Patent US1298590A successfully refreshed from Google Patents.
US4177524A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Medical securement element with abrasive grains on thread surface
Assignee: Pfaudler Inc
•
Filing: 1977-05-10
•
Granted: 1979-12-11
•
Expires: 1997-05-10
Abstract
Abstract A medical securement element with a self-tapping screw thread is provided with biocompatible abrasive grains at the surface of the thread. The grains are preferably embedded in a layer of porcelain enamel on a metal substrate.
Inventors
- 👤 Helmut Grell
- 👤 Heinz Scharbach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:18
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/28; A61L27/30; A61L27/32; A61B; A61B17/00; A61B17/56; A61B17/58; A61B17/68; A61B17/84; A61B17/86; A61B17/8625; A61C; A61C8/00; A61C8/0012; A61C8/0013; A61C8/0018; A61C8/0022; A61F; A61F2/00; A61F2/02; A61F2/30; A61F2/30767; A61F2/30771; A61F2/32; A61F2/36; A61F2/3662; A61B17/16; A61B17/1655; A61F2002/30001; A61F2002/30316; A61F2002/30329; A61F2002/30331; A61F2002/30332; A61F2002/3085; A61F2002/30858; A61F2220/00; A61F2220/0025; A61F2220/0033; A61F2310/00; A61F2310/00389; A61F2310/00592; A61F2310/00598; A61F2310/0061; A61F2310/00796; A61F2310/00928; A61F2310/00934
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
27 words
A medical securement element for engagement with a counterthread in a bone, comprising a self-tapping screw thread with biocompatible abrasive grains at the surface of the thread.
Claim 2
Dependent Claim
27 words
A medical securement element for engagement with a counterthread in a bone, comprising a self-tapping screw thread with biocompatible abrasive grains at the surface of the thread.
Claim 3
Dependent Claim
15 words
A securement element according to claim 1 wherein the abrasive grains comprise calcium hydroxyl apatite.
Claim 4
Dependent Claim
14 words
A securement element according to claim 1 wherein the abrasive grains comprise quartz sand.
Claim 5
Dependent Claim
19 words
A securement element according to claim 1 wherein the abrasive grains have a maximum grain size of 0.7 mm.
Claim 6
Dependent Claim
21 words
A securement element according to claim 4 wherein the abrasive grains have a grain size ranging from 0.2 to 0.4 mm.
Claim 7
Dependent Claim
17 words
A securement element according to claim 1 wherein the abrasive grains are embedded in an enamel layer.
Claim 8
Dependent Claim
33 words
A securement element according to claim 6 wherein the thread is covered with a layer comprising 20% to 60% by weight of said abrasive grains, the balance of said layer being enamel matrix.
Claim 9
Dependent Claim
40 words
A securement element according to claim 1 wherein the thread is subdivided by cut-out notches into thread segments and the thread segments in each row of segments are displaced circumferentially in relation to the thread segments of each adjacent row.
Claim 10
Dependent Claim
44 words
A securement element according to claim 8 wherein each thread segment is displaced circumferentially from thread segments in adjacent rows by one-half the distance between the midpoints of adjacent thread segments, whereby each thread segment is aligned with the cut-out notches in adjacent rows.
Claim 11
Dependent Claim
36 words
A securement element according to claim 8, having a conical thread, wherein the distance between the midpoints of adjacent thread segments increases from one thread segment to the next in the direction of increasing thread diameter.
Claim 12
Dependent Claim
104 words
A securement element according to claim 1 wherein the thread is subdivided by cut-out notches into thread segments and the ratio of the maximally stressed cross-sectional surface of each thread segment to the area enclosed by a first line along the apex of said thread segment, a second line along the apex of an axially adjacent thread segment, a third line extending through one end of said thread segment at right angles to said first line, and a fourth line extending through the other end of said thread segment at right angles to said first line is in the range from 1:1 to 0.1:1.
References Cited (Backward Citations)
US3435526A
Cited
US3787900A
Cited
US3924275A
Cited
US3905047A
Cited
US3987499A
Cited
US3971073A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-10 | 1983-06-11 | 1983-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-10 | 1987-06-11 | 1987-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-10 | 1991-06-11 | 1991-12-11 | $7700.00 | Window Closed / Lapsed |