CPC Definition - Subclass F04C
This place covers:
Pumps with rotary or oscillating pistons for liquids, for elastic fluids, or for combination of liquid and elastic fluid.
Positive displacement machines, i.e. devices which could be equally an engine or pump, with rotary or oscillating pistons for liquids only.
Related subclasses F01C and F04C cover the same type of apparatus using rotary or oscillating pistons for positive displacement. The distinguishing characteristic used for classifying the machines, i.e. devices which could be equally be an engine or pump, is the working fluid used. Machines with rotary or oscillating pistons for working fluids containing elastic fluids, e.g. a combination of liquids and elastic fluids are classified in F01C. If only liquid is used as working fluid for these machines with rotary or oscillating pistons they are classified in F04C.
Classification is in F03C when the working fluid is a liquid but the machine is specifically an engine with reciprocating pistons or rotary or oscillating pistons.
Devices with rotary or oscillating pistons that are only pumps, i.e. cannot be used as engines, are classified in F04C, irrespective of the working fluid. F04B covers machines or pumps with reciprocating pistons, or other kinds of positive displacement mechanisms with the exception of rotary or oscillating piston type machines or pumps.
Subject matter like cyclically operating valves, lubricating or cooling are classified in subclasses F01L, F01M, F01P irrespective of their stated application, unless their novel and non-obvious features are peculiar to their application, in which case they are classified only in the relevant subclass of F04. The subclasses F01L, F01M, F01P do not cover pump or machine features per se.
This place does not cover:
Attention is drawn to the following places, which may be of interest for search:
Rotary-piston or oscillating piston engines for liquids and elastic fluids | |
Cyclically operating valves for machines or engines | |
Lubrication of machines or engines in general | |
Gas-flow silencer or exhaust apparatus for machines or engines in general | |
Cooling of machines or engines in general | |
Combustion engines with pumps for charging | |
Fluid pressure actuators | |
Rotary fluid gearing using pumps and motors of the volumetric type for conveying rotary motion | |
Sealing in general | |
Means for thermal insulation in general | |
Refrigeration machines, plants or systems |
As a general rule a complete classification will contain at least one class specifying the type of pump concerned, combined with at least one class out of the control group F04C 14/00 or F04C 28/00, or of the sealing group F04C 27/00 or of the accessory group F04C 15/00 or F04C 29/00.
In cases were a control or a "Details, component, parts, or accessories" has to be classified which can be used in a number of different types of pumps which would be covered by different groups, the type of pump considered in the document should be classified by using the corresponding Indexing Code.
The Indexing Code F05C is used to classify materials and material properties.
In this place, the following terms or expressions are used with the meaning indicated:
Pump | means a device for continuously raising, forcing, compressing, or exhausting fluid by mechanical means |
Machine | means a device that could equally be both 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 pumps | pumps using pistons or other mechanical members to displace a working fluid in a working chamber, the dynamic effect on the fluid being of minor importance |
Positive displacement engines | 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 movement of mechanical members, e.g. pistons transmitting the energy, the dynamic effect of the fluid being of minor importance |
Oscillating piston machine | means a positive-displacement machine in which a fluid-engaging, work-transmitting member oscillates, e.g. a vane piston swinging back and forth about a fixed axis |
Reciprocating piston | means a fluid-engaging, work-transmitting member of an reciprocating-piston type machine or pump that slides alternately back and forth usually along a straight line or path |
Rotary piston | means a fluid engaging, work-transmitting member of a rotary-piston machine or pump that can completely rotate about a fixed axis or about an axis moving along a circular or similar orbit when operating, e.g. rotor having vanes or teeth |
Rotary piston machine | means a positive-displacement machine in which a liquid-engaging, work-transmitting member rotates about a fixed axis or about an axis moving along a circular or similar orbit, e.g. machine with a rotor having vanes or teeth |
Cooperating members | means the "oscillating piston" or "rotary piston" and another member, e.g., the working-chamber wall, which assists in the pumping action or machine's action |
Movement of the cooperating members | is to be interpreted as relative, so that one of the "cooperating 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 |
Working fluid | means the driven fluid in a pump or driving or driven liquid in a machine. The working fluid can be in a compressible, gaseous state, e.g. steam, called elastic fluid, a liquid state, or a state where there is coexistence of elastic fluid and liquid state |
This place does not cover:
Rotary-piston machines or pumps with non-parallel axes of co-operating members | |
Rotary-piston machines or pumps with the working-chamber walls at least partly resiliently deformable | |
Rotary-piston machines or pumps with fluid ring or the like | |
Rotary-piston machines or pumps specially adapted for elastic fluids | |
Rotary-piston machines or pumps in which the working-fluid is exclusively displaced by, or exclusively displaces, one or more reciprocating pistons |
Attention is drawn to the following places, which may be of interest for search:
Gear teeth manufacturing by metal processing | |
Extruders in plastic moulding |
This place does not cover:
Non intermeshing-engagement type machines |
If the carter is not the core topic, it is highly desirable to add the Indexing Code F04C 2240/10 or F04C 2240/30.
Attention is drawn to the following places, which may be of interest for search:
Details of the mould |
This place covers:
Rotary-piston machines or pumps, with non-parallel axes of movement of co-operating members, e.g. of screw type
This place does not cover:
Rotary screw type piston pumps with parallel axes | |
Rotary-piston pumps with the working-chamber walls at least partly resiliently deformable | |
Rotary-piston pumps with non-parallel axes of movement of co-operating members specially adapted for elastic fluids |
This place does not cover:
Such pumps specially adapted for elastic fluids | |
Peristaltic pumps |
This place covers:
Rotary-piston machines or pumps in which the rotary-piston is sealed by a mass of liquid rotating inside the housing.
This place does not cover:
Such pumps specially adapted for elastic fluids |
This place covers:
Rotary-piston machines or pumps in which the rotary-piston moves back and forth inside the working chamber.
This place does not cover:
Rotary-piston pumps with coaxially mounted members having continuously-changing circumferential spacing between them | |
Such pumps specially adapted for elastic fluids |
This place does not cover:
Rotary-piston machines or pumps with non-parallel axes of movement between co-operating members | |
Rotary-piston machines or pumps in which the working fluid is compressed in a flexible chamber |
This place covers:
Combinations of two or more machines or pumps, each being of rotary-piston or oscillating-piston type, such as multistage and parallel operating machines; Pumping installations
This place does not cover:
Combinations of such pumps specially adapted for elastic fluids | |
Combination of engines with pumps or compressors driven thereby |
Attention is drawn to the following places, which may be of interest for search:
Fluid gearing |
F04C 13/00 takes precedence.
This place does not cover:
Of such pumps specially adapted for elastic fluids | |
Combination of engines with pumps or compressors driven thereby |
Documents classified here should have a main class elsewhere.
This place does not cover:
Prevention of deposits in the pump |
This place covers:
Drawing well fluid out of a well with the adaptation for being below the earth's surface, and also pumps working in submersed conditions for other use.
Attention is drawn to the following places, which may be of interest for search:
Earth drilling |
This place covers:
Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations.
This place does not cover:
Of pumps or pumping installations specially adapted for elastic fluids |
Documents classified here should have a main class elsewhere.
This place covers:
Measures or means for stopping, starting or idling a compressor or a pump; measures taken as a consequence or preceding starting, stopping or idling favouring the action, e.g. having reduced side sealing pressure at start.
This place covers:
Rotary-piston machines or pumps controlled by varying the volume of the working chamber also including those where the underlined expression is construed as changing the stroke ("stroke" as relative displacement between cooperating members defining the size of the working chamber as in reciprocating engines).
This place does not cover:
By changing the positions of inlet or outlet openings |
This place does not cover:
Internal gear pumps with variable eccentricity (i.e. variable in direction and not in quantity)(no change of volume but only relative displacement of the working chamber to the inlet and outlet openings). |
This place covers:
Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C 2/00 - F04C 14/00.
This place does not cover:
Of pumps specially adapted for elastic fluids |
This place does not cover:
Silencing for compressors | |
Bearings | |
Interstice adjustment other than by fluid pressure |
This place does not cover:
Seals for sealing such spaces |
This place does not cover:
Silencing for compressors | |
Vibration control |
Attention is drawn to the following places, which may be of interest for search:
Oldham couplings |
Attention is drawn to the following places, which may be of interest for search:
Rotor/shaft keyed connections | |
Shaft sleeves | |
Couplings for rigidly connecting two coaxial shafts or other movable machine elements, with clamping hub or with hub and longitudinal key |
This place does not cover:
Rotary-piston pumps for liquids or both liquids and elastic fluids | |
Rotary-piston pumps with fluid ring or the like | |
Rotary-piston pumps in which the working-fluid is exclusively displaced by one or more reciprocating pistons |
Attention is drawn to the following places, which may be of interest for search:
Gear teeth manufacturing by metal processing |
This place covers:
Outer member cooperating with the toothed wheels; casing
This place does not cover:
Non intermeshing-engagement type pumps |
If the carter is not the core topic, it is highly desirable to add the Indexing Code F04C 2240/10 or F04C 2240/30.
This place covers:
Rotary-piston pumps in which the rotary-piston is sealed by a mass of liquid rotating inside the housing.
This place covers:
Rotary-piston pumps in which the rotary-piston moves back and forth inside the working chamber.
This place does not cover:
Rotary-piston pumps with non-parallel axes of movement between co-operating members | |
Rotary-piston pumps in which the working fluid is compressed in a flexible chamber |
This place covers:
Combinations of two or more pumps, each being of rotary-piston or oscillating-piston type, specially adapted for elastic fluids; Pumping installations specially adapted for elastic fluids; Multi-stage pumps operating in parallel or in series specially adapted for elastic fluids.
This place does not cover:
Combination of engines with pumps or compressors driven thereby |
F04C 25/00 takes precedence.
This place covers:
Adaptations of pumps for special use of pumps for elastic fluids.
This place does not cover:
Combination of engines with pumps or compressors driven thereby |
Documents classified here should have a main class elsewhere.
This place covers:
Pumps adapted for working at pressures below atmospheric pressure.
This place does not cover:
Sealing arrangements | |
Silencing |
Attention is drawn to the following places, which may be of interest for search:
Discharge tubes with vacuum locks | |
Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof |
This place covers:
Any seal construction or mode not provided by the groups, e.g. labyrinth.
This place covers:
Especially scroll compressors where the axial sealing force is cancelled for capacity control purposes (e.g. forming an axial gap between scroll bodies).
When capacity control is concerned, it is highly desirable to add the Indexing Code F04C 28/265.
This place covers:
Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids.
Documents classified here should have a main class elsewhere.
This place covers:
Measures or means for stopping, starting or idling a compressor or pump; measures taken as a consequence or preceding starting, stopping or idling favouring the action, e.g. having reduced side sealing pressure at start.
This place does not cover:
Rotary-Piston pumps where a sliding valve controls an opening or port of non uniform section progressively (or a multiplicity of holes, passages forming as a whole an inlet or outlet port of a machine, pump). |
In this place, the following terms or expressions are used with the meaning indicated:
Lift valve | valve with an ON-OFF action, i.e. opening or closing a passage in one movement |
This place covers:
Rotary-piston pumps controlled by varying the volume of the working chamber also including those where the underlined expression is construed as changing the stroke ("stroke" as relative displacement between cooperating members defining the size of the working chamber as in reciprocating engines).
This place does not cover:
By changing the positions of inlet or outlet openings |
Documents classified here should have a main class elsewhere.
This place does not cover:
Silencing | |
Vibration control |
Attention is drawn to the following places, which may be of interest for search:
Oldham couplings |
Attention is drawn to the following places, which may be of interest for search:
Rotor/shaft keyed connections | |
Shaft sleeves | |
Couplings for rigidly connecting two coaxial shafts or other movable machine elements, with clamping hub or with hub and longitudinal key |
This place does not cover:
Prevention of deposits in the pump |
Attention is drawn to the following places, which may be of interest for search:
Heating, cooling of machines or engines in general | |
Heat insulation in general |
Attention is drawn to the following places, which may be of interest for search:
Gas-flow silencers or exhaust apparatus for machines or engines in general |
This place covers:
Additional information regarding the function, the nature and the properties of fluids inside the machine.
This place covers:
Additional information regarding the use of the machine.
This place covers:
Additional information regarding the manufacturing process of the machine, including surface treatments, repair, assembly and disassembly methods.
This place covers:
Additional information regarding machine parts.
This place covers:
Additional information regarding forms and dimensions of machine parts.
This place covers:
Additional information regarding parameters used to control or monitor a rotary-piston machine.