Thermomagnetic Patents (Class 335/208)
  • Patent number: 9498782
    Abstract: A method for classifying articles comprising magnetocalorically active material according to magnetic transition temperature comprises providing a source of articles to be classified, the source comprising articles comprising magnetocalorically active materials having differing magnetic transition temperatures, sequentially applying a magnetic field at differing temperatures to the source, the magnetic field being sufficient to exert a magnetic force on the source that is greater than the inertia of a fraction of the articles causing the fraction of the articles to move and produce an article fraction, and collecting the article fraction at each temperature to provide a plurality of separate article fractions of differing magnetic transition temperature, thus classifying the articles comprising magnetocalorically active material according to magnetic transition temperature.
    Type: Grant
    Filed: March 13, 2013
    Date of Patent: November 22, 2016
    Assignee: VACUMMSCHMELZE GMBH & CO. KG
    Inventor: Matthias Katter
  • Patent number: 9417292
    Abstract: A thermomagnetic sensor includes a thermomagnetic probe that includes a ferromagnetic material having a temperature-dependent magnetic permeability characterized by a maximum magnetic permeability value at a temperature below a Curie temperature of the ferromagnetic material. The thermomagnetic sensor further includes an alternating magnetic field source to produce an alternating magnetic field in a vicinity of the thermomagnetic probe to facilitate a measurement of the temperature-dependent magnetic permeability as function of temperature remotely using a thermomagnetic effect. A predetermined relationship between the temperature-dependent magnetic permeability and temperature in a range between the maximum magnetic permeability value and the Curie temperature provides a measurement of a temperature local to the thermomagnetic probe.
    Type: Grant
    Filed: June 6, 2012
    Date of Patent: August 16, 2016
    Assignee: HRL Laboratories, LLC
    Inventors: Chia-Ming Chang, John Wang, Geoffrey P. McKnight, Ping Liu
  • Publication number: 20130315757
    Abstract: An actuator includes a first part having a magnetomotive element and configured to absorb heat up to at least a first temperature; a second part arranged so as to face the first part; a temperature-sensitive magnetic body provided between the first part and the second part and configured to move between a first position for contact with the first part and a second position for contact with the second part, the temperature-sensitive magnetic body having a Curie point lower than the first temperature and higher than a temperature of the second part; and a restoring part configured to restore the temperature-sensitive magnetic body from the first position to the second position.
    Type: Application
    Filed: July 29, 2013
    Publication date: November 28, 2013
    Applicant: FUJITSU LIMITED
    Inventors: Osamu Tsuboi, Yoshihiro Mizuno, Norinao Kouma
  • Patent number: 7947200
    Abstract: A temperature switch comprises a material (14) which melts and concomitantly undergoes a change in an electrical characteristic at a predetermined temperature. The temperature switch also includes at least two electrical contacts (10, 12) for detecting the change in the electrical characteristic. The material (14) comprises an organic cation and an anion and is preferably an ionic liquid.
    Type: Grant
    Filed: April 17, 2008
    Date of Patent: May 24, 2011
    Assignee: Kidde IP Holdings Limited
    Inventor: Alexandra Georgina Redcliffe Gordon
  • Patent number: 7920037
    Abstract: A fault interrupter and load break switch includes a trip assembly configured to automatically open a transformer circuit electrically coupled to stationary contacts of the switch upon the occurrence of a fault condition. The fault condition causes a Curie metal element electrically coupled to at least one of the stationary contacts to release a magnetic latch. The release causes a trip rotor of the trip assembly to rotate a rotor assembly. This rotation causes ends of a movable contact of the rotor assembly to electrically disengage the stationary contacts, thereby opening the circuit. The switch also includes a handle for manually opening and closing the electrical circuit in fault and non-fault conditions. Actuation of the handle coupled to the rotor assembly via a spring-loaded rotor causes the movable contact ends to selectively engage or disengage the stationary contacts.
    Type: Grant
    Filed: May 8, 2008
    Date of Patent: April 5, 2011
    Assignee: Cooper Technologies Company
    Inventors: Kurt Lawrence Lindsey, Randal Vernon Malliet
  • Patent number: 7857996
    Abstract: A temperature switch comprises a material (14) which melts and concomitantly undergoes a change in an electrical characteristic at a predetermined temperature. The temperature switch also includes at least two electrical contacts (10, 12) for detecting the change in the electrical characteristic. The material (14) comprises an organic cation and an anion and is preferably an ionic liquid.
    Type: Grant
    Filed: October 18, 2006
    Date of Patent: December 28, 2010
    Assignee: Kidde IP Holdings Limited
    Inventor: Alexandra Georgina Redcliffe Gordon
  • Publication number: 20090243772
    Abstract: A nanoswitch device comprising: at least one stationary element (52) and at least one element (50) which is at least partially made of a magnetic material and which is movable with respect to the stationary element, means of activating the movable element, comprising: and at least one first and one second magnetic means (30, 30?, 40, 40?) each having a planar shape, defining a first and a second plane, in order to generate remanent magnetization in a direction contained within said first plane or perpendicular to this first plane, means (36, 36?) for reversing the direction of the remanent magnetization of at least one of said first and second magnetic means.
    Type: Application
    Filed: March 27, 2009
    Publication date: October 1, 2009
    Applicant: COMMISSARIAT A L'ENERGIE ATOMIQUE
    Inventors: Lise Bilhaut, Philippe Andreucci, Laurent Duraffourg, Bernard Viala
  • Patent number: 6476703
    Abstract: The invention describes a control unit of a valve mechanism with an electromagnetic coil (1) where the electromagnetic coil (1) is electrically and mechanically connected to the control unit via a connection device which has an electrically conducting spring-mounted connecting ridge (10).
    Type: Grant
    Filed: January 24, 2001
    Date of Patent: November 5, 2002
    Assignee: Framatone Connectors International
    Inventors: Hans-Otto Geltsch, Josef Koiner
  • Patent number: 5990773
    Abstract: In a thermal switch device having a reed switch, a temperature-sensitive magnetic cylinder (1) and cylindrical permanent magnets (2a, 2b) disposed around the reed switch (3), and an insulator case (7), the case is provided with an inner cylinder (5) formed in an inner space of the case. The reed switch is supported in the inner cylinder, and the temperature-sensitive magnetic cylinder and the cylindrical permanent magnets are fitted on the inner cylinder. A heat conductor member (6) is attached to the case to be partially exposed outside the case while partially be in contact with the temperature-sensitive magnetic cylinder and the cylindrical permanent magnets.
    Type: Grant
    Filed: October 1, 1998
    Date of Patent: November 23, 1999
    Assignee: Tokin Corporation
    Inventor: Takeshi Sengoku
  • Patent number: 5397948
    Abstract: A magnetic motor is shown having magnetic members situated in relatively close proximity to each other; relative movement between the magnetic members is brought about by bringing the temperature of at least one of the magnetic members to the curie temperature thereof, and subsequent relative movement between the magnetic members is brought about by having the temperatures of all of the magnet members less than the curie temperatures thereof.
    Type: Grant
    Filed: March 12, 1993
    Date of Patent: March 14, 1995
    Assignee: Nartron Corporation
    Inventors: Marty M. Zoerner, Stephen R. W. Cooper
  • Patent number: 5168545
    Abstract: A temperature operated control system, a temperature operated control device therefor and methods of making the same are provided, the temperature operated control device comprising a support, an electrical reed switch unit carried by the support, the reed switch unit comprising a reed switch and a temperature controlled fixed magnetic unit for causing the reed switch to be in a first operating condition thereof when the temperature sensed by the magnetic unit is at or below a first temperature setting and for causing the reed switch to be in a second operating condition thereof when the temperature sensed by the magnetic unit is at or above a second temperature setting, and a selector unit movably carried by the support and being operatively associated with the reed switch unit to adjust the temperature settings thereof within a certain range of temperature settings as the selector unit is moved relative to the reed switch unit.
    Type: Grant
    Filed: March 9, 1992
    Date of Patent: December 1, 1992
    Assignee: Robertshaw Controls Company
    Inventor: Lee A. Hart
  • Patent number: 5095295
    Abstract: A new type of reed switch is described. The switch is comprised of a fixed lead and a flexible reed made of a magnetic substance which are contacting in a glass enclosure. Two magnet rods are coaxially arranged in the same direction with a superconducting film therebetween. When the surrounding temperature is descended below Tc of the superconducting film, a dipole moment is formed across the superconducting film and moves the reed away from the lead by the magnetic force thereof.
    Type: Grant
    Filed: September 6, 1989
    Date of Patent: March 10, 1992
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Masashi Hongou
  • Patent number: 4745385
    Abstract: A temperature compensated switching relay with thermally effected switching delay should be of simple and compact construction and reliable in switching with precisely adjustable switching delay. For this purpose, the switching relay comprises a switching member (1) movable between two end positions and bearing a permanent magnet (2), with an inherent snapping action to actuate at least one switching contact (6), on opposite sides of the permanent magnet (2) in its direction of movement a first and a second paramagnetic member (3, 4) is provided, on the first paramagnetic member (3) a PTC resistor (5) feedable by a source of current is mounted, and in the end position of the switching member (1) at the second paramagnetic member (4) the distance (A) of the permanent magnet (2) from the first paramagnetic member (3) is less than its distance (B) from the second paramagnetic member (4). The ratios of the distances of the permanent magnet (2) from the paramagnetic members (3, 4) can expediently be adjusted.
    Type: Grant
    Filed: August 11, 1987
    Date of Patent: May 17, 1988
    Assignee: Ranco Incorporated
    Inventor: Guglielmo Rossi
  • Patent number: 4703296
    Abstract: A thermal reed switch assembly including two magnetic reed switches having two permanent magnets and at least two semicylindrical thermal magnetic members each having mutually different magnetic tansition points sandwiching the reed switch therebetween. An inner diameter of one thermal magnetic member may be larger than at least a second member therein increasing the sectional area ratio of the members.
    Type: Grant
    Filed: February 6, 1986
    Date of Patent: October 27, 1987
    Assignee: TDK Corporation
    Inventor: Tomio Katoh
  • Patent number: 4582675
    Abstract: A magnetic reed switch assembly for activating an electromagnetic grapple utilized to hold a control rod in position above a reactor core. In normal operation the magnetic field of a permanent magnet is short-circuited by a magnetic shunt, diverting the magnetic field away from the reed switch. The magnetic shunt is made of a material having a Curie-point at the desired release temperature. Above that temperature the material loses its ferromagnetic properties, and the magnetic path is diverted to the reed switch which closes and short-circuits the control circuit for the control rod electromagnetic grapple which allows the control rod to drop into the reactor core for controlling the reactivity of the core.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: April 15, 1986
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: John H. Germer
  • Patent number: 4516101
    Abstract: A air-flow-rate sensor having a thermo-magnetically operated switch including a U-shaped temperature sensitive ferromagnetic piece, a positive temperature characteristic thermister, and two terminal plates, which are stationarily mounted in an opening chamber of an insulator frame. The two terminal plates are for connecting the thermister to an external electric power source and are in contact with respective input electrodes on opposite surfaces of the thermister. One of the two terminal plates is formed in a generally arcuate form to elastically press the other terminal plate onto the ferromagnetic piece through the thermister. The thermo-magnetically operated switch is fixedly mounted on the frame by fitting its opposite terminals into grooves formed in the inner wall of the frame. Each terminal plate is also fixed to the frame by fitting both ends into another grooves formed in the inner wall of the frame.
    Type: Grant
    Filed: February 22, 1984
    Date of Patent: May 7, 1985
    Assignee: Tohoku Metal Industries, Ltd.
    Inventors: Michio Nemoto, Kiyokazu Yoshida, Tetsuro Baba
  • Patent number: 4509029
    Abstract: A thermal switch includes a reed switch surrounded by a centrally located, annular collar made of a ferrite material and a pair of annular permanent magnets spaced from the ends of the ferrite collar and positioned axially toward the ends of the reed switch. The magnetic spacing can be achieved by utilization of non-magnetic spacers, and the entire structure encapsulated to provide further durability, if desired.
    Type: Grant
    Filed: March 9, 1984
    Date of Patent: April 2, 1985
    Assignee: Midwest Components, Inc.
    Inventor: Fennimore N. Bradley
  • Patent number: 4504809
    Abstract: A miniature latching thermomagnetic relay is disclosed which offers high contact forces, small size, and low cost. Ferromagnetic material is placed upon heaters in a low thermal conductivity substrate. A permanent magnet beneath the substrate attracts a moving element above the substrate. Contact points on the substrate and the moving element from electrical connections.A control signal causes a heater to warm the ferromagnetic material, changing the saturation flux density of the material. This results in an unbalanced force on the moving element, causing it to rock about a pivot point to open or close connections as desired. Planar fabrication techniques may be used to construct the relay.
    Type: Grant
    Filed: May 15, 1984
    Date of Patent: March 12, 1985
    Inventors: Jonathan C. Lueker, Raymond A. Zandonatti
  • Patent number: 4456898
    Abstract: Thermal compensators comprising at least one metallic alloy in amorphous form which are especially useful in stabilizing magnetic devices under conditions of changing ambient operating temperature are provided.
    Type: Grant
    Filed: February 11, 1982
    Date of Patent: June 26, 1984
    Assignee: General Electric Company
    Inventor: Peter G. Frischmann
  • Patent number: 4454491
    Abstract: A circuit breaker or switch utilizes the Curie point temperature characteristics of an amorphous ferromagnetic metal in cooperation with a magnet to make or interrupt an electrical circuit upon the amorphous material being heated to its Curie point temperature. The circuit breaker has a planar base member with a raised projection which supports a stationary contact member so that the movable contact member overhangs the stationary contact member. The movable contact member is provided with a number of layers of amorphous ferromagnetic material, disposed adjacent the stationary contact, bringing the movable contact member into electrical contact with the stationary contact member. Upon reaching its Curie point temperature, the amorphous ferromagnetic material will become paramagnetic or nonmagnetic material, so that the inherent resiliency of the movable contact material causes the electrical circuit to be made or broken.
    Type: Grant
    Filed: May 10, 1982
    Date of Patent: June 12, 1984
    Assignee: Allied Corporation
    Inventor: Charles R. Martus
  • Patent number: 4434411
    Abstract: A temperature-sensitive switch is provided with a resilient movable cantilever composed of amorphous ferromagnetic material having a Curie point. The cantilever is adapted to carry a first contact member. A second contact member is disposed adjacent the first contact member for at least intermittently establishing electrical contact with the first contact member. A magnet is associated with and adapted to bias the cantilever to a first position that establishes electrical continuity between the first and second contact members. The cantilever is transformed from a ferromagnetic phase to a paramagnetic phase when its temperature exceeds the Curie point, whereby the cantilever assumes a second position in which the electrical conductivity is interrupted. The switch is lightweight, compact, economical to manufacture and reliable in operation.
    Type: Grant
    Filed: March 10, 1982
    Date of Patent: February 28, 1984
    Assignee: Allied Corporation
    Inventors: Philip M. Anderson, III, James E. Kearney, Scott E. Gordon
  • Patent number: 4414520
    Abstract: Thermostat comprises a heat sensitive body of ferromagnetic material and a movable magnet cooperating therewith. A pair of a contacts which are closed or open depending upon the position of the magnet are provided where the position in turn depends upon the temperature dependant magnetic properties of the sensitive body. The magnet is exposed to a counter force, that is oppositely directed to the attraction force, and a spring force on a pair of contacts has a contact making action in one position of the magnet and a contact opening action in another position of the magnet. More particularly the counter force and the spring force are exerted by one and the same snap spring, that acts between the movable contact formed as a contact tongue and the magnet.
    Type: Grant
    Filed: March 1, 1982
    Date of Patent: November 8, 1983
    Inventor: Jonny Ruuth
  • Patent number: 4414519
    Abstract: A temperature-sensitive relay is provided with a resilient, movable cantilever composed of amorphous ferromagnetic material having a Curie point. The cantilever is adapted to carry a first contact member. A second contact member is disposed adjacent the first contact member for at least intermittently establishing electrical contact with the first contact member. The relay is adapted to be connected to circuitry having a power source for providing an electrical current and a switching mechanism for activating the circuitry in response to a preselected condition. A magnet is associated with and adapted to bias the cantilever to a first position that interrupts electrical continuity between the first and second contact members. The cantilever is transformed from a ferromagnetic phase to a paramagnetic phase when its temperature exceeds the Curie point, whereby the cantilever assumes a second position in which the electrical continuity is established.
    Type: Grant
    Filed: March 10, 1982
    Date of Patent: November 8, 1983
    Assignee: Allied Corporation
    Inventors: Philip M. Anderson, III, Ronald K. Reich
  • Patent number: 4404538
    Abstract: A temperature switch includes a housing, a movable contact mounted in the housing for movement between a first and second position, a fixed contact mounted in the housing and operatively associated with the movable contact for engagement with the movable contact in the second position, a heat sensitive plate mounted in the housing and which constitutes an amorphous metal member with a highly expansible metal wherein the amorphous metal member is exposed to a predetermined region, the temperature of which is to be determined wherein deflection of the heat sensitive plate is caused by a temperature change in the region for movement of the movable contact with respect to the fixed contact.
    Type: Grant
    Filed: August 24, 1981
    Date of Patent: September 13, 1983
    Assignee: Aisin Seiki Co., Ltd.
    Inventor: Kojiro Mori
  • Patent number: 4389628
    Abstract: A thermo-magnetically operated switch having lower and higher operating points is maintained open below the lower operating point and above the higher operating point and is maintained closed between the two different operating points, and comprises a reed switch, two permanent magnets disposed alongside the reed switch over the respective reeds, a first ferromagnetic body having a Curie point corresponding to the higher operating point and disposed between the two magnets, and a second ferromagnetic body or bodies having a Curie point corresponding to the lower operating point and disposed along the two magnets. In order to improve reliability of the switch, two third ferromagnetic bodies having Curie points at or above the lower operating point are disposed to engage axial opposite ends of the second ferromagnetic body or bodies and the other pole faces of the magnets opposite the pole faces engage the first ferromagnetic body.
    Type: Grant
    Filed: May 29, 1981
    Date of Patent: June 21, 1983
    Assignee: Tohoku Metal Industries, Ltd.
    Inventors: Hiroyasu Sato, Yoshiharu Sato, Tetsuro Baba
  • Patent number: 4383231
    Abstract: A temperature switch includes a housing, a fixed contact positioned in the housing, a movable contact member mounted in the housing carrying a movable contact and urged to first and second positions where the movable contact is in abutment with or displacement from the fixed contact, respectively, a permanent magnet mounted in the housing, a thermally sensitive member mounted in the housing so as to be exposed to a region the temperature of which is to be determined wherein the thermally sensitive member includes a magnetically soft, amorphous metal member and is magnetically coupled to the permanent magnet, and an operating member which includes magnetic material wherein a first end thereof engages the movable contact member and a second end thereof opposite the first end is attracted to the thermally sensitive member against the resilience of the movable contact member, thereby causing displacement of the movable contact to the second position and wherein the thermally sensitive member includes a paramagnet
    Type: Grant
    Filed: August 28, 1981
    Date of Patent: May 10, 1983
    Assignee: Aisin Seiki Kabushiki Kaisha
    Inventors: Minoru Yamanaka, Mitsuyuki Suzuki, Hideo Haneda, Masatoshi Kato, Masataka Ohtsuki
  • Patent number: 4325042
    Abstract: A thermo-magnetically operated switch having two different and predetermined lower and higher operating points on a temperature scale so that it may be maintained open below the lower operating point and above the higher operating point and be maintained closed between the two different operating points comprises two permanent magnets, and two kinds of temperature sensitive ferromagnetic members in proximity to a reed switch. The two permanent magnets are disposed over respective reeds of the reed switch in a similar polar direction and with an axial space therebetween. Two temperature sensitive ferromagnetic members having a higher Curie point are disposed at opposite outer sides of both permanent magnets or at opposite ends of the reed switch, and are in contact with respective permanent magnets.
    Type: Grant
    Filed: May 13, 1980
    Date of Patent: April 13, 1982
    Assignee: Tohoku Metal Industries, Ltd.
    Inventors: Masanori Endo, Kentaro Horiuchi
  • Patent number: 4320370
    Abstract: A thermo-sensitive reed switch in which the thermo-sensitive magnetic element is slit parallel to the reeds in the element.
    Type: Grant
    Filed: April 28, 1980
    Date of Patent: March 16, 1982
    Assignee: TDK Electronics Company, Ltd.
    Inventors: Tomio Itou, Toshiyuki Kitagawa
  • Patent number: 4266517
    Abstract: A differential pressure switch device having a flexible diaphragm between two chambers subject to differential pressure, a permanent magnet movable with the diaphragm against a biasing force when pressure differences occur in the chambers, a thermo ferrite combined with the magnet for cooperation therewith, and a reed switch assembly actuated by the movement of the magnet and through the action of the thermo ferrite which becomes magnetic or non-magnetic depending on the temperature.
    Type: Grant
    Filed: June 21, 1979
    Date of Patent: May 12, 1981
    Inventors: Naoji Sakakibara, Nobuyuki Hashimoto
  • Patent number: 4266211
    Abstract: A thermostatic switch having a magnetic armature made of a Curie point alloy which changes its magnetic permeability as a function of an increase or decrease in the temperature. The thermoswitch may be normally open or normally closed so that the switch will close or open with a change in temperature.
    Type: Grant
    Filed: April 24, 1978
    Date of Patent: May 5, 1981
    Inventor: Herman Ulanet
  • Patent number: 4224588
    Abstract: Electric relay comprising flexible-blade switches having multiple operational thresholds. In this relay, the most sensitive switches are within the coil whereas the least sensitive switches are located outside the coil, the magnetic circuit being directed toward the outside switches by the use of magnetic flux detectors. Moreover, the operational thresholds of the switches are adjustable by the use of magnetic shunts disposed in the coil and in the flux detectors, one of the shunts being constituted by a material chosen for its Curie point.
    Type: Grant
    Filed: June 22, 1978
    Date of Patent: September 23, 1980
    Assignee: Orega Circuits et Communication
    Inventors: Gerard Holvoet, Michel Nicolas
  • Patent number: 4208643
    Abstract: In a switching device having first and second conductor elements and an operating mechanism shiftable to and from a first position wherein the conductor elements are electrically connected to each other to establish a conductive path therebetween. The device includes a body of mercury, and a mercury wettable porous member between the mercury body and the first conductor element so that the mercury from the body may be forced through the porous body to establish the above-mentioned electrical connection. When the shiftable mechanism is shifted into the first position, the mercury is withdrawn from the first conductor element by the wettable porous member to disconnect the electrical circuit.
    Type: Grant
    Filed: June 5, 1978
    Date of Patent: June 17, 1980
    Assignee: Gulf & Western Manufacturing Company
    Inventors: Alvin A. Snaper, Gary B. Zulauf
  • Patent number: 4121184
    Abstract: An electromagnetically controlled, temperature-sensitive (ECTS) reed switch comprising a temperature-sensitive reed switch with an electromagnetic coil spirally wound around the exterior thereof for initiating a switching action of the reed switch independently of the ambient temperature of the switch.
    Type: Grant
    Filed: December 27, 1976
    Date of Patent: October 17, 1978
    Assignee: General Electric Company
    Inventors: Leonard R. Dinkler, Jerry Herrin
  • Patent number: 4092586
    Abstract: A temperature-responsive circuit comprising an ECTS reed switch and an interrogation means for determining the operability and accuracy of the temperature-responsive portion of the circuit.
    Type: Grant
    Filed: October 20, 1975
    Date of Patent: May 30, 1978
    Assignee: General Electric Company
    Inventors: Leonard R. Dinkler, Jerry Herrin
  • Patent number: 4023128
    Abstract: A temperature responsive reed switch having magnetic reed pieces, a permanent magnet disposed near a contact of the reed switch and being magnetized in an axial direction of the reed switch, two temperature responsive magnetic materials disposed adjacent the ends of the permanent magnet in the axial direction of the reed switch and a magnetic yoke disposed adjacent the outer surfaces of the temperature responsive magnetic material.
    Type: Grant
    Filed: February 20, 1976
    Date of Patent: May 10, 1977
    Assignee: TDK Electric Co., Ltd.
    Inventors: Tomio Itou, Michio Ishikawa, Tokio Furuse
  • Patent number: 4005726
    Abstract: A hot fluid is directed through a valved conduit inlet. Downstream of the inlet, the conduit divides into a pair of outlets through which the hot fluid flows. The flow through the outlets is controlled by a pair of vertically oriented valves linked together by a V-shaped linkage and weight biased toward the closed position such that when one valve is open the other is closed, and vice versa. The valve actuation means comprises a permanent magnet mounted on the housing in close proximity to each valve; each valve has mounted thereon and exposed to the hot fluid a magnetic material. Thus, when the magnetic material on the open valve is heated above its Curie temperature, the material loses its attraction for the permanent magnet and the weight bias closes that valve and simultaneously moves the other valve close enough to the permanent magnet to be held open thereby. When that valve's magnetic material is heated above the Curie temperature it in turn closes and the other valve opens.
    Type: Grant
    Filed: June 24, 1975
    Date of Patent: February 1, 1977
    Inventor: Herbert H. Fowler
  • Patent number: 4004259
    Abstract: A thermomagnetic switch is mountable on a chamber wall to extend into a liquid filled chamber. A reed switch in the switch is controlled by the strength of a magnetic field produced by a cylindrical magnet surrounding the reed switch. The magnetic flux passing through the reed switch is varied by a ferromagnetic cylindrical element having a magnetic permeability varying with temperature that shunts magnetic flux at a level varying with temperature. A ferrous slug or shaft adjacent to the reed switch is movable to shunt a selectable portion of the magnetic flux and permit a fine temperature adjustment. A method of adjusting the operating temperature of switch reduces the magnetic strength of the magnet in the switch in small increments while the switch is exposed to a selected temperature until the switch operates to establish its operating temperature.
    Type: Grant
    Filed: June 25, 1975
    Date of Patent: January 18, 1977
    Assignee: Square D Company
    Inventor: Ward Barry Krause
  • Patent number: 3978299
    Abstract: A liquid-level detecting device comprises a float for moving in accordance with the liquid level, a permanent magnet mounted in said float and a reed switch which is fixed to a stationary member and arranged for opening and closing in accordance with the movement of said permanent magnet and a thermoferrite member which is provided near said permanent magnet. The thermoferrite member has a Curie point at a critical temperature where it loses its magnetism thereby cutting an affection of said permanent magnet to said reed switch.
    Type: Grant
    Filed: May 29, 1975
    Date of Patent: August 31, 1976
    Assignee: Nippondenso Co., Ltd.
    Inventor: Norio Takai
  • Patent number: 3976961
    Abstract: An electromagnetic oven is provided with a control system comprising a ferrite sensor located within the oven, a magnetic property detector coupled to the sensor, and control means responsive to signals from the detector.
    Type: Grant
    Filed: September 16, 1974
    Date of Patent: August 24, 1976
    Assignee: Chemetron Corporation
    Inventor: Donald G. Moore
  • Patent number: RE29837
    Abstract: An electromagnetic oven is provided with a control system comprising a sensor located within the oven, a detector coupled to the sensor, and control means responsive to signals from the detector. In one embodiment, the control means activate a counter which, upon a predetermined number of operations, signals a condition of the load within the oven and may modify subsequent energy inputs to the load.
    Type: Grant
    Filed: March 26, 1976
    Date of Patent: November 14, 1978
    Assignee: Chemetron Corporation
    Inventor: Donald G. Moore