FR2635718A1 - CYLINDER IN PARTICULAR FOR PRINTING - Google Patents

Abstract

This cylinder is characterized in that it comprises a first internal tubular sleeve 2 adapted to cooperate with a support shaft and a second external tubular sleeve 3 arranged around the first and coaxial with the latter, the outer surface of which is adapted to receive a working coating, the two sleeves being connected by at least one radial spacer 4.

Description

The present invention relates to a cylinder

  especially printing and its manufacturing process.

  Already known in the prior art printing cylinders constituted by tubular steel sleeves whose ends are flared

  to cooperate with the fixing corners of this cylinder

dre on a training tree.

  However, these cylinders have a certain

many disadvantages.

  Indeed, the fixing of the cylinder being carried out by means of wedges, the latter has

  tendency to deform and in order to avoid this deformation

  tion, we increase the amount of material used to make these cylinders, which increases the price of

  returns, the weight and therefore the difficulties of handling

tion and training of these.

  The object of the invention is therefore to solve

  these problems by proposing a cylinder in particular of im-

  primery which is extremely resistant to deformation

tion and as light as possible.

  To this end, the subject of the invention is a cylinder, in particular a printing cylinder, characterized in that it comprises a first internal tubular sleeve adapted to cooperate with a support shaft and a second external tubular sleeve arranged around the

  first and coaxial with it, whose outer surface

  is adapted to receive a working coating, said sleeves being connected by at least

a radial spacer.

  According to different embodiments, the first and second sleeves can be connected by

several radial spacers.

  Advantageously, the or each spacer is in one piece with the sleeves and the cylinder is

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  made of fiber reinforced resin.

  According to another aspect, the invention also has

  ment for a process for manufacturing a cylinder

  dre as described above, comprising a struc-

  fiber structure embedded in resin, characterized by

  what we wrap fibers around a first em-

  cylindrical preprint, so as to form a first

  part of the fiber structure corresponding to the pre-

  mier sleeve, there is around a portion of this part of the structure, a second imprint, delimiting at least one free space determining the thickness and the height of said at least one radial spacer, in which fibers are wound so as to form

  a second part of corresponding fiber structure

  at the spacer, and around this second imprint, fibers are wound so as to form a third part of corresponding fiber structure

to the second outer sleeve.

  The invention will be better understood using

  the description which follows, given only to

  as an example and made with reference to the accompanying drawings, in which:

  - Fig.1 illustrates a manufacturing process

  tion of a first embodiment of a cylinder according to the invention;

  - Fig.2 illustrates a manufacturing process

  tion of a second embodiment of a cylinder according to the invention;

  - Fig.3 illustrates a manufacturing process

  tion of a third embodiment of a cylinder according to the invention; and - Fig.4 shows a sectional view of a

  embodiment of a cylinder according to the invention.

  As can be seen in Fig.1 which illustrates the method of manufacturing a first embodiment of a cylinder according to the invention, this cylinder 1 comprises a first internal tubular sleeve 2 adapted to cooperate with a shaft of support and a second external tubular sleeve 3

  arranged around the first sleeve and coaxial with it

  this. As will be described in more detail by the

  next, the outer surface of the second tubular sleeve

  external area 3 is adapted to receive a coating

  work and the sleeves 2 and 3 are connected by at least one radial spacer 4. This spacer

  is advantageously in one piece with the man-

  chons and as shown in this figure,

  this spacer can be provided at one of the

mites sleeves.

  Advantageously, the cylinder according to the invention

  tion consists of fiber-reinforced resin, for example glass. The structure of glass fibers can be produced by filament winding, this process

  being illustrated in this figure 1.

  This process consists in winding around a first tubular impression 5, fibers so as to form a first part of fiber structure corresponding to the first internal tubular sleeve 2, to arrange around a portion of this first part of fiber structure , a second cavity 6 comprising a tubular mandrel 7 and a stop ring 8, delimiting between them a free space determining the thickness and the height of the radial spacer. Fibers are then wound in this free space so as to form a second part of the structure.

  fibers corresponding to the spacer and finally we wind

  the around this mandrel 7 of the fibers so as to form a third part of the fiber structure

  corresponding to the second external tubular sleeve 3.

  This fiber structure is then embedded in resin using known techniques, these fibers can be pre-impregnated with resin or not, then the resin is hardened in a manner known in

before removing the chuck.

  As shown in FIG. 2, a cylinder according to the invention can also include an internal tubular sleeve 9 and a tubular sleeve

  external 10 connected by a radial spacer 11 available

  placed in the plane of symmetry of the sleeves. This en-

  tretoise is always advantageously made in one piece with the sleeves, for example in resin

reinforced with fibers.

  The manufacturing method of this embodiment of the cylinder according to the invention consists in winding fibers around a first cylindrical cavity 12 so as to form the fiber structure of the first internal tubular sleeve 9, to be arranged around a portion from this first sleeve an imprint 13 comprising two mandrels 14 and 15 defining between them a free space determining the thickness and the height of the spacer, space in which fibers are wound so as to constitute the fiber structure of this spacer and finally to wrap fibers around these mandrels so

  to constitute the fiber structure of the second sleeve.

  This fiber structure is embedded in resin, and this resin then being hardened, before

the withdrawal of the mandrels.

  If we now refer to Fig. 3 which

  represents a third embodiment of a cy-

  liner according to the invention, this can also be-

  consisting of a first internal tubular sleeve 16 around which is disposed a second tubular sleeve

  external 17 coaxial with the first, these sleeves being re-

  linked by several radial spacers, for example two 18 and 19 as shown in this figure.

  These radial spacers can be provided

  regularly seated along these sleeves so

  to improve the mechanical strength of the cylinder.

  The manufacturing process for this sleeve

  is always to wrap around a first em-

  cylindrical preinte 20 of the fibers so as to constitute

  kill the fiber structure of the first tubular sleeve

  area 16, to be placed around this first structure

  re a second imprint comprising two mandrels 21 and 22, delimiting between them a free space in which is placed a core 23 whose lateral faces delimit with the facing surfaces of the mandrels 21

  and 22 respectively, two free spaces in the-

  which are wound fibers so that

  kill the fiber structures of the two spacers 18 and 19 and finally wind around the mandrels 21,22 of the fibers so as to constitute the structure of

  fibers of the second external tubular sleeve 17.

  It should be noted that in the three embodiments which have just been described, the external and internal surfaces of the mandrels can be

  slightly conical so as to facilitate their re-

  line of the cylinder after the resin has been cured.

  As can be seen more particularly in FIG. 4, the or each free end of the cylinder for example 1 can also be provided with an end flange 24 thus blocking this end or

  each free end of the cylinder.

  It should be noted that the cylinder according to the

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  vention can be placed around a fixing tree

  expandable tion like those made for example by

  ACHARD-PICARD, REMY & Cie.

  According to another method of attachment, the ex-

  internal sleeve hollows are flared and adapted to cooperate with clamping corners on a shaft

of support.

  This cylinder made in one piece for example by filament winding of glass fibers, or in other composite materials, can for

  different applications, to be associated in its manufacture

  cation with other elements such as copper,

  aluminum, nickel or carbon.

  Indeed, in the rotary printing sector for example, it is possible to obtain by

  association of such a cylinder with different possibilities

  ties of exterior cladding, the following definitions

  : A) - In the field of flexography: - a screened ink cylinder, laser engraved, comprising glass fibers, a ceramic projection on the external surface of the external sleeve

  and an etching of this ceramic layer.

  - a screened inking cylinder with traditional engraving, comprising glass fibers on which copper is deposited which is engraved and then chromed. - a plate cylinder comprising glass fibers and a rubber coating if

necessary.

  - a bubbler cylinder comprising threads

  glass bres and a rubber coating.

  B) - In the rotogravure field: - a printing cylinder comprising

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  glass fibers and an engraved and chromed copper coating. - a pressure cylinder comprising fibers

  of glass and a rubber coating.

  By its characteristics of very high mechanical resistance and its great lightness, the cylinder according to the invention is therefore particularly well suited to the rotary printing sector, either in gravure printing or in flexography, for printing by example of food packaging. Indeed, these printing techniques require, for the different formats, a very frequent change of cylinders which

  are currently constructed of steel and require

  for their handling lifting means

  motorized and a large workforce.

  The cylinder according to the invention of a much lower manufacturing cost than those of the prior art, moreover has a much lower weight, which results in greater ease of operation for the installation of this cylinder in the printing elements, greater ease of training and therefore energy saving, the elimination in most cases of motorized lifting means specially adapted for this purpose, greater ease of storage, a possibility of reuse cylinders and greater safety

when handling it.

  Furthermore, it is extremely easy to adjust the outside diameter of the tubular sleeve

  external during the manufacture of the cylinder in use

  sant mandrels determining an appropriate spacer height, which allows to adjust the development

of the cylinder.

  In the case where the cylinder according to the invention is fixed by corners on a drive shaft, these can cooperate with surfaces of complementary shape to the ends of the first internal sleeve. The or each end flange is then fixed only on the external sleeve so that

  only the inner sleeve tends. to distort.

  Although only glass fibers have been mentioned, fibers of a material other than glass can also be used for manufacturing

of a cylinder according to the invention.

Claims (10)

  1. Cylinder, in particular for printing, character   terized in that it comprises a first tubular sleeve   internal space (2; 9; 16) adapted to cooperate with a support shaft and a second external tubular sleeve (3; 10; 17) disposed around the first and coaxial with it, the external surface of which is suitable for receive a working coating, the two sleeves being connected by at least one radial spacer (4; 11; 18, 19).   2. Cylinder according to claim 1, charac-   terized in that said spacer (4; 11; 18,19) is   in one piece with the sleeves.   3. Cylinder according to claim 1 or 2, characterized in that said spacer (4) is provided   at one end of the sleeves (2,3).   4. Cylinder according to claim 1 or 2,   characterized in that said spacer (11) is pre-   view in the plane of symmetry of the sleeves (9,10).   5. Cylinder according to claim 1 or 2, characterized in that the sleeves (16,17) are connected by several spacers (18,19).   - 6. Cylinder according to claim 5, charac-   terized in that said spacers (18,19) are regularly distributed along the length of the sleeves (16,17).   7. Cylinder according to any one of the re-   previous vendications, characterized in that the or each free end of the cylinder has a flange end (24).   8. Cylinder according to any one of the re-   previous vendications, characterized in that it is   made of fiber reinforced resin.   9. Cylinder according to any one of the re-   previous vendications, characterized in that the fibers are glass fibers.   10. Method of manufacturing a cylinder   according to any one of the preceding claims,   comprising a fiber structure embedded in resin, characterized in that fibers are wound around a first cylindrical impression (5; 12;   ) so as to form a first part of struc-   fiber size corresponding to the first sleeve   dull (2; 9; 16), there is around a portion of this part of the structure, a second imprint (6,7,8; 13, 14,15; 21,22). delimiting at least one free space determining the thickness and the height of said at least one radial spacer, in which fibers are wound so as to form a second   part of the fiber structure corresponding to the   height rod and the fibers are wound around this second imprint so as to form a third part of the fiber structure corresponding to the second sleeve external (3; 10; 17).