Sheet feeding or delivering – Feeding – Separators
Reexamination Certificate
1999-12-29
2001-08-14
Bollinger, David H. (Department: 3651)
Sheet feeding or delivering
Feeding
Separators
C271S119000
Reexamination Certificate
active
06273415
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a member for office machines. More particularly, the present invention pertains to a member for office machines which has a high friction coefficient, and is well suited for use in electrophotographic equipment and electrostatic recording equipment such as copying machines, laser printers and facsimile equipment, and further for use, as a paper feeding member, in machinery and equipment having a variety of paper feeding mechanisms such as ink-jet printers, automatic teller machines (ATM) money exchange machines, counting machines, automatic vending machines and cash dispensers (CD).
2. Description of the Related Arts
There is employed a member for office machines such as a roller and a belt in electrophotographic equipment and electrostatic recording equipment such as copying machines, laser printers and facsimile equipment, and further in such equipment as electrifying equipment, transfer equipment, developing equipment, deelectrifying equipment, paper feeding equipment and cleaning equipment.
Of these members, the paper feeding member which feeds sheets of paper by taking advantage of friction of a rubber roller or the like, is required to have excellent paper feeding characteristics, antifouling properties against paper, films and photographic printing paper, favorable durability and the like properties. Thus there have been proposed paper feeding members with various shapes and/or constructional materials.
There have heretofore been employed, for the aforesaid paper feeding members, vulcanized rubber such as silicone rubber, polyurethane rubber, styrene/butadiene rubber, butadiene rubber and ethylene/propylene rubber. In addition, attention has been paid in recent years to thermoplastic elastomers, which have come into use in combination with a softening agent.
Moreover, there has recently been brought into use, a paper feeding member in which a rubbery elastic body layer is installed on the peripheral surface of a core body having a cross-section in the form of a segment (including the form of spherical roller) or an eccentric core body.
In the case where the aforesaid paper feeding member is rotated, there are formed both a portion out of contact with paper sheets and a portion in contact with paper sheets. The paper feeding is carried out by the friction between the rubbery elastic body layer and the paper sheets when the peripheral surface of the layer comes in contact with the paper sheets. On the other hand, when the peripheral surface of the layer is out of contact with the paper sheets, the paper feeding member runs idle, thereby failing to feed paper sheets. The above-mentioned paper feeding member having such a feeding mechanism is imparted with excellent paper feeding characteristics including the capability of preventing double feeding and steadily feeding paper sheets.
In order that the above-mentioned paper feeding member may maintain stable paper feeding characteristics by taking advantage of friction of a rubbery elastic body layer, it is required to minimize variation in the friction coefficient thereof with the lapse of time (that is, an increase in the number of paper feeding times).
In general, however, the paper feeding member composed of the foregoing materials frequently brings about such an unfavorable circumstance that powders of silica, calcium carbonate, etc. and/or fibrous paper powders adhere to the surfaces of the paper feeding member during use, whereby the friction coefficient is lowered, thus making it impossible to steadily feed paper sheets. The aforesaid disadvantage tends to frequently occur particularly at the time of using reclaimed paper or art paper to be used for carrying out high quality printing.
For the purpose of preventing such disadvantage and inconvenience, there have heretofore been adopted several methods in which (1) the surface layer of the paper feeding member is abraded at every time of paper feeding so that the friction coefficient of the surface approaches the initial value; (2) a convex portion is provided on the surface of the member so as to impart a driving force to paper sheets; (3) a material having a high friction coefficient is used as the material for the member so that a moderate friction coefficient and paper sheet transport capacity are preserved even after the lowering of the friction coefficient due to the adhesion of paper powders and the like; (4) the tacky adhesion of the member surface is suppressed so as to alleviate the adhesion of paper powders.
Nevertheless at the present time, the method (1) brings about the problem that the capacities of paper feeding and transport are lowered and further, the service life of the member itself is inevitably shortened; and the foregoing methods (2) to (4) fails to exert sufficiently satisfactory working effect.
SUMMARY OF THE INVENTION
Under such circumstances, a general object of the present invention is to provide a member for office machines which is used as a paper feeding member capable of stable paper feeding in various equipment having a variety of paper feeding mechanisms. Other objects of the present invention will be obvious from the text of this specification hereinafter disclosed.
In such circumstance, intensive research and investigation were accumulated by the present inventors in order to achieve the above-mentioned objects, that is, to develop a paper feeding member capable of stable paper feeding. As a result, it has been found that by equipping the member with an annular elastic body on the peripheral surface of a core body so that the expansion rate of said annular elastic body falls within a specific range, it is made possible to enhance the friction coefficient of the body portion in contact with paper sheets without appreciably lowering the abrasion resistance thereof, maintain a moderate friction coefficient even after the lowering thereof due to the adhesion of paper powders with the lapse of time, and thus preserve paper sheets transport capacity. It has also been found that by providing the annular elastic body having different thickness in part so that the friction coefficient of the portion thereof in contact with the paper sheets differs in part, it is made possible to enhance the paper sheets transport capacity at the portion having a higher friction coefficient, and further to enhance paper sheets releasability at the portion having a lower friction coefficient, whereby a paper feeding member having excellent functions is obtained. The present invention has been accomplished by the foregoing findings and information.
That is to say, the present invention provides a member for office machines which comprises a core body and an annular elastic body installed on the peripheral surface thereof, characterized in that the expansion rate of said annular elastic body E(%) falls within the range of 5 to 30%, when expressed by the formula
E(%)={(d
1
−d
2
)/d
2
}×100
wherein d
1
in mm is the diameter of the core body with the proviso that in the case where the core body is in the form of a roller or odd-shaped, a longest portion in its cross-section is regarded as the diameter; and d
2
in mm is the inside diameter in mm of the annular elastic body before being installed on the peripheral surface of said core body.
The term “a member for office machines” as used herein is the general concept including any member for electrophotographic equipment and electrostatic recording equipment, and any member for equipment having a variety of paper feeding mechanisms such as ink-jet printers, automatic teller machines (ATM), money exchange machines, counting machines, automatic vending machines and cash dispensers (CD).
REFERENCES:
patent: 4664252 (1987-05-01), Galbraith
patent: 6032943 (2000-03-01), Yabushita et al.
patent: 6139006 (2000-10-01), Asada
Ando Yukio
Tengo Yuichiro
Bollinger David H.
Bridgestone Corporation
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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