US4040607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of building up pressure by multi-shaft screw extruders
Assignee: Bayer AG
•
Filing: 1975-09-22
•
Granted: 1977-08-09
•
Expires: 1995-09-22
Abstract
Abstract This invention relates to multi-shaft screw extruders in which the screw shafts are arranged to intermesh in pairs and rotate pairwise in the same sense, each shaft of a pair having at least one double threaded or triple threaded pressure build-up section corresponding to that of the other shaft. This invention also relates to a method of using such an extruder to build up pressure within a material with a minimum pressure build-up section and a minimum power input. The extruder and its method of operation are characterized by the fact that at least a portion of the pressure build-up section satisfies ##EQU1## WHEREIN T IS THE SCREW PITCH, D IS THE INTERNAL DIAMETER OF THE HOUSING, Q IS THE VOLUMETRIC THROUGHPUT OF MATERIAL OF A SCREW PAIR AND N IS THE SPEED OF ROTATION OF THE SCREW SHAFTS AND: ##EQU2## WHEREIN IN TRIPLE THREAD PRESSURE BUILD-UP SECTIONS A = 0.1082; a = 15.316; b = 69.111; And c = 261.85 And in double thread pressure build-up sections A = 0.206; a = 8.8212; b = 18.414; And c = 31.668.
Inventors
- 👤 Martin Ullrich
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:46
CPC Classifications
F; F04; F04C; F04C2/00; F04C2/08; F04C2/12; F04C2/14; F04C2/16; B; B29; B29B; B29B7/00; B29B7/30; B29B7/34; B29B7/38; B29B7/46; B29B7/48; B29B7/485; B29C; B29C48/00; B29C48/25; B29C48/251; B29C48/2517; B29C48/36; B29C48/395; B29C48/40; B29C48/402; F01; F01C; F01C1/00; F01C1/08; F01C1/12; F01C1/14; F01C1/16; B29C48/03
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
135 words
A method of building up pressure within a material comprising using a multi-shaft screw extruder having a plurality of screw shafts arranged to intermesh in pairs and to rotate pairwise in the same sense, in which each screw shaft of a pair has a double thread pressure buildup section corresponding to that of the other screw shaft, wherein the pressure buildup sections have at least in part a ratio of screw pitch t to the internal diameter of the housing d within the range given by the following relationships: ##EQU10## where q is the volumetric throughput of material of a screw pair, n is the speed of rotation of the screw shafts and h is the screw thread depth, and: ##EQU11## wherein A = 0.206; a = 8.8212; b = 18.414; and c = 31.668
Claim 2
Independent Claim
135 words
A method of building up pressure within a material comprising using a multi-shaft screw extruder having a plurality of screw shafts arranged to intermesh in pairs and to rotate pairwise in the same sense, in which each screw shaft of a pair has a double thread pressure buildup section corresponding to that of the other screw shaft, wherein the pressure buildup sections have at least in part a ratio of screw pitch t to the internal diameter of the housing d within the range given by the following relationships: ##EQU10## where q is the volumetric throughput of material of a screw pair, n is the speed of rotation of the screw shafts and h is the screw thread depth, and: ##EQU11## wherein A = 0.206; a = 8.8212; b = 18.414; and c = 31.668
Claim 3
Independent Claim
133 words
A method of building up pressure within a material comprising using a multi-shaft screw extruder having a plurality of screw shafts arranged to intermesh in pairs and to rotate pairwise in the same sense, in which each screw shaft of a pair has a triple thread pressure buildup section corresponding to that of the other screw shaft, wherein the pressure buildup sections have at least in part, a ratio of screw pitch t to internal diameter of housing d within the range given by the following relationships: ##EQU12## where q is the volumetric throughput of material of a screw pair, n is the speed of rotation of the screw shafts, and h is the screw thread depth, and: ##EQU13## wherein A = 0.1082; a = 15.316; b = 69.111; and c = 261.85.
Claim 4
Independent Claim
133 words
A method of building up pressure within a material comprising using a multi-shaft screw extruder having a plurality of screw shafts arranged to intermesh in pairs and to rotate pairwise in the same sense, in which each screw shaft of a pair has a triple thread pressure buildup section corresponding to that of the other screw shaft, wherein the pressure buildup sections have at least in part, a ratio of screw pitch t to internal diameter of housing d within the range given by the following relationships: ##EQU12## where q is the volumetric throughput of material of a screw pair, n is the speed of rotation of the screw shafts, and h is the screw thread depth, and: ##EQU13## wherein A = 0.1082; a = 15.316; b = 69.111; and c = 261.85.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-08 | 1981-02-07 | 1981-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-08 | 1985-02-07 | 1985-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-08 | 1989-02-07 | 1989-08-09 | $7700.00 | Window Closed / Lapsed |