Patents by Inventor Hiroaki Hama

Hiroaki Hama 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: 5323618
    Abstract: A heat storage type air conditioning system capable of performing refrigerant receiving and discharging control and oil quantity control, which, in operating the general cooling circuit and the cold radiating circuit simultaneously or separately, is free from difficulties that the compressor is damaged or the cooling capacity is lowered when the quantities of refrigerant in those circuits are excessively increased or decreased, and is able to continue the operations with the quantity of refrigerant and the quantity of ice machine oil adjusted to suitable values. In the heat storage type air conditioning system, evaporators are provided in a general cooling circuit driven by a compressor and in a cold radiating circuit driven by a refrigerant gas pump, respectively, so that those circuits operate independently of each other. Furthermore, bypass circuits are provided to allow refrigerant to flow between liquid pipes and between gas pipes in those circuits.
    Type: Grant
    Filed: February 17, 1993
    Date of Patent: June 28, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Yoshida, Hideaki Tagashira, Masami Imanishi, Hiroaki Hama, Moriya Miyamoto, Hiroshi Nakata, Osamu Morimoto
  • Patent number: 4765149
    Abstract: A refrigeration cycle apparatus comprises first and second compressors, a four-way valve, an outdoor heat exchanger, first and second expansion means, at least one indoor heat exchanger, an accumulator, a refrigerant circuit connecting these element in order, a reservoir connected to the accumulator through an overflow pipe and a refrigerant supplying pipe with a first solenoid valve and a feeding pipe with a second solenoid valve for connecting the inlet side of the expansion means to the reservoir, wherein the first and second solenoid valves are opened and closed depending on operational conditions in a refrigeration cycle.
    Type: Grant
    Filed: July 30, 1987
    Date of Patent: August 23, 1988
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takashi Shiga, Hidekazu Tani, Hiroaki Hama, Hitoshi Iijima
  • Patent number: 4672822
    Abstract: The refrigerating cycle apparatus of the invention is provided with a pair of condenser and evaporator, two compressors, and a riser piping for rising therethrough a refrigerant and provided at a suction pipe for one compressor, the suction pipe for the other compressor being connected with the riser piping, so that even when the flood back condition occurs during the individual operation of the one compressor, both compressors are adapted to maintain a proper oil quantity therein.
    Type: Grant
    Filed: December 17, 1985
    Date of Patent: June 16, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hitoshi Iijima, Hiroaki Hama
  • Patent number: 4563879
    Abstract: A heat pump employing a capillary tube as an expansion device is disclosed. The main throttle portion of the heat pump comprises a main capillary tube and a by-pass through which a portion of the refrigerant flows and cools the refrigerant flowing through the main capillary tube. A solenoid valve for controlling the flow of refrigerant through the main capillary tube is connected to the intake of the main capillary tube, and an electrical expansion valve is connected to the intake of the by-pass for controlling the flow therethrough. An auxiliary capillary tube for cooling and an auxiliary capillary tube for heating are connected in parallel with the main throttle portion, both capillary tubes having a higher resistance to flow than the main capillary tube.
    Type: Grant
    Filed: May 21, 1985
    Date of Patent: January 14, 1986
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroaki Hama, Masami Imanishi, Naoki Tanaka
  • Patent number: 4507938
    Abstract: An air-conditioning and hot water supply system, which comprises a heat pump type refrigerating device at the primary side having a user side heat-exchanger and a heat source side heat-exchanger with a coolant of excellent low temperature characteristic being filled in both of them; a refrigerating device at the secondary side having a user side condenser for heating water for hot water supply and a heat source side evaporator with a coolant of excellent high temperature characteristic being filled in both of them; fan coil units for air-conditioning communicatively connected with the user side heat-exchanger of the heat pump type refrigerating device at the primary side and the heat source side evaporator of the refrigerating device at the secondary side; and a circuit for air-conditioning, through which cold or warm water is caused to circulate between the user side heat exchanger and the heat source side evaporator, the cold water or warm water after the air-conditioning operation by the fan coil units bei
    Type: Grant
    Filed: September 8, 1983
    Date of Patent: April 2, 1985
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroaki Hama, Toshiro Abe
  • Patent number: 4448037
    Abstract: Described is a cooling/heating and hot water service system making use of a single heat source apparatus. The system includes a heat pump chiller designed to perform cyclic operations of heating and cooling, a heat exchanger unit having a heat exchanger adapted for supplying hot water and a water reservoir. The operating time zone for storage of hot water and the operating time zone for heating and cooling the room are set by a first program timer while the operating time zone for servicing hot water is set by a second program timer.
    Type: Grant
    Filed: January 19, 1983
    Date of Patent: May 15, 1984
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroaki Hama, Masami Imanishi, Yasuyuki Funahashi, Seiichi Kato