AUTOLOCKING FITTING FOR PIPES IN PARTICULAIR HAVING A STRUCTURE STRENGHTHENED BY WIRE LIKE ELEMENTS

Abstract: The autolocking fitting for pipes comprises a first (2) and second (3) tubular bodies, a bush element (5) effective to be housed inside the second tubular body (3), a pair of shells (6) effective to be housed, jointly or separately, inside the bush element (5) and defining thereinside a tapering portion (32) forcedly engaged by the end portion of a pipe (34), and an expander element (4) force- inserted within the pipe of the first tubular body.

Description: Autolocking fitting for pipes in particular having a stM### J ( I strenghthened by wire like elements. Ehe present invention relates to an autolocking fitting for pipes, in particular having a structure strengthened by wire-like elements. Several fittings are known effective to be applied to the end portions of pipes, which fittings are affected by a number of drawbacks, in that they, lacking of sufficient autolocking characteristics, are not able of assuring a sufficient tightness to the tensile stresses affecting the coupled pipe elements, in that they, after installation1 may be hardly recovered(that is may not be reused),and in that they are of a comparatively complex structure, high cost and scarcely usable in a broad range of applications. In particular the known fittings fail mainly as the pipes to be coupled have a structure strengthened by wire-like elements. In that case the cut through zone of such a pipe is hardly a perfect one, because the wire-like elements break away thereby projecting from the cut region. Ihat fact causes two drawbacks to occur: - upon mounting, it is difficult, because of the projecting wire-like elements,to properly locating the bush or collar members forming the #oints.After having carried out said locating operation, the cut region will be yet more unprecise,because of the greater breaking of the textile element. - as the Joint is tight clamped, said wire or thread like elements, if they are not properly united or trim- ed,may interfere with the tightness surfaces, thereby an objectionable leakage will occur. Accordingly, the task of the present invention is to provide such an autolocking pipe fitting which is effective to facilitate the assembling and dis assembling operations even in the case therein the pipes have a structure strengthened by wire or thread like elements. Within that task, it is a main object of the present invention to provide such a fitting having a comparatively reduced cost and effective to be completely recovered and reused, and not to obstruct the passage of the fluid at the fitting. According to one aspect of the present invention the above task and object, as well as yet other obJects iiich will become more apparent hereinafter, are achieved by an autolocking fitting for pipes according to claim 1. The invention will be thereinafter disclosed and illustrated,by#ay of exa#ple,with reference to the figures of the accompanying drawing, where: figure 1 is a partially sectioned exploded view of the fitting or pipe joint according to the invention; figure 2 is a partially sectioned view of that joint or fitting with one end thereof coupled to a pipe;and figure 3 is a cross-sectional view taken through the lino Il-Il of fig.2. With reference to the above mentioned figures, the fitting or joint according to the invention, as overally indicated at l,comprises:a fi6st tubular body 2 and a second tubular body 3,as well as an expander 4,a bush 5 and a pair of semicircular shells 6 whereof one only has been shown in figure 1. The first tubular body 2 comprises a first and second cylindrical portions 7 and 8,provided Witl outside threads 9 and 10 respectively bridging a driving element 11.The first cylindrical portion 7 comprises a duct 12 being coupled to a duct 13 of the second cylindrical portion 8 at a shoulder 14. The second tubular body 3 comprises a cylindrical portion 21 with a subsequent driving element 22 the inside thereof is threaded at 23. Said thread ends at an annular chamber 24, arranged between said thread and a duct 25 and defining with the latter a shoulder 27. The expander 4 consists of a cylindrical portion 15,having such a diameter as to abut against the shoulder 14 and included between two recessed portions 16 and 17 respectively a top and lower one, the top one whereof is effective to house a 0-ring member 18.A tapered portion 19 is provided adjoining said recessed portion 17,also traversed by a cylindrical duct 20. The bush 5 has a cylindrical shape and, at one end thereof, is provided with a collar or flange 26 the shape and size whereof are substantially complementary with respect to the annular chamber 24 and related shoulder 27. The half-shells 6 are provided at the top portion of an edge 28 having such a diameter as to abut on the top surface 29 of the collar 26,the maximum diameter of the body, as measured at the point 30 at a level of about 3/4 of the height of said bocLy,interfering with the inner duct 31 of the bush 5. In its inside the half-shell 6 has a tapered portion 32 complementary to the tapered portion 19 of the expander 4. Assembling procedure the end portion 33 of a pipe 34 of the strengthened structure type is inserted into the second tubular body 3:that operation, because of the comparatively great clearance between the duct 25 and pipe 34,is an easy one. Then the bush 5 is threaded on the end portion of the pipe 33 as far as the shoulder 26 is located at the annular chamber 24 in such a way as to abut against the shoulder 27. The latter operation is also an easy one, owing to the difference yet existing between the inner diameter of the bush and the pipe outer diameter. The half-shell pairs6 are superimposed on the end portion of the pipe in such a way that the end portion 33 thereof is located at the inner portion of the edging 28. Then the half-shells are simultaneously Jointed to the pipe inside the bush 5, in such a way that the edge 28 coincides with the inner portion of the collar 26 by abutting thereon and arranging itself in the annular chamber 24. Also that operation is an easy one, owing to the clearance yet existing between the pipe 34,halr- shells 6 and bush 5. Then the expander 4 is progressively forceinserted into Ite pipe 34, thereby spreading the end portion 33 thereof as rar as to cancel the clearance between the elements 3,5,6,34. The first tubular body 2 is then screwed on the second tubular body 3 in such a way as to engage the thread 10 with the thread 23. The expander 4,as it abuts against the shoulder 14, will be forced inside the pipe 34. Then the tapered portion 19 will provide the set pressure on the inside walls of the pipe in such a way as to assure the required mechanical and hydraulic tightness and by forcing the elements 34, 6,5 and 3. After the clamping step, the top thread or portion 33 of the pipe 34 will resiliently engage the lower recessed portion 17 of the expander 4,thereby contributing in a great degree to the counterbiassing of the possible stresses susceptible to disengage the pipe from the fitting. The cylindrical portion 15 is coupled with clearance to the walls of the duct 13 which act as a guide for said expander, the 0-ring 18 providing the hydraulic tightness and preventing leakage through said fsurfaces from occuring. Then the second pipe length, not shown, is coupled to the Joint 1 in a conventional way through the thread 9.

Claims: OLA IMS 1- An autolocking fitting for pipes, characterized in that it comprises a first (2) and a second (3) tubular bodlesa bush element (5) effective to be housed inside the second tubular body (3),a pair of shells (6),in turn effective to be housed, either coupled or separated,inside said element (5) and defining thereinside a tapered portion (32) force engaged by the end portion of a pipe (34),and an expander element (4) forced inside said pipe by the first tubular body (2). 2- An autolocking fitting according to claim 1, characterized in that the first tubular body (2) is provided on its outside with a first (9) and second (10) outer threads and a driving element (11) interposed between said two threads and, on its inside,with a first (12) and second (13) ducts, separated by a shoulder (14),said first (12) and second (13) duct being respectively provided at said threads (9) and (10). 3- An autolocking fitting according to claim 1, characterized in that the second tubular body (3) consists of a cylindrical portion (2l),a driving element (22), a thread (23),an annular chamber (24),a duct (25) and a shoulder (27),the cylindrical portion (21) and driving element (22) being successively arranged as respectively associated with the duct (25) and thread (23) with the interposition of the annular chamber (24) and related shoulder (29). 4- A device according to claim 1, characterized in that the expander (4) is provided with a cylindrical portion (15),a first (16) and second (17) recessed portions, respectively- a top and lower one, to a tapered portion (l9),said first (16)and second (17) recessed portions being arranged at the ends of the cylindrical portion (15),the latter being coupled to the tapered portion (19),said cylindrical portion (15) and said tapered portion (19) being traversed by a duct (20). 5- A device according to claim 1, characterized in that the bush element (5) is provided, at one end thereof, with a collar (26). 6- A device according to claim 1,characterized in that it comprises at least a pair of hal±-ahells (6), provided, in the inside thereof, with a tapered portion (32) and including, at one end, an edge (28) having a substantially conical outside profile. 7- A device according to the preceding claim, characterized in that said bush element consists of two separated elements. 8- A device according to claim 6,characterized in that said tapered portion (32) is complementary with respect to said tapered portion (19).

Inventors: TALE, PAOLO, Talé, Paolo
Applicants: TALE, PAOLO
Application year: 1985
Main classification: F16L33
IPC codes: F16L33