Fluid conduit coupling device

Abstract: The device includes a head (1) provided with a coupling thread for a sleeve (4) which incorporates a straight-profiled dentation (6), whilst between the sleeve and the head there is a complementary ring (7) provided with another dentation (8). The dentations are oriented to permit the sleeve to turn in a tightening direction and to prevent it from turning in the opposite direction at the end of the coupling phase by means of angular fixing means consisting of a plurality of lugs (9) arranged on the perifery of the complementary ring. The dentation at the front of the sleeve and the dentation of the complementary ring cover these elements totally or in part.

Description: The present invention refers to a fluid conduit coupling device. The specific purpose of the invention is to design the device such that the conduits are not accidentally dismounted, once coupled, and if they are voluntarily uncoupled, that evidence of such removal remains. The coupling between fluid conduits is generally based in the prior art on a threaded head which connects with a matching threaded sleeve. In practice, a looseness is very frequently produced between these two coupled parts as a consequence of vibrations to which the installation is submitted or due to water hammers, etc. On the other hand, the coupling described in the prior art generally does not allow knowing whether the coupling has been unduly tampered. To solve these problems US-A-3608933 discloses a coupling device avoiding the accidental slacking or unscrewing and indicates whether the coupling, after having been assembled, has been tampered. To this end, the known device uses two complementary and indented rings, one of them fixed to the head and the other fixed to the sleeve, facing each other on their indented side, the teeth allowing to screw in one direction, the tightening sense, but not allowing to unscrew in the opposite direction. Therefore, the above two rings, with their teeth facing each other, not only avoid the unscrewing or slacking of the coupling as described above but, moreover, make it possible to detect any attempt of tampering, given that either the teeth or the mechanism fastening the indented rings to the head and/or the sleeve would be broken. Although this system resolves the problem stated earlier, this solution implies high economic costs, since two indented rings are necessary and, moreover, these rings must be fastened to the head and sleeve which form the coupling. The object of the invention is to provide for a device which is specially suitable for use in those cases in which uncontrolled tamperings of the coupling ought to be avoided, or in those cases in which a possibility of uncoupling, due to vibrations, water-hammers, etc., is visualised, wherein the coupling device has the advantage of structural simplicity, which permits its manufacture at a low cost, without losing its efficacy. This object is obtained by the features of the patent claim. The coupling device of the invention has been designed to overcome these problems satisfactorily and, therefore, it is characterized not only by the incorporation on the head and the sleeve of an anti-unscrewing mechanism, but also by a structural simplicity. More specifically, this mechanism has been provided with complementary straight teeth, so that at the maximum threaded position of the sleeve the said teeth permit such operation to take place until the complete maximum tightened position is reached, by means of the "jumping" of some teeth onto others through their inclined planes, whilst it is absolutely impossible for the sleeve to turn in the opposite direction, that is to say, in the unscrewing direction, since the teeth, in this direction, face one another through their straight perpendicular planes. Further, whereas the dentation corresponding to the sleeve is formed on the opening of the sleeve, the dentation corresponding to the head is not formed on the head but on the complementary ring provided in turn with lugs through which the head is blocked in an angular position by means of the coupling of the said lugs in corresponding indentations of the head. This prevents, as previously mentioned, the accidental unscrewing of the coupling. However, it permits the voluntary unscrewing by breaking the said lugs, in which case the complementary ring could turn freely with respect to the head during the unscrewing operation. As it is obvious, the coupling device of the invention is likewise applicable to fluid conduits in which the sleeve is coupled to the head by means of a bayonet system. DESCRIPTION OF THE DRAWINGS A complete description will now be made of the said coupling device for fluid conduits, with reference to the accompanying drawings, in which, merely by way of example and not limiting, a preferred mode of embodiment is represented, the details of which may be modified without fundamentally altering the main characteristics thereof. In the said drawings. Figure 1.- Illustrates a side elevational view of a head pertaining to a fluid conduit provided with the coupling device of the present invention. Figure 2.- Illustrates an axial view of the same head. Figure 3.- Illustrates an axial view of the complementary ring. Figure 4.- Illustrates a side elevational view of the same ring. Figure 5.- Illustrates a side elevational view of the sleeve complementary to the former parts. Figure 6.- Illustrates an axial view of the same sleeve. Figure 7.- Illustrates a side elevational view of the head, the complementary ring and the sleeve, suitably faced, in accordance with the subsequent assembly position thereof. Figure 8.- Illustrates the unit of figure 7 once mounted or definitely coupled. Figure 9.- Illustrates a side elevation, quarter-sectional view of a sleeve similar to that represented in figures 5 and 6, but the dentation of which is slightly set back with respect to its edge so that it will not be noticeable from the outside. Figure 10.- Illustrates an axial view of the sleeve represented in figure 9. Figure 11.- Illustrates a side elevation, quarter-sectional view of a complementary ring provided with four fixing lugs to the head instead of two as in the case of figure 4. Figure 12.- Finally illustrates an axial view of the head cooperating with the ring of figure 11. PREFERRED EMBODIMENT OF THE INVENTION Referring to the drawings, it can be seen that the coupling device of the invention is applicable to fluid conduits in which a determined conduit or pipe is provided with a head 1, ending in a neck 2, provided with a male thread 3 on which is mounted a sleeve 4 provided, in turn, with a complementary female thread, the said head 1 being provided with an external petrimetral staggering 5 acting as a penetration stop for the said sleeve 4. Departing from this structure, which should not be regarded in an exclusive sense since the coupling between the sleeve 4 and the head 1 could also be of the bayonet type, the invention is characterised in that the said sleeve 4 incorporates at its front edge a dentation 6, having a straight profile, whilst the head 1 is aided by a complementary ring 7 provided with a dentation 8 which, in turn, is complementary of the dentation 6 of the sleeve 4. Thus, the orientation of the teeth of these two dentations 6 and 8 is such that it permits the relative turn of the sleeve 4 with respect to the head 1 in a threading or coupling direction between such elements, whereas it prevents the relative movement thereof in the opposite direction, that is to say, the said teeth act as anti-unscrewing means, wherefore and as it can be seen, the complementary ring 7 should be provided with anti-turning fixing means to the head 1. The said angular fixing means consists of lugs 9 which protrude from the complementary ring 7 in a parallel arrangement to its axis and which fit into indentations 10 of the head 1. There could be two of such lugs 9 and such notches 10 and they are capable of being positioned in diametral opposition, as in the practical mode of embodiment shown in figures 1 to 8, or there could be four and they may also be equiangularly arranged, as in the case of figures 11 and 12. Although in the practical mode of embodiment of the drawings, and as can be seen specifically in figures 3 and 6, the dentation 6 of the sleeve 4 covers the front edge thereof completely, as in the case of the dentation 8 of the complementary ring 7, these dentations may be partial, without departing from the scope of the invention. Also, optionally, the dentation 6 of the sleeve 4 may be open laterally towards the also lateral wall of the said sleeve, as in the case of figures 1 to 8, or the dentation 6 may be set back with respect to the outer face 11 of the sleeve 4, as can be seen in figure 9 and specially in the enlarged detail thereof, establishing on the outside of the teeth 6 a smooth continuous sector 12 which conceals the said teeth once the sleeve has been assembled to the head and when viewing the assembly normally. It should be emphasised that, although the sleeve 4 has been represented in the drawings with a smooth outer surface, this is preferably fluted, knurled or provided with any type of roughness which facilitates the tightening operation thereof. As can also be seen, the coupling device is not only applicable to the direct joining between two conduits, but also to the joining of conduits with the help of straight connector elbows, "T's", or any other conventional accessory of this type. In any case and as can be seen in an assembly as that of figures 7 and 8, the complementary dentations 6 and 8 permit the device to be manipulated in the tightening direction for coupling, since the complementary ring 7 is maintained securely joined to the head 1 and is consequently blocked because its lugs 9, whether two or four, are housed in the corresponding indentations 10 of the head 1. This prevents an accidental uncoupling, due to vibrations, water hammer or the like, from taking place, whilst it permits a voluntary uncoupling, specifically by breaking the lugs 9, wherefore the complementary ring 7 is freed from the head 1, but evidence thereof remains due to the non-existence of the said lugs 9. Therefore, in order to avoid tamperings of which there is no evidence, when replacing the broken complementary ring for a new one, in the initial marketing of the device all the coupling parts will have a determined colour, whereas the spare complementary rings will have another colour, so that their replacement within the installation will immediately be noticed.

Claims: Fluid conduit coupling device including a head (1) provided with a coupling thread (3) for a sleeve (4) by means of which the corresponding conduit is tightly secured to the said head (1) or in which the sleeve (4) is coupled to the head (1) by means of a bayonet system, in which coupling the said sleeve (4) incorporates at its front edge a straight-profiled dentation (6), whilst between the said sleeve (4) and a stop portion on the head (1) there is provided a complementary ring (7) provided, in turn, with another dentation (8), complementary of that incorporated to the sleeve (4), and the said dentations (6, 8) are oriented so as to permit the sleeve (4) to turn in a tightening direction, and to prevent it from turning in the opposite direction at the end of the coupling phase, the said complementary ring (7) is provided with angular fixing means (9) fixing it to the head (1), said means consisting of a plurality of lugs (9) arranged on the complementary ring (7), forming a monopiece with the said ring (7) and designed to fit snugly inside respective indentations (10) established in the head (1), the said lugs (9) being frangible in order to permit the voluntary angular uncoupling between the ring (7) and the head (1), for a necessary dismounting in the installation. Fluid conduit coupling device according to the preceding claim, characterised in that both the dentation (6) at the front of the sleeve (4) and the dentation (8) of the complementary ring (7) cover these elements totally or in part. Fluid conduit coupling device according to the preceding claims, characterised in that the dentation (6) of the sleeve (4) covers the free edge thereof completely or it is set back with respect to its outer side surface, forming at its opening an outer continuous perimetral sector (12), which conceals the dentation (6).

Inventors: URIARTE ODRIOZOLA JOSE IGNACIO, URIARTE ODRIOZOLA, JOSE IGNACIO, Uriarte Odriozola, José Ignacio
Applicants: TERRAIN SDP S A, TERRAIN SDP, S.A.
Application year: 1989
Main classification: F16L19
IPC codes: F16B39, F16B41, F16L19