Classifications

• • A—HUMAN NECESSITIES
  • A62—LIFE-SAVING; FIRE-FIGHTING
  • A62C—FIRE-FIGHTING
  • A62C13/00—Portable extinguishers which are permanently pressurised or pressurised immediately before use
  • A62C13/76—Details or accessories

Definitions

• the manufacturing process typically consists of extrusion steps, necking of the neck and tapping of the latter.
• the current manufacturing principles typically consist of steps of stamping the bottom or of the tank body, machining the threaded ring or studs, manufacturing the ferrule, welding and assembly. of the different elements.
• These metallic embodiments have drawbacks.
• the metallic materials are hard and aggressive and do not facilitate the handling of the extinguisher by inexperienced people. Manufacturing waste is often significant after quality control. Manufacturing performance is poorly controlled. The normative residual rate set at 10% is often exceeded.
• the circular cylindrical shapes adopted by the manufacturers unanimously are difficult to incorporate into an interior cockpit, such as an engine cockpit, a pleasure boat, a dwelling, so that the extinguishers occupy an excessive useful space or remain confined far from the points sensitive and risk of fire.
• Document EP283568 describes a fire extinguisher of the aforementioned type, the reservoir of which is made of plastic by a process of drawing and blowing a preform. This manufacturing method makes it easier to obtain reservoirs with various shapes.
• stretching involves pinching the preform to exert a pulling force on it. Such pinching produces a weld zone between two opposite walls of the preform, zone which constitutes a point weak in the container thus obtained. Therefore, the working pressure of this known fire extinguisher is limited to 25 bar.
• the present invention aims to remedy at least some of these drawbacks.
• the invention provides a fire extinguisher comprising a plastic tank capable of containing an extinguishing agent under pressure and an ejection device fixed on a neck of the tank to control an ejection of the agent.
• the ejection device comprising an outlet nozzle and a dip tube arranged in the reservoir so as to be able to conduct the extinguishing agent from a bottom portion of the reservoir opposite the neck towards the outlet nozzle, characterized by the causes a wall of said reservoir to carry an internal rib of helical shape, the winding axis of which is substantially parallel to said dip tube.
• said neck has an internal thread for fixing said ejection device by screwing.
• a fixing is more resistant to the internal ejection pressure than in the case of a thread on the outside of the neck.
• At least one external accessory molded projecting from an external surface of said wall of the tank.
• Such an accessory can for example be a handle, a fixing lug, a stabilizing lug, a transport support or a reinforcement piece. Storage and handling of the extinguisher can thus be facilitated.
• At least one external handle molded hollow in said wall of the tank.
• the wall thickness of the tank is chosen according to the material, shape and working pressure of the fire extinguisher.
• the helical rib offers the advantage of reinforcing the resistance of the reservoir without the need to increase the thickness of the entire wall. This results in a safety gain, a saving of material and a weight saving.
• said tank wall has a thickness of between 3 and 5 mm. It is thus possible to use an internal working pressure greater than 50 bar for example.
• the reservoir can be obtained in any form that can be produced by molding with bi-orientation.
• the tank has a polygonal cross section, which facilitates the adaptation of the extinguisher to a reduced accommodation space, for example in a vehicle.
• the extinguishing agent is a powder or water with one or more additives.
• the reservoir is capable of being obtained by a molding process with bi-orientation, advantageously without preform, comprising steps of coating a movable punch carrying a helical groove and blowing.
• An advantage of such tank is that it does not present any weld, so that its resistance to pressure is improved.
• FIG. 2 is an enlarged detail view of part of the accumulator of FIG. 1, the accumulator being associated with an injection station,
• FIG. 3 is a view similar to FIG. 1, showing an extrusion step by coating a punch
• FIG. 4 is a view similar to FIG. 3, showing a step of bi-orientation with pre-blowing,
• FIG. 5 is a view similar to FIG. 4, showing the end of the blowing step
• FIG. 6 is an enlarged detail view of a manufacturing device according to a second embodiment, the accumulator being associated with a molding station,
• FIG. 9 represents a portable fire extinguisher according to the invention, the reservoir of which can be obtained using the device of FIG. 6.
• the machine comprises an accumulator 1 which is mounted on a mobile support so that it can be associated with two different work stations.
• the accumulator 1 is associated with a molding station 2.
• an accumulation space 12 which extends to the outlet opening 6 and which comprises an annular space closed at its upper end 15 by a extrusion piston 14.
• the extrusion piston 14, the inner jacket 8, the compaction sleeve 9, the calibration sleeve 10 and the central hollow rod 11 are shown in a position of withdrawal from the inside the outer casing 3.
• the central rod 11 has a central duct 17 which is connected at the upper end to a source of pressurized air not shown and which is closed at the lower end by a valve tared 18 recalled to position closing by a spring 19.
• the conduit 17 makes it possible to realize the bi-orientation by blowing.
• the accumulator 1 is shown associated with the other work station, which is an injection station 16.
• the production cycle for a hollow body begins at this station, as will now be explained.
• a screw injection press of known type is used to bring a thermoplastic resin in a malleable state and inject it into the accumulation space 12.
• FIG. 2 only shown an end portion of the injection nozzle 20 which fits snugly against the outer casing 3 of the accumulator 1.
• a predetermined quantity of resin 35 is thus injected into the accumulator 1 so as to fill the accumulation space 12.
• the temperature in the accumulation space 12 is regulated by means of an electrical resistance 21 and a circulation of fluid in the circuit of the inner jacket 8.
• step 22 the accumulator 1 is moved by the rotary support plate to the molding station with bi-orientation 2, visible in Figures 1 and 3 to 5.
• a cover (not shown) closes the opening 6 during this displacement.
• the material contained in the accumulation space 12 is not shown.
• step 30 represents the displacement of the extrusion piston 14 to push the resin out of the accumulation space 12 through the opening 6.
• Step 32 represents the displacement of the parts of the central core 7.
• Step 33 represents the pre-blowing of a low air pressure through the duct 17.
• Step 34 represents the transfer of material through the extrusion orifice 28.
• step 32 the central rod 11 is first moved, which engages through the extrusion die 25 in the mold 24, coated with a regular layer of resin 38.
• the advancement of the central rod 11 takes place at a speed twice the speed of exit of the resin 35 through the extrusion orifice 28, which produces an axial stretching of the resin layer 38 and a corresponding molecular orientation .
• An end portion of the central rod 11 carries a helical groove 39 on its peripheral surface, which prints a corresponding helical rib on the interior surface of the resin layer 38, as visible in FIG. 3.
• the resin layer 38 detached from the rod 11 is shown in Figure 4, in which the helical rib 40 is also shown.
• the resin layer 38 does not come into contact with the peripheral wall of the cavity 36.
• the calibration sleeve 10 is also moved towards the extrusion orifice 28 The calibration sleeve 10 enters the air gap between the rod 11 and the peripheral wall of the extrusion orifice 28.
• the calibration sleeve 10 has an external thread 41, better visible in FIG.
• the calibration sleeve 10 moves to the level of the throttling portion 37 of the mold 24, so as to form an internal thread in the neck of the hollow body during manufacture.
• the ratio between the internal radius of the extrusion orifice 28 and the air gap is approximately 10. While the rod 11 ends its movement up to the bottom wall 42 of the internal cavity 36, the piston 14 and the inner jacket 8 move until they touch the rim 5 to completely empty the accumulation space 12.
• the compaction sleeve 9 slides in an adjusted manner between the calibration sleeve 10 and the peripheral wall of the extrusion orifice 28 up to the lower end of extrusion orifice 28, so as to completely expel the resin from the extrusion die 25 and to compress the material in the gap between the calibration sleeve 10 and the throttling portion 37.
• the end position of the different parts at the end of step 32 is shown in FIG. 5.
• the blowing step 43 is carried out with a higher air pressure, which transversely expands the resin layer 38 until it contacts the walls of the internal cavity 36 and thus completes the bi-orientation.
• molecular weight of the material and the formation of a hollow body 50 for example, the blowing ratio, that is to say the ratio between the diameter of the extruded parison and the diameter of the hollow body 50, is approximately 3/4 .
• step 44 is carried out of returning the extrusion piston 14 to the withdrawn position and then step 45 of returning the parts of the central core 7 to the withdrawn position.
• the parison is supported until its finalization.
• step 45 the calibration sleeve 9 is rotated so as to unscrew its external thread 41 from the corresponding thread formed on the internal surface of the resin layer 38.
• the central rod 11 is coupled to a motor electric rotary numerical control and the calibration socket 9 is coupled to the central rod 11 by a unidirectional ratchet transmission 66, which allows the drive of the calibration socket 9 in the unscrewing direction and also allows the calibration socket 9 to rotate faster than the central rod 11, which avoids forcing on the molded thread when removing the calibration sleeve 9.
• Step 46 represents the closing of the closure cap of the opening 6.
• the step 47 represents cooling from the hollow body 50 to and below the glass transition temperature of the material.
• Step 48 represents the corresponding plasticization phenomenon of the hollow body 50.
• step 49 represents the opening movement of the mold 24 to eject the finished hollow body 50.
• step 51 represents the unlocking of the turntable and step 52 the displacement of the turntable to bring the accumulator 1 to the injection station 16.
• step 52 is in fact an iteration of step 22 which devisates a new cycle which will be executed identically to that which has just been described, with another accumulator 1 previously filled.
• Step 53 represents the corresponding initialization of the machine control module. As shown in Figure 8, the work cycle at station 2 lasts for approximately 15 s.
• the hollow body 50 obtained by the process which has just been described has a regular wall thickness, a helical rib 40 on its internal surface, which reinforces its resistance to pressure, and an internal thread in its neck.
• Other forms of ribs can be obtained in a similar way, adapting the layout of the grooves or on the rod 11.
• a plurality of parallel annular peripheral grooves 5 makes it possible to obtain a plurality of parallel annular ribs in the hollow body 50, and parallel axial grooves make it possible to obtain axial ribs in the hollow body 50.
• step 32 the ratio between the speed of the central rod 11 and the speed of exit of the resin 35 through the extrusion orifice 28 controls the rate of axial elongation of the resin layer 38 and can be chosen according to the desired properties. This rate is equal to 2 in the example described above.
• FIG. 6 a second embodiment of the manufacturing process and a corresponding variant of the molding machine will now be described.
• the same reference numbers are used to designate elements identical or analogous to those of the first embodiment.
• the internal cavity 36 has a shoulder face 54 at right angles to the wall of the throttling portion 37.
• FIG. 6 also shows annular conduits 55 for the circulation of a heat transfer fluid in the extrusion die 25 and in the throttling portion 37, in order to regulate the temperature of the resin in these areas.
• the resin layer 38 is pressed against the walls of the cavity 36 from the bottom to the top of the mold.
• the right half of FIG. 6 represents the resin layer 38 substantially as it is obtained during the blowing step 43 in the first embodiment.
• the calibration sleeve 10 and the compacting sleeve 9 continue to be moved together towards the interior of the mold 24 during the blowing.
• a section 56 of the resin layer 38 which is adjacent to an end portion 58 hooked to the calibration sleeve 10, is driven at a distance from the shoulder face 54 and thus folds back towards a lower portion 57 of the resin layer 38, which is hooked to the peripheral wall of the cavity 36.
• the panel 56 remains more flexible than the rest of the resin layer 38 because the absence of contact with the mold 24 and the coating punch slows down its cooling.
• the left half of FIG. 6 represents, at number 56a, the face as it is approximately positioned when the sockets 9 and 10 arrive at the end of the race.
• the compaction sleeve 9 also sweeps the throttling portion 37 of the blow mold 24 and the threaded part of the calibration sleeve 10 enters the main cavity of the mold 24.
• the blowing is finished with higher pressure, which folds the folded pan against the end portion 58, as shown in Figure 56b, forming a bend of material. This gives a neck with a double wall and an internal thread.
• Large capacity hollow bodies for example 200 liters, can be produced.
• the thickness of the wall is adjusted by the dimension of the air gap existing around the central rod 11 in the extrusion orifice 28.
• FIG. 7 an alternative embodiment of the central rod 11 has been shown, in which the latter has two portions 11a and 11b having a reduced diameter compared to the remainder of the rod 11, to form by coating a parison having a staggered thickness and thus obtain a hollow body having a peripheral wall staggered as to its thickness and / or its diameter.
• the thinned portions 11a and 11b thus make it possible to obtain an extra thickness of the walls at the bottom and at the top of the hollow body 50, which are the areas where the greatest pressure is exerted when the hollow body is used as a pressurized tank.
• FIG. 9 shows a hollow body obtained using the device according to the second embodiment described and used as a reservoir 60 of a portable fire extinguisher 61.
• the reservoir 60 is for example made of a polymer resin crosslinked by ionic bonds known under the registered trademark Surlyn® and manufactured by the company DuPont®. This material has excellent transparency, high scratch resistance, a wide range of processing temperatures and very good resistance to organic solvents.
• the wall 62 has a substantially uniform thickness e being between 3 and 5 mm, to contain a pressure of 55 bar. Its inner surface carries a helical rib 63 having for example a height of about 1 mm.
• the neck 64 of the reservoir 60 has a double wall and an internal thread 68 for screwing an ejection device 65.
• the ejection device 65 comprises a hollow socket 73, the lower portion of which has a thread suitable for screwing into the internal thread 68 of the neck 64.
• a peripheral flange 74 bears against the upper surface 75 of the tank 60 in the assembled state .
• the sleeve 73 has an internal bore 76 in which a pusher 77 provided with a seal 78 slides in leaktight manner.
• a fixed handle 79 is fixed to the top of the socket 73.
• An ejection control lever 81 is also fixed to the top of the socket 73 tilting around an axis 82. A lower surface of the lever 81 bears on the top of the pusher 77.
• a dip tube 69 is fitted to the socket 73 and extends from the lower end of the latter to a bottom portion 80 of the tank 60, in the vicinity of the bottom wall 84.
• a transverse support 85 is arranged mid-length of the tube 69 in its internal section.
• a first cartridge of pressurized gas 86 for example carbon dioxide, is placed in the tube 69 bearing between the pusher 77 and the support 85 by means of a compression spring 92.
• a second cartridge of pressurized gas 87 is placed in the tube 69 in abutment between the support 85 and a rib 88.
• a drilling insert 89 is disposed in the support 85 with two cutting ends oriented along the axis A of the tube 69 towards respective sealing caps of the cartridges 87 and 86.
• Fire extinguisher 61 is a portable, single-use fire extinguisher, the operation of which is explained below.
• Figure 9 shows the state of the fire extinguisher ready for use.
• the extinguishing agent contained in the tank 60 is not shown.
• the lever 81 is lowered manually towards the handle 79, which pushes the pusher 77 against the bottom of the cartridge 86.
• the cartridge 86 comes into contact with the insert 89 which pierces its sealing cap and thus releases the gas under pressure.
• the movement of the cartridge 86 continues by pushing the insert 89 against the sealing cap of the cartridge 87 to also pierce it.
• the gas under pressure for example at 55 bar, is concentrated at the top of the tank 60 by density difference and exerts on the extinguishing agent, for example a powder, a pushing force directed generally towards the bottom portion 80 of the reservoir, as represented by the arrow P.
• the extinguishing agent is pushed towards the end opening 90 of the dip tube and is simultaneously entrained in a swirling movement around the tube 69 due to the orientation of the rib 63, the winding axis of which coincides with the axis A of the tube 69.
• the extinguishing agent rises the tube 69, crosses the support 85 by passages 91 located outside the plane of FIG.
• the shape of the tank 60 can be chosen at will by adapting the shape of the blow mold.
• the cross section of the tank 60 can be circular or polygonal. Ergonomic shapes are produced in the same way in the wall of the tank 60, such as a hollow handle 71 and a projecting tab 72, in order to obtain a complete finish of the fire extinguisher tank according to its use.
• the fire extinguisher 61 can also be of the permanent pressure type without the need to modify the tank 60.
• the plastic material of the tank 60 can also be dyed, in particular in accordance with fire safety standards.

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• Health & Medical Sciences (AREA)
• Public Health (AREA)
• Business, Economics & Management (AREA)
• Emergency Management (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 2003
  • 2003-02-07 FR FR0301448A patent/FR2850875B1/fr not_active Expired - Lifetime
• 2004
  • 2004-02-03 US US10/544,132 patent/US20060131034A1/en not_active Abandoned
  • 2004-02-03 CN CN200480003609A patent/CN100589855C/zh not_active Expired - Fee Related
  • 2004-02-03 EP EP04707550A patent/EP1590049A1/de not_active Withdrawn
  • 2004-02-03 WO PCT/FR2004/000236 patent/WO2004078263A1/fr not_active Ceased

Non-Patent Citations (1)

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