DEVICE ON A CONDUIT END AND ARRANGEMENT FOR JOINING CONDUITS

Abstract: A device on a conduit end for joining the conduit (1) to a coupling (4) or some other receiver of the end of the conduit, which is made of aluminium or an aluminium alloy. Two external annular beads (2, 2') are pressed out from the conduit wall on the conduit end and accommodate between themselves an O ring (3). In an arranged for joining, the receiver (4) has a conical inlet and means, which together with the rear annular bead (2) form engaging means for a tightening means.

Description: DEVICE ON A CONDUIT END AND ARRANGEMENT FOR JOINING CONDUITS The present invention relates to a device on a conduit end and an arrangement for joining conduits. Many methods are known for joining components for fluid pipes, e.g. conduits. One method aims at welding or soldering collars in/to the conduit ends, between which collars a flat packing is clamped by means of bolts which are screwed through flanges attached to the conduits. The bolts must be forcefully tightened so as to achieve a satisfactory seal. In another method, coni- cal sockets instead of collars are welded/soldered to the conduit ends which are joined by means of corresponding conical couplings, the conduits and the coupling being also in this case interconnected by means of bolts that are screwed through flanges. Sealing is effected by means of 0 rings arranged in grooves in the sockets. Obviously the methods require a relative large number of components and relatively great efforts and are cost-intensive also for the reason that a relatively expensive material, such as copper, brass or steel, must be used. A less expensive piping is obtained with aluminium, use being made of conduits with protruding ends and coupling components which are die-cast and formed with threads but which must be machined owing to the fact that small tolerances are required for obtaining a satisfactory seal with the flat packing when the fluid has operating pressure. The machining operation involves a risk that the die-cast material obtains pores, thereby causing leakage in the coupling component. An object of the invention is to provide a device which permits joining of conduits in an inexpensive and efficient manner and which does not result in a reduction of the inner cross-section of the conduits which are joined together. The object is achieved by a device and an arrangement according to the claims. The invention will now be described in more detail with reference to the accompanying drawings, in which Fig. 1 is longitudinal section of a longitudinal part of a conduit and a longitudinal section of a T-shaped pipe coupling, Figs 2a and 2b are a side view and a top plan view of a joining rider, and Fig. 3 is a view illustrating the principle of the invention applied to two conduits, which are shown in longitudinal section, while the joining rider is shown in a perspective view. According to the invention, the conduit 1 made of aluminium or an aluminium alloy is provided with two external annular beads 2, 2' at its joining end, said beads being formed of the actual conduit wall in a bulging lathe. The space between the beads is adapted to receive an 0 ring seal 3, which is pulled over the outer bead 2'. The coupling 4 is, for instance, die-cast of aluminium and its inlets/outlets 4A-4C are somewhat coni- cal. Since the 0 ring is locked by the beads 2, 2', the coupling need not be machined to obtain a close tolerance for receiving the conduit, and a radial seal is obtained between the conduit and the coupling without necessitating a great tightening force on the 0 ring. For easily releasable tightening after joining, use can be made of a rider 5, the legs 7 of which engage behind the inner bead 2 and in a groove β formed in the outside of the coupling. The front bead 2' may consist of a widened end portion of the conduit 1. It will be appreciated that no coupling 4 is required for connecting two conduits. According to Fig. 3, the second conduit 1' can, by pressure turning, be provided with a widened end portion 8 for receiving the end of the conduit 1, which is provided with the beads 2, 2' and the 0 ring 3, and with, for instance, a posteriorly situated bead 8 ' for forming the groove 6 for a rider leg 7 as described above. Furthermore, any suitable means other than a rider as above can be used for tightening, e.g. a self-threading screw, which is screwed into a bore formed in e.g. the wall of the coupling in parallel with the connecting direction, the underside of the screw head or a washer being supported against the rear bead 2.

Claims: CLAIMS 1. A device on a conduit end for joining the conduit (1) to a coupling (4) or some other receiver (1') of the conduit end, said conduit being made of aluminium or an aluminium alloy, c h a r a c t e r i s e d by two external annular beads (2, 2') which are pressed out from the conduit wall on the conduit end and which between them- selves accommodate an 0 ring (3) , the rear annular bead (2) being adapted to constitute a support for a means (5) for tightening the conduit and a receiver of the conduit end, e.g. a coupling (4) or the end (8) of another conduit (1' ) . 2. An arrangement for tight joining of a conduit made of aluminium or an aluminium alloy to a receiver for the conduit end, e.g. a coupling (4) or the end (8) of another conduit (S') r said arrangement comprising a seal (3) and a tightening means (5), c h a r a c t e r - i s e d in that on the conduit end there are arranged two external annular beads (2, 2'), which are pressed out from the conduit wall and which between themselves accommodate an 0 ring (3), and that the rear annular bead (2) and an annular flange or groove (6) on the receiver is adapted to serve as engaging means for the tightening means . 3. An arrangement as claimed in claim 2, c h a r a c t e r i s e d in that the tightening means is in the form of a rider (5) . 4. An arrangement as claimed in claim 2, c h a r a c t e r i s e d in that the tightening means comprises a screw and a bore for the screw in the receiver. 5. A method for providing the annular beads on the conduit end as claimed in any one of claims 1-4, c h a r a c t e r i s e d in that use is made of a bulging lathe .

Inventors: LARSSON BENGT I, SVENSSON VIVEKA, LARSSON, BENGT, I., SVENSSON, VIVEKA
Applicants: DRESSER WAYNE AKTIEBOLAG, LARSSON BENGT I, SVENSSON VIVEKA, LARSSON, BENGT, I., SVENSSON, VIVEKA
Application year: 1997
Main classification: F16L21
IPC codes: F16L37