US4214540A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Variable presser bar pressure control arrangement
Assignee: Retail Holding NV
•
Filing: 1979-05-30
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Granted: 1980-07-29
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Expires: 1999-05-30
Abstract
Abstract A sewing machine having a presser bar operated by a lever having a movable fulcrum to vary the mechanical advantage of the lever and thereby vary the effective pressure on the presser bar.
Inventors
- 👤 Albert N. Cook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:53
CPC Classifications
D; D05; D05B; D05B29/00; D05B29/02
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
117 words
In a sewing machine comprising a body, a feed mechanism for incrementally advancing a work piece to produce a series of stitches, and a presser bar with a presser foot attached thereto for urging said work piece into engagement with said feed mechanism, variable presser bar pressure control means comprising: a rigid lever, said presser bar operatively engaging said lever at a first point on said lever; means for applying a predetermined force to a second point on said lever spaced from said first point; a shiftable fulcrum for said lever; and means for shifting said fulcrum along said lever to vary the mechanical advantage of said lever to control the pressure applied to said presser bar.
Claim 2
Dependent Claim
117 words
In a sewing machine comprising a body, a feed mechanism for incrementally advancing a work piece to produce a series of stitches, and a presser bar with a presser foot attached thereto for urging said work piece into engagement with said feed mechanism, variable presser bar pressure control means comprising: a rigid lever, said presser bar operatively engaging said lever at a first point on said lever; means for applying a predetermined force to a second point on said lever spaced from said first point; a shiftable fulcrum for said lever; and means for shifting said fulcrum along said lever to vary the mechanical advantage of said lever to control the pressure applied to said presser bar.
Claim 3
Dependent Claim
44 words
The variable presser bar pressure control arrangement as set forth in claim 1 in which said means for applying a predetermined force to a second point on said lever comprises resilient means between said lever and a fixed location with respect to said body.
Claim 4
Dependent Claim
47 words
The variable presser bar pressure control arrangement as set forth in claim 1 which further comprises means for varying said predetermined amount of said predetermined force applied to said lever to vary the range of pressure over which said variable presser bar pressure control arrangement may operate.
Claim 5
Dependent Claim
41 words
The variable presser bar pressure control arrangement as set forth in claim 1 in which said fulcrum engages said lever over a range of points between said first and second points under the control of said means for shifting said fulcrum.
Claim 6
Dependent Claim
77 words
The variable presser bar pressure control arrangement as set forth in claim 4 in which said means for applying a predetermined force to a second point on said lever comprises a spring connected to said body and exerting said predetermined force at said second point on said lever near one end of said lever, said arrangement further comprising a second spring connected between said body and a third point on said lever near the other end thereof.
Claim 7
Dependent Claim
46 words
The variable presser bar pressure control arrangement as set forth in claim 5 in which said first point on said lever at which said rigid lever is operatively connected to said presser bar is between said third point and any point in said range of points.
Claim 8
Dependent Claim
38 words
The variable presser bar pressure control arrangement as set forth in claim 1 in which said means for applying said predetermined force comprises: spring biasing means; and means for constraining said spring biasing means relative to said lever.
Claim 9
Dependent Claim
72 words
The variable presser bar pressure control arrangement as set forth in claim 7 in which said means for constraining said spring biasing means comprises: a first threaded member connected to said body; and a second threaded member threadedly engaging said first threaded member and connected to said spring to control the force exerted by said spring on said lever by rotation of one of said threaded bodies with respect to the other.
Claim 10
Dependent Claim
60 words
The variable presser bar pressure control arrangement as set forth in claim 1 which further comprises: a first fulcrum-engaging surface on said lever substantially coincident with the path of shifting movement of said fulcrum; and a second fulcrum-engaging surface attached to said body, said fulcrum bearing against said second fulcrum-engaging surface, and said first fulcrum-engaging surface bearing against said fulcrum.
Claim 11
Dependent Claim
30 words
The variable presser bar pressure control arrangement as set forth in claim 9 in which said second fulcrum-engaging surface is substantially parallel to the direction of movement of said fulcrum.
Claim 12
Dependent Claim
31 words
The variable presser bar pressure control arrangement as set forth in claim 1 or 10 wherein said means for shifting the location of engagement of said fulcrum comprises a linear motor.
Claim 13
Dependent Claim
53 words
The variable presser bar pressure control arrangement as set forth in claim 9 in which said first and second fulcrum-engaging surfaces remain substantially fixed with respect to each other with respect to their mutual longitudinal directions, whereas said shiftable fulcrum is movable longitudinally with respect to said lever and said second fulcrum-engaging surface.
Claim 14
Dependent Claim
35 words
The variable presser bar pressure control arrangement as set forth in claim 9 wherein said fulcrum comprises roller means for engaging said first and second fulcrum engaging surfaces to facilitate the shifting of said fulcrum.
References Cited (Backward Citations)
US1202224A
Cited
US2280193A
Cited
US2827006A
Cited
US3366083A
Cited
US3815529A
Cited
US3984745A
Cited
US4067275A
Cited
US4016441A
Cited
US4056071A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-07-29 | 1984-01-28 | 1984-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-29 | 1988-01-28 | 1988-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-29 | 1992-01-28 | 1992-07-29 | $7700.00 | Window Closed / Lapsed |