US3921552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Work feed mechanisms for sewing machines
Assignee: Singer Co
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Filing: 1975-03-20
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Granted: 1975-11-25
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Expires: 1995-03-20
Abstract
Abstract In a work feed mechanism for a sewing machine in which a feed dog is pivotally supported by a bidirectional joint on one end of a feed bar which is oscillated by feed and lift cams to determine work feed and return strokes of the feed dog, means for constraining the feed dog so that the work fabric is transported in a straight line transversely of the work supporting surface. This constraining means comprises a block secured to the machine frame which has a throat into which is received a guide pin secured to a feed dog carrier so that the guide pin is under the control of the constraining block to maintain the feed dog parallel to the work support surface and parallel to the direction of the work feed although swinging in an arcuate or elliptical path in response to movement of the feed bar.
Inventors
- 👤 Louis F Daman
- 👤 Stanley J Ketterer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:20
CPC Classifications
D; D05; D05B; D05B27/00; D05B27/02
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
250 words
A work feeding mechanism for a sewing machine having a work supporting surface on the bed of the machine for feeding said work fabric transversely across said work supporting surface, said work feeding mechanism comprising: an elongated feed bar arranged in said bed and extending substantially perpendicular to the work feed direction, a feed dog arranged to engage said work and transport the same on said work supporting surface, means beneath said work supporting surface pivotally securing said feed dog to one extremity of said feed bar, gimbal means mounted in said bed and engaging the opposite extremity of said feed bar, drive means operable in timed relation with said sewing machine for oscillating said feed bar about said gimbal means in mutually perpendicular directions, one direction being transversely of said work supporting surface to provide the work feed and return strokes of said feed dog and the other direction being toward and away from said work supporting surface to raise said feed dog to a position above said work supporting surface during the work feed stroke and to drop said feed dog below said work supporting surface during the return stroke, constraining means located below said means pivotally securing said feed dog to said feed bar and affixed to said machine bed for maintaining said feed dog substantially straight with respect to the work supporting surface so the said feed dog remains parallel to the work supporting surface and the work fabric is fed on a substantially straight line.
Claim 2
Dependent Claim
250 words
A work feeding mechanism for a sewing machine having a work supporting surface on the bed of the machine for feeding said work fabric transversely across said work supporting surface, said work feeding mechanism comprising: an elongated feed bar arranged in said bed and extending substantially perpendicular to the work feed direction, a feed dog arranged to engage said work and transport the same on said work supporting surface, means beneath said work supporting surface pivotally securing said feed dog to one extremity of said feed bar, gimbal means mounted in said bed and engaging the opposite extremity of said feed bar, drive means operable in timed relation with said sewing machine for oscillating said feed bar about said gimbal means in mutually perpendicular directions, one direction being transversely of said work supporting surface to provide the work feed and return strokes of said feed dog and the other direction being toward and away from said work supporting surface to raise said feed dog to a position above said work supporting surface during the work feed stroke and to drop said feed dog below said work supporting surface during the return stroke, constraining means located below said means pivotally securing said feed dog to said feed bar and affixed to said machine bed for maintaining said feed dog substantially straight with respect to the work supporting surface so the said feed dog remains parallel to the work supporting surface and the work fabric is fed on a substantially straight line.
Claim 3
Dependent Claim
31 words
The work feed mechanism as claimed in claim 1 further including a carrier supporting said feed dog and wherein said constraining means includes means connecting sAid constraining means to said carrier.
Claim 4
Dependent Claim
27 words
The work feed mechanism as claimed in claim 2 wherein said constraining means comprises a constraining block with a throat means opening upwardly toward said feed dog.
Claim 5
Dependent Claim
33 words
The work feed mechanism as claimed in claim 3 wherein said means connecting said constraining means to said carrier comprises a guide means received in said throat means and affixed to said carrier.
Claim 6
Dependent Claim
17 words
The work feed mechanism as claimed in claim 4 wherein said guide means comprises a guide pin.
Claim 7
Dependent Claim
38 words
The work feeding mechanism as claimed in claim 5 wherein said constraining block further includes a liner forming part of said throat means and providing a means for adjusting said throat means with respect to said guide pin.
References Cited (Backward Citations)
US2906220A
Cited
US3527183A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |