US3583453A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screen-changing apparatus for extruders
Assignee: Windmoeller and Hoelscher KG
•
Filing: 1969-02-25
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Granted: 1971-06-08
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Expires: 1989-02-25
Abstract
Abstract A slider is provided with two detachable sets of screens and is displaceable by a power-operated displacing device in a double slide track disposed at the discharge end of the extruder cylinder. The double slide track consists of two housing halves, which are relatively movable in the feeding direction of the material and on which engaging surfaces of the slider bear in both end positions thereof. The displacing device has an output member that is connected to the slider. An abutment cooperates with the displacing device and is movable relative to the double slide track in the direction of pressure and firmly connected to a clamping device for clamping the housing halves against the slider. Prestressed spring elements are provided between the clamping device and the housing halves and hold the clamping device in an ineffective position during the displacement of the slider. The spring force of said spring elements is smaller than the pressure exerted by the displacing device on the abutment when the slider has reached its end position. The initial stress of said spring elements exceeds the force required to displace the slider.
Inventors
- 👤 Hartmut Upmeier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:22
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/69; B29C48/691; B29C48/6912; B29C48/254; B29C48/03
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
199 words
A screen-changing apparatus for extruders for processing thermoplastic material; said apparatus comprising a slider which is provided with two detachable sets of screens and is displaceable by a power-operated displacing device in a double slide track disposed at the discharge end of an extruder cylinder, said double slide track comprising two housing halves, which are relatively movable in the feeding direction of the material and on which engaging surfaces of the slider bear in both end positions thereof, said displacing device having an output member that is connected to the slider, an abutment cooperates with the displacing device and is movable relative to the double slide track in the direction of pressure and firmly connected to a clamping device for clamping the housing halves against the slider, prestressed spring elements are provided between the clamping device and the housing halves and hold the clamping device in an ineffective position during the displacement of the slider, the spring force of said spring elements being smaller than the pressure exerted by the displacing device on the abutment when the slider has reached its end position, and the initial stress of said spring elements exceeds the force required to displace the slider.
Claim 2
Dependent Claim
199 words
A screen-changing apparatus for extruders for processing thermoplastic material; said apparatus comprising a slider which is provided with two detachable sets of screens and is displaceable by a power-operated displacing device in a double slide track disposed at the discharge end of an extruder cylinder, said double slide track comprising two housing halves, which are relatively movable in the feeding direction of the material and on which engaging surfaces of the slider bear in both end positions thereof, said displacing device having an output member that is connected to the slider, an abutment cooperates with the displacing device and is movable relative to the double slide track in the direction of pressure and firmly connected to a clamping device for clamping the housing halves against the slider, prestressed spring elements are provided between the clamping device and the housing halves and hold the clamping device in an ineffective position during the displacement of the slider, the spring force of said spring elements being smaller than the pressure exerted by the displacing device on the abutment when the slider has reached its end position, and the initial stress of said spring elements exceeds the force required to displace the slider.
Claim 3
Dependent Claim
58 words
A screen-changing apparatus according to claim 1, wherein the clamping device comprises wedge clamps, which are connected to the abutment for the displacing device and embrace the housing halves, and which comprise at least one obtuse-angled double wedge on at least one pressure surface and complementary double wedge surfaces on the complementary reaction surface of the housing halves.
Claim 4
Dependent Claim
130 words
A screen-changing apparatus according to claim 2, wherein each of the spring elements which hold the clamping device in an ineffective position during the displacement of the slider consists of a set of prestressed disc springs, which are provided in spring sleeves, which are attached to the wedge clamps and extend into openings of the housing half but are shorter than the opening, and each set of disc springs are adapted to bear at each end by a thrust washer on an end flange of the spring sleeve and a pressure member, which extends through the central opening of the end flange and bears on the end faces of the housing halves, said pressure member being longer in the direction of pressure than the end flange of the spring sleeve.
Claim 5
Dependent Claim
48 words
A screen-changing apparatus according to claim 1, wherein pressure plates are connected by a spring clamp and engageable with both sides of that portion of the slider which extends out of the guide housing to hold in position the cleaned set of screens not used at a time.
Claim 6
Dependent Claim
28 words
A screen-changing apparatus according to claim 4, wherein the pressure plates are provided with flat heaters for heating that portion of the slider which protrudes from the Housing.
References Cited (Backward Citations)
US2661497A
Cited
US3145746A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-07 | 1974-12-07 | 1975-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-07 | 1978-12-07 | 1979-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-07 | 1982-12-07 | 1983-06-08 | $7700.00 | Window Closed / Lapsed |