FR2789626A1 - Vent valve control for an support cylinder air vent assembly, comprises a slider assembly movable within a barrel assembly within the support cylinder assembly - Google Patents

Abstract

The valve assembly is mounted within a barrel (34) of a support cylinder assembly. A bore is located through the barrel and valve assemblies such that a nozzle is formed that is perpendicular to the barrel. The valve assembly slides within the barrel and such that the bore is either open or closed. This controls the airflow through a nozzle assembly (20).

Description

DEVICE FOR SEALING AIR HOLES IN A

  CYLINDER, ESPECIALLY FOR SUPPORTED CYLINDERS AND

COMPENSATION SLEEVES

  The present invention relates to a device for closing air passage holes in a cylinder, in particular for support cylinders and

compensation sleeves.

  Thin printing sleeves are widely used in flexographic printing. They are usually mounted with a tight fit on a support cylinder, and are used as a support for clichés

or engravings.

  To be able to mount a thin printing sleeve of a given diameter on a support cylinder of a given diameter, not suitable for that of this thin sleeve, use is made of a compensation sleeve placed between the support cylinder and the thin sleeve printing. Thus, for the same metal support cylinder, it is possible to mount thin printing sleeves of different internal diameters, by choosing the sleeve of

  adequate thickness compensation.

  Means are known for mounting with a tight fit of the sleeves on hollow support cylinders. These means consist in creating a film of pressurized air in the interface zone in order to slide the thin sleeve on the support cylinder during assembly. For this purpose, the support cylinder is hollow and forms a closed enclosure. A supply of pressurized air to this enclosure is provided while nozzles opening onto the external face of the support cylinder allow this pressurized air to be released. From the coaxial fitting of the thin sleeve, the first nozzle covered by the sleeve creates a film of pressurized air at the interface, which expands radially at least inside the sleeve, which allows the introduction of

  this sleeve over the entire length of the cylinder.

  As soon as the pressurized air supply is interrupted, the sleeve returns to its nominal diameter and the radial tightening forces are sufficient for the

  keep in place even during operation during rotation.

  The present invention relates to a device for closing air passage holes in a cylinder, which allows easy mounting of thin sleeves, either directly on a support cylinder or on a compensation sleeve. The solution must be achievable at low costs for

  equipping the existing fleet and at low additional costs for new ones.

  To this end, the invention relates to a device for shutting off a nozzle for the flow of a compressed fluid from the inside to the outside of a support cylinder or of a compensated support cylinder assembly comprising a support cylinder and a compensation sleeve, designed to receive a thin sleeve fitted tightly, characterized in that it comprises a drawer, provided with a conduit, which can translate, in a direction substantially perpendicular to the nozzle, in a chamber, interposed transversely to said nozzle, said drawer being capable of occupying two positions, a first so-called through position, in which the duct allows the flow of air through the nozzle, and a second so-called closed position, in which

  the drawer prevents the flow of air through the nozzle.

  Preferably, the chamber is delimited by a barrel which is screwed into a bore produced in the support cylinder or the compensation sleeve,

  of longitudinal axis, and the drawer is a piston which can slide in the barrel.

  According to a first embodiment, the conduit consists of a

  groove on the outer surface of the piston.

  According to a second embodiment, the conduit consists of a bore which passes right through the piston, and the piston comprises means for stopping in rotation provided so that the bore is always in the

extension of the nozzle.

  Other characteristics and advantages will emerge from the description which

  will follow of the device according to a preferred embodiment, description given

  by way of example only, with reference to the appended drawings in which: - Figure 1 is a view in longitudinal section of the invention, thin sleeve during mounting, - Figure 2 is a view in longitudinal section of the invention, thin sleeve mounted, - Figure 3 is an exploded view of the device of the invention - Figure 4 is an elevational view of the control means of the device, - Figure 5 is a longitudinal sectional view of a simplified embodiment of the invention, and Figures 6A and 6B are two views in longitudinal section of a means

  complementary indexing, in its two positions.

  In Figure 1, there is shown a support cylinder 10, a compensating sleeve 1 2 fitted tightly fitted on said support cylinder, and a sleeve

  thin 14 during assembly or disassembly.

  The support cylinder 10, generally metallic, is closed at its two ends in order to form a closed enclosure 16. Means for supplying compressed air to the closed enclosure 16 are also provided at one of the

ends of the support cylinder.

  The mounting of the compensating sleeve on the support cylinder is carried out in the known manner, and does not constitute the subject of the present request unless provision is made for indexing means which will be described later. Also, in the remainder of the description, it will be considered that the support cylinder 10 and the compensation sleeve 12 form only one and

  same part called support cylinder 1 1 compensated.

  This compensated support cylinder 11 further comprises an exterior surface 18, and nozzles 20 which constitute conduits capable of allowing the flow of compressed air from the interior to the exterior of this compensated support cylinder. According to a preferred embodiment, these nozzles are arranged 90 in the same transverse plane near one of the

  ends of the compensated support cylinder.

  Opposite, the thin sleeve 14 includes an inner surface 22 whose diameter is equal to or slightly less than the diameter of the outer surface 18 of the support cylinder. Each nozzle 20 comprises a closure device 24 which allows or not the passage of compressed air from the inside to the outside of the support cylinder. This closure device comprises a drawer 26 which can translate, in a direction substantially perpendicular to the nozzle, in a chamber 28 which splits the nozzle 20 into two parts, a first part called the inlet which connects the closed enclosure 16 to room 28, and a second part called

  outlet which connects the chamber 28 to the outside of the compensated support cylinder.

  The drawer 26 comprises a duct 30, and can occupy two positions, a first so-called through position, in which the duct 30 is aligned with the adjustment 20 allowing the flow of air from the inlet to the outlet of the nozzle, and a second so-called closed position, in which the slide 26

  prevents air flow from the inlet to the outlet of the nozzle.

  The drawer 26 further comprises control means 32 which

  allow to actuate said drawer 26.

  According to an embodiment illustrated in Figures 1, 2, and 3, the chamber 28 is delimited by a barrel 34 which is screwed into a bore made in the compensation sleeve 12, of longitudinal axis, and opening at one of the ends of the sleeve. This barrel 34 also includes orifices 38 in the extension of the nozzle 20 so that said nozzle opens out.

inside the barrel.

  In this case, the slide 26 is a piston 40 which can slide in the barrel 34 and which comprises, in addition to the conduit 30 and means 32 for

  control, guide means 42, and sealing means 44.

  As illustrated in FIG. 3, the piston 40 includes at each of its ends a bearing materialized by a reduction in diameter. The first scope 46, oriented towards the inside of the barrel, is mounted with an adjustment

  sliding in a corresponding bore in the barrel 34.

  The second bearing surface 48, which projects outside the sleeve 10, is mounted with a sliding adjustment in a ring 50 screwed into the barrel at the level of the through end of said barrel 34. The sealing means 44, arranged on the side and on the other side of the conduit 30, are produced by O-rings which are housed in grooves made at

the surface of the piston 40.

  According to a first embodiment, the conduit 30 is produced by a bore which passes right through the piston 40. In this case, means 52 for stopping the piston in rotation are provided so that the bore 30 is always in the extension of the nozzle. As illustrated in FIGS. 1, 2 and 3, these means 52 are produced by a stud screw 54, accessible from the outside of the support cylinder, which is screwed into the support cylinder, and the end of which is housed in a groove 56 formed on a generator of the

first litter 46.

  According to a second embodiment, the conduit 30 can be produced by

  a groove formed on the surface of the piston 40.

  The control means 32 are attached to the second bearing surface 48, and comprise a crown 58 which connects the ends of the pistons of the various closure devices, visible in FIG. 4. Thus by actuating the

  crown 58, one acts simultaneously on all shutter devices.

  The operation of the shutter device is now described in

see Figures 1 and 2.

  To mount a thin sleeve 14 on a support cylinder 11 compensated according to the invention, the closure devices are in the on position. Thus for each device, the duct 30, arranged in the extension of the nozzle 20, allows the flow of compressed air from the inside to the outside of the compensated support cylinder 11, as illustrated in

Figure 1.

  As soon as the nozzles are covered by the thin sleeve 10, the sleeve creates a film of pressurized air at the interface, which expands the sleeve radially, which allows the introduction of this sleeve over any

the length of the cylinder.

  As soon as the thin sleeve is in place, the user pulls on the crown 58 in order to position the closure devices in the closed position and to prevent the flow of compressed air from the inside to the outside of the

  compensated support cylinder, as illustrated in figure 2.

  As soon as the pressurized air supply is interrupted, the thin sleeve returns to its nominal diameter and the radial tightening forces are sufficient

  to keep it in place even in operation, during rotation.

  To limit the risks of suction cup phenomenon during the operation of the piston 40, a conduit 60 is provided in order to connect the interior of the chamber 28 to the exterior of the cylinder. A conduit 61 of very small diameter also puts in

  relationship this chamber with conduit 30 for the same reasons.

  FIG. 5 shows a simplified variant of the device of the invention. In this case, the chamber 28 is produced directly in the support cylinder, the barrel 34 then being eliminated, and the control means 32 comprise for each device a knurled ring fixed to

the end of the piston.

  Of course, the present invention is not limited to the single preferred embodiment described above. On the contrary, it covers many variants both in terms of the shapes and dimensions of the drawer and the shapes

control means.

  Finally, the closure device can also be placed in the support cylinder proper in the case of mounting the thin sleeve.

  directly on the support cylinder.

  In FIGS. 6A and 6B, means 62 have been shown for indexing the

  compensation sleeve 12 with respect to the support cylinder 10.

  Such means are interposed between the various sealing devices if the compensation sleeve is equipped with several. Of

  more, these means are mounted directly in the support cylinder 10.

  These indexing means 62 comprise a first housing 64 formed in the thickness of the cylinder, along the longitudinal axis as well as a

  second housing 66, radial, opening into the first housing.

  A finger 68 movable in the second housing can take two positions, one retracted under the effect of a return spring 70 and the other, in

  projection, under the effect of maneuvering means 72.

  These maneuvering means 72 comprise in a particular embodiment an insert 74 screwed into the first housing with a threaded shaft 76 which can rotate under a manual action of the operator, thanks to a knurled button 78. This shaft is fixed in translation and receives a threaded slide with a first straight cylindrical part and a second part.

  cylindrical-conical, mounted screwing on this shaft.

  The slide receives in support by its lower end the movable finger 68. i15 The slide can take two extreme positions, one corresponding to a cooperation of the movable finger with the right cylindrical part, the finger is retracted and the other to a cooperation of the mobile finger with the part

  cylindro-conical, the finger protrudes.

  It suffices to provide a through or blind hole in the compensation sleeve, of profile adapted to receive the upper end of this finger. Consequently, the penetration of the movable finger guarantees good indexing. Alternatively, the slider can also be fixed on a sliding rod, not threaded, the movements of the slider being linked to those of the

sliding rod.

Claims (10)

  1. Device for closing a nozzle (20) for the flow of a compressed fluid from the inside to the outside of a support cylinder (10) or of a compensated support cylinder assembly (11) comprising a support cylinder (10) and a compensating sleeve (14), characterized in that it comprises a drawer (26), provided with a conduit (30), which can translate, in a direction substantially perpendicular to the nozzle (20), in a chamber (28), interposed transversely to said nozzle, said drawer (26) being capable of occupying two positions, a first so-called through position, in which the duct (30) allows the flow of air through the nozzle, and a second so-called closed position, in which the slide valve (26) prevents the flow of air at through the nozzle.   2. Sealing device according to claim 1, characterized in that the chamber (28) is delimited by a barrel (34) which is screwed into a bore produced in the support cylinder (10) or the compensation sleeve (12) , of longitudinal axis, and in that the slide (26) is a piston (40) which can slide in the barrel (34).   3. obturation device according to claim 2, characterized in that the conduit (30) consists of a groove formed on the outer surface of the piston (40).   4. Sealing device according to claim 2, characterized in that the conduit (30) consists of a bore which passes right through the piston (40), and in that said piston (40) comprises means (52) stop in rotation provided so that the bore (30) is always in the extension of the nozzle.   5. obturation device according to any one of claims   above, characterized in that it comprises a conduit (60) which connects the interior of the chamber (28) to the exterior of the support cylinder or of the compensation sleeve in order to limit the risks of suction cup phenomenon during the operation of the piston (40).   6. obturation device according to any one of claims   previous, characterized in that the drawer comprises control means (32). 7. Support cylinder (10) or compensated support cylinder (11) equipped with at least two closure devices regularly distributed according to the   claims 1 to 6, in the same transverse plane near one of the ends of the support cylinder.   8. Support cylinder (10) or compensated support cylinder (11) according to claim 7, characterized in that it comprises means (32) for   simultaneous control of shutter devices.   9. Support cylinder (10) or compensated support cylinder (11) according to claim 8, characterized in that it comprises a crown (58) which connects the ends of the pistons of the various closure devices and which allows   simultaneous action on said shutter devices.   10. Compensated support cylinder, characterized in that it comprises means for indexing the compensation sleeve relative to the support cylinder. 1 1. compensated support cylinder according to claim 10, characterized in that the indexing means comprise a first housing (64) formed in the thickness of the cylinder, along the longitudinal axis and a second housing (66) radial , opening into the first housing, and a finger (68) movable in the second housing which can take two positions, one retracted under the effect of a return spring (70) and the other, projecting under   the effect of maneuvering means (72).