Patents Assigned to Yamaha Hatsudoki
  • Patent number: 5617822
    Abstract: An improved lubrication system for a two-stroke engine having a lubrication path from an oil sump directly to an induction valve assembly for noise reduction. The oil sump is divided into two chambers with a restricted passage therebetween to ensure lubrication of transmission gears upon startup while reducing drag during operation. A cross-drilled lubrication passage through each crankshaft throw terminates in a second passage proximate a dead-end plug, the second passage being in communication with the piston rod bearing. Each piston skirt includes at least one axial groove in registration with an oil supply passage. Circumferential grooves distribute the oil around the piston skirt from the axial grooves. The pistons may include ceramic top layers for heat insulation to increase the compression ratio possible by raising the ring positions. The engine incorporates an air/oil mixture separator within a balancer shaft chamber and air from the chamber is directed to the intake system.
    Type: Grant
    Filed: August 11, 1995
    Date of Patent: April 8, 1997
    Assignee: Yamaha Hatsudoki kabushiki Kaisha
    Inventor: Tatsuyuki Masuda
  • Patent number: 5619328
    Abstract: The invention is adapted to be embodied in a component measuring system for measuring a component in an optical detecting station. A pick up device is supported for movement in a first direction and is rotatable about an axis. An optical detection station having an optical range limited in height is defined by a plurality of parallel light rays. The pick up device moves a component held thereby into the optical range. The device measures at least one dimension of said first area of said component and determines whether this area was correctly measured.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: April 8, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Hiroshi Sakurai
  • Patent number: 5618322
    Abstract: A number of embodiments of reformers for reforming fuel for a fuel cell that includes an elongated catalyst bed with fuel to be reformed being delivered at one end of the bed and extracted from the other end of the bed. Heat is applied to a greater extent at the inlet end of the catalyst bed than the outlet end to prevent the formation of carbon monoxide in the products delivered from the outlet. In all embodiments, the catalyst bed has a spiral configuration and the fuel is heated before it is delivered to the catalyst bed. In some embodiments the same heat sources are employed for heating both the fuel and the catalyst bed.
    Type: Grant
    Filed: February 14, 1994
    Date of Patent: April 8, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Yutaka Mizuno, Toshiharu Hanajima, Hisayoshi Matsubara
  • Patent number: 5615661
    Abstract: A feedback fuel control circuit for an engine to maintain a stoichiometric fuel/air ratio through adjustment of the fuel supply system. The system operates with a sensor that does not output a signal until the engine temperature is more than a predetermined temperature. Therefore, during the times when the output engine combustion sensor is not at its operating temperature the feedback control is disabled and a lean fuel air mixture is supplied to the engine. This mixture is temporarily enriching during the warmup cycle to determine if the combustion sensor outputs a signal and when it does the system switches to feedback control.
    Type: Grant
    Filed: August 7, 1995
    Date of Patent: April 1, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Toshio Suzuki
  • Patent number: 5613468
    Abstract: A fuel injection system for an engine having a reed type valve in the induction system. The injection system is designed and controlled so that the fuel that is injected is injected substantially entirely before the reed type valve is closed. The time of closing of the reed type valve is determined either by measuring the pressure differential or by recording data indicative of the valve closing in response to various engine running conditions such as speed and/or load.
    Type: Grant
    Filed: April 19, 1996
    Date of Patent: March 25, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Takeru Ibara, Yoshihiko Moriya, Yu Motoyama
  • Patent number: 5613887
    Abstract: A number of embodiments of jet-propelled watercraft embodying a combined jet propulsion unit and propulsion unit condition sensor. The condition sensor is contained within the outer housing of the jet propulsion unit and may be formed either in the grilled inlet opening, the water inlet portion, the straightening vane portion, or the discharge nozzle portion.
    Type: Grant
    Filed: March 31, 1995
    Date of Patent: March 25, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Noboru Kobayashi
  • Patent number: 5606952
    Abstract: A number of embodiments of engine control systems wherein the engine speed is controlled during a range of movement from idle to a pick-up position by varying primarily the spark timing and thereafter the throttle valve is opened. The throttle valve is maintained in its idle position in a partially open position which will permit greater air flow than required for idle and the speed is controlled by retarding the spark. In addition, further spark retardation is accomplished if the temperature of the engine is below a predetermined minimum desired operating condition for transferring more fuel energy to engine heating than power output for promoting more rapid warmup.
    Type: Grant
    Filed: November 6, 1995
    Date of Patent: March 4, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Isao Kanno, Masahiko Kato
  • Patent number: 5608642
    Abstract: The invention is a method of determining whether a pick up apparatus has picked up a component in a normal manner. The method includes picking up a component with the apparatus, detecting at least one dimension of a projected image with of the component with an optical detector and determining whether the component has been picked up normally by determining whether the dimension of said projected image, less a correction factor based on the diffraction of light, is within a tolerance range.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: March 4, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Hitoshi Onodera
  • Patent number: 5607332
    Abstract: A number of embodiments of jet propelled watercraft having an improved pedal operated reverse thrust bucket mechanism. The pedal for operating the reverse thrust bucket is positioned so that it is generally flush with the floor area when the reverse thrust bucket is in its forward drive mode and can be depressed into a recessed area of the floor area for effecting trim or reverse thrust operation of the reverse thrust bucket. In this way, the pedal does not obscure the rider's foot area but is still readily accessible for the rider.
    Type: Grant
    Filed: December 23, 1994
    Date of Patent: March 4, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Noboru Kobayashi, Tomoyoshi Koyanagi
  • 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: 5605119
    Abstract: An exhaust control valve arrangement for a two cycle internal combustion engine for altering the compression ratio to provide optimum running under all conditions. An arrangement is provided or cleaning the exhaust control valve and its surrounding cooperating surfaces of the engine upon shutting off of the engine to preclude the formations of deposits that can cause sticking of the valve element. The valve element is rotated through a number of cycles after the engine is stopped through a wider range than during its normal valving operation for removing deposits. The number of cycles is chosen in response to an engine condition such as length of time of running or amount of lubricant supplied to the engine. Various valve arrangements are disclosed that improve the cleaning operation and permit cleaning even while the engine is running.
    Type: Grant
    Filed: January 30, 1995
    Date of Patent: February 25, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Tatsuyuki Masuda, Kousei Maebashi, Michihisa Nakamura, Hidenori Suhara
  • Patent number: 5603644
    Abstract: A number of embodiments of jet propelled watercrafts having reverse thrust mechanisms and wherein an indicator is provided for indicating to following watercraft when the watercraft is being rapidly braked or rapidly turned. The watercraft has adjacent throttle and shift lever controls and various control lever positions are disclosed for facilitating ease of operation and compact construction.
    Type: Grant
    Filed: October 11, 1991
    Date of Patent: February 18, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Noboru Kobayashi, Yoshiki Futaki
  • Patent number: 5603301
    Abstract: A fuel injection system for a multi-valve internal combustion engine that includes an arrangement for controlling the fuel spray in response to engine load and speed. As a result, it is possible to obtain stratification under low-speed, low-load conditions and a homogeneous mixture under high-speed, high-load conditions.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: February 18, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Kenichi Sakurai, Makoto Kawamura
  • Patent number: 5601044
    Abstract: A sailboat having an improved mast and boom arrangement wherein the mast is pivotally supported relative to the hull about an axis that is disposed rearwardly from the mast and close to but in front of the normal center of pressure on the sail carried thereby so as to reduce the turning moments on the hull during sailing and improve the speed performance. An improved pivotal arrangement for the boom is disclosed, as is a pivotal connection between the mast and the boom which permits the mast to be easily raised and lowered.
    Type: Grant
    Filed: August 4, 1995
    Date of Patent: February 11, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Ioki Hara
  • Patent number: 5600861
    Abstract: Several embodiments of burr removal arrangements for cleaning castings. The burr removal comprises one or more wire brushes that are spring biased into engagement with the casting surface. In some embodiments, there are a plurality of brushes, and adjacent brushes rotate in opposite directions.
    Type: Grant
    Filed: December 15, 1994
    Date of Patent: February 11, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Shoji Saito
  • Patent number: 5598813
    Abstract: An exhaust control drive arrangement for an internal combustion engine for varying the exhaust port timing and effective compression ratio. The exhaust control valve is driven by a servomechanism mounted directly on the cylinder block at one end of the engine and adjacent the flywheel so as to provide a compact assembly.
    Type: Grant
    Filed: June 9, 1994
    Date of Patent: February 4, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Tatsuyuki Masuda, Minoru Iida
  • Patent number: 5597051
    Abstract: A lubricating system for a machine such as a two-cycle internal combustion engine including a reciprocating pump that pumps a finite amount of lubricant during a single pumping stroke and a stepper motor for operating the pump through incremental phases of movement each less than a stroke. The lubricant requirements of the machine are determined and the driving increments are adjusted so as to provide a pumping stroke when the lubricant consumption of the machine reaches the output of the pump. Various arrangements of stepper motors and control arrangements are disclosed for controlling the amount and timing of the lubricate delivery.
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: January 28, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventors: Takao Moriya, Masaya Suenari
  • Patent number: 5595156
    Abstract: A number of embodiments of multiple intake valve internal combustion engines that permit the generation of tumble in one direction and at a high velocity under one engine running condition and counter tumble at a lower velocity but in a higher flow volume under other running conditions. The system includes an arrangement for disabling the operation of at least one of the intake passages and for redirecting the flow through another of the intake passages. Embodiments having two, three, and four intake valves per cylinder are disclosed.
    Type: Grant
    Filed: July 19, 1995
    Date of Patent: January 21, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Hiroyuki Tsuzuku
  • Patent number: 5593007
    Abstract: A number of embodiments of tubular type shock absorbers that permit improved damping characteristics in both directions by providing a third fluid chamber that surrounds the central shock absorber portion which defines the normal first and second fluid chambers separated by a piston connected by a piston rod to one of the two suspended elements. An annular piston is connected to the piston rod and displaces fluid from the third fluid chamber through a shock absorbing arrangement for augmenting the shock absorbing action of the centrally positioned shock absorber. Several embodiments of reservoir arrangements are disclosed.
    Type: Grant
    Filed: December 1, 1993
    Date of Patent: January 14, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Pekka Siltanen
  • Patent number: 5593330
    Abstract: A number of embodiments of personal watercraft having safety switches for enabling a kill switch if the operator falls overboard. In addition, a key-operated waterproof main switch is provided in the circuit to facilitate locking and to avoid drainage of the battery when not in use. A number of mounting arrangements for assuring further watertightness are also disclosed.
    Type: Grant
    Filed: December 1, 1994
    Date of Patent: January 14, 1997
    Assignee: Yamaha Hatsudoki Kabushiki Kaisha
    Inventor: Noboru Kobayashi