JP4410534B2 - Paper holding device and printing apparatus having the same - Google Patents

Description

  The present invention relates to a printing apparatus having an impression cylinder and a paper holding apparatus that is provided in such a printing apparatus and engages a sheet with the impression cylinder, and in particular, prevents the sheet from floating when the sheet is latched. The present invention relates to a printing apparatus and a sheet holding apparatus.

  Conventionally, printing apparatuses have been used for the purpose of printing a large number of sheets. As a printing apparatus, for example, as described in [Patent Document 1] and [Patent Document 2], a sheet is placed between a plate cylinder, an impression cylinder disposed opposite thereto, and the impression cylinder. 2. Description of the Related Art A printing apparatus including a paper holding device that locks is known. In such a printing apparatus, the leading edge of the paper is locked with the plate cylinder by a locking member called a paper supply clamper provided in the paper holding device.

  In order to prevent breakage of the locking member itself and the plate cylinder, and in the case where the printing apparatus is a stencil printing apparatus, in order to prevent damage to the master wound on the plate cylinder and prevent the occurrence of abnormal images, The locking member needs to be disposed so as not to contact the plate cylinder at a position close to the plate cylinder. On the other hand, the locking portion, that is, the gripping position, which is provided in the locking member and locks the leading edge of the paper with the impression cylinder, is on the outer peripheral surface of the impression cylinder from the viewpoint of preventing deformation of the paper. Ideally located.

However, when the gripping position is located on the outer peripheral surface of the impression cylinder, the locking member has a certain size and thickness, and thus comes into contact with the plate cylinder or the master, and the locking member and the plate A trunk | drum etc. will be damaged.
Therefore, conventionally, as described in [Patent Document 1] and [Patent Document 2], a recess is provided in the impression cylinder, and the locking member is configured to lock the paper between the impression cylinder. In the position, the entirety is accommodated in the recess and is located below the outer peripheral surface of the impression cylinder.

JP 2000-239400 A JP 2002-137363 A

  However, when such a configuration is adopted, the gripping position is also located below the outer peripheral surface of the impression cylinder. Therefore, the edge portion formed on the outer peripheral surface of the impression cylinder by using paper as a beam and providing a recess is a fulcrum. With the gripping position as the power point, the paper floats from the outer peripheral surface of the impression cylinder, causing the paper to bend, and when printing, the paper reaches the plate cylinder or master before reaching the assumed printing position. There has been a problem of an abnormal image in which an abnormal image called a double image is formed due to contact and a double printed image is formed, or an abnormal image in which ink is rubbed is generated. In addition, when the paper contacts the master, the master is stressed, and when the master is damaged, there is a problem that an abnormal image, commonly referred to as grain, is generated. Note that the damage to the master is more likely to occur as the number of printed sheets increases.

  In addition, as described in [Patent Document 1] and [Patent Document 2], a locking member closing operation, that is, an operation for locking the sheet with the impression cylinder is performed. The stopping member is driven by a cam disposed in the vicinity of the impression cylinder, and the closing position of the locking member is determined by the shape of the cam, but the member that supports the locking member The shape of the cam or the like varies within tolerances due to manufacturing, and this variation or accumulation of variations causes variations in the closing amount or closing position of the locking member for each product. If it does so, the amount of the above-mentioned floating of the paper and the amount of deflection will also vary, resulting in a product in which the same problems as described above will occur remarkably.

  The present invention relates to a paper holding device that is provided in a printing apparatus having an impression cylinder and that locks the paper between the impression cylinder and a printing apparatus including the same, and prevents the damage of the plate cylinder and the like while It is an object of the present invention to provide a printing apparatus and a sheet holding apparatus that prevent problems caused by the floating of the sheet at the time of locking.

In order to achieve the above object, the invention according to claim 1 is provided with a locking member that moves integrally with the impression cylinder, and includes a locking part for locking the leading end of the paper with the impression cylinder, As a locking state for locking the leading end of the sheet to the locking member, the position where the locking portion protrudes from the position on the substantially circumferential surface of the pressure drum or this position. A locking member displacing means for providing a first locking position occupied and a second locking position where the entirety of the locking member is substantially equal to the circumferential surface of the impression cylinder or submerged from the circumferential surface; Yes, and the locking member displacement means engages with the engaging member itself or the locking member and the integral member, the first engagement for causing the locking member to the first engagement state position and engaging portion, in the sheet holding device for perforated and a second engagement portion for the engaging member to the second locking condition position.

  According to a second aspect of the present invention, in the paper holding device according to the first aspect, the timing at which the locking member displacing means displaces the locking member from the first locking state to the second locking state. If the locking member continues to occupy the first locking position, it is characterized in that it is immediately before the locking member engages with a member at a position facing the impression cylinder.

According to a third aspect of the present invention, in the sheet holding device according to the first or second aspect , if the second engagement portion is configured so that the locking member continues to occupy the first locking state, The member is formed by a member that is engaged with the member and that is in a position facing the impression cylinder.

According to a fourth aspect of the present invention, in the paper holding device according to the third aspect , the member at a position facing the impression cylinder is a plate cylinder.

According to a fifth aspect of the present invention, in the paper holding device according to the fourth aspect , the second engaging portion is constituted by a non-opening portion of the plate cylinder.

According to a sixth aspect of the present invention, in the paper holding device according to the first or second aspect , the second engaging portion is constituted by a member occupying a fixed position.

According to a seventh aspect, the sheet holding device according to any one of claims 1 to 6, the first engaging portion, characterized in that it is constituted by a member occupying a fixed position.

The invention of claim 8, wherein, in the sheet holding device according to any one of claims 1 to 7, having a second engagement portion, in a position corresponding to both end portions in the width direction of the locking member It is characterized by that.

According to a ninth aspect of the present invention, in the paper holding device according to any one of the first to eighth aspects, the locking member displacing means is disposed between the locking member and the impression cylinder. Is provided with an open position for receiving the leading edge of the paper.

According to a tenth aspect of the present invention, in the paper holding device according to the ninth aspect , the locking member displacing means engages the locking member itself or a member integral with the locking member, and the locking member is It has the 3rd engaging part for making it the said open state.

According to an eleventh aspect of the present invention, the leading edge of the sheet is provided between the sheet holding device according to any one of the first to tenth aspects and the locking portion of the locking member provided in the sheet holding device. A printing apparatus having an impression cylinder that locks a portion and a plate cylinder arranged to face the impression cylinder.

The present invention includes a locking member that is provided with a locking portion for locking the leading end of a sheet to and from the impression cylinder, and that moves together with the impression cylinder. As the locking position for locking the leading edge of the paper, the first locking position where the locking portion occupies a position on the substantially circumferential surface of the impression cylinder or a position protruding from this position is the same as the first locking position. whole possess a locking member displacement means for providing a second locking condition position that sinks from the position approximately equal to or this circumferential surface and the peripheral surface of the impression cylinder of the locking member, is the locking member displacement means, A first engaging portion for engaging the locking member itself or a member integral with the locking member to bring the locking member into a first locking state, and a second locking member. because of the sheet holding device for perforated and a second engagement portion for the locking state position, the first engagement portion and the second engaging portion by respective roles, the plate Trunk and While preventing the breakage of the stopping means, the abnormal image referred to as image doubling due to the floating and bending of the paper when the paper is locked, the abnormal image where the ink is rubbed, the printing device equipped with the paper holding device is the master It is possible to provide a sheet holding device that can satisfactorily prevent malfunctions such as an abnormal image, which is commonly referred to as grain, caused by a master damage due to a stress on the master in the case of the type using the.

  If the timing at which the locking member displacing means displaces the locking member from the first locking position to the second locking position is assumed that the locking member continues to occupy the first locking position. If it is immediately before the locking member is engaged with a member located at a position facing the impression cylinder, the plate cylinder and the locking means are prevented from being damaged, and the paper floats and bends when the paper is locked. An abnormal image that is called image duplication due to ink, an abnormal image that is in a state where ink is rubbed, a master damage caused by stress on the master when the printing device equipped with the paper holding device is a type that uses the master, the master Therefore, it is possible to provide a sheet holding device that can satisfactorily prevent problems such as abnormal images, which are commonly referred to as grain, caused by breakage of the sheet.

  The second engaging portion is constituted by a member at a position facing the impression cylinder, which is engaged with the locking member if the locking member continues to occupy the first locking position. Then, the locking member is displaced from the first locking state to the second locking state by the member located at the position facing the impression cylinder, and therefore the timing of this displacement can be set strictly. An abnormal image called an image doubling due to paper floating and bending at the time of paper locking, an abnormal image in which ink is rubbed, and a paper holding device, while preventing damage to the plate cylinder and the locking means When the installed printing device is a type that uses a master, it is possible to very well prevent problems such as damage to the master caused by stress on the master and abnormal images such as commonly called graininess caused by damage to the master. Arise Goods can be provided a sheet holding device can also be prevented that rarely occurs.

  If the member facing the impression cylinder is the plate cylinder, the image cylinder caused by the floating and bending of the paper when the paper is locked while preventing the plate cylinder and the locking means from being damaged. An abnormal image that appears when the ink is rubbed, especially when the printing device equipped with a paper holding device is a type that uses a master, the master is damaged due to stress on the master, or the master is damaged. It is possible to provide a sheet holding device that can prevent a malfunction such as an abnormal image, which is commonly referred to as grain, and can prevent the occurrence of a product in which such a malfunction occurs.

  If the second engaging portion is constituted by a non-opening portion of the plate cylinder, the plate cylinder and the locking means are prevented from being damaged, and the sheet is lifted and bent when the paper is locked. An abnormal image called image duplication caused by the image, an abnormal image in which the ink is rubbed, particularly when the printing device equipped with the paper holding device is a type using a master, the master is damaged due to stress on the master, It is possible to prevent problems such as abnormal images, which are commonly referred to as grain, caused by breakage of the master, and to prevent rare occurrence of products in which such problems occur. Further, the locking member is moved from the first position to the second position. Even if the member displaced in the state is engaged with the plate cylinder, it is possible to provide a paper holding device that can prevent ink from leaking from the plate cylinder by this engagement.

  If the second engaging portion is constituted by a member occupying a fixed position, the first engaging portion and the second engaging portion capable of a relatively simple configuration are respectively provided. By preventing the damage of the plate cylinder and the locking means, the abnormal image referred to as image doubling due to the floating and bending of the paper when the paper is locked, and the abnormal image where the ink is rubbed When a printing apparatus equipped with a paper holding device is a type using a master, it is possible to satisfactorily prevent problems such as damage to the master due to stress on the master and abnormal images, commonly referred to as grain, caused by damage to the master. A sheet holding device can be provided.

  If the first engaging portion is constituted by a member occupying a fixed position, the first engaging portion and the second engaging portion, which can be made relatively simple, respectively, By preventing the damage of the plate cylinder and the locking means, the abnormal image referred to as image doubling due to the floating and bending of the paper when the paper is locked, and the abnormal image where the ink is rubbed When a printing apparatus equipped with a paper holding device is a type using a master, it is possible to satisfactorily prevent problems such as damage to the master due to stress on the master and abnormal images, commonly referred to as grain, caused by damage to the master. A sheet holding device can be provided.

  Assuming that the second engaging portion has positions corresponding to both end portions in the width direction of the locking member, the first engaging portion and the second engaging portion play their respective roles. Since the locking member is prevented from being twisted when the second engaging portion is actuated, the plate cylinder and the locking means are satisfactorily prevented, and the paper is lifted and bent when the paper is locked. Abnormal image called image duplication, abnormal image where ink is rubbed, master damage due to stress on master when the printing device equipped with paper holding device is a type that uses master, damage due to master damage It is possible to provide a sheet holding device that can prevent problems such as abnormal images, which are commonly referred to as “grained”, from occurring.

  If the locking member displacing means gives the locking member an open position for receiving the leading end portion of the paper between the locking member and the impression cylinder, the locking cylinder displacing means causes the plate cylinder to move. And an abnormal image referred to as an image double caused by the floating and bending of the paper when the paper is locked, an abnormal image in which the ink is rubbed, and a printing device equipped with the paper holding device In the case of a type that uses a master, it is possible to prevent problems such as damage to the master due to stress on the master, abnormal images such as commonly called graininess caused by damage to the master, and to give the locking member an open position In addition, it is possible to provide a sheet holding device capable of providing a locking position and an opening position by a locking member displacing means having a relatively simple structure with a small space.

  If the locking member displacing means has a third engaging portion for engaging with the locking member itself or a member integral with the locking member, and bringing the locking member into an open state, The third engagement portion provided in the locking member displacing means plays a role, thereby preventing the plate cylinder and the locking means from being damaged, and an image resulting from the floating and bending of the paper when the paper is locked. An abnormal image called double, an abnormal image in which ink is rubbed, or when the printing device equipped with a paper holding device is a type that uses a master, the master is damaged due to stress on the master, or the master is damaged. It is possible to prevent problems such as abnormal images, commonly referred to as grain, and to give the locking member an open position, and the locking position and the open state are provided by a relatively small and simple configuration of the locking member displacement means. It is possible to provide a sheet holding device that can provide and.

According to the present invention, the leading end portion of the paper is locked between the paper holding device according to any one of claims 1 to 11 and the locking portion of the locking member provided in the paper holding device. A printing cylinder having an impression cylinder and a plate cylinder arranged opposite to the impression cylinder, so that it has a paper holding device that exhibits the above-mentioned effects and prevents damage to the printing cylinder and the locking means. On the other hand, when the paper is locked up, when the paper is lifted, an abnormal image called image doubling due to bending, an abnormal image that is rubbed with ink, or when the printing device equipped with the paper holding device is a type that uses a master Can prevent problems such as damage to the master due to stress on the master, abnormal images called graininess, etc. caused by damage to the master, can perform good printing, has a long life, and is trusted by users High quality It is possible to provide a printing apparatus.

  In the sheet holding device in which the second engaging portion and the member integrated with the locking member are engaged, a portion of the member integrated with the locking member that engages with the second engaging portion is If the locking member occupies a position protruding 0.3 to 0.8 mm from the locking member, the locking member is moved from the first locking position to the second locking position by the member located at the position facing the impression cylinder. Since it is displaced to the stop position, the timing of this displacement can be set more strictly together with the amount of displacement, and the paper can be lifted and bent when the paper is locked while preventing damage to the plate cylinder and the locking means. An abnormal image that is called image duplication due to ink, an abnormal image that is in a state where ink is rubbed, a master damage caused by stress on the master when the printing device equipped with the paper holding device is a type that uses the master, the master Caused by damage Grain and abnormal images such as malfunction of the can furthermore satisfactorily prevented called, is such a problem arises products can provide a sheet holding device can also be prevented that rarely occurs.

  FIG. 1 shows an outline of a stencil printing apparatus integrated with a thermal digital plate making as a printing apparatus to which the present invention is applied. The stencil printing apparatus 100 includes an image scanner 61 for reading a document image on the upper part of the apparatus main body 67. The image scanner 61 includes a lamp 63 for illuminating a document set on a contact glass 62, a plurality of mirrors 64, an imaging lens 65, a one-dimensional array CCD 66, and the like.

  The stencil printing apparatus 100 includes a printing unit 69 centering on a rotatable plate cylinder 68 and a master 70 having been made by punching a heat-sensitive stencil sheet 70 a at the lower part of the image scanner 61. And a plate making apparatus 71 for supplying to the plate. The stencil printing apparatus 100 includes an impression cylinder 20 that presses a printing paper P as a paper to be fed against the printing cylinder 68 on the outer periphery of the printing drum 68, and a releasable peeling claw that peels the printing paper P from the printing cylinder 68. 75 and a plate discharging device 76 for peeling the used master 70 wound around the plate cylinder 68 before the printing process.

  The stencil printing apparatus 100 also includes a paper feeding device 52 that supplies the printing paper P toward the printing unit 69 and a paper discharge claw that guides the printing paper P printed on the printing unit 69 away from the impression cylinder 20. 44, a paper transport device 84 for transporting the print paper P guided by the paper discharge claw 44, and a paper discharge tray as a paper discharge tray for stacking the printed print paper P transported by the paper transport device 84 85 and a paper holding device 1 as a paper holding means for holding the printing paper P between the pressure drum 20 and the printing paper P shown in FIG.

  As shown in FIG. 1, a plate cylinder 68 includes an ink supply mechanism (not shown) including an ink roller 72 disposed therein, and an end portion of a master 70 that has been preliminarily disposed at a part of the outer periphery thereof. An openable / closable clamp 73 for gripping, a porous support cylinder (not shown) having an opening and a non-opening (not shown), and a mesh screen (not shown) covering the outer periphery of the porous support cylinder. Yes. The opening is a portion in which a large number of small holes for transmitting ink supplied by the ink supply mechanism are formed, and the transmitted ink is configured to ooze from the screen. The plate cylinder 68 is shown in FIG. 1 via a drive system (not shown) of the plate cylinder 68 including a main motor (not shown) as a plate cylinder drive means so that the rotation speed can be changed corresponding to a plurality of printing speeds. It is driven to rotate in the clockwise direction.

  The impression cylinder 20 is located below the plate cylinder 68. The impression cylinder 20 has substantially the same diameter as the diameter of the plate cylinder 68. The outer peripheral portion includes a cylindrical portion 22 that can come into contact with the outer peripheral surface of the plate cylinder 68 and a concave portion 21 that is recessed with respect to the peripheral surface of the cylindrical portion 22. The clamper base 6 shown in FIG. 4B is fixed to the recess 21. The impression cylinder 20 is made of a synthetic resin in the main body portion to reduce the weight, and nitrile rubber is wound around the outer periphery of the cylindrical portion 22 to reduce uneven rotation of the impression cylinder 20. Yes.

  The drive system of the impression cylinder 20 is connected to the drive system of the plate cylinder 68, and the main motor also serves as drive means for rotationally driving the impression cylinder 20. The impression cylinder 20 is rotationally driven in the counterclockwise direction in FIG. 1 at the same peripheral speed as that of the plate cylinder 68 via a drive system of the impression cylinder 20 including a main motor. The impression cylinder 20 presses the printing paper P against the master 70 wound around the printing cylinder 68 at the nip portion N that is opposite to the printing cylinder 68, and adheres ink oozing from the master 70 to the printing paper P. Printing is performed. The impression cylinder 20 can be brought into and out of contact with the outer peripheral surface of the plate cylinder 68 by contact / separation means (not shown).

The plate making apparatus 71 includes a platen roller 77 and a thermal head 78 as a plate making head disposed so as to be in contact with and away from the platen roller, a roller pair 79 for conveying the plate making master 70 toward the plate cylinder 68, and the plate making master 20. And a cutter 80 for cutting the sheet into a predetermined length. The master 70 made by the plate making apparatus 71 is wound around the plate cylinder 68 so as to cover the opening of the porous support cylinder provided in the plate cylinder 68.
The plate removal device 76 peels off the master 70 from the plate cylinder 68 and conveys it, and the plate removal box 54 that stores the used master 70 that has been peeled off and conveyed from the plate cylinder 68 by the master peeling device 53. And have.

  The sheet feeding device 52 is synchronized with the rotational movement of the sheet feed table 81 on which the printing paper P provided so as to be movable up and down, the sheet feed roller 82 disposed above the sheet feed table 81, and the plate cylinder 68 are rotated. A registration roller pair 83 that feeds the printing paper P fed by the paper feed roller 82 to the printing unit 69, and guides the printing paper P fed by the paper feed roller 82 to the registration roller pair 83. Guide plates 40 and 41 for guiding the printing paper P fed from the resist roller pair 83 toward the printing unit 69 to the printing unit 69 are provided. The paper feed roller 82 feeds the uppermost print paper P among the print papers P stacked on the paper feed table 31 and is rotated at a fixed position. The sheet feed table 81 is controlled to be raised and lowered according to the number of print sheets P so that the uppermost print sheet P contacts the sheet feed roller 82.

The sheet conveying device 84 includes a driving roller 55 and a driven roller 56, a conveying belt 57 as a paper discharge belt wound around the driving roller 55 and the driven roller 56, and an adsorption for adsorbing the printing sheet P on the conveying belt 57. And a fan 58.
The paper discharge table 35 is for discharging the print paper P after printing by the printing unit 69 and holding the print paper P in layers.

  As shown in FIGS. 2 to 8, the sheet holding device 1 has a sheet feeding clamper 2 as an openable / closable locking member for locking the leading end portion of the printing paper P with the impression cylinder 20. ing. 4 (b), 6 (b), and 7 (b), the paper feed clamper 2 engages the lower surface of the front end portion thereof with a 2-3 mm portion of the front end portion of the printing paper P. And it has as the clamp part 2a as a latching | locking part clamped. In each figure after FIG. 2, the code | symbol 20a has shown the outer peripheral surface of the impression cylinder 20, in other words, the position of the peripheral surface.

  As shown in FIG. 2 or FIG. 6, the paper holding device 1 is in a first open state in which the paper feeding clamper 2 receives the leading end of the printing paper P between the paper feeding clamper 2 and the impression cylinder 20. As a locking position for locking the leading end of the printing paper P between the position A and the impression cylinder 20, the clamp portion 2a protrudes from a position on the substantially circumferential surface of the impression cylinder 20 or from this position. A state B as a first locking state that occupies the position, and a state as a second locking state in which the entire sheet feeding clamper 2 sinks from the circumferential surface of the impression cylinder 20 and is stored in the recess 21. It is possible to give the position C and the position D as the second open position for discharging the leading end portion of the printing paper P from between the sheet clamper 2 and the impression cylinder 20. Therefore, the locking position where the paper feed clamper 2 locks the leading edge of the printing paper P, in other words, the gripping position where the leading edge of the printing paper P is gripped is the position B and the printing paper P where the leading edge of the printing paper P is pressed. It is a two-stage with the position C which pinches the front-end | tip.

  Each of the positions A to D is given by an opening / closing mechanism 19 provided in the sheet holding device 1 as a locking member displacing means that is a mechanism for opening and closing the sheet feeding clamper 2. In addition to the opening / closing mechanism 19, the sheet holding device 1 has a floating mechanism 27 for floating the leading end of the printing paper P from the peripheral surface 20 a of the impression cylinder 20 when the paper supply clamper 2 occupies the position D. is doing.

  As shown in FIG. 2, the opening / closing mechanism 19 fixes the clamper arm 4 for supporting the paper feed clamper 2, the central portion of the clamper arm 4, and the base end of the paper feed clamper 2, and the clamper base 6 The clamper shaft 3 is rotatably supported by a predetermined angle, and is rotatably supported by a shaft 4a fixed to one end of the clamper arm 4, and is integrated with the sheet feeding clamper 2 via the clamper arm 4 and the shaft 4a. A roller as a rotating body that is rotatably supported by a roller-shaped clamper cam follower 5 and a shaft 4b fixed to the other end of the clamper arm 4, and is integrated with the sheet feeding clamper 2 via the clamper arm 4 and the shaft 4b. 90.

  The opening / closing mechanism 19 is also fixed at a fixed position and is engaged with the clamper cam follower 5, and a first engagement portion for engaging the roller 90 and bringing the sheet supply clamper 2 to the state B. And a biasing means which is wound around the clamper shaft 3 and biases the sheet feeding clamper 2 so as to always open, and biases the clamper cam follower 5 so as to always press against the cam 8 for the sheet feeding clamper. And a torsion spring 7 shown in FIG.

  As shown in FIG. 7, the clamper base 6 has a substantially casing shape, and is integrally formed of, for example, a synthetic resin or a metal such as aluminum. At the upper upstream end in the rotation direction of the impression cylinder 20 in the clamper base 6, the leading edge of the printing paper P is clamped when the leading edge of the printing paper P is clamped between the clamping portion 2 a and the impression cylinder 20 of the paper feeding clamper 2. A sheet receiving surface 6a for receiving the sheet is formed.

  The paper feed clamper 2 is formed of a thin stainless steel plate as an elastic member having a predetermined elasticity that can absorb errors in accuracy such as the paper clamper cam 8 itself. The sheet feeding clamper 2 is made of a stainless steel plate having a thickness of 0.3 to 0.5 mm, and has a predetermined elasticity. In addition to the clamp portion 2a, the paper feed clamper 2 determines the position by abutting the leading edge of the printing paper P fed from the registration roller pair 83 shown in FIG. 1, as shown in FIG. It has a stopper portion 2b. As shown in FIG. 5, a plurality of stopper portions 2b are formed intermittently in the width direction of the paper feed clamp 2, that is, in the left-right direction in FIG.

  The torsion spring 7 is wound around the clamper shaft 3, and one end of the torsion spring 7 is hooked on the back surface of the paper feed clamper 2 and the other end is hooked on the upper side wall on the front side of the clamper base 6. It is biased in the direction. A required clamping force within a predetermined range is generated between the sheet feeding clamper 2 and the sheet receiving surface 6a due to the elasticity of the sheet feeding clamper 2 and the cam shape of the sheet feeding clamper cam 8 described later. .

  The sheet clamper cam 8 is integrally formed of synthetic resin or metal, and is fixed to a side plate (not shown) on the main body 67 side that occupies a position near the impression cylinder 20. The sheet clamper cam 8 has a configuration and function as a locking member cam that converts the rotational movement of the impression cylinder 20 into an opening / closing operation of the sheet clamper 2 at a predetermined timing and transmits it. A cam shape for opening and closing the paper supply clamper 2 is formed in the paper supply clamper cam 8.

  In other words, the paper feed clamper cam 8 is engaged with the clamper cam follower 5 at the time of paper feed, and a small diameter portion 8a as a third engaging portion for controlling the paper feed clamper 2 to occupy the state A. An intermediate diameter portion 8b as a first engaging portion for engaging with the clamper cam follower 5 at an initial stage when the printing paper is locked and controlling the paper feeding clamper 2 to occupy the position B; A large-diameter portion 8c that allows the clamper cam follower 5 to pass when the paper feed clamper 2 passes through the nip portion N at the time of locking and the paper feed clamper 2 to occupy the position C, and a clamper at the time of paper discharge It has a small-diameter portion 8d as a fourth engaging portion for engaging with the cam follower 5 and controlling the sheet feeding clamper 2 to occupy the position D.

  The small diameter portion 8a is formed at a predetermined position near the upstream side of the nip portion N in the rotation direction of the impression cylinder 20, and opens most when the sheet feeding clamper 2 occupies the sheet feeding position. The diameter is gradually increased so as to be smaller. The medium diameter portion 8 b is formed continuously downstream of the small diameter portion 8 a in the rotation direction of the impression cylinder 20, and the clamp portion 2 a of the sheet feeding clamper 2 is on substantially the same surface as the peripheral surface 20 a of the impression cylinder 20. It has a diameter that occupies a position that protrudes more than this.

  In the position B, the clamp portion 2a is positioned at the position of the clamp portion 2a between the clamp portion 2a and the edge portion that is the boundary between the concave portion 21 and the cylindrical portion 22 by the medium diameter portion 8b. It is a position where a certain clamping force is generated. Therefore, if such a clamping force is generated, the clamp portion 2a may be on substantially the same surface as the circumferential surface 20a of the impression cylinder 20 in a state where the sheet feeding clamper 2 occupies the position B, or more than this. You may exist in the position protruded from the surrounding surface 20a.

  The large diameter portion 8c is formed continuously downstream of the medium diameter portion 8b in the rotation direction of the impression cylinder 20, and has a slightly larger diameter than the medium diameter portion 8b. As will be described later, when the clamper cam follower 5 passes through the large-diameter portion 8c, the roller 90 comes into contact with the plate cylinder 68 and pushes down the paper feed clamper 2, so that the clamper cam follower 5 is lifted from the paper clamper cam 8 at this time. Since the action of the direction is received, the large-diameter portion 8c only needs to have a diameter that occupies a position in contact with or separated from the clamper cam follower 5 in the state of receiving this action.

  The small-diameter portion 8d is continuously formed on the downstream side of the large-diameter portion 8c in the rotation direction of the impression cylinder 20, and the paper-feeding clamper 2 is discharged when the paper-feeding clamper 2 passes through the nip portion N. Is formed in such a manner that the diameter is gradually increased so that the opening is the largest when occupying the paper discharge position and the opening amount is gradually reduced.

  In addition, the sheet feeding clamper cam 8 has a uniform peripheral surface portion formed with the same diameter from the rotation center of the impression cylinder 20 at portions other than the small diameter portion 8a, the medium diameter portion 8b, the large diameter portion 8c, and the small diameter portion 8d. 8e is formed. The diameter of the paper clamper cam 8 means the distance from the rotation center of the impression cylinder 20.

  The roller 90 is a member for displacing the paper feed clamper 2 from the state B to the state C. Therefore, as shown in FIG. 3, the roller 90 is slightly higher from the peripheral surface 20a than the tip end portion of the paper supply clamper 2 that protrudes most from the peripheral surface 20a of the impression cylinder 20 in a state in which the paper supply clamper 2 is open. Specifically, it further protrudes from the circumferential surface 20a by a distance d. The roller 90 is freely rotatable, and its peripheral surface has a low coefficient of friction, high lubricity, and is smooth. Therefore, the roller 90 smoothly contacts the plate cylinder 68 and prevents the plate cylinder 68 from being deteriorated due to the contact.

  The timing at which the roller 90 displaces the sheet feeding clamper 2 from the state B to the state C is a member at the position facing the impression cylinder 20, that is, the plate cylinder, if the sheet feeding clamper 2 continues to occupy the state B. 68 or just before contacting the master 70. This timing is obtained as the timing when the roller 90 contacts the plate cylinder 20, and the displacement amount of the sheet feeding clamper 2 from the state B to the state C is also obtained by the distance d.

  Therefore, even if there are variations in manufacturing tolerances in the shapes of the sheet clamper 2, the clamper arm 4, the clamper cam follower 5 and the sheet clamper cam 8, the timing and displacement amount of the sheet clamper 2 are There is no variation between products. The distance d is set to 0.3 to 0.8 mm in the present embodiment, but this value is necessary and sufficient to ensure that the inventor has fed the sheet clamper 2 from the state B to the state C through experiments. And the timing is obtained as described above.

  In this embodiment, the second engaging portion with which the roller 90 engages is the plate cylinder 68. However, when the second engaging portion is the master 70, the distance d from the surface of the master 70 is the above-described distance d. The value of From the viewpoint of preventing the master 70 from being damaged, the plate cylinder 68 is more suitable for the second engaging portion than the master 70 as in the present embodiment. For this reason, the roller 90 is disposed at a position corresponding to a region further outside the region where the master 70 is wound around the plate cylinder 68.

  The master 70 is wound around the plate cylinder 68 so as to cover the opening of the porous support cylinder provided in the plate cylinder 68, and the second engaging portion is a non-opening portion of the plate cylinder 68. It is constituted by. Therefore, even if the roller 90 comes into contact with the plate cylinder 68, the roller 90 does not press the opening of the plate cylinder 68, so that the printing pressure is not applied to the opening and ink leakage is prevented. Is done.

  Further, in this embodiment, as shown in FIG. 5, the rollers 90 are provided at respective end portions in the width direction of the sheet feeding clamper 2, that is, in the left-right direction in FIG. 5. In other words, the second engaging portion is provided at a position corresponding to both end portions in the width direction of the sheet feeding clamper 2. Therefore, for example, the occurrence of stress in the direction of twisting the paper feed clamper 2 that occurs when the roller 90 is disposed only at one end of the paper feed clamper 2 is prevented. Clamp is realized.

  As shown in FIG. 4, the levitation mechanism 27 is capable of rotating a predetermined angle to the discharge claw 10 as a levitation member that levitates the leading end of the printing paper P from the peripheral surface 20 a of the impression cylinder 20 and the clamper base 6. The raised claw shaft 11 supported on the raised claw arm 12, the raised claw arm 12 fixed to the raised claw shaft 11, and the shaft 12a fixed to one end of the raised claw arm 12 are rotatably supported. The raised claw cam follower 13, the base end portion thereof is fixed to the raised claw shaft 11, and the free end portion thereof is fixed at a fixed position to the raised claw drive guide 14 that can be brought into contact with the discharge raised claw 10. The raised claw cam 17 shown in FIG. 8 (a) to which the raised claw cam follower 13 can be engaged and the urging means for urging the discharged paper raised claw 10 in the direction of drawing it into the recess 21 are not shown. With tension spring To have.

  The paper discharge raised claw 10 is made of a thin stainless steel plate having a thickness of 0.8 to 1.0 mm, and has a L-shaped cross section as shown in FIG. A plurality of notches (not shown) are formed at the front end of the paper discharge raising claw 10 in order to avoid interference with the stopper portion 2b of the paper supply clamper 2 and the paper discharge claw 44 during movement. As shown in FIG. 2 and FIG. 8, when the paper discharge lifting claw 10 is discharged, the leading edge of the paper discharge claw 10 moves to the outside of the recess 21 and the paper clamper 2 occupies the open position D. It occupies the paper floating position where the leading end of P is lifted and floated.

  The lifting claw cam 17 is integrally formed of a suitable synthetic resin or metal, and is fixed between the impression cylinder 20 and the sheet feeding clamper cam 8 by a side plate (not shown) on the main body 67 side. Yes. The lifting claw cam 17 has a configuration and function as a floating member cam for converting the rotational movement of the impression cylinder 20 in the counterclockwise direction into the floating operation of the paper discharge lifting claw 10 and transmitting it at a predetermined timing. Have. The raised claw cam 17 is formed with a cam shape for driving the discharged paper raising claw 10 only at the time of paper discharge.

  Specifically, as shown in FIGS. 2 and 8A, the lift-up claw cam 17 is engaged with the lift-up claw cam follower 13 provided on the discharge lift-up claw 10 side only at the time of paper discharge. In addition, there is a mountain-shaped large-diameter convex portion 17a for controlling so that the leading end portion of the printing paper P is lifted and floated in a state where the paper feeding clamper 2 is in the open position D when discharging. is doing. The large-diameter convex portion 17 a is formed at a position corresponding to the small-diameter portion 8 d of the paper clamper cam 8.

  As shown in FIG. 4 (a), the free end portion of the raised claw drive guide 14 can be in contact with the bottom surface of the clamper base 6 via a shaft 14a, as shown in FIG. 8 (b). A roller 14b that can be engaged with the paper discharge raising claw 10 is rotatably supported. Although one of the raised claw drive guides 14 is shown in FIG. 4 and the like, a plurality of raised claw drive guides 14 are fixedly attached to the raised claw shaft 11 with the same posture.

  The tension spring urges the paper discharge raising claw 10 from a floating position to a direction that occupies a non-floating position that is recessed inside the outer peripheral surface of the plate cylinder 20. Since the discharge claw 10 is urged toward the claw drive guide 14 by the urging force of the tension spring, the free end of the claw drive guide 14, specifically, the roller 14 b is The rotational driving force transmitted from the raising claw cam follower 13 to the raising claw shaft 11 always engages with the paper ejection lifting claw 10 and operates to move the whole paper ejection raising claw 10. This operation is smoothly performed without being interrupted by the clamper base 6 because the roller 14b is rotatable.

  The locking member driving means for driving the paper feed clamper 2 has a main motor 29, a drive system for the impression cylinder 20, and a paper feed clamper cam 8. The floating member driving means for driving the paper discharge raising claw 10 includes a main motor 29, a driving system for the impression cylinder 20, and a raising claw cam 17.

  Since the opening / closing mechanism 19 and the floating mechanism 27 provided in the sheet holding device 1 are configured as described above, when the impression cylinder 20 rotates counterclockwise in FIG. 2, the opening / closing mechanism 19 and the floating mechanism are accordingly accompanied. 27 also rotates counterclockwise in FIG. When the clamper cam follower 5 is engaged with the uniform peripheral surface portion 8e of the sheet feeding clamper cam 8, the sheet feeding clamper 2 is in a state where the leading end portion of the sheet P is not clamped. At this time, since the raised claw cam follower 13 of the impression cylinder 20 is not engaged with the raised claw cam 17, the raised claw drive guides 14 and the raised claw cam followers 13 are moved by the urging force of the tension spring. Each is held in the same state as shown in FIGS. 4 (a) and 4 (b), and the paper discharge raising claw 10 occupies the non-sheet floating position by the urging force of the tension spring.

When the impression cylinder 20 further rotates counterclockwise in FIG. 2 and the printing paper P is fed from the registration roller pair 83, the clamper cam follower 5 of the impression cylinder 20 is fed in accordance with the timing at the time of feeding. By engaging with the small-diameter portion 8a of the paper clamper cam 8, the clamper shaft 3 is rotated in the counterclockwise direction together with the clamper arm 4, whereby the paper feed clamper 2 is shown in FIGS. Thus, it occupies the position A, in other words, the paper feed opening position. When the printing paper P is further conveyed by the registration roller pair 83, the leading edge of the printing paper P moves toward the stopper portion 2b of the paper feeding clamper 2 that occupies the paper feeding release position, as shown in FIG. As shown, it abuts against the stopper portion 2b .

  When the impression cylinder 20 further rotates counterclockwise and the clamper cam follower 5 passes through the small diameter portion 8a of the paper clamper cam 8, the clamper arm 4 and the clamper shaft 3 are attached to the torsion spring 7 in this process. When the clamper cam follower 5 reaches the middle diameter portion 8b of the sheet feeding clamper cam 8 when the clamper cam follower 5 gradually decreases in the clockwise direction against the force and the opening amount of the sheet feeding clamper 2 gradually decreases. As shown in FIG. 3, the sheet clamper 2 is in a state B in which the leading end of the printing paper P is pressed between the edge portion which is a boundary portion between the concave portion 21 and the cylindrical portion 22 by the clamp portion 2a. Occupy.

In this state, the printing paper P is prevented from being detached from between the clamp portion 2a and the edge portion. Further, the printing paper P is prevented from being lifted and bent from the peripheral surface 20a of the impression cylinder 20.
The state B is maintained until the timing immediately before the paper feed clamper 2 contacts the plate cylinder 68 and the master 70 if the paper feed clamper 2 continues to occupy the state B. That is, the phenomenon in which the paper P is lifted from the peripheral surface 20a of the impression cylinder 20 and bends does not occur until such timing. Therefore, the image generated when the printing paper P contacts the master 70 before reaching the nip portion N. It is possible to prevent problems such as an abnormal image such as a double image and an abnormal image referred to as grain due to damage of the master 70 caused by contact with the printing paper P.

  When the impression cylinder 20 further rotates counterclockwise and the clamper cam follower 5 passes through the large-diameter portion 8c of the paper clamper cam 8, as shown in FIGS. 2 and 3, that is, the paper clamper 2 is in the nip. When passing through the portion N, the roller 90 comes into contact with the peripheral surface of the plate cylinder 68, and the clamper arm 4 and the clamper shaft 3 are rotated in the clockwise direction against the biasing force of the torsion spring 7. 2, the whole sinks from the peripheral surface 20a of the impression cylinder 20 and occupies the state C stored in the recess 21 as shown in FIGS.

  This prevents the paper feed clamper 2 from coming into contact with the plate cylinder 68 and the master 70, prevents damage to the paper feed clamper 2, plate cylinder 68, and master 70, and prevents abnormal images due to damage to the master 70. The The timing at which the roller 90 displaces the sheet feeding clamper 2 from the state B to the state C is obtained as the timing at which the roller 90 contacts the plate cylinder 68. Since the amount of displacement is also obtained by the distance d, there is no variation for each product in the timing and amount of displacement of the sheet feeding clamper 2. In the state C, as shown in FIG. 7, the leading end portion of the printing paper P is sandwiched between the clamp portion 2a and the paper receiving surface 6a.

  In this state, the printing portion P is lifted from the peripheral surface 20a of the impression cylinder 20 and bent, with the clamp portion 2a as a force point and the edge portion which is a boundary portion between the concave portion 21 and the cylindrical portion 22 as a fulcrum. If the sheet feeding clamper 2 continues to occupy the position B, the timing to receive such an action is the timing immediately before the sheet feeding clamper 2 contacts the plate cylinder 68 or the master 70. This timing is as described above. Since the time for forming the deflection is very small because it is strictly determined, the printing paper P has to be bent before the bending as shown by the solid line or before the bending becomes large as shown by the broken line. The nip portion N is entered.

  Therefore, problems such as abnormal images such as image doubles and abnormal images due to damage of the master 70 due to contact with the printing paper P do not occur. Even if the deflection occurs, the timing and amount at which the sheet feeding clamper 2 is displaced from the state B to the state C is strictly determined as described above, so that such a problem does not occur. Furthermore, as described above, a product in which such a problem is noticeable does not occur.

  The impression cylinder 20 continues to rotate counterclockwise while the sheet feeding clamper 2 occupies the position C and the printing paper P is held on the outer peripheral surface of the impression cylinder 20. The outer peripheral surface 20 a of the impression cylinder 20 presses the printing paper P conveyed to the nip portion N against the master 70 that has been made on the outer periphery of the plate cylinder 68. When the printing paper P is continuously pressed against the master 70 by the pressing of the impression cylinder 20, the master 70 is brought into close contact with the outer peripheral surface of the plate cylinder 68, and the punched portion of the master 70 is opened from the opening portion of the plate cylinder 68. The ink oozes out and is transferred to the surface of the printing paper P, and stencil printing is performed.

  When the impression cylinder 20 further rotates in the counterclockwise direction, and the sheet feeding clamper 2 occupying the position C also rotates in the counterclockwise direction, the roller 90 is separated from the plate cylinder 68, and then the sheet feeding clamper 2 is As shown in FIG. 2, the clamper cam follower 5 of the impression cylinder 20 engages with the small diameter portion 8 d of the paper clamper cam 8 to reach the vicinity of the paper discharge position before the paper discharge claw 44. The clamper shaft 3 is rotated counterclockwise by the urging force of the torsion spring 7, so that the paper feed clamper 2 occupies the state D, in other words, the paper discharge opening position as shown in FIGS.

  Further, at this time, the raised claw cam follower 13 of the impression cylinder 20 starts to engage with the raised claw cam 17, whereby the raised claw arm 12 and the raised claw as shown in FIGS. The shaft 11 rotates counterclockwise against the urging force of the tension spring, whereby the free end of each lifting pawl drive guide 14 swings counterclockwise, and the roller 14b is ejected. The raising claw 10 is pressed. In this way, the leading end of the paper discharge raising claw 10 passes through the stopper portion 2b, and the paper discharge lifting claw 10 occupies the paper floating position.

  In this way, the paper feed clamper 2 and the paper discharge raising claw 10 operate substantially simultaneously during paper discharge, and the free end of the paper supply clamper 2 is opened at the time of paper discharge. The paper floating position is higher than the position where the leading edge of the printing paper P floats, so that it is difficult for the paper to roll up, and the leading edge of the printing paper P is detached from the paper discharge lifting claw 10 during the floating and lifting operations. Therefore, the leading edge of the printing paper P is reliably lifted, discharged toward the paper discharge claw 44, and delivered, so that no jam or the like occurs. The printed printing paper P whose leading end has started to be guided by the paper discharge claw 44 is conveyed while being guided by the paper discharge claw 44 so as to be pushed by further rotation of the impression cylinder 20.

  A series of printing operations of the entire stencil printing apparatus 100 will be described. First, in order to make the heat-sensitive stencil sheet 70 a, an unmade heat-sensitive stencil sheet 70 a is passed between the platen roller 77 and the thermal head 78 and between the roller pair 79. When the plate making process is executed, the platen roller 77 and the roller pair 79 are driven, and at the same time, the document is read by the image scanner 61, and the thermal head 78 is based on the image data of the document subjected to the necessary image processing in the image processing unit. A voltage is applied to the specific resistance heating element, and plate-making is performed on the heat-sensitive stencil sheet 70a.

  The master 70 that has been made in this way is sent out toward the plate cylinder 68 by the roller pair 79, and in synchronization with this operation, the plate cylinder 68 waits at a position where the clamp 73 receives the master 70 that has been made. Then, the tip of the master 70 that has been made is made by the clamp 73. Therefore, the plate-making master 70 is wound around the plate cylinder 68 by rotating the plate cylinder 68 clockwise in FIG.

  Thereafter, the printing process is executed. The uppermost printing paper P on the paper feed table 81 is fed by the paper feeding roller 82, the registration roller pair 83 is driven in synchronization with the rotation of the plate cylinder 68, and the leading end of the printing paper P is in contact with the plate cylinder 68 and the impression cylinder. When the printing paper P is pressed against the master 70 on the plate cylinder 68 with the impression cylinder 20 displaced upward when it passes between the ink and the ink, the ink in the plate cylinder 68 oozes out from the perforated portion of the master 70. It is transferred to the printing paper P and printing is performed. At this time, the operation of the opening / closing mechanism 19 provided in the sheet holding device 1 prevents the occurrence of an abnormal image as described above. The printed printing paper P is satisfactorily peeled from the impression cylinder 20 by the floating mechanism 27 provided in the paper holding apparatus 1, and is guided to the paper conveyance device 84 by the paper discharge claw 44 by the rotation of the impression cylinder 20. The paper is discharged from the apparatus 84 onto the paper discharge tray 85 and stacked.

  The embodiment in which the second engaging portion is the plate cylinder 68 has been described above, but the second engaging portion can be configured by a cam shape formed on the sheet feeding clamper cam 8. This case is shown in FIG. 9, and different parts from the above embodiment will be mainly described. Constituent elements similar to those of the above-described embodiment are referred to with the same reference numerals, and description thereof will be omitted as appropriate.

When the paper clamper 2 passes through the nip portion N when the printing paper is locked between the medium diameter portion 8b and the small diameter portion 8d as the second engaging portion. A large-diameter portion 8f for controlling the clamper cam follower 5 to be engaged and the sheet-feeding clamper 2 to occupy the position C is formed.
The opening / closing mechanism 19 does not include the roller 90 and the shaft 4b, so that the clamper arm 4 is smaller than the above-described form.

  The large diameter portion 8c is formed continuously on the downstream side of the medium diameter portion 8b and the upstream side of the small diameter portion 8d in the rotation direction of the impression cylinder 20, and has a larger diameter than the medium diameter portion 8b. It arrange | positions in the aspect which forms a level | step difference with respect to 8b. Unlike the above embodiment, when the clamper cam follower 5 passes through the large diameter portion 8f, the clamper cam follower 5 always engages with the large diameter portion 8f. The diameter of the large-diameter portion 8f is large enough to sink the entire sheet feeding clamper 2 from the peripheral surface 20a of the impression cylinder 20.

  The timing of displacing the large-diameter portion 8f and the sheet feeding clamper 2 from the state B to the state C is a member or plate at a position facing the impression cylinder 20 if the sheet feeding clamper 2 continues to occupy the state B. It is immediately before contacting the barrel 68 or the master 70. This timing is obtained as the timing when the clamper cam follower 5 comes into contact with the large diameter portion 8f, and the displacement amount of the sheet feeding clamper 2 from the state B to the state C is also the medium diameter portion 8b and the large diameter portion 8f. It is obtained by the difference in diameter. This difference in diameter was obtained by the inventor as a result of an experiment in which the sheet feeding clamper 2 is reliably displaced from the state B to the state C by a necessary and sufficient amount.

  Therefore, in the sheet holding device 1 having such an opening / closing mechanism 19, the impression cylinder 20 further rotates counterclockwise from the state in which the sheet feeding clamper 2 occupies the position B, as shown in FIG. When the clamper cam follower 5 passes the large-diameter portion 8f of the sheet-feeding clamper cam 8, that is, when the sheet-feeding clamper 2 passes the nip portion N, the large-diameter portion 8f moves the clamper arm 4 and the clamper shaft 3 to each other. By rotating clockwise against the urging force of the torsion spring 7, the entire sheet feeding clamper 2 sinks from the peripheral surface 20 a of the impression cylinder 20 and occupies the state C stored in the recess 21.

  This prevents the paper feed clamper 2 from coming into contact with the plate cylinder 68 and the master 70, prevents damage to the paper feed clamper 2, plate cylinder 68, and master 70, and an abnormality called graininess due to damage to the master 70. Images are prevented. The timing at which the sheet feed clamper 2 is displaced from the position B to the position C is obtained as the timing at which the clamper cam follower 5 rides on the large-diameter portion 8f, and the sheet clamper 2 from the position B to the position C The amount of displacement is obtained by the difference in diameter between the medium diameter portion 8b and the large diameter portion 8f, that is, the size of the step formed by the medium diameter portion 8b and the large diameter portion 8f.

  In the state C, the leading end portion of the printing paper P is sandwiched between the clamp portion 2a and the paper receiving surface 6a. In this state, the clamp portion 2a is a power point, and is a boundary portion between the concave portion 21 and the cylindrical portion 22. With the edge portion as a fulcrum, the printing paper P is lifted from the peripheral surface 20a of the impression cylinder 20 and is subjected to a bending action. If such a feeding action is assumed, the sheet feeding clamper 2 continues to occupy the position B. For example, the timing immediately before the sheet feeding clamper 2 comes into contact with the plate cylinder 68 or the master 70 is set as described above. Therefore, the time for forming the deflection is very small. Before such deflection becomes large, the nip portion N is entered, and there are no problems such as an abnormal image such as grain or an abnormal image caused by damage to the master 70 due to contact with the printing paper P. Further, since the amount of deflection to be formed is determined by the size of the step formed by the medium diameter portion 8b and the large diameter portion 8f, such a problem does not occur.

  The operation for printing on the printing paper P performed when the paper feed clamper 2 occupies the position C by the impression cylinder 20 is the same as that described above, and the master 70 is in close contact with the outer peripheral surface of the plate cylinder 68. At the same time, ink oozes out from the holed portion of the plate cylinder 68 to the holed portion of the master 70 and is transferred to the surface of the printing paper P, and stencil printing is performed.

  It should be noted that the accuracy with respect to the timing and amount at which the sheet feeding clamper 2 is displaced from the position B to the position C is determined from the member at the position facing the impression cylinder 20 as in the above embodiment. It is more expensive to have the sheet clamper 2 driven. This is because the positioning accuracy between the impression cylinder 20 and the plate cylinder 68 and the positioning error between the sheet feeding clamper 2 and the roller 90 are more accurate, such as the members such as the clamper arm 4 that supports the sheet feeding clamper 2 and the sheet feeding. This is because it is higher than the accuracy of the positioning error caused by the variation in manufacturing shape of the members such as the sheet feeding clamper cam 8 for displacing the clamper 2 and the accumulation of these variations.

  As described above, the sheet holding device 1 and the stencil printing apparatus 100 having the sheet holding device 1 have been described as embodiments for carrying out the present invention. However, the second engaging portion is a member located at a position facing the impression cylinder such as a plate cylinder. In the case of constituting by the above, the member applied to such a member is not limited to the rotating body such as the roller 90 in the above-mentioned form from the viewpoint of preventing the deterioration of the member facing the impression cylinder, and for example, a friction coefficient such as an arm. It is possible to smoothly engage a member located at a position facing the impression cylinder, such as a low-cost member or a highly-lubricated member, so that deterioration of the member can be prevented.

  In addition, the member engaged with the first engagement portion, the second engagement portion, and the third engagement portion may be a member integrated with the locking member, a member having a low coefficient of friction, or lubrication. If the member can be smoothly engaged with a member located at a position facing the impression cylinder, such as a high-performance member, and the deterioration of the member can be prevented, the locking member itself can be used.

  In each of the above-described embodiments, the second locking state has been described as a state in which the entire locking member is sunk from the peripheral surface of the impression cylinder. However, as long as there is no problem due to collision with the plate cylinder or the like. It can also be a position substantially equal to the peripheral surface. The substantially equal position is a range in which it is difficult to mechanically be completely the same as the peripheral surface, and a range in which a defect due to a collision with the plate cylinder does not substantially occur. If it is.

  The present invention can be applied not only to stencil printing apparatuses but also to other types of printing apparatuses. In the case where there are a plurality of impression cylinders mounted on the printing apparatus, the sheet holding device can be arranged corresponding to each impression cylinder, and in such a case, the sheet holding apparatus is A plurality of printing apparatuses can be mounted on one printing apparatus.

1 is a front view showing an outline of a printing apparatus to which the present invention is applied. FIG. 2 is a front view illustrating a sheet holding device mounted on the printing apparatus illustrated in FIG. 1, a locking member provided in the paper holding device, and a locking member displacement unit. FIG. 3 is an enlarged front view of the locking member displacing means shown in FIG. 2. It is the front view which expanded and showed the state and the locking member displacement means which the locking member showed to the open state shown in FIG. It is the top view which expanded and showed a part of locking member displacement means shown in FIG. It is the front view which expanded and showed the state which the locking member occupied the 1st locking state position. It is the front view which expanded and showed the state which the latching member shown in FIG. 2 occupied the 2nd latching state position. It is the front view which expanded and showed the state which the latching member shown in FIG. 2 occupied the other open state. It is a front view which shows the outline of the paper holding | maintenance apparatus of another form, and the latching member displacement means with which this was equipped.

Explanation of symbols

2 engaging member 2a engaging portion 8a third engaging portion 8b first engaging portion 8f second engaging portion constituted by a member occupying a fixed position 19 engaging member displacing means 20 impression cylinder 20a impression cylinder The peripheral surface 68 of the plate cylinder 68, 70 as the second engaging portion 90 The member at the position facing the impression cylinder 90 The member integral with the locking member 100 Printing apparatus A Open position B First locking position C Second locking position P paper

Claims (11)

A locking member that moves together with the impression cylinder, and has a locking portion for locking the leading end of the paper with the impression cylinder;
As a locking state for locking the leading end of the sheet to the locking member, the position where the locking portion protrudes from the position on the substantially circumferential surface of the pressure drum or this position. A locking member displacing means for providing a first locking position occupied and a second locking position where the entirety of the locking member is substantially equal to the circumferential surface of the impression cylinder or submerged from the circumferential surface; Yes, and
A first engaging portion for engaging the locking member displacement means with the locking member itself or a member integral with the locking member, and for bringing the locking member into a first locking state; , sheet holding device for perforated and a second engagement portion for the engaging member to the second locking condition position.   2. The sheet holding device according to claim 1, wherein the locking member displacement means displaces the locking member from the first locking state to the second locking state. The sheet holding device according to claim 1, wherein the locking member is immediately before engaging with a member at a position opposite to the impression cylinder. 3. The impression cylinder according to claim 1, wherein the second engaging portion engages with the locking member if the locking member continues to occupy the first locking position. A sheet holding device comprising a member at a position opposite to the sheet. 4. The paper holding apparatus according to claim 3, wherein the member located at a position facing the impression cylinder is a plate cylinder . 5. The paper holding device according to claim 4, wherein the second engaging portion is constituted by a non-opening portion of the plate cylinder . 3. The paper holding device according to claim 1 , wherein the second engaging portion is constituted by a member occupying a fixed position . The paper holding apparatus according to any one of claims 1 to 6, the first engaging portion, the sheet holding device, characterized in that constituted by a member occupying a fixed position. 8. The paper holding device according to claim 1 , wherein the second engaging portion is provided at a position corresponding to both end portions in the width direction of the locking member. . 9. The paper holding device according to claim 1, wherein the locking member displacing means receives the leading edge of the paper between the locking member and the impression cylinder. A sheet holding device characterized by providing an open position . 10. The sheet holding device according to claim 9, wherein the locking member displacing means is engaged with the locking member itself or a member integral with the locking member to bring the locking member into the open position. A sheet holding device having a third engaging portion .   An impression cylinder for locking the leading end of the sheet between the sheet holding device according to any one of claims 1 to 10 and the locking portion of the locking member provided in the sheet holding device. And a printing cylinder arranged opposite to the impression cylinder.

Images