, and an inner heat-exchanging unit for performing heat-exchange between high-pressure refrigerant before being decompressed in the pressure-reducing unit and low-pressure refrigerant after being decompressed in the pressure reducing unit are integrated to each other. The inner heat-exchanging unit has a high-pressure tube through which high-pressure refrigerant flows, and a low-pressure tube through which low-pressure refrigerant flows. Both the tubes are wound around a case of the pressure-reducing unit, and are brazed to the case on contacting portions therebetween. Further, in each tube, wall thickness of the contacting portion is made thinner than that of the other portion. Thus, the decompression device-integrated heat exchanger has a reduced weight, while having a simple structure.
    Type: Grant
    Filed: December 8, 1999
    Date of Patent: May 22, 2001
    Assignee: Denso Corporation
    Inventors: Yoshiyuki Yamauchi, Ken Yamamoto, Minoru Ohta
  • Patent number: 6216776
    Abstract: A heat exchanger has plural flat tubes through which refrigerant flows, and a pair of header tanks disposed on each longitudinal ends of the flat tubes. Each of the flat tubes has a flow passage portion having plural flow passages through which refrigerant flows, and a non-flow passage portion disposed on both sides of the flow passage portion, having at least one non-flow passage through which no refrigerant flows. The flow passage portion is inserted into the header tank so that the flow passages communicate with the header tank, and the non-flow passage portion is exposed outside the header tank. Each of the flow passages has a circular-shaped cross-section while the non-flow passage has a polygonal-shaped cross-section, so that a wall thickness of the non-flow passage is made thinner than that of the flow passages. Therefore, weight of the flat tube is decreased, while sufficient strength thereof is maintained.
    Type: Grant
    Filed: February 5, 1999
    Date of Patent: April 17, 2001
    Assignee: Denso Corporation
    Inventors: Osamu Kobayashi, Ken Yamamoto, Yoshiyuki Yamauchi, Kazuhiro Mitsukawa
  • Patent number: 6189604
    Abstract: A heat exchanger in which refrigerant flows has a first core portion disposed in a first air passage for exchanging heat with inside air and a second core portion for exchanging heat with outside air. The second core portion is disposed at a downstream side of the first core portion in a refrigerant flow direction. Accordingly, refrigerant exchanges heat with inside air, first, and then exchanges heat with outside air, a temperature of which is lower than that of inside air. Further, refrigerant flows to form an opposed flow with respect to an air flow direction in the respective first and second core portions. As a result, heating performance of the heat exchanger is improved.
    Type: Grant
    Filed: January 18, 2000
    Date of Patent: February 20, 2001
    Assignee: Denso Corporation
    Inventors: Yoshiyuki Yamauchi, Osamu Kobayashi, Ken Yamamoto
  • Patent number: 6176303
    Abstract: A radiator includes a plurality of flat tubes in which refrigerant flows, corrugated fins each of which is disposed between adjacent the flat tubes, and a header tank disposed at both end sides of each flat tube in a longitudinal direction of the flat tubes. A plurality of insertion holes into which the flat tubes are inserted are formed in a tank portion of the header tank, and each of the insertion holes has a hole width approximately equal to a tank width of the header tank in a width direction perpendicular to both of the longitudinal direction of the flat tubes and an extending direction of the header tank. The tank portion of the header tank is integrally formed from extruding or drawing, and the insertion holes are formed by shaving the tank portion after the extruding or drawing. Thus, the insertion holes can be readily provided in the tank portion integrally formed from the extruding or the drawing, and pressure tightness and manufacturing workability of the header tank can be improved.
    Type: Grant
    Filed: February 1, 1999
    Date of Patent: January 23, 2001
    Assignee: Denso Corporation
    Inventors: Osamu Kobayashi, Yoshiyuki Yamauchi, Ken Yamamoto
  • Patent number: 6125922
    Abstract: A refrigerant condenser is set so that, if its condensation distance is L, the equivalent diameter of a tube having a linearly configured passage for the purpose of heat exchange is de (each dimension being in units of mm), and the number of times the direction change of the linearly configured passage for the purpose of heat exchange change is N, with de.ltoreq.1.15 and the relationship L=(N+1)W=400+1,180 de to 700+1,180 de satisfied, a high heat exchange efficiency is achieved. In this refrigerant condenser, it is possible to use a single long winding tube.
    Type: Grant
    Filed: June 13, 1997
    Date of Patent: October 3, 2000
    Assignee: Nippondenso Co., Ltd.
    Inventors: Michiyasu Yamamoto, Ken Yamamoto, Ryouichi Sanada
  • Patent number: 6109228
    Abstract: A valve lifter includes a guide cap mounted between a cam and the top end of a valve stem and which is slidably supported so as to be capable of moving in the axial direction. The guide cap has an end wall formed with a threaded through-hole. An adjusting bolt is threadedly engaged in the threaded hole. The adjusting bolt is biased toward the valve stem by a spring. The threaded hole and the adjusting bolt have serration-shaped threads so that the adjusting bolt can be moved toward the valve stem under the force of the spring. Since the adjusting bolt is threaded into the threaded hole formed in the guided cap, the axial length of the valve lifter is short.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: August 29, 2000
    Assignee: NTN Corporation
    Inventors: Ken Yamamoto, Takashi Nozaki
  • Patent number: 6032630
    Abstract: A direct valve drive device which can open and lose a valve with accuracy even if a negative valve clearance forms between the cam and the valve stem due to a difference in thermal expansion coefficient between the cylinder head made of aluminum alloy and the iron valve. A valve lifter is mounted between the cam and the valve stem being biased toward the cam by a valve spring. An adjuster bolt is threaded into a threaded hole formed in the valve lifter. The force of a spring is applied to the adjuster bolt so that the adjuster bolt move, while rotating, toward the valve stem. Formed between the threadedly engaging portions of the adjuster bolt and the threaded hole is an axial hole which is smaller than the height of a ramp formed on the cam but large enough to absorb any difference in thermal expansion between the cylinder head and the valve.
    Type: Grant
    Filed: November 13, 1998
    Date of Patent: March 7, 2000
    Assignee: NTN Corporation
    Inventors: Ken Yamamoto, Takashi Nozaki
  • Patent number: 6003592
    Abstract: A refrigerant condenser set so that a condensation distance L (mm) of the condenser falls between 400+1180 de and 700+1180 de where de (mm) is the equivalent diameter of the tubes forming the core. By setting the condensation distance L in this way, the heat exchange rate becomes higher and it is possible to determine the number of turns required for the distance L.
    Type: Grant
    Filed: December 12, 1995
    Date of Patent: December 21, 1999
    Assignee: Denso Corporation
    Inventors: Michiyasu Yamamoto, Ken Yamamoto, Ryouichi Sanada
  • Patent number: 5961410
    Abstract: An autotensioner which can keep the tension in a belt at a constant level from the start of an engine. The autotensioner includes a cylinder having a top opening closed by an oil seal to prevent leakage of hydraulic oil in the cylinder. A rod slidably extends through the oil seal and is biased upward by a rod spring. At the bottom end of the rod is a hydraulic damper. A screw rod is slidably fitted on a small-diameter portion at the bottom end of the rod and is urged by a return spring against a shoulder formed on the rod. A nut member is axially immovably mounted in the cylinder while kept in mesh with a male thread formed on the screw rod. When the engine is cut, the belt may be stretched according to the positions of the cam on camshafts. If this happens, the rod is pushed inwardly by the belt. This rod pushing force is borne by pressure flanks of the threads at the thread engagement portions of the screw rod and the nut member to prevent the retraction of the rod.
    Type: Grant
    Filed: October 15, 1997
    Date of Patent: October 5, 1999
    Assignee: NTN Corporation
    Inventor: Ken Yamamoto
  • Patent number: 5924485
    Abstract: An inside wall surface of a cap covering the end portion of a header tank is formed into a spherical shape, and a connecting portion between the inside wall surface of the cap and a inside wall surface of a tank portion is separated away from a connecting portion between the inside wall surface of the tank portion and an outside wall surface of a tube. Thus, the brazing material is suctioned into both connecting portions (both gaps) sufficiently, and both connecting portions are brazed firmly.
    Type: Grant
    Filed: May 7, 1998
    Date of Patent: July 20, 1999
    Assignee: Denso Corporation
    Inventors: Osamu Kobayashi, Ken Yamamoto
  • Patent number: 5909766
    Abstract: A heat exchanger has a plurality of tubes and tank portions formed by a plurality of first thin plates laminated and connected to each other, and a plurality of covering members formed by a plurality of second thin plates laminated and connected to each other. The covering members cover the tubes and the tank portions while forming a plurality of openings therebetween. Each of the first thin plates has a communication hole so that each of the openings communicates with each other. An electromagnetic valve is disposed in the heat exchanger to control a communication between the opening and an outer space of the heat exchanger. Thus, when any one of the tubes and the tank portions cracks and leaks refrigerant flowing therethrough, refrigerant is collected into the openings and is accurately rapidly discharged to the outer space by an opening operation of the electromagnetic valve.
    Type: Grant
    Filed: June 29, 1998
    Date of Patent: June 8, 1999
    Assignee: Denso Corporation
    Inventors: Osamu Kobayashi, Ken Yamamoto
  • Patent number: 5879255
    Abstract: A chain tensioner including a housing having a cylinder chamber, a rod member in the form of a threaded shaft inserted in the cylinder chamber for tensioning a chain, a tension adjusting spring for biasing the rod member outwardly of the housing, a hydraulic damper for damping axial dynamic load applied to the rod member from the chain by utilizing as a damping medium a hydraulic oil supplied into a closed end of the cylinder chamber through an oil supply passage formed in the housing and a check valve, and a thread engagement arrangement for preventing the rod member from retracting under an axial static load applied to the rod member. The chain tensioner can prevent the entry of air in the pressure chamber of the hydraulic damper when the engine is started in a cold environment or restarted.
    Type: Grant
    Filed: April 16, 1997
    Date of Patent: March 9, 1999
    Assignee: NTN Corporation
    Inventors: Ken Yamamoto, Katsuhisa Suzuki
  • Patent number: 5799749
    Abstract: A rotation transmission device has a driving member and a driven member rotatably mounted one inside the other. A plurality of engaging elements are mounted between the driving member and the driven member so as to engage with the driving member and the driven member when the driving member and the driven member rotate relative to each other in either direction. A cage is mounted between the driving member and the driven member for keeping the engaging elements apart from one another by a predetermined distance. A turning force imparting mechanism is coupled to the cage for moving the engaging elements to an engageable position by turning the cage in one direction relative to the driving member, and a locking mechanism is provided between the cage and the driven member for detachably coupling the cage to the driven member and remote-controlled through a cable connected to the locking mechanism and extending out of the rotation transmission device.
    Type: Grant
    Filed: June 30, 1995
    Date of Patent: September 1, 1998
    Assignee: NTN Corporation
    Inventors: Ken Yamamoto, Kenichiro Itoh, Isao Hori, Kohji Akiyoshi
  • Patent number: 5740893
    Abstract: An outer ring 3 along a bearing centerline of the bearing outer ring of a standard deep groove ball bearing, and the bottom of the raceway surface 3b1 is formed with a circumferential groove 3b2. A retainer 3d is fitted in the circumferential groove 3b2 of the outer ring 3b. The retainer 3d is in the form of a split ring having a single split and has a cam surface on the wall surface on the pocket side.
    Type: Grant
    Filed: June 3, 1996
    Date of Patent: April 21, 1998
    Assignee: NTN Corporation
    Inventor: Ken Yamamoto
  • Patent number: 5732807
    Abstract: An automotive power transmission device which can change over the driving mode between two-wheel drive and four-wheel drive mode. The device when combined with a differential as an integral unit can be assembled easily. This device includes an axle made up of axially separated first and second portions, a differential coupled to one end of the first portion of the axle and having a differential cover, and a clutch device coupled to the other end of the first portion of the axle which is enclosed in the differential cover. The clutch includes an inner ring connected to the differential, an outer ring connected to a vehicle wheel and rotatably mounted around the inner ring, sprags and cages mounted between the inner and outer rings, a biasing member for biasing and rotating the cages relative to the inner ring, and a locking system for detachably coupling the cage and the outer ring together. While the transfer is set in the two-wheel drive mode, the outer ring is allowed to free-run.
    Type: Grant
    Filed: January 24, 1996
    Date of Patent: March 31, 1998
    Assignee: NTN Corporation
    Inventors: Kenichiro Itoh, Ken Yamamoto, Isao Hori
  • Patent number: 5730212
    Abstract: A refrigerant condenser is set so that, if its condensation distance is L, the equivalent diameter of a tube having a linearly configured passage for the purpose of heat exchange is de (each dimension being in units of mm), and the number of times the direction change of the linearly configured passage for the purpose of heat exchange change is N, with de.ltoreq.1.15 and the relationship L=(N+1)W=400+1,180 de to 700+1,180 de satisfied, a high heat exchange efficiency is achieved. In this refrigerant condenser, it is possible to use a single long winding tube.
    Type: Grant
    Filed: December 30, 1996
    Date of Patent: March 24, 1998
    Assignee: Nippondenso Co., Ltd.
    Inventors: Michiyasu Yamamoto, Ken Yamamoto, Ryouichi Sanada
  • Patent number: 5713809
    Abstract: A chain tensioner keeps constant the tension of a chain for transmitting the rotation of an engine crankshaft to e.g. camshafts. It includes a housing having a cylinder chamber. A rod member has its rear end inserted in the cylinder chamber for pressing a chain. A tension adjusting spring biases the rod member outwardly of the housing. The chain tensioner further includes a hydraulic damper for damping a dynamic load applied to the rod member from the chain, and a thread engagement mechanism for preventing the rod member from retracting under a static load applied to the rod member.
    Type: Grant
    Filed: February 26, 1997
    Date of Patent: February 3, 1998
    Assignee: NTN Corporation
    Inventors: Ken Yamamoto, Katsuhisa Suzuki, Kazuki Kawashima, Tsuyoshi Niwa
  • Patent number: 5682944
    Abstract: A refrigerant condenser is set so that, if its condensation distance is L, the equivalent diameter of a tube having a linearly configured passage for the purpose of heat exchange is de (each dimension being in units of mm), and the number of times the direction change of the linearly configured passage for the purpose of heat exchange change is N, with de.ltoreq.1.15 and the relationship L=(N+1)W=400+1,180 de to 700+1,180 de satisfied, a high heat exchange efficiency is achieved. In this refrigerant condenser, it is possible to use a single long winding tube.
    Type: Grant
    Filed: June 23, 1995
    Date of Patent: November 4, 1997
    Assignee: Nippondenso Co., Ltd.
    Inventors: Michiyasu Yamamoto, Ken Yamamoto, Ryouichi Sanada
  • Patent number: 5632474
    Abstract: A hydraulic autotensioner has a cylinder having a closed bottom end, a sleeve mounted in the cylinder and a plunger slidably mounted in the sleeve. The interior of the cylinder is divided into a reservoir chamber and a pressure chamber by the plunger which is formed with a passage through which the reservoir chamber and the pressure chamber communicate with each other. A check valve is provided in the passage to close the passage if the pressure of hydraulic oil in the pressure chamber increases above the pressure of hydraulic oil in the reservoir chamber. A return spring is mounted in the cylinder to bias a rod which is axially movable together with the plunger in such a direction as to protrude from an upper opening of the cylinder. The return spring is mounted in a space formed between the outer peripheral surface of the sleeve and the inner peripheral surface of the cylinder.
    Type: Grant
    Filed: October 4, 1995
    Date of Patent: May 27, 1997
    Assignee: NTN Corporation
    Inventors: Hisashi Hayakawa, Kazuki Kawashima, Norio Yamazaki, Ken Yamamoto, Satoshi Kitano
  • Patent number: 5617691
    Abstract: A fitting structure of a plurality of rectangular parallelopipedal blocks comprising concavo-convexities formed on the surfaces of each of the blocks. The concavo-convexities are formed on each surface of the block on the basis of a figure which is in symmetry of rotation per 90.degree. round the center of a regular square or is in symmetry of rotation per 180.degree. round the center of a rectangle, and is complementarily in symmetry of axis with respect to a center of the rectangle line passing through the center and being in parallel with a side of the regular square or rectangle. Predetermined congruence is imparted to the figures on the surfaces depending on various shapes of the blocks. Fitting of the concavo-convexities of the surfaces of the adjacent blocks is always ensured when each block is aligned so that its thickness and its length are in conformity. The surfaces of adjacent blocks can be connected without the necessity of considering the direction of each block.
    Type: Grant
    Filed: April 13, 1995
    Date of Patent: April 8, 1997
    Assignee: Doryokuro Kakunenryo Kaihatsu Jigyodan
    Inventor: Ken Yamamoto