Patents Assigned to Danfoss
  • Patent number: 4547825
    Abstract: The invention relates to apparatus and an arrangement for starting and protecting an electrically driven motor-compressor unit. A protector switch and a PTC resistor have a common housing with a bore and slot construction adapted for clamping the housing to the external pressure tube of the motor-compressor unit.
    Type: Grant
    Filed: February 16, 1984
    Date of Patent: October 15, 1985
    Assignee: Danfoss A/S
    Inventor: Holger V. Vind
  • Patent number: 4547842
    Abstract: The invention relates to apparatus for supplying an electric consumer with a high DC voltage which includes provisions for minimizing the danger and hazard of electrical shocks associated therewith. The apparatus includes a power circuit and a measuring control circuit which are separated by high ohmic resistors and an optocoupler.
    Type: Grant
    Filed: October 20, 1983
    Date of Patent: October 15, 1985
    Assignee: Danfoss A/S
    Inventors: Hans M. Beierholm, Niels Thun
  • Patent number: 4545259
    Abstract: The invention relates to an ultrasonic measuring apparatus of the type having a measuring path which extends in a tube between two ultrasonic converters. More accurate measuring results are obtained by providing axially spaced inserts in the measuring tube for changing the velocity profile of the medium flowing through the tube so that the average of the upstream and downstream signals is substantially proportional to the mean flow velocity of the medium flowing through the tube.
    Type: Grant
    Filed: October 3, 1983
    Date of Patent: October 8, 1985
    Assignee: Danfoss A/S
    Inventors: Hans-Erik K. Jensen, Niels Abildgaard, Steen H. Nielsen
  • Patent number: 4538717
    Abstract: The invention relates to a step drive assembly which includes a rotatable operating unit for operating a tool or knife or the like. The assembly has a change-over clutch for selectively connecting the operating unit to a continuously running motor or a brake. Control apparatus for the assembly includes a disk rotatable with the operating unit having teeth and spaces therebetween forming zones and a sensor unit for scanning the zones and outputting a pulse train. An evaluating circuit responsive to the pulse train outputs a positioned stop signal and an overload stop signal to effect a braking operation.
    Type: Grant
    Filed: February 4, 1983
    Date of Patent: September 3, 1985
    Assignee: Danfoss A/S
    Inventors: Knud Blohm, Egon Krogh
  • Patent number: 4535678
    Abstract: The invention relates to a steering control unit for a bidirectional servomotor which is connectable to steerable wheels. A steering wheel controlled quantity setting unit of a known type has ports connectable to a pump and a return tank and two control ports through which metered quantities of fluid flow to opposite sides of the servomotor and to other parts of the apparatus for actuating the servomotor. A directional control valve for selectively directing pressurized fluid from a power circuit to opposite sides of the servomotor is controlled by a control circuit containing the setting unit. A utility valve having the pressure regulating and control and power valve capabilities required for this type of apparatus is characterized by having only a single slide spool for performing all of these functions.
    Type: Grant
    Filed: September 16, 1982
    Date of Patent: August 20, 1985
    Assignee: Danfoss A/S
    Inventors: Svend E. Thomsen, Thorkild Christensen
  • Patent number: 4535590
    Abstract: The invention relates to a thermal servomotor which includes two operating elements particularly bellows boxes, which act oppositely on a valve actuating bridge. Each operating element has a temperature-dependent filling. Each operating element is connected to a relatively small container having a volume on the order of 0.2 cm.sup.3 by a capillary passage which has the effect of partially thermally insulating each operating element from the associated container. Each container contains the medium of the filling that determines the pressure and separate heating apparatus is associated with each of the two containers.
    Type: Grant
    Filed: March 29, 1984
    Date of Patent: August 20, 1985
    Assignee: Danfoss A/S
    Inventors: Finn Jacobsen, Jens J. Molbaek, Jan Zangenberg, Poul S. Dam
  • Patent number: 4535280
    Abstract: The invention relates to a stabilizing circuit for an inverse rectifier motor control which includes a D.C. voltage supply having a D.C. voltage regulator followed by a smoothing intermediate circuit. A frequency control circuit converts the supply voltage from the intermediate circuit to a frequency control voltage. Following the frequency control circuit is a generator for converting the frequency control voltage to control signals for the inverse rectifier motor control.
    Type: Grant
    Filed: March 28, 1984
    Date of Patent: August 13, 1985
    Assignee: Danfoss A/S
    Inventors: Nils-Ole Harvest, Anna Melamed
  • Patent number: 4533303
    Abstract: A geroter hydrostatic steering control is disclosed in which the directional valve is spring biased to a neutral position. The rotor, the commutating valve, the rotor casing and the directional valve are all axially aligned adjacent to each other thus reducing the overall axial length of the device.
    Type: Grant
    Filed: November 21, 1983
    Date of Patent: August 6, 1985
    Assignee: Danfoss A/S
    Inventors: Hans C. Petersen, Erik Kyster, Svend E. Thomsen
  • Patent number: 4532764
    Abstract: The invention relates to a reaction hydraulic control unit for use in steering systems of the type having a differential type servomotor. In steering systems of this type having a differential piston type servomotor there exists a condition during the piston centering operation when the unit is in neutral wherein the servomotor piston has a slower centering speed when the transfer of medium is from the nonrod side to the rod side of the servomotor. The unequal centering times causes annoyance to drivers because that condition is transmitted to the steering wheel. This problem is addressed by providing steering controlled valving for exhausting fluid from the nonrod chamber of the servomotor to the system tank after the control unit has returned to its neutral position and during the centering operation of the servomotor piston.
    Type: Grant
    Filed: January 7, 1983
    Date of Patent: August 6, 1985
    Assignee: Danfoss A/S
    Inventor: Poul H. H. Pedersen
  • Patent number: 4529166
    Abstract: The invention relates to a magnetic valve assembly of the type in which a solenoid plunger upon excitation by a magnetic coil is displaceable against a housing end face having a valve seat. The plunger has a bore in which is disposed a closing element. A return spring in the plunger bore biasing the plunger away from the valve seat is between the far end of the plunger and a fixed abutment element which passes through the plunger. The plunger has a hole surrounding the abutment element which is sized to allow the plunger engage the valve seat and to limit the movement of the plunger away from the valve seat.
    Type: Grant
    Filed: August 30, 1984
    Date of Patent: July 16, 1985
    Assignee: Danfoss A/S
    Inventors: Jorn H. Klausen, Laurits B. Rasmussen, Svend Hansen
  • Patent number: 4527595
    Abstract: The invention relates to a flow regulator in which a diaphragm of elastically deformable material is disposed between a pressure chamber at supply pressure and an end face of a base member having open radially extending grooves. A supply passage extends from the regulator inlet circumferentially around the diaphragm into fluid communication with the grooves and a discharge passage is axially disposed in the base member in fluid communication with the radially inward ends of the grooves. Pressure variations in the supply passage cause the diaphragm to cover varying lengths of the grooves to vary the throttling effects of the grooves. The regulator is adapted for different ranges of flow quantities by providing two or more grooves in the face of the base member and by providing valving apparatus for selectively connecting one or more of the grooves to the supply passage.
    Type: Grant
    Filed: June 2, 1983
    Date of Patent: July 9, 1985
    Assignee: Danfoss A/S
    Inventors: Peter Jorgensen, Jens J. Molbaek, Volker Spies, Poul C. Dyhr-Mikkelsen, Poul S. Dam
  • Patent number: 4525769
    Abstract: The invention relates to an equipment box for a power converter which includes a rear wall with vertical cooling ribs on the outside and having a planar surface on the insides upon which electrical components can be mounted. The box further has base, top and side walls and at least one conductor plate arranged on a component carrier which is pivotally mounted internally of the box. The side walls are pivoted to the rear wall by hinges, formed by a vertical groove on one wall and a rib engaged therein on the other wall. In this construction use is made of the fact that the rear wall with its cooling ribs constitutes a very stiff constructional element. The side walls can be mounted on it directly and, by reason of the pivotable arrangement, the side walls can be accurately positioned to be at right-angles to the rear wall. In this position they are then fixed by the retaining wall and tolerance variations which are unavoidable in walls of large area will not lead to stresses in the finished housing.
    Type: Grant
    Filed: March 16, 1984
    Date of Patent: June 25, 1985
    Assignee: Danfoss A/S
    Inventor: Kjeld Lehmann
  • Patent number: 4524806
    Abstract: A pressure valve for a compressor of the hermetically encapsulated type. The valve includes a valve plate with a valve seat and upstanding pins on which at least one catch plate is placed to limit the stroke of a closing member formed by a valve leaf spring. The valve seat is disposed in an elongated depression of the valve plate and the pins are formed on an insert spring into the recess.
    Type: Grant
    Filed: February 3, 1984
    Date of Patent: June 25, 1985
    Assignee: Danfoss A/S
    Inventor: Bendt W. Romer
  • Patent number: 4523739
    Abstract: The invention relates to a magnetic valve for a refrigeration plant. The valve is of the type having a magnetic coil with a plug member of magnetic material projecting into a central bore thereof. The yoke has parallel limbs. A housing block member is mounted in fixed relation to the coil and in spaced relation to the plug member to provide an armature space. A plunger type armature is disposed in the armature space where its stroke is limited at both ends thereof. The armature has a first end face magnetically pulled against the plug when the coil is energized and a return spring opposing the energizing force of the coil. The armature has a second end face at the other end thereof which is pushed into engagement with said housing block member by the return spring when the coil is deenergized.
    Type: Grant
    Filed: April 11, 1984
    Date of Patent: June 18, 1985
    Assignee: Danfoss A/S
    Inventors: Claus J. Johansen, Jens K. Jark, Thorvardur S. Stefansson
  • Patent number: 4518147
    Abstract: A thermostatic valve assembly having a rotatably adjustable insert for varying the throttle resistance of the valve. The insert has a skirt with a spiral shape to effect a first varying cross section for the valve chamber in which the insert is disposed and the skirt also has an inclined section to effect a second varying cross section for the valve chamber.
    Type: Grant
    Filed: December 30, 1983
    Date of Patent: May 21, 1985
    Assignee: Danfoss A/S
    Inventors: Erik E. Andresen, Svend P. Pedersen
  • Patent number: 4515555
    Abstract: The invention relates to a vapor burner for liquid fuel having an elongated gasifying chamber preceeding a combustion chamber which is heatable to gasifying temperatures by electrical heating apparatus. The gasifying chamber has an inlet for liquid fuel and an outlet for the gasified fuel feeding into the combustion chamber. The gasifying chamber is formed so that no forced air is admissible to the inlet thereof. The heating apparatus heats the gasifying chamber along the length thereof and includes apparatus surrounding the outlet end thereof to form a glow zone heatable to the fuel mixture ignition temperature.
    Type: Grant
    Filed: October 26, 1983
    Date of Patent: May 7, 1985
    Assignee: Danfoss A/S
    Inventors: Jorgen H. Petersen, Peter J. M. Clausen, Hilmar O. Rasmussen
  • Patent number: 4514678
    Abstract: The invention relates to a digital control device for an inverse rectifier having controllable switching elements for driving an A.C. motor operable at a variable frequency. The device has a pulse generator for producing timing pulses at a multiple of the frequency of the inverse rectifier frequency and a location counter 26 controlled by the timing pulses. A control store in the form of a ROM has at least two storage zones occupied by different controlling tables of which the data characterizes the periodically changing signal pattern for the ignition and extinction signals of the controlled switching elements of the inverse rectifier. A table selecting apparatus which, depending on setting and operating parameters, delivers a preparatory selecting signal for the desired control table and, after a change in this selecting signal, appropriately switches the storage zone over.
    Type: Grant
    Filed: March 28, 1984
    Date of Patent: April 30, 1985
    Assignee: Danfoss A/S
    Inventor: Kjeld Kuckelhahn
  • Patent number: 4508262
    Abstract: The invention relates to a thermostatic valve assembly of the type in which the working element containing the vapor-liquid filling is housed in the temperature setting control knob. A threaded adjusting connection between the knob and an axially moveable unit which controls the compression of the setting spring provides rugged and simple construction.
    Type: Grant
    Filed: September 12, 1983
    Date of Patent: April 2, 1985
    Assignee: Danfoss A/S
    Inventors: Svend P. Pedersen, Jens J. Molbaek, Allan H. Hansen
  • Patent number: 4508263
    Abstract: The invention relates to a thermostatic valve assembly of the type in which a working element containing a vapor-liquid filling is housed in the temperature setting control knob. The assembly includes a housing having a projecting portion. There is a threaded adjusting connection between the knob and a base unit which is attachable to the housing projection portion. The invention is directed to specific constructions for attaching the base unit to the projection portion.
    Type: Grant
    Filed: September 12, 1983
    Date of Patent: April 2, 1985
    Assignee: Danfoss A/S
    Inventors: Svend P. Pedersen, Soren N. Wrang, Jens J. Molbaek
  • Patent number: 4506771
    Abstract: A method and apparatus for operating a switching device such as a clutch or brake for a moveable element such as a shaft which is driveable by a prime mover such as a rack and pinion device. The clutch selectively connects the shaft to the prime mover and the brake alternately and selectively connects the shaft to the housing. A motor sinusoidally reciprocates the rack by way of an eccentric drive and the rack drives a pinion on the input side of a pneumatic clutch and brake unit. The clutch is always operated in only one direction of movement and the moveable shaft can thereby be intermittently driven in one direction. A continuously rotating motor shaft carries a signal generator disc having a signal generating track in the form of recesses which are scanned photoelectrically. An operating signal which holds the clutch engaged during one half period is received by the signal generator and delivered by a control device.
    Type: Grant
    Filed: July 26, 1982
    Date of Patent: March 26, 1985
    Assignee: Danfoss A/S
    Inventors: Egon Krogh, Knud Blohm