FR2469637A1 - Cast-iron pipe coupling for low pressure application - has conical housings for pipe ends with V=section seals and stop lug - Google Patents

Abstract

The cast-iron pipe coupling accommodates straight tube at both ends. The coupling has conical housings at each end in which are 'V' shaped or chevron sealing rings. Between the two halves of the coupling is a spigot (8) which serves as a stop for the two tubes T1,T2). When the tube (T1) is inserted in the coupling, the chevron sealing ring is deformed to form a water-tight seal. The assembly has sufficient flexibility to allow each tube to be introduced at an angle not exceeding 7 degrees with the axis of the coupling, without affecting the integrity of the joint. These couplings are for pressures up to 5bar.

Description

 The present invention relates to a cast iron sleeve for the tight connection, without pressure or under low pressure not exceeding five bars, of tubular elements without embedding, for rainwater and wastewater evacuation pipes. that we use in the building.

 More particularly, but not exclusively, the invention relates to a sleeve usable for vertical pipes and oblique tubular elements to be connected to pipes of a Y-connector or "panty".

 But of course the sleeve, object of the invention, can also be used for horizontal pipes embedded or laid in fill and is also connectable to elbows and tubular branches.

Composite fittings are known that include a stainless steel clamp collar and an elastomeric cuff. The elastomer or rubber cuff which caps and connects the cylindrical and smooth ends of the tubular elements has a median internal shoulder for separating said ends and annular lips projecting internally, crushed by said ends to seal. The stainless steel collar can be tightened on the cuff using screws.

Technically, these known composite fittings are satisfactory, in particular because of their small radial size, but they have the disadvantage of having screws and of being devoid of means suitable for fixing to a wall or to another wall. pipe anchor. In addition, if they are used on a cast iron pipe, the stainless steel of the collar is a heterogeneous material compared to cast iron.

 Now, the advantages of cast iron are known, in particular for building pipes: cast iron is appreciated for its resistance to temperature variations, given its low coefficient of expansion which is seven to ten times lower than that of other materials, and for its resistance to noise, as well as for the absence of release of aggressive or dangerous vapors in the event of fire.

 Until now, we did not know how to make cast iron sleeves equivalent to the aforementioned composite fittings, that is to say having such a small external footprint to lend themselves to connections in places where a small space is available, for example. example between a downpipe and a toilet bowl, in a corner, on a branch fitting in panties, with short lengths of tubing. Indeed, a cast iron sleeve containing a pair of elastomeric sealing rings has a radial size substantially greater than that of a smooth stainless steel collar enveloping an elastic sealing cuff.

This problem of external radial bulk is solved thanks to the invention.

The invention therefore relates to a cast iron sleeve for sealingly connecting, under operating pressure indicated above, two tubular elements, this sleeve of the type comprising internally two annular housings for elastic sealing rings and a median internal shoulder to separate the ends of the tubular elements to be connected, being characterized in that it comprises at each of its two opposite ends, a frustoconical wall whose smallest diameter is situated at the end, and the maximum diameter forms a circular projection, said frustoconical wall serving, by its internal frustoconical shape, to house and support a sealing washer, and by its external frustoconical shape, serving to reduce the radial size of the sleeve at each of its ends.

This sleeve thus lends itself to connections, even on the two pipes of a panty at the same time.

According to another advantageous characteristic of the invention, the cast iron sleeve externally has a hollow annular housing between the two frustoconical walls for a collar for fixing to a wall wall,
Other characteristics and advantages will appear during the description which follows.

In the appended drawing given solely by way of example, - FIG. 1 is a sectional view of the sleeve of the invention, partially before the introduction of a straight tubular element and partially after the introduction of another straight tubular element, the sealed assembly being produced using a washer seal, Fig. 2 is a partial end view illustrating a sealing washer, - FIG. 3 is a sectional view of an assembly of two tubular elements and of a sleeve of the invention, with angular deviations of the tubular elements, - FIG. 4 illustrates comparatively in section two tight assemblies between a panty and two sleeves, with a half view for a sleeve of known type and a half view for the sleeve of the invention, - FIG. 5 is an elevational view illustrating the fixing of the sleeves of the invention uniting a panty with straight tubular elements, said sleeves being fixed to a vertical wall by collars, - FIG. 6 is a sectional view along line 6.6 of FIG. 5 illustrating the attachment of a sleeve to a wall using a collar.

According to the example of execution of FIGS. 1 and 2, the invention is applied to the connection of two straight tubular elements in cast iron T1 and T2 of the same diameter placed in extension of one another along a vertical axis XX, and more particularly to a sleeve
M connecting these two elements or pipes T1 and
T2, with the interposition of two seals or washers R of known type.

The sleeve M of the invention, made of cast iron, has, in accordance with the invention, a sinuous profile, of constant thickness or approximately, instead of being cylindrical and smooth on the outside.

The sleeve has two parts 1) its ends 2) a middle part.

 each of its ends, it has externally a frustoconical wall 1 converging towards said end where it ends in a collar 2 with slight convex rounding providing a cylindrical inlet 3 of diameter greater than the outside diameter of the pipes T1 or T2. The inlet 3 is of minimum diameter if we compare the diameters of the different parts of the sleeve M.

At its maximum outside diameter, the frustoconical wall 1 forms a circular projection 4 with respect to the middle part. This projection is also rounded.

 Internally, the frustoconical wall 1 has a profile parallel to the external profile and serves as a housing 5 for a sealing washer R described below.

 The intermediate part 6 of the sleeve is connected to the frustoconical walls 1 and therefore to the projections 4 and to the housings 5 by a pair of leaves 7 symmetrical with respect to a median internal circular cheek or shoulder 8 for separating the two pipes T1 and T2.

The cheek 8 has a cylindrical opening 9 with a diameter preferably between the internal and external diameters of the pipes T1 and T2.

Externally, the middle part 6 forms a cylindrical recess or groove for a fixing collar described below, this recess or this groove 6 being limited by the circular projections 4.

Internally, the middle part 6 has on either side of the internal circular cheek 8 and symmetrically with respect thereto two smooth and cylindrical cavities or interlocking bottoms for the ends of the pipes T1 and T2.

 the cavities 10 have an inside diameter substantially greater than the outside diameter of the pipes T1 and T2 to allow, as known, an angular movement of the pipes T1 and T2 assembled inside the sleeve.

Each sealing washer Rp of elastomer, of known type (FIGS. 1 and 2) has a triangular or V-shaped profile in the free state, the annular lips of which are braced by ribs 11 providing slots 12 regularly spaced apart.

Each washer R is housed inside a housing groove 5 of each frustoconical wall 1 where it finds support by marrying by its external surface the interior of the frustoconical wall of the rounded collar 2. The external surface of each washer R thus diverges from the axis XX of the sleeve M, going from the inlet 3 of the sleeve towards the internal circular cheek 8. On the contrary, in the free state, the internal surface 13 of the washer R converges towards the axis XX of the sleeve M from said inlet 3 towards said cheek 8, therefore forming a projection relative to the smooth cylindrical cavity 10, this projection having a minimum diameter substantially smaller than the outside diameter of each pipe T1 and T2 when it is not not yet inserted into the sleeve M (upper part of Fig. 1).

The lower part of Fig. 1 shows the sealed assembly or seal, of known type, produced between the sleeve M, the pipe Tl and the washer
R which is compressed radially in its housing 5 with flattening of the slots 12 between the frustoconical wall 1 and the pipe T1 which is introduced into the sleeve M by crossing the washer R and going inside the cavity 10 almost to the cheek 8 which he could run into.

If L designates the fitting depth of the pipe T inside the sleeve M, the fitting depth L allows greater tolerance in the execution of the cuts of the straight tubular elements Tî and T2 and allows a angular deviation x which is for example 70 per joint, and consequently a 2x deflection of 140 per sleeve M, without risk of dislocation.

As a result, the elbows, breeches and branches are easily adjustable (Fig. 3).

 Fig. 4 now illustrates the utility of the frustoconical walls 1 of the sleeve M of the invention.

Either to assemble a panty N having a main tube 14 of vertical axis XX and a branch tube 15 of oblique axis YY, and a confluence 16 between the two, with two tubular elements Tl and
T2 at the confluence point 16.

 It can be seen that the confluence 16 provides only a small volume between the pipes 14 and 15 for the engagement of the two sleeves M on said pipes in order to form the seal or the waterproof assembly described above.

However, the sleeves M being truncated at their ends along the frustoconical walls 1, they can be engaged and pushed as close as possible to the confluence 16 by sufficiently enveloping the tubes 14 and 15 so that the ends of the tubes 14 and 15 penetrate into the cylindrical cavities nesting 10.

Advantageously, the conicities of the frustoconical walls 1 are such that the generatrices of said walls located in the plane of intersection of the axes XX and
YY are parallel to the bisector B of the angle which the axes XX and YY cast between them, which makes it possible to push the sleeves M as far as possible towards the confluence 16 and to cover as much as possible the pipes 14 and 15 over a length L .

 If, in accordance with the usual known technique, the cast iron sleeves were not truncated but were cylindrical at their ends as illustrated in M1, in half-view in section and in half-view in phantom, the sleeves M1 would be stopped, during their insertion on the pipes 14 and 15, by the interference of their edges A.

They would only cover a length 1 of the pipes 14 and 15, less than L, and would only constitute an easily removable assembly.

 To constitute with the sleeves M1 a tight assembly as good as that which is produced with the sleeves M of the invention, it would be necessary to have pipes 14 and 15 substantially longer than the existing pipes, as shown in solid line, in half - seen in Fig. 4.

 Thanks to the reduction in its radial bulk at its ends, the sleeve M of the invention therefore makes it possible to use panties N with short pipes 14 and 15 in the same way as # very thin cylindrical sleeves made of stainless steel and not cast.

The frustoconical walls 1 of the invention therefore make it possible to use cast iron and the molding technique to produce the sleeves M of the invention and to benefit from the advantages which result therefrom.

Figs. 5 and 6 illustrate the usefulness of the outer groove 6 of the sleeve M. The groove 6 serves to house the collar 17 for fixing the sleeve M, therefore for fixing the assembly of the sleeve M with pants N and / or Tlo pipes T2, T3, on a wall P. The collar 17 is provided with clamping and fixing lugs on which is fixed a bolt 18 whose head is sealed in the wall P. The collar 17 is trapped by the projections 4 of the sleeve M which serve as stops and prevent it from sliding on the external surface 6 of the sleeve
M. In addition, the groove 6 advantageously makes it possible, in combination with the fillets 7 and with the collar 2, to easily mold the housing 5 of each seal R.

Claims (7)

 1.- Cast iron sleeve for the tight assembly of two tubular elements under an operating pressure not exceeding 5 bars, this sleeve, of the type comprising internally two annular housings for elastic sealing washers and comprising a median internal shoulder to separate the ends of the tubular elements to be connected, being characterized in that it comprises at each of its two opposite ends, a frustoconical wall (1) whose smallest diameter is located at the end and the maximum diameter forms a circular projection ( 4), said frustoconical wall serving, by virtue of its internal frustoconical shape, to house (5) and support for a sealing washer (R), and by its external frustoconical shape, serving to reduce the radial size of the sleeve at each of its ends.  2.- sleeve according to claim 1, characterized in that it has externally between the two frustoconical walls (1) a hollow annular housing 16) for a fixing collar (17) on a wall wall (P).  3.- Sleeve according to claim 1, characterized in that it has a sinuous profile with frustoconical walls (1), with projections (4), with a central groove (6) and with connection fillets (7). 4.- sleeve according to claim 2, characterized in that it comprises between the two frustoconical walls (1) of its two ends a circular groove (6) molded, of diameter substantially less than the maximum outside diameter of said frustoconical walls (1) in line with their circular protrusions (4), said groove (6) being capable of serving as a housing for a fixing collar (17), and the protrusions (4) of maximum diameter being capable of serving as axial stops for this necklace. 5.- sleeve according to claim 1, characterized in that the end of small diameter of each frustoconical wall (1) ends in a collar (2) with convex rounding which is internally molded by the external surface of a sealing washer (R).  6.- sleeve according to claim 1, characterized in that each circular projection (4) is rounded.  7.- sleeve according to claim 1, characterized in that the frustoconical walls (1) have a taper such that when the sleeve is assembled with a straight tube of a panty (N) and that another sleeve of the invention is assembled with a branch pipe (15) of said panty (N), in the vicinity of the confluence (16) of the two pipes (14 - 15), the frustoconical walls (1) of the two sleeves have a generatrix located in the plane intersection of the axes (XX and YY) of said tubes which is parallel to the bisector (B) of the angle that said axes make between themselves, said bisector (B) passing through said confluence (16).