Device for sequencing the ignition of pyrotechnic products

Description

FIELD OF THE INVENTION

[0001] The invention relates to pyrotechnic devices such as those used to make fireworks. STATE OF THE ART

[0002] Fireworks are known to be made using pyrotechnic devices called firework bombs.

[0003] During the fireworks display, the bombs are usually ignited in a certain order and therefore following a certain sequencing to produce predetermined visual effects. The ignition device itself is often configured to produce this sequencing.

[0004] However, the implementation of this configuration is delicate due to the handling it requires and the risks of accidents it generates when it requires intervention on the pyrotechnic material.

[0005] One aim of the invention is to facilitate the production of the pyrotechnic device to obtain the desired sequencing.

[0006] US1598920A discloses a device for igniting pyrotechnic products, the device comprising: a base comprising a wick of a pyrotechnic material, an ignition tip, two, three or more transmission tips for pyrotechnic products, the wick connecting each transmission tip directly to the ignition tip. STATEMENT OF THE INVENTION

[0007] For this purpose, the invention provides a device for sequencing the ignition of pyrotechnic products, the device comprising: a base comprising an elongated fuse formed of a pyrotechnic material, an ignition tip, and at least two transmission tips for pyrotechnic products, the transmission tips extending at different distances from the ignition tip along the fuse, the wick connecting each transmission tip directly to the ignition tip.

[0008] Thus, when assembling pyrotechnic products, it is sufficient to attach pyrotechnic products to the transmission tips and an ignition member to the ignition tip. Given the configuration of the device, the pyrotechnic products are located at different distances from the ignition member along the fuse. Once the device is ignited by the ignition member, the fuse gradually burns and transmits the ignition energy first to the nearest pyrotechnic device, and only then to the next one, and so on. This results in a sequencing of the ignition. And thanks to the tips, during assembly and even after it, it is not necessary to perform any action on the pyrotechnic material. The invention improves safety when handling orders to be shipped to the site and when handling a fireworks display on a site. It increases the speed of production by up to a factor of 5.There is no generation of inert waste or pyrotechnic waste.

[0009] It can be provided that the transmission tips are connected to the base independently of each other. Advantageously, at least one of the transmission tips extends opposite the wick.

[0010] It can be provided that, for at least one of the transmission tips, the bit has a recess opposite the transmission tip.

[0011] This recess directs the flame from the wick towards the pyrotechnic device during combustion transmission. It reduces the risk of this transmission stopping.

[0012] For example, the recess has a conical shape.

[0013] This shape is particularly effective for this orientation of the dart.

[0014] It can be provided that the device has at least one relief for supporting an electric wire.

[0015] Such a relief, provided in one or more copies, allows the electric wire of the ignition member to be fixed to the device and / or wound therein. This provides safety against the risk of the wire or the ignition member being torn off in the event of unexpected traction on the wire, for example if someone inadvertently steps on the wire.

[0016] The invention also provides a pyrotechnic assembly comprising: at least one device according to the invention; an ignition member connected to the base, and at least two pyrotechnic products connected to the base.

[0017] It may be provided that each pyrotechnic product has a tip, for example a male tip, configured to make a male-female assembly with one of the transmission tips.

[0018] This makes it particularly easy to assemble the pyrotechnic products into the device.

[0019] Also provided according to the invention is a method of manufacturing a device for sequencing the ignition of pyrotechnic products, in which tips for pyrotechnic products are overmolded onto a base comprising an elongated wick formed of a pyrotechnic material, the tips being overmolded at different distances from one end of the wick along the wick.

[0020] Overmolding reduces the labor required for this production. It also avoids the use of glue, which can pose problems in pyrotechnics.

[0021] The invention further provides a method for assembling pyrotechnic products, in which at least two pyrotechnic products are fixed to a base comprising an elongated fuse formed from a pyrotechnic material and an ignition tip at different distances from the ignition tip along the fuse and such that the fuse connects each pyrotechnic product directly to the ignition tip. DESCRIPTION OF FIGURES

[0022] We will now present an embodiment of the invention by way of non-limiting example in support of the drawings in which: there figure 1 is an elevational view of a device according to one embodiment of the invention; figure 2 presents side, sectional and top views of the device of the figure 1 ; THE figures 3 à 5 are views of three stages of assembly of the device to pyrotechnic products.

[0023] It has been illustrated to the figures 1 et 2 a device 2 for sequencing the ignition of pyrotechnic products according to one embodiment of the invention.

[0024] The device 2 comprises a base or support 4 comprising a rigid tube 6, in this case cylindrical and rectilinear with longitudinal axis XX. The base also comprises an elongated slow fuse 8 formed from a pyrotechnic material completely filling the tube 6. The fuse is continuous from one end of the tube to the other. It is in one piece.

[0025] The device comprises an ignition tip or connector 10 made of plastic material, rigidly fixed to the base 4. In the present example, it is overmolded or attached to the base 4. It is fixed to a longitudinal end of the base, on the right in the figures. In this example, the base enters a housing of this tip. The tip 10 is entirely hollow and the wick 8 is in communication with the interior of the tip. The ignition tip has the general shape of a sleeve coaxial with the base and extends in the extension of the latter.

[0026] The device 2 also comprises several transmission tips 12a-e for pyrotechnic products. In the present example, the transmission tips are five in number but this number could take other values such as 2, 3, 4, 6 or more. The tips 12a-e are aligned along the base.

[0027] These tips are made of plastic and are rigidly attached to the base 4.

[0028] The three transmission tips 12b,c,d located in the middle of the alignment are here identical to each other.

[0029] In this example, each end piece 12b-e is overmolded to the base. Each of them is formed of a connecting collar 14 surrounding a respective section of the base 4 and a connecting sleeve 16 extending on one side of the collar from the latter. The sleeve 16 has an axis YY radial to the axis XX of the base. The tube 6 has orifices 18 putting the wick 8 in communication with the interior of the respective sleeves 16. In addition, the wick 8 has a recess 20 opposite each transmission end piece 12 and each orifice 18. In this case, the recess has a conical shape.

[0030] In this embodiment, the leftmost transmission endpiece 12e closes the base 4 at its left end. It closes the tube and guarantees the pressure and therefore the duration of the delay.

[0031] In the present example, the transmission end piece 12a located furthest to the right is made in one piece with the ignition end piece 10. Its axis YY is also radial to that of the base 8 and parallel to those of the other transmission end pieces 12b-e. It is not opposite the wick and opens directly into the ignition end piece.

[0032] Each transmission end piece 12 has in this case one or more annular internal cavities 13, for example two in number, each intended to cooperate with a complementary relief of a male end piece intended to penetrate into the transmission end piece and connected to a pyrotechnic product. This connection by double annular cavity makes it possible to withstand the pressure when fire passes through the male transmission end piece.

[0033] As seen in the figures, the transmission tips 12b-e are fixed to the base 8 at different distances from the ignition tip 10 along the wick 8, i.e. here along the axis XX. Each of them is in direct communication with the wick. The latter thus connects each transmission tip directly to the ignition tip so that a flame propagates directly from the wick to each transmission tip.

[0034] We therefore find along the device 2 the following five transmission tips in increasing order of distance from the ignition tip 10: the transmission end piece 12a in one piece with the ignition end piece, the transmission end pieces 12b-d in succession along the axis XX; and the transmission end piece 12e.

[0035] The device 2 carries two reliefs 22 formed here by hooks extending over the ignition end piece 10. The hooks are for example oriented in the direction of the transmission end piece 12e. They are used to attach an electric wire.

[0036] In the manufacturing process of this pyrotechnic product ignition sequencing device, the transmission tips 12b-e are overmolded onto the base 4 comprising the wick 8, and the ignition tip 10 is overmolded onto the base 4.

[0037] The method is implemented so that the transmission tips 12b-e are at different distances from the ignition tip 10 along the wick 8. Thus a flame propagates directly from the wick to each transmission tip.

[0038] To implement the method of assembling pyrotechnic products in this embodiment, we start from the device 2 thus constituted.

[0039] In reference to the figure 3 , respective pyrotechnic products 24 forming firework bombs are fixed to the transmission tips 12a-e and therefore to the base 4. Each of them comprises for this purpose a male tip 26 capable of producing a male-female assembly with the corresponding transmission tip 12a-e. The male tip 26 in this case has two annular reliefs 28 producing an assembly by complementary shape with the annular cavities 13 to ensure immobilization of the assembly by snap-fastening. The male tip is for example connected to the rest of the pyrotechnic product by a wicked conduit 30.

[0040] In reference to the figure 4 , a male end piece 32 of an ignition member 34 is similarly fixed to the ignition end piece 10.

[0041] These fixing steps are implemented, taking into account the arrangement of the device, so that the pyrotechnic products, more precisely their tips 26, are at different distances from the ignition member 34, more precisely from its tip 10, along the wick. The wick connects each pyrotechnic product directly to the ignition tip.

[0042] We then obtain the pyrotechnic assembly of the figure 5 including: the sequencing device 2; the ignition member 34 connected to the base 4, and the pyrotechnic products 24 connected to the base 4.

[0043] This assembly can be carried out in the workshop or directly on the firing site.

[0044] During the fireworks, the ignition is triggered by action on the ignition member 34. The latter first causes the ignition of the product 24 furthest to the left on the figure 5via the transmission nozzle 12a and immediately after lighting the wick 8.

[0045] This gradually burns along its length and in doing so sequentially and directly ignites each of the pyrotechnic products associated with the respective 12b-e transmission tips, the last being the one associated with tip 12e.

[0046] The time interval separating the ignition of two successive products 24 is for example 2, 3, 4 or 5 seconds depending on the diameter given to the wick 8, which here is 8 mm.

[0047] This is therefore an advantageous way of carrying out clustering, namely of linking firework bombs in order to ensure the sequenced departure of several products from a single impulse.

[0048] It can be observed that any pyrotechnic product can easily be adapted to be connected to the device 2 of the invention. In this case, it is sufficient to attach a male ignition tip 32 to it, for example by means of adhesive tape.

[0049] Pyrotechnic products 24 can be of the same caliber or of different calibers.

[0050] Many modifications can be made to the invention without departing from its scope.

[0051] The wick 8 may have a non-rectilinear shape, for example curved. The distance measurement is then made by following the average fiber of the wick.

[0052] The male-female configuration of the tips can be reversed or other methods of assembling the tips can be provided.

[0053] It is possible to dispense with the need for a transmission end piece 12a made in one piece with the ignition end piece 10.

Claims

1. Device (2) for sequencing the ignition of pyrotechnic products, the device comprising: - a base (4) comprising an elongated wick (8) formed from a pyrotechnic material, - an ignition tip (10), and - at least two transmission tips (12b-e) for pyrotechnic products (24), the transmission tips extending at different distances from the ignition tip along the wick, the wick connecting each transmission tip directly to the ignition tip.

2. Device according to the previous claim, wherein the transmission tips (12be) are connected to the base independently of one another.

3. Device according to one of the previous claims, wherein at least one of the transmission tips (12b-e) extends opposite the wick (8).

4. Device according to one of the preceding claims, wherein, for at least one of the transmission tips, the wick (8) has a recess (20) opposite the tip.

5. Device according to the preceding claim, wherein the recess (20) has a conical shape.

6. Device according to one of the preceding claims, which has at least one protrusion (22) for supporting an electrical wire.

7. Pyrotechnic assembly comprising: - at least one device (2) according to any of the preceding claims; and - at least two pyrotechnic products (24) connected to the base.

8. Assembly according to the previous claim, in which each pyrotechnic product (24) comprises a tip (26), for example a male tip, configured to form a malefemale assembly with one of the transmission tips (12b-e) of the device.

9. Method of manufacturing a device (2) for sequencing the ignition of pyrotechnic products, in which tips (12b-e) for pyrotechnic products (24) are overmolded onto a base (4) comprising an elongated wick (8) formed of a pyrotechnic material, the tips being overmolded at different distances from one end of the wick along the length of the wick.

10. Method of assembling pyrotechnic products, in which at least two pyrotechnic products are fixed to a base (4) comprising an elongated wick (8) formed of a pyrotechnic material and an ignition tip (24) at different distances from the ignition tip along the wick and in such a way that the wick connects each pyrotechnic product directly to the ignition tip.