EP0987109B1 - Automatic obturation device for through holes for air in a cylinder, particularly for support cylinders and compensating sleeves - Google Patents

Description

The present invention relates to an automatic shutter device air passage holes in a cylinder, especially for cylinders support and compensation sleeves, as well as an arrangement comprising a support cylinder and a sleeve intended to be mounted coaxially on the support cylinder, such as a printing sleeve, with the interposition of a printing sleeve compensation.

We know ways to mount sleeves on cylinders hollow. These means consist in making and using sleeves which are adjusted tight relative to the support cylinder and which are mounted on said cylinder by generation of a pressurized air film in the interface area. AT For this purpose, the support cylinder is hollow and forms a closed enclosure. A pressurized air supply to this closed enclosure is provided at one of the ends while nozzles, generally distributed along a generator, release this pressurized air. From the nest coaxial of the sleeve, the first hole creates a film of pressurized air at the interface, expands the sleeve radially; which, like a cushion of air, allows the introduction of this sleeve over the entire length of the cylinder, if need.

As soon as the pressurized air supply is interrupted, the sleeve returns to its nominal diameter and the radial clamping forces are sufficient for the keep in place, even in operation, during rotation.

If this type of assembly is well known (see document EP-A-0 510 744), there is a problem when it it is necessary to mount, in a coaxial way superimposed, two sleeves on the same hollow cylinder.

Indeed, to be able to mount a printing sleeve with a diameter given on a support cylinder of a given diameter, not adapted to that of this sleeve, the use of a compensation sleeve is of interest certain. For the same metal support cylinder, it is possible to mount first of all a compensation sleeve then on this sleeve compensation, a printing sleeve with its plate or engraving. From this fact, the difference in thickness corresponding to given developments is distributed over the two compensation and printing sleeves. The printing sleeves are made of composite material and the thicknesses are generally limited for weight reasons because even if the composite is much lighter than steel, you have to stay in the weights of the sleeve 15 kg final weight so that they can be handled by just one person. This limits its thickness.

In addition, the stiffness of a very thick sleeve can also another problem is mounting problems.

The only other alternative to the compensating sleeve would be to have a large fleet of hollow support cylinders with all dimensions suitable for different diameters of printing sleeves. This would allow limit the thickness of the printing sleeve by choosing a cylinder larger diameter support. But in this case, it's the support cylinders which have to be changed, which is particularly delicate and time consuming because of the weight which makes them very heavy to maneuver. In addition, the cost of park is very strongly increased, which makes this solution totally inadequate.

If so, we use the compensating sleeve, other problems arise since it is necessary to coaxially mount one sleeve on another of same nature, the coefficients of friction being able to prove important. Of more, mounting under pressure can only be done from the same single source of pressurized air, namely the enclosure formed by the cylinder hollow.

A first problem which arises, arises from the fact that the holes are distributed along a generator and all open, which generates a poor pressure distribution. Indeed, if the first holes are clogged, pressurized air tends to carry over other holes and limit the formation of an air film between the sleeve and the cylinder. Pressure limited leads to less radial expansion and strength mounting. If the pressure is too high, it risks at the end of assembly where all the holes are closed to degrade the sleeve, which is not a solution satisfactory.

In the case of fitting a compensating sleeve, another constraint is that the compensating sleeve must be blocked on the cylinder support after mounting while allowing posterior mounting under pressure of the printing sleeve on this compensation sleeve.

The object of the invention is to alleviate these problems and to allow a easy fitting of sleeves, either in the case of a single sleeve directly on the support cylinder, i.e. in the case of a compensation sleeve with coaxial printing sleeve. The solution must be achievable at costs low for the equipment of the existing fleet and at low additional costs for new.

To this end, the automatic shut-off device for through holes of air in a cylinder according to the invention, in particular for the support cylinders sleeves and for compensation sleeves, includes, inserted in the thickness of the wall of this cylinder, a support, with an interior passage, a seat and a valve movable in translation in the support and capable of take two positions, the first in which the valve comes into contact watertight with said seat and the other in which it is recessed so as to leave a passage, this valve having a cone-shaped head and a seat provided with an interior passage of shape combined with that of the head for ensure a seal when the head is pressed against the seat, in the interior passage, slightly projecting from the exterior surface and a position in which the head is set back from the seat, leaving thus a passage.

According to a variant, the valve has a head with a flange provided for come to press tightly against the face opposite the seat as well that an element forming a stop by angular displacement, so as to ensure sealing when the stop member is in a first position angular and generate a passage by withdrawal of the flange relative to the seat when the stop member is in a second angular position.

The stopper element is a pin.

According to a particular arrangement, in particular for mounting on the existing fleet cylinders, the different elements, support / seat / valve are mounted in an insert designed to be added in the thickness of the cylinder.

• figure 1, une vue en perspective schématique d'un cylindre support,
• figure 2, une vue en perspective schématique du même cylindre support de la figure 1 et d'un manchon de compensation en cours de montage,
• figure 3, une vue en coupe de l'extrémité d'un manchon de compensation monté sur un cylindre support,
• figure 4, une vue identique à celle de la figure 3 mais avec un manchon d'impression en cours de montage sur le manchon de compensation,
• figure 5, une vue en éclaté des différents éléments constituant l'obturateur à commande automatique,
• figure 6, une vue identique à celle de la figure 4 mais avec un obturateur à commande automatique différent,
• figures 7A et 7B, une vue d'un obturateur particulier à verrouillage manuel, dans les deux positions de montage et de positionnement, et
• figure 8, une vue en éclaté des différents éléments constituant l'obturateur à commande automatique des figures 7A et 7B.

The invention is now described according to a particular, nonlimiting embodiment, with reference to the appended drawings in which the different figures represent:

• FIG. 1, a schematic perspective view of a support cylinder,
• FIG. 2, a schematic perspective view of the same support cylinder of FIG. 1 and of a compensation sleeve during assembly,
• FIG. 3, a sectional view of the end of a compensation sleeve mounted on a support cylinder,
• FIG. 4, a view identical to that of FIG. 3 but with a printing sleeve being mounted on the compensation sleeve,
• FIG. 5, an exploded view of the various elements constituting the shutter with automatic control,
• FIG. 6, a view identical to that of FIG. 4 but with a different shutter with automatic control,
• FIGS. 7A and 7B, a view of a particular shutter with manual locking, in the two mounting and positioning positions, and
• Figure 8, an exploded view of the various elements constituting the shutter with automatic control of Figures 7A and 7B.

In FIG. 1, the cylinder 10 is a metal support cylinder which is hollow and comprises at each of its two ends an axis 12, 14 of rotation, both intended to cooperate with machine bearings, this known way.

One 14 of the axes includes a central bore with a tip quick connection (not shown) to connect the enclosure 16 formed by the interior from the cylinder to a source 15 of pressurized air.

According to the invention, this cylinder comprises a particular distribution which is optimized, without being limiting, with a first set 18 of nozzles regularly distributed at the periphery on the same circle and several games 20 nozzles identical to those of the first game, distributed at the periphery of successive circles along a generatrix.

On this cylinder 10, provision is made to mount a sleeve 22, the occurrence a compensating sleeve. It would be the same if we went up a printing sleeve, except that it would not have nozzles for receive a sleeve coaxially.

This compensating sleeve 22 includes a first set 24 of nozzles evenly distributed as the support cylinder nozzles, as well as several secondary games 26 also like the secondary games of the support cylinder.

There must be strictly coincidence of the different nozzles after complete mounting of the compensating sleeve on the support cylinder. In this Indeed, it is advantageous to provide index markers on the edge of the support cylinder and compensating sleeve.

Each nozzle of each compensating sleeve is equipped with 28 individual means of automatically closing each nozzle of each different games.

These individual means of automatic shutter each comprise a shutter 30, an exploded representation of which is shown in FIG. 5, the application concerning sleeves made of composite material.

Each shutter 30 comprises a support 32, a seat 34 and a movable valve 36.

The support 32 is a ring 38 whose internal passage 40 is flanked, in this case 6 sides.

This support is fixed flush with the inner side of the compensation, in an oversize 42 centered on the corresponding nozzle, thus as shown in Figures 3 and 4.

The seat 34 is a ring 44, fixed in a bore 46, flush exterior side. This ring 44 has an interior passage 48 of conical shape as shown in figure 5.

The movable valve 36 comprises a body 50 having a diameter allowing the sliding in the inner passage 40 with sides of the ring and a head 52 of profile combined with that of the interior passage 48 of shape conical ring 44 of the seat. This valve can take two positions, one in which the valve is recessed, with the head 52 outside the passage interior 48 and the other in which the valve is supported, with the head 52 pressed against the wall of the conical interior passage, thus ensuring sealing.

A spring 54 is interposed between the support 32 and the head 52 of the valve 36 so as to press this valve against the seat 34. The stiffness of this spring is relatively weak since its role is limited to compensating for the weight the valve to hold it against the seat when the valve is under gravity in the head / body direction.

The mounting of such a compensation sleeve 22 on a cylinder 10 support is carried out as follows.

The inner enclosure 16 of the support cylinder 10 is pressurized if although air escapes through sets 18 and 20 of nozzles.

The compensation sleeve is inserted which hides the nozzles of the first set 18 of nozzles. An air film is generated between the surface the outer surface of the support cylinder and the inner surface of the compensation. Balancing is partly improved by the fact that the nozzles are distributed asymmetrically with a larger number upon entry, without increasing pressure.

Generally, the support cylinders are made of metal and the sleeves are made of composite material, so the coefficient of friction is acceptable and the compensation sleeve is easy to mount.

It is noted that the air under pressure tends to press the head 52 of the valve 36 against the passage 48 inside the seat 34, in the same direction as the force exerted by the spring, so that the air cannot escape. In addition, in end of insertion of the sleeve, all the holes are in coincidence but the nozzles of the different sets 24 and 26 are well closed. If these nozzles were not blocked, the pressurized air film would be interrupted, preventing then any movement of the sleeve on the support cylinder.

It can be seen that, in the position shown in FIG. 3, the end of the head 52 of each valve protrudes slightly from the outer surface of the compensation sleeve 22, through the interior passage 48 of the seat.

In the case of a compensating sleeve mounting, the following step consists in coaxially inserting a printing sleeve 56 bearing a plate or an engraving 58, on the compensation sleeve 22 which comes to be mounted on the support cylinder.

To achieve this, the pressurized air supply is interrupted, which which immobilizes the compensation sleeve on the cylinder support.

The printing sleeve is then introduced through its end onto the compensation sleeve, until covering the nozzles of the first set. the valves of the individual automatic shutters of the nozzles of this first game retracts to allow passage through the nozzles of the first game.

The supply of pressurized air is then resumed. Air under pressure passes through the nozzles of the support cylinder and through the plugs open the compensation sleeve, to create an air film between this compensation sleeve which is stationary and the printing sleeve at introduce.

We note that most of the air under pressure is directed towards the open nozzles, leaving the compensation sleeve stationary while generating a good quality air film between the compensation sleeve and the printing sleeve, especially since the number of holes is more important in the first game than in the secondary games.

As the printing sleeve is inserted on the compensation sleeve, the valves are open which improves the distribution of the pressurized air film at the interface.

When the print sleeve is fully inserted, the power supply pressurized air is interrupted which ensures the immobilization of the printing sleeve on the compensation sleeve, itself immobilized on the support cylinder.

Figure 6 is an alternative embodiment of the valve whose body is provided with a longitudinal blind hole and radial air passage holes. In in this case, the valve body remains in abutment on the support without passing through it.

Guidance is then obtained in this particular embodiment by the differences between the dimensions of the valve body and those of the overbore in which it is movable in translation and by the coaxial spring.

In FIGS. 7A and 7B, a locking variant has been shown. manual, identical references bearing the same increased references of 100. This variant provides a movable valve 136 which is pushed by a spring 154 as in the previous assembly. The ring 138 is identical to the previous ring 38, with an internal passage 140 with a hexagon for allow the body 150 of the valve to slide. This body 150 has a end 151 which is of form conjugate with that of the hole made in the support cylinder 10 for indexing.

The ring 144 of the seat 134 is of simple shape with passage 148 inside cylindrical, combined with that of the body 150 of the valve. A collar 153 forming a stop is added to the body and secured to it to avoid passage of this body 150 of the valve through the passage 148 and especially for form a seal with the face opposite the seat 134.

This arrangement also provides means 160 for locking in position which include a pin 162, arranged transversely to the body 150 of the valve, immediately above the flange 153, provided to cooperate with an open housing 164, of a shape adapted to receive this pin in a given first angular position.

In this position shown in Figure 7A, the valve is in position high and the collar seals with the face opposite the ring 144 of the seat 134. The pressurized air reinforces this plating effect. In in this case, an air film is formed between the sleeve 22 and this cylinder support 10, in the case where the enclosure 16 constituted by the hollow interior of the support cylinder is supplied with pressurized air.

When the sleeve must be immobilized, it is enough, after positioning the sleeve relative to the support cylinder by means of external marks, rotate the valve, using a simple screwdriver blade for example, a slot 166 being formed at the end of the valve on the head 152. The valve, once turned angularly, has an offset between the pin 162 and the housing 164 provided for receiving it, so that the valve is kept in the open position because the flange is moved away from the face of the seat ring on which it was resting. In addition, the end 151 of the valve body enters the hole in the support cylinder, which allows a check of the correct indexing.

The compensation sleeve is thus positioned and immobilized on the support cylinder 10. In addition, the pressurized air admitted into the enclosure 16 constituted by the hollow body of this cylinder passes through the sleeve of compensation which allows the mounting of the printing sleeve with its snapshot, easily, as in the main embodiment.

Note that in this variant, it is certain that the sleeve of compensation cannot in any case be angularly offset from the support cylinder, even during operation, which is particularly appreciable for sleeves of large dimensions because the masses in game are very important and the details of the odds more difficult to respect.

We note that these individual means of automatic shutter can be manufactured and mounted in an insert, then placed on the cylinders or sleeves, a posteriori.

In the case of a support cylinder having to receive a single sleeve, the sealing means are mounted directly on the support cylinder because this improves the pressure distribution and makes it possible to obtain an air film of best quality. The shutters are then directly introduced into the thickness of the cylinder. In this case, it is even more advisable to resort to an insert which is screwed into a threaded hole machined in the thickness of the wall of the cylinder, said insert comprising all of the elements support / seat / valve / spring which have just been described for the sleeve compensation.

This eliminates the risks of certain sealing devices ball (see document EP-A-0 510 744) in which each ball is flush with the surface, simply held by the lips of the hole having a very small thickness of material. Indeed, even with pressures of 3 to 4 bars simply, it is possible to transform a ball into a very dangerous projectile.

In addition, such ball shutters are very delicate to mount on the support cylinders.

In order to combat the risks of overpressure which could lead to bodies responsible for subjecting such arrangements to checks associated with pressure vessels, it makes sense to have them on the cylinders safety valves calibrated to a maximum safety pressure beyond from which the pressurized air escapes.

It is then noted that such a valve can be produced by means a valve according to the invention because it suffices to orient the assembly support / seat / valve upside down and mount a stiffer spring, calibrated to correspond to a given maximum pressure.

Within the framework of the associated improvements, it is also possible to place a ring of felt-like fibrous material at the end of the cylinder support so as to ensure, simultaneously with the introduction, a cleaning of the inside of the sleeve to be fitted, thus avoiding the presence of particles detrimental to the proper sliding of the sleeve on the cylinder. Setting protrusion of such a ring should be a few tenths knowing that these materials are compressible in high proportions.

Claims (9)

1. An automatic obturation device for through holes for air in a cylinder, particularly for sleeve support cylinders (10) and for compensating sleeves (22), including within the wall thickness of said cylinder a support (32) with an internal passage (40), a seat (34) and a valve (36) capable of translational movement in the support and capable of adopting two positions, a first position in which the valve comes into airtight contact with said seat and a second in which it is retracted so as to leave a passage, characterised in that the valve (36) has a head (52) of conical form and the seat (34) is equipped with an internal passage (48) the form of which is matched to that of the head to ensure airtightness when the head abuts against the seat in the internal passage while projecting slightly with respect to the external surface, and [the valve has] a position in which the head is retracted with respect to the seat, thereby leaving a passage.
2. An automatic obturation device for through holes for air in a cylinder, particularly for sleeve support cylinders (10) and for compensating sleeves (22), including within the wall thickness of said cylinder a support (132) with an internal passage (140), a seat (134) and a valve (136) capable of translational movement in the support and capable of adopting two positions, a first position in which the valve comes into airtight contact with said seat and a second in which it is retracted so as to leave a passage, characterised in that the valve (136) has a head (152) with a collar (153) provided to abut in an airtight manner against the opposed face of the seat (134), and an element (162, 164) forming a stop by angular displacement so as to ensure airtightness when the element forming a stop is in a first angular position and to produce a passage by retraction of the collar with respect to the seat when the element forming a stop is in a second angular position.
3. An automatic obturation device for through holes for air according to Claim 2, characterised in that the element forming a stop is a pin (162) transverse with respect to the valve and provided to be retracted into an open housing (164) formed in the opposed face of the seat in the first position.
4. An automatic obturation device for through holes for air according to Claim 2 or 3, characterised in that the valve head includes a slot (166) adapted to co-operate with a control blade passing from the outside through an internal passage (148) in the seat (134).
5. An automatic obturation device for through holes for air according to one of the preceding claims, characterised in that it includes a return spring (54,154) interposed between the support and the valve and exerting a radial force from the interior to the exterior.
6. An automatic obturation device for through holes for air according to one of the preceding claims, characterised in that the different elements, support/seat/valve, are mounted in an insert provided to the incorporated in the thickness of the cylinder.
7. An arrangement comprising a support cylinder (10) and a sleeve, such as a printing sleeve, adapted to be assembled coaxially on the support cylinder, a compensating sleeve being interposed and the support cylinder (10) being a hollow cylinder the interior (16) of which is capable of being connected to a compressed air source (15) and including nozzle apertures (18, 20) distributed on its periphery, the compensating sleeve (22) including nozzle apertures (24, 26) distributed so as to coincide with the nozzle apertures in the support cylinder, automatic obturation devices being inserted in the nozzles formed in the compensating sleeve, and comprising a support (32) with an internal passage (40), a seat (34) and a valve (36) capable of translational movement in the compensation sleeve and capable of adopting two positions, a first position in which the valve comes into airtight contact with said seat and a second in which it is retracted so as to leave a passage, the valve (36) having a head (52) of conical form and the seat (34) being equipped with an internal passage (48) the form of which is matched to that of the head to ensure airtightness when the head abuts against the seat in the internal passage while projecting slightly with respect to the external surface, and [the valve having] a position in which the head is retracted with respect to the seat, thereby leaving a passage, this retraction with respect to the seat being caused by the internal cylinder face of the printing sleeve fitted over the compensating sleeve.
8. An arrangement according to Claim 7, characterised in that the support cylinder (10) is provided with safety valves calibrated to a maximum safety pressure beyond which the compressed air escapes.
9. An arrangement according to Claim 7 or 8, characterised in that a ring of fibrous material such as felt is disposed at the end of the support cylinder (10) at which the compensating sleeve (22) is fitted over the support cylinder, and is adapted to ensure cleaning of the internal surface of the sleeve as it is fitted.

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