Description PAPER FEEDING ROLLER FOR A SHREDDER

Technical Field

[1] Embodiments relate to a shredder.

Background Art

[2] A shredder is a device for cutting documents into small pieces to prevent the leakage of expired documents.

[3] Shredders are classified into a manual paper-feed type and an automatic paper-feed type.

[4] Fig. 1 is a cross-sectional view illustrating a shredder disclosed in Korean Patent

Application No. 10-2005-0013275 invented and filed by the applicant of the present disclosure.

[5] Referring to Fig. 1, the shredder includes a case 1 forming an exterior of the shredder, a driving motor 2 disposed in the case 1 and generating a driving force, a connection part 3 for transmitting a driving force of the driving motor 2 to a proper place, a cutter side connection gear 4 connected to the connection part 3 for transmitting a driving force to a couple of cutters 5, and a feed side connection gear 6 connected to the connection part 3 for transmitting a driving force to a plurality of paper-feed roller 7.

[6] In detail, an automatic feed side includes a paper-feed tray 11 on which a plurality of paper sheets P are placed, a pressing part 12 placed under the paper-feed tray 11 for pushing up the paper sheets P placed on the paper-feed tray 11, a pressing spring 13 elastically pushing up the pressing part 12, and the paper- feed rollers 7 disposed on the paper-feed tray 11 for feeding down the paper sheets P.

[7] An automatic feed sensor 9 for sensing whether paper sheets are placed on the paper-feed tray 11 is disposed at a front end of the paper-feed tray 11. The automatic feed sensor 9 may be a contact sensor for sensing paper sheets or may be an optical sensor for sensing a paper- feed state by detecting whether a paper sheet blocks light transmittance.

[8] In addition, in order to sense a paper sheet that is manually fed, a manual feed sensor 10 is disposed at a front end of an input portion of a manual feed part to sense the paper sheet. When the feeding of paper sheets to be shredded is sensed by the automatic feed sensor 9 or the manual-feed sensor 10, the driving motor 2 is operated to start the cutters 5 and the paper-feed rollers 7.

[9] The paper feed rollers 7 are fixed to a roller shaft (refer to 15 of Fig. 2), and feed protrusions 8 are disposed on at least one portion of an outer circumference of each

paper-feed roller 7. The feed protrusions 8 pick a predetermined number of paper sheets at a time to feed them.

[10] While the connection part 3 in Fig. 1 includes a predetermined number of gears, any other connection member such as a belt may be used.

[11] Referring to the aforementioned configuration, the operation and effect of the shredder will now be described in detail.

[12] In the automatic paper-feed type, an automatic operation of shredding paper sheets will now be described in detail. When paper sheets are placed on the paper-feed tray 11, the automatic feed sensor 9 senses the feeding of the paper sheets and thus, the driving motor 2 starts to operate.

[13] When the paper sheets are placed on the paper feed tray 11, the pressing spring 13 generates a force that pushes up the pressing part 12 rotating around a hinge point located in a left portion, thereby making the paper sheets come in contact with the paper feed rollers 7.

[14] When the paper sheets are pushed up by the pressing part 12, at least the top paper sheets comes in contact with the paper feed rollers 7, and torque of the driving motor 2 is transmitted to the paper feed rollers 7 through the connection part 3 and the feed side connection gear 6, thereby rotating the paper feed rollers 7. In addition, the feed protrusions 8 are spaced a predetermined distance from each other on an outer circumference of each paper-feed roller 7, so that the paper feed rollers 7 can pick a certain number of paper sheets or more at a time to feed them.

[15] Here, a pointed tip is formed at the end of each supply protrusion 8 to convey the paper sheets. In addition, a ledge 14 is formed to prevent the paper sheets from moving downward. Thus only the predetermined number of paper sheets picked by the feed protrusions 8 are forcibly pushed to pass over the ledge 14.

[16] As a matter of course, since the pressing part 12 keeps moving the paper sheets upward, the remains of the paper sheets is continuously fed after the predetermined number of paper sheets or more are fed.

[17] Thereafter, the paper sheets having passed over the ledge 14 are fed to the cutters 5 to be shredded into small pieces.

[18] In a manual paper- feed type, a manual operation of shredding paper sheets will now be described in detail. When paper sheets are fed to a manual feed part, the paper sheets are sensed by the manual feed sensor 10, and then the driving motor 2 is driven. Then, torque of the driving motor 2 is transmitted to the cutters 5 through the connection part 3 and the cutter side connection gear 4. The paper sheets are caught in a gap between the couple of cutters 5 to be shredded. It will be easily appreciated that the cutters 5 have a circular section and includes a plurality of blades.

[19] When the paper sheets are caught in the gap between the cutters 5, the cutters 5

rotates at a relatively fast speed, thereby quickly shredding the paper sheets into small pieces without the paper-feed roller 7.

[20] It will be easily appreciated that different gear ratios allow the cutters 5 to rotate slightly faster than the paper-feed rollers 7 does, and thus the paper sheets are quickly shredded without the paper-feed roller 7.

[21] In addition, if an excessive number of paper sheets caught in the gap between the cutters 5 causes a motor overload, the caught paper sheets are detected by checking the decrease of a motor speed and/or the increase of power consumption.

[22] Furthermore, the excessive number of paper sheets caught in the gap between the cutters 5 are removed by a temporary pause and a predetermined number of reverse rotations of the driving motor 2. Thereafter, the driving motor 2 is stopped. This operation facilitates the removal of the excessive number of paper sheets; prevents malfunctions of the shredder due to the motor overload; and increases the life span of the shredder.

[23] Fig. 2 is a front view illustrating a plurality of paper-feed rollers 7.

[24] Referring to Fig. 2, provided are the paper-feed rollers 7 for feeding a predetermined number of paper sheets, a plurality of feed protrusions 8 disposed in a central portion of each paper- feed roller 7, and a roller shaft 15 for rotating the paper feed rollers 7 at a constant velocity. Although not shown, it will be easily appreciated that a gear engaged with the feed side connection gear 6 of Fig. 1 is fixed to at least one side of the roller shaft 15.

[25] The paper- feed rollers smoothly feed the paper sheets and prevent the feeding of the paper sheets from being performed out of a feed direction.

[26] Fig. 3 is a cross-sectional view illustrating a paper-feed roller 7 different from that of Fig. 2. Fig. 4 is a cross-sectional view taken along line I-F of Fig. 3.

[27] Referring to Figs. 3 and 4, the paper-feed roller 7 has a circular shape; a groove 16 having a predetermined width is formed in an outer circumference of the paper-feed roller 7; and sharp feed protrusions 8 protrude from the groove 16. The feed protrusions 8 completely feed and guide paper sheets in comparison with a single feed protrusion.

[28] Meanwhile, it is desirable that the feed protrusions 8 of the paper-feed roller 7 feed a predetermined number of paper sheets or more to the cutters 5 of Fig. 1 at a time. However, the feed protrusions 8 may tear the paper sheets during the feeding of the paper sheets.

[29] In here, the torn paper sheets are further torn by rotations of the paper- feed roller 7 until the paper-feed roller 7 cannot pick the torn paper. As a result, the torn paper sheets are not fed to the cutters 5.

Disclosure of Invention

Technical Problem

[30] Embodiments provide a paper-feed roller of a shredder for smoothly feeding a predetermined number of paper sheets or more to cutters although the paper sheets are torn by a paper- feed protrusion. Technical Solution

[31] In one embodiment, a paper- feed roller includes a rotatable roller shaft, a rotatable roller member coupled to the roller shaft, a friction-feed member on an outer circumference of the roller member, and a feed protrusion coupled to the roller member, the feed protrusion protruding a predetermined amount from the friction-feed member.

[32] In another embodiment, a paper-feed roller includes a rotatable roller shaft, a plurality of rotatable roller members coupled to the roller shaft, a friction-feed member on an outer circumference of at least one of the roller members, and a feed protrusion coupled to at least one of the roller members.

Advantageous Effects

[33] According to an embodiment, a paper-feed roller of a shredder smoothly feeds a predetermined number of paper sheets or more to cutters although the paper sheets are torn by a paper- feed protrusion.

Brief Description of the Drawings

[34] Fig. 1 is a cross-sectional view illustrating a shredder disclosed in Korean Patent

Application No. 10-2005-0013275 invented and filed by the applicant of the present disclosure.

[35] Fig. 2 is a front view illustrating a paper-feed roller of a related art.

[36] Fig. 3 is a cross-sectional view illustrating a paper-feed roller different from that of

Fig. 2.

[37] Fig. 4 is a cross-sectional view taken along line I-F of Fig. 3.

[38] Figs. 5 to 7 are views illustrating paper-feed rollers of a shredder according to a first embodiment. [39] Fig. 8 is a side view illustrating a paper-feed roller according to a second embodiment. [40] Fig. 9 is a side view illustrating a paper-feed roller according to a third embodiment. [41] Fig. 10 is a side view illustrating a paper- feed roller according to a fourth embodiment. [42] Fig. 11 is a side view illustrating a paper- feed roller according to a fifth embodiment. [43] Fig. 12 is a view illustrating paper-feed rollers according to a sixth embodiment.

Best Mode for Carrying Out the Invention

[44] Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

[45] Figs. 5 to 7 are views illustrating four paper- feed rollers 100 of a shredder according to a first embodiment.

[46] In detail, Figs. 5 and 6 are views illustrating a structure of the paper-feed rollers

100, and Fig. 7 is a view illustrating an assembly of a roller shaft 60 and the paper- feed rollers 100.

[47] Referring to Figs. 5 to 7, each paper-feed roller 100 includes a first and second roller members 31 and 51, a first and second friction-feed members 32 and 52, and two feed protrusions 40 disposed between the first and second roller members 31 and 51.

[48] The first roller member 31 includes a first roller shaft hole 34 through which the roller shaft 60 is inserted, first screw holes 33 through which screws (not shown) go so as to assemble the first and second roller members 31 and 51, guide protrusions 35 guiding the assembling, and six first receiving portions 36 for receiving the feed protrusions 40.

[49] Meanwhile, the second roller member 51 includes a second roller shaft hole 54 through which the roller shaft 60 is inserted, second screw holes 53 through which the screws go so as to assemble the first and second roller members 31 and 51, guide holes 55 guiding the assembling, and six second receiving portions 56 for receiving the feed protrusions 40.

[50] The first and second roller shaft holes 34 and 54 have a polygonal shape to rotate the first and second roller member 31 and 51 according to rotation of the roller shaft 60. In the embodiment, the first and second roller shaft holes 34 and 54 have a hexagonal shape. For example, the first and second roller shaft holes 34 and 54 may have any shape such as a tetragonal shape or a pentagonal shape.

[51] In addition, while the roller shaft 60 is inserted into the first and second roller shaft holes 34 and 54 having the hexagonal hole in the embodiment, the roller shaft 60 may be coupled with the paper- feed rollers 100 using an adhesive, or a bolt and a nut.

[52] As a result, the first and second roller shaft holes 34 and 54 are fitted on the roller shaft 60 to be rotated according to the rotation of the roller shaft 60.

[53] The first and second screw holes 33 and 53 are formed to fix the first and second roller members 31 and 51. First, the screws go through the first screw hole 33 to fix the first and second roller members 31 and 51 firmly.

[54] While the screws are used in the embodiment, an adhesive may be used to couple the first and second roller members 31 and 51.

[55] Each guide hole 55 receives each guide protrusion 35. The guide protrusions 35 and

the guide holes 55 guide the assembling of the first and second roller members 31 and 51 in a predetermined direction. Since the first and second roller members 31 and 51 support the feed protrusions 40, the first and second roller members 31 and 51 should be assembled in the predetermined direction.

[56] Meanwhile, while the feed protrusions 40 are fixed by the first and second roller members 31 and 51 in the embodiment, the feed protrusions 40 may be fixed using an adhesive. Also, one of the first and second roller members 31 and 51 may have a receiving portion for receiving the feed protrusions 40, and the other may have no receiving portion. Thus, it is not necessary to assemble the first and second roller members 31 and 51 in the predetermined direction. Furthermore, the guide protrusions 35 and the guide holes 55 are not required.

[57] While the two feed protrusions 40 are provided in the embodiment, the number of the feed protrusion 40 may be various.

[58] While the feed protrusions 40 are formed of metal, the feed protrusions 40 may be formed of stainless steel including nickel and chrome. The feed protrusions 40 are coupled to the first and second roller members 31 and 51 to protrude from the first and second friction feed members 32 and 52 by a height ranging from 0.5 mm to 2.0 mm.

[59] The first and second friction feed members 32 and 52 are formed of rubber such as

Ethylene Propylene Diene Monomer (EPDM).

[60] The first and second friction feed members 32 and 52 convey paper sheets that are torn or not conveyed by the feed protrusions 40. A plurality of protrusions 37 and 57 protrude from the first and second friction feed members 32 and 52 by a height ranging from 0.1 mm to 0.5 mm, respectively. The protrusions 37 and 57 are also formed of rubber.

[61] For example, the first and second friction feed members 32 and 52 may have a smooth surface.

[62] Fig. 8 is a side view illustrating a paper-feed roller according to a second embodiment. Descriptions similar to those in the first embodiment will be omitted.

[63] A first roller member 31 includes a first friction-feed member 32. A plurality of protrusions are formed on two portions of the first friction-feed member 32. Two feed protrusions 40 are coupled to the first roller member 31.

[64] Although a roller shaft 60 and a configuration of a second roller member 51 are not shown, it will be appreciated that the second roller member 51 has a configuration corresponding to that of the first roller member 31 according to the first embodiment.

[65] Fig. 9 is a side view illustrating a paper-feed roller according to a third embodiment. Descriptions similar to those in the first embodiment will be omitted.

[66] A first roller member 31 includes a first friction-feed member 32. Two feed protrusions 40 are coupled to the first roller member 31. In the third embodiment,

protrusions are not formed on the first friction-feed member 32.

[67] Although a roller shaft 60 and a configuration of a second roller member 51 are not shown, it will be appreciated that the second roller member 51 has a configuration corresponding to that of the first roller member 31 according to the first embodiment.

[68] Fig. 10 is a side view illustrating a paper- feed roller according to a fourth embodiment. Descriptions similar to those in the first embodiment will be omitted.

[69] A first roller member 31 includes a first friction-feed member 32. A plurality of protrusions are formed on a portion of the first friction-feed member 32. A feed protrusion 40 is coupled to the first roller member 31.

[70] Although a roller shaft 60 and a configuration of a second roller member 51 are not shown, it will be appreciated that the second roller member 51 has a configuration corresponding to that of the first roller member 31 according to the first embodiment.

[71] Fig. 11 is a side view illustrating a paper- feed roller according to a fifth embodiment. Descriptions similar to those in the first embodiment will be omitted.

[72] A first roller member 31 includes a first friction-feed member 32. A plurality of protrusions are formed on three portions of the first-friction feed member 32. Three feed protrusions 40 are coupled to the first roller member 31.

[73] Although a roller shaft 60 and s configuration of a second roller member 51 are not shown, it will be appreciated that the second roller member 51 has a configuration corresponding to that of the first roller member 31 according to the first embodiment.

[74] Fig. 12 is a view illustrating two second paper- feed rollers 200 and two third paper- feed rollers 300 according to a sixth embodiment. Descriptions similar to those in the first embodiment will be omitted.

[75] The paper- feed rollers 200 and 300 are coupled with a roller shaft 60.

[76] The second paper-feed rollers 200 includes first friction-feed members 32 formed on first roller members 31 , and second friction-feed members 52 formed on second roller members, and feed protrusions 40 coupled to the first roller member 31 and the second roller members.

[77] The third paper-feed rollers 300 include the first friction-feed members 32 formed on the first roller members 31, and the second friction-feed members 52 formed on the second roller members, protrusions 37 formed on the first friction-feed members 32, and protrusions 57 formed on the second friction-feed members 52. The feed protrusions 40 are not included in the third paper-feed rollers 300.

[78] The second and third paper-feed rollers 3 are alternately disposed. While the number of the paper- feed rollers 200 and 300 is four in the sixth embodiment, the number may be various.

[79] As described above, the paper- feed roller according to the embodiments is rotated by the roller shaft to feed the predetermined number of paper sheets to the cutters.

[80] The paper-feed roller includes the rotatable roller member coupled to roller shaft, the feed protrusion coupled to the roller member, and the friction-feed member coupled to the roller member. [81] The friction-feed member may include the protrusion. The feed protrusion and the friction-feed member may be coupled to the same roller member. Alternatively, the feed protrusion may be coupled to any one of the roller members, and the friction-feed member may be coupled to another of the roller members. [82] In other words, the paper-feed roller for feeding paper sheets includes the feed protrusion and the friction-feed member including the protrusion, thereby [83] Therefore, the paper-feed roller feeds a predetermined number of paper sheets or more to cutters using the feed protrusion. Furthermore, although the paper sheets are torn by the feed protrusions, the paper-feed roller smoothly feeds the paper sheets using the friction-feed member.

Industrial Applicability [84] The embodiments can be applied to a shredder.