Patents by Inventor Tetsushi Saito

Tetsushi Saito 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: 5836274
    Abstract: A number of embodiments of twin overhead cam shaft reciprocating machines having a plurality of poppet valves. A variable valve timing mechanism is interposed between the cam shafts and respective of the poppet valves for varying their lift and for changing the number of effective poppet valves per cylinder. The lift changing mechanism includes means for shifting at least one rocker arm follower and provides a relatively compact yet highly efficient structure for achieving this purpose.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: November 17, 1998
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Tetsushi Saito, Hiroyuki Tsuzuku, Naoki Tsuchida
  • Patent number: 5809963
    Abstract: A cooling and lubricating system for an internal combustion engine wherein an oil cooler and oil filter are mounted at a lower portion of the cylinder block in a recess formed by the crankcase member to provide a compact assembly and wherein the oil filter is readily accessible. All of the passages for supplying lubricant and coolant to and from the oil cooler and oil filter are formed integrally in the body of the engine so as to avoid the use of external conduits.
    Type: Grant
    Filed: January 24, 1997
    Date of Patent: September 22, 1998
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Tetsushi Saito
  • Patent number: 5809953
    Abstract: A number of embodiments of twin overhead cam shaft reciprocating machines having a plurality of poppet valves. A variable valve timing mechanism is interposed between the cam shafts and respective of the poppet valves for varying their lift and for changing the number of effective poppet valves per cylinder. The lift changing mechanism includes means for shifting at least one rocker arm follower and provides a relatively compact yet highly efficient structure for achieving this purpose.
    Type: Grant
    Filed: October 8, 1997
    Date of Patent: September 22, 1998
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Tetsushi Saito, Hiroyuki Tsuzuku, Naoki Tsuchida
  • Patent number: 5785017
    Abstract: A number of embodiments of twin overhead cam shaft reciprocating machines having a plurality of poppet valves. A variable valve timing mechanism is interposed between the cam shafts and respective of the poppet valves for varying their lift and for changing the number of effective poppet valves per cylinder. The lift changing mechanism includes means for shifting at least one rocker arm follower and provides a relatively compact yet highly efficient structure for achieving this purpose.
    Type: Grant
    Filed: April 10, 1996
    Date of Patent: July 28, 1998
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Tetsushi Saito, Hiroyuki Tsuzuku, Naoki Tsuchida
  • Patent number: 5758612
    Abstract: A number of embodiments of multiple-valve internal combustion engines having at least some of the valves being deactivatable by means of a hydraulic tappet assembly so as to control the flow path and flow pattern into and out of the combustion chamber. A hydraulic system is provided for controlling which of the valves operate and, if desired, the lift of the valves.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: June 2, 1998
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Hiroyuki Tsuzuku, Tetsushi Saito, Naoki Tsuchida
  • Patent number: 5647315
    Abstract: A cooling and lubricating system for an internal combustion engine wherein an oil cooler and oil filter are mounted at a lower portion of the cylinder block in a recess formed by the crankcase member to provide a compact assembly and wherein the oil filter is readily accessible. All of the passages for supplying lubricant and coolant to and from the oil cooler and oil filter are formed integrally in the body of the engine so as to avoid the use of external conduits.
    Type: Grant
    Filed: October 4, 1995
    Date of Patent: July 15, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Tetsushi Saito
  • Patent number: 5606942
    Abstract: A number of embodiments of overhead cam internal combustion engines having multiple intake and exhaust valves. The valve actuating mechanism is such that the valves are opened at a non-symmetrical rate so as to minimize the clearance requirements at top dead center and also so as to minimize the overlap between the closing of the exhaust valve and the opening of the intake valve without decreasing volumetric efficiency. A number of embodiments having either direct or rocker arm actuation are disclosed.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 4, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Hiroyuki Tsuzuku, Tetsushi Saito, Naoki Tsuchida
  • Patent number: 5503117
    Abstract: A number of embodiments of engine construction having chain-driven overhead camshafts closed by a timing case cover and which timing case cover forms at least in part a coolant pump to the engine. Various arrangement for circulating the liquid coolant through the engine and an oil cooler mounted at the base of the engine are disclosed.
    Type: Grant
    Filed: October 28, 1994
    Date of Patent: April 2, 1996
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Tetsushi Saito
  • Patent number: 5231961
    Abstract: An improved camshaft and accessory drive arrangement for a V type engine wherein pairs of overhead cams are driven from the crankshaft by means of intermediate shafts that are directly driven by the crankshaft. The axis of rotation of the intermediate shafts is disposed closer to the axis of rotation of the crankshaft than the axes of rotation of the camshafts. An accessory is positioned in the valley of the V and is also driven by the crankshaft but is spaced further from the crankshaft axis of rotation than the intermediate shafts. This accessory is a water pump and an oil pump is also driven by the crankshaft at the same end of the engine.
    Type: Grant
    Filed: January 19, 1990
    Date of Patent: August 3, 1993
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Kazuo Shimada, Tatsuo Niiyama, Tetsushi Saito
  • Patent number: 5161495
    Abstract: A lubrication arrangement for an engine and more particularly to an arrangement for lubricating the valve train of an engine. The valve train includes a cylinder head that journals an intake and an exhaust camshaft through bearings formed in the cylinder head and the cam cover. Hydraulic lash adjusters are associated with each of the camshafts and there are more intake adjusters than exhaust adjusters. An arrangement is provided for delivering lubricant to the lash adjusters and the camshaft journals which includes a passageway formed in the cam cover. Lubricant is delivered to the cylinder head in proximity to the intake adjusters so that the intake adjusters and the exhaust adjusters will receive lubricant at substantially the same pressure.
    Type: Grant
    Filed: February 10, 1992
    Date of Patent: November 10, 1992
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Tetsushi Saito
  • Patent number: 5125374
    Abstract: A valve arrangement for a cylinder head assembly employing three intake valves and two exhaust valves for each cylinder. Not all of the intake valves reciprocate along parallel axes and hydraulic adjusters are operatively associated with the camshafts and rocker arms that operate the valves from the respective camshafts. The geometric relationship of the valves is chosen so as to maintain a compact and effective combustion chamber configuration and facilitate machining of the bores in which the hydraulic adjusters are positioned.
    Type: Grant
    Filed: July 10, 1990
    Date of Patent: June 30, 1992
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Tetsushi Saito
  • Patent number: 5121718
    Abstract: A cylinder head construction for an internal combustion engine that permits a large number of valves to be employed and good bearing surface without interfering with the insertion or removal of the multiple valve springs. This is accomplished by providing a relief in one of the camshaft journals that is juxtaposed to one of the valves so that the valve spring can be easily inserted and removed. In addition, the seating area for the valve springs in the cylinder head is machined to a diameter smaller than the diameter of the valve springs and a spring seating member is interposed between this cylinder head surface and the adjacent end of the valve spring and has a diameter at least equal to that of the valve spring.
    Type: Grant
    Filed: July 13, 1990
    Date of Patent: June 16, 1992
    Inventor: Tetsushi Saito
  • Patent number: RE35382
    Abstract: A lubrication arrangement for an engine and more particularly to an arrangement for lubricating the valve train of an engine. The valve train includes a cylinder head that journals an intake and an exhaust camshaft through bearings formed in the cylinder head and the cam cover. Hydraulic lash adjusters are associated with each of the camshafts and there are more intake adjusters than exhaust adjusters. An arrangement is provided for delivering lubricant to the lash adjusters and the camshaft journals which includes a passageway formed in the cam cover. Lubricant is delivered to the cylinder head in proximity to the intake adjusters so that the intake adjusters and the exhaust adjusters will receive lubricant at substantially the same pressure.
    Type: Grant
    Filed: August 29, 1994
    Date of Patent: November 26, 1996
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Tetsushi Saito