JP2010099888A - Claw apparatus of sheet-fed rotary press - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control the misalignment of a biting position of a sheet-like object when a large tension force is applied to the sheet-like object in the reverse direction to the delivery direction in a claw apparatus of a sheet-fed rotary press. <P>SOLUTION: A plurality of first protrusions 17 which bite the surface of a paper when the paper is pulled in the reverse direction to the delivery direction are formed in an extending manner in the center of the direction (the direction indicated by a double arrow C-D) perpendicular to the paper delivery direction of the biting surface 15 of the claw 13. Second protrusions 18 which do not bite the surface of the paper when the paper is released for the next paper to be bit are formed at both ends of the direction indicated by the double arrow C-D. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a nail device in a sheet-fed rotary printing press in which a sheet-like material is added by a nail base and a nail that opens and closes with respect to the nail base.

In a sheet-fed rotary printing press, a claw device comprising a claw that can be opened and closed and a claw base that opposes the claw for transporting the paper one by one is supported on the outer peripheral notch of the rotating drum and the paper discharge chain. It is arranged on the shaft. The nail in this type of nail device must always hold the paper that is fed one by one at the same position, and if the paper holding position is shifted, an error or variation in the pattern position called misregistration may occur. The pattern is printed twice as a double, which causes a decrease in print quality. In order to solve this problem, there is a structure in which a large number of recesses are provided on the holding surface of either the claw or the claw base, rubber is filled in the recess, and the frictional force of the holding surface is increased by this rubber ( For example, see Patent Document 1).
Japanese Utility Model Publication No. 60-157234

  In the nail device in the conventional sheet-fed rotary printing press described above, the pressing force in the direction orthogonal to the surface of the sheet-like material is increased by the frictional force of the rubber, so that the displacement of the holding position of the sheet-like material is regulated to some extent. However, the wear of the rubber itself is relatively fast and inferior in durability, and when a large tensile force is applied to the sheet material in the direction opposite to the conveyance direction, the force that regulates this does not work. There is a problem that the holding position of the sheet-like object is shifted.

  The present invention has been made in view of the above-described conventional problems. The object of the present invention is to shift the holding position of the sheet-like object even when a large tensile force is applied to the sheet-like object in the direction opposite to the conveying direction. Is to provide a nail device for a sheet-fed rotary printing press.

  In order to achieve this object, the present invention provides a nail apparatus in a sheet-fed rotary printing machine that holds a sheet-like material by a nail and a nail base, and a center of the nail holding surface in a direction perpendicular to the sheet-like material conveyance direction. The first protrusion is provided on the portion, and the second protrusion is provided on both ends of the nail holding surface in the direction perpendicular to the sheet-conveying direction. The first protrusion is in contact with the sheet-like object. A portion where the first abutment surface and the first wall surface of the first protrusion on the downstream side in the sheet conveyance direction intersect each other has a corner portion having a right or acute apex, and the second protrusion is A second contact surface that contacts the sheet-like material and a tangent line that contacts a portion that does not contact the sheet-like material when the sheet-like material is added downstream of the second contact surface in the sheet-like material conveyance direction. The angle has an obtuse angle.

  According to the present invention, in the above invention, a corner portion where the second abutting surface and the second wall surface located on the downstream side of the second abutting surface in the sheet conveyance direction has an apex of an obtuse angle It is.

  In the present invention, in the above invention, a portion where the second abutting surface and the second wall surface located on the downstream side of the second abutting surface in the sheet conveyance direction is a curved surface portion.

  The present invention relates to a nail apparatus in a sheet-fed rotary printing press that holds a sheet-like material by a nail and a nail base, and a sheet-like material conveyance direction at a central portion of the nail holding surface perpendicular to the sheet-like material conveyance direction. A first projection that bites into the sheet-like material pulled in the opposite direction, and bites into the sheet-like material when the sheet-like material is replaced at both ends of the nail holding surface in a direction perpendicular to the sheet-like material conveying direction. Is provided with a second protrusion that reduces the amount of the protrusion more than the first protrusion.

  According to the present invention, in the above invention, a plurality of the first protrusions are provided in the sheet-like material conveyance direction and a direction orthogonal to the sheet-like material conveyance direction, and the second protrusions are plural in the sheet-like material conveyance direction. Is provided.

  According to the present invention, in the invention, the second protrusion is provided in the sheet conveyance direction across a plurality of inner rows from both ends in a direction orthogonal to the sheet conveyance direction of the gripping surface of the claw.

  According to the present invention, when the sheet-like object is pulled in the direction opposite to the paper conveyance direction by the first protrusion, the deviation of the holding position of the sheet-like object can be regulated. For this reason, since the sheet-like materials sent one by one are always added at the same position, there is no occurrence of misregistration or double-blurring, and print quality is not deteriorated. In addition, second protrusions that reduce biting into the sheet-like object when the sheet-like object is replaced are provided at both ends of the nail holding surface in a direction orthogonal to the sheet-like object conveyance direction. Thus, the occurrence of scratches on the sheet-like material can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a side view showing a part of an impression cylinder provided with a nail of a nail device in a sheet-fed rotary printing press according to the present invention, FIG. 2 is a side view of the nail, and FIG. 3 is a view taken in the direction of arrow III in FIG. 4 is a sectional view taken along line IV-IV in FIG. 3, FIG. 5 is a sectional view taken along line VV in FIG. 3, and FIG. 6 is also for explaining the reason for restricting the displacement of the holding position of the sheet-like material by the first projection. FIG. 7A shows a state in which a sheet-like object is held by a nail and a claw base, FIG. 7B shows a sectional view of the sheet-like object, and FIG. It is a side view of the principal part for demonstrating the holding change of the general sheet-like material in a printing machine, The figure (A) shows the state which started changing, and the figure (B) shows changing. FIG. 8 shows the relationship between the protrusion and the paper when releasing the paper grip in a sheet-fed rotary printing press. FIG. 9 is a schematic diagram showing the relationship between the thickness of the sheet-like material and the nail of the impression cylinder at the time of holding, and FIG. 10 schematically shows the state of holding the paper in a sheet-fed rotary printing press. FIG. 7B is a view taken in the direction of the arrow X in FIG. 7A, and FIG. 7A shows the state at the time of replacement, and FIG. 7B shows the state after the replacement. 4 and 5, hatching is omitted for convenience of explanation, and for FIG. 9, the claw and claw base of the impression cylinder are hatched for convenience of explanation.

  In a notch 2 provided on the outer periphery of the impression cylinder shown by reference numeral 1 in FIG. 1, a claw shaft 3 extending in the cylinder axis direction of the impression cylinder 1 is rotatably mounted by a bearing not shown. Has been. A claw base 4 formed in an elongated shape extending in the cylinder axis direction of the impression cylinder 1 is fixed to a peripheral end portion of the wall surface of the notch 2 by a plurality of bolts 5. On the claw shaft 3, a plurality of claw devices 6 formed together with the claw base 4 are arranged in parallel in the axial direction. That is, the bracket 7 having the spring receiver 7 a and the stopper receiver 7 b is fixed to the claw shaft 3 by the bolts 8.

  A claw holder 9 includes a spring receiver 9a facing the spring receiver 7a and a stopper 10 facing the stopper receiver 7a and adjustable in advance and retreat, and is adjacent to the bracket 7 and is restricted from moving in the axial direction. The claw shaft 3 is rotatably mounted. A claw spring 11 is provided between the spring receiver 7a and the spring receiver 9a so as to give the claw holder 9 a rotational force in a direction in which they are separated from each other, and the claw holder 9 is rotated by its elastic force. The limit is regulated by the stopper 10. At the free end of the claw holder 9, a claw 13 for holding the paper 12 as a sheet-like material is screwed to the claw base 4, and the claw shaft 3 is reciprocated by a predetermined angle by a cam mechanism (not shown) at the barrel end. By rotating, the claw holder 9 is rotated via the claw spring 11 so that the claw 13 is opened and closed with respect to the claw base 4. The impression cylinder 1 including the paper 12 rotates in the direction of arrow A (paper conveyance direction) in the figure to convey the paper 12. About the nail | claw apparatus provided in the impression cylinder 1 demonstrated above, there is no place especially different from the nail | claw apparatus of the sheet-fed rotary printing machine known conventionally.

  The feature of the present invention is that, as shown in FIG. 3, the first protrusion is formed at the central portion of the holding surface 15 of the claw 13 in the direction (arrow C-D direction) orthogonal to the paper transport direction (arrow A-direction). In addition, a large number of projections 17 are provided, and two types of projections are provided on the holding surface 15 such that a plurality of second projections 18 are provided at both ends 15a and 15a of the holding surface 15 in the direction of arrow CD. That is, as will be described later, a first protrusion 17 that bites into the paper 12 pulled in the direction opposite to the paper transport direction is provided at the center of the gripping surface 15 of the claw 13 in the direction orthogonal to the paper transport direction. A characteristic feature is that second protrusions 18 are provided at both ends of the holding surface 15 in a direction orthogonal to the paper conveyance direction to reduce the biting into the paper 12 when the paper is replaced. A plurality of first protrusions 17 are provided in the sheet-like material conveyance direction (arrow AB direction) and in a direction (arrow CD direction) orthogonal to the sheet-like material conveyance direction, and the second protrusion 18 is A plurality of sheets are provided in the sheet conveyance direction.

  Among these, as shown in FIGS. 3 and 4, the first protrusion 17 is formed in a rectangular shape in plan view and in a trapezoidal shape in side view, and the first contact surface 17a is flat and square in plan view. The wall surface 17b positioned in the arrow B direction (upstream side in the paper conveyance direction) is formed so as to incline in the arrow A direction (downstream side in the paper conveyance direction) from the base (grip surface 15). The wall surface 17c is oriented in the vertical direction with respect to the paper 12 to be conveyed. That is, the angle α formed by the first wall surface 17c and the first contact surface 17a (the conveyed paper 12) is 90 °.

  As shown in FIGS. 3 and 5, the second protrusion 18 is formed in a rectangular shape in plan view and in a trapezoidal shape in side view, and the second contact surface 18a is flat and formed in a square shape in plan view. A wall surface 18b located in the B direction (upstream side in the paper conveyance direction) is formed so as to incline in the arrow A direction (downstream side in the paper conveyance direction) from the base (grip surface 15), and in the arrow A direction (downstream in the paper conveyance direction). The second wall surface 18c located at the side is formed so as to incline in the arrow B direction (upstream side in the paper conveying direction) from the base (the holding surface 15). That is, the downstream side of the second protrusion 18 in the paper conveyance direction is inclined from the base (the gripping surface 15) to the upstream side in the paper conveyance direction. Formed so that the angle β formed by the second wall surface 18c and the second contact surface 18a, which are not in contact with the paper 12 when the paper 12 is gripped by the claw 13, is an obtuse angle (120 ° in this embodiment). Has been.

  Thus, the first protrusion 17 is formed on the holding surface 15 of the claw 13 so that the apex angle α of the corner portion 17d where the first wall surface 17c and the first contact surface 17a intersect each other is 90 °. Therefore, when the paper 12 held and transported by the claw 13 and the claw base 14 is pulled in the direction opposite to the paper transport direction (arrow B direction), the shift of the gripping position of the paper 12 is regulated. be able to. This will be described with reference to FIG. As shown in FIG. 6A, the surface of the paper 12 held between the claw 13 and the claw base 4 is placed on the first contact surface 17a of the first projection 17 as shown in FIG. As a result, a recess 12a is formed. The angle θ formed by the engagement surface 12b formed at the end of the recess 12a in the direction of arrow A and the bottom surface is formed at the same angle 90 ° as the corner 17d of the first protrusion 17. Thus, since both the first wall surface 17c and the engaging surface 12b extend in the direction orthogonal to the arrow B direction, when the paper 12 is pulled in the arrow B direction, the engaging surface 12b is By engaging the first wall surface 17c and the corner portion 17d of the one protrusion 17, the shift of the holding position of the paper 12 can be regulated.

  Here, instead of providing the first protrusion 17 capable of restricting the displacement of the holding position of the paper 12 over the entire holding surface 15 of the claw 13, a part of the holding surface 15, that is, the arrow C of the claw 13 is provided. The reason why the second protrusions 18 are provided at both end portions 15a and 15a in the -D direction will be described below.

  Assuming that the first protrusion 17 is provided on the entire holding surface 15 of the claw 13, the holding is released when the holding of the paper 12 is changed between the impression cylinder 1 and the impression cylinder 1. The first protrusion 17 of the nail 13 may damage the surface of the paper 12. This will be described with reference to FIGS. In FIG. 7A, reference numeral 21 denotes a transfer cylinder which is located on the downstream side of the impression cylinder 1 in the paper conveying direction and rotates in the direction of the arrow G so as to face the impression cylinder 1. 24.

  In such a configuration, in FIG. 7A showing a state in which the transfer of the paper 12 from the impression cylinder 1 to the transfer cylinder 21 is started, the claw 13 of the impression cylinder 1 and the claw 24 of the transfer cylinder 21 are at the same time. The paper 12 is added. When the cylinders 1 and 21 are slightly rotated from this state, the holding of the impression cylinder 1 by the claw 13 of the impression cylinder 1 with respect to the paper 12 is released. Can be replaced only by Since the holding is performed at a position slightly out of phase from the position where the claws 13 and 24 face each other, the holding surface 15 of the claw 13 is only at an angle γ as shown in FIG. Repositioning is performed in an inclined state.

  At this time, the paper 12 is transferred to the claw 24 (both not shown) of the transfer cylinder 21 and is conveyed in the direction of arrow G. On the other hand, the claw 13 of the impression cylinder 1 moves in the arrow A direction opposite to the arrow G. Therefore, since the corner 17d of the first protrusion 17 contacts the surface of the paper 12, the corner 17d formed by an angle of 90 ° between the first wall surface 17c and the first contact surface 17a is formed. The surface of the paper 12 is pierced, and further, the paper 12 is conveyed, so that the paper 12 is scratched.

  This scratch is more likely to occur as the thickness of the paper 12 increases. This will be described with reference to FIG. FIG. 9 shows the relationship between the state in which the nail 13 of the impression cylinder 1 and the nail 23 of the transfer cylinder 21 are simultaneously held, and the distance between the nail 13 and the top surface of the paper 12 when the holding is released from the paper 12. . As shown in the figure, the holding of the paper 12 is changed, and the claw 13 that has released the holding of the paper 12 is separated from the claw base 4 by the same distance as shown by a two-dot chain line regardless of the thickness of the paper 12. . Accordingly, the distances L1 to L3 between the separated claw 13 and the upper surface of the paper 12 are L1> L2> L3, and in the case shown in FIG. Since they are in close proximity, scratches are likely to occur.

  Further, the scratches are remarkably generated at both ends of the claw 13 holding the paper 12. This will be described with reference to FIG. As described above, the holding is performed at a position slightly shifted in phase from the position where the claws 13 and 24 face each other (position moved from FIG. 7A to FIG. 7B). As shown in (A), the claws 13 and 24 are separated from each other in the direction of the arrow EF (this interval is exaggerated in FIG. 8 for convenience of explanation). Yes. The claws 13 and 24 are arranged in a staggered manner in the axial direction (arrow CD direction) of the both cylinders 1 and 21. Therefore, when the paper 12 is replaced, the paper 12 held by the claws 13 and 24 is undulated in the direction of the arrow CD.

  Further, when both the cylinders 1 and 21 are rotated slightly, the claw 13 of the impression cylinder 1 is separated from the claw base 4 (the claw 3 is opened) as shown in FIG. Since the paper 12 to be replaced by the claw 24 of the transfer cylinder 21 is pulled in the direction of arrow F, the paper 12 from which the grip is released from the claw 13 is formed at both ends 15a of the holding surface 15 of the claw 13 in the direction of arrow CD. 15a, the tensile force is concentrated. For this reason, at both ends 15a, 15a, the corners 17d of the first protrusions 17 are pierced into the surface of the paper 12, and thereafter the impression cylinder 1 rotates in the direction of arrow A, so that both ends Scratches are likely to occur in the portions 15a and 15a.

  In the present invention, the second protrusions 18 formed so that the angle β formed between the second contact surface 18a and the second wall surface 18c is an obtuse angle at both ends 15a, 15a. For this reason, even if the paper 12 whose grip is released from the claw 13 is pulled relatively strongly in the direction of the arrow B, as shown in FIG. 5, the corners 18d of the second protrusions 18 are formed at both ends 15a and 15a. Since it becomes difficult to slip on the surface of the paper 12, even if the impression cylinder 1 rotates in the direction of arrow A thereafter, the occurrence of scratches at the both end portions 15a and 15a can be reduced. Therefore, the paper 12 loaded in the paper discharge device does not become uneven, and the commercial value of the paper itself does not deteriorate due to scratches.

  In this manner, the first protrusion 17 having the first wall surface 17c oriented in the vertical direction toward the paper 12 conveyed downstream in the paper conveyance direction is provided on the holding surface 15 of the claw 13. As a result, even if the paper 12 is pulled in the direction opposite to the transport direction, the displacement of the holding position of the paper 12 can be regulated by the first protrusions 17. Further, second protrusions 18 having obtuse corners 18d that are hard to stick to the surface of the paper 12 are provided at both end portions 15a and 15a of the gripping surface 15 where the pulling force of the paper 12 is most concentrated by the nail to be replaced. As a result, scratches generated on the surface of the paper 12 when the paper 12 is replaced can be reduced.

  FIG. 11 is a plan view of a nail holding surface showing a modified example of the distribution of the first and second protrusions in the nail device in the sheet-fed rotary printing press according to the present invention. In this modification, the second protrusions 18 are provided in the paper transport direction across the two inner rows from both ends in the direction perpendicular to the paper transport direction of the holding surface 15 of the claw 13. Even in this modification, even if the paper 12 is pulled in the direction opposite to the transport direction, the first protrusion 17 can regulate the shift of the holding position of the paper 12 and the second protrusion 18 is provided. As a result, scratches generated on the surface of the paper 12 when the paper 12 is replaced can be reduced. In this modification, the second protrusions 18 are arranged in two rows, but may be arranged in three rows or more as necessary.

  FIG. 12 is a side view of the main part showing a modification of the first protrusion. In the figure, the first projection indicated by reference numeral 31 has a first abutting surface 31a that is flat and has a square shape in plan view, and a wall surface 31b that is positioned in the direction of arrow B (upstream in the paper conveyance direction). The wall surface 31c in the direction of arrow A is formed so as to incline in the direction of arrow A (downstream in the paper conveyance direction). That is, the angle α formed by the wall surface 31c and the first contact surface 31a is formed to be an acute angle.

  By being configured in this way, as shown in FIG. 13A, the surface of the paper 12 held on the claw 13 and the claw base 4 has a first surface as shown in FIG. A recess 12 a is formed by the first contact surface 31 a of the protrusion 31. The angle θ formed between the engagement surface 12b formed at the end of the recess 12a in the arrow A direction and the bottom surface is 90 ° because the corner 17d of the first protrusion 17 is formed at an acute angle. . Thus, since the engaging surface 12b extends in the direction orthogonal to the arrow B direction, when the paper 12 is pulled in the arrow B direction, the engaging surface 12b becomes the corner portion 31d of the first protrusion 31. The displacement of the holding position of the paper 12 can be regulated by engaging with.

  FIG. 14 is a side view of the main part showing a modification of the second protrusion. In FIG. 2A, the second protrusion indicated by reference numeral 32 has a flat second contact surface 32a that contacts the paper 12, and is formed in a square shape in plan view. The paper on the second contact surface 32a A curved surface portion 32b that is formed in a curved shape that does not come into contact with the paper 12 when the paper 12 is added on the downstream side in the conveyance direction (the direction of the arrow A) is provided. The wall surface 32c in the direction of arrow B is inclined from the base portion in the direction of arrow A, and the second wall surface 32d in the direction of arrow A is inclined in the direction of arrow A from the base portion. The angle β formed between the tangent line T in contact with the curved surface portion 32b and the second contact surface 32a is formed as an obtuse angle. As described above, since the angle β formed between the tangent line T in contact with the curved surface portion 32b and the second contact surface 32a is formed to be an obtuse angle, the curved surface portion 32b is formed on the paper 12 when the paper 12 is replaced. Since there is no piercing on the surface, the paper 12 will not be scratched even if the impression cylinder 1 rotates in the direction of arrow A thereafter.

  In FIG. 5B, the second protrusion indicated by reference numeral 33 has a flat second contact surface 33a that contacts the paper 12 and is formed in a square shape in plan view. A curved surface portion 33b formed in a curved shape that does not come into contact with the paper 12 when the paper 12 is held on the downstream side in the conveyance direction (direction of arrow A) is provided. Further, the wall surface 33c in the direction of arrow B is inclined in the direction of arrow A from the base, and the second wall surface 33d in the direction of arrow A is oriented in the vertical direction with respect to the paper 12 to be conveyed. The angle β formed between the tangent line T in contact with the curved surface portion 33b and the second contact surface 33a is formed as an obtuse angle. As described above, the angle β formed between the tangent line T in contact with the curved surface portion 33b and the second contact surface 33a is formed to be an obtuse angle, so that the curved surface portion 33b can be Since there is no piercing on the surface, the paper 12 will not be scratched even if the impression cylinder 1 rotates in the direction of arrow A thereafter.

It is a side view which shows a part of impression cylinder provided with the nail | claw of the nail | claw apparatus in the sheet-fed rotary printing press which concerns on this invention. It is a side view of a nail in a nail device in a sheet-fed rotary printing press concerning the present invention. FIG. 3 is a view taken in the direction of arrow III in FIG. 2. It is the IV-IV sectional view taken on the line in FIG. It is the VV sectional view taken on the line in FIG. The nail | claw apparatus in the sheet-fed rotary printing press which concerns on this invention is an enlarged view of the principal part for demonstrating the reason which controls the shift | offset | difference of the holding position of the sheet-like material by the 1st protrusion, The figure (A) is a nail | claw. A state in which the sheet-like object is held by the claw stand is shown, and FIG. 5B is a cross-sectional view of the sheet-like object. It is a side view of the principal part for demonstrating the holding change of the general sheet-like material in a sheet-fed rotary printing machine, The figure (A) shows the state which started the holding change, and the figure (B). Shows the state of changing the mouth. FIG. 3 is an enlarged view of a main part showing a relationship between a protrusion and paper when releasing a paper grip in a sheet-fed rotary printing press. In the nail apparatus in the sheet-fed rotary printing press which concerns on this invention, it is a schematic diagram which shows the relationship between the thickness of the sheet-like material at the time of holding change, and the nail | claw of an impression cylinder. FIG. 8 is a view taken in the direction of arrow X in FIG. 7B schematically showing a state of paper replacement in a sheet-fed rotary printing press. In the nail device in the sheet-fed rotary printing press according to the present invention, it is a plan view of the nail gripping surface showing a modified example of the distribution of the first and second protrusions. In the nail device in the sheet-fed rotary printing press which concerns on this invention, it is a side view of the principal part which shows the modification of a 1st protrusion. The nail | claw apparatus in the sheet-fed rotary printing press which concerns on this invention WHEREIN: It is an enlarged view of the principal part for demonstrating the reason which controls the shift | offset | difference of the holding position of the sheet-like material by the modification of a 1st protrusion. ) Shows a state in which the sheet-like object is held by the nail and the nail base, and FIG. 5B is a cross-sectional view of the sheet-like object. FIGS. 7A and 7B are side views of the main part showing a modification of the second protrusion in the nail device in the sheet-fed rotary printing press according to the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Impression cylinder, 4 ... Claw stand, 6 ... Claw device, 13 ... Claw, 15 ... Holding surface, 15a ... Both ends, 17, 31 ... 1st protrusion, 17a, 31a ... 1st contact surface, 17c , 31c ... first wall surface, 17d ... corner, 18, 32, 33 ... second protrusion, 18a, 32a, 33a ... second contact surface, 18c, 32d, 33d ... second wall surface, 32b, 33b: Curved surface portion.

Claims (6)

In a nail device in a sheet-fed rotary printing machine that adds a sheet-like material with a nail and a nail base,
A first protrusion is provided at a central portion of the nail holding surface in a direction orthogonal to the sheet conveyance direction, and a second protrusion is formed at both ends of the nail holding surface in a direction orthogonal to the sheet conveyance direction. Provided,
In the first protrusion, a portion where the first contact surface that contacts the sheet-like object and the first wall surface on the downstream side of the first protrusion in the sheet-like object conveyance direction has a right-angled or acute vertex. Having a corner with
The second protrusion does not contact the sheet-like object when the sheet-like object is held on the second contact surface that contacts the sheet-like object and on the downstream side of the second contact surface in the sheet-like object conveying direction. A nail device in a sheet-fed rotary printing press, characterized in that an angle formed with a tangent line in contact with a part has an obtuse angle.   The portion where the second contact surface and the second wall surface located on the downstream side in the sheet conveyance direction of the second contact surface are corner portions having an obtuse apex. Item 2. A nail device for a sheet-fed rotary printing press according to item 1.   2. The sheet according to claim 1, wherein a portion where the second contact surface and the second wall surface located on the downstream side in the sheet conveyance direction of the second contact surface intersect is a curved surface portion. Nail device in a leaf rotary printing press. In a nail device in a sheet-fed rotary printing machine that adds a sheet-like material with a nail and a nail base,
A first protrusion that bites into a sheet-like material pulled in a direction opposite to the sheet-like material conveyance direction is provided at a central portion of the nail holding surface in a direction perpendicular to the sheet-like material conveyance direction;
Provided at both ends of the nail holding surface in a direction orthogonal to the sheet-like material conveying direction are second protrusions that reduce biting into the sheet-like material when the sheet-like material is replaced, compared to the first protrusions. A nail device for a sheet-fed rotary printing press. A plurality of the first protrusions are provided in the sheet conveyance direction and a direction orthogonal to the sheet conveyance direction,
5. The nail device for a sheet-fed rotary printing press according to claim 4, wherein a plurality of the second protrusions are provided in the sheet-like material conveyance direction.   The said 2nd protrusion is provided in the sheet-like material conveyance direction over the inner side multiple rows from the both ends of the direction orthogonal to the sheet-like material conveyance direction of the nail | claw holding surface. Nail device in a sheet-fed rotary printing press.

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