Fuse, thermal release including such a fuse, mounting template for assembling such a fuse and method for mounting such a fuse

Abstract

A fuse, a thermal trip unit comprising such a fuse, a mounting jig for assembling such a fuse, and a method for assembling such a fuse. A thermal trip fuse (10) comprises a bulb (12) containing a liquid and two plates (14A, 14B), each comprising a thermal trip attachment end, a sliding portion, an escape portion, and a retaining end having two retaining tabs. When the fuse is assembled, the bulb extends between the retaining ends of the two plates by being received into receiving elements on the retaining ends of the two plates. Furthermore, the sliding portion of each plate is located between the two retaining tabs of the other plate.The second plate is movable in translation relative to the first plate, along an axis parallel to the sliding portions of the plates, the bulb blocking a translation of the second plate in a direction that brings the retaining end of the second plate closer to the retaining end of the first plate. Figure for the abbreviation: 2.

Description

Title of the invention: Fuse, thermal trigger comprising such a fuse, mounting jig for assembling such a fuse and method for mounting such a fuse

[0001] The present invention relates to a thermal trigger fuse, a thermal trigger comprising such a fuse, a mounting jig for assembling such a fuse and a method for mounting such a fuse.

[0002] In the field of fire detection devices, it is known to use a thermal trigger equipped with a fuse to detect the occurrence of a fire and to automatically trigger firefighting means when a fire is detected.

[0003] A wide variety of thermal triggers exist.

[0004] For example, it is known to use a fixed automatic water extinguishing system, also called a sprinkler, which comprises extinguishing heads connected to water pipes. Each extinguishing head includes a bulb that is compressed between a valve closing a water pipe and a retaining element. This compression is caused by the water pressure contained in the pipe, which presses on the valve and thus on the bulb. A temperature rise in the bulb above a predetermined threshold causes it to rupture, which releases the valve and opens the water pipe, allowing the sprinkler to be activated.

[0005] The use of such bulbs is particularly effective, as it is simple and inexpensive. However, such bulbs are particularly suitable for operation in compression, i.e. to prevent two parts from coming together, such as the valve and the retaining element in the case of a sprinkler, but are not intended to operate in tension, i.e. to prevent two parts from moving apart.

[0006] To overcome this limitation, US 5,927,890 A proposes a fuse comprising a bulb held between two connecting pieces. Each connecting piece has a hook eye from which two tabs extend, each tab encircling one end of the bulb. The two connecting pieces are hooked to each other. When a tensile force is applied to the fuse via the two hook eyelets, the bulb is compressed between the tabs of the two connecting pieces, preventing the two pieces from being released. When the bulb bursts, due to intense heat, the tensile force applied to the fuse causes the two connecting pieces to separate. This fuse therefore allows the use of a bulb in a fuse operating under tension, but presents a The technical limit is a significant tensile stress. Excessive tensile stress on the fuse can cause it to break, either by the bulb bursting or by deforming the connecting parts. Such an unexpected break could trigger a fire suppression system even if there is no fire.

[0007] FR-A-3 052 362 A proposes an alternative fuse to overcome this limitation. This fuse comprises a bulb, two tensioned stirrups, and a free-moving part. Each of the two stirrups has an eyelet for applying tensile force to the fuse, and when the fuse is assembled, the relative movement of the two stirrups is prevented by the free-moving part, which is held in place by the bulb and by shafts connected to each of the two stirrups. Although more robust than the fuse of US 5 927 890 A, this fuse has several drawbacks: upon tripping, the free-moving part is ejected from the fuse and can therefore strike people or equipment in the vicinity, which is dangerous. In addition, this fuse requires the use of a large number of parts and is complex; its manufacture is therefore expensive.Furthermore, the fuse forms a cage surrounding the bulb, so that after the bulb breaks, fragments of the bulb can block the relative movement of the two brackets and prevent a device connected to the fuse from tripping. Finally, this fuse is not suitable for use in aggressive environments, as the two brackets and the freely moving part have significant contact surfaces, increasing the risk of corrosion and jamming between these parts.

[0008] It is these drawbacks that the invention intends to remedy in particular, by proposing a fuse operating in tension and using a bulb, which is both robust, reliable and inexpensive.

[0009] To this end, the invention relates to a thermal release fuse, comprising: - a bulb containing a liquid, having a first end and a second end, the bulb being configured to break when the liquid contained in the bulb reaches a predetermined temperature, - a first plate and a second plate.

[0010] According to the invention, each of the first and second plates comprises: • a hooking end, configured to allow the plate to be hooked to a hooking element of a thermal trigger; • a sliding portion, connected to the hook end and having a flat shape extending along a sliding axis; • an exhaust portion, connected to the sliding portion; and • a retaining end, connected to the exhaust portion and comprising a receiving element and two retaining tabs.

[0011] Furthermore, in the assembled configuration of the fuse: - the bulb extends between the retaining end of the first plate and the retaining end of the second plate; - the receiving organ of the retaining end of the first plate receives the first end of the bulb; - the receiving organ of the retaining end of the second plate receives the second end of the bulb; - the sliding portion of the first plate is located between the two retaining tabs of the retaining end of the second plate; - the sliding portion of the second plate is located between the two retaining tabs of the retaining end of the first plate; - the second plate is movable in translation relative to the first plate along an axis of translation parallel to the sliding axis of the sliding portion of the first plate and parallel to the sliding axis of the sliding portion of the second plate; and - the bulb blocks a translation of the second plate along the axis of translation in a direction of approaching the retaining end of the second plate relative to the retaining end of the first plate.

[0012] Thanks to the invention, the plates exert a tensile force on the bulb, which improves its resistance and prevents the fuse from tripping unintentionally. Furthermore, the first and second plates are simple to manufacture, thus reducing the cost of fuse production, and have small contact surfaces with each other, which limits the risk of the plates jamming. In addition, each plate is designed to be attached to a latching element of the thermal trip unit, preventing parts from being ejected when the fuse trips. The design of the first and second plates also ensures simple and reliable fuse tripping.

[0013] According to other advantageous aspects of the invention, the fuse comprises one or more of the following features, taken individually or in all technically possible combinations:

[0014] - The fuse further comprises a fixing piece and, in assembled configuration of the fuse, the fixing piece is fixed to the first plate and blocks a translation of the second plate along the axis of translation in a direction away from the retaining end of the second plate relative to the retaining end of the first plate.

[0015] - The receiving element for the retaining end of the second plate is a receiving hole and, in the assembled configuration of the fuse, the second end of the bulb extends through the receiving member of the retaining end of the second plate and passes through the retaining end of the second plate, and the retaining piece covers the receiving member of the retaining end of the second plate and surrounds the second end of the bulb.

[0016] - A distance separating the two retaining tabs of the first plate, measured perpendicular to the sliding axis of the first pad, is less than a width of the sliding portion of the second pad, measured perpendicular to the sliding axis of the second pad and greater than a width of the escape portion of the second pad, measured perpendicular to the sliding axis of the second pad, and a distance separating the two retaining lugs of the second pad, measured perpendicular to the sliding axis of the second pad, is less than a width of the sliding portion of the first pad, measured perpendicular to the sliding axis of the first pad and greater than a width of the escape portion of the first pad, measured perpendicular to the sliding axis of the first pad.

[0017] - Each of the first and second plates further comprises a portion of clearance, located between the escape portion and the retaining end of the pad, comprising two clearance walls extending in a plane inclined relative to the sliding axis of the pad. A width of the clearance portion of the first pad, measured perpendicular to the sliding axis of the first pad at the level of the clearance walls of the first pad, is greater than the distance separating the two retaining tabs of the second pad, and a width of the clearance portion of the second pad, measured perpendicular to the sliding axis of the second pad at the level of the clearance walls of the second pad, is greater than the distance separating the two retaining tabs of the first pad.

[0018] - For each of the first and second plates, the retaining end has a planar shape and an angle formed between the sliding portion and the retaining end is strictly greater than 90°, preferably between 100° and 110°.

[0019] - For each of the first and second plates, the hook end presents a flat shape and forms an angle with the sliding portion between 158° and 160°, and in which, preferably, in the assembled configuration of the fuse, the hook end of the first plate and the hook end of the second plate extend in the same hook plane.

[0020] - The first plate is identical to the second plate.

[0021] According to another aspect, the invention also relates to a thermal trigger

[0022]

[0023]

[0024]

[0025]

[0026] including: - a compressed gas cartridge, - a triggering element, configured to strike the compressed gas cartridge when triggered, - a base and - a fuse according to any one of claims 1 to 8, the hook end of one of the plates between the first plate and the second plate being hooked to the base and the hook end of the other of the plates between the first plate and the second plate being hooked to the triggering element The fuse is configured for: - prevent the triggering element from being activated when the bulb is intact and - trigger the triggering element when the bulb breaks. This thermal trigger induces the same advantages as those mentioned above regarding the fuse of the invention. According to another aspect, the invention also relates to a mounting jig for assembling a fuse as described above, comprising: - retaining elements, configured to hold the first plate and the second plate in position on the mounting template while allowing a translation of the first plate along the translation axis aimed at bringing the retaining end of the first plate closer to the retaining end of the second plate; - a bulb holder, configured to receive the bulb and position the bulb between the retaining ends of the first and second plates and between the sliding portions of the first and second plates; and - a protrusion, configured to position the fixing piece in contact with the first plate. This mounting template induces the same advantages as those mentioned above regarding the fuse of the invention. According to another aspect, the invention also relates to a method for mounting a fuse as described above using the mounting jig described above, the method comprising at least the following steps: - assemble the first plate with the second plate, positioning the two retaining tabs of the first plate at the exhaust portion of the second plate and positioning the two retaining tabs of the second plate at the exhaust portion of the first plate, then by moving the second plate relative to the first plate along the translation axis so as to move the retaining end of the second plate away from the retaining end of the first plate; - position the first plate and the second plate on the mounting template; - position the bulb on the mounting template, preferably on the bulb holder, placing the first end of the bulb opposite the receiving element of the retaining end of the first plate and placing the second end of the bulb opposite the receiving element of the retaining end of the second plate; - move the first plate relative to the second plate along the translation axis so as to bring the retaining end of the first plate closer to the retaining end of the second plate until the bulb blocks the movement of the first plate; - Position the fixing piece on the mounting template; and - attach the fixing piece to the first plate.

[0027] This assembly method induces the same advantages as those mentioned above with regard to the fuse of the invention.

[0028] The invention will become clearer upon reading the following description, given solely by way of non-limiting example and with reference to the drawings in which:

[0029] [Fig-1] The [Fig. 1] is a partial perspective view of a thermal trigger according to the invention.

[0030] [Fig.2] The [Fig.2] is a perspective view of a fuse according to the invention, the fuse belonging to the thermal trigger of the [Fig.1].

[0031] [Fig.3] The [Fig.3] is an exploded perspective view of the fuse of the [Fig.2].

[0032] [Fig.4] Fig.4 is a top view of a plate belonging to the fuse of the figures 2 and 3.

[0033] [Fig.5] The [Fig.5] is a series of side views of the fuse of figures 2 and 3, illustrating, on several insets A) to D), several phases of the fuse rupture.

[0034] [Fig.6] Fig.6 is a perspective view of a mounting jig according to the invention.

[0035] [Fig.7] The [Fig.7] is a perspective view of the mounting jig of the [Fig.6], on which the fuse of figures 2 and 3 is mounted.

[0036] A thermal trigger 1, also called a pneumatic thermal trigger, is visible in [Fig. 1]. The thermal trigger 1 includes a base 2, which has a hook 3. The base 2 also allows the thermal trigger 1 to be attached to an unrepresented medium.

[0037] The thermal trigger further comprises a compressed gas cartridge 4 and a triggering element 5. Here, the triggering element 5 comprises a support piece 6, which is fixed relative to the base 2, a piston 7, which is movable relative to the support piece 6, and a spring 8. The compressed gas cartridge is connected to an outlet fitting 9, intended to be connected to a pneumatic circuit. In the configuration shown in [Fig. 1], the compressed gas cartridge is sealed. The expansion of the gas contained within it and its flow towards the outlet fitting 9 are prevented.

[0038] In [Fig.1], the support piece 6 and the base 2 are partially torn away to reveal the piston 7 and the spring 8, which are normally hidden, being arranged inside the support piece 6.

[0039] The thermal trigger further includes a bulb fuse 10. The fuse 10 is attached on one side to the hook 3 and on the other side to the piston 7. The spring 8 exerts an elastic force on the piston 7, which aims to move the piston 7 away from the hook 3, towards the compressed gas cartridge 4. The presence of the fuse 10 prevents this movement of the piston. In other words, the fuse 10 holds the piston 7 in position, against the force exerted by the spring 8, that is to say, it prevents the triggering element 5 from being activated. The fuse 10 is thus subjected to a tensile force between the hook 3 and the piston 7.

[0040] The fuse 10 is designed to release the piston 7 when it reaches a predetermined temperature, as explained in more detail below. When this predetermined temperature is reached, the fuse 10 breaks, and the piston 7 is then set in motion by the spring 8. It then strikes the compressed gas cartridge 4, breaking its seal and allowing the gas contained within it to expand and flow towards the outlet fitting 9. The triggering element 5 is then said to have been triggered, this triggering being caused by the fuse 10. Thus, the fuse reaching the predetermined temperature triggers the triggering element 5, the opening of the compressed gas cartridge 4, and the supply of the compressed gas cartridge to the pneumatic circuit.

[0041] The thermal trigger 1 can be used in various fire-fighting installations to, on the one hand, detect the start of a fire and, on the other hand, activate fire-fighting equipment.

[0042] For example, the thermal trigger can be integrated into an automatic fire suppression system, in which, after the thermal trigger is activated, the gas contained in the compressed gas cartridge 4 is used to pressurize an extinguishing agent contained in a tank. This type of automatic fire suppression system is commonly used in fuel distribution areas to extinguish any outbreak of fire without requiring human intervention.

[0043] Fuse 10 is now described in more detail, with reference to figures 2 to 5.

[0044] The fuse 10 includes a bulb 12 having a first end 12A and a second end 12B extending along a bulb axis XI2. As best seen in [Fig. 3], the first end 12A of the bulb has a rounded shape, for example, a hemisphere, while the second end 12B of the bulb has a tapered shape, for example, a point. The bulb contains a liquid, for example, alcohol, and is designed to break when this liquid reaches a predetermined temperature. In practice, as the temperature rises, the liquid expands and exerts pressure on the bulb, causing it to break.

[0045] The predetermined temperature is, for example, set at 68°C. Alternatively, this temperature may be different, generally being set at a value between +57°C and 260°C.

[0046] Fuse 10 comprises a first plate 14A and a second plate 14B.

[0047] The first plate 14A includes a latching end 16A, which is, in the example, planar. The 16A attachment end includes an 18A attachment hole, which allows the first 14A plate to be attached to the thermal trigger 1 and a 20A fixing hole.

[0048] The first plate 14A includes a sliding portion 22A, which is adjacent, i.e. connected, to the hook end 16A. The sliding portion 22A has a planar shape extending along a sliding axis X22A. Advantageously, the sliding portion 22A has a rectangular shape, extending over a length L22 preferably between 9.45 mm and 9.85 mm, measured parallel to the sliding axis X22A and over a width L22 preferably between 12.80 mm and 13.20 mm, measured perpendicular to the sliding axis X22A.

[0049] Advantageously, the hook end 16A is inclined relative to the sliding portion 22A, i.e., the hook end forms an angle [3] with the sliding portion. The angle [3] is preferably between 158° and 160°.

[0050] The first plate 14A comprises an exhaust portion 24A, which is adjacent, i.e., connected, to the sliding portion 22A. The exhaust portion 24A has a planar shape extending along the sliding axis X22A. In other words, the exhaust portion extends in continuity with the sliding portion. Advantageously, the exhaust portion 24A has a rectangular shape, extending over a length L24 preferably between 3.30 mm and 3.39 mm, measured parallel to the sliding axis X22A, and over a width L24 preferably between 8.62 mm and 8.65 mm, measured perpendicular to the sliding axis X22A.

[0051] The first plate 14A includes a clearance portion 26A, which is adjacent, i.e. connected, to the exhaust portion 24A. The clearance portion has a planar shape extending along the sliding axis X22A. In other words, the clearance portion extends in continuity with the sliding and exhaust portions.

[0052] The first plate 14A comprises two clearance walls 28A, which extend from the clearance portion 26A along an inclined plane P28A with respect to the sliding axis X22A of the first plate, i.e. the clearance walls 28A form an angle o with the clearance portion 26A. The angle o is preferably between 108° and 110°.

[0053] In practice, the two clearance walls 28A are formed at the end of the clearance portion 26A connected to the exhaust portion 24A, on either side of the clearance portion.

[0054] Advantageously, the clearance portion 26A has a rectangular shape, extending over a length L26 preferably between 8.40 mm and 8.60 mm, measured parallel to the sliding axis X22A and over a width / 26 preferably between 18.80 mm and 19.20 mm, measured perpendicular to the sliding axis X22A at the clearance walls 28A.

[0055] The first plate 14A includes a retaining end 30A, which is adjacent, i.e. connected, to the release portion 26A. The retaining end 30A has a flat shape. Advantageously, the retaining end 30A has a rectangular shape, extending over a length L30 preferably between 14.10 mm and 14.40 mm and over a width L30 preferably between 18.7 mm and 19.30 mm.

[0056] The retaining end 30A is inclined relative to the clearance portion 28A, i.e., the retaining end forms an angle α with the clearance portion. The angle α is strictly greater than 90° and is preferably between 100° and 110°.

[0057] The retaining end 30A comprises a receiving member 32A, which in this example is a receiving hole, and two retaining tabs 34A. The two retaining tabs 34A are, in practice, formed at the free end of the retaining end 30A, i.e., opposite the clearance portion 26A, and are spaced apart by a width of / 34, preferably between 9.00 mm and 9.20 mm. The two retaining tabs 34A form a retaining volume 36A with a width of / 36, preferably between 13.30 mm and 13.70 mm. The two retaining tabs 34A are hook-shaped, so that the width / 36 is greater than the width / 34.

[0058] Furthermore, the width / 22 of the sliding portion 22A is greater than the width / 34 separating the two retaining tabs 34A and is less than the width / 36 of the retaining volume 34A; the width / 24 of the exhaust portion 24A is less than the The width / 34 separating the two retaining tabs 34A is less than the width / 36 of the retaining volume 34A; and the width / 26 of the clearance portion 26A is greater than the width / 34 separating the two retaining tabs 34A and less than the width / 36 of the retaining volume 34A. Furthermore, the width / 24 of the exhaust portion 24A is less than the width / 22 of the sliding portion 22A, which is itself less than the width / 26 of the clearance portion 26A and the width / 30 of the retaining end 30A. Preferably, the width / 26 of the clearance portion 26A is equal to the width / 30 of the retaining end 30A.

[0059] The second plate 14B comprises a hooking end 16B, with a hooking hole 18B and a fixing hole 20B; a sliding portion 22B extending along a sliding axis X22B; an escape portion 24B; a clearance portion 26B; two clearance walls 28B; a retaining end 30B with a receiving member 32B and two retaining tabs 34B. In practice, the second plate 14B is similar to the first plate 14A.

[0060] Advantageously, as in the example in the figures, the second plate 14B is identical to the first plate 14A, which simplifies the manufacture of the fuse 10 and reduces its cost. Thus, the dimensions and arrangements of the latching and retaining ends and the sliding, escape, and release portions of the second plate are identical to those of the first plate.

[0061] The fuse 10 further includes a fixing piece 38, which in the example is S-shaped. The fixing piece 38 includes a fixing portion 40, which is essentially flat and has a fixing hole 42, and a protective portion 44, which is C-shaped.

[0062] As seen in [Fig.2], in the assembled configuration of the fuse, the first plate 14A and the second plate 14B are assembled together and the bulb 12 is held between the first plate 14A and the second plate 14B.

[0063] More specifically, in the assembled configuration of the fuse: - The sliding axis X22A of the sliding portion 22A of the first plate 14A is parallel to the sliding axis X22B of the sliding portion 22B of the second plate 14B. - The retaining end 30A of the first plate 14A extends parallel to the retaining end 30B of the second plate 14B. - The bulb 12 extends between the retaining end 30A of the first plate 14A and the retaining end 30B of the second plate 14B. - The 32A receiving hole of the 30A retaining end of the first 14A plate receives the first 12A end of the bulb 12. In practice, the 32A receiving hole has a diameter adapted so that the first end 12A of bulb 12 is partly received in the receiving hole, without being able to pass through the receiving hole. The receiving hole 32B of the retaining end 30B of the second plate 14B receives the second end 12B of the bulb. In practice, the receiving hole 32A has a diameter adapted so that the second end 12B of the bulb 12 passes through the receiving hole, without allowing the bulb to pass completely through the receiving hole. Thus, the second end of the bulb passes through the retaining end 30B of the second plate 14B. - The sliding portion 22A of the first plate 14A is engaged between the two retaining tabs 34B of the retaining end 30B of the second plate 14B. In other words, the sliding portion 22A is received in the retaining volume 36B and is surrounded by the retaining tabs 34B. - The sliding portion 22B of the second plate 14B is engaged between the two retaining tabs 34A of the retaining end 30A of the first plate 14A. In other words, the sliding portion 22B is received in the retaining volume 36A and is surrounded by the retaining tabs 34A.

[0064] It is understood that, in the assembled configuration of the fuse 10, the first plate 14A and the second plate 14B are interlocked, which limits the possible relative movements between the two plates. In practice, a translation of the second plate relative to the first plate perpendicular to the sliding axis X22A, or a rotation of the second plate around the sliding axis X22A, is prevented by the shape cooperation between the sliding portion 22B and the retaining tabs 34A. Thus, the second plate 14B is only movable in translation relative to the first plate 14A along the sliding axis X22B. Similarly, the first plate is only movable in translation relative to the second plate along the sliding axis X22A.

[0065] A translation axis X22 of the plates 14A and 14B is defined as an axis parallel to the sliding axis X22A of the sliding portion of the first plate, parallel to the sliding axis X22B of the sliding portion of the second plate and located halfway between the axes X22A and X22B.

[0066] Furthermore, in the assembled configuration of the fuse, the bulb 12 blocks a translation of the second plate 14B along the translation axis X22, in a direction of approaching the retaining end 30B of the second plate to the retaining end 30A of the first plate, since the bulb extends between the retaining ends of the two plates.

[0067] As can be seen in [Fig. 5], the translation axis X22 forms an angle θ with the bulb axis X12. The angle θ is preferably between 10° and 20°. This non- null is particularly advantageous for the positioning of the bulb, as the bulb is perpendicular to the retaining ends 30A, 30B, therefore in an ideal position to resist the compressive forces described below.

[0068] In the assembled configuration of the fuse 10, the fixing piece 38 is fixed to the first plate 14A, by means of a fixing element 46, which in the example is a rivet, which extends into the fixing hole 42 of the fixing piece 38 and into the fixing hole 20A of the first plate 14A. Thus, the fixing part 40 of the fixing piece 38 is pressed against the hook end 16A of the first plate 14A.

[0069] In a non-represented variant of the invention, the fixing piece 38 is fixed to the first plate 14A using other means, such as a screw, glue, or welding.

[0070] Furthermore, in the assembled configuration of the fuse 10, the protective part 44 of the fixing piece 38 covers the receiving hole 32B of the retaining end 30B of the second plate 14B and surrounds the second end 12B of the bulb 12. The second end of the bulb is thus protected from possible shocks, which prevents its accidental breakage.

[0071] In addition, in the assembled configuration of the fuse 10, the protective part 44 of the fixing piece 38 presses on the second plate 14B, so as to block a translation of the second plate along the translation axis X22 in a direction away from the retaining end 30B of the second plate relative to the retaining end 30A of the first plate.

[0072] The fuse 10 is held in the assembled position by means of the bulb 12, which prevents the two plates from moving towards each other, and by means of the retaining piece 38, which prevents the two plates from moving apart. Thus, accidental removal of the fuse is impossible.

[0073] Advantageously, in the assembled configuration of the fuse 10, the latching end 16A of the first plate 14A and the latching end 16B of the second plate 14B extend in the same latching plane P10, which forms an angle y with the translation axis X22. The angle y is preferably between 20° and 22°.

[0074] As can be seen in [Fig.5], the sum of angles y and [3] is equal to 180°.

[0075] We denote by co the angle formed by the clearance wall 28A and the plane P10. This angle co is equal to the sum of angles o and y.

[0076] When the thermal trigger 1 is in the assembled configuration, the hook 3 is attached to the hook hole 18A of the hook end 16A of the first plate 14A and the piston 7 is attached to the hook hole 18B of the hook end 16B of the second plate 14B. In the example, the end of the piston 7 has a slot receiving the hook end 16B and a pin 72 passes through the end of the piston and the hook hole 18B to allow the piston 7 to be fixed to the hook hole 18B.

[0077] The fuse 10 is thus kept under tension by the force exerted by the spring 8 on the piston 7. Two forces F, visible in [Fig. 5], are therefore applied to the gripping ends of the two plates, which are opposite and oriented along a traction axis X10 connecting the two gripping ends. Thus, the traction axis X10 is contained within the gripping plane P10, and the angle co is the angle between the release wall 28A and the axis X10 and between the release wall 28B and the axis X10. These forces F are transmitted by the plates 14A, 14B to the bulb 12. The geometry of the plates 14A, 14B, and more particularly the fact that the bulb is held between the two retaining ends 30A, 30B of the plates, causes the bulb 12 to be subjected to compressive forces.In other words, the fuse plates allow the tensile forces F applied to the latching ends 16A, 16B of the plates to be transformed into compressive forces applied to the bulb. As the bulb 12 is, in a manner known per se, specifically designed to withstand significant compressive forces, the resistance of the fuse 10 to unintentional tripping, linked to a mechanical rupture of the bulb 12, is minimized.

[0078] With reference to [Fig. 5], the fuse rupture process of the fuse 10 is now described. This rupture process begins with the rupture of the bulb 10, illustrated in inset A) of [Fig. 5]. In this phase, the plates 14A, 14B are in their initial position. This rupture occurs when the temperature of the bulb 12 reaches the predetermined temperature, for example, set at 68°C.

[0079] After the bulb 12 breaks, the translational movement of the second plate 14B along the translational axis X22, bringing the retaining end 30B of the second plate closer to the retaining end 30A of the first plate 14A, is no longer blocked by the bulb. In other words, after the bulb breaks, relative movement of the two plates is possible. This movement leads to the release of the fuse 10 and the movement of the piston 7 under the force exerted by the spring 8.

[0080] In a first phase of relative movement of the plates 14A, 14B, the second plate 14B undergoes a translational movement relative to the first plate 14A along the translational axis X22, from the initial position shown in inset A) of [Fig. 5], to a stop position shown in inset B) of [Fig. 5]. Thanks to the angle θ formed between the traction axis X10 and the translational axis X22, the translation of the second plate along the translational axis X22 is effectively driven by the tensile forces F.

[0081] In this abutment position, the retaining end 30B of the second plate is in contact, i.e., abutted, with the clearance walls 28A of the first plate, and the retaining end 30A of the first plate is in contact, i.e., abutted, with the clearance walls 28B of the second plate. This contact between the retaining ends and the clearance walls prevents the second plate from continuing its translational movement relative to the first plate, parallel to the translational axis X22.

[0082] In the stop position, the retaining tabs 34A of the first plate 14A are located at the level of the exhaust portion 24B of the second plate 14B, and the retaining tabs 34B of the second plate are located at the level of the exhaust portion 24A of the first plate. Since the width θ24 of the exhaust portions 24A and 24B is less than the distance θ34 separating the two retaining tabs of each of the two plates, separation, in other words, disassembly, of the two plates is possible. Thus, in the stop position shown in inset B) of [Fig. 5], the two plates are not restricted to a relative translational movement.

[0083] In a second phase of relative movement of the plates 14A, 14B, the two plates are separated from each other. This separation is caused by the tensile forces F, which tend to bring the retaining ends 30A, 30B of the two plates closer together, and by the contact between the retaining end 30A, 30B of each plate with the release walls 28A, 28B of the other plate, which allows the retaining tabs of each plate to be released. More precisely, thanks to the angle formed between the tensile axis X10 and the inclined planes P28A, P28B, the tensile forces F cause the plates 14A, 14B to move away from each other by sliding relative to each other in a direction parallel to the inclined planes P28A, P28B.

[0084] Advantageously, angle a is less than angle o. This choice of angles a and a is particularly advantageous for facilitating the separation of the two plates and, more specifically, the sliding of the retaining end walls 30A, 30B respectively against the release walls 28B, 28A. Indeed, the fact that angle a is less than angle o reduces the risk of the retaining ends jamming against the release walls.

[0085] At the end of this second phase of movement, not shown in [Fig. 5], the two plates are no longer interlocked. In other words, the two plates are no longer attached to each other, even though they are still in contact.

[0086] The inclination of the traction axis X10 with the translation axis X22, corresponding to angle y, on the one hand, and the inclination of the traction axis X10 with the clearance walls 28A, 28B, corresponding to angle co, on the other hand, is particularly useful for enabling the execution of the first and second phases of movement. These inclinations allow for several movements carried by different directions, namely the translation axis for the first phase and the inclined planes of the clearance walls for the second phase, from the forces F exerted along the traction axis X10.

[0087] In a third phase of relative movement of the plates 14A, 14B, the second plate 14B is driven by the force F applied to it in a translational movement along the traction axis X10, bringing the retaining ends 30A, 30B of the two plates closer together. It should be noted that this force F is caused by the spring 8, which drives the movement of the piston 7 and therefore of the second plate 14B, which is attached to the piston.

[0088] This third phase of relative movement of the plates 14A, 14B ends when the retaining ends 30A, 30B of the two plates come into contact. This position is illustrated in inset C) of [Fig. 5].

[0089] In a fourth phase of relative movement of the plates 14A, 14B, the retaining end 30B of the second plate 14B slides relative to the retaining end 30A of the first plate 14A, until it reaches a position where the two plates are no longer in contact, as illustrated in inset D) of [Fig.5].

[0090] This sliding is facilitated by the angle a formed between the retaining ends 30A, 30B and the release portions 26A, 26B and the sliding portions 22A, 22B of the plates and more particularly by the sum of the angles a and y, which allows the force F applied to the second plate to easily slide from the two retaining ends to each other.

[0091] At the end of the fourth phase of movement, the two plates are released from each other, that is to say they are no longer in contact with each other and the movement of the piston 7, driven by the spring 8, is no longer impacted by the fuse 10. The piston 7 can thus strike the compressed gas cartridge 4.

[0092] During the fuse's tripping, the first plate 14A remains attached to the hook 3 and the second plate 14B remains attached to the piston 7. Thus, apart from fragments of the bulb 12, no parts or debris are ejected or released when the fuse 10 trips. This is particularly advantageous for avoiding any risk of injury to an operator or damage to an object located near the fuse 10 at the time of its tripping.

[0093] Furthermore, thanks to the first and second plates 14A, 14B, which are shaped like folded sheet metal and do not form a cage around the bulb 12, the fragments of the bulb are easily expelled from the fuse 10 when the bulb breaks. This prevents fragments of the bulb from becoming stuck between the two plates and preventing the release of the two plates. The de- The triggering of fuse 10 is thus made more reliable and the risks of blockage are minimized.

[0094] A mounting jig 50 is now described with reference to Figures 6 and 7, which facilitates the mounting of the fuse 10. In [Fig.6], the mounting jig is shown alone and in [Fig.7], the fuse 10 is shown in assembled configuration on the mounting jig.

[0095] The mounting jig 50 includes a flat base 52.

[0096] The mounting template includes two studs 54A, 54B, which extend from the flat base and form a groove 54C between them. The groove 54C is designed to receive the hook end 16B of the second plate.

[0097] The mounting jig 50 also includes a platform 56A and a stud 56B, which extend from the flat base 52 and form a groove 56C between them. The groove 56C is provided to receive the retaining end 30B of the second plate.

[0098] Thus, thanks to the grooves 54C and 56C, when the second plate 14B is placed on the mounting template, the positioning of the second plate is controlled and its movement in the plane of the flat base 52 is prevented.

[0099] The mounting jig 50 further includes a stop 58, which extends from the flat base 52. When the first and second plates 14A, 14B are assembled together and placed on the mounting jig 50, the clearance portion 26A of the first plate 14A is in contact with the stop 58, facilitating the retention of the first plate in position on the mounting jig 50.

[0100] The mounting jig 50 further includes a bulb holder 60, which extends from the flat base 52 and has a groove 62. When the two plates 14A, 14B are assembled together and placed on the mounting jig 50, the bulb holder 60 is located between the retaining ends 30A, 30B of the plates and between the sliding portions 22A, 22B of the plates, and the groove 62 extends between the retaining ends of the two plates. In practice, the groove 62 is designed to receive and position the bulb 12 relative to the plates 14A, 14B.

[0101] The mounting jig 50 further includes a protrusion 64, which extends from the platform 56A and which allows the fixing piece 38 to be positioned on the mounting jig 50, as described below.

[0102] Preferably, the platform 56A also has a hole 66, which makes it easier to fix the fixing piece 38 onto the first plate, as explained below.

[0103] Preferably, the mounting template 50 includes fixing holes 68, which allow it to be fixed to a work surface not shown.

[0104] Advantageously, during the assembly of the fuse 10, the clearance portion 26B of the second plate 14B is also in contact with the protrusion 64 of the platform 56A, facilitating the holding of the second plate in position.

[0105] A method for mounting the fuse 10 using the mounting template 50 is now described.

[0106] The assembly method includes a first step consisting of assembling the first plate 14A with the second plate 14B, by placing the two retaining tabs 34A of the first plate at the level of the exhaust portion 24B of the second plate and by placing the two retaining tabs 34B of the second plate at the level of the exhaust portion 24A of the first plate, then moving the second plate relative to the first plate along the translation axis X22 so as to move the retaining end 30B of the second plate away from the retaining end 30A of the first plate.

[0107] Preferably, this first step is carried out without the aid of the mounting template 50. In practice, this first step is carried out manually by an operator, the interlocking of the two plates with each other being facilitated by the geometry of the plates.

[0108] The assembly method includes a second step, which consists of positioning the first plate 14A and the second plate 14B, assembled together, on the mounting jig 50. The positioning of the plates on the mounting jig is facilitated by the grooves 54C, 56C, as well as by the stop 58 and the protrusion 64, which thus form retaining elements for the plates on the mounting jig. The placement of these retaining elements is further designed to allow translation of the first plate 14A along the translation axis X22, thereby bringing the retaining end 30A of the first plate closer to the retaining end 30B of the second plate. In particular, it is noted that the hook end 16A passes over the platform 56A of the mounting jig.

[0109] At the end of this second step, a distance separating the retaining ends 30A, 30B of the two plates is greater than a length L12 of the bulb 12.

[0110] The mounting method includes a third step, which consists of positioning the bulb 12 on the mounting jig 50, more precisely in the groove 62, by placing the first end 12A of the bulb opposite the receiving element 32A of the retaining end 30A of the first plate and by placing the second end 12B of the bulb opposite the receiving element 32B of the retaining end 30B of the second plate. The height of the bulb holder 60 is advantageously provided to allow this positioning of the bulb opposite the receiving elements 32A and 32B.

[0111] The assembly method includes a fourth step, which consists of moving the first plate 14A relative to the second plate 14B along the translation axis X22 so as to bring the retaining end 30A closer to the first the retaining end plate 30B of the second plate until the bulb 12 blocks the movement of the first plate. At the end of this step, the relative positioning of the two plates 14A, 14B corresponds to the positioning visible in [Fig.2] and on insert A) of [Fig.5].

[0112] The assembly method includes a fifth step, which consists of positioning the fastener 38 on the mounting jig 50, between the hook end 16A of the first plate, the retaining end 30B of the second plate, and the protrusion 64 of the mounting jig. The protrusion 64 thus allows the fastener 38 to be positioned in contact with the hook end 16A of the first plate 14A. The positioning of the fastener 38 is therefore controlled. Furthermore, after this positioning, the fixing hole 42 of the fastener 38 is aligned with the fixing hole 20A of the first plate 14A.

[0113] The assembly process includes a sixth step, which consists of attaching the fastener 38 to the first plate 14A. In the example, this attachment is made using the rivet 46, which is a blind rivet. For this purpose, the rivet is inserted through the mounting holes 42 and 20A and is set using a riveting tool. Advantageously, to facilitate this riveting, the shank of an unused blind rivet can be inserted into the hole 66, which allows the fastener 38 to be held in position during the riveting operation.

[0114] At the end of this sixth step, the fuse 10 is assembled and cannot be disassembled without breaking the bulb 12 or without destroying the rivet 46, since the bulb and the fixing piece 38 together prevent any translation of the two plates 14A, 14B intended to move the two retaining ends 30A, 30B of the plates away from or towards each other.

[0115] The installation of the fuse 10 described in the above method is facilitated by the use of the mounting template 50, but this mounting template is not mandatory for installing the fuse. Indeed, this installation can also be carried out manually, or using other mounting devices not described herein.

[0116] In addition, it is also possible to automate the assembly of the fuse 10 with or without the assembly jig 50. For example, a semi-automatic assembly station is set up using the assembly jig 50 to industrialize the assembly of fuses 10. Such a semi-automatic assembly station is preferably complemented by an engraving station, allowing the engraving of batch numbers on the fuses 10 for traceability, and by a unit inspection station using an industrial vision camera, allowing quality control to be carried out to validate the correct assembly of the fuses 10.

[0117] In the example, the first plate 14A and the second plate 14B are each made from a flat sheet, which is stamped to form the walls of clearance 26A, 26B and which is folded to form angles a and [3. Thus, the first and second plates are particularly simple and inexpensive to manufacture, which reduces the cost of fuse 10.

[0118] In a non-represented variant of the invention, the first plate 14A is not fixed to the base 2 by a hook, but by other means, such as for example by a pin or by a bolt.

[0119] In a non-shown embodiment of the invention, the first plate 14A and the second plate 14B are not identical. For example, the second plate 14B does not have a mounting hole 20B, or the attachment ends 16A, 16B of the two plates are different. For example, the attachment ends of the two plates may have different lengths and geometries or different means of attachment to the base 2 and the piston 7.

[0120] Any feature described for an embodiment or variant in the foregoing may be implemented for the other embodiments and variants described above, provided that it is technically feasible.

Claims

Demands

1. Fuse (10) for thermal release (1), comprising: - a bulb (12) containing a liquid, having a first end (12A) and a second end (12B), the bulb being configured to break when the liquid contained in the bulb reaches a predetermined temperature, - a first plate (14A) and a second plate (14B), characterized in that each of the first and second plates (14A, 14B) comprises: • a hooking end (16A, 16B), configured to allow the hooking of the plate (14A, 14B) to a hooking element (3, 5) of a thermal trigger (1); • a sliding portion (22A, 22B), connected to the hook end and having a planar shape extending along a sliding axis (X22A, X22B); • an exhaust portion (24A, 24B), connected to the sliding portion; and • a retaining end (30A, 30B), connected to the exhaust portion and comprising a receiving member (32A, 32B) and two retaining tabs (34A, 34B), and in that, in the assembled configuration of the fuse (10): - the bulb (12) extends between the retaining end (30A) of the first plate (14A) and the retaining end (30B) of the second plate (14B); - the receiving element (32A) of the retaining end (30A) of the first plate (14A) receives the first end (12A) of the bulb (12); - the receiving element (32B) of the retaining end (30B) of the second plate (14B) receives the second end (12B) of the bulb; - the sliding portion (22A) of the first plate (14A) is located between the two retaining tabs (34B) of the retaining end (30B) of the second plate (14B); the sliding portion (22B) of the second plate (14B) is located between the two retaining tabs (34A) of the retaining end (30A) of the first plate (14A); the second plate (14B) is movable in translation relative to the first plate (14A) along a translation axis (X22) parallel to the sliding axis (X22A) of the sliding portion of the first plate and parallel to the sliding axis (X22B) of the sliding portion of the second plate; and The bulb (12) blocks a translation of the second plate (14B) along the translation axis (X22) in a direction of approaching the retaining end (30B) of the second plate relative to the retaining end (30A) of the first plate.

2. Fuse (10) according to claim 1, further comprising a fixing piece (38), in which, in the assembled configuration of the fuse (10), the fixing piece (38) is fixed to the first plate (14A) and blocks a translation of the second plate (14B) along the translation axis (X22) in a direction away from the retaining end (30B) of the second plate relative to the retaining end (30A) of the first plate.

3. Fuse (10) according to claim 2, wherein the receiving member (32B) of the retaining end (30B) of the second plate (14B) is a receiving hole and wherein, in the assembled configuration of the fuse (10): - the second end (12B) of the bulb (12) extends through the receiving member (32B) of the retaining end of the second plate and passes through the retaining end of the second plate; and - the fixing piece (38) covers the receiving member (32B) of the retaining end of the second plate and surrounds the second end of the bulb.

4. Fuse (10) according to any one of claims 1 to 3, wherein a distance (34) separating the two retaining lugs (34A) from the first plate (14A), measured perpendicular to the sliding axis (X22A) of the first plate, is less than a width (£22) of the sliding portion (22B) of the second plate (14B), measured perpendicular to the sliding axis (X22B) of the second plate and greater than a width (£24) of the escape portion (24B) of the second plate, measured perpendicular to the sliding axis of the second plate, and in which a distance (£34) separating the two retaining tabs (34B) of the second plate (14B), measured perpendicular to the sliding axis (X22B) of the second plate, is less than a width (£22) of the sliding portion (22A) of the first plate (14A), measured perpendicular to the sliding axis (X22A) of the first plate and greater than a width (£24) of the escape portion (24A) of the first plate, measured perpendicular to the sliding axis of the first plate.

5. A fuse (10) according to claim 4, wherein each of the first and second plates (14A, 14B) further comprises a clearance portion (26A, 26B), located between the escape portion (24A, 24B) and the retaining end (30A, 30B) of the plate, comprising two clearance walls (28A, 28B) extending in a plane inclined (P28A, P28B) with respect to the sliding axis (X22A, X22B) of the plate, wherein a width (£26) of the clearance portion (26A) of the first plate (14A), measured perpendicular to the sliding axis (X22A) of the first plate at the level of the clearance walls (28A) of the first plate, is greater than the distance (£34) separating the two retaining tabs (34B) of the second plate (14B), and in which a width (£26) of the clearance portion (26B) of the second plate (14B),measured perpendicular to the sliding axis (X22B) of the second plate at the clearance walls (28A) of the second plate, is greater than the distance (£34) separating the two retaining tabs (34A) of the first plate (14A).

6. Fuse (10) according to any one of claims 1 to 5, wherein, for each of the first and second plates (14A, 14B), the retaining end (30A, 30B) has a planar shape and an angle (a) formed between the sliding portion (22A, 22B) and the retaining end is

7.

8.

9.

10. strictly greater than 90°, preferably between 100° and 110°. Fuse (10) according to any one of claims 1 to 6, wherein, for each of the first and second plates (14A, 14B), the latching end (16A, 16B) has a planar shape and forms an angle (|3) with the sliding portion (22A, 22B) between 158° and 160°, and wherein, preferably, in the assembled configuration of the fuse, the latching end (16A) of the first plate (14A) and the latching end (16B) of the second plate (14B) extend in the same latching plane (P 10). Fuse (10) according to any one of claims 1 to 7, wherein the first plate (14A) is identical to the second plate (14B). Thermal release (1) comprising: - a compressed gas cartridge (4), - a triggering element (5), configured to strike the compressed gas cartridge (4) when triggered, - a base (2) and - a fuse (10) according to any one of claims 1 to 8, the latching end (16A, 16B) of one of the plates (14A, 14B) between the first plate (14A) and the second plate (14B) being latched to the base (2) and the latching end of the other of the plates between the first plate and the second plate being latched to the tripping element (5), in which the fuse (10) is configured for: - prevent the triggering of the triggering element (5) when the bulb (12) is intact and - trigger the triggering element (5) when the bulb (12) breaks. Mounting jig (50) for assembling a fuse (10) according to claim 2, comprising: - retaining elements (54C, 56C, 58, 64), configured to hold the first plate (14A) and the second plate (14B) in position on the mounting template (50) while allowing translation of the first plate according the translation axis (X22) aimed at bringing the retaining end (30A) of the first plate closer to the retaining end (30B) of the second plate; - a bulb holder (60), configured to receive the bulb (12) and position the bulb between the retaining ends (30A, 30B) of the first and second plates (14A, 14B) and between the sliding portions (22A, 22B) of the first and second plates; and - a protrusion (64), configured to position the fixing piece (38) in contact with the first plate (14A).

11. A method for mounting a fuse (10) according to any one of claims 2 and 3, using the mounting jig (50) of claim 10, comprising at least the following steps: - assemble the first plate (14A) with the second plate (14B), by placing the two retaining tabs (34A) of the first plate at the level of the exhaust portion (24B) of the second plate and by placing the two retaining tabs (34B) of the second plate at the level of the exhaust portion (24A) of the first plate, then by moving the second plate relative to the first plate along the translation axis (X22) so as to move the retaining end (30B) of the second plate away from the retaining end (30A) of the first plate; - position the first plate (14A) and the second plate (14B) on the mounting template (50); - position the bulb (12) on the mounting template, preferably on the bulb holder (60), placing the first end (12A) of the bulb opposite the receiving element (32A) of the retaining end (30A) of the first plate and placing the second end (12B) of the bulb opposite the receiving element (32B) of the retaining end (30B) of the second plate; - move the first plate (14A) relative to the second plate (14B) along the translation axis (X22) so as to bring the retaining end (30A) closer to the first retaining end plate (30B) of the second plate until the bulb (12) blocks the movement of the first plate; position the fixing piece (38) on the mounting template; and fix the fixing piece (38) to the first plate (14A).

Images