CPC Subgroup
B29C 48/505 Screws
Full Title
Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor (extrusion blow-moulding B29C49/04) > Component parts, details or accessories; Auxiliary operations > Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die > Details of extruders > Screws
20 direct subcodes
Child Classifications
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- B29C 48/51 with internal flow passages, e.g. for molten material
- B29C 48/52 with an outer diameter varying along the longitudinal axis, e.g. for obtaining different thread clearance
- B29C 48/53 having a varying channel depth, e.g. varying the diameter of the longitudinal screw trunk
- B29C 48/535 with thread pitch varying along the longitudinal axis
- B29C 48/54 with additional forward-feeding elements
- B29C 48/55 having reverse-feeding elements
- B29C 48/56 having grooves or cavities other than the thread or the channel
- B29C 48/565 having projections other than the thread, e.g. pins
- B29C 48/57 provided with kneading disc-like elements, e.g. with oval-shaped elements
- B29C 48/575 provided with elements of a generally circular cross-section for shearing the melt, i.e. shear-ring elements
- B29C 48/58 provided with seal ring elements, i.e. elements of generally circular and tapered shape for preventing the back flow of the melt
- B29C 48/585 provided with gears interacting with the flow
- B29C 48/59 characterised by details of the thread, i.e. the shape of a single thread of the material-feeding screw
- B29C 48/62 characterised by the shape of the thread channel, e.g. U-shaped
- B29C 48/625 characterised by the ratio of the threaded length of the screw to its outside diameter [L/D ratio]
- B29C 48/63 having sections without mixing elements or threads, i.e. having cylinder shaped sections
- B29C 48/635 Eccentrically rotating screws; Screws revolving around an axis other than their central axis
- B29C 48/64 Screws with two or more threads
- B29C 48/67 having incorporated mixing devices not provided for in groups B29C48/52 - B29C48/66
Top Applicants
Top 10 applicants by patent filingsfor class B29, 2013–2023, worldwide · Source: EPO PATSTAT
- HEWLETT-PACKARD DEVELOPMENT COMPANY US 4,167
- BOEING COMPANY US 3,701
- COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN FR 2,554
- 3M INNOVATIVE PROPERTIES COMPANY (MINNESOTA MINING AND MANUFACTURING INNOVATIVE PROPERTIES COMPANY) US 2,240
- TORAY INDUSTRIES JP 2,133
- GE (GENERAL ELECTRIC COMPANY) US 2,069
- BASF (BADISCHE ANILIN & SODA FABRIK) DE 2,028
- LG CHEM KR 1,962
- DOW GLOBAL TECHNOLOGIES US 1,896
- CONTINENTAL REIFEN DE 1,725