← Back to Patent Explorer
US4440486A Expired / Lapsed US ⏱️ 0.0 years remaining

Fixing apparatus

Assignee: Canon Inc
•
Filing: 1982-04-16
•
Granted: 1984-04-03
•
Expires: 2002-04-16
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract The present invention relates to a fixing apparatus for use in electrophotographic copying machine or other image forming apparatus such as data recorder. More particularly, the present invention relates to a fixing apparatus of the type in which a toner image bearing member is pressed by a nip pressure between a pair of rotary members so as to fix the toner image onto the bearing member. The fixing apparatus of the present invention is characterized by the provision of limiting device for restraining the inter-axis distance between the two rotary members from increasing more than a predetermined value.

Inventors

  • 👤 Kazuo Isaka
  • 👤 Fumitaka Kan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 17:22
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/20; G03G15/2092

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 131 words
A fixing apparatus of the type in which a nip pressure is applied to a toner image bearing member between a pair of rotary members to fix the toner image onto the bearing member, said fixing apparatus comprising: a first rotary member; a second rotary member disposed to nip a toner image bearing member between said first and second rotary members; support means for rotatably supporting said rotary members; a pressing means for applying a pressing force between said first and second rotary members; and limiting means, which, at least when said toner image bearing member enters between said first and second rotary members, act on said support means independently from said pressing means for restraining the inter-axis distance between said two rotary members from increasing more than a predetermined value.
Claim 2
Dependent Claim 131 words
A fixing apparatus of the type in which a nip pressure is applied to a toner image bearing member between a pair of rotary members to fix the toner image onto the bearing member, said fixing apparatus comprising: a first rotary member; a second rotary member disposed to nip a toner image bearing member between said first and second rotary members; support means for rotatably supporting said rotary members; a pressing means for applying a pressing force between said first and second rotary members; and limiting means, which, at least when said toner image bearing member enters between said first and second rotary members, act on said support means independently from said pressing means for restraining the inter-axis distance between said two rotary members from increasing more than a predetermined value.
Claim 3
Dependent Claim 26 words
A fixing apparatus according to claim 1, wherein said limiting means acts on the side of toner image bearing member transporting reference of the supporting means.
Claim 4
Dependent Claim 20 words
A fixing apparatus according to claim 1 or 2, wherein said limiting member is formed of a rigid member. means
Claim 5
Dependent Claim 18 words
A fixing apparatus according to claim 3, wherein said limiting means is in the form of U character.
Claim 6
Dependent Claim 21 words
A fixing apparatus according to claim 1, wherein said limiting means adjustably restrains the inter-axis distance between said two rotary members.
Claim 7
Dependent Claim 133 words
A fixing apparatus of the type in which a nip pressure is applied to a toner image bearing member between a pair of rotary members to fix the toner image onto the bearing member, said fixing apparatus comprising: a first rotary member; a second rotary member disposed to nip a toner image bearing member between said first and second rotary members; a first pressing means acting, at a transporting reference side of the toner image bearing member, on said first and second rotary members; and a second pressing means acting on the opposite side of said first and second rotary members; wherein when said toner image bearing member enters between said first and second rotary members, the acting force of said first pressing means is larger than that of said second pressing means.
Claim 8
Dependent Claim 133 words
A fixing apparatus of the type in which a nip pressure is applied to a toner image bearing member between a pair of rotary members to fix the toner image onto the bearing member, said fixing apparatus comprising: a first rotary member; a second rotary member disposed to nip a toner image bearing member between said first and second rotary members; a first pressing means acting, at a transporting reference side of the toner image bearing member, on said first and second rotary members; and a second pressing means acting on the opposite side of said first and second rotary members; wherein when said toner image bearing member enters between said first and second rotary members, the acting force of said first pressing means is larger than that of said second pressing means.
Claim 9
Dependent Claim 59 words
A fixing apparatus according to claim 6, wherein said apparatus comprising first support means rotatably supporting said first rotary member and second support means rotatably supporting said second rotary member, and said first pressing means has a fixing member to fix said first and second support means at the side of transporting reference for said toner image bearing member.
Claim 10
Dependent Claim 45 words
A fixing apparatus according to claim 6, wherein said first pressing means and second pressing means comprising a compression spring, respectively, and the spring constant of the spring of the first pressing means is larger than that of the spring of the second pressing means.
Claim 11
Dependent Claim 47 words
A fixing apparatus according to claim 6, wherein said first pressing means has a plurality of compression springs and said second pressing means has at least one compression spring, the number of springs of the first pressing means being larger than that of the second pressing means.
Claim 12
Dependent Claim 39 words
A fixing apparatus according to claim 6, wherein said first and second pressing means comprise compression springs, respectively, and the force on the rotary members by said first pressing means is larger than that of the second pressing means.
Claim 13
Dependent Claim 40 words
A fixing apparatus according to claim 6, wherein said first pressing means has a compression spring, which is in its natural length in non-fixing state and is compressed when said toner image bearing member enters between said two rotary members.
Claim 14
Dependent Claim 40 words
A fixing apparatus according to claim 6, wherein said first pressing means comprises an assembly consisting of pressing roller acting on said first rotary member and a compression spring urging the pressing roller to contact with said first rotary member.
Claim 15
Dependent Claim 77 words
A fixing apparatus according to claim 12, wherein said first rotary member has both ends of which diameters being somewhat larger than the diameter of the roller within fixing operation region, and these both ends and said second rotary member are in the closely contacting state, and the fixing operation regions of said first rotary member and second rotary member, respectively, form a clearance therebetween which is less than the thickness of said toner image bearing member.
Claim 16
Dependent Claim 40 words
A fixing apparatus according to claim 13, wherein the pressing roller of said assembly is arranged always to contact the first rotary member in its fixing operation region at the side of transporting reference for said toner image bearing member.
Claim 17
Dependent Claim 38 words
A fixing apparatus according to claim 13, wherein the pressing roller of said assembly is arranged always to contact the first rotary member at its end of the side of transporting reference for said toner image bearing member.

References Cited (Backward Citations)

US3854975A Cited
US4022122A Cited
US4188109A Cited
US4104963A Cited
US4154575A Cited
US4235166A Cited
US4200389A Cited
US4258372A Cited
US4341458A Cited
US4356764A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-04-03 1987-10-03 1988-04-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-04-03 1991-10-03 1992-04-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-04-03 1995-10-03 1996-04-03 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag