Patents by Inventor Ryuichi Yamashita
Ryuichi Yamashita 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).
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Publication number: 20240168496Abstract: A server device includes an area setting unit that sets a first area in which a first lawnmower executes first lawn-mowing work in a work area and a second area in which a second lawnmower second lawn-mowing work in the work area, a zone dividing unit that divides the work area into plural virtual zones, a time range setting unit that sets a first time range in which the first lawnmower executes the first lawn-mowing work in each of the virtual zones included in the plural virtual zones and a second time range in which the second lawnmower executes the second lawn-mowing work in each of the virtual zones included in the plural virtual zones, and a notification unit that notifies the first time range and the second time range to a smartphone. Consequently, a user can check a possibilty of contact between the first and second lawnmowers.Type: ApplicationFiled: March 12, 2021Publication date: May 23, 2024Inventors: Akifumi Yamashita, Ryota Hisada, Takuya Kanisawa, Ryuichi Kimata
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Patent number: 6678224Abstract: A tracking error balance adjustment circuit, and a current control circuit used for a variable gain RF amplifier automatically controlled to output a signal having a predetermined amplitude. The tracking error balance adjustment circuit comprises two separate gain adjusting circuits, each having variable attenuation circuit having first gm amplifier of variable gm type, a second gm amplifier of variable gm type connected to the variable attenuation circuit, and an output circuit connected to the second gm amplifier, comprising an operational amplifier circuit having feedback resistor, wherein the first and second gm amplifiers are differentially controlled commonly by a control current.Type: GrantFiled: November 25, 2002Date of Patent: January 13, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Ryuichi Yamashita, Hiroyuki Haga, Shinobu Murai
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Publication number: 20030072227Abstract: A tracking error balance adjustment circuit, and a current control circuit used for a variable gain RF amplifier automatically controlled to output a signal having a predetermined amplitude. The tracking error balance adjustment circuit comprises two separate gain adjusting circuits, each having variable attenuation circuit having first gm amplifier of variable gm type, a second gm amplifier of variable gm type connected to the variable attenuation circuit, and an output circuit connected to the second gm amplifier, comprising an operational amplifier circuit having feedback resistor, wherein the first and second gm amplifiers are differentially controlled commonly by a control current.Type: ApplicationFiled: November 25, 2002Publication date: April 17, 2003Inventors: Ryuichi Yamashita, Hiroyuki Haga, Shinobu Murai
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Patent number: 6504799Abstract: A tracking error balance adjustment circuit, and a current control circuit used for a variable gain RF amplifier automatically controlled to output a signal having a predetermined amplitude. The tracking error balance adjustment circuit comprises two separate gain adjusting circuits, each having variable attenuation circuit having first gm amplifier of variable gm type, a second gm amplifier of variable gm type connected to the variable attenuation circuit, and an output circuit connected to the second gm amplifier, comprising an operational amplifier circuit having feedback resistor, wherein the first and second gm amplifiers are differentially controlled commonly by a control current.Type: GrantFiled: March 10, 2000Date of Patent: January 7, 2003Assignee: Kabushiki Kaisha ToshibaInventors: Ryuichi Yamashita, Hiroyuki Haga, Shinobu Murai
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Patent number: 4323045Abstract: Several embodiments of exhaust gas recirculation systems for internal combustion engines. In each embodiment an arrangement is provided for cooling at least a portion of the recirculated exhaust gases during at least some running conditions prior to reintroduction into the combustion chamber. In one embodiment, the cooled exhaust gases are mixed with uncooled exhaust gases to provide the desired temperature of exhaust gas recirculation. In another embodiment, the exhaust gases are cooled by a fan that is operated in response to the engine running condition. In addition, a device is incorporated for controlling the cooling of the exhaust gases in response to engine temperature.Type: GrantFiled: November 30, 1979Date of Patent: April 6, 1982Assignee: Yamaha Hatsudoki Kabushiki KaishaInventor: Ryuichi Yamashita
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Patent number: 4214561Abstract: An induction system for an internal combustion engine that is provided with a relatively small auxiliary intake passage that delivers the intake charge to the combustion chamber at a high velocity and high degree of turbulence. Throttle valve means are provided for directing a substantial portion of the idle and low-speed intake into the chamber through this auxiliary intake passage so as to improve flame propagation and engine performance under these running conditions. The intake for the auxiliary induction passage is disposed so that it will be exposed to atmospheric pressure under at least some low-speed running characteristics so as to improve the amount of charge drawn through the auxiliary induction passage during these conditions.Type: GrantFiled: June 1, 1978Date of Patent: July 29, 1980Assignee: Yamaha Hatsukoki Kabushiki KaishaInventors: Hiromitsu Matsumoto, Ryuichi Yamashita
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Patent number: 4195602Abstract: In an internal combustion engine intended to be run on a leaner-than-stoichiometric mixture, intake control means which when "enabled" permit introduction of supplementary air under deceleration conditions to prevent over-enriching which would otherwise occur when the fuel film on the induction system wall abruptly evaporates. At various temperatures, the feature is disabled completely or for short periods of time so as not to cause over-leaning of the mixture at excessively cold temperatures, or at start up at cold or merely warm conditions.Type: GrantFiled: March 6, 1978Date of Patent: April 1, 1980Assignee: Yamaha Hatsudoki Kabushiki KaishaInventors: Ryuichi Yamashita, Hiromitsu Matsumoto
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Patent number: 4192140Abstract: Apparatus and method for the protection of an exhaust gas reactor, for example a catalytic element or a thermal reactor, disposed in the exhaust conduit of an internal combustion engine which is operated on a lean air/fuel mixture. This invention provides means for protection of the exhaust gas reactor from excessive temperatures under deceleration conditions by regulating the air/fuel mixture ratio in the induction means of the engine whereby to restrict the oxidation which occurs at the reactor. One method according to the invention comprises adding supplementary air to the induction means for a limited time after the throttle is closed under deceleration conditions, and after an initial delay, adding supplementary fuel to the induction means while the engine continues to operate under deceleration conditions.Type: GrantFiled: September 3, 1974Date of Patent: March 11, 1980Assignee: Yamaha Hatsudoki Kabushiki KaishaInventors: Ryuichi Yamashita, Hiromitsu Matsumoto
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Patent number: 4191716Abstract: A carburetor for internal combustion engines including an intake passage leading to a combustion chamber of the engine, a main fuel nozzle opening to the intake passage, a main throttle valve device provided in said intake passage, a float chamber for supplying fuel to said main fuel nozzle, a starting air passage opening to the intake passage at the downstream side of the throttle valve shut-off valve in the starting air passage, a second float chamber for supplying fuel to said starting air passage, and a passage introducing intake suction pressure to the upper portion of only the second float chamber. Also disclosed is apparatus wherein the main fuel nozzle and starting fuel nozzle communicate with a common float chamber, and the starter valve means comprises means for connecting the overlaying region of said float chamber with the intake passage downstream of the throttle valve when the starter valve means is in the open position.Type: GrantFiled: December 18, 1978Date of Patent: March 4, 1980Assignee: Yamaha Hatsudoki Kabushiki KaishaInventors: Ryuichi Yamashita, Hiromitsu Matsumoto
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Patent number: 4144861Abstract: Internal combustion engine including a fuel supply system which comprises a main carburetor having an intake passage leading to a combustion chamber of the engine. The engine is further provided with a starting fuel supply device which includes a starting fuel supply passage having one end opening to atmosphere and the other end connected with the intake passage. The starting fuel supply passage is provided with a fuel discharge nozzle and a starter valve disposed downstream of the nozzle. The supply passage has a cross-sectional area which is small in relation to that of the intake passage so that adequate air flow speed can be ensured even in engine starting period.Type: GrantFiled: May 12, 1976Date of Patent: March 20, 1979Assignee: Yamaha Hatsudoki Kabushiki KaishaInventors: Ryuichi Yamashita, Hiromitsu Matsumoto, Masato Eda
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Patent number: 4117813Abstract: An internal combustion engine and means to operate the same to produce minimal quantities and concentrations of oxides of nitrogen (NOx), carbon monoxide (CO) and unburned hydrocarbons (HC). The engine is operated with a lean air/fuel mixture at both low and high load conditions, thereby minimizing said emissions. Low load operation on lean mixtures is made possible by means and methods for maintaining at a suitably low numerical value the residual fraction which is defined as the ratio of gases in a cylinder from a previous cycle and the total gases in the cylinder for the next cycle (said gases from a previous cycle plus new mixture). Said means may comprise apparatus to shorten the duration of intake and exhaust valve overlap, or of opening the engine throttle wider than normal and retarding the ignition to reduce the engine speed at low loads. Means is preferably provided wherein the fuel in the air/fuel mixture is well-vaporized and the mixture is uniform and homogeneous.Type: GrantFiled: October 28, 1976Date of Patent: October 3, 1978Assignee: Yamaha Hatsudoki Kabushiki KaishaInventors: Ryuichi Yamashita, Hiromitsu Matsumoto
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Patent number: 4106464Abstract: A system and method for controlling a lean-burning internal combustion engine. The system and method enable a starter carburetor to operate at cold but not at hot temperature, to provide gulp air and counterbalance means for the starter carburetor, together with means to inhibit them at startup and for a brief time thereafter, and to inhibit exhaust gas recirculation when it would be deleterious to smooth operation. The system also provides for continuous accelerator pump operation during acceleration except at high temperatures. The objective is to secure smooth operation at startup, cold, warm or hot, and during transient conditions during engine warmup.Type: GrantFiled: August 24, 1976Date of Patent: August 15, 1978Assignee: Yamaha Hatsudoki Kabushiki KaishaInventors: Ryuichi Yamashita, Hiromitsu Matsumoto, Masato Eda