Scissors

Abstract

To provide scissors capable of suppressing as much as possible a defect that unintended breakage may appear at the tip of a cutting line when a paper sheet is cut.SOLUTION: A pair of scissors S includes a first scissor blade 1 as one scissor blade, a second scissor blade 2 as the other scissor blade, and a support shaft 3 for supporting the first and second scissor blades 1 and 2 to be relatively rotatable, wherein a recessed part 11w is formed on the front side of the support shaft 3 in a first blade piece 11 of the first scissor blade 1. The first edge line front portion e1f located in front of the recessed portion 11w extends substantially linearly between the recessed portion 112 and the most distal end point m of the first edge line e1, and is inclined at an angle of greater than 0 ° and less than or equal to 5 ° with respect to the imaginary straight line wi connecting the most distal end point m and the axial center point js of the support shaft 3.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to scissors. [Background technology]

[0002] BACKGROUND ART Various scissors for cutting paper sheets such as paper by user operation have been known (see, for example, Patent Document 1).

[0003] When cutting a sheet of paper using scissors, it is desirable that only a clean cut line be formed on the sheet of paper.

[0004] However, with conventional scissors, as illustrated in Figure 18, when a user moves the tips of the pair of blades to their final position (i.e., moves the pair of handles so that they come together and butt together, where the user can place their fingers), and cuts a sheet of paper P, it is easy for unintended tears, distortions, or other damage D to form near the tip ct of the cutting line c.

[0005] Needless to say, if a flaw such as an unintended tear or distortion occurs near the leading edge of the cutting line on a sheet of paper, the appearance of the sheet will be marred.

[0006] The inventors of the present application have conducted extensive research into the cause of the above-mentioned problem and have discovered that at least the above-mentioned problem is caused by excessive load being applied to the tip of the cutting line when one side of the paper sheet is pushed upward by the blade and the other side of the paper sheet is pushed downward by the blade. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-168495 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention has been made with the above-mentioned circumstances in mind, and aims to at least suppress the problem that, when paper sheets are cut, unintended tears, distortions, and other damage are likely to be formed near the tip of the cutting line. [Means for solving the problem]

[0009] That is, the present invention has the following configuration.

[0010] The invention described in claim 1 is a pair of scissors comprising one blade including a cutting edge with a cutting line formed thereon, the other blade including a cutting edge with a cutting line formed thereon, and a support shaft that supports the one and other blades so that they can rotate relative to one another so that the cutting edges of both blades slide to cut paper sheets, wherein a recess is formed in front of the support shaft in both or one of the blades, and the cutting edge located in front of the recess extends in an approximately straight line between the recess and the tip of the cutting edge, and is inclined at an angle greater than 0° and less than 5° with respect to an imaginary line connecting the axial center point of the support shaft and the tip of the cutting edge.

[0011] The invention described in claim 2 is the scissors described in claim 1, in which the position of the cutting edge located in front of the recess is set to be closer to the imaginary straight line than the inner edge of the cutting piece located behind the recess.

[0012] The invention described in claim 3 is the scissors described in claim 1, in which the one and other scissors blades have handle portions at the base ends of the blades with which the user's fingers engage, and the support shaft is arranged in front of the handle portions. [Effects of the Invention]

[0013] As described above, according to the present invention, it is possible to at least suppress the problem that when a sheet of paper is cut, unintended tears, distortions, or other damage is likely to be formed near the leading edge of the cutting line. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view showing an embodiment of the present invention; [Figure 2] FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. [Figure 11] An enlarged view of the tip portion in FIG. [Figure 12] An enlarged view of the tip in Figure 2. [Figure 13] An enlarged view of the tip in Figure 3. [Figure 14] An enlarged view of the tip in Figure 4. [Figure 15] An enlarged view of the front half of Figure 2. [Figure 16] 10 is a plan view showing the vicinity of a cutting line on a paper sheet when the cutting line is formed on the paper sheet using scissors according to the embodiment; FIG. [Figure 17] 10 is a right side view showing a state in which the blade pushes up a part of the paper sheet when a cutting line is formed on the paper sheet using the scissors of the embodiment. FIG. [Figure 18] 16A and 16B are plan views showing the vicinity of a cutting line on a paper sheet when the cutting line is formed on the paper sheet using scissors of the conventional example (plan views corresponding to FIG. 16A and 16B). [Figure 19] 17A and 17B are right side views showing a state in which the blades push up a part of the paper sheet when a cutting line is formed on the paper sheet using scissors of the conventional example (right side views corresponding to FIG. 17A and 17B). DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, one embodiment of the present invention will be described with reference to FIGS.

[0016] FIG. 18 is a plan view showing an example of a state in which a cut line c is formed on a paper sheet P using conventional scissors, and a scratch D is formed near the leading end ct of the cut line c.

[0017] 19 is a right side view showing a state in which the first blade piece 11x pushes up a part p1 of the paper sheet P when a cutting line c is formed on the paper sheet P using conventional scissors Sx. Here, the reference numeral for the conventional scissors Sx is the same as that used in this embodiment, but with an "x" added after it.

[0018] In this embodiment, the present invention is applied to scissors S suitable for use in an office or at home. The scissors S are suitable for use in cutting paper sheets P such as paper.

[0019] In particular, the scissors S of this embodiment are suitable for applications such as making paper crafts and paper cuttings, i.e., applications where there is a strong desire to maintain the appearance of the area near the cutting line c formed on the paper sheet P in a good condition.

[0020] The scissors S comprises a first scissors blade 1 which is one of the scissors blades, a second scissors blade 2 which is the other of the scissors blades, and a support shaft 3 which supports the first scissors blade 1 and the second scissors blade 2 so that they can rotate relative to each other, so that the first cutting edge e1, which is a cutting edge formed on the first blade piece 11, and the second cutting edge e2, which is a cutting edge formed on the second blade piece 21, slide against each other to cut paper sheets P such as paper.

[0021] The scissors S are movable around a support shaft 3 between an open position (not shown) in which the first cutting edge 11t, which is the tip (edge) of the first scissors body 1, and the second cutting edge 21t, which is the tip (edge) of the second scissors body 2, are spaced apart so that the paper sheet P to be cut can be placed between the first cutting edge 11t and the second cutting edge 21t, and a final cutting position (A) in which the first cutting edge 11t and the second cutting edge 21t are most overlapping in the blade movement direction r, forming a maximum overlap position (J).

[0022] The scissors S will be described in detail below.

[0023] <<First scissors 1>> The first scissors blade 1 includes a first cutting piece 11 made of metal, and a first handle 12 provided at a base end 11k of the first cutting piece 11 with which the fingers of the user engage.

[0024] <First blade piece 11> The first blade piece 11 is positioned below the paper sheet P when cutting the paper sheet P. The first blade piece 11 has a base material made of a stainless steel plate, which is a metal plate. The first blade piece 11 is made by press molding.

[0025] At least the first cutting edge 11t of the first cutting piece 11, which constitutes the tip of the first cutting piece 11, is ground until a predetermined thickness dimension w1 is obtained.

[0026] The first cutting edge 11 has a first cutting edge line e1 formed between a flat blade back surface 11b that is slidable along the second cutting edge 21 and a blade front surface 11s that faces away from the second cutting edge 21.

[0027] More specifically, the first cutting line e1 of the first cutting piece 11 is formed between the back surface 11b and the sharpening surface 11c formed at the end of the front surface 11s.

[0028] If the angle of the cutting surface 11c relative to the blade back surface 11b of the first cutting edge portion 11t is set to a value of 60° or less, when a cutting operation is performed to transition from the open position to the final cutting position (A), the displacement of the paper sheet P caused by the first cutting edge portion 11t (displacement in the thickness direction of the first cutting edge portion 11t relative to the portion near the tip end ct of the cutting line c) can be made gentle.

[0029] In this embodiment, the angle of the sharpening surface 11c relative to the blade back surface 11b is set to approximately 47.5°.

[0030] The first cutting edge e1 is set to a dimension of at least 20 mm. The total length of the first cutting edge e1 is preferably set within a range of 60 to 70 mm, with the upper limit being 90 mm. More specifically, the total length of the first cutting edge e1 in this embodiment is set to 65 mm.

[0031] A first cutting edge 11t, which is the tip of the first cutting piece 11, includes a most extreme point m of the first cutting line e1.

[0032] A rectangular hole Q, which includes an area through which the spindle 3 is inserted, is formed between the front part of the first cutting piece 11 where the first cutting line e1 is formed and the rear part of the first cutting piece 11 including the base end 11k embedded in the front end of the first shank 12. A bearing member g made of synthetic resin and having a circular shaft insertion hole gh is attached to the rectangular hole Q.

[0033] <First handle part 12> First handle 12 is made of synthetic resin. A base end 11k of first cutting piece 11 is attached to the front end of first handle 12. First handle 12 is provided with finger holes 12a for inserting the user's fingers.

[0034] In this embodiment, finger hole 12a of first handle 12 is formed smaller than finger hole 22a of second handle 22 so that the user's thumb can be inserted therein.

[0035] A first positioning portion 12b is provided in the longitudinal middle of the end face of first handle 12 facing second handle 22. The first positioning portion 12b protrudes further toward second handle 22 than the other end face. First positioning portion 12b can abut against second positioning portion 22b provided on second handle 22.

[0036] <<Second scissors 2>> The second scissors blade 2 includes a second cutting blade 21 made of metal, and a second handle 22 provided at a base end 21k of the second cutting blade 21 with which the fingers of the user engage.

[0037] <Second blade piece 21> The second blade piece 21 is positioned on the paper sheet P when cutting the paper sheet P. The second blade piece 21 has a base material made of a stainless steel plate, which is a metal plate. The second blade piece 21 is made by press molding.

[0038] At least the second cutting edge 21t of the second cutting piece 21, which constitutes the tip of the second cutting piece 21, is ground until a predetermined thickness dimension w2 is obtained.

[0039] The second cutting edge 21 has a second cutting edge line e2 formed between a flat blade back surface 21b that is slidable along the first cutting edge 11 and a blade front surface 21s that faces away from the first cutting edge 11.

[0040] More specifically, the second cutting line e2 of the second cutting piece 21 is formed between the blade back surface 21b and the sharpening surface 21c formed at the end of the blade front surface 21s.

[0041] If the angle of the cutting surface 21c relative to the blade back surface 21b of the second cutting edge portion 21t is set to a value of 60° or less, when a cutting operation is performed to transition from the open position to the final cutting position (A), the displacement of the paper sheet P caused by the second cutting edge portion 21t (displacement in the thickness direction of the second cutting edge portion 21t relative to the portion near the tip end ct of the cutting line c) can be made gentle.

[0042] In this embodiment, the angle of the sharpening surface 21c with respect to the blade back surface 21b is set to approximately 47.5°.

[0043] The second cutting edge e2 is set to a dimension of at least 20 mm. The total length of the second cutting edge e2 is preferably set within a range of 60 to 70 mm, with the upper limit being 90 mm. More specifically, the total length of the second cutting edge e2 in this embodiment is set to 65 mm.

[0044] The second cutting edge 21t, which is the tip of the second cutting piece 21, includes the most extreme point n of the second cutting line e2.

[0045] A shaft insertion hole 21h, through which the support shaft 3 is inserted, is provided between the front portion of the second cutting piece 21 where the second cutting line e2 is formed and the rear portion of the second cutting piece 21 including the base end portion 21k embedded in the front end portion of the second handle portion 22.

[0046] The tip 3t ​​of the support shaft 3, which passes through the shaft insertion hole gh of the bearing member g attached to the rectangular hole Q of the first cutting piece 11 and then through the shaft insertion hole 21h of the second cutting piece 21, is crimped and deformed on the outer surface side of the second cutting piece 21 to connect the first cutting piece 11 and the second cutting piece 21 so that they can rotate relative to each other.

[0047] <Second handle 22> Second handle 22 is made of synthetic resin. Base end 21k of second cutting piece 21 is attached to the front end of second handle 22. Second handle 22 is provided with finger holes 22a for inserting the user's fingers.

[0048] In this embodiment, finger hole portion 22a of second handle portion 22 is formed larger than finger hole portion 12a of first handle portion 12 so that fingers other than the thumb of the user (e.g., index finger, middle finger, ring finger, etc.) can be inserted therein.

[0049] A second positioning portion 22b is provided in the longitudinal middle of the end face of second handle 22 facing first handle 12. The second positioning portion 22b protrudes further toward first handle 12 than the other end face. Second positioning portion 22b can abut against first positioning portion 12b provided on first handle 12.

[0050] <Regarding the maximum overlap position (J) between the first cutting edge 11 and the second cutting edge 21> The maximum overlap position (J) where the first cutting edge 11 and the second cutting edge 21, which are connected by the support shaft 3 so as to be rotatable relative to each other, overlap most in the blade movement direction r is determined by the abutment of the first positioning portion 12b of the first handle 12 and the second positioning portion 22b of the second handle 22.

[0051] That is, when the scissors S assume the final cutting position (A), the first cutting blade 11 and the second cutting blade 21 assume a maximum overlap position (J) where they overlap most in the blade movement direction r.

[0052] <<Spindle 3>> The support shaft 3 connects the first scissors body 1 and the second scissors body 2 so that they can rotate relative to each other.

[0053] The support shaft 3 is disposed in front of the first handle portion 12 constituting the first scissors body 1 and the second handle portion 22 constituting the second scissors body 2.

[0054] <Concerning the thicknesses w1 and w2 of the first cutting edge portion 11t and the second cutting edge portion 21t> In the scissors S of this embodiment, as shown particularly in Figure 11, at the most overlapping position (J) where the first cutting edge portion 11t and the second cutting edge portion 21t overlap most in the blade movement direction r, the thickness dimension w1 of the most distal end of the first cutting edge portion 11t, which is located at a position corresponding to the first imaginary straight line k1 perpendicular to the blade movement direction r from the most distal point n of the second cutting line e2, is set to 0.2 to 0.7 mm.

[0055] In addition, in the scissors S of this embodiment, at the most overlapping position (J), the thickness dimension w2 of the most distal end of the second cutting edge portion 21t, which is located at a point corresponding to the second imaginary line k2 perpendicular to the blade movement direction r from the most distal point m of the first cutting line e1, is set to 0.2 to 0.7 mm.

[0056] Here, if the thickness dimensions w1 and w2 of the relevant parts of the first cutting edge portion 11t and the second cutting edge portion 21t are set to values ​​smaller than 0.2 mm, the intended purpose of making it difficult for unintended tears, distortions, or other damage D to form near the tip ct of the cutting line c in the paper sheet P is easily achieved, but on the other hand, the problem of chipping of the blades occurs.

[0057] In other words, if the thickness dimensions w1 and w2 of the corresponding portions of the first cutting edge portion 11t and the second cutting edge portion 21t are set to values ​​of 0.2 mm or more, the risk of chipping can be suitably reduced while achieving the initial objective.

[0058] Furthermore, if the thickness dimensions w1 and w2 of the relevant parts of the first cutting edge 11t and the second cutting edge 21t are set to values ​​greater than 0.7 mm, the first and second cutting edges 11t and 21t will act to further expand the tip ct of the cutting line c in the lateral direction, making it more likely that unintended tears, distortions, or other damage D will be formed in the paper sheet P near the tip ct of the cutting line c.

[0059] In other words, if the thickness dimensions w1 and w2 of the corresponding parts of the first cutting edge portion 11t and the second cutting edge portion 21t are set to a value of 0.7 mm or less, it becomes difficult for unintended tears, distortions, or other damage D to be formed near the tip ct of the cutting line c in the paper sheet P.

[0060] In this embodiment, the thicknesses w1 and w2 of the corresponding portions of the first cutting edge 11t and the second cutting edge 21t are set to 0.5 mm or less.

[0061] <Regarding the overlap dimension wp of the first cutting edge portion 11t and the second cutting edge portion 21t in the blade movement direction r> In the scissors S of this embodiment, at the most overlapping position (J), the overlap dimension wp in the blade movement direction r at the most distal ends of the first cutting edge portion 11t and the second cutting edge portion 21t is set to a value greater than 0 and less than or equal to 1.0 mm.

[0062] Here, if the overlap dimension wp in the blade operation direction r at the very tip of the first cutting edge 11t and the second cutting edge 21t is set to a value smaller than 0, not only will the very tip of the first cutting edge 11t and the very tip of the second cutting edge 21t not be able to cut the paper sheet P even in the final cutting posture (A), but the first cutting line e1 and the second cutting line e2 included in the first cutting edge 11t and the second cutting edge 21t will always be exposed, resulting in a safety hazard.

[0063] Furthermore, if the overlap dimension wp in the blade operation direction r at the very tip of the first cutting edge 11t and the second cutting edge 21t is set to a value greater than 1.0 mm, when the first cutting edge 11t and the second cutting edge 21t form a cutting line c on the paper sheet P, the first cutting edge 11t and the second cutting edge 21t will push the paper sheet P in opposite directions, which will tend to concentrate stress near the tip ct of the cutting line c on the paper sheet P, making it more likely that damage D such as tears or distortions will be formed.

[0064] In this embodiment, at the most overlapping position (J), the overlap dimension wp in the blade movement direction r at the most distal ends of the first cutting edge 11t and the second cutting edge 21t is set to 0.5 mm.

[0065] <Structure provided on the first blade piece 11 to prevent the paper sheet P from being pushed up during cutting> In the scissors S of this embodiment, the first blade piece 11 of the first scissors body 1 is provided with a structure for suppressing upward pushing up of a portion p1 of the paper sheet P when the paper sheet P is cut. The portion p1 of the paper sheet P is a portion that is pushed up by the first blade piece 11, and refers to a portion adjacent to the side of the first blade piece 11.

[0066] That is, a downwardly recessed recess 11w including a curved or bent first cutting line e1 is formed in front of the spindle 3 in the first cutting piece 11. The first cutting line e1 (hereinafter referred to as the "first cutting line front portion e1f") located in front of the recess 11w in the first cutting piece 11 extends in a substantially straight line between the recess 11w and the most distal point m of the first cutting line e1, and is inclined at an angle Θ greater than 0° and equal to or less than 5° with respect to an imaginary line wi connecting the axial center point js of the spindle 3 and the most distal point m of the first cutting line e1.

[0067] If the inclination angle Θ is smaller than 0°, it becomes difficult to form a cutting line c on the paper sheet P. If the inclination angle Θ is set to an angle larger than 5°, the first blade piece 11x or the second blade piece 21x will push a portion p1 of the paper sheet P upward or downward to an excessive extent, as shown in Fig. 19, and loads will tend to concentrate on the leading end ct of the cutting line c on the paper sheet P, making it easier for damage D such as tears or distortions to be formed.

[0068] Here, when the inclination angle Θ of the front portion e1f of the first cutting line relative to the imaginary straight line wi is set within the range of 2° to 3°, it is possible to achieve a balanced condition in which the cutting line c can be formed smoothly on the paper sheet P and the condition in which damage D such as tears or distortions is unlikely to be formed near the leading end ct of the cutting line c.

[0069] In this embodiment, the inclination angle Θ of the first cutting line front portion e1f with respect to the imaginary straight line wi is set to 3°.

[0070] In this embodiment, the first cutting edge 11 is set so that the position of the first cutting edge e1, which is located in front of the recess 11w, is closer to the imaginary line wi than the inner edge of the first cutting edge 11, which is located behind the recess 11w.

[0071] As described above, the scissors S of this embodiment comprises a first scissors body 1, which is one of the scissors bodies, including a first blade piece 11, which is a blade piece having a first blade line e1, which is a cutting edge; a second scissors body 2, which is the other of the scissors bodies, including a second blade piece 21, which is a blade piece having a second blade line e2, which is a cutting edge; and a support shaft 3 that supports the first and second scissors bodies 1 and 2 so that they can rotate relative to each other so that both blade lines, i.e., the first and second blade lines e1 and e2, slide to cut paper sheets.

[0072] The scissors S have a recess 11w formed in the first cutting piece 11 forward of the support shaft 3, and a first cutting edge e1 located in front of the recess 11w extends in a substantially straight line between the recess 111 and the most distal point m of the first cutting edge 11t of the first cutting piece 11, and is inclined at an angle greater than 0° and less than 5° with respect to an imaginary line wi connecting the axial center point js of the support shaft 3 and the most distal point m of the first cutting edge 11t.

[0073] Therefore, in this embodiment, it is possible to minimize the problem that, at least when a paper sheet P is cut, damage D such as unintended tears or distortions is likely to be formed near the leading end ct of the cutting line c.

[0074] That is, in this embodiment, the first cutting line e1 of the first blade piece 11 is slightly inclined with respect to the imaginary line wi, so that a portion p1 of the paper sheet P is not excessively pushed upward by the first blade piece 11 rising during cutting, and it is possible to suitably prevent an excessive load from acting on the leading end ct of the cutting line c of the paper sheet P.

[0075] As a result, as shown in Figure 16, damage D such as tears or distortions is less likely to occur on the paper sheet P near the tip ct of the cutting line c formed by the cooperation of the first blade piece 11 and the second blade piece 21, and damage to the function or appearance of the paper sheet P due to damage D such as tears or distortions is minimized.

[0076] The position of the first cutting line e1 located in front of the recess 11w is set to be closer to the imaginary line wi than the inner edge of the first cutting piece 11 located behind the recess 11w.

[0077] Therefore, by forming a recess 11w in the first cutting piece 11, the position of the first cutting line e1, i.e., the first cutting line front portion e1f, which is located in front of the recess 11w, can be suitably brought close to the imaginary straight line wi.

[0078] The first and second scissors blades 1 and 2, which are one and the other scissors blades, have first and second handle portions 12 and 22, which are handle portions with which the user's fingers engage, provided at the base ends 11k and 21k of the first and second cutting pieces 11 and 21, and the support shaft 3 is arranged in front of the first and second handle portions 12 and 22.

[0079] Therefore, the user can place his / her fingers on the first and second handle portions 12 and 22 and operate the first and second cutting pieces 11 and 21 comfortably.

[0080] The present invention is not limited to the above-described embodiment.

[0081] The recess may be formed on both or either one of the cutting blades, and is not limited to being formed only on the first cutting blade as in the above-described embodiment.

[0082] The cutting edge line may be inclined at an angle of more than 0° and not more than 5° with respect to the imaginary straight line on both or only one of the first and second cutting pieces.

[0083] In the above-described embodiment, the first scissors blade is the side operated by the user's thumb (the so-called moving blade side) and the second scissors blade is the side operated by the user's fingers other than the thumb (the so-called stationary blade side), but these may be reversed.

[0084] In other words, the scissors may have the second blade as the side operated by the user's thumb (the so-called moving blade side) and the first blade as the side operated by the user's fingers other than the thumb (the so-called stationary blade side).

[0085] The paper sheets to be cut by scissors are not limited to paper sheets, but may be any sheet-like material.

[0086] It goes without saying that the first and second handles may not be formed separately from the first and second cutting blades.

[0087] Furthermore, the specific configuration of each part is not limited to the above embodiment, and various modifications are possible within the scope of the present invention. [Explanation of symbols]

[0088] 1...first scissors 11...First blade piece e1…first blade line 12...First handle 2…Second scissors 21…Second blade piece e2…Second blade line 22...Second handle 3…Spindle P…paper leaves c…cutting line D...Damage such as tears or distortion wp...imaginary line e1f…First blade line front part Θ…Inclination angle

Claims

1. A pair of scissors comprising one blade including a blade having a cutting edge formed with a cutting line, another blade including a blade having a cutting edge formed with a cutting line, and a support shaft that supports the one and other blades so that they can rotate relative to each other to slide the cutting edges of both blades to cut paper sheets, a recess is formed in front of the support shaft in either one or both of the blade pieces, The scissors have a cutting edge line located in front of the recess that extends in a substantially straight line between the recess and the tip of the cutting edge, and that is inclined at an angle greater than 0° and less than 5° with respect to an imaginary line connecting the axial center point of the support shaft and the tip of the cutting edge.

2. 2. The scissors according to claim 1, wherein the cutting edge line located in front of the recess is set to be closer to the imaginary line than the inner edge of the cutting piece located behind the recess.

3. The one and the other scissors blades have handles at the base ends of the blades with which the user's fingers engage, 2. The scissors according to claim 1, wherein the support shaft is disposed in front of the handle portion.

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