F
SECTION F — MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
 F01 - 
F42

Note(s)

Guide to the use of this subsection (classes F01-F04)

The following notes are meant to assist in the use of this part of the classification scheme.

  1. In this subsection, subclasses or groups designating "engines" or "pumps" cover methods of operating the same, unless otherwise specifically provided for.
  2. In this subsection, the following terms or expressions are used with the meanings indicated:
    • "engine" means a device for continuously converting fluid energy into mechanical power. Thus, this term includes, for example, steam piston engines or steam turbines, per se, or internal-combustion piston engines, but it excludes single-stroke devices. "Engine" also includes the fluid-motive portion of a meter unless such portion is particularly adapted for use in a meter;
    • "pump" means a device for continuously raising, forcing, compressing, or exhausting fluid by mechanical or other means. Thus, this term includes fans or blowers;
    • "machine" means a device which could equally be an engine and a pump, and not a device which is restricted to an engine or one which is restricted to a pump;
    • "positive displacement" means the way the energy of a working fluid is transformed into mechanical energy, in which variations of volume created by the working fluid in a working chamber produce equivalent displacements of the mechanical member transmitting the energy, the dynamic effect of the fluid being of minor importance, and vice versa;
    • "non-positive displacement" means the way the energy of a working fluid is transformed into mechanical energy, by transformation of the energy of the working fluid into kinetic energy, and vice versa;
    • "oscillating-piston machine" means a positive-displacement machine in which a fluid-engaging work-transmitting member oscillates. This definition applies also to engines and pumps;
    • "rotary-piston machine" means a positive-displacement machine in which a fluid-engaging work-transmitting member rotates about a fixed axis or about an axis moving along a circular or similar orbit. This definition applies also to engines and pumps;
    • "rotary piston" means the work-transmitting member of a rotary-piston machine and may be of any suitable form, e.g., like a toothed gear;
    • "cooperating members" means the "oscillating piston" or "rotary piston" and another member, e.g., the working-chamber wall, which assists in the driving or pumping action;
    • "movement of the co-operating members" is to be interpreted as relative, so that one of the "co-operating members" may be stationary, even though reference may be made to its rotational axis, or both may move;
    • "teeth or tooth equivalents" include lobes, projections or abutments;
    • "internal-axis type" means that the rotational axes of the inner and outer co-operating members remain at all times within the outer member, e.g., in a similar manner to that of a pinion meshing with the internal teeth of a ring gear;
    • "free piston" means a piston of which the length of stroke is not defined by any member driven thereby;
    • "cylinders" means positive-displacement working chambers in general. Thus, this term is not restricted to cylinders of circular cross-section;
    • "main shaft" means the shaft which converts reciprocating piston motion into rotary motion or vice versa;
    • "plant" means an engine together with such additional apparatus as is necessary to run the engine. For example, a steam engine plant includes a steam engine and means for generating the steam;
    • "working fluid" means the driven fluid in a pump and the driving fluid in an engine. The working fluid may be in a gaseous state, i.e., compressible, or liquid. In the former case coexistence of two states is possible;
    • "steam" includes condensable vapours in general, and "special vapour" is used when steam is excluded;
    • "reaction type" as applied to non-positive-displacement machines or engines means machines or engines in which pressure/velocity transformation takes place wholly or partly in the rotor. Mmachines or engines with no, or only slight, pressure/velocity transformation in the rotor are called "impulse type".
  3. In this subsection:
  4. For use of this subsection with a good understanding, it is essential to remember, so far as subclasses F01B, F01C, F01D, F03B, and F04B, F04C, F04D, which form its skeleton, are concerned:
    • the principle which resides in their elaboration,
    • the classifying characteristics which they call for, and
    • their complementarity.
      1. Principle

        This concerns essentially the subclasses listed above. Other subclasses, notably those of class F02, which cover better-defined matter, are not considered here.

        Each subclass covers fundamentally a genus of apparatus (engine or pump) and by extension covers equally "machines" of the same kind. Two different subjects, one having a more general character than the other, are thus covered by the same subclass.

        Subclasses F01B, F03B, F04B, beyond the two subjects which they cover, have further a character of generality in relation to other subclasses concerning the different species of apparatus in the genus concerned.

        This generality applies as well for the two subjects dealt with, without these always being in relation to the same subclasses.

        Thus, subclass F03B, in its part dealing with "machines", should be considered as being the general class relating to subclasses F04B, F04C, and in its part dealing with "engines" as being general in relation to subclass F03C.

      2. Characteristics

        The principal classifying characteristic of the subclass is that of genera of apparatus, of which there are three possible:

        Machines; engines; pumps.

        As stated above, "machines" are always associated with one of the other two genera. These main genera are subdivided according to the general principles of operation of the apparatus:

        Positive displacement; non-positive displacement.

        The positive displacement apparatus are further subdivided according to the ways of putting into effect the principle of operation, that is, to the kind of apparatus:

        Simple reciprocating piston; rotary or oscillating piston; other kind.

        Another classifying characteristic is that of the working fluid, in respect of which three kinds of apparatus are possible, namely:

        Liquid and elastic fluid; elastic fluid; liquid.

      3. Complementarity

        This resides in association of pairs of the subclasses listed above, according to the characteristics under consideration in respect of kind of apparatus or working fluid.

        The subclasses concerned with the various principles, characteristics and complementarity are shown in the following table:

It is seen from this table that:

  
LIGHTING; HEATING
 F24
HEATING; RANGES; VENTILATING (protecting plants by heating in gardens, orchards, or forests A01G 13/06; baking ovens and apparatus A21B; cooking devices other than ranges A47J; forging B21J, B21K; specially adapted for vehicles, see the relevant subclasses of classes B60-B64; combustion apparatus in general F23; drying F26B; ovens in general F27; electric heating elements or arrangements H05B)
 F24

Note(s)

In this class, the following terms are used with the meanings indicated:

  • "stove" includes apparatus which may have an open fire, e.g. fireplace;
  • "range" means an apparatus for cooking having elements that perform different cooking operations or cooking and heating operations.

 F24H
FLUID HEATERS, e.g. WATER OR AIR HEATERS, HAVING HEAT-GENERATING MEANS, IN GENERAL (tube furnaces for thermal non-catalytic cracking C10G 9/20; devices, e.g. valves, for venting and aerating enclosures F16K 24/00; steam traps or like apparatus F16T; steam generation F22; combustion apparatus F23; domestic stoves or ranges F24B, F24C; domestic- or space-heating systems F24D; furnaces, kilns, ovens, retorts F27; heat-exchangers F28; electric heating elements or arrangements H05B)
 F24H

Note(s)

  1. The distinguishing feature of the air heaters covered by this subclass is that the heat is predominantly released to the air by convection, mostly by forced circulation of the air. The domestic stoves or ranges covered by subclass F24B, F24C may also be fired or electric air heaters but they release their heat to a considerable extent by radiation and only to some extent by natural convention. [3]
  2. In this subclass, the following terms or expressions are used with the meanings indicated:
    • "water" includes other liquids and means always the liquid to be heated; [3]
    • "air" includes other gases or gas mixtures and means always the gas to be heated; [3]
    • "furnace tubes" means tubes inside the heater wherein combustion is performed; [3]
    • "fire tubes" means tubes inside the heater through which flue-gases flow from a combustion chamber located outside the tubes; [3]
    • "heater" means apparatus including both heat generating means and means for transferring the generated heat to water or air. [3]
  3. All storage heaters are classified in group F24H 7/00[3]
 F24H
Subclass index
WATER HEATERS 1/00
AIR HEATERS; STORAGE HEATERS 3/00; 7/00
FLUID HEATERS USING HEAT PUMPS 4/00
COMBINATIONS OF WATER AND AIR HEATERS 6/00
FLUID HEATERS FOR EXTRACTING LATENT HEAT FROM FLUE GASES 8/00
DETAILS 9/00
 F24H 1/00
Water heaters having heat generating means, e.g. boiler, flow-heater, water-storage heater (F24H 7/00, F24H 8/00 take precedence; details F24H 9/00; steam boilers F22B; domestic stoves or ranges with additional provisions for heating water F24B 9/00, F24C 13/00)  [5]
 F24H 1/06
·  Portable or mobile, e.g. collapsible
 F24H 1/08
·  Packaged or self-contained boilers, i.e. water heaters with control devices and pump in a single unit
 F24H 1/10
·  Continuous-flow heaters, i.e. heaters in which heat is generated only while the water is flowing, e.g. with direct contact of the water with the heating medium (F24H 1/50 takes precedence)  [5]
 F24H 1/12
·  ·  in which the water is kept separate from the heating medium
 F24H 1/14
·  ·  ·  by tubes, e.g. bent in serpentine form
 F24H 1/16
·  ·  ·  ·  helically or spirally coiled
 F24H 1/18
·  Water-storage heaters (F24H 1/50 takes precedence; combined with water-heating stoves for central heating F24H 1/22)  [5]
 F24H 1/20
·  ·  with immersed heating elements, e.g. electric elements or furnace tubes
 F24H 1/22
·  Water heaters other than continuous-flow or water-storage heaters, e.g. water heaters for central heating (F24H 1/50 takes precedence)  [5]
 F24H 1/24
·  ·  with water mantle surrounding the combustion chamber or chambers (F24H 1/40, F24H 1/44 take precedence)  [3]
 F24H 1/26
·  ·  ·  the water mantle forming an integral body
 F24H 1/28
·  ·  ·  ·  including one or more furnace or fire tubes
 F24H 1/30
·  ·  ·  the water mantle being built-up from sections
 F24H 1/32
·  ·  ·  ·  with vertical sections arranged side by side
 F24H 1/34
·  ·  with water chamber arranged adjacent to the combustion chamber or chambers, e.g. above or at side (F24H 1/24, F24H 1/44 take precedence)
 F24H 1/36
·  ·  ·  the water chamber including one or more fire tubes
 F24H 1/38
·  ·  with water contained in separate elements, e.g. radiator-type element (F24H 1/40, F24H 1/44 take precedence)
 F24H 1/40
·  ·  with water tube or tubes (F24H 1/44 takes precedence)
 F24H 1/41
·  ·  ·  in serpentine form  [3]
 F24H 1/43
·  ·  ·  helically or spirally coiled  [3]
 F24H 1/44
·  ·  with combinations of two or more of the types covered by groups F24H 1/24-F24H 1/40
 F24H 1/46
·  Water heaters having plural combustion chambers  [2,5]
 F24H 1/48
·  Water heaters for central heating incorporating heaters for domestic water  [5]
 F24H 1/50
·  ·  incorporating domestic water tanks  [5]
 F24H 1/52
·  ·  incorporating heat exchangers for domestic water (F24H 1/50 takes precedence)  [5]
 F24H 3/00
Air heaters having heat generating means (F24H 7/00, F24H 8/00 take precedence; details F24H 9/00; domestic stoves or ranges with additional provisions for convection heating of air F24B, F24C)  [5]
 F24H 3/02
·  with forced circulation (F24H 3/12 takes precedence)
 F24H 3/04
·  ·  the air being in direct contact with the heating medium, e.g. electric heating element
 F24H 3/06
·  ·  the air being kept separate from the heating medium, e.g. using forced circulation of air over radiators
 F24H 3/08
·  ·  ·  by tubes
 F24H 3/10
·  ·  ·  by plates
 F24H 3/12
·  with additional heating arrangements
 F24H 4/00
Fluid heaters using heat pumps  [5]
 F24H 4/02
·  Liquid heaters  [5]
 F24H 4/04
·  ·  Storage heaters  [5]
 F24H 4/06
·  Gas heaters  [5]
 F24H 6/00
Combined water and air heaters (F24H 8/00 takes precedence)  [5]
 F24H 7/00
Storage heaters, i.e. heaters in which the energy is stored as heat in masses for subsequent release (domestic stoves or ranges with additional heat storage masses F24B 1/24, F24C 15/34; materials for storage masses, see the relevant subclasses)
 F24H 7/02
·  the released heat being conveyed to a transfer fluid, e.g. air, water
 F24H 7/04
·  ·  with forced circulation of the transfer fluid
 F24H 7/06
·  the released heat being radiated
 F24H 8/00
Fluid heaters having heat-generating means specially adapted for extracting latent heat from flue gases by means of condensation  [5]
 F24H 9/00
Details
 F24H 9/02
·  Casings; Cover lids; Ornamental panels
 F24H 9/06
·  Arrangement of mountings or supports
 F24H 9/12
·  Connecting heaters to circulation pipes (pipe joints in general F16L)
 F24H 9/14
·  Connecting different sections, e.g. in water heaters (in radiators F28F 9/26)
 F24H 9/16
·  Arrangements for water drainage (valves for drainage F16K, e.g. F16K 21/00; in pipes or pipe systems in general F16L 55/00; in domestic-or space-heating systems F24D 19/08)
 F24H 9/18
·  Arrangement or mounting of grates, burners, or heating elements (burners F23D; grates F23H; electric heating elements H05B)
 F24H 9/20
·  Arrangement or mounting of control or safety devices (control valves F16K; safety devices for burners F23D; combustion control devices F23N; of systems comprising a heater, see the relevant subclasses, e.g. of control heating systems F24D 19/10; automatic switching for electric heating apparatus H05B 1/02)