US3865293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Subsurface cracks
Assignee: PPG Industries Inc
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Filing: 1972-04-10
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Granted: 1975-02-11
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Expires: 1992-04-10
Abstract
Abstract Pieces of flat glass are cut to desired size without the necessity of grinding to size and polishing. Edges of the piece are cut in accordance with a procedure involving the use of a large-diameter scoring wheel at a greater-than-usual applied pressure, to produce a subsurface crack that is substantially free of serrations, followed by the application of a bending moment about the crack to propagate a fracture in the piece of glass. Light seaming of the top and bottom portions of the edges completes the preparation of these edges.
Inventors
- 👤 Fred M Ernsberger
- 👤 Charles M Hollabaugh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:26
CPC Classifications
C; C03; C03B; C03B33/00; C03B33/10; C03B33/105; C03B33/107; C03B33/02; C03B33/023; C03B33/033; C03B33/09; C03B33/091; Y; Y02; Y02P; Y02P40/00; Y02P40/50; Y02P40/57; Y10; Y10T; Y10T225/00; Y10T225/10; Y10T225/12; Y10T428/00; Y10T428/15
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
80 words
A method of producing a cut edge on a piece of glass comprising the steps of: applying a force to produce an indentation in a major surface of the glass and, concurrently, a subsurface discontinuity therebelow along an intended path of cut, at least a substantial portion of said discontinuity, along its length, being spaced from said major surface by a zone of glass, and projecting said discontinuity deeper into the thickness of said glass after said discontinuity is produced.
Claim 2
Independent Claim
80 words
A method of producing a cut edge on a piece of glass comprising the steps of: applying a force to produce an indentation in a major surface of the glass and, concurrently, a subsurface discontinuity therebelow along an intended path of cut, at least a substantial portion of said discontinuity, along its length, being spaced from said major surface by a zone of glass, and projecting said discontinuity deeper into the thickness of said glass after said discontinuity is produced.
Claim 3
Dependent Claim
26 words
A method of producing a cut edge as defined in claim 1, wherein all of said discontinuity is spaced from the major surfaces of the glass.
Claim 4
Dependent Claim
25 words
A method of producing a cut edge as defined in claim 1, wherein said discontinuity is projected by applying a bending moment about said discontinuity.
Claim 5
Dependent Claim
26 words
A method of producing a cut edge as defined in claim 1, further including the step of: grinding upper and lower portions of said cut edge.
Claim 6
Dependent Claim
26 words
A method of producing a cut edge as defined in claim 1, further including the step of: seaming upper and lower portions of said cut edge.
Claim 7
Dependent Claim
26 words
A method of producing a cut edge as defined in claim 3, further including the step of: grinding upper and lower portions of said cut edge.
Claim 8
Dependent Claim
26 words
A method oF producing a cut edge as defined in claim 3, further including the step of: seaming upper and lower portions of said cut edge.
Claim 9
Dependent Claim
29 words
A method of producing a cut edge as defined in claim 1, wherein said discontinuity is produced by a wheel having a diameter of at least approximately 12 millimeters.
Claim 10
Dependent Claim
39 words
A method of producing a cut edge as defined in claim 8, further including the step of: placing a surface defect in the glass along the intended path of cut before the discontinuity is produced to initiate the discontinuity.
Claim 11
Dependent Claim
22 words
A method of producing a cut edge as defined in claim 9, wherein said wheel has a cutting angle of approximately 165*.
Claim 12
Dependent Claim
24 words
A method of producing a cut edge as defined in claim 9, wherein said wheel has a cutting angle of from 155* to 170*.
Claim 13
Dependent Claim
38 words
A method of producing a cut edge as defined in claim 11, wherein said wheel has an integral shaft at the center thereof, said shaft being mounted in bearings to reduce friction between said wheel and a holder.
Claim 14
Dependent Claim
27 words
A method of producing a cut edge as defined in claim 12, wherein said wheel produces said discontinuity at a force of at least about 80 kilograms.
Claim 15
Dependent Claim
32 words
A method of producing a cut edge as defined in claim 13, wherein said wheel travels along the intended path of cut at a speed up to approximately 2 meters per second.
Claim 16
Dependent Claim
25 words
A method of producing a cut edge as defined in claim 13, wherein said discontinuity is projected by applying a bending moment about said crack.
Claim 17
Dependent Claim
32 words
A method of producing a cut edge as defined in claim 15, wherein said wheel travels along the intended path of cut at a speed up to approximately 2 meters per second.
Claim 18
Dependent Claim
72 words
A glass article having a top surface, a bottom surface and a cut edge extending therebetween in a direction substantially perpendicular to said top surface and said bottom surface, said cut edge having a smooth, strong fracture area, a seamed indentation and subsurface discontinuity area adjacent to one of said top surface and said bottom surface, and a seamed area adjacent to the other of said top surface and said bottom surface.
Claim 19
Dependent Claim
72 words
A glass article having a top surface, a bottom surface and a cut edge extending therebetween in a direction substantially perpendicular to said top surface and said bottom surface, said cut edge having a smooth, strong fracture area, a seamed indentation and subsurface discontinuity area adjacent to one of said top surface and said bottom surface, and a seamed area adjacent to the other of said top surface and said bottom surface.
Claim 20
Dependent Claim
46 words
A glass article having a top surface, a bottom surface and an indentation and a subsurface discontinuity extending along said article along an intended path of cut, a substantial portion of said discontinuity, along its length, being spaced from the top surface and the bottom surface.
Claim 21
Dependent Claim
46 words
A glass article having a top surface, a bottom surface and an indentation and a subsurface discontinuity extending along said article along an intended path of cut, a substantial portion of said discontinuity, along its length, being spaced from the top surface and the bottom surface.
Claim 22
Dependent Claim
77 words
A glass article having a top surface, a bottom surface and a cut edge extending therebetween in a direction substantially perpendicular to said top surface and said bottom surface, said cut edge containing an indentation area and spaced therebelow two markings with an area therebetween that is substantially free of serrations, each of said markings being substantially parallel to said top surface and said bottom surface, said markings being indicative of the extent of a subsurface discontinuity.
Claim 23
Dependent Claim
77 words
A glass article having a top surface, a bottom surface and a cut edge extending therebetween in a direction substantially perpendicular to said top surface and said bottom surface, said cut edge containing an indentation area and spaced therebelow two markings with an area therebetween that is substantially free of serrations, each of said markings being substantially parallel to said top surface and said bottom surface, said markings being indicative of the extent of a subsurface discontinuity.
Claim 24
Dependent Claim
42 words
A glass article as defined in claim 19, wherein one of said markings is at least approximately 0.01 millimeter from one of said surfaces and the other of said markings is up to approximately 4 millimeters from said one of said surfaces.
Claim 25
Dependent Claim
26 words
A method of producing a cut edge as defined in claim 8, wherein said wheel has a cutting angle of from about 163* to approximately 170*.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-10 | 1978-08-12 | 1979-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-10 | 1982-08-12 | 1983-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-10 | 1986-08-12 | 1987-02-11 | $7700.00 | Window Closed / Lapsed |