Heat and pressure fuser
AssigneeXerox Corporation
InventorsDaniel L. Morris, David A. Bartman, Albert E. Andrews, Emilio J. Giuseppetti, Paul M. Achtziger, Paul J. Rowe, Donald L. Pease
Life of this patent
Estimating the term…
Abstract
A heat and pressure fuser includes a thin web which is wrapped around a portion of a heated fuser roll to form a fusing area. The web contacts the fuser over a relatively short wrap angle to reduce torque required to drive the fuser roll, thereby enabling a higher process speed. Fusing efficiency is maintained by use of a biasing mechanism which increases the pressure applied to the web both the entrance and exit areas of the fuser.
Claims7
A heat and pressure fusing system for fusing a toner image on a copy sheet having a leading and trailing edge comprising:
- a rotatable heated fuser roll,
- a thin web in pressure contact with the fuser roll along a wrap angle of less than 70.degree. of the total arc circumference of the fuser roll, said wrap angle defining the area in which the toner image is fused, and
- web biasing means for maintaining the web in contact with the roll surface at at least two pressure differentials along said wrap angle area, said fusing system further including an entrance nip formed at the roll and web interface for engaging the leading edge of the copy sheet and wherein said web biasing means includes a first flexible blade member mounted so as to apply a first biasing pressure to said web at a point beginning at said entrance nip and extending over an area A of the total wrap angle area, and a second flexible blade member mounted so as to apply a second biasing pressure to said web across an area B of the wrap angle area separated from area A and wherein said first and second pressures applied by said first and second blade members are within a pressure range of 16 to 22 pounds.
A large document copying machine in which a photoconductive member is rotated at a process speed of between 2 and 3 inches per second (ips), said photoconductive member having a width between 12 and 36 inches and passing through a plurality of xerographic stations including a large document exposure station, a developer station, a transfer station, and a fusing station, the fusing station comprising a heat and pressure fusing system for fusing a toner image on a copy sheet having a leading and trailing edge, said fusing system comprising:
- a rotatable heated fuser roll,
- a thin web in pressure contact with the fuser roll along a wrap angle of less than 70.degree. of the total arc circumference of the fuser roll, said wrap angle defining the area in which the toner image is fused, and
- web biasing means for maintaining the web in contact with the roll surface at at least two pressure differentials along said wrap angle area, said fusing system further including an entrance nip formed at the roll and web interface for engaging the leading edge of the copy sheet and wherein said web biasing means includes a first flexible blade member mounted so as to apply a first biasing pressure to said web at a point beginning at said entrance nip and extending over an area A of the total wrap angle area, and a second flexible blade member mounted so as to apply a second biasing pressure to said web across an area B of the wrap angle area separated from area A and wherein said first and second pressures applied by said first and second blade members are within a pressure range of 16 to 22 pounds.
Dependencies are inferred from the claim text.