Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F27/00—Devices for attaching printing elements or formes to supports
  • B41F27/10—Devices for attaching printing elements or formes to supports for attaching non-deformable curved printing formes to forme cylinders
  • B41F27/105—Devices for attaching printing elements or formes to supports for attaching non-deformable curved printing formes to forme cylinders for attaching cylindrical printing formes

Definitions

• the present invention relates to a printing machine and more particularly to a device intended to ensure the fixing and positioning of a removable printing sleeve on a support axis of such a machine.
• the plate cylinders of printing machines usually consist of a cylindrical or conical shaft, on which is fixed a sleeve carrying, on its external peripheral part, the engraving intended to carry out the printing.
• a sleeve carrying, on its external peripheral part, the engraving intended to carry out the printing We also know that it is important, on such machines, that the user is able to quickly and easily replace one sleeve with another.
• the deformation of the sleeve is usually obtained by blowing pressurized air between the internal surface of the latter and the external surface of the shaft, through small diameter holes provided in the latter.
• the object of the present invention is to propose means making it possible to precisely angularly position the printing forms of a printing machine or a blanket sleeve when the latter is not continuous and includes an interruption.
• the present invention thus relates to a device for fixing a printing sleeve, in particular a printing form or a blanket sleeve on a cylindrical drive shaft in which a deformable sheath is disposed between the sleeve and the shaft, the surface of the shaft being hollowed out with a series of cavities separated by holding surfaces on which the sheath is supported, the device comprising means capable of ensuring deformation in the radial direction, deformable zones of the sheath under the effect of an overpressure on the external face thereof or a depression on its internal face, characterized in that the shaft and the sleeve are provided with angular indexing means.
• These angular indexing means may consist of a finger disposed on one of the two parts to be indexed and which is capable of being positioned in a cavity, of complementary shape, in the other part.
• This finger can be mounted mobile in a housing and positioned in said cavity under the action of elastic means such as for example a compression spring.
• the sleeve will be covered with a removable thin tube indexed relative to the latter and the separation surface between the internal surface of the tube and the external surface of the sleeve will be in communication with controlled means for supplying air under pressure.
• This separation surface can be connected by at least one conduit with the controlled supply of pressurized air to the separation surface existing between the sleeve and the sleeve.
• each supply duct for controlled air under pressure of the separation surface existing between the sleeve and the sleeve will be provided with a control valve making it possible to send the pressurized air flow either to this last separation surface, when it is desired to remove the sleeve, or to the separation surface of the sleeve and the tube when it is desired to remove the latter.
• control valve will be of the rotary type and the angular indexing means will consist of a finger integral with this valve so that this finger is in engagement with the sleeve when the valve is positioned to send the air flow under pressure towards the tube.
• valve may include a finger capable, in a given position, of blocking the axial movement of the sleeve.
• Figure 1 is a partial view in longitudinal cross section of a device according to the invention.
• FIG. 2 is a partial side view of the device shown in FIG. 1.
• Figure 3 is a partial view in longitudinal cross section of an alternative embodiment of the device according to the invention.
• FIG. 3a is a partial enlarged view of a shutter valve usable in the embodiment of the present invention shown in FIG. 3.
• Figure 3b is a detail view of a valve control member used in the embodiment of Figures 4 and 4a.
• Figure 4 is a partial view . in longitudinal cross section of another alternative embodiment of the device according to the invention, the shutter valve being tilted in a first position.
• Figure 4a is a partial view of the embodiment of the invention shown in Figure 4, the shutter valve being tilted in a second position.
• FIG. 1 shows an interchangeable printing cylinder according to the invention which may also be, in the case of offset printing, a plate or blanket cylinder, in the case of flexographic printing a plate cylinder, or in the case of gravure printing an engraved cylinder and counterpart.
• the device according to the invention consists of a cylindrical shaft 1 with a longitudinal axis xx 'which is intended to support and drive a sleeve 3.
• the shaft 1 has, at each of its ends, ' 5.5 dolls' intended to ensure its maintenance and rotation training.
• the shaft 1 is hollowed out, on its periphery, three annular cavities 7, which are each in communication, by a radial duct 9, with a longitudinal channel 11 which opens at one end of the shaft 1, the cavities 7 being separated by cylindrical uncut holding surfaces 12.
• a sheath 2 of small thickness is fitted onto the holding surfaces 12 of the shaft 1. This sheath is made of epoxy resin reinforced with glass fibers.
• the shaft 1 is hollowed out with a second axial and longitudinal channel 13 which also opens at one end of the shaft 1 and which is in communication with five radial conduits 15 (only one of which is shown in the drawing).
• the sleeve 2 is pierced, opposite each conduit 15, with an orifice 18.
• the shaft 1 is hollowed out by two circular grooves in which are arranged O-rings 21.
• Another seal O-ring 21 ′ is arranged in a circular groove at the other end of the shaft 1.
• the sleeve 3 consists in particular of a metal, for example aluminum. It can also be made of synthetic materials using a structure in particular honeycomb, so as to have a high rigidity.
• This shoulder is pierced with a cylindrical cavity of axis yy 'parallel to the axis xx' of the shaft 1 and which opens to the outside through a hole of smaller diameter.
• the cavity receives a cylindrical finger 25 and the hole receives the guide shank 27 thereof.
• a compression spring 29 biases the finger 25 outwards and the latter is retained in its cavity by holding means (of the circlip type) provided on the guide tail 27.
• the sleeve 3 is provided with a slot radial 31 (possibly made with a milling cutter) and whose width corresponds to the diameter of the finger 25, so that in the operating position, it penetrates into said slot and thus ensures an angular indexing of the sleeve 3 relative to the shaft 1.
• the indexing finger 25 also has another advantage. Indeed, when we change format and move to a large diameter sleeve, the friction existing between the shaft 1 and the sleeve 3 may not be enough to transmit the torque necessary for the rotary drive. of the sleeve, in particular in offset for the plate and blanket cylinders. In such a situation, the finger 25 then participates in the transmission of part of the torque, and it will be possible to call on it even when no indexing function proves necessary, as it is when one uses a continuous blanket.
• the sleeve 3 receives a plate 33, the external face of which constitutes the active surface of the cylinder and which is fixed thereon by embedding its two ends 33a and 33b in a longitudinal slot. 35 hollowed out in the sleeve 3, as shown in FIG. 2.
• the external plate can of course be made differently and be formed for example of a thin tube 37 whose external surface constitutes the active part.
• the assembly and disassembly of this tube 37 will be carried out by creating an air pressure between its internal surface and the external surface of the sleeve 3.
• the same air supply ducts and orifices 13 can be used as those used for disassembly / reassembly of the sleeve 3, and of the radial ducts 14 (only one of which is shown in the drawings) bring the pressurized air between the internal surface of the tube 37 and the external surface of the sleeve 3.
• a stop has been provided. removable retainer 39 which prevents any sliding of the sleeve on the shaft 1 during this operation.
• This holding function can also be fulfilled by the indexing finger which will then be placed on the side opposite to the shoulder 20 on the side from which the sleeve 3 is extracted.
• this valve can consist of a ball 42 which is applied against a valve seat 43 by a compression spring 45.
• the valve seat 43 is such that, when the tube 37 is in place on the sleeve 3, the ball 42 is slightly repelled by the latter so that a space is formed between the ball and the valve seat 43 thus leaving the passage for air under pressure, while, when the tube 37 is not in position on the sleeve 3, the spring 45 and the pressurized air push the ball 42 against the valve seat 43 and then closes the latter.
• valve 41 for directing the flow of pressurized air from the lines 15 is between the sleeve 3 and the sleeve 2 (disassembly / reassembly of the sleeve 3), or between the tube 37 and the sleeve 3 (disassembly / reassembly of the tube 37).
• the control member of this valve 41 can be constituted by an element 47 in the form of a half-moon whose position of the rounded part 51 determines the immobilization or the axial release of the sleeve 3.
• the rounded part 51 when, as shown in FIGS. 3b and 4, the rounded part 51 is in the high position, it axially blocks the sleeve 3 (which corresponds to a position of the valve 41 allowing the pressurized air flow to be brought between the tube 37 and the sleeve 3 so as to allow the withdrawal of the tube 37).
• FIG. 3b the control member of this valve 41 can be constituted by an element 47 in the form of a half-moon whose position of the rounded part 51 determines the immobilization or the axial release of the sleeve 3.

Landscapes

• Supply, Installation And Extraction Of Printed Sheets Or Plates (AREA)
• Rotary Presses (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=30129655

Family Applications (1)

Country Status (5)

Families Citing this family (9)

Family Cites Families (7)

• 2002
  • 2002-08-02 FR FR0209879A patent/FR2843071B1/fr not_active Expired - Fee Related
• 2003
  • 2003-07-31 US US10/523,026 patent/US20050257706A1/en not_active Abandoned
  • 2003-07-31 EP EP03769525A patent/EP1525096A2/de not_active Withdrawn
  • 2003-07-31 WO PCT/FR2003/002427 patent/WO2004014653A2/fr not_active Application Discontinuation
  • 2003-07-31 JP JP2004526961A patent/JP2005534546A/ja active Pending

Non-Patent Citations (1)

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