Patents Assigned to Danfoss A/S
  • Patent number: 5214930
    Abstract: Method and apparatus for controlling a prior art refrigeration system of the type having an evaporator, a variable capacity compressor arrangement, and switching apparatus between a control unit and the compressor arrangement. The compressor arrangement thereof has adding and subtracting inputs which translate input signals to respectively increase or decrease step by step the effective capacity of the compressor arrangement. The switching apparatus thereof has adding and subtracting inputs and outputs and a reset output which is made effective after each increase or decrease of the effective capacity of the compressor arrangement. The method and apparatus herein involves processing a data signal which is indicative of the temperature status of the evaporator.
    Type: Grant
    Filed: May 4, 1992
    Date of Patent: June 1, 1993
    Assignee: Danfoss A/S
    Inventor: Christian Bendtsen
  • Patent number: 5204566
    Abstract: The apparatus includes a laminated core that has frontal end faces and slots with a winding extending in the slots. An electrical insulating end plate is provided adjacent at each frontal end face and adjacent to the winding heads of the winding. At least one of the end plates has a connecting box with a plurality of clamps for the ends of the windings and the terminal of a motor protection device.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: April 20, 1993
    Assignee: Danfoss A/S
    Inventors: Sverre Martin Borgen, Poul Petersen, Heinz O. Lassen
  • Patent number: 5165496
    Abstract: A control valve is opened (moved from its neutral position) by rotation of a steering wheel to conduct fluid from a pump to a steering meter device that controls the amount of fluid fed to a steering motor arrangement. When the steering motor piston has been displaced by a distance corresponding to the angle of rotation of the steering wheel, the control valve is moved by the steering meter device from its opened condition to its neutral position. A pilot valve controlled actuating device is provided to short circuit the steering meter device to permit continued fluid flow from the pump to the steering motor device and provide a mechanical braking force to the meter device to block rotation thereof and thereby the movement of the control valve to its neutral position. The braking mechanism is resiliently urged to a non-braking position.
    Type: Grant
    Filed: July 1, 1991
    Date of Patent: November 24, 1992
    Assignee: Danfoss A/S
    Inventors: Poul H. H. Pedersen, Thorkild Christensen, Johannes V. Baatrup, Svend E. Thomsen
  • Patent number: 5165447
    Abstract: In a hydraulic power steering control unit of the type having an inner steering wheel operated control member which has limited relative rotation movement with respect to outer control member which controls a conventional steering motor, passages are provided in these members to control the pressures therebetween to prevent jamming thereof.
    Type: Grant
    Filed: March 2, 1992
    Date of Patent: November 24, 1992
    Assignee: Danfoss A/S
    Inventors: Niels Arbjerg, Steffen Lorentzen
  • Patent number: 5165652
    Abstract: The coil arrangement of an electromagnetic valve has a stationary core that is provided with a stop face for having one end of an armature abut thereagainst. The stop face and the one end of the armature is located in a damping chamber, the other end of the armature mounting a closure member for abutting against a valve seat to block fluid flow therethrough. Between the armature and the guide member there is a throttle path that fluidly connects the damping chamber with the valve seat chamber. The electromagnetic valve is especially suitable for conveying contaminated media.
    Type: Grant
    Filed: October 7, 1991
    Date of Patent: November 24, 1992
    Assignee: Danfoss A/S
    Inventor: Holger Nicolaisen
  • Patent number: 5165320
    Abstract: Disclosed is an arrangement that includes a piston cylinder unit having pressure chamber in which fluid acts in opposition to a spring piston combination, a pressure generator and a fluid conduit extending between a tank and the tank. A first and a second valve are connected in series between the pressure generator and tank with the pressure chamber being in fluid communication with the connection between the valves. In known arrangements of the above type there is dead play wherein not every control signal corresponds to a defined position of the piston in the cylinder. However as disclosed herein the setting accuracy is improved by a throttle in parallel with valve that is fluidly connected between the pressure chamber and the piston cylinder unit. Also third and fourth valves may be connected in series between the pressure generator and tank and have a fluid connection between the third and fourth valves to the unit pressure chamber that is opposite the first chamber to provide a bridging circuit.
    Type: Grant
    Filed: November 12, 1991
    Date of Patent: November 24, 1992
    Assignee: Danfoss A/S
    Inventor: Kjeld Ravn
  • Patent number: 5148735
    Abstract: The actuator has a moving spool in a valve body for controlling the pressure medium inflow to and from an actuating cylinder. The pressure medium in the valve body is conducted to each end of the spool in order to use the pressure medium to move the spool when desired. A pair of piezo-electric or magnetostrictive servomotors are provided to actuate on/off valves, each of which controls a flow of pressure medium from each end of the spool. Upon actuation of a servomotor, a valve is opened so that the pressure at the corresponding end of the spool decreases causing a shift of the spool in that direction. The servomotors are triggered by brief electrical digital signals.
    Type: Grant
    Filed: July 17, 1991
    Date of Patent: September 22, 1992
    Assignee: Danfoss A/S
    Inventor: Sead Veletovac
  • Patent number: 5143286
    Abstract: A thermostat top part is mounted to a valve housing for rotation relative thereto and is axially removably secured thereto. The thermostat top part has a retaining ring surrounding and rotatable relative to a hollow cylindrical base foot. A clamping element is mounted by the base foot for radial movement between a position abutting against a clamping face of the valve housing that is tapered axially toward the housing abutment face in a radial inward direction for retaining the top part on the valve housing and a radial outward position permitting the thermostat top part being axially removed from the valve housing. A torsion spring resiliently urges the retainer ring to rotate in a direction for moving the clamping element radially inwardly.
    Type: Grant
    Filed: November 25, 1991
    Date of Patent: September 1, 1992
    Assignee: Danfoss A/S
    Inventors: Henning B. Hansen, Stefan P. Maroti, Bjarne Frederiksen, Knud Lykkegaard
  • Patent number: 5131237
    Abstract: A refrigeration system having compressor controls responsive to the heat load on the system. Each selected evaporator of the system has a thermostatic switch unit which includes an associated temperature sensor in proximity to the evaporator. The thermostatic switch unit has an operating range with ON and OFF threshold values and function to operate an electromagnetic valve which controls the refrigerant admitted to the evaporator. The heat load to which the compressor controls are responsive is derived from the accumulated ON and OFF times of the switch insert.
    Type: Grant
    Filed: February 25, 1991
    Date of Patent: July 21, 1992
    Assignee: Danfoss A/S
    Inventor: Knud V. Valbjorn
  • Patent number: 5127284
    Abstract: The setting apparatus includes a housing having an operating grip mounted thereon for pivotal movement about a first axis between a neutral position and a second position for adjusting a signal changing device. An abutment member is mounted by the housing to pivot about an axis extending perpendicular to the first axis and has a face in abutting relationship to the face of a pressure face member. A rod and a spring are mounted by the operating grip for longitudinal movement and rotary movement relative to the grip to retain the pressure member face in abutting relationship to the abutment member face for selectively adjusting the neutral position of the operating grip upon rotation of the rod and resiliently urging the operating grip to its neutral position when the operating grip is moved out of its various selected adjusted neutral positions.
    Type: Grant
    Filed: October 9, 1990
    Date of Patent: July 7, 1992
    Assignee: Danfoss A/S
    Inventor: Geert Jorgensen
  • Patent number: 5123508
    Abstract: A housing mounts an input shaft with a clutch flange thereon, and an output shaft with an annular friction member thereon to divide the housing clutch chamber into two separate operating chambers. A brake ring has a first friction face facing the friction lining of the friction member while the friction member has a second friction lining facing the clutch flange. The friction member is axially displaceable a limited amounted by a compressible fluid for controlling the movement of the friction linings axially between the linings and into engagement with one of the brake member and the clutch flange. Each of the clutch flange and the brake ring has an annular groove concentric to the coextensive axes of the shafts that opens to the axially adjacent friction lining.
    Type: Grant
    Filed: April 1, 1991
    Date of Patent: June 23, 1992
    Assignee: Danfoss A/S
    Inventor: Svend P. Pedersen
  • Patent number: 5117647
    Abstract: The expansion valve has an inlet connection fluidly connected to a main valve while the main valve is fluidly connected through an outlet connection to the inlet of the evaporator of a refrigeration system. The main valve has a housing that includes a main valve chamber and a valve seat for fluidly connecting the inlet connection to the main valve chamber and a valve member movable between an open position and blocking fluid flow through the valve seat from the inlet connection to the valve chamber. A pressure operated servo arrangement is disposed in the main valve chamber for controlling the movement of the valve element and opens to the pressure outlet of a pilot valve arrangement. The pilot valve arrangement is disposed in a branch path that opens to inlet connection and to the valve chamber downstream of the valve set for controlling the fluid pressure at the pressure outlet.
    Type: Grant
    Filed: April 8, 1991
    Date of Patent: June 2, 1992
    Assignee: Danfoss A/S
    Inventor: Knud V. Valbjorn
  • Patent number: 5115685
    Abstract: The torque meter has a shaft with a reduced diameter intermediate portion with a sleeve that at its axial opposite ends is in fixed axial and rotational relation thereto. The sleeve intermediate portion has circumferentially extending lugs that are joined to the sleeve end portions. The lugs circumferentially opposite their juncture to the sleeve end portion mount an armature. The rotation of the sleeve ends relative to one another axially displaces the armature and changes an electric or magnetic field. At least one coil is in fixed axial and rotational relationship to the sleeve for detecting a change in the field for measuring the torque.
    Type: Grant
    Filed: May 29, 1990
    Date of Patent: May 26, 1992
    Assignee: Danfoss A/S
    Inventors: Geert Jorgensen, Torben Jensen, Niels Gade
  • Patent number: 5107584
    Abstract: An electric unit with a plurality of electric circuit elements is manufactured to connect terminals of the electric circuit elements directly using flexible conductors and the entire electric unit is covered by a deformable and contractile tube. Entrance and exit of conductors for connecting the electric unit and an external electric circuit are sealed with waterproof synthetic resin in a watertight manner. At least a portion of the electric circuit unit is capable of being bent. The electric unit can be applied to electric appliances having various shapes and further be easily mounted in a space, for example, such as a corner of the electric appliance even if the available space is curved.
    Type: Grant
    Filed: October 9, 1990
    Date of Patent: April 28, 1992
    Assignee: Danfoss A/S
    Inventor: Hideaki Takeda
  • Patent number: 5097920
    Abstract: Hydraulic steering mechanism is extended through an aperture in an end wall in a housing that has a pressure chamber, the steering mechanism including a slide rotatable with the steering column. An axial bearing is mounted by the end wall for rotatably mounting the steering mechanism while the aperture axially opposite end portion mounts a sealing ring between the housing and the steering mechanism. Axially between the sealing ring and the bearing there is a pressure reduction ring providing an annular gap with the slide for throttling the flow of fluid from the pressure chamber to a fluid collecting chamber that at least in part is defined by the pressure reduction and sealing rings. Fluid can flow from the collecting chamber through a housing outlet. The pressure reduction ring has an enlarged diameter flange for sealingly engaging the end wall and being clamped between the wall and the axial bearing.
    Type: Grant
    Filed: August 30, 1990
    Date of Patent: March 24, 1992
    Assignee: Danfoss A/S
    Inventors: Poul H. Holm-Pedersen, Ivar Rasmussen
  • Patent number: 5093771
    Abstract: An inverter circuit which converts d.c. from a d.c. source to single or multiple phase a.c.. Two semiconductor switching elements for each phase are connected in series between two poles of a d.c. source. A signal generator provides a pulse width modulated signal for operating the switching elements. Blocking elements are provided between the signal generator and the switching elements. A control circuit senses current flow at the a.c. output and selectively enables the blocking elements in accordance with the direction of the current flow to prevent short circuiting between the switching elements.
    Type: Grant
    Filed: January 8, 1990
    Date of Patent: March 3, 1992
    Assignee: Danfoss A/S
    Inventor: Nils-Ole Harvest
  • Patent number: 5085400
    Abstract: A stepped piston is axially displaceable in the stepped piston valve chamber and has a front face facing the front face of the valve seat and an axially opposite surface formed at the juncture of its piston head portion to its reduced diameter shaft portion. The piston has an axial through-bore that opens to fluid connecting bore in the valve housing while the housing has a second fluid connecting bore. The piston is displaceable in the chamber between an open position permitting substantial fluid flow between the connecting bores and a closed position having its front face resting against the valve seat face to permit a leakage flow gap between the faces when pressurized fluid acts against the piston surface and block substantial fluid flow between the first bore and the second bore. A spring in the chamber urges the piston toward its closed position.
    Type: Grant
    Filed: May 28, 1991
    Date of Patent: February 4, 1992
    Assignee: Danfoss A/S
    Inventor: Hans C. Petersen
  • Patent number: 5085769
    Abstract: An oil burner pump that includes a housing having a filter cartridge chamber that has an access opening which is closable by a removable cover. A filter cartridge is removable inserted into the chamber and is securable to the cover to be removed from the chamber when the cover is removed. The cartridge has opposite end portions and filter fabric extended between the opposite end portions, one of the end portions being removably securable to the cover.
    Type: Grant
    Filed: July 2, 1990
    Date of Patent: February 4, 1992
    Assignee: Danfoss A/S
    Inventors: Jorn H. Klausen, Peter Froslev
  • Patent number: 5069075
    Abstract: The flow meter works on the Coriolis principle and has a measuring tube and at least two energy converters. At least one of the energy converters is an oscillation exciter for oscillating the tube to generate a wave traveling along the tube and an oscillation detector. An evaluating circuit uses the speed of travel of waves in the direction of flow of fluid through the tube and in the direction opposite the direction of flow to determine the mass flow of fluid through the tube.
    Type: Grant
    Filed: July 3, 1990
    Date of Patent: December 3, 1991
    Assignee: Danfoss A/S
    Inventors: Henning M. Hansen, Frands W. Voss
  • Patent number: 5062305
    Abstract: The measuring tube is for an electromagnetic flow meter and has a tube member made of a non-magnetic material that is provided with opposite through passages that have electrodes extended therethrough. An insulating lining of an enamel priming layer coats the inner surface of the tube member and fills the gaps between the electrodes and the tube member surfaces defining the through passages, the lining also including an covering enamel layer covering the priming layer surface that is within the tube member interior. The end faces of the electrodes that are in the tube member interior have the enamel material cleared therefrom. The priming layer may be formed by filling the tube member with a priming enamel slip, pouring out the slip material, cleaning the electrode end surfaces that are within the tube member interior and then heating to melt the slip material and then cooling. The covering layer may be formed by the same steps.
    Type: Grant
    Filed: May 29, 1990
    Date of Patent: November 5, 1991
    Assignee: Danfoss A/S
    Inventors: Henry Hansen, Leif Studsgaard, Erik Laursen