Patent US4566778A successfully refreshed from Google Patents.
US4566778A
Expired / Lapsed
US
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Pressure fixing device
Assignee: Proterial Ltd
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Filing: 1983-04-15
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Granted: 1986-01-28
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Expires: 2003-04-15
Abstract
Abstract A pressure fixing device including at least a pair of fixing rolls maintained in pressing engagement with each other such that their axes cross each other at a small angle θ 1 to allow a supporter supporting a toner image thereon to pass therebetween at a velocity V 2 higher than the peripheral velocity V 1 of the fixing rolls, and a guide member located anterior to the fixing rolls with respect to the direction of movement of the supporter and having a forward end located in spaced juxtaposed relation to peripheral surfaces of the fixing rolls. The peripheral velocity V 1 of the fixing rolls is set such that the ratio V 1 /V 2 is above 0.95, and the guide member is arranged such that a gap between the forward end of the guide member and the fixing rolls is about 5-20 times greater than the thickness of the supporter before fixing of the toner image is effected at least in a central portion of the length of the fixing rolls. A line of contact between the fixing rolls is inclined at a small angle θ' with respect to a straight line perpendicular to the direction of movement of the supporter.
Inventors
- 👤 Yoshitaka Sasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:21
CPC Classifications
B; B41; B41F; B41F23/00; B41F23/08; G; G03; G03G; G03G15/00; G03G15/20; G03G15/2092
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
257 words
In a pressure fixing device having at least a pair of fixing rolls each having peripheral velocity V 1 and maintained in a pressing engagement with each other such that their axes cross each other at a small angle θ 1 to allow a supporter supporting a toner image thereon to move in a direction therebetween at a velocity V 2 , one of the fixing rolls contacting and fixing the toner image on the supporter during movement of the supporter between the rolls; and a guide member located anterior to the fixing rolls with respect to the direction of movement of the supporter and having a forward end located in spaced juxtaposed relation to peripheral surfaces of the fixing rolls; wherein the improvement comprises that: the peripheral velocity V 1 of the fixing rolls is set such that V 2 ≧V 1 and the ratio V 1 /V 2 is above about 0.95; A guide member is arranged such that a gap between the forward end of the guide member and the surface of that one of the fixing rolls disposed to contact the toner image is of a dimension about 5-20 times greater than the thickness of the supporter before fixing of the toner image is effected, said gap dimension occurring at least at a central portion of the length of the fixing rolls; and a line of contact between the fixing rolls is inclined at a small angle θ' with respect to a straight line perpendicular to the direction of movement of the supporter.
Claim 2
Dependent Claim
257 words
In a pressure fixing device having at least a pair of fixing rolls each having peripheral velocity V 1 and maintained in a pressing engagement with each other such that their axes cross each other at a small angle θ 1 to allow a supporter supporting a toner image thereon to move in a direction therebetween at a velocity V 2 , one of the fixing rolls contacting and fixing the toner image on the supporter during movement of the supporter between the rolls; and a guide member located anterior to the fixing rolls with respect to the direction of movement of the supporter and having a forward end located in spaced juxtaposed relation to peripheral surfaces of the fixing rolls; wherein the improvement comprises that: the peripheral velocity V 1 of the fixing rolls is set such that V 2 ≧V 1 and the ratio V 1 /V 2 is above about 0.95; A guide member is arranged such that a gap between the forward end of the guide member and the surface of that one of the fixing rolls disposed to contact the toner image is of a dimension about 5-20 times greater than the thickness of the supporter before fixing of the toner image is effected, said gap dimension occurring at least at a central portion of the length of the fixing rolls; and a line of contact between the fixing rolls is inclined at a small angle θ' with respect to a straight line perpendicular to the direction of movement of the supporter.
Claim 3
Dependent Claim
33 words
The pressure fixing device as claimed in claim 1, wherein the peripheral velocity V 1 of the fixing rolls is set such that the ratio V 1 /V 2 is above about 0.98.
Claim 4
Dependent Claim
26 words
The pressure fixing device as claimed in claim 2, wherein the value of θ' is above about 1/10 θ 1 and substantially below θ 1 .
Claim 5
Dependent Claim
42 words
The pressure fixing device as claimed in claim 1, further including said guide means having a supporter-contacting surface curved in a direction transverse to the direction of movement of the supporter, said curvature being convex as viewed from said one fixing roll.
Claim 6
Dependent Claim
36 words
The pressure fixing device as claimed in claim 4 wherein the curvature of said guide member surface results in a central surface portion displacement of less than about 1 mm relative to the outer surface portions.
Claim 7
Dependent Claim
76 words
The pressure fixing device as claimed in claim 1, further including said guide means having a supporter-contacting surface curved in a direction transverse to the direction of movement of the supporter, said curvature being convex with respect to said one fixing roll, and wherein at least the portions of said guide member surface transversely distant the central fixing roll portion are located in positions below the position of the line of contact between the fixing rolls.
Claim 8
Dependent Claim
23 words
The pressure fixing device as claimed in claim 6 wherein all portions of said guide member surface are below the contact line position.
Claim 9
Dependent Claim
36 words
The pressure fixing device as claimed in claim 1, wherein the forward end of said guide member is located in a position at or below the position of the line of contact between the fixing rolls.
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) | 1989-01-27 | 1989-07-29 | 1990-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-01-27 | 1993-07-29 | 1994-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-01-27 | 1997-07-29 | 1998-01-28 | $7700.00 | Window Closed / Lapsed |