FR2571826A1 - Linking devices using a meltable alloy with high mechanical strength - Google Patents

Abstract

The invention consists in linking two parts using a device of very high mechanical strength, but whose meltable linking agent allows the two parts to be disconnected upon achieving a thermal or otherwise predetermined condition. A device according to the invention comprises, for example, two identical parts mounted head-to-foot according to Figure 1, and denoted 1 and 2, which have the peculiarity of having, at their point of tensile anchoring 3 a very slight angle 4 whose sides are either in the plane of the parts 1 and 2, or in the plane perpendicular to the latter. If a closely fitting sheath 5 is slid over the anchoring point 3, the tearing-apart movement applied by virtue of eyelets 6 on the parts 1 and 2 can separate them only if the sheath 5 loosens. Thus, the latter, due to the small angles 4 of the anchoring point 3, only has to have a low mechanical strength to prevent this separation.

Description

 The present invention relates to a device used to block the movement of a mechanism in a position and to release it from certain parameters such as for example a positive or negative temperature if the Celsius scale is used.

 There are already many devices in accordance with the aims of the invention.

Some use a fusible material which blocks a motion amplifying device, which, released by the melting of the fuse, releases the mechanism to be controlled. In the case of use as thermal fuses, others use micro-conductors with thermoelectric effect driving a relay controlling the mechanism to be released; others are simply the well-known thermoelectric relays, adjustable or not, using the deformation of a metal strip, for example composed of one or more materials with different expansion.

 The device according to the invention is characterized by its very great simplicity of construction, implementation and, possibly, rearming.

 A device according to the invention comprises, for example, two symmetrical substantially parallelepipedic parts, mounted head to tail, according to FIG. 1 and denoted (1) and (2), which have the particularity of having at their point of attachment in traction (3) a very slight angle (4) whose sides are either in the plane of the parts (1) and (2), or in the plane perpendicular to the latter (trace of the stamping tool), or in combination of the two.

If we slide a sheath (5) well adjusted, covering the anchor point (3), the tear-off movement applied thanks to the eyelets (6) on the parts (1) and (2) cannot make them unhook only if the sheath (5) drops. However, the latter, because of the small angles (4) of the attachment (3) only needs a little mechanical resistance to prevent this unhooking.

In the context of the invention, the sheath (5) consists of a fusible alloy or at least two parts made integral by a layer of heat-fusible material, adapted to the desired temperature for the action. At this temperature, its mechanical characteristics disappear and the parts (1) and (2), stressed in traction, can detach, which frees the device to be controlled;
Of course, and still according to the invention, the parts (1) and (2) can be, for example, round or square bars, always provided with the attachment point (3).

 Still in accordance with the invention, the fusible sleeve (5) may not be slid over all of the parts (1) and (2), but screwed above or below.

Any arrangement or means of manufacturing the fusible sheath (5) on the parts (1) and (2) is part of the invention.

 A device according to the invention is very easy to install, unlike the thermo-mechanical devices already known, based on the use of a thermal fuse and has the advantage of being very easily reusable by simple replacement of the fusible sheath.

 Still according to the invention, the fusible sheath (5) can have all the possible external shapes, including fins to increase the speed of the thermal action.

 Still in accordance with the invention, the sheath (5) can be replaced by simple welding or gluing of the parts (1) and (2) produced with a suitable fusible material (5), FIG. 2. This device retains the anchor point (3), the angle (4) and the eyelets (6). However, in this case, the ease of rearming provided by the sleeve (5) is no longer ensured.

Naturally, the invention is not limited to the embodiments of Figures 1 and 2. For example
Figure 3 shows an anchor (1) executed by folding the two identical parts (2) and (2). This anchoring (1) is blocked by deposit of fusible alloy (3) and (3).

 Figure 4 shows an anchor (1) and (1) executed by blind stamping or not of the two identical parts (2) and (2), these two parts also being secured by, for example, a deposit of fusible alloy (3 ).

 Figure 5 shows another embodiment of the invention also comprising two stampings (1) and (1) as-in Figure4, but spherical, on the identical parts (2) and (2) and each trapping a ball. The parts (2) and (2) are held by the fusible alloy deposits (3) and (3) for example.

 Naturally, the use of the devices according to the invention is not limited to the thermal domain alone. The invention is also intended, for example, for hygrometric, atmospheric domains or any other domain subject to variations in parameters making it possible to produce the sheath (5) in FIG. 1 or any other device having the same function, in accordance with invention with a material reacting to the variation of the parameter to be taken into account.

 Naturally, any device according to the invention can operate both under pressure and under traction.

Claims (4)

 1) Safety device by stall blocked by an external fusible material shown in Figure 1 or an apparent weld according to for example Figures 2, 3, 4 and 5  2) Device according to claim 1 characterized in that the device can be made from two identical parts (1) and (2), fig 1 and 2 or (2) and (2) Figures 3, 4 and 5.  3j Device according to Claims 1 and 2, characterized in that the fusible sheath (5) can be either slid, either screwed or glued to trap the attachment point (3), Figure 1.  43 Device according to claims 1 and 2 characterized in that the attachment point (3) figures 1, 2, 3 and 4 has at least a very small angle (4), allowing the parts (l) and - (2), figures 1 and 2 or (2) and (2), FIGS. 3 and 4, to bend over when subjected to a traction on the sheath (5) or on the fusible link weld (s) with very little force applied .  5) Device according to claims 1 and 3 characterized in that the sheath (5) may have any external shape file and may be reinforced by a sleeve or a hoop.  6) Device according to claim 2 characterized in that the anchoring is carried out by at least one ball, according to the example in FIG. 5.