Abstract:
Deformable hollow bodies are placed in cylinders of printing presses to actuate retaining and clamping devices. The hollow bodies require a sealed supply channel for supply of a pressure medium. A sealing surface and a dividing surface between the cylinder and the hollow body are arranged parallel to each other and generally perpendicularly to the direction of pressure generated by the pressure medium flowing into the hollow body.

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a method and to a device for supplying a pressure medium to a deformable hollow body. The hollow body is provided with an opening that receives a supply of the pressure medium. 
     BACKGROUND OF THE INVENTION 
     An arrangement of a hose, which can be used for operating a device for clamping flexible printing plates on a forme cylinder and which can be charged with a pressure medium, is known from EP 0 606 604 B1. The hose is arranged on a fastening strip, fixed in place on the cylinder, in the axial extension approximately in the middle between two axial, prestressed clamping strips that are extending in an axis-parallel groove. 
     The supply of pressure medium to the hose is accomplished through a connecting tube. The connecting tube extends through the fastening strip and is frictionally connected with a sleeve on the underside of the fastening strip facing away from the hose. The sleeve is sealed with the aid of sealing rings and is connected with a flange arranged on the underside of the fastening strip. The sealing faces between the connecting tube and the sleeve, or between the sleeve and the flange, extend parallel in respect to the pressure and force direction. 
     The connecting tube, which is embodied as a threaded pin with a bore, projects, on the side facing the hose, through a hole in the casing of the hose into its interior. The connecting tube can be fastened releasably and interlockingly in the interior of the hose by the use of a nut. 
     When mounting the hose, the hole in the hose casing must be pushed on the connecting tube fixed on the cylinder and, if required, must be fastened on the inside of the hose with a nut. In the arrangement depicted in EP 0 606 604 B1, the mounting of the hose must be performed in the radial direction from the shell surface of the cylinder. 
     When a pressure medium is supplied to the hose through the connecting tube, the hose inflates or expands and pushes the two clamping strips apart in the circumferential direction of the forme cylinder. 
     EP 0 307 890 B1 shows a device for clamping and tensioning printing plates on a plate cylinder, by using hoses which can be charged with a pressure medium. For tensioning the printing plate, the entire tensioning and clamping device, which is movably arranged in the cylinder groove, is displaced approximately in the circumferential direction of the plate cylinder. This movement takes place against the force of a restoring spring by use of a hose, which can be charged with a pressure medium and which is supported on the groove wall fixed in the cylinder. The clamping device is operated by a toggle lever, which is maintained in the clamping position by a spring force. A hose is used for opening the clamping device which hose, when charged with a pressure medium, forces the toggle lever out of the extended position against the spring force. The mechanism used for the introduction of a pressure medium into the hose is not explained in this prior art document. 
     DE 33 09 815 C2 discloses a clamping device for a cylinder shell, wherein a clamping sleeve, together with the shell surface of a journal and O-rings arranged between the journal and the clamping sleeve, form a deformable annular chamber. The supply of a pressure medium takes place through a radial bore through the journal, with an orifice in the annular chamber. When charged with a pressure medium, the clamping sleeve is deformed in the radial direction of the journal and holds a front disk of a cylinder shell. 
     Additional examples of mechanisms and of devices for holding or clamping of plates or covers on cylinders, and which are operated by pressure media, are provided in the publications EP 0 606 604 A 1, EP 0638 420 A1, EP 0 713 770 B1, EP 0 740 609 B1 or EP 0 858 890 A1, and depict a lever mechanism, the drive mechanism for a toothed rack or leaf spring, a displaceable clamping jaw or the plate or covering for the cylinder itself, which is to be held. The above examples all require an assembly at the end, or laterally inside the channel, of the hose which can be charged with pressure medium in the cylinder. 
     A solution for supplying a medium charged with pressure to a rotatable body itself is proposed in the publication EP 0 554 815 A1, for example. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is directed to providing a method and a device for supplying a pressure medium to a deformable hollow body. 
     In accordance with the present invention, this object is attained by providing the deformable hollow body with a pressure medium receiving opening. The hollow body is arranged on a support surface with its opening aligned with a mouth of a pressure medium supply line. Charging of the hollow body with a pressure medium seals the opening in the hollow body to the supply line and to the support surface. The supply line does not penetrate the hollow body. 
     The advantages to be realized by the present invention reside, in particular, in that only slight demands are to be made on the accessibility of the supply device for the pressure medium and the position of the hose, since there is no rigid passage, fixed in the cylinder, and extending through the hose wall. The device in accordance with the present invention permits the arrangement of, and exchange of hoses to be supplied with pressure media, at places inside the cylinder, or inside the clamping device, which are difficult to reach. The supply device permits the employment of various types of hoses to be charged with pressure medium for operating holding or clamping devices. For example, the pressure medium hose can be inserted inside the channel into the clamping device in the circumferential direction laterally or at the front or end of the channel. 
     It is also an advantage of the device of the present invention that, in case of a relative movement between the hose and the line for supplying the pressure medium, no damages occur. This is because the parts of the supply line to be assigned to the cylinder and to the hose do not penetrate each other. 
     A further advantage of the device of the present invention for supplying pressure medium is the simple and rapid pre-assembly, as well as the insertion into the clamping device, without a requirement for a tool or aids which the invention provides. 
     The self-sealing property of the device of the present invention, because of the arrangement of the sealing faces perpendicularly to the pressure and force direction acting in the operating state, is particularly advantageous. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment of the present invention is represented in the drawings and will be described in greater detail in what follows. 
     Shown are in: 
     FIG. 1, a schematic side elevation view, partly in section of a portion of a hose, which hose can be charged with a pressure medium, and a supply device in accordance with the present invention, and in 
     FIG. 2, an enlarged representation of the passage of FIG.  1 . 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A device, not described in detail, and which is useable for the frictional or for the interconnected holding and/or clamping of at least one cover or dressing, for example a printing plate, on a forme cylinder, or a rubber blanket on a transfer cylinder, is arranged in a cylindrical body, such as, for example, a forme or transfer cylinder of a printing press, in an axially extending channel of a cylinder shell. 
     The actuation of that device, for clamping or holding the cover or dressing, takes place through the use of a deformable hollow body such as, for example, a hose  01 , which hose  01  is present in the channel of the cylinder and which hose  01  can be charged with a fluid which acts as the pressure medium to expand the hose. That pressure medium can be, for example, compressed air. 
     As may be seen by initially referring to FIG. 1, the hose  01  is arranged between a surface  02 , for example the support surface  02 , which support surface  02  is assigned to the cylinder, and a surface  03 , which is assigned to the device for clamping or holding to be operated by the hose  01 . For example, the support surface  02  is embodied as a lateral wall of the channel, fixed in the cylinder. In another embodiment, it can also be a surface of the movable device for holding or clamping. 
     On its side facing the support surface  02 , a wall  04  of the hose  01  has an opening  09 , through which the pressure medium is fed into the hose  01 . The hose opening  09  is aligned with, and cooperates with a mouth  08  of a line, which line mouth  08  is arranged in the side of the support surface  02  and facing the hose  01 . 
     The opening  09  in the hose  01  can be a cutout  06  formed directly in the wall  04  of hose  01 . However, opening  09  can also be a bore  09  in a fitting  07  which is arranged in the cutout  06  of the wall  04 . 
     In the preferred embodiment depicted in FIGS. 1 and 2, the opening  09  in the hose  01  is embodied as an axial bore formed in a disk  07  that is arranged in the cutout  06  of the hose  01 . The disk  07  is provided with a circumferential groove  11  in its exterior shell surface. The external circumferential groove  11  divides the disk  07  into a first or outer flange  12  facing the support surface  02 , a second flange  13  located in the interior of the hose  01 , and a constriction  14  located between them. On the outer end face of the first or outer flange  12  there is a surface  16  which, in cooperation with the support surface  02 , acts as a sealing face. On its side facing the hose  01  the outer flange  12  has an inner face formed by a surface  17 . This outer flange inner face  17  acts as a sealing face with the outer surface of the wall  04  of the hose  01 . 
     In an advantageous configuration of the disk  07 , the structure of the outer flange end face sealing surface  16  should not exceed a surface roughness of 16 μm, preferably 4 μm. The outer flange inner face surface  17  does not require such high demands on the surface structure, so that a surface roughness of 16 μm is sufficient. 
     An interior diameter d 09  of the bore  09  of the disk  07  is sized based on the required pressure medium flow and in the present embodiment d 09 =3 mm. The exterior diameter d 14  of the constriction  14 , for example, is d 14 =6 mm. The exterior diameter d 12 , for example d 12 =8.5 mm, of the outer flange  12  is a function of the demands made on the seal of the outer flange outer end face sealing surface  16  of the disk  07  toward the support surface  02 , and the outer flange inner face surface  17  of the disk  07  toward the wall  04  of the hose  01 . The second or inner flange  13  is used for holding the disk  07  in the wall  04  of the hose  01 , and in the preferred embodiment has an exterior diameter of d 13 =10 mm. The disk  07  has a height “h” of, for example, h 07 =3.5 mm. In the preferred embodiment, the outer flange  12  is embodied with a height h 12 =1 mm, and the constriction with a height h 14 =1.5 mm, which construction height h 14  depends on the thickness of the wall  04  of the hose  01 . In the preferred embodiment, the disk  07  has a radially extending groove  21  on the outer end face of the inner flange  13 . This groove  21  makes possible the supply of, or the escape, of the pressure medium through the bore  09  in case the wall  04  of the hose  01 , which is located directly opposite the inner flange  13 , rests directly on the inner flange  13 . 
     In place of the disk  07  described in the preferred embodiment, other constricted forms can be selected as the passage  07 , which have a structure, embodied as flange  12  in the preferred embodiment, cooperating with the support surface  02 , with a flat surface  16 ; a flat surface  17  cooperating with the wall  04  of hose  01 , if required; a detent, such as the inner flange  13  in the preferred embodiment, and arranged in the interior of the hose  01 : a taper, which is as constriction  14  in the preferred embodiment, and which projects at least partially into the wall  04 ; and a penetrating opening extending in the longitudinal direction, in the preferred embodiment, a bore  09 . The taper  14  can also be embodied as a tube which, when there is a detent  13 , connects the latter with the disk  12 . 
     On the side of the hose  01  facing the support surface  02 , the cutout  06 , in which the disk  07  is arranged, is located in the wall  04  of hose  01 . Advantageously the diameter d 06  of the cutout  06 , for example d 06 =5 mm has been selected, depending on the elastic properties of the hose material, to be less than the exterior diameter d 14  of the constriction  14 , so that an interconnected and frictionally tight connection between the disk  07  and the hose  01  is created. Several spaced disks  07  and associated mouths of lines  08  for hose  01  can be provided in the support surface  02 . For reasons of ease of assembly; the disk  07  and the associated mouth of the line  08  are preferably arranged in the area of the ends of the hose  01 . The disk  07  is positioned on the hose  01  in such a way that, with the hose  01  inserted into the channel of the cylinder, the longitudinal axis of the bore  09  of the disk  07 , and the longitudinal axis of the mouth of the line  08  cooperating with the disk  07  are fully aligned, in the ideal case. To be operational, the bore  09  and the mouth of the line  08  must at least intersect. 
     The hose  01 , equipped with a disk  07 , is arranged in the channel, and is fixed in relation to the support surface  02 , in such a way that the outer flange outer end face sealing surface  16  facing the support surface  02  rests on the support surface  02 , even in the relaxed state of the hose  01  when hose  01  is not charged with a pressure medium. 
     The interior diameter d 08  of the mouth of the line  08  can be equal to the interior diameter d 09  of the opening  09 , or bore  09 . To facilitate an assured intersection of the mouth of the line  08  and the opening  09 , the interior diameter d 08  of the mouth of the line  08 , for example d 08 =5 mm, can be selected to be greater than the diameter d 09  of the opening  09  in the disk  07 . This assures the certain coverage of the mouth of the line  08  by the flange  16 , even in the flaccid state where the hose  01  is not charged with a pressure medium, as well as in the case of manufacturing or assembly tolerances in the arrangement of the hose  01 , or of the disk  07 , or of the mouth of the line  08 . 
     A further increase of the interior diameter d 08  also requires an increase of the diameter of the cooperating outer flange  12 . When using a disk or other fitting  07 , the exterior diameter d 12  of the outer flange, the interior diameter d 09  of the bore  09  and the interior diameter d 08  of the mouth of the line  08  should be selected in an advantageous manner in such a way, that the relationship:            (     d12   -   d09     )     2          〈     d08                   〈       (     d12   +   d09     )     2                                  
     is met. 
     In further preferred embodiment of the present invention, which is not specifically represented, the diameter of the bore  09  of the disk  07  can also be selected to be larger than the interior diameter d 08  of the mouth of the line  08 . 
     In an advantageous manner, similar demands should also be made on the surface structure of the support surface  2 , at least in the area of the mouth of the line  08 , that are made on the surface  16 , namely a surface roughness of less than or equal to 16 μm. Alternatively to this, it is possible to arrange a sealing element  19 , such as for example a rubber or metal seal ring  19 , in a groove  18  surrounding the mouth of the line  08  in the support surface  02 . The sealing element  19  arranged in the support surface  02 , and the surface  16  of the outer flange  12  of the disk  07  facing it, in this case act together as sealing faces. 
     If, in an embodiment variation of the device of the present invention, the use of a disk  07 , or a fixture  07  of a different type, is omitted, the cutout  06  of the hose  01  constitutes the opening  09  for supplying the pressure medium to the hose  01 . In this case, the support surface  02 , or the sealing element  19  arranged in it, and an outer surface  22  of the wall  04  facing the support surface  02 , act together as a sealing face. 
     When the hose or hollow body  01  is charged with a pressure medium, the same pressure acts inside the hollow body  01  on all surfaces of body  01  in the normal direction. Here, the direction of the pressure P is understood to be the direction which is oriented approximately parallel with the longitudinal axis of the opening  09 . The above-described embodiments have in common the arrangement of sealing faces, which are essentially perpendicular, in respect to the direction of the pressure P, between the two units, which sealing faces are configured so they can be separated from each other, and therefore provide the self-sealing property of the device for supplying the pressure medium. When charged with pressure, the sealing faces are pressed against each other, so that in the operational state, the act of the charging of the hose  01  with pressure medium itself provides the seal of the supply device. 
     The support surface  02  to be assigned to the cylinder, and with the mouth of the line  08 , constitutes a first unit. The hollow body  01  with the opening  09  and with the surface  16 , or  22 , constitutes a second unit, acting together with the first unit, which first and second units are structured to be separable from each other. The seal of the supply device for the pressure medium between these two units, which can be separated from each other, takes place via the surfaces  16  or  22 , together with the support surface  02 , or the sealing element  19 . The separating and sealing faces are located on planes which, when the hollow body  01  is charged with pressure medium, extend almost perpendicularly in respect to the direction of the pressure P. Since the two units do not penetrate each other, in the state when pressure is applied, the connection between the two units takes place only in a frictionally connected manner, in all spatial directions. The hollow body  01  with the opening  09 , if required with the fixture  07  having the opening  09 , can, in this way, be inserted, or removed, in a simple manner, and can be separated from the support surface  02  to be assigned to the cylinder. A separation takes place in an advantageous manner almost perpendicularly in respect to the mouth of the line  08 , or of the opening  09 . 
     The mounting and mode of functioning of the device for supplying a pressure medium in accordance with the present invention are as described in what follows: 
     A cutout  06  is arranged in the hose  01  at the location in the hose  01  defined by the position of the mouth of the line  08  and the hose  01 . The disk  07  having the opening  09  is pushed, for example from the inside of the hose  01 , through the cutout  06 . The device for supplying the pressure medium, consisting of the hose  01  and the disk  07 , is inserted into an appropriate holder, not described in great detail here, in the channel of the cylinder. After the device for supplying the pressure medium has been inserted with the correct fit in respect to the position of the mouth of the line  08 , i.e. so that the mouth of the line  08  and the opening  09  in the fixture  07  at least partially intersect, the pressure supply device is ready to operate. Thereafter, the charging of the hollow body  01  with pressure medium takes place, and with this, the simultaneous sealing between the surfaces  02 ,  16 , or  22 , which are arranged to lie flat on each other and do not penetrate each other, namely the support face  02  and the surface  16 , or  22 , of the passage  07 , or of the hollow body  01 . 
     Upon actuating a device, which is not specifically represented here, for providing pressure medium, that pressure medium, which may be, for example, compressed air, flows through the mouth of the line  08  and the bore  09  of the disk  07  into the hose  01 . The previously flaccid hose  01  is filled and takes up more space. It is supported on the support surface  02  and contacts the surface  03  of the device for clamping or releasing, holding or letting go, of dressings or coverings on cylinders. Because of the resistance of the clamping or holding device which can result from the dressing or covering to be clamped itself, from a spatial limitation, or from the restoring force of the device, the wall  04  of the hose  01 , and therefore also the outer flange  12 , are pressed against the support surface  02 , and the outer flange outer end face sealing surface  16  is frictionally and self-sealingly connected with the support surface  02 . In the same way, the outer surface  22  of the wall  04  of the hose  01  is self-sealingly connected with the outer flange inner face surface  17  of the outer flange  12 . 
     In connection with an embodiment of the supplying device, but with the use of a fixture  07 , the surface  22  of the wall  04  of hose  01  is directly connected with the support surface  02  in a self-cleaning and frictionally connected manner. 
     While a preferred embodiment of a device for supplying a pressure medium in accordance with the present invention has been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes in, for example the source of supply of the pressure medium, the overall size of the hose and cylinder and the like could be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the following claims.