Patents Assigned to Danfoss
  • Patent number: 3999707
    Abstract: An air conditioning system comprising a room to which conditioned air having temperature and volume parameters is delivered. Temperature sensing means is provided for sensing the temperature of the air in the room. Air supply means responsive to the sensing means is provided in an air supply duct. Damper means is also mounted in the duct for varying the effective area of the opening of the duct. A regulating means is provided for controlling the damper to vary the air velocity in accordance with a constant value for the expression Ar.1.sup.-.sup.3/2, where Ar is the Archimedean number, and 1 represents the effective area of the opening. The temperature sensing means also controls the volume parameter of the air supply which air supply has a constant temperature parameter.
    Type: Grant
    Filed: September 8, 1975
    Date of Patent: December 28, 1976
    Assignee: Danfoss A/S
    Inventor: Peter Vilhelm Nielsen
  • Patent number: 3995533
    Abstract: The invention relates to a hydraulic steering unit for automotive vehicles. A main feature of the unit is that pressure relief means are provided for relieving excessively high pressures developed in the unit which are caused by the steered wheels encountering road obstacles. The unit includes a pump, a drain tank and a working motor which is connectable to the wheels to be steered. The working motor has complementary expansible chamber means and a control valve is connected to the motor with a pair of supply and exhaust conduits which are selectively connectable to the pump and the tank by the control valve. A shunt line is provided between the pump and the tank and a pressure relief valve is in the shunt line. A manually operated valve controlled by a steering wheel is connected to the pump and the drain tank. A pair of control lines are connected to the manually operated valve which are selectively connectable to the pump and the drain tank by the manually operated valve.
    Type: Grant
    Filed: February 26, 1975
    Date of Patent: December 7, 1976
    Assignee: Danfoss A/S
    Inventor: Ulf Martin von Huth Smith
  • Patent number: 3994556
    Abstract: The invention relates to an electrical junction box for use with snap-in type printed circuit board modules. The junction box is connected to some form of electrical apparatus such as an electrical motor. The junction box has terminals to which conductors from the electrical apparatus such as a motor can be clamped. The junction box has a slot with the terminals in alignment on one wall thereof. The slot receives a circuit board module which has contacts which are arranged to respectively engage the terminals in the slot.
    Type: Grant
    Filed: November 3, 1975
    Date of Patent: November 30, 1976
    Assignee: Danfoss A/S
    Inventors: Jens Peter Jensen, Leif Borge Tandrup
  • Patent number: 3986100
    Abstract: A control circuit for controlling a supply of D.C. voltage to the input of an inverter. The circuit includes a control arrangement and apparatus for adjusting the D.C. voltage supply in accordance with signals applied to the control arrangement. The circuit also includes a current sensor for sensing the current supplied to the inverter, a sensing device for an A.C. voltage component connected across the input to the inverter, and apparatus for applying signals to the control arrangement in accordance with the current sensed by the sensor and the A.C. voltage component sensed by the sensing device.
    Type: Grant
    Filed: December 12, 1974
    Date of Patent: October 12, 1976
    Assignee: Danfoss A/S
    Inventors: Hans Mogens Beierholm, Niels Juul Henriksen
  • Patent number: 3981191
    Abstract: Ultrasonic signals are transmitted alternately upstream and downstream in a fluent media. A reference signal timed to occur at the estimated time of arrival of the alternate signals is used to ascertain whether the actual signals arrive earlier or later than the reference signal. Control circuitry responsive to the early and late signals generates two signal levels associated with transmission direction which adjusts the time position of the reference signal until it coincides with the actual arrival times. One signal level is related to flow velocity. The other signal level is related to sound velocity in the fluent media.
    Type: Grant
    Filed: August 11, 1975
    Date of Patent: September 21, 1976
    Assignee: Danfoss A/S
    Inventors: Alvin E. Brown, Niels Thun
  • Patent number: 3981075
    Abstract: A method for making a heavy duty PTC resistor with a pressed and sintered hollow cylindrical body of a ceramic composition which has two end faces in a radial plane with a connection contact on each end face.
    Type: Grant
    Filed: October 14, 1975
    Date of Patent: September 21, 1976
    Assignee: Danfoss A/S
    Inventor: Holger Wilhelm Vind
  • Patent number: 3978879
    Abstract: The invention relates to a control valve assembly for a hydrostatic control system such as power steering assembly. A common control valve assembly of this type has relatively rotatable inner and outer elements connected respectively to a vehicle steering wheel and a servomotor. Paired holes in the inner and outer element permit the flow of fluid therethrough when the unit is in its neutral position with the paired holes in respective registration. In hydrostatic steering system of this type impact is sometimes applied to the steering wheel when the working motor connected to the steered wheels is suddenly loaded, e.g. when the wheels strike a stone. Such impacts on the steering wheel are avoided by providing a one-way valve in a section of the working path through which fluid flows to the working motor. Pressure regulating valve means, excess pressure valve means and emergency control valve means are associated with the one-way valve assembly.
    Type: Grant
    Filed: June 26, 1974
    Date of Patent: September 7, 1976
    Assignee: Danfoss A/S
    Inventors: Poul Erik Termansen, Thorkild Christensen
  • Patent number: 3978883
    Abstract: The invention relates to a furnace type air throttle assembly which operates in a manner to supply a constant volume of air per unit time. This is done with a bellows and throttle arrangement in which (1) the total pressure at the inlet, which is the sum of the dynamic and static pressure, is utilized to expand the bellows and move the throttle in a closing direction and (2) static pressure and weight means are utilized to compress the bellows and move the throttle in the opening direction.
    Type: Grant
    Filed: May 2, 1975
    Date of Patent: September 7, 1976
    Assignee: Danfoss A/S
    Inventor: Jorgen Hartvig Petersen
  • Patent number: 3979710
    Abstract: A heating regulator which is responsive to effective outdoor temperatures and the temperature of a heated fluid supplied by a boiler. The regulator has an adjustably positionable pointer which represents a characteristic curve. The regulator includes three slide members with the pointer being pivotally mounted on one of the slide members for a translatory movement therewith and pivotal movement relative thereto. Two potentiometers are operated by two of the slide members and one of the slide members actuates the third slide member which in turn effects pivotal movement of the pointer.
    Type: Grant
    Filed: February 18, 1975
    Date of Patent: September 7, 1976
    Assignee: Danfoss A/S
    Inventor: Aksel Jespersen
  • Patent number: 3975620
    Abstract: An electric storage heater assembly which is charged at night when energy rates are low and utilized during the day when the rates are higher. A fan unit is controlled by a thermostat to extract heat from the heater assembly. The previous days experience relative to the total time the fan operates is a measure of the heat to be stored during the off hours. An integrator with input and output switching elements activated by a clock controlled time switch is used in connection with a three position room thermostat, the positions being for high and low temperatures and neutral. The input switching element has positive and negative terminals and during day operation, the time the thermostat is in its low temperature position is summed through the positive terminal. The time the thermostat is in its high temperature position is subtracted from the accumulated value of the integrator through the negative terminal.
    Type: Grant
    Filed: January 2, 1975
    Date of Patent: August 17, 1976
    Assignee: Danfoss A/S
    Inventors: Knud Julius Hallgreen, Poul Christian Carlos Iversen
  • Patent number: 3970282
    Abstract: The invention relates to a magnetic valve assembly of the type in which an energized armature moves a valve closure member to an open position and a load spring in compression maintains the valve closure member closed when the armature is nonenergized. Relative movement between the armature member and the closure member is provided and an energy storing spring between these members resists the relative movement. In two embodiments the energy storing spring is stressed in compression in one and in tension in the other. The valve closure member does not begin to move until the armature causes the energy storing spring to be stressed to an extent equal to a predetermined stressing of the load spring. With this mode of operation the armature stroke is longer than the stroke of the closure member and this results in a smaller magnetic system being sufficient for a given valve system.
    Type: Grant
    Filed: December 9, 1974
    Date of Patent: July 20, 1976
    Assignee: Danfoss A/S
    Inventor: Egon Jorgen Hansen
  • Patent number: 3969986
    Abstract: The invention relates to a radial piston type pump comprising a casing, a shaft, two or more piston carriers mounted on and driven by the shaft, and a curved track surrounding the piston carriers. The piston carriers are axially movable on the shaft and pressure chamber and scaling means are provided between adjacent carriers to bias them in opposite directions against the internal casing walls which form a chamber in which the carriers are rotatably mounted. Fluid inlet and outlet means in one of these casing walls has fluid communication with the inlet and outlet passages in the carriers and the biasing of a carrier against this wall serves to provide sealing between the relatively rotating surfaces to minimize the leaking of fluid between these surfaces.
    Type: Grant
    Filed: January 11, 1973
    Date of Patent: July 20, 1976
    Assignee: Danfoss A/S
    Inventor: Carl Verner Ohrberg
  • Patent number: 3967229
    Abstract: A heavy duty PTC resistor with a pressed and sintered hollow cylindrical body of a ceramic composition which has two end faces in a radial plane with a connection contact on each end face.A heavy duty PTC resistor sintered body of a ceramic composition which has two end-faces carrying a connection contact; the invention also concerns a method of manufacturing such PTC-resistor.High duty PTC-resistors are required for some purposes. If for example a PTC-resistor is used as a starting device for a single-phase motor, it has to be designed to deal with almost the entire mains voltage and to carry power of 500 W or more. The usual cylindrical bodies, provided at their two end-faces with connection contacts, frequently exhibit cracks under loads of this kind.A high-duty PTC-resistor is thus known (German Patent Specification OS 1 465 349) which is made up of a stack of solid or hollow flat cylindrical discs, the end-faces of the superposed discs being interconncted by a contact layer.
    Type: Grant
    Filed: November 6, 1974
    Date of Patent: June 29, 1976
    Assignee: Danfoss A/S
    Inventor: Holger Wilhelm Vind
  • Patent number: 3964943
    Abstract: The invention relates to an electrical resistor with a SiC body, particularly for ignition or heating purposes, and to a method of producing such electrical resistor.
    Type: Grant
    Filed: November 29, 1974
    Date of Patent: June 22, 1976
    Assignee: Danfoss A/S
    Inventor: Niels Lervad Andersen
  • Patent number: 3965349
    Abstract: The invention relates to a programmable timing device of the type which controls a utility unit such as a heating plant on a daily and weekly schedule. The timing device includes clock works and a rotatable unit driven by the clock works. A reflecting disc having a reflecting surface is mounted on the rotatable unit for rotation therewith. A stationary unit holds a light source which directs a light beam towards the reflecting disc. A program disc is mounted on the rotatable unit between the reflecting disc and the stationary unit. The program disc has a predetermined form for masking certain portions of the reflecting surface from the light beam as the rotatable unit rotates relative to the stationary unit. The timing device includes a light sensor for receiving a reflection of the light beam from the reflecting surface. The light sensor is held by the stationary unit in close proximity to the light source.
    Type: Grant
    Filed: February 18, 1975
    Date of Patent: June 22, 1976
    Assignee: Danfoss A/S
    Inventor: Aksel Jespersen
  • Patent number: 3946983
    Abstract: The invention relates to a pilot controlled, magnetic type of valve having a diaphragm with the outer edge floatably attached to the housing. Excessive deformation of the diaphragm is prevented by providing a supporting ring which is axially movable in relation to the body of the valve and has a conical surface which is engaged by the diaphragm and to which the diaphragm conforms when the valve is in an open position.
    Type: Grant
    Filed: August 7, 1974
    Date of Patent: March 30, 1976
    Assignee: Danfoss A/S
    Inventor: Lorenz Asmus Engberg
  • Patent number: 3945457
    Abstract: A hydraulic steering apparatus comprising a sump, a pair of motors controlling the vehicle parts to be steered, a steering wheel operated control device for controlling the motors, a continuously operable pump between the sump and control device, a pair of control conduits connected to the control device and meeting at a junction, a pair of stroke limiting control valves in the control conduits alternately actuable by the two motors, and an exhaust conduit from the junction to the sump. A short circuiting path shunting the pump, a pressure operated switching valve in the sort circuiting path, a pressure operated pilot valve for controlling the switching valve, a spur connection between the pilot valve and the exhaust conduit downstream from the spur connection to cause concomitant opening the pilot valve and the switching valve.
    Type: Grant
    Filed: January 13, 1975
    Date of Patent: March 23, 1976
    Assignee: Danfoss A/S
    Inventor: Carl Ivar Olsen
  • Patent number: 3946304
    Abstract: The invention relates to a phase initiation control circuit for a three phase system which comprises three sets of blocking elements of the TRIAC type. Regulation is achieved by displacing the moment at which a control impulse is sent to each blocking element to render it conducting for the remainder of the half cycle. Associated with each phase is a continuously chargeable capacitor which, upon a predetermined voltage being reached, discharges to produce a control impulse and also is completely discharged through the collector emitter path of a junction transistor at the zero cross-over of the particular voltage phase. The capacitors are charged through charging transistors and are discharged to produce said control impulses through unijunction transistors and impulse transformers.
    Type: Grant
    Filed: May 24, 1972
    Date of Patent: March 23, 1976
    Assignee: Danfoss A/S
    Inventor: Flemming Thorsoe
  • Patent number: 3943092
    Abstract: The method relates to a method for producing a shaped drying filter. Drying agent particles are mixed with an epoxide containing binding agent and the mixture is compressed to form a shaped body at a high temperature. The epoxide resin components react with each other at a particular temperature. In the method hereof the mixing step is performed below that particular temperature and the compressing step is performed above that temperature. The hardening only takes place during the pressing operation and the mixture can thus be stored for as long a time as desired.
    Type: Grant
    Filed: October 15, 1974
    Date of Patent: March 9, 1976
    Assignee: Danfoss A/S
    Inventor: Jorn Marius Schmidt
  • Patent number: 3941033
    Abstract: The invention relates to a hydraulic steering apparatus comprising a continuously operating pump, an operating motor for controlling the parts to be steered, a control device which is adjustable by the steering wheel and which, in its neutral position, connects the pump to a tank through a short-circuiting path. The control device has two operating positions in which the pump is connected to one side or the other of the operating motor and connects the other side of the operating motor to the tank. The control device has a control element connected to a steering wheel and a following element connected to a metering motor and these elements are relatively displaceable to a limited extent. Apparatus is provided to prevent the steering parts moved by the operating motor from striking mechanical abutments.
    Type: Grant
    Filed: November 15, 1973
    Date of Patent: March 2, 1976
    Assignee: Danfoss A/S
    Inventor: Carl Ivar Olsen