Metcal, Inc.

Amp LLC

Rodney L Derbyshire

Thomas H McGaffigan

Paul F Busch

Douglas Wilkerson

A heat shrinkable sleeve or the like is heated by a ferromagnetic member which in turn is heated by a varying magnetic field, the ferromagnetic having a Curie temperature above the shrink temperature of the sleeve whereby when the sleeve is heated to its shrink temperature it tightly groups the members to be joined. Preferably a constant temperature is employed so that the ferromagnetic material will not rise above its Curie temperature.

Temperature self-regulating induction apparatus

A connector which acts upon itself contains a fusible bonding material the connector forming a part of a temperature autoregulating electrical heater whereby upon application of a generally constant a.c. current to the heater, the temperature of the heater rises to and is maintained at slightly above the melting temperature of the fusible material. The circuit which includes the autoregulating heater may take many forms, and in one embodiment a crimping tool forms part of the circuit; in another embodiment, a wire or wires to be joined to the connector as well as the connector form part of the heating circuit; while in another embodiment, a heat shrinkable conductor or plastic or fusible plastic may be employed to grasp an object to be joined to the connector or other object or block the flow of fusible material while in still another embodiment, the fusible material, upon flowing to a prescribed final location, disconnects the system from the current source, and/or may connect a second heating circuit to a source. Autoregulation is achieved at about the Curie temperature of a magnetic material incorporated in the system as a connector, as a layer of a connector, as the jaws of the crimping tool, as part of a member to be joined to another member and the like. In some embodiments, the connector serves as the secondary of an inductive source.

Clam shell heater employing high permeability material

A self-regulating porous heater regulates the temperature of fluid passing through it. This device includes at least one layer of a porous material which has a magnetic permeability inversely related to temperature over a given range. Due to conductor skin effects, changes in permeability cause changes in the depth of penetration of alternating current passing through the magnetic layer. Changes in the depth of penetration, in turn, result in changes in resistance--the less the depth the greater the resistance--and in I.sup.2 R Joule heat. The combined result of these effects is to provide more heat where the temperature of the fluid and the layer through which the fluid flows is below a specified temperature which is related to the Curie temperature of the layer. Significantly, by properly defining pore dimensions, the heater device can filter contaminants from a fluid as it flows therethrough. In a preferred mode, a porous heater device is included in a chemical reaction chamber. Fluids flowing through the chamber are closely controlled in temperature through each reaction zone by the heater device (through which the fluids flow) and by an optional cooling element. By defining the structure of the chamber and the rate of fluid flow, close control of other reaction parameters can also be achieved. Such close control permits greater specifity of reaction yield and greater safety in various exothermic reactions.

Self-regulating porous heating device

A connector which acts upon itself contains a fusible bonding the connector forming a part of a temperature autoregulating electrical heater whereby upon application of a generally constant a.c. current to the heater, the temperature of the heater rises to and is maintained at slightly above the melting temperature of the fusible material. The circuit which includes the autoregulating heater may take many forms, and in one embodiment a crimping tool forms part of the circuit; in another embodiment, a wire or wires to be joined to the connector as well as the connector form part of the heating circuit; while in another embodiment, a heat shrinkable conductor or plastic or fusible plastic may be employed to grasp an object to be joined to the connector or other object or block the flow of fusible material while in still another embodiment, the fusible material, upon flowing to a prescribed final location, disconnects the system from the current source, and/or may connect a second heating circuit to a source. Autoregulation is achieved at about the Curie temperature of a magnetic material incorporated in the system as a connector, as a layer of a connector, as the jaws of the crimping tool, as part of a member to be joined to another member and the like. In some embodiments, the connector serves as the secondary of an inductive source.

Heat shrink sleeve with high mu material

A blind rivet or bolt is rendered fluid tight by applying heat activated sealant to some or all of the surfaces of the rivet that contact surfaces of the structure into which the rivet is inserted. The sealant is activated by a temperature self regulating heater formed by applying ferromagnetic material to appropriate locations on the rivet and heating the ferromagnetic material by an energizing structure associated with the rivet actuation tool, the structure depending upon whether the heater is activated by flux coupling from a coil or by ohmic heating.

Rivet with integral heater

An elongated flexible heater strip is provided having a transmission line section and a heater section employing a high mu material to control temperature at the Curie temperature of the high mu material; the above elements and a return buss being confined in a conductive sheath having a plurality of transverse slots to render the strap flexible, so that it may be cinched about a member to be heated; a strip of conductive material, such as copper, extending at least along the transmission line section interiorly of said sheath to reduce the resistance thereof and increase the current carrying capacity of the strap.

Heater straps

A connector (33) which acts upon itself contains a fusible bonding material (35,37) the connector (33) forming a part of a temperature autoregulating electrical heater whereby upon application of a generally constant a.c. current to the heater, the temperature of the heater rises to and is maintained at slightly above the melting temperature of the fusible material (35,37). The circuit which includes the autoregulating heater may take many forms, and in one embodiment a crimping tool forms part of the circuit; in another embodiment, a wire or wires to be joined to the connector as well as the connector form part of the heating circuit; while in another embodiment, a heat shrinkable conductor or plastic or fusible plastic may be employed to grasp an object to be joined to the connector or other object or block the flow of fusible material while in still another embodiment, the fusible material, upon flowing to a prescribed final location, disconnects the system from the current source, and/or may connect a second heating circuit to a source. Autoregulation is achieved at about the Curie temperature of a magnetic material incorporated in the system as a connector, as a layer of a connector, as the jaws of the crimping tool, as part of a member to be joined to another member and the like. In some embodiments, the connector serves as the secondary of an inductive source.

Connector containing fusible material and having intrinsic temperature

A self-regulating porous heater device regulates the temperature of fluid passing through it. This device includes at least one layer of a porous material which has a magnetic permeability inversely related to temperature over a given range. Due to conductor skin effects, changes in permeability cause changes in the depth of penetration of a.c. current passing through the magnetic layer. Changes in the depth of penetration, in turn, result in changes in resistance--the less the depth the greater resistance--and in I.sup.2 R Joule heat. The combined result of these effects is to provide more heat where the temperature of the fluid and the layer through which the fluid flows is below a specified temperature which is related to the Curie temperature of the layer. The device can have a laminate structure including a porous magnetic layer and at least one other magnetic layer or at least one low resistance nonmagnetic layer or a combination thereof, which may or may not be porous. By properly defining pore dimensions, the heater device can filter contaminants from a fluid as it flows therethrough. Switching between a normal operating temperature and an elevated temperature for vaporizing or burning off contaminants at the pores is provided. In a preferred mode, a porous heater device is included in a chemical reaction chamber for exothermic reactions.

Self-regulating porous heater device

The lid is hermetically sealed to an associated box by a gasket in the form of a sealant covered temperature autoregulating heater.

Self heating gasket for hermetically sealing a lid to a box

A simple, highly flexible, virtually massless, temperature autoregulating heater primarily useful for soldering has an energizing circuit that may be integral with or separate from the heater element, which element has a ferromagnetic material energized via the circuit from a constant current source whereby regulation occurs about the Curie temperature of the magnetic material. The energizing circuit may be in the form of a printed circuit conductor formed on a thin layer of Kaptan or like high temperature insulating material having the heater formed on the reverse side thereof or having a sticky substance thereon so that the energizing circuit may be temporarily adhered to the heater and removed after use. Alternatively, the energizing circuit may be formed directly on Nomex paper or the like; a quite thin paper with a sticky backing. The magnetic material may be one member of a laminate of materials having different conductive and magnetic properties whereby upon the magnetic material achieving Curie temperature, the current spreads into a layer of lower resistivity; providing large autoregulating ratios. The unusually high wattage-to-weight ratio of the heater permits large quantities of heat to be applied to a load within a very short interval which together with the ability to concentrate the applied heat to a small, well defined area permits rapid heating of the load, an essential characteristic where damage to insulation must be prevented.

Thin, flexible, autoregulating strap heater

Apparatus and process for selectively heat treating at least a portion of an article in the field with autoregulated heating. The autoregulated heating is provided by a heater including at least a first magnetic material disposed along the portion of the article to be heat treated. The first magnetic material has a magnetic permeability which sharply changes at temperatures at or near the autoregulating (AR) temperature thereof. The changes in permeability result in corresponding changes in the skin depth of the first magnetic material and, hence, the heating produced therein responsive to a.c. current passing therethrough. By maintaining the a.c. current constant in amplitude and frequency, the first magnetic material and the portion of the article are regulated at substantially the AR temperature of the first magnetic material. By selecting the first magnetic material to have AR temperature substantially corresponding to the temperature at which metal anneals, tempers, hardens, softens, stress relieves or the like, heat treating at an autoregulated temperature is achieved. The autoregulated heater can be incorporated into the article or can be applied to the article thereafter, in each case permitting in field heat treating. Autoregulated heating can also be achieved by any of various multilayer structures to provide desired autoregulation effects.

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Menlo Park, CA, United States of America

Rodney L Derbyshire