EP0795407A1 - Device for the stimulated ejection of material under pressure by means of a closable nozzle - Google Patents

Device for the stimulated ejection of material under pressure by means of a closable nozzle Download PDF

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Publication number
EP0795407A1
EP0795407A1 EP97400545A EP97400545A EP0795407A1 EP 0795407 A1 EP0795407 A1 EP 0795407A1 EP 97400545 A EP97400545 A EP 97400545A EP 97400545 A EP97400545 A EP 97400545A EP 0795407 A1 EP0795407 A1 EP 0795407A1
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EP
European Patent Office
Prior art keywords
nozzle
jet
emission
deformable member
pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP97400545A
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German (de)
French (fr)
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EP0795407B1 (en
Inventor
Thierry Colombat
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Markem Imaje SAS
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Imaje SA
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
    • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
    • B41J2/01—Ink jet
    • B41J2/135—Nozzles
    • B41J2/165—Preventing or detecting of nozzle clogging, e.g. cleaning, capping or moistening for nozzles

Definitions

  • the present invention relates to a device allowing the emission of a stimulated jet of material under pressure by a closable nozzle.
  • a device can be used in particular for producing ink jet printer printheads.
  • inkjet printers generate jets or drops of ink using ejection nozzles.
  • the control of the ink pressure upstream of the nozzle makes it possible to start or stop the flow of the fluid through the orifice of the nozzle.
  • the quality of stops and starts essentially depends on the duration of the pressure transients during these phases. A clear transition in pressure values makes it possible to obtain good directivity of the jet at start-up and prevents the formation of an ink deposit at the outlet of the nozzle when the jet stops.
  • One of these solutions consists in sealing the nozzle between two operating phases.
  • Document EP-A-54 905 discloses the use of an electromagnetic closure means of the jet emission nozzle to prevent ambient air from entering it and applies to the case where the ink of impression is a magnetic fluid. We explain in particular how the problems of the supply circuit for a magnetic fluid are solved.
  • US-A-4 199 767 describes a nozzle closure means constituted by a plate which can move in front of the nozzle by a magnetic field.
  • a similar idea is presented in IBM Technical Disclosure Bulletin, vol. 18, n ° 12, May 1976. In the systems proposed, which bring two solid parts into contact to close an orifice, it is however necessary to provide sufficient electromagnetic forces to detach the contacts following a prolonged stop, a ink residue around these contacts that may have dried.
  • the document FR-A-2 540 044 describes a solution for closing the nozzle using solenoid valves fitted with a flexible part mounted on the rod of a translation element. This function is used to generate drops at the frequency of nozzle openings and closings.
  • This solution is taken up in document WO 91/00808 in the case of use in deviated continuous jet technology.
  • the electromagnetically controlled translation element bears on the nozzle by means of a flexible part and isolates the ink from the ambient environment during stops. This solution prevents the ink from flowing and drying out of the nozzle.
  • the opening of the nozzle is carried out when the ink cavity is at an established pressure and thus allows a stable and rapid starting of the jet.
  • Air entrapment in the cavity at the time of stopping is avoided and the phenomenon of air / ink spraying is eliminated when the jet is started.
  • this solution has a serious drawback because of the bulk caused by the housing on the one hand of the jet stimulation actuator and, on the other hand, of the shutter assembly.
  • the cavity upstream of the nozzle must receive these two functions either coaxially, or along two distinct axes converging towards the nozzle.
  • the device according to the invention has the advantage of being compact. It ensures correct sealing of the nozzle while guaranteeing correct and repetitive jet stops and starts.
  • An additional advantage lies in the reduced number of parts required for its implementation.
  • the deformable member comprises a part located between the stimulation means and the nozzle, this part being connected to a bellows allowing relative movement of said part relative to the nozzle, the bellows, subjected on one of its faces to the pressure of the material in the cavity, having mechanical characteristics such that for a pressure of the material not allowing the emission of 'a jet said part of the deformable member closes the nozzle, and that for a pressure of the material allowing the emission of a jet said part of the deformable member is spaced from the nozzle.
  • the stimulation means may comprise an elongated body, the bellows surrounding the elongated body and being tightly fixed to this elongated body so that the space between the elongated body, the bellows and the part of the deformable member contains a gas.
  • This gas can simply be air.
  • the control means can, according to another variant, comprise an actuator acting on the deformable member to close or release the nozzle.
  • This actuator can also serve as means for stimulating the jet.
  • the actuator can advantageously be a piezoelectric or electromagnetic element comprising means for receiving a continuous electric voltage in order to force the deformable member to release the nozzle and an alternating voltage making it possible to stimulate the jet.
  • the nozzle can be contained in a nozzle plate
  • the deformable member can be a membrane held in the device by its periphery
  • the nozzle plate, the membrane and the actuator forming a succession of elements stacked and centered on the nozzle, the nozzle plate having one of these main faces in contact with a supply duct for said material and the other of its main faces adjacent to the membrane, communication being provided between the two main faces of the nozzle plate for the passage of said material.
  • the device comprises a support 1 which is intended to be fixed to the mechanical structure of the print head (see FIG. 1 of the document FR-A-2 653 063).
  • the support 1 has a tubular part 4 whose axis coincides with the axis of the ink jet.
  • the body 2 of the barrel 3 which is a generally cylindrical part, with an axis of revolution coincident with the axis of the tubular part 4.
  • the barrel 3 is drilled right through an axial hole 8.
  • the body 2 constitutes the lower part of the barrel 3.
  • a shoulder 5 constitutes the separation between the body 2 and the upper part of the barrel 3.
  • the body 2 is provided with an upper groove 6 near the shoulder 5 and a lower groove 7.
  • the lower end 9 of the body 2 is threaded to receive the nut 10.
  • Radial holes 11, 12 drilled respectively in the grooves 6 and 7 provide communication between the axial hole 8 and the grooves 6 and 7.
  • the body 2 Before engaging the barrel body 2 in the tubular part 4 of the support 1, the body 2 is successively threaded: the ring-shaped seal 13, the tubular spacer 14 and the seal 15 also in the shape of a ring.
  • the average diameters of the seals 13 and 15 correspond to the diameter of the spacer 14. This means that the seal 13, the spacer 14 and the seal 15 constitute a stack.
  • the gasket 13 abuts on the shoulder 5 of the barrel and the force exerted by the nut 10, during screwing, on the gasket 15 is reflected on the gasket 13 through the spacer 14.
  • the seals 13 and 15 are seals which are expandable under the effect of a force.
  • the tightening of the nut 10 therefore causes the application of the seals 13 and 15 on the internal wall of the tubular part 4, thus ensuring both the seal at the seals and the fixing of the barrel 3 on the support 1.
  • the nut 10 does not come to bear on the tubular part 4 of the support. Its action is exerted only on the seal 13 - spacer 14 - seal 15 stack.
  • the spacer 14 is provided with an upper groove 16 and a lower groove 17. Holes 18 and 19 are drilled radially and respectively in the grooves 16 and 17. During assembly, the grooves 16 and 17 of the spacer 14 are located opposite the grooves 6 and 7, respectively, of the body 2.
  • the support 4 is provided with a connector 21 for introducing pressurized ink into the tubular part 4 and with a connector 22 allowing the same tubular part to be purged. These connections 21 and 22 open near the grooves 16 and 17 respectively of the spacer 14.
  • the resonator 25, making it possible to stimulate the ink jet, is introduced by its end 24 into the barrel 3 through the upper orifice of the hole 8, through the seal 20.
  • the other end of the resonator is extended by an electric cable 23 to an external control member.
  • the cable 23 passes through the axial hole 27 of the flange 28.
  • the resonator is fixed in the barrel as follows.
  • the resonator 25 fitted with the seal 20 is pressed into the hole 8 until the underside of the seal 20 abuts on a shoulder provided in the hole 8.
  • a flange 26 of the resonator then comes into abutment on the upper face of the joint 20.
  • the flange is slid along the cable 23 and its threaded lower part 29 is screwed into the tapped upper part of the hole 8 until the seal 20 is pressed.
  • the device operates as follows.
  • the pressurized ink injected through the connector 21 bathes the outside of the spacer 14 and penetrates inside through the holes 18 to reach the external part of the body 2 of the barrel.
  • the ink passes through the holes 11 of the groove 6, penetrates inside the barrel by bathing the resonator 25 and goes towards the end 9 of the barrel which is terminated by a washer (not visible in FIG. 1) pierced an axial hole serving as an ink emission nozzle.
  • the device is purged by return of the ink, thanks to the holes 12, in the tubular space between the body 2 and the spacer 14 then, thanks to the holes 19 of the spacer, in the tubular space included between the spacer 14 and the tubular part of the support.
  • the ink is then discharged through the connector 22.
  • the inkjet stimulated by the resonator 25, is therefore made along the axis of the device as shown by the arrow drawn under the nut 10.
  • FIG. 2 represents a barrel 103 of a modulation device in which is housed a modulator 125, these elements being of the type shown in FIG. 1.
  • the modulator 125 rests on an internal shoulder of the barrel 103 by means of the collar 126 with interposition of a seal 120. It has an end portion 130 of smaller diameter than the rest of the modulator, which leads to the presence of a shoulder 131.
  • a collar 132 connects the end portion 130 to the rest of the modulator.
  • a cavity 140 constituting a part of the axial hole 108 of the barrel and in which ink can flow through the hole 111 and which can be evacuated through the hole 112.
  • the ink is subjected to the action of resonator 125.
  • a plate 141 in the form of a disc and provided with a central hole 142 forming the nozzle.
  • the nozzle 142 is located opposite the lower end 124 of the resonator 125.
  • a deformable member 150 is placed between the resonator 125 and the nozzle 142.
  • the deformable member 150 comprises a portion 151 in the form of a disc, of diameter corresponding to the diameter of the end portion 130 of the resonator, a annular part 152 for connection to the resonator and a part intermediate 153 acting as a bellows and surrounding the end portion 130 of the resonator.
  • the collar 132 of the resonator makes it possible to easily center the deformable member 150 on the end portion 130.
  • This deformable member can be made of stainless steel and be fixed by sealed welding to the resonator. A volume of air is therefore trapped between the deformable member 150 and the end portion 130 of the resonator.
  • a washer may use a coating, for example of fluoropolymer, on the external side of this part 151.
  • the nozzle shutter is of the passive type. It is actuated by the different pressures established in the barrel during the stop and start phases.
  • the bellows 153 has a useful stroke which allows bistable operation of the shutter. During a first state, the prestressed bellows rests on the plate 141, which causes the nozzle to be blocked.
  • the bellows 153 compresses under the effect of the pressure increase of the ink in the cavity 140 until the part 151 of the deformable member comes to bear against the end 124 of the resonator. This is the start-up phase.
  • the nozzle 142 is released and the ink can be emitted in the form of a jet.
  • the bellows can be produced from a sheet of stainless steel 20 ⁇ m thick.
  • FIG. 3 Another variant of an ink jet modulation device is shown in FIG. 3.
  • This device is fixed to an ink jet printing machine by means of a flange 50 and comprises a cylindrical body 51 screwed to this flange.
  • the device can be fixed to the machine by the cylindrical body 51.
  • a nozzle plate 60 in the form of a disc, obtained for example by chemical cutting and etching is disposed in a housing of suitable shape, provided in the bottom 53 of the body 51.
  • the bottom 53 is pierced with a central hole 52 and comprises an annular ink supply duct 54 communicating with a circuit ink equipped with pressure and purge valves not shown.
  • the nozzle plate 60 has an annular conduit 61 directed upwards and is pierced with a central hole 62 forming an ejection nozzle as well as holes 63 (only one is visible in the figure) making the annular conduits 54 and 61 communicate
  • the volume constituted by the conduits 54 and 61 and by the communication holes 63 forms the equivalent of a cavity.
  • the nozzle plate 60 is covered by a metal membrane 55 acting as a shutter, a flexible film 56 (made of elastomer for example) being interposed between the membrane 55 and the nozzle plate 60 to ensure sealing.
  • the membrane 55 and the flexible film 56 are disc-shaped elements held at their periphery by the tightening resulting from the screwing of the body 51 on the flange 50.
  • a piezoelectric actuator 70 is made integral with the membrane 55 and receives electrical control signals by virtue of the electrical cable 71.
  • an electromagnetic actuator could be used.
  • the operation of the device represented in FIG. 3 is identical to the device of FIG. 2.
  • the stiffness of the assembly ensures the two stable positions at the defined pressure values.
  • a DC voltage can be supplied to the actuator 70 to allow the lifting of the membrane 55 and of the flexible sealing film 56 which adheres thereto, thus freeing the nozzle to cause the emission of an ink jet.
  • the application of this DC voltage makes it possible to obtain more frank pressure transients.
  • the DC voltage can be positive or negative to help open or close the nozzle.
  • An alternating voltage to which the direct voltage is possibly superimposed makes the membrane vibrate 55 and divide the inkjet into a succession of drops.
  • the continuous tension offers the possibility of modifying the flow of the ink thanks to a modification of the value of the tension. This regulates the speed of the jet.
  • This arrangement has the advantage of compactness while limiting the number of parts for performing the function.

Abstract

The assembly for providing a jet of liquid under pressure includes a nozzle (142) which is able to communicate with a cavity (140) through which the material passes. The cavity is the position at which the liquid is put under pressure in order to form a controlled jet, and includes a stimulation element (125) situated near to the nozzle to divide the jet into a series of elements. A device is provided to close the nozzle in the absence of jet emission. This comprises a deformable element (150) placed between the stimulation element (125) and the nozzle. This is arranged to close the nozzle when the control does not permit the emission of a jet, and open it when the jet is produced. The deformable element is able to adopt one of two bi-stable positions, according to the pressure prevailing within the pressurising cavity (140).

Description

La présente invention concerne un dispositif permettant l'émission d'un jet stimulé de matière sous pression par une buse obturable. Un tel dispositif est utilisable en particulier pour réaliser des têtes d'impression d'imprimante à jet d'encre.The present invention relates to a device allowing the emission of a stimulated jet of material under pressure by a closable nozzle. Such a device can be used in particular for producing ink jet printer printheads.

En effet, les imprimantes à jet d'encre, comme leur nom l'indique, génèrent des jets ou gouttes d'encre à l'aide de buses d'éjection. Le pilotage de la pression d'encre en amont de la buse permet de démarrer ou d'arrêter l'écoulement du fluide à travers l'orifice de la buse. La qualité des arrêts et démarrages dépend essentiellement de la durée des transitoires de pression pendant ces phases. Une transition franche des valeurs de pression permet d'obtenir une bonne directivité du jet au démarrage et évite la formation d'un dépôt d'encre en sortie de buse au moment de l'arrêt du jet.Indeed, inkjet printers, as their name suggests, generate jets or drops of ink using ejection nozzles. The control of the ink pressure upstream of the nozzle makes it possible to start or stop the flow of the fluid through the orifice of the nozzle. The quality of stops and starts essentially depends on the duration of the pressure transients during these phases. A clear transition in pressure values makes it possible to obtain good directivity of the jet at start-up and prevents the formation of an ink deposit at the outlet of the nozzle when the jet stops.

Le passage du mode arrêt au mode impression pose quelques problèmes, à savoir :

  • la répétitivité des phases transitoires qui est difficile à obtenir avec les moyens classiques de pilotage sur le circuit pression que constituent les électrovannes ;
  • l'écoulement du fluide par la buse après l'arrêt perturbe la stabilisation rapide du jet : lorsque la température ambiante évolue, l'encre résidant entre la buse et l'électrovanne peut se dilater et provoquer un écoulement de fluide par la buse qui perturbera le redémarrage du jet ;
  • l'utilisation d'encres à séchage rapide conduit au colmatage de la buse à la suite d'un arrêt prolongé.
The transition from stop mode to print mode poses some problems, namely:
  • the repeatability of the transient phases which is difficult to obtain with conventional means of piloting on the pressure circuit constituted by the solenoid valves;
  • the flow of fluid through the nozzle after stopping disrupts the rapid stabilization of the jet: when the ambient temperature changes, the ink residing between the nozzle and the solenoid valve may expand and cause a flow of fluid through the nozzle which will disturb restarting the jet;
  • the use of quick-drying inks leads to clogging of the nozzle after prolonged stoppage.

Différentes solutions ont été proposées pour pallier ces défauts. Une de ces solutions consiste à obturer la buse entre deux phases de fonctionnement.Different solutions have been proposed to overcome these shortcomings. One of these solutions consists in sealing the nozzle between two operating phases.

On peut résumer les solutions proposées pour pallier les risques de colmatage des buses en mentionnant les documents suivants.We can summarize the solutions proposed to mitigate the risks of clogging of the nozzles by mentioning the following documents.

Le document EP-A-54 905 divulgue l'utilisation d'un moyen de fermeture électromagnétique de la buse d'émission de jet pour éviter que l'air ambiant n'y pénètre et s'applique au cas où l'encre d'impression est un fluide magnétique. On explique notamment comment les problèmes du circuit d'alimentation pour un fluide magnétique sont résolus.Document EP-A-54 905 discloses the use of an electromagnetic closure means of the jet emission nozzle to prevent ambient air from entering it and applies to the case where the ink of impression is a magnetic fluid. We explain in particular how the problems of the supply circuit for a magnetic fluid are solved.

Le brevet US-A-4 199 767 décrit un moyen d'obturation de buse constitué par une plaque pouvant se déplacer devant la buse grâce à un champ magnétique. Une idée similaire est présentée dans IBM Technical Disclosure Bulletin, vol. 18, n° 12, Mai 1976. Dans les systèmes proposés, qui mettent en contact deux parties solides pour obturer un orifice, il est cependant nécessaire de prévoir des forces électromagnétiques suffisantes pour décoller les contacts à la suite d'un arrêt prolongé, un résidu d'encre aux alentours de ces contacts ayant pu sécher.US-A-4 199 767 describes a nozzle closure means constituted by a plate which can move in front of the nozzle by a magnetic field. A similar idea is presented in IBM Technical Disclosure Bulletin, vol. 18, n ° 12, May 1976. In the systems proposed, which bring two solid parts into contact to close an orifice, it is however necessary to provide sufficient electromagnetic forces to detach the contacts following a prolonged stop, a ink residue around these contacts that may have dried.

Le document FR-A-2 540 044 décrit une solution d'obturation de buse à l'aide d'électrovannes équipées d'une partie souple montée sur la tige d'un élément de translation. Cette fonction est utilisée pour générer des gouttes à la fréquence des ouvertures et fermetures de la buse. Cette solution est reprise dans le document WO 91/00808 dans le cas d'une utilisation en technologie de jet continu dévié. Dans ce cas, l'élément de translation à commande électromagnétique vient en appui sur la buse par l'intermédiaire d'une partie souple et isole l'encre du milieu ambiant pendant les arrêts. Cette solution évite l'écoulement de l'encre et le séchage de celle-ci en sortie de buse. De plus, l'ouverture de la buse est réalisée lorsque la cavité d'encre se trouve en pression établie et permet ainsi un démarrage stable et rapide du jet. L'emprisonnement d'air dans la cavité au moment de l'arrêt est évité et on supprime le phénomène de pulvérisation air/encre au moment du démarrage du jet. Par contre, cette solution présente un inconvénient sérieux à cause de l'encombrement occasionné par le logement d'une part de l'actuateur de stimulation de jet et, d'autre part, de l'ensemble obturateur. La cavité en amont de la buse doit recevoir ces deux fonctions soit de façon coaxiale, soit selon deux axes distincts convergents vers la buse.The document FR-A-2 540 044 describes a solution for closing the nozzle using solenoid valves fitted with a flexible part mounted on the rod of a translation element. This function is used to generate drops at the frequency of nozzle openings and closings. This solution is taken up in document WO 91/00808 in the case of use in deviated continuous jet technology. In this case, the electromagnetically controlled translation element bears on the nozzle by means of a flexible part and isolates the ink from the ambient environment during stops. This solution prevents the ink from flowing and drying out of the nozzle. Furthermore, the opening of the nozzle is carried out when the ink cavity is at an established pressure and thus allows a stable and rapid starting of the jet. Air entrapment in the cavity at the time of stopping is avoided and the phenomenon of air / ink spraying is eliminated when the jet is started. On the other hand, this solution has a serious drawback because of the bulk caused by the housing on the one hand of the jet stimulation actuator and, on the other hand, of the shutter assembly. The cavity upstream of the nozzle must receive these two functions either coaxially, or along two distinct axes converging towards the nozzle.

Pour remédier aux inconvénients que présentent ces dispositifs de l'art antérieur, il est proposé selon la présente invention la mise en place d'un obturateur de buse qui possède la particularité d'être associé à la fonction stimulation du dispositif. Le dispositif selon l'invention a l'avantage d'être compact. Il assure l'obturation correcte de la buse tout en garantissant des arrêts et démarrages de jets corrects et répétitifs. Un avantage supplémentaire réside dans le nombre réduit de pièces nécessaires à sa mise en oeuvre.To remedy the drawbacks which these devices of the prior art present, it is proposed according to the present invention the installation of a nozzle shutter which has the particularity of being associated with the stimulation function of the device. The device according to the invention has the advantage of being compact. It ensures correct sealing of the nozzle while guaranteeing correct and repetitive jet stops and starts. An additional advantage lies in the reduced number of parts required for its implementation.

L'invention a donc pour objet un dispositif permettant l'émission de matière sous forme d'un jet par l'intermédiaire d'une buse comportant au moins un orifice d'émission, la buse pouvant communiquer avec une cavité du dispositif par où transite ladite matière et où elle est mise en pression pour permettre la formation dudit jet sous l'effet de moyens de commande, des moyens de stimulation étant situés à proximité de la buse pour fractionner le jet en une succession d'éléments, des moyens d'obturation de la buse en l'absence d'émission d'un jet de matière étant prévus, caractérisé en ce que les moyens d'obturation sont constitués par un organe déformable, placé entre les moyens de stimulation et la buse et solidaire des moyens de stimulation, l'organe déformable étant conçu mécaniquement en fonction de la pression à laquelle est soumise ladite matière pour posséder le fonctionnement bistable suivant :

  • être dans une position d'obturation de la buse lorsque les moyens de commande n'autorisent pas l'émission d'un jet de matière,
  • être dans une position de libération de la buse lorsque les moyens de commande autorisent l'émission d'un jet de matière.
The subject of the invention is therefore a device allowing the emission of material in the form of a jet via a nozzle comprising at least one emission orifice, the nozzle being able to communicate with a cavity of the device through which transits said material and where it is pressurized to allow the formation of said jet under the effect of control means, stimulation means being located near the nozzle to split the jet into a succession of elements, means for obturation of the nozzle in the absence of emission of a jet of material being provided, characterized in that the obturation means consist of a deformable member, placed between the stimulation means and the nozzle and integral with the stimulation means, the deformable member being designed mechanically as a function of the pressure to which said material is subjected in order to have the following bistable operation:
  • be in a closed position of the nozzle when the control means do not allow the emission of a jet of material,
  • be in a position for releasing the nozzle when the control means authorize the emission of a jet of material.

Dans le cas où l'émission d'un jet est commandée par la pression existant dans la cavité, l'organe déformable comprend une partie se trouvant entre les moyens de stimulation et la buse, cette partie étant reliée à un soufflet autorisant un déplacement relatif de ladite partie par rapport à la buse, le soufflet, soumis sur l'une de ses faces à la pression de la matière dans la cavité, possédant des caractéristiques mécaniques telles que pour une pression de la matière n'autorisant pas l'émission d'un jet ladite partie de l'organe déformable obture la buse, et que pour une pression de la matière autorisant l'émission d'un jet ladite partie de l'organe déformable est écartée de la buse.In the case where the emission of a jet is controlled by the pressure existing in the cavity, the deformable member comprises a part located between the stimulation means and the nozzle, this part being connected to a bellows allowing relative movement of said part relative to the nozzle, the bellows, subjected on one of its faces to the pressure of the material in the cavity, having mechanical characteristics such that for a pressure of the material not allowing the emission of 'a jet said part of the deformable member closes the nozzle, and that for a pressure of the material allowing the emission of a jet said part of the deformable member is spaced from the nozzle.

Les moyens de stimulation peuvent comporter un corps allongé, le soufflet entourant le corps allongé et étant fixé de manière étanche à ce corps allongé de façon que l'espace compris entre le corps allongé, le soufflet et la partie de l'organe déformable renferme un gaz. Ce gaz peut simplement être de l'air.The stimulation means may comprise an elongated body, the bellows surrounding the elongated body and being tightly fixed to this elongated body so that the space between the elongated body, the bellows and the part of the deformable member contains a gas. This gas can simply be air.

Avantageusement, lorsque l'émission d'un jet n'est pas autorisée, ladite partie de l'organe déformable est plaquée sur la buse, des moyens d'étanchéité étant prévus entre ladite partie et la buse.Advantageously, when the emission of a jet is not authorized, said part of the deformable member is pressed against the nozzle, sealing means being provided between said part and the nozzle.

Les moyens de commande peuvent, selon une autre variante, comprendre un actionneur agissant sur l'organe déformable pour obturer ou libérer la buse. Cet actionneur peut également servir de moyens de stimulation du jet.The control means can, according to another variant, comprise an actuator acting on the deformable member to close or release the nozzle. This actuator can also serve as means for stimulating the jet.

L'actionneur peut avantageusement être un élément piézo-électrique ou électromagnétique comprenant des moyens pour recevoir une tension électrique continue afin de forcer l'organe déformable à libérer la buse et une tension alternative permettant de stimuler le jet.The actuator can advantageously be a piezoelectric or electromagnetic element comprising means for receiving a continuous electric voltage in order to force the deformable member to release the nozzle and an alternating voltage making it possible to stimulate the jet.

Selon un mode de réalisation préféré de cette variante, la buse peut être contenue dans une plaque à buse, l'organe déformable peut être une membrane maintenue dans le dispositif par sa périphérie, la plaque à buse, la membrane et l'actionneur formant une succession d'éléments empilés et centrés sur la buse, la plaque à buse possédant l'une de ces faces principales en contact avec un conduit d'amenée de ladite matière et l'autre de ses faces principales adjacente à la membrane, une communication étant prévue entre les deux faces principales de la plaque à buse pour le passage de ladite matière.According to a preferred embodiment of this variant, the nozzle can be contained in a nozzle plate, the deformable member can be a membrane held in the device by its periphery, the nozzle plate, the membrane and the actuator forming a succession of elements stacked and centered on the nozzle, the nozzle plate having one of these main faces in contact with a supply duct for said material and the other of its main faces adjacent to the membrane, communication being provided between the two main faces of the nozzle plate for the passage of said material.

L'invention va être maintenant décrite en prenant pour exemple d'application une tête d'impression d'imprimante à jet d'encre bien qu'elle puisse s'appliquer à l'émission d'un jet stimulé d'une autre matière. L'invention sera mieux comprise au moyen des dessins annexés parmi lesquels :

  • la figure 1 représente, en vue éclatée, un dispositif de stimulation ou de modulation pour tête d'impression à jet d'encre selon l'art connu,
  • la figure 2 représente, vu en coupe longitudinale, le canon du dispositif de modulation équipé de son résonateur et où est mise en oeuvre la présente invention,
  • la figure 3 représente un élément d'une autre variante de dispositif de modulation mettant en oeuvre la présente invention.
The invention will now be described by taking the example of an inkjet printer printhead, although it can be applied to the emission of a stimulated jet of another material. The invention will be better understood by means of the appended drawings in which:
  • FIG. 1 represents, in exploded view, a stimulation or modulation device for an ink jet print head according to the known art,
  • FIG. 2 represents, seen in longitudinal section, the barrel of the modulation device equipped with its resonator and where the present invention is implemented,
  • FIG. 3 represents an element of another variant of a modulation device implementing the present invention.

La solution proposée par l'invention va maintenant être appliquée au dispositif de modulation divulgué par le document FR-A-2 653 063. Ce dispositif est représenté en vue éclatée à la figure 1, les éléments représentés à la partie droite de la figure se situant normalement dans le prolongement de la partie gauche supérieure.The solution proposed by the invention will now be applied to the modulation device disclosed in document FR-A-2 653 063. This device is shown in exploded view in FIG. 1, the elements represented on the right side of the figure are normally located in the extension of the upper left part.

Le dispositif comporte un support 1 qui est destiné à être fixé sur la structure mécanique de la tête d'impression (voir la figure 1 du document FR-A-2 653 063). Le support 1 possède une partie tubulaire 4 d'axe confondu avec l'axe du jet d'encre. Dans cette partie tubulaire 4 vient se loger le corps 2 du canon 3 qui est une pièce de forme générale cylindrique, d'axe de révolution confondu avec l'axe de la partie tubulaire 4. Le canon 3 est percé de part en part d'un trou axial 8.The device comprises a support 1 which is intended to be fixed to the mechanical structure of the print head (see FIG. 1 of the document FR-A-2 653 063). The support 1 has a tubular part 4 whose axis coincides with the axis of the ink jet. In this tubular part 4 is housed the body 2 of the barrel 3 which is a generally cylindrical part, with an axis of revolution coincident with the axis of the tubular part 4. The barrel 3 is drilled right through an axial hole 8.

Le corps 2 constitue la partie inférieure du canon 3. Un épaulement 5 constitue la séparation entre le corps 2 et la partie supérieure du canon 3. Le corps 2 est pourvu d'une gorge supérieure 6 près de l'épaulement 5 et d'une gorge inférieure 7. L'extrémité inférieure 9 du corps 2 est filetée pour recevoir l'écrou 10. Des trous radiaux 11, 12 percés respectivement dans les gorges 6 et 7 assurent la communication entre le trou axial 8 et les gorges 6 et 7.The body 2 constitutes the lower part of the barrel 3. A shoulder 5 constitutes the separation between the body 2 and the upper part of the barrel 3. The body 2 is provided with an upper groove 6 near the shoulder 5 and a lower groove 7. The lower end 9 of the body 2 is threaded to receive the nut 10. Radial holes 11, 12 drilled respectively in the grooves 6 and 7 provide communication between the axial hole 8 and the grooves 6 and 7.

Avant d'engager le corps 2 du canon dans la partie tubulaire 4 du support 1, on enfile successivement sur le corps 2 : le joint 13 en forme de bague, l'entretoise tubulaire 14 et le joint 15 également en forme de bague. Les diamètres moyens des joints 13 et 15 correspondent au diamètre de l'entretoise 14. Ceci fait que le joint 13, l'entretoise 14 et le joint 15 constituent un empilement.Before engaging the barrel body 2 in the tubular part 4 of the support 1, the body 2 is successively threaded: the ring-shaped seal 13, the tubular spacer 14 and the seal 15 also in the shape of a ring. The average diameters of the seals 13 and 15 correspond to the diameter of the spacer 14. This means that the seal 13, the spacer 14 and the seal 15 constitute a stack.

Le corps 2 du canon 3, équipé du joint 13, de l'entretoise 14 et du joint 15, étant introduit dans la partie tubulaire 4, on visse l'écrou 10 sur l'extrémité 9 du corps 2 par l'orifice inférieur de la partie tubulaire 4. Le joint 13 vient en butée sur l'épaulement 5 du canon et la force exercée par l'écrou 10, en cours de vissage, sur le joint 15 se répercute sur le joint 13 par l'intermédiaire de l'entretoise 14. Les joints 13 et 15 sont des joints expansibles sous l'effet d'une force. Le serrage de l'écrou 10 provoque donc l'application des joints 13 et 15 sur la paroi interne de la partie tubulaire 4, assurant ainsi à la fois l'étanchéité au niveau des joints et la fixation du canon 3 sur le support 1. Il faut remarquer que l'écrou 10 ne vient pas en appui sur la partie tubulaire 4 du support. Son action ne s'exerce que sur l'empilement joint 13 - entretoise 14 - joint 15.The body 2 of the barrel 3, fitted with the gasket 13, the spacer 14 and the gasket 15, being introduced into the tubular part 4, the nut 10 is screwed onto the end 9 of the body 2 through the lower orifice the tubular part 4. The gasket 13 abuts on the shoulder 5 of the barrel and the force exerted by the nut 10, during screwing, on the gasket 15 is reflected on the gasket 13 through the spacer 14. The seals 13 and 15 are seals which are expandable under the effect of a force. The tightening of the nut 10 therefore causes the application of the seals 13 and 15 on the internal wall of the tubular part 4, thus ensuring both the seal at the seals and the fixing of the barrel 3 on the support 1. It should be noted that the nut 10 does not come to bear on the tubular part 4 of the support. Its action is exerted only on the seal 13 - spacer 14 - seal 15 stack.

L'entretoise 14 est pourvue d'une gorge supérieure 16 et d'une gorge inférieure 17. Des trous 18 et 19 sont percés radialement et respectivement dans les gorges 16 et 17. Au montage, les gorges 16 et 17 de l'entretoise 14 se trouvent en vis-à-vis des gorges 6 et 7, respectivement, du corps 2.The spacer 14 is provided with an upper groove 16 and a lower groove 17. Holes 18 and 19 are drilled radially and respectively in the grooves 16 and 17. During assembly, the grooves 16 and 17 of the spacer 14 are located opposite the grooves 6 and 7, respectively, of the body 2.

Le support 4 est pourvu d'un raccord 21 d'introduction d'encre sous pression dans la partie tubulaire 4 et d'un raccord 22 permettant la purge de cette même partie tubulaire. Ces raccords 21 et 22 débouchent à proximité des gorges respectivement 16 et 17 de l'entretoise 14.The support 4 is provided with a connector 21 for introducing pressurized ink into the tubular part 4 and with a connector 22 allowing the same tubular part to be purged. These connections 21 and 22 open near the grooves 16 and 17 respectively of the spacer 14.

Le résonateur 25, permettant de stimuler le jet d'encre, est introduit par son extrémité 24 dans le canon 3 par l'orifice supérieur du trou 8, au travers du joint 20. L'autre extrémité du résonateur se prolonge par un câble électrique 23 vers un organe de commande extérieur. Le câble 23 passe dans le trou axial 27 de la bride 28.The resonator 25, making it possible to stimulate the ink jet, is introduced by its end 24 into the barrel 3 through the upper orifice of the hole 8, through the seal 20. The other end of the resonator is extended by an electric cable 23 to an external control member. The cable 23 passes through the axial hole 27 of the flange 28.

La fixation du résonateur dans le canon se fait de la façon suivante. Le résonateur 25 équipé du joint 20 est enfoncé dans le trou 8 jusqu'à ce que la face inférieure du joint 20 arrive en butée sur un épaulement prévu dans le trou 8. Une collerette 26 du résonateur vient alors en butée sur la face supérieure du joint 20. La bride est glissée le long du câble 23 et sa partie inférieure filetée 29 se visse dans la partie supérieure taraudée du trou 8 jusqu'à venir presser le joint d'étanchéité 20.The resonator is fixed in the barrel as follows. The resonator 25 fitted with the seal 20 is pressed into the hole 8 until the underside of the seal 20 abuts on a shoulder provided in the hole 8. A flange 26 of the resonator then comes into abutment on the upper face of the joint 20. The flange is slid along the cable 23 and its threaded lower part 29 is screwed into the tapped upper part of the hole 8 until the seal 20 is pressed.

Le fonctionnement du dispositif s'effectue comme suit. L'encre sous pression injectée par le raccord 21 baigne l'extérieur de l'entretoise 14 et pénètre à l'intérieur par les trous 18 pour atteindre la partie externe du corps 2 du canon. L'encre passe dans les trous 11 de la gorge 6, pénètre à l'intérieur du canon en baignant le résonateur 25 et se dirige vers l'extrémité 9 du canon qui est terminée par une rondelle (non visible sur la figure 1) percée d'un trou axial servant de buse d'émission d'encre. La purge du dispositif se fait par retour de l'encre, grâce aux trous 12, dans l'espace tubulaire compris entre le corps 2 et l'entretoise 14 puis, grâce aux trous 19 de l'entretoise, dans l'espace tubulaire compris entre l'entretoise 14 et la partie tubulaire du support. L'encre est ensuite évacuée par le raccord 22.The device operates as follows. The pressurized ink injected through the connector 21 bathes the outside of the spacer 14 and penetrates inside through the holes 18 to reach the external part of the body 2 of the barrel. The ink passes through the holes 11 of the groove 6, penetrates inside the barrel by bathing the resonator 25 and goes towards the end 9 of the barrel which is terminated by a washer (not visible in FIG. 1) pierced an axial hole serving as an ink emission nozzle. The device is purged by return of the ink, thanks to the holes 12, in the tubular space between the body 2 and the spacer 14 then, thanks to the holes 19 of the spacer, in the tubular space included between the spacer 14 and the tubular part of the support. The ink is then discharged through the connector 22.

Le jet d'encre stimulé par le résonateur 25, se fait donc selon l'axe du dispositif ainsi que le figure la flèche dessinée sous l'écrou 10.The inkjet stimulated by the resonator 25, is therefore made along the axis of the device as shown by the arrow drawn under the nut 10.

Des trous latéraux prévus dans l'écrou 10, le canon 3 et la bride 28 permettent d'effectuer des réglages pour obtenir le bon alignement du jet d'encre. Ces réglages sont expliqués dans le document FR-A-2 653 063.Side holes provided in the nut 10, the barrel 3 and the flange 28 allow adjustments to be made to obtain the correct alignment of the ink jet. These settings are explained in document FR-A-2 653 063.

La figure 2 représente un canon 103 de dispositif de modulation dans lequel est logé un modulateur 125, ces éléments étant du type représenté à la figure 1. Le modulateur 125 repose sur un épaulement interne du canon 103 grâce à la collerette 126 avec interposition d'un joint d'étanchéité 120. Il comporte une partie d'extrémité 130 de diamètre plus petit que le reste du modulateur, ce qui conduit à la présence d'un épaulement 131. Un collet 132 relie la partie d'extrémité 130 au reste du modulateur.FIG. 2 represents a barrel 103 of a modulation device in which is housed a modulator 125, these elements being of the type shown in FIG. 1. The modulator 125 rests on an internal shoulder of the barrel 103 by means of the collar 126 with interposition of a seal 120. It has an end portion 130 of smaller diameter than the rest of the modulator, which leads to the presence of a shoulder 131. A collar 132 connects the end portion 130 to the rest of the modulator.

Entre le résonateur 125 et le canon 103 existe une cavité 140 constituant une partie du trou axial 108 du canon et dans laquelle peut circuler de l'encre introduite par le trou 111 et pouvant être évacuée par le trou 112. Dans la cavité 140, l'encre est soumise à l'action du résonateur 125.Between the resonator 125 and the barrel 103 there is a cavity 140 constituting a part of the axial hole 108 of the barrel and in which ink can flow through the hole 111 and which can be evacuated through the hole 112. In the cavity 140, the ink is subjected to the action of resonator 125.

A l'extrémité inférieure du canon 103 est fixée une plaque 141 en forme de disque et pourvue d'un trou central 142 formant la buse. La buse 142 se trouve en vis-à-vis de l'extrémité inférieure 124 du résonateur 125.At the lower end of the barrel 103 is fixed a plate 141 in the form of a disc and provided with a central hole 142 forming the nozzle. The nozzle 142 is located opposite the lower end 124 of the resonator 125.

Selon l'invention, un organe déformable 150 est placé entre le résonateur 125 et la buse 142. L'organe déformable 150 comporte une partie 151 en forme de disque, de diamètre correspondant au diamètre de la partie d'extrémité 130 du résonateur, une partie annulaire 152 de liaison au résonateur et une partie intermédiaire 153 jouant le rôle de soufflet et entourant la partie d'extrémité 130 du résonateur.According to the invention, a deformable member 150 is placed between the resonator 125 and the nozzle 142. The deformable member 150 comprises a portion 151 in the form of a disc, of diameter corresponding to the diameter of the end portion 130 of the resonator, a annular part 152 for connection to the resonator and a part intermediate 153 acting as a bellows and surrounding the end portion 130 of the resonator.

Le collet 132 du résonateur permet de centrer aisément l'organe déformable 150 sur la partie d'extrémité 130. Cet organe déformable peut être en acier inoxydable et être fixé par soudure étanche sur le résonateur. Un volume d'air est donc emprisonné entre l'organe déformable 150 et la partie d'extrémité 130 du résonateur.The collar 132 of the resonator makes it possible to easily center the deformable member 150 on the end portion 130. This deformable member can be made of stainless steel and be fixed by sealed welding to the resonator. A volume of air is therefore trapped between the deformable member 150 and the end portion 130 of the resonator.

Une rondelle d'étanchéité 161 en élastomère ou en Téflon®, fixée sur le côté externe de la partie 151 en forme de disque, constitue une interface souple entre l'organe déformable et la plaque 141. A la place d'une rondelle, on peut mettre en oeuvre un revêtement, par exemple de polymère fluoré, sur le côté externe de cette partie 151.A sealing washer 161 made of elastomer or Teflon®, fixed to the external side of the disc-shaped part 151, constitutes a flexible interface between the deformable member and the plate 141. In place of a washer, may use a coating, for example of fluoropolymer, on the external side of this part 151.

Dans l'exemple d'application représenté à la figure 2, l'obturateur de buse est du type passif. Il est actionné grâce aux différentes pressions établies dans le canon lors des phases d'arrêt et de démarrage. Le soufflet 153 possède une course utile qui permet un fonctionnement bistable de l'obturateur. Lors d'un premier état, le soufflet précontraint repose sur la plaque 141, ce qui provoque l'obturation de la buse.In the application example shown in Figure 2, the nozzle shutter is of the passive type. It is actuated by the different pressures established in the barrel during the stop and start phases. The bellows 153 has a useful stroke which allows bistable operation of the shutter. During a first state, the prestressed bellows rests on the plate 141, which causes the nozzle to be blocked.

Lors d'un deuxième état, le soufflet 153 se comprime sous l'effet de la montée en pression de l'encre dans la cavité 140 jusqu'à ce que la partie 151 de l'organe déformable vienne en appui contre l'extrémité 124 du résonateur. C'est la phase de démarrage. La buse 142 est libérée et l'encre peut être émise sous forme d'un jet.During a second state, the bellows 153 compresses under the effect of the pressure increase of the ink in the cavity 140 until the part 151 of the deformable member comes to bear against the end 124 of the resonator. This is the start-up phase. The nozzle 142 is released and the ink can be emitted in the form of a jet.

Cette disposition permet le démarrage et l'arrêt du jet à des valeurs de pression maîtrisées en agissant sur les paramètres suivants : raideur mécanique du soufflet, valeur de la précontrainte de fermeture, surface effective du soufflet. A titre d'exemple, le soufflet peut être réalisé à partir d'une feuille d'acier inoxydable de 20 µm d'épaisseur.This arrangement makes it possible to start and stop the jet at controlled pressure values by acting on the following parameters: mechanical stiffness of the bellows, value of the preload closure, effective surface of the bellows. By way of example, the bellows can be produced from a sheet of stainless steel 20 μm thick.

Le dimensionnement optimal du soufflet assure, suivant les états ouvert ou fermé des électrovannes du circuit d'encre, les cycles suivants :

  • arrêt du jet : coupure franche du jet à la valeur de pression choisie et chute rapide de la pression dans la cavité 140 par ouverture de l'électrovanne de purge pendant la fermeture de l'électrovanne de pression ;
  • rafraîchissement de l'encre : l'ouverture de l'électrovanne de purge puis de l'électrovanne de pression permet de réaliser le rafraîchissement de l'encre, la buse étant obturée (pression de fonctionnement inférieure au seuil d'ouverture du soufflet) ;
  • démarrage du jet : la fermeture de l'électrovanne de purge pendant la phase de rafraîchissement provoque une brusque élévation de pression dans la cavité 140 et décolle le soufflet de la plaque à buse 141 à une valeur de pression définie.
The optimal dimensioning of the bellows ensures, according to the open or closed states of the solenoid valves of the ink circuit, the following cycles:
  • jet stop: abrupt shutdown of the jet at the selected pressure value and rapid drop in pressure in the cavity 140 by opening the purge solenoid valve while the pressure solenoid valve is closing;
  • refreshing the ink: opening the purge solenoid valve and then the pressure solenoid valve enables the ink to be refreshed, the nozzle being blocked (operating pressure below the bellows opening threshold);
  • start of the jet: the closing of the purge solenoid valve during the cooling phase causes a sudden increase in pressure in the cavity 140 and takes off the bellows from the nozzle plate 141 at a defined pressure value.

Une autre variante de dispositif de modulation d'un jet d'encre est représenté à la figure 3. Ce dispositif est fixé à une machine d'impression à jet d'encre grâce à une bride 50 et comporte un corps cylindrique 51 vissé à cette bride. A titre de variante, le dispositif peut être fixé à la machine par le corps cylindrique 51. Une plaque à buse 60 en forme de disque, obtenue par exemple par découpe chimique et gravure est disposée dans un logement de forme adapté, prévu dans le fond 53 du corps 51. Le fond 53 est percé d'un trou central 52 et comporte un conduit annulaire d'arrivée d'encre 54 communiquant avec un circuit d'encre équipé de vannes de pression et de purge non représenté. La plaque à buse 60 comporte un conduit annulaire 61 dirigé vers le haut et est percée d'un trou central 62 formant buse d'éjection ainsi que de trous 63 (un seul est visible sur la figure) faisant communiquer les conduits annulaires 54 et 61. Le volume constitué par les conduits 54 et 61 et par les trous de communication 63 forme l'équivalent d'une cavité.Another variant of an ink jet modulation device is shown in FIG. 3. This device is fixed to an ink jet printing machine by means of a flange 50 and comprises a cylindrical body 51 screwed to this flange. Alternatively, the device can be fixed to the machine by the cylindrical body 51. A nozzle plate 60 in the form of a disc, obtained for example by chemical cutting and etching is disposed in a housing of suitable shape, provided in the bottom 53 of the body 51. The bottom 53 is pierced with a central hole 52 and comprises an annular ink supply duct 54 communicating with a circuit ink equipped with pressure and purge valves not shown. The nozzle plate 60 has an annular conduit 61 directed upwards and is pierced with a central hole 62 forming an ejection nozzle as well as holes 63 (only one is visible in the figure) making the annular conduits 54 and 61 communicate The volume constituted by the conduits 54 and 61 and by the communication holes 63 forms the equivalent of a cavity.

La plaque à buse 60 est recouverte par une membrane métallique 55 jouant le rôle d'obturateur, un film souple 56 (en élastomère par exemple) étant interposé entre la membrane 55 et la plaque à buse 60 pour assurer l'étanchéité. La membrane 55 et le film souple 56 sont des éléments en forme de disque maintenus à leur périphérie par le serrage résultant du vissage du corps 51 sur la bride 50.The nozzle plate 60 is covered by a metal membrane 55 acting as a shutter, a flexible film 56 (made of elastomer for example) being interposed between the membrane 55 and the nozzle plate 60 to ensure sealing. The membrane 55 and the flexible film 56 are disc-shaped elements held at their periphery by the tightening resulting from the screwing of the body 51 on the flange 50.

Un actionneur piézo-électrique 70 est rendu solidaire de la membrane 55 et reçoit des signaux de commande électriques grâce au câble électrique 71. En variante, on pourrait utiliser un actionneur électromagnétique.A piezoelectric actuator 70 is made integral with the membrane 55 and receives electrical control signals by virtue of the electrical cable 71. As a variant, an electromagnetic actuator could be used.

Le fonctionnement du dispositif représenté à la figure 3 est identique au dispositif de la figure 2. La raideur du montage assure les deux positions stables aux valeurs de pression définies. Une tension continue peut être fournie à l'actionneur 70 pour permettre le soulèvement de la membrane 55 et du film souple d'étanchéité 56 qui y adhère, libérant ainsi la buse pour provoquer l'émission d'un jet d'encre. L'application de cette tension continue permet d'obtenir des transitoires de pression plus franches. La tension continue peut être positive ou négative pour aider à l'ouverture ou à la fermeture de la buse. Une tension alternative à laquelle est éventuellement superposée la tension continue permet de faire vibrer la membrane métallique 55 et de diviser le jet d'encre en une succession de gouttes. Lors de l'émission d'un jet, la tension continue offre la possibilité de modifier l'écoulement de l'encre grâce à une modification de la valeur de la tension. Ceci permet de réguler la vitesse du jet.The operation of the device represented in FIG. 3 is identical to the device of FIG. 2. The stiffness of the assembly ensures the two stable positions at the defined pressure values. A DC voltage can be supplied to the actuator 70 to allow the lifting of the membrane 55 and of the flexible sealing film 56 which adheres thereto, thus freeing the nozzle to cause the emission of an ink jet. The application of this DC voltage makes it possible to obtain more frank pressure transients. The DC voltage can be positive or negative to help open or close the nozzle. An alternating voltage to which the direct voltage is possibly superimposed makes the membrane vibrate 55 and divide the inkjet into a succession of drops. During the emission of a jet, the continuous tension offers the possibility of modifying the flow of the ink thanks to a modification of the value of the tension. This regulates the speed of the jet.

Cette disposition présente l'avantage de la compacité tout en limitant le nombre de pièces pour réaliser la fonction.This arrangement has the advantage of compactness while limiting the number of parts for performing the function.

Parmi les avantages procurés par la présente invention, on peut citer :

  • la suppression des instabilités de jet pendant les phases de rafraîchissement et d'arrêt en évitant les à-coups de pression jet en marche,
  • la coupure ou la mise en route correcte du jet en assurant l'ouverture et la fermeture de la buse à des valeurs de pression connues et répétitives,
  • la suppression au démarrage d'une pulvérisation d'air et d'encre en évitant l'introduction d'air dans la cavité,
  • le maintien en état de propreté de la sortie de la buse en évitant les écoulements d'encre à l'arrêt.
Among the advantages provided by the present invention, there may be mentioned:
  • elimination of jet instabilities during the cooling and stopping phases by avoiding pressure jets when the jet is running,
  • the correct cutting or starting of the jet by ensuring the opening and closing of the nozzle at known and repetitive pressure values,
  • the suppression at start-up of an air and ink spray while avoiding the introduction of air into the cavity,
  • keeping the nozzle outlet clean, avoiding ink spills when stopped.

Claims (11)

Dispositif permettant l'émission de matière sous forme d'un jet par l'intermédiaire d'une buse comportant au moins un orifice d'émission (62, 142), la buse pouvant communiquer avec une cavité (54, 61, 63 ; 140) du dispositif par où transite ladite matière et où elle est mise en pression pour permettre la formation dudit jet sous l'effet de moyens de commande, des moyens de stimulation (70, 125) étant situés à proximité de la buse pour fractionner le jet en une succession d'éléments, des moyens d'obturation de la buse en l'absence d'émission d'un jet de matière étant prévus, caractérisé en ce que les moyens d'obturation sont constitués par un organe déformable (55, 150), placé entre les moyens de stimulation et la buse et solidaire des moyens de stimulation, l'organe déformable étant conçu mécaniquement en fonction de la pression à laquelle est soumise ladite matière pour posséder le fonctionnement bistable suivant : - être dans une position d'obturation de la buse lorsque les moyens de commande n'autorisent pas l'émission d'un jet de matière, - être dans une position de libération de la buse lorsque les moyens de commande autorisent l'émission d'un jet de matière. Device for the emission of material in the form of a jet via a nozzle comprising at least one emission orifice (62, 142), the nozzle being able to communicate with a cavity (54, 61, 63; 140 ) of the device through which said material passes and where it is pressurized to allow the formation of said jet under the effect of control means, stimulation means (70, 125) being located near the nozzle to fractionate the jet in a succession of elements, means for closing the nozzle in the absence of emission of a jet of material being provided, characterized in that the means for closing consist of a deformable member (55, 150 ), placed between the stimulation means and the nozzle and integral with the stimulation means, the deformable member being designed mechanically as a function of the pressure to which said material is subjected in order to have the following bistable operation: - be in a closed position of the nozzle when the control means do not allow the emission of a jet of material, - be in a nozzle release position when the control means authorize the emission of a material jet. Dispositif selon la revendication 1, caractérisé en ce que, l'émission d'un jet étant commandée par la pression existant dans la cavité (140), l'organe déformable (150) comprend une partie (151) se trouvant entre les moyens de stimulation (125) et la buse, cette partie (151) étant reliée à un soufflet (153) autorisant un déplacement relatif de ladite partie par rapport à la buse (142), le soufflet (153), soumis sur l'une de ses faces à la pression de la matière dans la cavité (140), possédant des caractéristiques mécaniques telles que pour une pression de la matière n'autorisant pas l'émission d'un jet ladite partie (151) de l'organe déformable (150) obture la buse (142), et que pour une pression de la matière autorisant l'émission d'un jet ladite partie (151) de l'organe déformable est écartée de la buse (142).Device according to claim 1, characterized in that, the emission of a jet being controlled by the pressure existing in the cavity (140), the deformable member (150) comprises a part (151) located between the means of stimulation (125) and the nozzle, this part (151) being connected to a bellows (153) allowing a relative movement of said part relative to the nozzle (142), the bellows (153), subjected on one of its faces to the pressure of the material in the cavity (140), having mechanical characteristics such that for a pressure of the material not allowing the emission of a jet said part (151) of the deformable member (150) closes the nozzle (142), and that for a pressure of the material authorizing the emission of a jet, said part (151) of the deformable member is moved away from the nozzle (142). Dispositif selon la revendication 2, caractérisé en ce que, les moyens de stimulation (125) comportant un corps allongé (130), le soufflet (153) entoure le corps allongé et est fixé de manière étanche à ce corps allongé de façon que l'espace compris entre le corps allongé, le soufflet et la partie (151) de l'organe déformable (150) renferme un gaz.Device according to claim 2, characterized in that, the stimulation means (125) comprising an elongated body (130), the bellows (153) surrounds the elongated body and is tightly fixed to this elongated body so that the space between the elongated body, the bellows and the part (151) of the deformable member (150) contains a gas. Dispositif selon la revendication 3, caractérisé en ce que le gaz renfermé dans ledit espace est de l'air.Device according to claim 3, characterized in that the gas contained in said space is air. Dispositif selon l'une quelconque des revendications 2 à 4, caractérisé en ce que, lorsque l'émission d'un jet n'est pas autorisée, ladite partie (151) de l'organe déformable (150) est plaquée sur la buse (142), des moyens d'étanchéité (161) étant prévus entre ladite partie (151) et la buse (142).Device according to any one of Claims 2 to 4, characterized in that, when the emission of a jet is not authorized, said part (151) of the deformable member (150) is pressed against the nozzle ( 142), sealing means (161) being provided between said part (151) and the nozzle (142). Dispositif selon la revendication 1, caractérisé en ce que les moyens de commande comprennent un actionneur (70) agissant sur l'organe déformable (55) pour obturer ou libérer la buse (62).Device according to claim 1, characterized in that the control means comprise an actuator (70) acting on the deformable member (55) to close or release the nozzle (62). Dispositif selon la revendication 6, caractérisé en ce que ledit actionneur (70) sert également de moyen de stimulation du jet.Device according to claim 6, characterized in that said actuator (70) also serves as a means of stimulating the jet. Dispositif selon la revendication 7, caractérisé en ce que ledit actionneur (70) est un élément piézo-électrique ou électromagnétique comprenant des moyens pour recevoir une tension électrique continue afin de forcer l'organe déformable (55) à libérer la buse (62) et une tension alternative permettant de stimuler le jet.Device according to claim 7, characterized in that the said actuator (70) is a piezoelectric or electromagnetic element comprising means for receiving a continuous electric voltage in order to force the deformable member (55) to release the nozzle (62) and an alternating voltage to stimulate the jet. Dispositif selon l'une quelconque des revendications 6 à 8, caractérisé en ce que la buse (62) est contenue dans une plaque à buse (60), l'organe déformable (55) est une membrane maintenue dans le dispositif par sa périphérie, la plaque à buse, la membrane et l'actionneur formant une succession d'éléments empilés et centrés sur la buse, la plaque à buse (60) possédant l'une de ces faces principales en contact avec un conduit d'amenée (54) de ladite matière et l'autre de ses faces principales adjacente à la membrane (55), une communication (63) étant prévue entre les deux faces principales de la plaque à buse (60) pour le passage de ladite matière.Device according to any one of Claims 6 to 8, characterized in that the nozzle (62) is contained in a nozzle plate (60), the member deformable (55) is a membrane held in the device by its periphery, the nozzle plate, the membrane and the actuator forming a succession of elements stacked and centered on the nozzle, the nozzle plate (60) having one of these main faces in contact with a supply duct (54) of said material and the other of its main faces adjacent to the membrane (55), a communication (63) being provided between the two main faces of the plate to nozzle (60) for the passage of said material. Dispositif selon la revendication 9, caractérisé en ce qu'un film souple d'étanchéité (56) est intercalé entre la membrane (55) et la plaque à buse (60).Device according to claim 9, characterized in that a flexible sealing film (56) is interposed between the membrane (55) and the nozzle plate (60). Utilisation du dispositif selon l'une quelconque des revendications précédentes dans une tête d'impression pour imprimante à jet d'encre, l'encre constituant ladite matière.Use of the device according to any one of the preceding claims in a print head for an ink jet printer, the ink constituting said material.
EP97400545A 1996-03-14 1997-03-12 Device for the stimulated ejection of material under pressure by means of a closable nozzle Expired - Lifetime EP0795407B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9603222 1996-03-14
FR9603222A FR2746038B1 (en) 1996-03-14 1996-03-14 DEVICE ALLOWING THE EMISSION OF A SINGLE JET OF MATERIAL UNDER PRESSURE THROUGH A CLOSABLE NOZZLE

Publications (2)

Publication Number Publication Date
EP0795407A1 true EP0795407A1 (en) 1997-09-17
EP0795407B1 EP0795407B1 (en) 1999-10-27

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EP97400545A Expired - Lifetime EP0795407B1 (en) 1996-03-14 1997-03-12 Device for the stimulated ejection of material under pressure by means of a closable nozzle

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US (1) US5940100A (en)
EP (1) EP0795407B1 (en)
JP (1) JPH10792A (en)
CN (1) CN1166406A (en)
AU (1) AU722344B2 (en)
CA (1) CA2199692A1 (en)
DE (1) DE69700673T2 (en)
ES (1) ES2140188T3 (en)
FR (1) FR2746038B1 (en)

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AU2004233536B2 (en) * 2000-10-20 2005-10-20 Zamtec Limited A printhead having a nozzle arrangement with nozzle openings in moveable wall of the nozzle chamber
US6623101B1 (en) * 2000-10-20 2003-09-23 Silverbrook Research Pty Ltd Moving nozzle ink jet
CN101823237B (en) * 2010-04-29 2012-06-06 沈阳理工大学 Nozzle device of spiral core control flow beam for micro-abrasive air jet machining
CN104437940A (en) * 2014-12-24 2015-03-25 深圳市沃尔核材股份有限公司 Controllable leakage stop shower nozzle
CN105328995A (en) * 2015-12-15 2016-02-17 李星 Spraying head cleaning and moisturizing device
CN109303696B (en) * 2018-11-23 2021-05-14 秦艳 Supplementary dispensing device of clinical anesthesia

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Also Published As

Publication number Publication date
AU1629797A (en) 1997-09-18
EP0795407B1 (en) 1999-10-27
CN1166406A (en) 1997-12-03
JPH10792A (en) 1998-01-06
FR2746038B1 (en) 1998-05-07
DE69700673D1 (en) 1999-12-02
FR2746038A1 (en) 1997-09-19
AU722344B2 (en) 2000-07-27
CA2199692A1 (en) 1997-09-14
ES2140188T3 (en) 2000-02-16
US5940100A (en) 1999-08-17
DE69700673T2 (en) 2000-06-08

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