Patent US3887406A successfully refreshed from Google Patents.
US3887406A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of building board
Assignee: BPB Ltd
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Filing: 1972-10-24
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Granted: 1975-06-03
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Expires: 1992-10-24
Abstract
Abstract The invention relates to the reinforcement of the edges of cementitious board and especially plasterboard. Reinforcing strips are secured to at least one edge of the lower sheet employed in the manufacture of plasterboard and is incorporated with the sheet in the formed board as an edge reinforcement. The reinforcing strip may have any desired cross-section or profile but preferably has a channel section whereby the corners of the board are protected. It may also be grooved longitudinally to provide a kerfed edge to the board which is useful when securing the boards by means of concealed supports.
Inventors
- 👤 Thomas Gwynne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:23
CPC Classifications
B; B28; B28B; B28B19/00; B28B19/0092; E; E04; E04C; E04C2/00; E04C2/02; E04C2/04; E04C2/043; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/2419; Y10T428/24198; Y10T428/24777
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
175 words
A method for the production of lined cementitious board comprising the steps of: continuously advancing a first sheet in a generally horizontal plane; providing a reinforcing strip of rigid material formed with a section of desired non-planar profile; supplying such reinforcing strip to the upper surface of at least one lateral edge of said first sheet and securing said strip to said edge with such profile in a first orientation relative to said plane; depositing an aqueous slurry of cementitious material on the upper surface of said first sheet; folding the lateral edges of said first sheet upwards as the sheet advances and rotating said strip therewith from said first orientation into the orientation and disposition said strip will have in the finished board, without alteration of the profile of said strip; laying a second sheet over said slurry and the upwardly folded lateral edges of said first sheet; forming said slurry to the desired thickness; and securing said two sheets together at their lateral edges whereby said strip is incorporated in the formed board.
Claim 2
Independent Claim
175 words
A method for the production of lined cementitious board comprising the steps of: continuously advancing a first sheet in a generally horizontal plane; providing a reinforcing strip of rigid material formed with a section of desired non-planar profile; supplying such reinforcing strip to the upper surface of at least one lateral edge of said first sheet and securing said strip to said edge with such profile in a first orientation relative to said plane; depositing an aqueous slurry of cementitious material on the upper surface of said first sheet; folding the lateral edges of said first sheet upwards as the sheet advances and rotating said strip therewith from said first orientation into the orientation and disposition said strip will have in the finished board, without alteration of the profile of said strip; laying a second sheet over said slurry and the upwardly folded lateral edges of said first sheet; forming said slurry to the desired thickness; and securing said two sheets together at their lateral edges whereby said strip is incorporated in the formed board.
Claim 3
Independent Claim
89 words
A METHOD FOR THE PRODUCTION OF LINED CEMENTITIOUS BOARD COMPRISING THE STEPS OF: CONTINUOUSLY ADVANCING A FIRST SHEET IN A GENERALLY HORIZONTAL PLANE; PROVIDING A REINFORCING STRIP OF RIGID MATERIAL FORMED WITH A SECTION OF DESIRED NON-PLANAR PROFILE; SUPPLYING SUCH REINFORCING STRIP TO THE UPPER SURFACE OF AT LEAST ONE LATERAL EDGE OF SAID FIRST SHEET AND SECURING SAID STRIP TO SAID EDGE WITH SUCH PROFILE IN A FIRST ORIENTATION RELATIVE TO SAID PLANE; DEPOSITING AN AQUEOUS SLURRY OF CEMENTITIOUS MATEIRAL ON THE UPPER SURFACE OF SAID FIRST SHEET;
Claim 4
Independent Claim
89 words
A METHOD FOR THE PRODUCTION OF LINED CEMENTITIOUS BOARD COMPRISING THE STEPS OF: CONTINUOUSLY ADVANCING A FIRST SHEET IN A GENERALLY HORIZONTAL PLANE; PROVIDING A REINFORCING STRIP OF RIGID MATERIAL FORMED WITH A SECTION OF DESIRED NON-PLANAR PROFILE; SUPPLYING SUCH REINFORCING STRIP TO THE UPPER SURFACE OF AT LEAST ONE LATERAL EDGE OF SAID FIRST SHEET AND SECURING SAID STRIP TO SAID EDGE WITH SUCH PROFILE IN A FIRST ORIENTATION RELATIVE TO SAID PLANE; DEPOSITING AN AQUEOUS SLURRY OF CEMENTITIOUS MATEIRAL ON THE UPPER SURFACE OF SAID FIRST SHEET;
Claim 5
Dependent Claim
19 words
A method according to claim 1 wherein the strip is secured to the sheet by a hot melt adhesive.
Claim 6
Dependent Claim
24 words
A method according to claim 1 wherein the strip is pressed into contact with the first facing sheet by a pair of cooperating rollers.
Claim 7
Dependent Claim
25 words
A method according to claim 1 wherein the width of the reinforcing strip is substantially equal to the thickness of the core of the board.
Claim 8
Dependent Claim
35 words
A method according to claim 1 wherein the reinforcing strip has a flanged channel section and is secured with the channel opening downwards on the upper surface of the first sheet in said first orientation.
Claim 9
Dependent Claim
12 words
A method according to claim 1 wherein the reinforcing strip is perforated.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |