Patents by Inventor Christian Helmut Thoma

Christian Helmut Thoma 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: 7318553
    Abstract: An apparatus for heating a liquid includes a housing having an internal chamber and a rotor disposed in the chamber. The rotor is preferably cylindrical and operates inside a bore provided by the housing without touching, the shape of the bore preferably being parallel with the exterior surface of the rotor, and a series of openings disposed over the rotor surface. At least one internal passageway in the rotor and elements for: pre-heating some or all the incoming fluid in the chamber; priming the chamber initially; cooling certain temperature sensitive components; injecting fluid into a partially evacuated volume; developing a vacuum state during operation expeditiously.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: January 15, 2008
    Inventor: Christian Helmut Thoma
  • Patent number: 7089886
    Abstract: An apparatus for heating a liquid comprising a housing having an internal chamber and a rotor disposed in said chamber. A drive shaft rotatably supported in the housing and extending into said chamber for imparting mechanical energy to the rotor. The rotor having a generally hemi-spherically shaped form and provided with a series of openings. A fluid intake passage in said housing preferably arranged to be nearer the rotational axis of the rotor and a fluid exit passage preferably positioned radially outwardly of said rotor.
    Type: Grant
    Filed: April 1, 2004
    Date of Patent: August 15, 2006
    Inventor: Christian Helmut Thoma
  • Patent number: 6976486
    Abstract: An apparatus for heating a liquid comprising a housing having an internal chamber and a rotor disposed in said chamber. A drive shaft rotatably supported in the housing and extending into said chamber for imparting mechanical energy to the rotor. The rotor being provided with a series of openings generally arranged to be parallel to the rotational axis of the drive shaft. The rotor in the form of a disc and the housing formed with radial surfaces on either side of said rotor disc. The rotor may comprise a single disc or alternatively, a series of dics in a liminated formation. A fluid intake passage in said housing preferably arranged adjacent the center of the disc and a fluid exit passage, generally arranged to be circumeferntially outwards of said disc.
    Type: Grant
    Filed: October 10, 2003
    Date of Patent: December 20, 2005
    Inventor: Christian Helmut Thoma
  • Patent number: 6959669
    Abstract: The apparatus has a housing with a main chamber in which a rotor is situated. A drive shaft drives the rotor about a longitudinal axis of rotation. The housing has a fluid inlet and a fluid outlet, the fluid inlet communicating with an inlet region and a fluid outlet communicating with an exit region. The outer surface of the rotor forms one boundary for the fluid heat generating region and is confronted by the inner surface of the main chamber which is the other boundary. At least one of these surfaces is angularly inclined relative to the axis of rotation of the drive shaft and rotor. By bodily shifting the rotor in a direction along the longitudinal axis, an increase or decrease in the distance between the outer and inner surfaces is possible in order to adjust for wear or to change the degree of shear experienced by the passing fluid.
    Type: Grant
    Filed: December 3, 2003
    Date of Patent: November 1, 2005
    Inventor: Christian Helmut Thoma
  • Patent number: 6884195
    Abstract: A hydrostatic transaxle axle assembly for a vehicle such as a grass mowing lawn or garden tractor comprising a housing for an internally disposed hydrostatic transmission having a variable-displacement hydraulic pump fluidly connected to a fixed-displacement hydraulic motor, the hydraulic motor being connected by differential gearing to axle shafts supported in the housing. The housing is formed by three housing members, two of which are preferably separable on a parting plane coincident with the longitudinal axes of the axle shafts. One of the housing members being provided with an opening to allow a portion of one of the other housing members to extend through, and where the extending housing member contains within its interior a number of internal fluid passages for fluidly connecting the hydraulic pump to the hydraulic motor.
    Type: Grant
    Filed: June 18, 2003
    Date of Patent: April 26, 2005
    Assignee: Hydro-Thoma Limited
    Inventors: Christian Helmut Thoma, George Duncan McRae Arnold
  • Patent number: 6875147
    Abstract: An axle assembly has an internally disposed hydrostatic transmission and speed reducing gearing. An input shaft supported in the housing drives a variable-displacement hydraulic pump, the pump fluidly coupled to a fixed-displacement hydraulic motor, and the motor drivingly connected through the speed reducing gearing to an output axle shaft. The housing being formed by three housing members and joined together along a substantially planar and horizontally peripheral seam formed therebetween such that two of the housing members are to one side of the seam and join with the third housing element. Two internal chambers formed by the three housing elements where one chamber contains the hydrostatic transmission and the other chamber contains the speed reducing gearing. A connecting shaft spanning between the chambers to provide the power transmission link between the hydrostatic transmission and the speed reducing gearing.
    Type: Grant
    Filed: June 6, 2003
    Date of Patent: April 5, 2005
    Assignee: Hydro-Thoma Limited
    Inventors: Christian Helmut Thoma, George Duncan McRae Arnold
  • Patent number: 6823820
    Abstract: The apparatus has a housing with a main chamber in which a rotor is situated. The drive shaft drives the rotor about a longitudinal axis of rotation. The housing has a fluid inlet and a fluid outlet, the fluid inlet communicating with an inlet region and a fluid outlet communicating with an exit region. The outer surface of the rotor forms one boundary for the fluid heat generating region chamber which is confronted by the inner surface of the main chamber which is the other boundary. At least one of these surfaces is angularly inclined relative to the axis of rotation of the drive shaft and rotor. By bodily shifting the rotor in a direction along the longitudinal axis, an increase or decrease in the distance between the outer and inner surfaces is possible in order to adjust for wear or to change the degree of shear experienced by the passing fluid.
    Type: Grant
    Filed: December 3, 2002
    Date of Patent: November 30, 2004
    Inventor: Christian Helmut Thoma
  • Publication number: 20040213668
    Abstract: An apparatus for heating a liquid comprising a housing having an internal chamber and a rotor disposed in said chamber. A drive shaft rotatably supported in the housing and extending into said chamber for imparting mechanical energy to the rotor. The rotor having a generally hemi-spherically shaped form and provided with a series of openings. A fluid intake passage in said housing preferably arranged to be nearer the rotational axis of the rotor and a fluid exit passage preferably positioned radially outwardly of said rotor.
    Type: Application
    Filed: April 1, 2004
    Publication date: October 28, 2004
    Inventor: Christian Helmut Thoma
  • Publication number: 20040194775
    Abstract: An apparatus for heating a liquid comprising a housing having an internal chamber and a rotor disposed in said chamber. A drive shaft rotatably supported in the housing and extending into said chamber for imparting mechanical energy to the rotor. The rotor being provided with a series of openings generally arranged to be parallel to the rotational axis of the drive shaft. The rotor in the form of a disc and the housing formed with radial surfaces on either side of said rotor disc. The rotor may comprise a single disc or alternatively, a series of dics in a liminated formation. A fluid intake passage in said housing preferably arranged adjacent the center of the disc and a fluid exit passage, generally arranged to be circumeferntially outwards of said disc.
    Type: Application
    Filed: October 10, 2003
    Publication date: October 7, 2004
    Inventor: Christian Helmut Thoma
  • Patent number: 6796121
    Abstract: A hydrostatic transaxle axle assembly for a vehicle has the housing formed by three housing members, two of which are preferably separable on a parting plane coincident with the longitudinal axes of the axle shafts. One of the housing members is provided with an opening to allow a portion of one of the other housing members to extend through, and the extending housing member contains within its interior a number of internal fluid passages for fluidly connecting the hydraulic pump to the hydraulic motor.
    Type: Grant
    Filed: July 25, 2002
    Date of Patent: September 28, 2004
    Assignee: Hydro-Thoma Limited
    Inventors: Christian Helmut Thoma, George Duncan McRae Arnold
  • Patent number: 6782699
    Abstract: A hydrostatic transaxle axle assembly for a vehicle has the housing is formed by three housing members, two of which are preferably separable on a parting plane coincident with the longitudinal axes of the axle shafts. One of the housing members being provided with an opening to allow a portion of one of the other housing members to extend through, and where the extending housing member contains within its interior a number of internal fluid passages for fluidly connecting the hydraulic pump to the hydraulic motor.
    Type: Grant
    Filed: April 30, 2002
    Date of Patent: August 31, 2004
    Assignee: Hydro-Thoma Limited
    Inventors: Christian Helmut Thoma, George Duncan McRae Arnold
  • Patent number: 6779421
    Abstract: A hydrostatic transmission and gear transmission located in the same or separate housings structures, and mechanically drivingly connected together by a power transmission shaft. That housing structure surrounding the hydrostatic transmission defining a first internal volume containing the hydrostatic transmission components and providing a receptacle for the hydrostatic fluid. That housing structure surrounding the gear transmission defining a gear compartment sump. As one example, the housing structure surrounding the hydrostatic transmission may further define a second internal volume to operate as an overflow receiver for fluid transferred from the first internal volume. A duct operating in accordance with the siphon principle connects the internal volumes and where a pressure restriction valves ensures an above ambient pressure level in the volumes when the hydrostatic and gear transmission is operating. Alternatively, the gear compartment sump may act as the second internal volume.
    Type: Grant
    Filed: May 29, 2003
    Date of Patent: August 24, 2004
    Assignee: Hydro-Thoma Limited
    Inventors: George Duncan McRae Arnold, Christian Helmut Thoma
  • Publication number: 20040103856
    Abstract: The apparatus has a housing with a main chamber in which a rotor is situated. A drive shaft drives the rotor about a longitudinal axis of rotation. The housing has a fluid inlet and a fluid outlet, the fluid inlet communicating with an inlet region and a fluid outlet communicating with an exit region. The outer surface of the rotor forms one boundary for the fluid heat generating region and is confronted by the inner surface of the main chamber which is the other boundary. At least one of these surfaces is angularly inclined relative to the axis of rotation of the drive shaft and rotor. By bodily shifting the rotor in a direction along the longitudinal axis, an increase or decrease in the distance between the outer and inner surfaces is possible in order to adjust for wear or to change the degree of shear experienced by the passing fluid.
    Type: Application
    Filed: December 3, 2003
    Publication date: June 3, 2004
    Inventor: Christian Helmut Thoma
  • Publication number: 20040103855
    Abstract: The apparatus has a housing with a main chamber in which a rotor is situated. A drive shaft drives the rotor about a longitudinal axis of rotation. The housing has a fluid inlet and a fluid outlet, the fluid inlet communicating with an inlet region and a fluid outlet communicating with an exit region. The outer surface of the rotor forms one boundary for the fluid heat generating region and is confronted by the inner surface of the main chamber which is the other boundary. At least one of these surfaces is angularly inclined relative to the axis of rotation of the drive shaft and rotor. By bodily shifting the rotor in a direction along the longitudinal axis, an increase or decrease in the distance between the outer and inner surfaces is possible in order to adjust for wear or to change the degree of shear experienced by the passing fluid.
    Type: Application
    Filed: December 3, 2002
    Publication date: June 3, 2004
    Inventor: Christian Helmut Thoma
  • Publication number: 20030216208
    Abstract: A hydrostatic transaxle axle assembly for a vehicle such as a grass mowing lawn or garden tractor comprising a housing for an internally disposed hydrostatic transmission having a variable-displacement hydraulic pump fluidly connected to a fixed-displacement hydraulic motor, the hydraulic motor being connected by differential gearing to axle shafts supported in the housing. The housing is formed by three housing members, two of which are preferably separable on a parting plane coincident with the longitudinal axes of the axle shafts. One of the housing members being provided with an opening to allow a portion of one of the other housing members to extend through, and where the extending housing member contains within its interior a number of internal fluid passages for fluidly connecting the hydraulic pump to the hydraulic motor.
    Type: Application
    Filed: June 18, 2003
    Publication date: November 20, 2003
    Applicant: HYDRO-THOMA LIMITED
    Inventors: Christian Helmut Thoma, George Duncan McRae Arnold
  • Publication number: 20030199354
    Abstract: An axle assembly for use in lawn tractors, pedestrian walk-behind mowers and snow blowers in the form of a housing having an internally disposed hydrostatic transmission and speed reducing gearing. An input shaft supported in the housing for driving a variable-displacement hydraulic pump of the hydrostatic transmission, the pump fluidly coupled to a fixed-displacement hydraulic motor of the hydrostatic transmission, and where the motor is drivingly connected through the speed reducing gearing to an output axle shaft or shafts. A mechanical differential disposed within said housing for applications requiring differential speeds of said axle output shafts. The housing being formed by three housing members and joined together along a substantially planar and horizontally peripheral seam formed therebetween such that two of said housing members are to one side of said seam and join with the third housing element.
    Type: Application
    Filed: June 6, 2003
    Publication date: October 23, 2003
    Applicant: HYDRO-THOMA LIMITED
    Inventors: Christian Helmut Thoma, George Duncan McRae Arnold
  • Publication number: 20030192402
    Abstract: A hydrostatic transmission and gear transmission located in the same or separate housings structures, and mechanically drivingly connected together by a power transmission shaft. That housing structure surrounding the hydrostatic transmission defining a first internal volume containing the hydrostatic transmission components and providing a receptacle for the hydrostatic fluid. That housing structure surrounding the gear transmission defining a gear compartment sump. As one example, the housing structure surrounding the hydrostatic transmission may further define a second internal volume to operate as an overflow receiver for fluid transferred from the first internal volume. A duct operating in accordance with the siphon principle connects the internal volumes and where a pressure restriction valves ensures an above ambient pressure level in the volumes when the hydrostatic and gear transmission is operating. Alternatively, the gear compartment sump may act as the second internal volume.
    Type: Application
    Filed: May 29, 2003
    Publication date: October 16, 2003
    Applicant: HYDRO-THOMA LIMITED
    Inventors: George Duncan McRae Arnold, Christian Helmut Thoma
  • Patent number: 6626065
    Abstract: A hydrostatic transmission and gear transmission located in the same or separate housings structures, and mechanically drivingly connected together by a power transmission shaft. That housing structure surrounding the hydrostatic transmission defining a first internal volume containing the hydrostatic transmission components and providing a receptacle for the hydrostatic fluid. That housing structure surrounding the gear transmission defining a gear compartment sump. As one example, the housing structure surrounding the hydrostatic transmission may further define a second internal volume to operate as an overflow receiver for fluid transferred from the first internal volume. A duct operating in accordance with the siphon principle connects the internal volumes and where a pressure restriction valves ensures an above ambient pressure level in the volumes when the hydrostatic and gear transmission is operating. Alternatively, the gear compartment sump may act as the second internal volume.
    Type: Grant
    Filed: May 15, 2001
    Date of Patent: September 30, 2003
    Assignee: Hydro-Thoma Limited
    Inventors: George Duncan McRae Arnold, Christian Helmut Thoma
  • Patent number: 6607462
    Abstract: An axle assembly for use in lawn tractors, pedestrian walk-behind mowers and snow blowers in the form of a housing having an internally disposed hydrostatic transmission and speed reducing gearing. An input shaft supported in the housing for driving a variable-displacement hydraulic pump of the hydrostatic transmission, the pump fluidly coupled to a fixed-displacement hydraulic motor of the hydrostatic transmission, and where the motor is drivingly connected through the speed reducing gearing to an output axle shaft or shafts. A mechanical differential disposed within said housing for applications requiring differential speeds of said axle output shafts. The housing being formed by three housing members and joined together along a substantially planar and horizontally peripheral seam formed therebetween such that two of said housing members are to one side of said seam and join with the third housing element.
    Type: Grant
    Filed: February 11, 2002
    Date of Patent: August 19, 2003
    Assignee: Hydro-Thoma Limited
    Inventors: Christian Helmut Thoma, George Duncan McRae Arnold
  • Patent number: 6595887
    Abstract: A hydrostatic power transmitting device in combination with a speed reducing apparatus together disposed within a common housing having an interior space divided by partitioning device into a first region in which the hydrostatic unit is disposed and a second region in which said speed reducer is accommodated. First and second regions are segregated from each other by the partitioning device being in the form of a flexible non-porous barrier. The elastically deformable partitioning device can therefore adjust its shape to take up any change in the amount of hydrostatic transmitting fluid in the first region due to temperature changes of the fluid and facilitates the regulation in depth of lubricant held by the second region. Thereby an initially low level of lubricant in the second region lessens the adverse effect of power-retarding drag losses, especially during cold weather winter operation, and a rising level of lubricant ensures good lubrication when temperatures are elevated and viscosity is low.
    Type: Grant
    Filed: February 26, 2002
    Date of Patent: July 22, 2003
    Assignee: Hydro-Thoma Limited
    Inventor: Christian Helmut Thoma