US3857346A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cutting implement for flat-bed sewing machine
Assignee: Individual
•
Filing: 1974-04-15
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Granted: 1974-12-31
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Expires: 1994-04-15
Abstract
Abstract A sewing machine, used for stitching slide fasteners to garments or other pieces of fabric, has a fixed cutter blade spacedly positioned above the machine bed downstream of a pair of stitching needles and a coacting movable cutter blade carried on a vertically reciprocable slider normally withdrawn below the bed surface. The slider, upon being elevated during the cutting step, intercepts an overlying fastener section and clamps it against a spring-loaded shoe overhanging the bed. The clamped section, immediately after being severed from an adjoining section, is contacted by a welding tool fusing some of its links into a bottom stop.
Inventors
- 👤 Negro R Dal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:02
CPC Classifications
D; D05; D05B; D05B81/00; D05B23/00; Y; Y10; Y10T; Y10T156/00; Y10T156/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
176 words
In a sewing machine for slide fasteners comprising a flat bed provided with a gap and a pair of parallel needles aligned with said gap for straddling two interlinked slide-fastener halves while stitching same onto a workpiece moving along said bed, the combination therewith of: a fixed cutter blade spacedly disposed above said gap downstream of said needles; a movable cutter blade confronting said fixed blade in operative alignment therewith; a support for said movable blade normally withdrawn below the upper surface of said bed; actuating means operable to elevate said support together with said movable blade through said gap for coaction with said fixed blade to sever a slide-fastener section overlying said gap from an adjoining section; and a spring-loaded shoe overhanging said gap above said support between said fixed blade and said needles, said shoe having a bottom surface normally disposed below the level of a cutting edge of said fixed blade but elevatable above said level upon entrainment by said support whereby said overlying section is clamped between said shoe and said support.
Claim 2
Dependent Claim
176 words
In a sewing machine for slide fasteners comprising a flat bed provided with a gap and a pair of parallel needles aligned with said gap for straddling two interlinked slide-fastener halves while stitching same onto a workpiece moving along said bed, the combination therewith of: a fixed cutter blade spacedly disposed above said gap downstream of said needles; a movable cutter blade confronting said fixed blade in operative alignment therewith; a support for said movable blade normally withdrawn below the upper surface of said bed; actuating means operable to elevate said support together with said movable blade through said gap for coaction with said fixed blade to sever a slide-fastener section overlying said gap from an adjoining section; and a spring-loaded shoe overhanging said gap above said support between said fixed blade and said needles, said shoe having a bottom surface normally disposed below the level of a cutting edge of said fixed blade but elevatable above said level upon entrainment by said support whereby said overlying section is clamped between said shoe and said support.
Claim 3
Dependent Claim
19 words
The combination defined in claim 1 wherein said support has an upper face with a recess accommodating said shoe.
Claim 4
Dependent Claim
57 words
The combination defined in claim 1, further comprising welding means fixedly disposed above said bed for contact with a slide-fastener section clamped between said support and said shoe upon elevation thereof to fuse part of the clamped section into an end stop, said welding means having a fastener-engaging point lying above the level of said cutting edge.
Claim 5
Dependent Claim
49 words
The combination defined in claim 1, further comprising a spring-loaded presser foot disposed upstream of said shoe in the vicinity of said needles, further comprising a holder for said shoe secured to said presser foot and guide means mounting said shoe on said holder wit limited relative vertical mobility.
Claim 6
Dependent Claim
22 words
The combination defined in claim 1 wherein said shoe has a cutout penetrated by said fastener-engaging point upon elevation of said shoe.
Claim 7
Dependent Claim
14 words
The combination defined in claim 3 wherein said welding means comprises a supersonic vibrator.
Claim 8
Dependent Claim
14 words
The combination defined in claim 1 wherein said actuating means comprises a fluid-operated piston.
Claim 9
Dependent Claim
24 words
The combination defined in claim 1 wherein said movable blade has a cutting edge normally lying substantially at the level of said upper surface.
Claim 10
Dependent Claim
25 words
The combination defined in claim 8 wherein said movable blade is chamfered with a land sloping downwardly from the cutting edge thereof toward said needles.
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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |