摘要:
A sheet feed roller prolonging sustainability of sheet feeding capability even if crushed powders are scattered. The sheet feed roller comprises a hub and an elastic layer provided on an outer peripheral surface of the hub, wherein plural grooves axially extend at specific intervals circumferentially on an outer peripheral surface of the elastic layer, a textured surface comprising mountain portions and a valley portion is formed on an outer peripheral surface of the elastic layer except for the grooves, and on bottom surfaces and wall surfaces of the grooves, a ratio of a total area of the bottom surfaces of the grooves to a total area of the outer peripheral surface of the elastic layer except for the grooves is 10% to 20%.
摘要:
A fluid-filled cylindrical elastic mount having an elastic body between an inner and an outer sleeve, a movable member movably disposed in a pressure-receiving chamber defined by the outer sleeve and the elastic body, a rigid member cooperating with the outer sleeve to define a space diametrically opposite to the pressure-receiving chamber in a load-receiving direction of the mount, and a partition member having a flexible portion and dividing the space into two sections one of which serves as an equilibrium chamber disposed diametrically opposite to the pressure-receiving chamber. The movable member and the inner surface of the pressure-receiving portion define a fluid resonance portion for isolating high-frequency vibrations. An orifice passage is spirally formed for fluid communication between the pressure-receiving and equilibrium chambers, for damping low-frequency vibrations.
摘要:
A method of manufacturing a fluid-filled elastic mount including an elastic body connecting an inner and an outer sleeve, and having a pressure-receiving and an equilibrium chamber which are filled with a non-compressible fluid and communicate with each other through an orifice. The method includes preparing an inner unit having an intermediate sleeve connected to the inner sleeve by the elastic body, and a pocket formed in the elastic body such that the pocket is open through the intermediate sleeve and has an axial dimension defined by axially opposite side walls of the elastic body. The method further includes placing the inner unit within a mass of the fluid, and press-fitting the outer sleeve on the inner unit so as to provide the pressure-receiving chamber filled with the fluid, while applying an axial force to at least one of the side walls in the axial direction of the mount, to thereby cause elastic deformation of the side wall or walls so as to expand into the pocket. The axial force is removed from the side wall or walls to increase the volume of the pressure-receiving chamber and thereby reduce the volume of the equilibrium chamber.
摘要:
A sheet feeding roller, available at a lower cost, having lower hardness with securing both abrasion resistance and sustainability of friction coefficient. The sheet feeding roller comprises a hub, an inner layer provided on an outer peripheral surface of the hub, and an outer layer provided on an outer peripheral surface of the inner layer, the inner layer and the outer layer are formed by an unfoamed cured body of thermosetting urethane rubber wherein the outer layer is harder than the inner layer.
摘要:
A toner supply roll including a cylindrical soft polyurethane sponge structure which is integrally formed on a metal shaft and which has a hardness of not higher than 350 g, a network of cells, and a skin layer having openings which are open in its outer circumferential surface and which communicate with respective radially outermost ones of the cells located adjacent to the skin layer, wherein the openings have a size of 100-800 &mgr;m, and a total area percent of at least 20% of the total area of the outer circumferential surface of the skin layer, and the sponge structure has a plurality of helical protrusions formed on the outer circumferential surface of the skin layer so as to extend helically about an axis of the sponge structure, the helical protrusions being arranged in a circumferential direction of the sponge structure, so as to form a plurality of helical recesses each interposed between adjacent ones of the helical protrusions, so that helical protrusions and recesses cooperate to define a toothed profile in transverse cross section in a plane perpendicular to the axis.
摘要:
A sheet feeding roller, available at a lower cost, having lower hardness with securing both abrasion resistance and sustainability of friction coefficient. The sheet feeding roller comprises a hub, an inner layer provided on an outer peripheral surface of the hub, and an outer layer provided on an outer peripheral surface of the inner layer, the inner layer and the outer layer are formed by an unfoamed cured body of thermosetting urethane rubber wherein the outer layer is harder than the inner layer.
摘要:
A method for producing a sheet transport roll with an appropriate cure and short curing time so as to form a textured roll surface without defects caused by air inclusion or the like and thereby obtain a high friction coefficient, and also an excellent abrasion resistance. The method comprises the steps of: providing a mold having an inner textured surface and containing a shaft 1 for the roll; filling a urethane composition into the mold; and forming a urethane roll portion 2 on an outer periphery of the shaft by hardening the urethane composition, the urethane composition comprising: (A) a polyether polyol blend containing polytetramethyleneether glycol (PTMG) and polypropylene glycol (PPG) in a weight ratio of PTMG/PPG=99/1 to 50/50; (B) a polyisocyanate; (C) a chain lengthening agent; (D) a plasticizer; and (E) a diazabicyclo amine salt.
摘要:
A toner supply roll including a cylindrical soft polyurethane sponge structure formed on an outer circumferential surface of a metal shaft by foam molding of a polyurethane material in a mold cavity of a mold. The sponge structure having hardness of 350 g or lower includes a skin layer having a network of cells and openings open in its outer circumferential surface and communicating with respective ones of the cells located adjacent to the skin layer, such that the openings are substantially aligned with central portions of the respective ones of the cells in axial and circumferential directions of the sponge structure. Each opening has a size of 100-800 .mu.m, and a total area of the openings is at least 20% of the total surface area of the skin layer. The sponge structure has a plurality of protrusions formed on the outer circumferential surface of the skin layer so as to extend linearly or helically in the axial direction of the sponge structure. The protrusions have a height of 20-3000 .mu.m and are arranged in a circumferential direction of the sponge structure with a pitch of 300-3000 .mu.m, so that the skin layer is provided with recesses each interposed between the adjacent protrusions. Methods of producing the roll are also disclosed.
摘要:
A conductive roll including a conductive shaft, a conductive rubber foam layer formed on an outer circumferential surface of the conductive shaft, and a semi-conductive solid rubber layer formed on an outer circumferential surface of the conductive rubber foam layer. The conductive roll is produced by forming a cylindrical laminar body which gives the conductive rubber foam layer and semi-conductive solid rubber layer, and simultaneously vulcanizing and foaming the laminar body in a mold in which the conductive shaft is placed in position.
摘要:
A urethane composition for making a sheet transport roll, the composition comprising: (A) a polyether polyol blend containing polytetramethyleneether glycol (PTMG) and polypropylene glycol (PPG) in a weight ratio of PTMG/PPG=99/1 to 50/50; (B) a polyisocyanate; and (C) a chain lengthening agent; the urethane composition in a cured state having a hardness of not smaller than 40, and a crosslinking density of 0.15 to 0.8 mmol/cm3 or an allophanate bond concentration of 0.03 to 0.07 mmol/g.