Patents by Inventor Robert K. Havemann

Robert K. Havemann 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: 5074329
    Abstract: A three-way valve for a refrigeration system having a body portion which includes an intermediate member and first and second end bells. The body portion includes an inlet adapted for connection to a refrigerant compressor, first and second major outlets respectively adapted for connection to a condenser and an evaporator, and a minor outlet adapted for selective connection to the low side of the compressor. The body portion defines a cavity within which a removable cartridge is disposed which contains all movable parts of the valve, as well as all parts subject to wear. The cartridge is freely removable for maintenance purposes after removal of a predetermined one of the end bells. An equalizing check valve is carried by the cartridge which limits back pressure build up via the first major outlet when the valve is positioned to connect the inlet to the second major outlet.
    Type: Grant
    Filed: November 13, 1990
    Date of Patent: December 24, 1991
    Assignee: Thermo King Corporation
    Inventors: Robert K. Havemann, Darrel J. Hokanson, William B. McKenzie
  • Patent number: 5046326
    Abstract: A transport refrigeration system having an evaporator, an evaporator blower, a variable speed drive for the evaporator blower, a refrigerant compressor, and a prime mover for the compressor which includes an internal combustion engine having an output shaft, a pressurized oil lubrication system and an oil sump. The variable speed drive includes a fluid coupling which utilizes oil provided by the lubrication system of the internal combustion engine.
    Type: Grant
    Filed: October 24, 1990
    Date of Patent: September 10, 1991
    Assignee: Thermo King Corporation
    Inventors: Robert K. Havemann, Loyal V. Pittman
  • Patent number: 4960088
    Abstract: A low fuel shut-off system for a Diesel engine which includes a fuel supply circuit comprising a main fuel tank, a transfer pump, a filter array, an injection pump, injection nozzles, and an auxiliary fuel tank in the fuel circuit between the transfer pump and the injection pump. A level sensor in the auxiliary fuel tank provides a signal when the fuel level drops below a predetermined point, with the signal being used by associated electrical control to shut down the engine while a supply of fuel still remains in the fuel supply circuit between the auxiliary tank and the injection pump, and in the auxiliary tank, which is sufficient to start the engine without priming.
    Type: Grant
    Filed: September 8, 1989
    Date of Patent: October 2, 1990
    Assignee: Thermo King Corporation
    Inventors: Robert K. Havemann, Herman H. Viegas, Ricardo S. DeGrego
  • Patent number: 4932841
    Abstract: A combination oil pressure regulator and low oil pressure indicator for regulating the maximum oil pump pressure of a refrigerant compressor, and for providing a signal or indication when the oil pressure falls below a predetermined minimum value. The position of a piston in a housing is controlled by opposing forces provided by the oil pressure to be monitored and by a compression spring. When the oil pressure reaches a predetermined maximum value, relief apertures in the piston and housing establish a pressure relief path to the compressor crank case. When the oil pressure drops below a predetermined minimum value, the piston contacts and electrically grounds an electrically conductive element, providing a signal for associated control.
    Type: Grant
    Filed: March 20, 1989
    Date of Patent: June 12, 1990
    Assignee: Thermo King Corporation
    Inventor: Robert K. Havemann
  • Patent number: 4890459
    Abstract: A monitor for detecting air leaks during the operation of a closed vapor compression refrigeration system having a refrigerant compressor driven by a prime mover. An oxygen sensor is disposed in the discharge manifold of the compressor, and the electrical output of the sensor is compared with a reference voltage by a comparator. When an air leak is detected by the comparator, refrigerant control responsive to such detection provides an alarm and/or shuts down the refrigeration system.
    Type: Grant
    Filed: December 8, 1988
    Date of Patent: January 2, 1990
    Assignee: Thermo King Corporation
    Inventor: Robert K. Havemann
  • Patent number: 4770002
    Abstract: A transport refrigeration system including a compressor, a prime mover for the compressor, a condenser, and an evaporator blower assembly. The evaporator blower assembly includes a shaft driven by the prime mover, a first blower fixed to the driven shaft, a second blower journaled for rotation about the driven shaft, and a clutch for coupling and decoupling the first and second blowers. The volume of air moved through the evaporator and into the conditioned space or cargo area is thus selectable based upon need of the transport refrigeration system, without the necessity of changing the speed of the prime mover. The resulting savings in power realized when only one blower is being driven is automatically translated into fuel savings and/or increased cooling capacity.
    Type: Grant
    Filed: September 8, 1987
    Date of Patent: September 13, 1988
    Assignee: Thermo King Corporation
    Inventors: Herman H. Viegas, Robert K. Havemann, Bruce E. McClellan
  • Patent number: 4616743
    Abstract: A clutch is provided in which the friction shoes 40a, b and c are attached to a hub 38 through leaf springs 48a, 48b, 48c with the leading end of the leaf springs, relative to hub rotation, being connected to the leading end portions of the hub surfaces 38a, b and c, and the trailing end portions of the springs being connected to the trailing end portions of the shoes, the originally flat leaf springs assuming a shallow S-shape by being connected to the parts, this S-shape of the springs absorbing torque peaks from the internal combustion engine driving the clutch.
    Type: Grant
    Filed: January 11, 1985
    Date of Patent: October 14, 1986
    Assignee: Thermo King Corporation
    Inventor: Robert K. Havemann
  • Patent number: 4329957
    Abstract: An engine speed and loss of oil pressure control arrangement for an engine such as is used in transport refrigeration and is operative at a low speed and a high speed, the arrangement including two axially aligned pistons 12 and 36 into adjacent cylinders 10 and 34, respectively, the first piston 12 moving from an engine off position to a low speed position upon closure of the valve 22 when engine operation is initiated, this forcing the second piston 36 to a low speed position which effects said low speed through leakage 40 to the engine speed control means, the second piston 36 moving further to the right to an engine high speed position upon opening of valve 28 in a conduit leading from the first cylinder to the second cylinder.
    Type: Grant
    Filed: October 15, 1980
    Date of Patent: May 18, 1982
    Assignee: Thermo King Corporation
    Inventor: Robert K. Havemann