Pressure rollers for toner fusing station
AssigneeMinnesota Mining and Manufacturing Company
InventorOrville C. Haugen
Life of this patent
Estimating the term…
Abstract
A pressure roller and apparatus for pressure fixing imaging powder in an electrostatic duplicating machine, the apparatus comprising a pair of fixing rollers in pressure contact along a narrow band to define a nip. The fixing rollers are hollow cylindrical rollers with parallel longitudinal axes and are rotatably supported by pressure transfer rollers inside each fixing roller. The pressure transfer rollers in each fixing roller are rotatably supported by a shaft and housing. Pressure supplied by loading means at the ends of the shafts to pressure fix imaging powder to a substrate transported through the nip is distributed uniformly along the nip by the pressure transfer rollers without causing bending moments on the fixing rollers.
Claims15
A pressure fixing apparatus for pressure fixing a toner powder image to a substrate in an electrophotographic copying machine, which comprises:
- a pair of hollow cylindrical fixing rollers having their longitudinal axes parallel and coplanar, said fixing rollers each having an outer cylindrical surface and an inner cylindrical surface, said outer cylindrical surfaces being in pressure contact along a narrow band parallel to the axes of said fixing rollers to define a nip for pressure fixing toner powder to a substrate;
- and
- a drive assembly for rotating said fixing rollers and for rotatably supporting said fixing rollers in uniform pressure contact along said nip, said drive assembly comprising:
- pressure transfer rollers inside said fixing rollers for transferring driving torque to rotate said fixing rollers and for maintaining uniform pressure at said nip, each pressure transfer roller comprising walls defining:
- a hollow cylindrical body having a longitudinal axis defining the longitudinal axis of said pressure transfer roller;
- and
- a plurality of axially spaced cylindrical radial projections extending radially out from said cylindrical body, said radial projections having cylindrical peripheral surfaces coaxial with said longitudinal axis of said pressure transfer roller and having a diameter less than the diameter of said inner cylindrical surface of said fixing rollers, for pressure engagement with said inner cylindrical surface of said fixing roller;
- support means for engaging and transferring pressure and driving torque to said pressure transfer rollers and for rotatably supporting said pressure transfer rollers inside said fixing rollers so that said longitudinal axes of said pressure transfer rollers are in parallel alignment with said nip;
- loading means for urging said support means toward said nip, said loading means effecting pressure contact between said support means and said pressure transfer rollers and said fixing rollers thereby effecting desired pressure uniformly along said nip, and
- drive means for rotating said support means at a predetermined velocity, wherein said pressure contact together with rotation of said support means effects rolling contact between said support means and said pressure transfer rollers and between said pressure transfer rollers and said fixing rollers whereby rotation of said support means effects simultaneous rotation of said pressure transfer rollers and said hollow cylindrical rollers.
A pressure roller assembly comprising a hollow cylindrical roller and means for rotatably supporting said hollow cylindrical roller in pressure contact with a base surface,
- said hollow cylindrical roller having a longitudinal axis, an outer coaxial cylindrical surface and a plurality of coaxial inner cylindrical surfaces, said outer cylindrical surface contacting said base surface along a narrow band parallel to said longitudinal axis to define a nip, said means for rotatably supporting said hollow roller comprising:
- pressure transfer rollers inside said hollow cylindrical roller for transferring driving torque to rotate said hollow cylindrical roller and for maintaining uniform pressure at said nip, each pressure transfer roller comprising walls defining:
- a hollow cylindrical body having a longitudinal axis defining the longitudinal axis of said pressure transfer roller;
- and
- a plurality of axially spaced cylindrical radial projections extending radially out from said cylindrical body for pressure engagement with said inner cylindrical surfaces of said hollow cylindrical roller, said radial projections having cylindrical peripheral surfaces coaxial with said longitudinal axis of said pressure transfer roller and having a diameter less than the diameter of said inner cylindrical surfaces of said hollow cylindrical roller;
- support means for engaging and transferring pressure and driving torque to said pressure transfer rollers and for rotatably supporting said pressure transfer rollers inside said hollow cylindrical roller so that said longitudinal axes of said pressure transfer rollers are in parallel alignment with said nip;
- loading means for urging said support means toward said nip, said loading means effecting pressure contact between said support means and said pressure transfer rollers and pressure contact between said pressure transfer rollers and said hollow cylindrical rollers thereby effecting desired pressure uniformly along said nip, and
- drive means for rotating said support means at a predetermined velocity, wherein said pressure contact together with rotation of said support means effects rolling contact between said support means and said pressure transfer rollers and between said pressure transfer rollers and said hollow cylindrical roller so that rotation of said support means effects simultaneous rotation of said pressure transfer rollers and said hollow cylindrical roller.
Dependencies are inferred from the claim text.