JP2014025202A - Grooving cutter for sheet being operable without using ruler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a machine tool capable of easily cutting, without using a ruler, sheets successively laid over a surface of a base material for a floor via adhesives, over both the sheets in accordance with a seam of a straight line or a curved line.SOLUTION: A grooving cutter for a sheet comprises: a front part 3; an intermediate part 4; and a rear part 5. A distal end portion of the front part is formed circular or elliptical. The front part includes a guide roller 6, in the front end portion thereof, with a thin rotary plate which moves in between seams of sheets and guides the cutter in accordance with the seams when the cutter is pushed forward. At the back of the guide roller, at least one blade that grooves a seam portion of the sheets in a recessed shape is provided in a freely removable manner. The rear part includes a stabilizing member which is not rotated, for stabilizing a moving direction of a machine tool by moving into the groove provided by the blade.

Description

  The present invention relates to a sheet grooving cutter capable of forming a concave groove on a sheet, which is necessary when a seam of floor sheets is firmly connected using a welding rod, and in particular, straddles the seam of the floor sheet. The present invention relates to a sheet grooving cutter capable of forming a concave groove quickly and accurately without using a ruler.

  In general, when a sheet is stretched on a base material of a floor, a method of pouring a welding rod melted by heat into the joint portion is taken in order to firmly join the joint portion between individual sheets. In this case, since the sheets are usually laid from the beginning so that the joint surfaces of the adjacent sheets are in close contact with each other, it is difficult to push the welding rod melted by heat directly into the gap between the seams. Even if you try to push it in directly, the welding rod melted on the seam surface will only harden in a raised state (see Fig. 1). Therefore, it is practically impossible to firmly bond the sheets by this method because the raised surface is simply removed by simply scraping the raised portion to make the floor surface flat.

  Therefore, in general, a U-shaped or V-shaped groove is cut in the joint portion with a hand cutter (see Fig. 2), a welding rod melted by heat is poured into the groove, and the raised portion is cut off from the surface. The surface is finished flat (see FIG. 3). According to this method, since the sheets are thin or stiff, it is possible to join the sheets firmly to some extent except when it is difficult to cut a groove having a desired depth.

  In any case, it is necessary to cut a concave groove extending evenly across the seam without swaying left and right from the seam by the above-described grooving operation. Therefore, the groove is usually cut while applying the blade of the cutter to a ruler arranged in parallel with the seam so that the seam is positioned at the center of the blade of the U-shaped or V-shaped cutter. This method does not take much time when the seam is short, but it has the disadvantage that the floor area becomes large, and when the distance of the seam is long, it takes a lot of time and labor, and the work cost becomes enormous. .

  Therefore, a grooving tool having a guide function has been proposed so that the groove can be easily cut on the joint of the sheet (for example, Patent Document 1). In the case of this tool, since it has a two-point support configuration of the blade edge and the guide roller abutting portion with respect to the sheet surface, a relatively stable operation can be performed, but between the support point and the gripping portion. Since the distance is long, not only is the stability limited, but the tool itself is easily damaged.

  In addition, a floor grooving device having a roller having a seam guide function at the front end of the apparatus main body has also been proposed (Patent Document 2). However, just providing a blade immediately after the seam guide roller requires skill to operate it along the seam, and enters the groove provided by the blade at the rear of the apparatus body. When a roller having a width wider than that of the guide roller is provided to improve the seam followability, the slippage of the tool becomes too light and the guide roller is liable to be removed. In addition, since it is difficult to perform an operation corresponding to a curved seam such as a square front surface of the tool, when forming a curved groove, a rear roller and a second blade are provided at the rear. In some cases, the blade must also be removed, which has the disadvantage of being complicated.

Japanese Utility Model Publication No. 6-57606 US Patent 6,640,446

  As a result of intensive studies to improve the conventional drawbacks, the present inventors have inserted a roller having a thin rotating plate that is inserted into a sheet seam at the tip of the tool and guides the tool along the seam. And a blade for grooving the seam portion of the sheet in a concave shape, and a fixing member having a cross-sectional shape at the tip adapted to the groove formed by the blade is provided near the rear end of the tool. In this case, not only the followability with respect to the seam of the sheet is good, but also the followability with respect to the unevenness of the floor can be improved while ensuring light operability, and the depth of the groove formed in the seam of the sheet is improved. While finding that it can be made more uniform than before, forming the second groove in the first groove makes it difficult to remove and replenish the welding rod replenished in the groove, thereby joining the sheets together Than before And by tilting the tool bottom surface near the tip having the roller upward by an appropriate angle toward the tip, the tool can be moved forward according to the tilt even when the seam is curved. It has been found that by tilting it can be easily operated along the seam, the present invention has been achieved.

Therefore, the first object of the present invention is that it can be easily operated without using a ruler or the like, and is excellent in uniformity of depth quickly and accurately in the seam of the sheet according to the unevenness of the floor. An object of the present invention is to provide a sheet grooving cutter capable of cutting a groove.
A second object of the present invention is to provide a sheet grooving cutter that can easily cut a groove along the seam even if the seam is curved.
A third object of the present invention is to provide a sheet grooving cutter capable of continuously cutting a second groove in a groove that was initially cut in a single operation.
It is a fourth object of the present invention to provide a method for cutting a deeper second groove into the first cut groove in a single operation.

  The above-mentioned objects of the present invention are a tool for cutting a sheet so as to straddle both sheets according to the seam of the sheets generated when the sheets are sequentially laid on the surface of the base material of the floor via an adhesive. A front part, a middle part, and a rear part, and the frontmost part of the front part is circular or elliptical, the front part enters the front end of the joint, and the tool is forward A guide roller having a thin rotating plate that guides the tool according to the seam when pushed to the rear, and at least one blade for grooving the seam portion of the sheet in a concave shape after the guide roller is detachable And a non-rotating stabilizing member that enters the groove provided by the blade and stabilizes the moving direction of the tool at the rear portion, and can be operated without using a ruler. And a groove that is shallower than the thickness of the sheet by the first blade, and then further into the groove provided by the first blade by the second blade. This has been achieved by a method of grooving the sheet seam, characterized by forming deep flutes.

  The sheet grooving cutter of the present invention can be attached to and detached from the rear end portion of the rear portion by using a tool that reverses the tool and moving the rear portion as the front portion. Alternatively, the front bottom portion having the guide roller may be provided so as to be slidable back and forth.

  Further, a pair of rollers and / or wheels running on the sheet surface may be provided on the left and right sides of the tool in the vicinity of the stabilizing member of the rear portion, and a separate grip portion is provided mainly on the upper portion of the intermediate portion. You may have. Furthermore, it is preferable that the blade is disposed immediately after the guide roller, and a second blade having a width narrower than the width of the blade is formed behind the first blade by a groove formed by the first blade. It can also be detachably arranged so that a deeper groove can be cut into the inside.

  The stabilizing member provided at the rear part is preferably a fixing member having a tip cross-sectional shape that substantially corresponds to a cross-sectional shape of a groove formed by a blade, and the guide roller is at the forefront of the tool bottom surface. Also good. Moreover, it is preferable that the front-end | tip bottom face of the front bottom part which has the said guide roller is processed so that it may incline upwards.

  Further, in the sheet grooving cutter of the present invention, the front end portion including the guide roller, which is in front of the first blade provided at the front portion, is detachable from the tool or can be rotated upward. When the part is removed or rotated upward, the first blade of the front part may be configured to protrude ahead of the tool.

  The grooving cutter of the present invention can easily and accurately cut a concave groove at the seam of a sheet without using a ruler or the like. When a ruler is used, it is complicated and neatly cuts. It is difficult to groov the seam of a sheet constructed in a large area and to the curved seam of the design, and it can be easily and accurately performed without detaching from the seam of the sheet. It is. Furthermore, when further grooving in the groove provided first, the welding rod that is heated and pushed in is less likely to come off from the sheet than when a simple groove is provided. Not only the work efficiency of the grooving welding work is remarkably improved, but also the adhesion between the sheets can be made stronger.

FIG. 1 is a cross-sectional view showing a state where a seam portion is covered with a molten welding rod without cutting a groove on a seam of a sheet. FIG. 2 is a perspective view of a state in which a U-shaped groove is cut on the seam of the sheet as viewed obliquely from above. Fig. 3 shows a state in which a welding rod melted by heat is poured into a U-shaped groove on the seam of the sheet and hardened, and the surface of the welding rod that has risen from the surface is scraped off to make the surface flat. FIG. FIG. 4 is a left side explanatory view showing an example of the grooving cutter of the present invention. FIG. 5 is an explanatory bottom view of the bottom of the grooving cutter of FIG. FIG. 6 is a left side surface explanatory view in which the blades 7 and 7 ′ are omitted in the grooving cutter of the present invention when the front plate is movable back and forth. FIG. 7 is an explanatory bottom view of the grooving cutter body of FIG. FIG. 8 is an explanatory view showing an example of the front plate. FIG. 9 is an explanatory view showing an example of the rear plate. FIG. 10 is a front explanatory view of the grooving cutter of FIG. 6 with the plate omitted. FIG. 11 is a rear view of the grooving cutter of FIG. 6 with the plate omitted. FIG. 12 is a diagram for explaining the grooving cutter of the present invention in the case of having two blades facing forward.

EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited by these Examples. In the present specification, the sheet grooving cutter of the present invention may be hereinafter simply referred to as “tool”.
FIG. 4 is an example of a side view of the grooving cutter of the present invention when the main body is manufactured integrally except for the bottom part and the movable part. 2 is a gripping part, 3 is a front part having a rounded tip, 4 is an intermediate part, 5 is a rear part, 6 is a guide roller having a thin disc inserted into a sheet seam, rotating together with a shaft 12, 7 And 7 'are U-shaped and V-shaped concave groove cutting blades, 8 and 8' are groove-shaped or tubular spaces provided for mounting the groove cutting blades, and 9 and 9 'are groove cutting blades. The attachment / detachment / adjustment screw 10 is a bottom that covers the entire area of the front, middle, and rear, and the middle part is used to lightly move the tool during use as in this embodiment, and the floor base. It is preferable that it is designed not to come into contact with the seat in order to have good trackability against unevenness. Arbitrariness.

Further, from the viewpoint of easily dealing with a case where the seam of the sheet is a curve, it is preferable that the front end of the bottom portion is processed so as to be inclined upward (may be spherical or the like). (Reference numeral 19). Reference numeral 11 functions as a stabilizing member with respect to the traveling direction of the tool when the tool is used when the seam of the sheet is a straight line or a substantially straight line. It is a fixing member having a shape, an elliptical shape, or the like. For example, these fixing members are provided with a male screw on the fixing member, and a screw hole is formed on the bottom surface of the main body to be screwed with the male screw. It may be appropriately provided by a known fixing means such as using an agent or fixing to the rear bottom surface of the main body by welding.
Reference numeral 13 denotes a pair of rollers provided for improving the lateral stability of the tool when the tool is used, and reference numeral 12 ′ denotes an axis of the roller.

FIG. 5 is a bottom view of the bottom 10 in which the grooving blades 7 and 7 ′ are omitted from the tool shown in FIG. 4. Reference numerals 14 and 14 'in the figure are openings in which groove-like or tubular spaces 8 and 8' for mounting the blades appear on the bottom surface, and the groove cutting blades 7 and 7 'pass through these openings. . Reference numeral 15 denotes a screw hole for fixing the bottom 10 to the main body with a screw. The number and position of the places where the bottom 10 is fixed can be designed as appropriate. It is necessary to use a countersunk screw as the screw so that the screw thread does not protrude from the bottom.
Of course, the tool of this invention can also manufacture all the non-movable parts including the bottom part 10 integrally. The material can be appropriately selected from known materials such as metals, plastics, and ceramics. In the present invention, it is particularly preferable to use aluminum.

  FIG. 6 shows an example in which the bottom of the main body is directly designed so that the bottom of the intermediate portion does not come into contact with the sheet. In particular, the front plate 20 having the guide roller 6 is arranged at the front of the bottom of the main body. It is an example in the case of being provided in a movable and detachable manner.

  FIG. 7 shows an example of a bottom part in the case where a plate made of a material having a high hardness such as SUS is detachably attached to the bottom part of the front part and the bottom part of the rear part so as to be able to withstand friction with the seat in use. FIG. In this embodiment, flanges 16 are provided on the left and right sides of the front part and the rear part so that the plate can be easily attached and detached with a single bolt. Reference numeral 17 denotes a screw hole for fixing the front plate 20 with screws, and 18 denotes a screw hole for fixing the rear plate with screws. When the high hardness plate is not attached to the bottom of the rear part, it is preferable to reinforce the flange part itself provided at the bottom part of the rear part or at least the surface thereof with a scratch-resistant material.

  FIG. 8 is a view showing an example of a front plate 20 that is movably provided in the front and rear at the bottom of the front. Reference numeral 21 in the figure is an opening for penetrating the grooving blade 7 and corresponds to the opening 14 in FIG. The shape of each opening can be designed as appropriate so that chips can be easily discharged. Reference numeral 22 denotes a slit for moving the front plate 20 back and forth and fixing it at a predetermined position with screws. In the case of this embodiment, the guide roller disc is provided in the opening 21 so that the guide roller disc is located before the frontmost portion of the front plate. A guide roller can also be provided.

FIG. 9 is a diagram illustrating an example of the rear plate 30. Reference numeral 31 in the drawing is an opening for screwing a bolt into the screw hole 18 provided in the main body in order to fix the rear plate 30. The rear plate 30 may be provided with the stabilizing member 11, but the stabilizing member 11 may be provided directly on the main body without being provided on the rear plate 30.
10 and 11 are a front view and a rear view of the sheet grooving cutter of FIG. 6 in a state in which the front plate and the rear plate are not attached, and is a view for explaining the role of the flange. When the plate fixing means is provided at two or more locations, the flange portion need not be provided.

  When the tool of the present invention is operated, the grip portion is gripped. However, when the grip portion shown in the above embodiment is not particularly provided, the intermediate portion is practically the grip portion. Such a tool is also one embodiment of the present invention. Of course, it is free to design a shape that is easy to hold from the middle part to the rear part. In addition, the grip portion 2 in the present embodiment is an integral type with the main body, which is formed in a shape that is easy to grip by hollowing out the main body, but the grip portion 2 is manufactured as a grip independent of the main body, and using a fixing means It is also possible to adhere to the main body as appropriate. In any case, when the contact area between the bottom of the tool of the present invention and the sheet becomes large, not only does the movement of the tool during the use of the tool become heavy, but also it becomes difficult to pick up unevenness of the floor base, and the uniform depth Since it becomes difficult to form a groove, it is preferable to design the contact area as small as possible.

The front part having the guide roller 6 has an opening 14 behind the guide roller 6, and the groove cutting blade 7 protrudes from the bottom surface of the front part through the opening. In this case, if the distance between the grooving blade 7 and the guide roller 6 is too small, chips will not easily come out from between the grooving blade 7 and the guide roller 6, so at least the depth of the groove to be provided. It is necessary to leave an interval. However, this distance remains as a distance that cannot be cut when an obstacle such as a wall is reached. Therefore, in the present invention, in order to shorten the remaining distance, the front bottom portion having the guide roller is designed to be movable back and forth, using a plate, and the grooving blade 7 and the guide roller 6 are designed. In order to be able to adjust the distance between them, or to eliminate the remaining distance, the part of the guide roller 6 is made entirely removable, or the part of the guide roller 6 is upward, particularly 90 ° or more. It is preferable to design so that it can rotate upward.
In addition, since the bottom part of the front part corresponding to the front plate part 20 having the guide roller 6 is a part in contact with the sheet, in order to make it easy to pick up unevenness of the ground of the sheet, the area as small as possible (short plate or It is preferable to use a short bottom.

  Moreover, in this invention, in order to eliminate the problem of said cutting remaining part, the blade equivalent to the said blade can also be provided in a rear-end part. If the protruding distance of the blade from the tool bottom is adjusted to the depth of the groove, the blade can also function as a stabilizing member in a normal use state. The blade at the rear end can be always protruded, but it is preferably provided so as to be able to be inserted and removed freely in order to increase the safety of the tool and prevent blade spillage. For this purpose, for example, as in the case where the front blade 7 is detachably disposed using a screw 9 or the like, those skilled in the art can easily perform a design using a known technique such as a screw 9 '. be able to.

  In the present invention, the rear end blade 7 'is equivalent to the blade used at the front portion, and / or corresponds to the cross section of the cut groove, such as a rod or hemisphere. By providing the fixing member 11, stability in the moving direction when using the tool of the present invention can be ensured, but this alone may result in insufficient lateral stability of the tool. Therefore, in the present invention, it is preferable to arrange a wheel or a pair of rollers 13 wider than the wheel on the left and right of the tool in the vicinity of the stabilizing member 11. The wheel or roller 13 may rotate freely around the fixed rotation shaft 12 or may rotate integrally with the shaft 12. In addition, the direction of an axis | shaft is a direction orthogonal to the longitudinal direction of a tool, and this is parallel to the axis | shaft of a guide roller.

  By providing the wheel or roller 13 as described above, the stability in the direction of movement and the direction orthogonal thereto when using the tool of the present invention is sufficiently high. In this case, use of the tool causes unnecessary friction. From the viewpoint of facilitating picking up unevenness at the time of grooving, it is preferable that the rear bottom surface is designed not to come into contact with the seat, like the middle bottom surface. In order to make it easy to pick up unevenness of the sheet, it is preferable to design the radius of the wheel or roller 13 as small as possible.

  By the way, it is not uncommon for the sheet seam 40 to be a curved line instead of a straight line. In the present invention, it is preferable that the guide roller 6 is disposed at the forefront of the tool from the viewpoint of corresponding to the groove cutting across such a curved seam. However, in this case, there is a disadvantage that the risk of the guide roller 6 breaking due to the tool colliding with an obstacle such as a wall is increased. In order to eliminate such drawbacks, the front end of the tool front is present in front of the guide roller so that the guide roller 6 does not directly contact the obstacle, that is, an opening provided near the front end of the front roller. It is preferable to arrange the guide roller inside.

  In any case, when it corresponds to the curved seam, the tool of the present invention is tilted forward so that the rear fixing member 11 and the blade 7 'provided at the rear end are floated, and along the curved seam. It is preferable to be able to operate freely. Therefore, in the present invention, it is preferable to process the front end of the bottom portion of the front portion so as to be inclined upward (that is, the tool can be inclined forward) (see FIG. 4). When the inclined surface 19 on the bottom surface of the front end portion thus provided is brought into close contact with the sheet, only this close contact surface comes into close contact with the sheet. Can follow the seam. Of course, in order to adapt to this case, if a grooving blade with a shape different from that of the blade that cuts the straight seam is used, or if the same blade as that of the straight seam is used, the angle suitable for the case of the curved seam The blade is preferably designed so that the blade can be fixed and adjusted to the main body. In addition, it is preferable that the guide roller is designed to be large so that the guide roller does not come off the seam of the sheet even if the tool is tilted forward.

  Since the guide roller 6 (see FIG. 4) arranged at the front portion is inserted into the joint of the sheet without the groove, the insertion depth of 1 mm or more is necessary, but it does not reach the bottom of the sheet. Also good. The insertion of the guide roller 6 makes it possible to move the tool according to the seam. Therefore, when the sheet seam 40 is a curved line, the tool is tilted forward, so that only the front guide roller 6 is inserted into the sheet seam, and the stabilizing member and blade disposed at the rear part are Then, it floats from the sheet. In addition, the thickness of the sheet | seat used as the object which uses the tool of this invention is 3 mm-7 mm normally.

  In the tool of the present invention, a groove-like or cylindrical space 8 is provided in the main body from the opening 14 upward and rearward. In this space 8, for example, a U-shaped grooving blade 7 is inserted, and the direction of the blade and the amount of protrusion from the bottom surface are appropriately adjusted, and then fixed by a known method, for example, a screw 9.

  When the guide roller 6 is inserted into the seam 40 of the sheet and pushed forward by holding the grip portion of the tool of the present invention, the U-shaped grooving blade 7 disposed behind the guide roller 6 causes the sheet to be The seam 40 is cut into a concave shape. The cut pieces of the cut sheet rise along the groove of the U-shaped groove cutting blade 7, pass through the opening 14, are guided above the tool body, and then discharged. In the present invention, the opening 14 is appropriately designed in a shape in which chips are not easily clogged.

  In the present invention, a second blade (see FIG. 12) having a width narrower than the width of the first blade is placed behind the blade (first blade) disposed at the front portion by the first blade. You may arrange | position so that a deeper groove | channel may be cut in the formed groove | channel. In this case, the groove formed by the first blade is made relatively shallow, and the distance by which the second blade protrudes from the bottom surface of the tool body is adjusted so that the overall depth of the groove is less than the thickness of the sheet. There is a need to.

  In this embodiment, after the groove is cut by the first blade, a groove narrower than the width of the groove is formed by the second blade at the bottom of the groove. Thereby, the groove depth on the joint 40 of the sheet is increased, and a groove structure in which the intermediate portion of the groove cross section is constricted can be realized. As a result, since the welding rod 50 that has been welded and pushed in is difficult to be removed, adhesion of the seam between the sheets becomes stronger than in the case of a simple groove shape. In addition, it is preferable to provide the opening part which guides a chip also about such a 2nd blade.

  If the groove cutter of the present invention is used, it is possible to easily and accurately cut a concave groove in the seam of a sheet without using a ruler or the like, which was difficult when using a ruler, It is possible to cut the groove of uniform depth by improving the followability to small unevenness, and to cut the groove of the curved seam provided in the design easily and accurately. The operation can be further grooved in the first groove, so not only can the work efficiency of conventional groove cutting welding work be improved significantly, but also the welding rod that is heated and pushed into the groove Can be made difficult to come off from the sheet, and the adhesion between the sheets can thereby be strengthened. Therefore, the present invention is extremely useful industrially.

DESCRIPTION OF SYMBOLS 1 Body part 2 Gripping part 3 Front part 4 Intermediate part 5 Rear part 6 Guide roller 7, 7 ', 7''Concave groove cutting edge 8, 8', 8 '' Groove shape provided for mounting a groove cutting blade Or tubular space 9,9 ', 9''Groove blade attachment / detachment / adjustment screw
10 Bottom covering the entire front, middle and rear
11 Stabilizer
12, 12 'rotation axis
13 Roller
14, 14 'opening through the blade
15 Screw holes for fixing the bottom to the body with screws
16 Flange
17 Screw holes for securing the front plate with screws
18 Screw holes for securing the rear plate with screws
19 Inclined surface
20 Front plate
21 Openings in the front plate
22 Slit on the front plate
30 Rear plate
31 Opening for fixing the rear plate 30 to the screw hole 18 of the main body with bolts
40 sheet seam
50 Welding rod

Claims (11)

  A tool that cuts a sheet so as to straddle both sheets according to the seam of the sheet generated when the sheets are sequentially laid on the surface of the base material of the floor, the tool comprising a front part, an intermediate part, and a rear part The front end of the front part is circular or elliptical, and enters the front end of the front part between the seams, and the tool is pushed according to the seam when the tool is pushed forward. A guide roller having a thin rotating plate for guiding the sheet, and after the guide roller, at least one blade for grooving the seam portion of the sheet in a concave shape is detachable, and the blade is provided at the rear portion. A sheet grooving cutter that can be operated without using a ruler, comprising a non-rotating stabilizing member that enters a groove provided by the step and stabilizes the movement direction of the tool.   At the rear end portion of the rear portion, a blade used for grooving the seam portion in a concave shape, which is used when the tool is moved upside down, is detachable or detachable so as to protrude forward of the tool when used. 2. A sheet grooving cutter according to claim 1, which can be operated without using a ruler.   The grooving cutter for sheets according to claim 1 or 2, wherein a front portion provided with the guide roller is slidably provided back and forth, and can be operated without using a ruler.   The ruler according to any one of claims 1 to 3, wherein the ruler has a pair of rollers and / or wheels that run on the sheet surface on the left and right sides of the tool in the vicinity of the stabilizing member of the rear part. Sheet grooving cutter that can be operated easily.   The sheet grooving cutter which can be operated without using a ruler, according to any one of claims 1 to 4, which has a separate grip portion mainly at an upper portion of the intermediate portion.   A blade provided in the front portion is disposed behind the guide roller, and a second blade having a width smaller than the width of the first blade disposed in the front portion is formed by the first blade behind the guide roller. The groove for a sheet which can be operated without using a ruler according to any one of claims 1 to 5, which is detachably arranged so that a deeper groove can be cut into the groove. Cutting cutter.   The grooving cutter for a sheet that can be operated without using a ruler according to any one of claims 1 to 6, wherein the leading edge of the front part is present so that the guide roller does not come into contact with an obstacle. .   A sheet grooving cutter which can be operated without using a ruler, according to any one of claims 1 to 6, wherein a guide roller is disposed at the frontmost part of the front part.   The ruler according to any one of claims 1 to 7, wherein the ruler is processed so that a bottom surface of the frontmost front end portion having the guide roller is inclined upward and / or designed to be detachable. Sheet grooving cutter that can be operated without using it.   When the front end including the guide roller before the first blade provided at the front is detachable or pivotable upward from the tool, or when the front end is removed or The first blade provided at the front portion protrudes ahead of the tool when rotated upward, and can be operated without using a ruler. Sheet groove cutter. A method for cutting a groove at a seam of a sheet using a sheet grooving cutter which can be operated without using a ruler according to any one of claims 6 to 10, wherein the groove is formed by a first blade. A groove at the seam of the sheet, wherein the depth to the bottom surface of the groove is set to be shallower than the sheet thickness, and a deeper groove is formed in the groove provided by the first blade by the second blade. To cut off.

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