US3640236A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thread retainer for sewing machines
Assignee: Duerkoppwerke GmbH
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Filing: 1970-07-01
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Granted: 1972-02-08
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Expires: 1990-07-01
Abstract
Abstract A double-lockstitch sewing machine, provided with a threadcutting mechanism, has a thread retainer for supplying a predetermined thread length of upper thread at the conclusion of a stitching operation and as a preliminary to a subsequent stitching operation. The retaining arrangement includes a thread brake which is released at the end of the stitching operation and an eye for drawing the released thread from a spool or other supply to provide the desired length.
Inventors
- 👤 Karl Nicolay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:58
CPC Classifications
D; D05; D05B; D05B47/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
149 words
A thread-control mechanism for a sewing machine having an arm overhanging a stitch plate, a needle reciprocable on said arm, a reciprocable thread-feed member reciprocable on said arm and feed means for advancing a sewing thread in succession through said thread-feed member and said needle, said thread-control mechanism comprising a thread brake on said arm forming part of said feed means and engageable with a sewing thread fed through said thread feed member and needle for retarding passage thereof to said needle, a brake-control lever engageable with said thread brake and swingably mounted on said arm for releasing the thread, a loop-forming lever swingably mounted on said arm and forming part of said feed means for engaging thread beTween said thread-feed member and said needle for forming a thread loop, and actuating means forming part of said feed means for sequentially operating said brake-control lever and said loop-forming lever.
Claim 2
Dependent Claim
149 words
A thread-control mechanism for a sewing machine having an arm overhanging a stitch plate, a needle reciprocable on said arm, a reciprocable thread-feed member reciprocable on said arm and feed means for advancing a sewing thread in succession through said thread-feed member and said needle, said thread-control mechanism comprising a thread brake on said arm forming part of said feed means and engageable with a sewing thread fed through said thread feed member and needle for retarding passage thereof to said needle, a brake-control lever engageable with said thread brake and swingably mounted on said arm for releasing the thread, a loop-forming lever swingably mounted on said arm and forming part of said feed means for engaging thread beTween said thread-feed member and said needle for forming a thread loop, and actuating means forming part of said feed means for sequentially operating said brake-control lever and said loop-forming lever.
Claim 3
Dependent Claim
37 words
The mechanism defined in claim 1 wherein said sewing machine has an upper thread cutter for severing said thread, said actuating means being operatively connected with said cutter for operating same upon the formation of said loop.
Claim 4
Dependent Claim
20 words
The mechanism defined in claim 2, further comprising means for adjusting the stroke of at least one of said levers.
Claim 5
Dependent Claim
25 words
The mechanism defined in claim 2, further comprising spring means yieldably resistant to displacement of at least one of said levers by said actuating means.
Claim 6
Dependent Claim
16 words
The mechanism defined in claim 4 wherein said actuating means includes at least one pneumatic cylinder.
Claim 7
Dependent Claim
15 words
The mechanism defined in claim 4 wherein said actuating means includes at least one electromagnet.
Claim 8
Dependent Claim
31 words
The mechanism defined in claim 4 wherein said actuating means includes a bar mounted in said arm and shiftable longitudinally thereof and lost-motion means connecting said bar with said loop-forming lever.
Claim 9
Dependent Claim
25 words
The mechanism defined in claim 7 wherein said loop-forming lever is provided with an eccentric fulcrum rotatable to shift the fulcrum axis on said arm.
Claim 10
Dependent Claim
37 words
The mechanism defined in claim 8, further comprising a pair of vertically spaced fixed thread-guiding eyes between said thread-feed member and said needle, said loop-forming lever being provided with a movable eye received between said fixed arms.
Claim 11
Dependent Claim
20 words
The mechanism defined in claim 9, wherein said thread brake has a spring-biased disk, said brake-control lever engaging said disk.
References Cited (Backward Citations)
US1048442A
Cited
US1273157A
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US2584013A
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US2976831A
Cited
US2925058A
Cited
DE1128726B
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |