Class Notes

Current as of: June, 1999
Click HD for Main Headings
Click for All Classes

Internet Version by PATENTEC © 1999      Terms of Use

432 /   HD   HEATING


Classification: 432/

This is the residual class for apparatus and related methods for the generation of heat and its application to materials; and for subcombinations and adjuncts specialized to such heating. Note. Patents issued prior to 1945 have not in all instances been classified by their claimed disclosure so the placement of these older patents does not necessarily indicate lines of classification.



1. Class 266, Metallurgical Apparatus takes the following combinations of a heating furnace with additional structure for a metallurgical purpose:

a. A heating furnace with additional structure for cooling or quenching a solid metal object after heating is in Class 266 if the disclosure is limited to the metallurgical treatment of metals. If the disclosure is generic to metals and nonmetals or if the material has not been specified, Classification is in Class 432. It is noted that glass and ceramic article are commonly "annealed". Accordingly, a disclosure of "annealing" without a specification of material is in Class 432.

b. Those heating furnaces which are limited by disclosure to heating solid metal articles and which have structure for supplying or producing a special atmosphere either protective or treating, are in Class 266. Furnaces not elsewhere provided for having gas supplying or producing means will be found in this (432) Class.

c. A heating furnace in which material is melted having additional structure for the collection of flow, separation, dispensing or mixing of melted metal is in Class 266 when the sole disclosure relates to the handling of metal.

d. A heating furnace in combination with a fume arrester in which the sole disclosure relates to the arresting of metallurgical fume, i.e. of condensate of metallic vapor generated from a charge of metal ore or intermediate metal product, is in Class 266. A residual heating furnace with means separating dust or slag from the furnace discharge is classifiable in Class 432, subclasses 67+. 2. A residual heating furnace not specialized to metallurgical use as indicated above is in Class 432. It is noted that a "reverbatory" furnace or a furnace in which a steel making crucible is heated may be a Class 432 heating subcombination of general utility even though the disclosed charge includes metal or metal ore with reactive ingredients combined therewith or separately fed into the heating chamber.


A furnace heated by reacting a charge of solid material with gaseous oxygen to produce heat and a chemical transformation of charge material and not having a separate heat generator is in Class 266 when the sole disclosed specific use of the apparatus is to produce metal or an intermediate metal product. It is considered that a "blast furnace," a "cupola furnace," and a "converter" are this type of Class 266 apparatus unless there is a positive indication that the apparatus may be used to treat a specific nonmetal. Also, in the absence of a disclosure that the apparatus of utility in treating nonmetal producing materials, the term "sintering" applied to a furnace treating bulk particulate material with gas is considered to indicate metallurgical apparatus for Class 266.



4, Baths, Closets, Sinks, and Spittoons,

360, for a dry sanitary closet having a means for drying or burning the discharge.

5, Beds,

284, for an accessory device for heating or cooling a bed.

26, Textile: Cloth Finishing,

81, 92, and 106 for apparatus for expanding (e.g., stretching, spreading) running length webs of cloth which further include means for heating or drying the cloth.

34, Drying and Gas or Vapor Contact With Solids, 280+, for a process limited to drying even though involving

the burning of fuel, and for a residual process of contacting a solid with a gas or vapor; and appropriate subclass for (1) a heating apparatus specialized to drying or (2) an apparatus specialized to contacting solid with a gas. A merely nominal heating means may be included in the structure of the apparatus of (1) and (2).

37, Excavating,

226, for apparatus for excavating, compacting and melting snow.

43, Fishing, Trapping, and Vermin Destroying,

144, for a burner specialized to destroying vermin.

47, Plant Husbandry,

1.44, for a process or apparatus specialized for use in plant husbandry for flame cultivation.

48, Gas: Heating and Illuminating,

61, for apparatus in which heating or illuminating gas is produced by heating carbonaceous material in a chamber.

53, Package Making,

127, for a package making apparatus having means to heat or cool the contents of the package; and subclasses 373.7+ for a means to complete a package by heating or cooling a seam to seal the package. 68, Textiles: Fluid Treating Apparatus,

15, for a clothes washing machine combined with means to heat the tub or for applying heat to liquid within the tub.

95, Gas Separation: Processes, for processes of gas separation perfected by the application of heat.

96, Gas Separation: Apparatus, for apparatus for gas separation perfected with heating means.

105, Railway Rolling Stock,

451, for apparatus for thawing a frozen load in railway rolling stock.

106, Compositions: Coating or Plastic,

739+, for a process of (1) making cement, (2) making a cement intermediate product or (3) for treating calcareous or argillaceous material if the treatment is disclosed as being for the purpose of making "cement" or lime".

110, Furnaces, appropriate subclasses for a solid fuel

combustion furnace or subcombination thereof; and

173+, for a door usable on either a heating furnace or a solid fuel combustion furnace.

118, Coating Apparatus, 47, for coating apparatus including means for carbonizing, flame contact, or burning off of coating ingredient; and subclasses 641+ for coating apparatus having means for the radiant heating of the work or coating.

119, Animal Husbandry,

302+, for a brooder and subclasses 311+ for an incubator.

126, Stoves and Furnaces, for the apparatus for the application of heat, and for the stove and furnace elements specifically provided for in the various subclasses.

134, Cleaning and Liquid Contact With Solids,

105+, for a cleaning and liquid contact with solids device having a nominal heating, cooling or heat exchange means.

156, Adhesive Bonding and Miscellaneous Chemical Manufacture,

497, for a surface bonding device with gas, vapor or flame contact means for the work; and subclasses 583.1+ for a heated press for a surface bonding apparatus.

159, Concentrating Evaporators, appropriate subclass for a residual process or apparatus for concentrating a liquid by heat.

164, Metal Founding, appropriate subclass for the molding of free flowing liquid metal.

165, Heat Exchange, appropriate subclass for a residual method or apparatus for the transfer of heat from one material to another.

(1) Note. A heat generator is considered to make the arrangement special to heating except where the structure is a combined heating and cooling device. 196, Mineral Oils: Apparatus,

104+, for apparatus for vaporizing mineral oils.

237, Heating Systems, appropriate subclass for an apparatus or process of heating a room, chamber or other enclosing structure by a system delivering fluid heated by a heat generator to the room or structure or to a heat exchanger in the room or structure.

266, Metallurgical Apparatus, appropriate subclass, for apparatus concerned with the extraction of metals from their ores, with the refining of metal, and with the establishing a physical or mechanical property of a solid metal object by a heat treatment related to the composition of the object. The relationship of the two classes is as follows:

297, Chairs and Seats,

180.1, for a heated chair or seat.

366, Agitating,

144, for an agitator combined with means to heat the material during agitation, for purposes other than drying, involving no structural detail of the heating or heat transfer means and no new relationship of the heating structure to the agitating structure.

373, Industrial Electrical Heating Furnaces, appropriate subclass for a furnace specialized to the use of electricity as the heat source and particularly adapted to metallurgical and related work. Such furnace is generally characterized by electrical heating means within the chamber containing the material to be heated, the heating means being either an arc, a resistance, the material itself, or a combination of such means, and is further characterized by adaptation for operation on a granular material, such as crushed ore, or for handling molten material fusing at a very high temperature, the material in both cases being received immediately within the body of the furnace.

376, Induced Nuclear Reactions: Processes, Systems, and Elements, appropriate subclass for a nuclear reactor type of heat generator delivering heat energy to a material or to a power generator.

392, Electric Resistance Heating Devices, 307+, for a specific electrical heating device combined with nonelectric heating means; and appropriate subclass for a residual device for the generator of heat by electricity and the utilization of the heat wherein there is involved an electrical characteristic or electrical structure that is more than merely nominal.

422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, appropriate subclasses for heating sterilizers; combustion or reaction device for purifying gas, or with means for recovering, mixing, separating, or otherwise handling as a product formed in the device; autoclaves for carrying out a reaction at high temperature; a cooler or digest or not otherwise provided for; and residual chemical apparatus.

452, Butchering,

73, for for singeing devices and subclasses 74+ for scalding devices.

607, Surgery: Light, Thermal, and Electrical Application,

1, for a device for treating an abnormal condition of a living body with light, heat, or electricity.