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DIFF Subclass Not Allocatable
F04C

ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS

Introduced: September 1968

Description

F04C covers rotary-piston and oscillating-piston positive-displacement machines and pumps designed to handle liquids. These devices employ rotating or reciprocating pistons to achieve precise volumetric flow control, making them suitable for applications requiring constant displacement per cycle independent of pressure. The classification encompasses gear pumps, vane pumps, screw pumps, and similar designs where mechanical action directly displaces fixed liquid volumes, excluding reciprocating piston machines with linear motion (covered under F04B) and centrifugal or dynamic pumps.

Title

Titles differ between systems:

IPC: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS

CPC: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS

Full Title

Full titles differ between systems:

IPC:

ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS

CPC:

ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS

Additional Content IPC

Glossary

Pump Pumps means a device for continuously raising, forcing, compressing, or exhausting fluid by mechanical means Machine machines 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 oscillating piston machines 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 reciprocating pistons 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 rotary pistons 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 working fluids 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

Limiting references

Positive displacement machines for liquids, or pumps in which the working-fluid is displaced by one or more reciprocating pistons or by flexible working members

Of 24 combined children, 17 exist in both systems.

7 codes are CPC-only extensions.

Note: 7 CPC extensions are marked as secondary classification only.

13 shared codes have differing titles between IPC and CPC.

Child Classifications

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Top Applicants

Top Applicants (IPC)

Class F04,2013–2023, worldwide · Source: EPO PATSTAT

  1. GREE ELECTRIC APPLIANCES 5,351
  2. LG ELECTRONICS KR 3,502
  3. ROBERT BOSCH DE 3,011
  4. MIDEA 2,258
  5. MITSUBISHI ELECTRIC CORPORATION JP 1,663
  6. ZHUHAI LANDA COMPRESSOR COMPANY 1,639
  7. GREE ELECTRIC APPLIANCES, INC.OF ZHUHAI 1,573
  8. ZHUHAI GREE ENERGY-SAVING REFRIGERATION TECHNOLOGY RESEARCH CENTER COMPANY 1,536
  9. TOYOTA INDUSTRIES CORPORATION 1,347
  10. DAIKIN INDUSTRIES 1,325

Top Applicants (CPC)

Class F04,2013–2023, worldwide · Source: EPO PATSTAT

  1. LG ELECTRONICS KR 3,855
  2. ROBERT BOSCH DE 3,549
  3. GREE ELECTRIC APPLIANCES 2,273
  4. GE (GENERAL ELECTRIC COMPANY) US 2,126
  5. MITSUBISHI ELECTRIC CORPORATION JP 1,881
  6. UNITED TECHNOLOGIES CORPORATION (UTC) US 1,866
  7. SAFRAN AIRCRAFT ENGINES FR 1,499
  8. MITSUBISHI HEAVY INDUSTRIES JP 1,258
  9. TOYOTA INDUSTRIES CORPORATION JP 1,247
  10. ATLAS COPCO AIRPOWER BE 1,168