Sheet feed roller and method of manufacturing the same

Abstract

The present invention provides a sheet feed roller in which, even when the height of a plurality of projections is high or a rotation angle ( alpha ) formed between the projections is small, punches do not interfere with the projections at the time of forming the projection and thus a grip force of the projections on a sheet can be increased at the time of carrying the sheet, and a method of manufacturing the same. Projections (4) formed on a circumferential surface of a roller portion (2) of the sheet feed roller comprise straight grain projections (5) whose projecting direction faces to the rotation direction of the roller portion (2), and reverse grain projections (6) that are formed in a direction opposite to the surfaces of the straight grain projections (5). The straight grain projections (5) are formed so as to be adjacent to each other in the axial direction of the roller portion (2), that is, in the direction of arrow (B) and are also formed in two or more rows in the circumferential direction of the roller portion (2), that is, in the direction of arrow (A). The reverse grain projections (6) are formed so as to be adjacent to each other in the axial direction of the straight grain projections (5) and are also formed in the circumferential direction.

Description

technical field [0001] The present invention relates to a sheet conveying roller used in a printing machine such as a printer, which can suitably convey a sheet such as recording paper held between the roller and the sheet conveying roller, and a method for manufacturing the same. Background technique [0002] As shown in FIG. 10, a conventional sheet conveying roller 21 has a cylindrical roller portion 22 made of metal, and a plurality of rollers are formed on the peripheral surface of the roller portion 22 in the circumferential direction and the axial direction at predetermined intervals and projecting heights. 23 protrusions. [0003] Such a conventional sheet conveying roller 21 is provided with, for example, a pressure roller 24 elastically biased by a coil spring (not shown) or the like on the peripheral surface of the roller portion 22 , and the pressure roller 24 is pressed between the roller portion 22 and the pressure roller 24 . A sheet 25 made of recording pape...

AI Technical Summary

Problems solved by technology

[0018] However, as shown in FIG. 12, for example, the angle α between the positive projection 23a adjacent to the circumferential direction and the rotation direction of the positive projection 23a is 6°. The head 27 interferes with the forward protrusion 23 formed in the front, thereby creating a problem of cutting off the top of the forward protrusion 23a formed in the front

[0019] Therefore, since it is necessary to lower the plurality of protrusions 23 to a height that does not interfere with the range of the punch 27 during the punching operation, or to increase the angle α in the direction of rotation, the number of protrusions 23 per unit area that sticks to the sheet 25 decreases. , resulting in the problem of reduced clamping force on the sheet 25

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