US3986227A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Printing system having a hot roll fuser with a scraping blade cleaner
Assignee: International Business Machines Corp
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Filing: 1975-05-19
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Granted: 1976-10-19
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Expires: 1995-05-19
Abstract
Abstract In a xerographic printing system the toned copy paper is fused by the pressure nip formed by a hot roll and a backup roll. A scraping blade engages the destructible surface of the backup roll at a critical angle which is selected as a function of the coefficients of friction of the backup roll's surface and the toner/debris contamination that may be collected on the backup roll's surface. As a result, the blade slides freely on the roll's surface, but does not slide on the surface of the toner/debris contamination film. This film forms a locking angle with the blade, placing the blade in stress, and developing a film removing chisel-like action therewith.
Inventors
- 👤 Rex D. Fathergill
- 👤 Arthur M. Howarth
- 👤 Edward L. Soard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:07
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2003; G03G15/2014; G03G15/2017; G03G15/2025
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
129 words
A scraping cleaning apparatus for cleaning contaminating material from the surface of a roll, wherein the coefficient of friction of the roll's surface is less than the coefficient of friction of the contaminating material, the apparatus comprising: a scraping blade having a sharp leading edge positioned to engage the advancing surface of said roll with a given force and at a critical acute angle from the tangent to the roll at the point of engagement, said critical angle being such that the friction-derived force vector lies at a greater angle than said critical angle when said leading edge engages a clean roll surface, and such that the higher friction-derived force vector lies at a lesser angle than said critical angle when said leading edge engages a contaminated roll surface.
Claim 2
Dependent Claim
129 words
A scraping cleaning apparatus for cleaning contaminating material from the surface of a roll, wherein the coefficient of friction of the roll's surface is less than the coefficient of friction of the contaminating material, the apparatus comprising: a scraping blade having a sharp leading edge positioned to engage the advancing surface of said roll with a given force and at a critical acute angle from the tangent to the roll at the point of engagement, said critical angle being such that the friction-derived force vector lies at a greater angle than said critical angle when said leading edge engages a clean roll surface, and such that the higher friction-derived force vector lies at a lesser angle than said critical angle when said leading edge engages a contaminated roll surface.
Claim 3
Dependent Claim
59 words
The cleaning apparatus defined in claim 1 wherein said roll is of a finite axial length and rotates in a direction to advance against the leading edge of said blade, wherein said scraping blade is narrow as compared to the length of said roll, and including drive means to oscillate said blade axially back and forth across said roll.
Claim 4
Dependent Claim
156 words
In an electrophotographic copying apparatus having a hot roll fuser, a scraping blade cleaning apparatus for cleaning the fuser's backup roll, comprising: a fuser backup roll having an outer surface whose coefficient of friction is of a lower value than the coefficient of friction of the same surface when coated with a contaminant; and a scraping blade having a sharp leading edge positioned to engage the advancing surface of said roll with a given force bias and at a critical acute angle which is measured from the tangent to the roll at the point of engagement, said critical angle being a function of the two stated coefficients of friction and being such that the friction-derived force vector for a clean roll lies at a greater angle to said tangent than said critical angle, and the larger magnitude friction-derived force vector for a contaminated roll lies at a lesser angle to said tangent than said critical angle.
Claim 5
Dependent Claim
156 words
In an electrophotographic copying apparatus having a hot roll fuser, a scraping blade cleaning apparatus for cleaning the fuser's backup roll, comprising: a fuser backup roll having an outer surface whose coefficient of friction is of a lower value than the coefficient of friction of the same surface when coated with a contaminant; and a scraping blade having a sharp leading edge positioned to engage the advancing surface of said roll with a given force bias and at a critical acute angle which is measured from the tangent to the roll at the point of engagement, said critical angle being a function of the two stated coefficients of friction and being such that the friction-derived force vector for a clean roll lies at a greater angle to said tangent than said critical angle, and the larger magnitude friction-derived force vector for a contaminated roll lies at a lesser angle to said tangent than said critical angle.
Claim 6
Dependent Claim
30 words
In an electrophotographic copying apparatus as defined in claim 3, including a low surface energy material covering said backup roll and portions of said scraping blade excluding said leading edge.
Claim 7
Dependent Claim
27 words
The electrophotographic copying apparatus defined in claim 4 wherein said roll and said scraping blade are metallic, and said material having a low surface energy is polytetrafluoroethelene.
Claim 8
Dependent Claim
66 words
In an electrophotographic copying apparatus as defined in claim 3, wherein said backup roll is of a finite axial length and rotates in a direction to advance its outer surface into the leading edge of said blade, wherein said blade is narrow as compared to the axial length of said roll, and including drive means to oscillate said blade axially back and forth across said roll.
Claim 9
Dependent Claim
32 words
In an electrophotographic copying apparatus as defined in claim 6 wherein said contaminant includes toner, wherein said roll is metallic, and including a low surface energy material coating on said backup roll.
Claim 10
Dependent Claim
31 words
In an electrophotographic copying apparatus as defined in claim 7 wherein said blade is metallic, and including a low surface energy material coating surfaces of said blade excluding said leading edge.
Claim 11
Dependent Claim
16 words
The electrophotographic copying apparatus defined in claim 8 wherein said low surface energy material is polytetrafluoroethelene.
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) | 1979-10-19 | 1980-04-19 | 1980-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-19 | 1984-04-19 | 1984-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-19 | 1988-04-19 | 1988-10-19 | $7700.00 | Window Closed / Lapsed |