Patent US4392494A successfully refreshed from Google Patents.
US4392494A
Expired / Lapsed
US
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Ligature tying instrument
Assignee: Individual
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Filing: 1981-04-02
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Granted: 1983-07-12
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Expires: 2001-04-02
Abstract
Abstract This patent describes a new orthodontic instrument to be used for tying or twisting the ligature wires used to hold the arch wire to the bracket. It also explains the method of use which consists of: twisting the wires, after the ligature wire has been placed on the bracket; tucking the twisted end out of the way; and then breaking the end at the tip of the instrument. The instrument replaces three instruments normally used, by improvements in jaw design to facilitate grasping and centering the wires for spinning, balancing the instrument by general symmetry, and the addition of an extension handle to allow rapid spinning, and tucking of the wire ends as they are broken in a controlled manner, and at a specific place. The instrument thus simplifies, speeds and further improves the application of ligature wires.
Inventors
- 👤 Richard L. Ashby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:01
CPC Classifications
A; A61; A61B; A61B17/00; A61B17/12; A61B17/12009; A61C; A61C7/00; A61C7/02; A61C7/026; A61C7/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
134 words
An improvement in ligature tying instrument comprising a hemostat-like plier in which grasping jaw members are flexibly pivoted together intermediate their ends; means for releasably securing said jaws in grasping position on a ligature wire; wherein the improvement comprises a balanced and substantially symmetrical instrument having one handle member extended as a polygonal rod rigidly fixed in the long axis of the instrument for purposes of spinning the instrument about a longitudinal centerline, when said instrument is locked in the grasping position; wherein the grasping face of the jaw members is concave except right at the tip, such that closure of the jaws tends to force the grasped wires toward the long axis of the instrument for purposes of centering the wires and maintaining their central position during the twisting, tucking and breaking process.
Claim 2
Dependent Claim
134 words
An improvement in ligature tying instrument comprising a hemostat-like plier in which grasping jaw members are flexibly pivoted together intermediate their ends; means for releasably securing said jaws in grasping position on a ligature wire; wherein the improvement comprises a balanced and substantially symmetrical instrument having one handle member extended as a polygonal rod rigidly fixed in the long axis of the instrument for purposes of spinning the instrument about a longitudinal centerline, when said instrument is locked in the grasping position; wherein the grasping face of the jaw members is concave except right at the tip, such that closure of the jaws tends to force the grasped wires toward the long axis of the instrument for purposes of centering the wires and maintaining their central position during the twisting, tucking and breaking process.
Claim 3
Dependent Claim
30 words
An instrument as in claim 1; wherein, the grasping faces of the jaw members are serrated such that the peaks of the individual serrations would lie in a concave surface.
Claim 4
Dependent Claim
27 words
An instrument as in claim 1; wherein, the face of the grasping portion of the jaw member has serrations which are serrated, forming a compounding of serrations.
Claim 5
Dependent Claim
54 words
An instrument as in claim 1; wherein, the general contour of the face of the grasping portion of the jaw member is cylindrical in part and conical in part, whereby increased pressure is applied at the tip of the jaw member allowing twisted wires to be broken at the tip in a controlled manner.
Claim 6
Dependent Claim
54 words
An instrument as in claim 1; wherein, the general contour of the face of the grasping portion of the jaw member is cylindrical in part and spherical in part, whereby increased pressure is applied at the tip of the jaw member allowing twisted wires to be broken at the tip in a controlled manner.
References Cited (Backward Citations)
GB479719A
Cited
US2393910A
Cited
US3420280A
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US3393680A
Cited
US3577991A
Cited
US3621890A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-11 | 1987-01-10 | 1987-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-11 | 1991-01-10 | 1991-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-11 | 1995-01-10 | 1995-07-12 | $7700.00 | Window Closed / Lapsed |