DEVICE FOR DEPOSITTING PASTY PATTERNS INTO A TUBE

Abstract

The invention relates to a device for depositing paste-like patterns onto the surface of a tube channel. The device comprises a frame supporting a first mechanical assembly A for holding, positioning, and moving the tube, and a second mechanical assembly B for extruding paste to deposit said paste-like patterns. Assemblies A and B cooperate with each other. (See Figure 16 for abbreviations.)

Description

Title of the invention: Device for depositing paste-like patterns in a tube Scope of the invention

[0001] The technical field of the invention is primarily that of tubes for cylindrical propellant charges having a central channel, used in munitions. Prior art

[0002] The propellant charges equipping shells and missiles are ignited by means of an igniter associated with a firing tube. The firing tube consists of a combustible tube enclosing an ignition charge based on fast-burning igniting powder. This firing tube is located in the channel of the propellant charge.

[0003] French patent application FR-A-2 593 905 describes an ignition charge arranged in a fuel tube consisting of a stack of agglomerated ignition powder tablets. These assemblies for ignition tubes require, on the one hand, the manufacture of agglomerated powder tablets, and on the other hand, their placement in the fuel tube.

[0004] However, filling the fuel tube with the ignition charge is a delicate operation, both in terms of the handling technique and the pyrotechnic risk (ignition powder is classified as hazard division 1.1 according to the UN GHS classification (Globally Harmonized System of Classification and Labelling of Chemicals (UN)). This operation requires special equipment to be automated. Furthermore, when the ignition charge is introduced into the tube mixed with collodion to obtain (in situ) tablets, the evaporation time of the collodion solvent is long due to the confinement of the loaded collodion within the tube.

[0005] Furthermore, it is sometimes necessary to remove the igniter tube from a propellant charge, for example, when disposing of or neutralizing a munition. Removing the igniter tube involves extracting the ignition charge contained within the propellant tube. This extraction, through direct contact with the agglomerated powder, creates a pyrotechnic hazard.

[0006] French patent application FR-A-2 725 781 proposes a method for better distributing the powder charge in the ammunition channel and facilitates the removal of the ignition material compared to agglomerated powder ignition material. To achieve this, the agglomerated powder tablets are replaced by an ignition material comprising a powdered ignition composition (typically black powder) deposited on a flexible support sheet, which is It is then advantageously rolled up on itself to be inserted into a combustible tube to form an igniter tube. To prevent the powder (which is simply placed on the flexible support) from falling to the bottom of the igniter tube, it is essential to cover the powder composition with another flexible sheet (called a shield sheet), with at least one of the shield and support sheets being coated with adhesive. However, implementing this process is complex due to the handling of the explosive ignition powder, classified as hazard division 1.1, the need to control the consistency of the quantities of powder deposited in piles on the flexible sheet and the geometries of the piles, and the step of covering the powder piles on the flexible sheet with the adhesive shield sheet. Furthermore, the configuration possibilities for pyrotechnic devices are limited and determined solely by the mass and spatial distribution of the powder piles.

[0007] It would therefore be useful to have a device for depositing paste-like patterns of various geometries into a combustible tube. The present invention aims to meet this need. Summary of the invention

[0008] The present invention relates to a device for depositing paste-like patterns onto the internal or external surface of a tube channel. The device comprises a frame C supporting a first mechanical assembly A for holding, positioning, and moving the tube, and a second mechanical assembly B for extrusion, assemblies A and B cooperating with each other. The invention also relates to a method implementing the aforementioned device. Brief description of the figures

[0009] [fig. 1] Fig. 1 schematically represents the reference points for the movement of the device of the invention in a combustible tube.

[0010] [fig.2] Fig.2 schematically represents assemblies A and B, chassis C, and a D control module.

[0011] [fig.3] Fig.3 shows the assembly of assemblies A and B on chassis C.

[0012] [fig.4] Fig.4 shows the displacement of the fuel tube along the X axis.

[0013] [fig.5] Fig.5 shows a cartridge implemented in the device of the invention.

[0014] [fig.6] Fig.6 shows the direction of rotation of the fuel tube and the orientation of the nozzle for obtaining a circular or helical deposit.

[0015] [fig.7] Fig.7 illustrates a circular deposit of paste in a combustible tube.

[0016] [fig.8] Fig.8 illustrates a helical deposit of paste in a combustible tube.

[0017] [fig.9] Fig.9 represents assembly A of the device of the invention.

[0018] [fig.10] Fig.10 shows the elements of assembly A ensuring the movements in XetY.

[0019] [fig.l 1] The [fig.l 1] represents a variant of assembly B of the device of the invention.

[0020] [fig. 12] Fig. 12 represents a variant of assembly B of the device the invention.

[0021] [fig. 13a] Fig. 13a represents a state of the device of the invention when it is put into artwork.

[0022] [fig. 13b] Fig. 13b represents a state of the device of the invention when it is put into operation. implemented.

[0023] [fig. 14] Fig. 14 represents a state of the device of the invention when it is put into artwork.

[0024] [fig. 15] Fig. 15 represents a state of the device of the invention when it is put into artwork.

[0025] [fig. 16] Fig. 16 represents a state of the device of the invention when it is put into artwork.

[0026] [fig. 17] Fig. 17 represents a state of the device of the invention when it is put into artwork.

[0027] [fig. 18] Fig. 18 illustrates a helical deposit of paste in a combustible tube.

[0028] [fig. 19] Fig. 19 illustrates a helical deposit of paste in a combustible tube. Description of the invention

[0029] The present invention relates, according to a first aspect, to a device for depositing paste-like patterns, in particular ignition charge, onto the internal or external surface, preferably internal, of a channel in a tube, in particular a fuel tube. The following description takes as its reference the horizontal Y-axis positioned along the central axis of the tube, the X-axis along a horizontal direction orthogonal to the Y-axis, the Z-rotation about the Y-axis (tube rotation), and the E-rotation about the Y-axis (syringe pusher screw rotation), as shown in [fig. 1].

[0030] The device comprises a chassis C supporting two mechanical assemblies A and B which cooperate:

[0031] - a first assembly A for holding, positioning and moving the tube; - a second extrusion assembly B.

[0032] As illustrated in [Fig. 2], the first assembly A comprises two superimposed tables allowing movement along the X and Y axes, and incorporates on the upper table a system for holding and rotating the tube about a Z axis of rotation. The second assembly B comprises a plate supporting a linear thrust system and a cylindrical cartridge. The cartridge contains the ignition loading paste to be deposited. The cartridge is extended at one of its ends. by a tubular elbow extension fitted with an extrusion nozzle, and contains at its other end a sliding piston with piloted movement.

[0033] These two assemblies A and B are mounted on the same chassis C so that the longitudinal axis Yc of the cartridge and the axis of revolution Yt of the tube are coplanar in the (X, Y) plane, as shown in [fig.3].

[0034] Assembly A has a movable axis driven by a stepper motor allowing the tube to be moved along the X axis and the Yt axis of the tube to be aligned with the longitudinal Yc axis of the cartridge, as shown in [fig.4].

[0035] For the deposition phase, assembly A ensures the movement of the tube, firstly, through rotation Z around its central axis Y and, secondly, through translation along the Y axis. The two rotational and translational movements are driven separately by controlled actuators. These actuators are, for example, stepper motors controlled by software interfaces of the type known for 3D printers. The rotational and translational movements of the tube can be continuous or discontinuous, with steps at constant or variable speed.

[0036] Assembly B supports a cylindrical cartridge containing the ignition loading paste, mounted on a fixed table, as shown in [Fig. 5]. The cartridge is oriented along the Y-axis and has at one end, towards the tube, a bent tubular extension terminating in an extrusion nozzle. The cartridge and the nozzle are therefore not mobile along the Y-axis, but the horizontal movement of the tube along the Y-axis, provided by assembly A, is sufficient for the nozzle to penetrate the tube channel along its entire length. A piston, actuated within the cartridge body by a cylinder or a worm gear, is capable of translational movement within the cartridge body and along the longitudinal Yc-axis. The translational movement of the cylinder or screw is generated by a stepper motor controlled by a software interface, for example, of the type used in 3D printers. During the deposition phase, the paste flow rate through the nozzle is regulated by the movement of the piston.The paste extruded by the nozzle is deposited onto the surface of the tube channel to form the desired pattern(s).

[0037] The angular orientation of the nozzle in the (Y, Z) plane is crucial for the quality of the deposit in the tube. This angular orientation depends in particular on the viscosity of the paste, the rotation speed of the tube, and the adhesion of the paste to the tube. Advantageously, the nozzle is oriented at approximately 225° for a counterclockwise rotation of the tube to obtain a circular or helical deposit (the tube then also being in translational motion), as shown in [Fig. 6].

[0038] The coordination of the movements of the tube (rotating around the Y-axis and translating along the Y-axis) and the cartridge piston along the Y-axis allows for constant control of the position of the deposit in the tube channel and the quantity of paste deposited. This coordination is ensured, for example, by a program in engine control format taking into account as input data the characteristic quantities of the deposit (mass deposited, patterns...) of the ignition charge and those of the tube (diameter, length...).

[0039] In one embodiment, the cartridge is temperature-conditioned so as to maintain the viscosity of the paste at a value allowing its extrusion and flowability.

[0040] This device allows for the deposition of paste patterns in the tube according to various geometries, for example, linear patterns along the tube's axis, circular, helical, or triangular (chevron) patterns. Several patterns can be deposited successively in the tube's channel, for example, several helical patterns offset angularly or interlacing patterns. The amount of paste deposited within a single pattern can also vary according to its position in the channel by varying the advance speed of the syringe piston and / or the rotation / translation speeds of the tube. It is also possible to obtain paste patterns with different compositions, either by introducing at least two layers of different compositions into the cartridge, or by repeating the deposition operation with cartridges containing different compositions.

[0041] The tube is, for example, made of plastic, metal, or fibrous material. Advantageously, the tube is made of combustible fibrous material of the type used for propellant loading. By way of example, the fuel tube, such as those marketed by Eurenco, is composed of 60% to 80% by mass of cellulosic ester, 17% to 37% by mass of cellulose, 3% to 7% by mass of resin, and 0% to 2% by mass of stabilizing additive (the sum of these constituents being equal to 100%). Its mass is approximately 15 g to 25 g. The fuel tube has a height of approximately 120 mm to 140 mm, an internal diameter of 25 mm to 30 mm, and a thickness of 1.5 to 2.5 mm.

[0042] Advantageously, the combustible tube has the composition given in Table 1 and the dimensions given below.

[0043] [Tables 1] Composition % by mass: Nitrocellulose powder cotton 69%, Cellulose 25%, Resin 5%, Stabilizing additive 1%

[0044] The mass of such a combustible tube is 18 g + / - 3 g, its height is 126 mm, for an inner diameter of 28 mm and a thickness of 1.8 mm.

[0045] In one embodiment, the surface of the tube may be prepared, prior to the application of the paste, by sanding or by applying a primer to promote adhesion of the paste during deposition.

[0046] In one embodiment, the tube installed on the device of the invention may be a multiple of the length of the unit tube forming the channel of the munition; it is then, after deposition, cut into sections of equal length to that of the unit tube.

[0047] The cartridge containing the paste is, for example:

[0048] - a simple syringe fitted with its piston, the tip of which has been cut to receive the tubular extension, or

[0049] - a plastic cartridge fitted with a piston of the type used for the extrusion of masonry pastes or silicone sealants, or

[0050] - a cylindrical body equipped with a piston receiving a flexible cylindrical pouch of the type of those marketed by the company Titanobel or by the company Würth France.

[0051] In one embodiment, the cartridge is automatically filled with paste from a paste reservoir. A tubular connection between the reservoir and the cartridge allows the cartridge to be filled when the piston is retracted, freeing up the cartridge's volume. This eliminates the need to replace the cartridge after its paste contents have been used for a new deposit.

[0052] The deposited paste may retain its pasty appearance or solidify (for example, through evaporation of solvent(s) or crosslinking of a polymer). The patterns obtained after deposition are therefore either pasty or solid, depending on the desired finished product. It is possible that some of the patterns may retain their pasty appearance while others solidify, depending on the compositions of the deposited pastes (by incorporating at least two different compositions into the cartridge, or by successively applying at least two different compositions).

[0053] In an embodiment adapted to the deposition of an ignition charge in the fuel tube, the paste consists of a collodion charged with an ignition powder, which solidifies by evaporation of the solvent(s) after deposition to lead to solid patterns.

[0054] Collodion is of the nitrocellulose base + solvent(s) type. In one embodiment, the nitrocellulose base of the collodion consists of a cellulose ester (approximately 70% to approximately 90% by mass) and generally also contains, conventionally, at least one plasticizer (approximately 1% to approximately 20% by mass, preferably approximately 10% by mass) and at least one stabilizer for the cellulose ester (approximately 0.5% to approximately 5% by mass). It also generally contains at least one additive (>0% to approximately 1% by mass), for example, selected from anti-adhesion agents, anti-glare agents, and antioxidants. It may contain a residual amount of solvent(s), in particular phlegmatizing solvent(s) and / or solvent(s) for dissolving the cellulose ester used during its manufacture.

[0055] Advantageously, the cellulosic ester used as the major component is chosen from cellulose nitrate, cellulose acetate or nitrocellulose, the latter being preferred. The nitrogen mass content of nitrocellulose is conveniently from 10.5% to 13.5%, an example being grade E nitrocellulose with a nitrogen mass content of 11.8% to 12.3%, advantageously equal to 12%.

[0056] The plasticizer used to prepare the collodion may be, in particular, a ketone (such as camphor), a vinyl ether (such as LUTONAL® A50 marketed by BASF), a polyurethane (such as NEP-PLAST 2001 marketed by Hagedom-NC), an adipate (such as dioctyl adipate) or a citrate (such as triethyl 2-acetyl citrate).

[0057] The stabilizer used to prepare the collodion may be, in particular, a compound whose chemical formula includes aromatic rings (opportunity two aromatic rings), capable of binding the nitrogen oxides from the decomposition of nitric esters (presently nitrocellulose). Examples of stabilizers include 2-nitrodiphenylamine (2NDPA), 1,3-diethyl-1,3-diphenyl urea (centrality I), 1,3-dimethyl-1,3-diphenyl urea (centrality II), and 1-methyl-3-ethyl-1,3-diphenyl urea (centrality III).

[0058] The optional additive used to prepare the collodion can be chosen in particular from among the anti-stick agents, such as silicone-type anti-stick agents, anti-glare agents, antioxidants, colorants, surfactants, anti-caking agents and hydrophobic agents.

[0059] The solvent can be a dual solvent of the type acetone / butyl acetate (BA) at 50% / 50% by mass.

[0060] Collodion is advantageously formulated to lead to a dry extract (after evaporation of the solvent) of 10% to 40%, by mass.

[0061] For guidance purposes, Table 2 below presents a formulation of collodion with 14% dry extract by mass.

[0062] [Tables 2] Collodion Composition (% by mass) Nitrocellulose Base Nitrocellulose 84 14 Plasticizer 10 Stabilizer 3.5 Other (additive(s), water, solvent...) 2.5 Total 100 AB 43 Acetone 43 Total 100

[0063] In one embodiment, the collodion loaded with ignition powder(s) comprises approximately 50% to approximately 70% by mass of powder(s), and the remainder to 100% (i.e., approximately 30% to approximately 50% by mass) of collodion. Conventionally, the ignition powder(s), previously prepared, is / are added to the collodion.

[0064] Conventionally, the ignition powder(s), previously prepared, is / are added to the collodion. The powder used is preferably black powder (PN) with the following mass composition:

[0065] - potassium nitrate (saltpeter): ~ 75% - charcoal: ~ 15% - sulfur: ~ 10%.

[0066] Collodion loaded with ignition powder is advantageously obtained by adding the ignition powder, previously prepared, to the solvent. It is then called "Blessed B". It differs from those of the prior art, designated "Blessed", obtained by separate additions to the collodion of the constituents of the ignition powder and without plasticizer. By way of example, Table 3 below gives an example of the composition of collodion from Table 2, loaded with PN7 ignition powder (which is a fine-grained powder).

[0067] [Tables 3] Raw materials Mass (g) Composition (% by mass) PN7 10.36 56 Collodion 8.14 44 Total 18.5 100

[0068] Collodion loaded with ignition powder is classified in risk division 1.4 according to the UN GHS classification. The hazard zones to be taken into account for handling the loaded collodion are therefore reduced, which facilitates the operations of depositing the collodion onto the tube.

[0069] After drying (solvent evaporation) of the loaded collodion, the dry product (i.e., the ignition charge) comprises approximately 88% to approximately 92% by mass of ignition powder(s), approximately 7% to approximately 10% by mass of cellulose ester, the remainder to 100% being provided by at least one compound selected from a plasticizer, an additive, and a residual solvent. For illustrative purposes, the dry product obtained after drying (solvent evaporation) of the collodion in Table 3 contains the mass ratios indicated in Table 4 below.

[0070] [Tables4] Composition: Dry Benite B Mass (g) % by mass PN7 10.36 90.08 Nitrocellulose 0.96 8.35 Plasticizer 0.11 0.96 Stabilizer 0.04 0.35 Residues (water, solvent...) 0.03 0.26 Total 11.50 100.00

[0071] The viscosity of the paste is adapted so as to allow its loading by pouring into the cartridge, its extrusion through the nozzle, and its non-flowing deposition on the tube.

[0072] Any geometry and arrangement of patterns on the inner surface (channel) of the tube via the implementation of the device of the invention can be envisaged.

[0073] In the case of ignition loading, particular consideration is given to spaced point patterns, or spaced circular patterns along the length of the channel, or linear patterns along the length of the channel, or one or more helical patterns along the length of the channel. The deposits are not all necessarily identical in dimensions and / or composition and are not all necessarily arranged in the same way. regular.

[0074] The number of deposits, their geometry, and their arrangement constituting the ignition charge in the tube channel are parameters for adjusting the ignition charge. Figures 7 and 8 show examples of ignition charge shapes deposited in a tube channel.

[0075] As previously stated, the device according to the invention comprises two assemblies A and B, mounted on the same frame C, which cooperate. Assembly A is suitable for holding and controlling the movement of the tube, while assembly B is fixed and supports a cylindrical cartridge containing the paste to be deposited. The motors (see below) of assemblies A and B are controlled by a control module D.

[0076] Assembly A comprises the elements described below, shown in [Fig. 9].

[0077] Tube 1 is positioned between rollers 2a, 2b, and 3 arranged in a triangle. Rubber rings 4 are placed on rollers 2a and 2b to ensure rotational drive contact with tube 1. Rollers 2a and 2b have a circular shoulder 5 at their ends to hold tube 1 in position along the Y-axis. Each roller also has, at its end opposite assembly B, a gear 6a, 6b. These gears 6a, 6b cooperate with a gear 7 coupled to a shaft rotated by a stepper motor 8 controlled by software of the type used in 3D printers.

[0078] The three rollers 2a, 2b and 3 are assembled and thus fixed by means of brackets to the table 9a. The roller 3 in the upper position is provided with means allowing it to be released in order to position the tube 1 on the rollers 2a and 2b, and then to fold it down into contact above the tube 1. In one embodiment, the roller 3 is held with an articulated arm 10 connected to the table 9a.

[0079] As shown in [Fig. 10], table 9a is mounted on a second table 9b. The connections between these two tables and the frame C are achieved by means of bushings, for example ball bushings (sliding on rails), for guidance, and toothed pulleys and belts for movement. This allows movement of table 9a along the X-axis relative to table 9b (movement generated by motor 11) and movement of table 9b along the Y-axis relative to the frame C (movement generated by motor 12). The entire assembly is controlled by software of the type used for 3D printers. This degree of freedom allows the table 9a to be moved laterally along the X axis to facilitate the positioning and removal of the tube 1 within the three rollers 2a, 2b and 3. It also allows precise positioning of the table 9a to coincide the Yt axis of the tube 1 with the Yc axis of the cartridge 19 (see below).

[0080] Assembly B, arranged opposite assembly A, comprises the elements described below, represented on [fig. 11].

[0081] A fixed table 13 supports two rings 14a and 14b, such as ball bushings, sliding on guide rails collinear with the Y axis, allowing the sliding of a carriage 15. This carriage 15 is set in motion by a worm gear 16 driven by a stepper motor 17. The carriage 15 allows the piston 18 of the cartridge 19 containing the paste to be set in motion by means of a connecting rod 20.

[0082] The table 13 is arranged on the frame C. When the cartridge is a syringe, the rod 20 and the piston 18 (also called the stop in syringe terminology) form a single piece. The plunger of the syringe's piston 18 is housed in a central chamber 21, equipped with a clasp, of the carriage 15. The clasp provides the connection in the central chamber 21 between the plunger of the piston 18 and the carriage 15. A cradle 22 fixed to the table 13 holds the body of the syringe. The central chamber 21 of the carriage 15 and the cradle 22 are aligned and arranged so that the axis of the syringe Yc is collinear with the Y-axis. A tubular extension 23 ending in a nozzle 24 is arranged at the end of the syringe in place of the original syringe tip.

[0083] As shown in [fig.12], when the cartridge 19 is a cylindrical body fitted with a piston, the rod 20 is fixed at the center to the piston 18. At its other end, the rod 20 is held by a clasp in a central chamber 21 of the carriage 15. The cartridge 19 is fitted at one of its ends with a bent tubular extension 23 ending in a nozzle 24. Two tabs 25a and 25b are fixed opposite each other on the table 13. Tab 25a has a bore with a counterbore and the other 25b has a half-bore with a shoulder so as to accommodate the two ends of the cartridge (in the manner of a gun for a masonry cartridge). The legs 25a and 25b fixed to the table 13 and the central chamber 21 of the carriage 15 are aligned and arranged so that the axis of the cartridge Yc is collinear with the Y axis.

[0084] According to another aspect, the invention relates to a method for depositing paste-like patterns onto the surface (internal or external, preferably internal) of a tube channel. The following describes an embodiment of the device of the invention for depositing a helical ignition loading pattern onto the internal surface of a fuel tube, using a cylindrical-bodied cartridge with a piston as the cartridge containing the ignition loading paste.

[0085] At the start of implementation, the articulated arm 10 supporting the roller 3 is unfolded and the position of the table 9a is offset relative to the Yc axis of the cartridge in order to facilitate the placement of the tube 1. The tube 1 is placed on the rollers 2a and 2b as shown in [Fig. 13a]. Then the roller 3 is brought into contact with the upper part of the tube 1 as shown in [Fig. 13b].

[0086] The carriage 15 is then moved back towards the motor 17 so as to leave space free for positioning the cartridge 19. The cartridge 19 contains the paste and is equipped with its Piston 18, connected to rod 20, is positioned on lugs 25a and 25b. Then carriage 15 is advanced to secure the end of rod 20 in chamber 21, which is fitted with a clasp. The state of the device at this stage of implementation is shown in [Fig. 14].

[0087] Priming the cartridge 19 allows the tubular extension 23 and the nozzle 24 to be filled with paste by moving the piston 18 until paste 26 begins to be extruded from the nozzle 24, as shown in [fig. 15].

[0088] The table 9a is then moved along the X axis by actuation of the motor 11 so as to align the axes Yt of the tube 1 and Yc of the cartridge 19. The device is then in the state shown in [fig. 16].

[0089] The table 9b is then moved along the Y axis by means of the motor 12 so as to make the paste extrusion nozzle 24 penetrate the initial deposition point in the channel of the tube 1, as shown in [fig. 17].

[0090] The tube 1 is then rotated by means of the motor 8, and the deposition phase is then initiated by simultaneously actuating the motor 12 causing the movement of the tube 1 along the Y-axis and the motor 17 causing the advancement of the piston 18 of the cartridge 19. The combination of the actions generated by each of the three motors 8, 12 and 17 leads to a helical deposition of paste 27 on the inner surface of the tube as shown in Figures 8, 18 and 19. After the deposition of the pattern, the tables 9a and 9b are returned to their initial position and the tube is removed from the device.

[0091] As an indication, the parameter setting shown in Table 5 can be used for the implementation of the device as described above.

[0092] [Tables5] Tube dimensions (inner diameter): 28.5 mm / Length x Height: 126 mm; Paste density: 1.2 g / cm³; Cartridge dimensions (inner diameter): 20.2 mm / Usable length: 78 mm; Nozzle diameter: 6 mm; Nozzle tilt: 235° (or 8 o'clock); Speed ​​[Mrot_tube]: 2 rpm; Speed ​​[My_tube]: 14 mm / min; Speed ​​[My_piston]: 7 mm / min; Linear mass of paste deposited: 16.5 g / mL; Pattern length: 1000 mm

[0093] The device of the invention is useful for depositing paste patterns inside a tube, and more particularly for obtaining ignition tubes for propellant charges. It can also be used for any application requiring the deposition of patterns in a tube, for example, in the industrial, pharmaceutical or food sectors.

Claims

Demands

1. Device for depositing paste patterns, in particular ignition loading, on the surface of the channel of a tube (1), in particular a fuel tube, the device comprising a frame supporting a first mechanical assembly A for holding, positioning and moving the tube, and a second mechanical assembly B for extruding paste for depositing said paste patterns, the assemblies A and B cooperating with each other; and the assembly A: - comprises two superimposed tables (9a), (9b) allowing movement along a horizontal Y axis positioned along the central axis of the tube and along an X axis positioned along a horizontal direction orthogonal to the Y axis, and - integrates on the upper table (9a) a system for holding and rotating the tube about an axis of rotation Z.

2. Device according to claim 1, wherein the table (9a) comprises: - a tube (1) positioned between rollers (2a), (2b) and (3) fixed on said table (9a), the rollers (2a) and (2b) each comprising at one end a circular shoulder (5) allowing the tube (1) to be held in position along the Y axis, and at the other end a toothed wheel (6a, 6b); - a motor (8) allowing the rotation of the rollers (2a) and (2b) to be driven via a shaft coupled to a toothed wheel (7) cooperating with the toothed wheels (6a, 6b).

3. Device according to claim 2, wherein the roller (3) is provided with means for releasing it in order to position the tube (1) on the rollers (2a) and (2b), and then to fold it down into contact above the tube (1).

4. Device according to any one of claims 1 to 3, wherein the table (9b) is fixed to the frame (C), the table (9a) being mounted on the table (9b) so as to permit movement of the table (9a) along the X axis relative to the table (9b), and movement of the table (9b) along the Y axis relative to the frame (C).

5. Device according to any one of claims 1 to 4, wherein assembly B comprises - a fixed table (13) supporting two rings (14a) and (14b) sliding on guide rails collinear with the Y axis; - a carriage (15) set in motion by a worm gear (16) driven by a motor (17); - a cartridge (19) comprising a piston (18) equipped with a connecting rod (20), a tubular extension (23) and a nozzle (24).

6. Device according to claim 5, wherein the cartridge is a syringe, and wherein: - the rod (20) and the piston (18) form a single piece; - the plunger of the piston (18) of the syringe is housed in a central chamber (21), provided with a clasp, of the carriage (15); - the body of the syringe is held by a cradle (22); - the central chamber (21) and the cradle (22) are aligned and arranged so that the axis of the syringe Yc is collinear with the Y axis.

7. Device according to claim 5, wherein the cartridge is a cylindrical body equipped with a piston, and wherein: - the rod (20) is fixed at the center to the piston (18); - at its other end, the rod (20) is held by a clasp in a central chamber (21) of the carriage (15); - two tabs (25a) and (25b) are fixed opposite each other on the table (13), tab (25a) having a bore with a counterbore and tab (25b) a half-bore with a shoulder so as to accommodate the two ends of the cartridge; - tabs (25a) and (25b) and the central chamber (21) are aligned and arranged so that the axis of the cartridge Yc is collinear with the Y axis.

8. Method for depositing paste-like patterns, in particular ignition loading patterns, on the surface of the channel of a tube (1), in particular a fuel tube, by implementing the device according to any one of claims 1 to 7.

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