Photography – Fluid-treating apparatus – Having photographic medium feed
Reexamination Certificate
1999-06-07
2001-01-30
Rutledge, D. (Department: 2851)
Photography
Fluid-treating apparatus
Having photographic medium feed
C271S286000, C271S298000, C355S027000
Reexamination Certificate
active
06179495
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a photosensitive material discharging apparatus for transporting along a transport path and discharging a photosensitive material. More particularly, the invention relates to a photosensitive material discharging apparatus having a discharge section disposed downstream of a transport path for discharging a photosensitive material, a plurality of discharge roller pairs arranged in the discharge section for discharging the photosensitive material, and a plurality of transport roller pairs arranged on the transport path upstream of the discharge roller pairs.
2. Description of the Related Art
The above photosensitive material discharging apparatus is disclosed in U.S. Pat. No. 5,724,626, for example. The prior apparatus defines a transport path for transporting a photosensitive material emerging from a developing stage and a drying stage, to a loading conveyer for loading the material onto a sorter. This transport path includes a first transporting pinch roller mechanism having a plurality of pinch roller pairs, and a second transporting pinch roller mechanism disposed in an exit region of the transport path. The second pinch roller mechanism is capable of transporting the photosensitive material at a higher speed than the first pinch roller mechanism.
The pinch rollers constituting the first pinch roller mechanism are elongated rollers each extending perpendicular to a transport direction. The second pinch roller mechanism has large drive rollers, and small driven rollers opposed to the drive rollers, respectively. The drive rollers are mounted on roller shafts driven by a drive shaft through transmission gear mechanisms. Further, a torque limiter is disposed between a driven gear of each transmission gear mechanism and the roller shaft of each drive roller. The torque limiter is operable in response to a torque greater than a predetermined value to render the drive roller freely rotatable.
The photosensitive material introduced into this photosensitive material discharging apparatus is first transported by the first transporting pinch roller mechanism, at a transporting speed corresponding to a peripheral speed of the rollers of this roller mechanism, to a position adjacent an exit of the transport path. As the forward end of the photosensitive material advances into the second transporting pinch roller mechanism, the drive rollers of the second pinch roller mechanism would exert an effort to transport the material at a peripheral speed of the drive rollers. However, since the rear end of the photosensitive material is still engaged by the first transporting pinch roller mechanism, the torque limiters of the second transporting pinch roller mechanism operate to allow the photosensitive material to remain being transported at the transporting speed produced by the first transporting pinch roller mechanism. When the rear end of the photosensitive material is released from the first transporting pinch roller mechanism, the second transporting pinch roller mechanism accelerates the transport of the material to discharge it at high speed from the exit of the transport path.
The prior apparatus noted above has a disadvantage of requiring the torque limiters mounted in the second transporting pinch roller mechanism, which results in an increased cost. Moreover, where sheets of the photosensitive materials are discharged as a three-lane phase-staggered arrangement, the apparatus requires the number of torque limiters corresponding to the number of lanes. Then, the apparatus involves a very large cost. Where a plurality of torque limiters are used, variations among the torque limiters destabilize delivery of the sheets of the photosensitive material. This results in the sheets being discharged to varied, irregular positions.
SUMMARY OF THE INVENTION
This invention has been made having regard to the state of the art noted above, and its object is to provide a photosensitive material discharging apparatus which may be manufactured at reduced cost by dispensing with the torque limiters arranged at the photosensitive material outlet.
The above object is fulfilled, according to this invention, by a photosensitive material discharging apparatus for transporting along a transport path and discharging a photosensitive material, comprising a discharge section disposed downstream of the transport path for discharging the photosensitive material; a plurality of transport roller pairs arranged on the transport path upstream of the discharge section; and a discharge roller pair disposed in the discharge section for receiving the photosensitive material transported by the transport roller pairs and discharging the photosensitive material, the discharge roller pair having a first roller rotatable at a higher peripheral speed than the transport roller pairs, and a second roller disposed to pinch the photosensitive material with the first roller; wherein the second roller is freely rotatable to cause slippage between the first roller and the photosensitive material when the photosensitive material is pinched by both the transport roller pairs and the discharge roller pair, and to allow the photosensitive material to be transported by drive of the first roller when the photosensitive material is pinched only by the discharge roller pair.
With this construction, when the photosensitive material (e.g. photographic paper) is pinched by both the transport roller pair and discharging roller pair, the first roller of the discharge roller pair slips on a surface of the photosensitive material. Thus, no torque limiter is required, thereby contributing to a cost reduction.
In a preferred embodiment of this invention, the first roller is disposed to contact a back surface of the photosensitive material reverse to a front emulsion surface thereof. This feature is of advantage in that no damage is done to the emulsion surface on which images are formed.
In a further preferred embodiment of the invention, the first roller has a main roller body formed of plastic, and an element of high friction coefficient formed peripherally of the main roller body. This construction assures a reliable operation for discharging the photosensitive material.
In a further preferred embodiment of the invention, the second roller is supported by a support shaft vertically movable by a predetermined amount, the second roller contacting the first roller by gravity. This construction can absorb any load variations occurring while the photosensitive material is made to slip, to enhance the reliability of the discharging operation.
Other features and advantages of this invention will be apparent from the following description of an embodiment to be taken with reference to the drawings.
REFERENCES:
patent: 4796878 (1989-01-01), Nichelson et al.
patent: 5139247 (1992-08-01), Meschi
patent: 5193423 (1993-03-01), Bakker
patent: 5446520 (1995-08-01), Todoki
patent: 5724626 (1998-03-01), Todoki
patent: 427324A1 (1991-05-01), None
patent: 629915A2 (1994-12-01), None
Sugata Yoshihisa
Todoki Kenji
Fulbright & Jaworski LLP
Noritsu Koki Co., Ltd.
Rutledge D.
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