GB2151323A - Improvements in or relating to hose couplings - Google Patents

Abstract

Hose couplings are described which provide a leak-free coupling between two torsionally rigid hoses such that torsional stresses are accommodated by relative rotation of the hoses and are not transmitted to the coupling locking means. Accordingly a coupling for connecting two hoses comprises a first tubular member 10 having a female portion 14 and means 11 for joining the member to a hose, a second tubular member 20 having a male portion 21 and means 27 for joining the member to a hose, the male portion being co- operable with the female portion of the first member. O-Ring seals 17 are disposed between the first member and the second member, the two members being held united by locking means 30 such that relative rotation between the first and second members is allowed. The locking means may be engageable by a bayonet-type coupling or by screw-threaded engagement. <IMAGE>

Description

SPECIFICATION Improvements in or relating to hose couplings The present invention relates to hose couplings particularly those types of coupling used with torsionally rigid hoses on breathing apparatus.

Conventional hose couplings used on breathing apparatus were usually employed with a torsionally rigid wire reinforced hose one side of the coupling and a flexible hose on the other side. Torsional stresses and strains were, therefore, accommodated by twisting of the flexible hose.

Problems have arisen in recent years whereby torsionally rigid hoses have been employed on both sides of the coupling. Instances have occurred of conventional couplings becoming disconnected in operation.

Evidently this can have disastrous consequences if occurring to the pilot in a high flying aircraft for example.

An object of the present invention is to provide a leak-free coupling between two torsionally rigid hoses such that torsional stresses are accommodated by relative rotation of the hoses on either side of the coupling and are not transmitted to the coupling locking means thereby preventing accidental disconnection.

According to the present invention a coupling for connecting two hoses comprises a first tubular member having a female portion and means for joining the member to a hose, a second tubular member having a male portion and means for joining the member to a hose and the male portion being co-operable with the female portion of the first member, sealing means disposed between the female portion of the first member and the male portion of the second member, the two members being held united by locking means such that leak-free relative rotation between the first member and the second member is allowed.

Preferably the sealing means comprises rub ber 'O' ring seals retained in grooves machined either in the female portion of the first member or in grooves machined on the male portion of the second member.

The locking means may comprise a spring loaded collet around one tubular member engagable by a bayonet locking action with pegs located on or around the other tubular member. Alternatively, the locking means may comprise a female screw threaded collet around one tubular member the collet thread being co-operable with a male screw thread on or around the other tubular member.

In order that the invention may be more fully understood embodiments will now be described by way of example only with reference to the accompanying drawings of which: Figure 1 shows the part-sectioned components of a hose coupling having bayonet locking means, and Figure 2 shows a similar hose coupling to that shown in Fig. 1 but having alternative screw thread locking means.

Refering now to Fig. 1. The hose coupling comprises a first tubular member indicated at 10 a second tubular member indicated at 20 and a locking collet ring indicated at 30. The member 10 has a portion 11 to which a length of hose 12 (not shown) is affixable and a portion 13 which has a female bore 14 having a tapered entry 15 and two grooves 16 for receiving '0' ring seals 17. On the portion 13 are two short round pegs 18. The member 20 has a smooth male portion 21 with a tapered end 22, a flange 23, a short helical spring 24, a groove 25 for accepting a circlip 26 and a portion 27 to which a length of hose 28 (not shown) is affixable. The locking collet ring 30 is of tubular section the boe 31 of which is of sufficient diameter to pass over the flange 23 of the member 20.

Diametrally disposed at one end of the ring 30 are two slots 32 having circumferential and axial extensions 33 and 34 engageable with the round pegs 18 of the member 10.

The slots and extensions 32, 33 and 34 providing a push and twist locking action with the pegs 18. At the opposite end of the collet ring 30 is an inwardly turned flange 35. The outside of the ring 30 has a knurled finish 36 to provide a gripping surface.

In operation the male portion 21 of the member 20 is inserted into the female bore 14 the '0' ring seals 17 effecting a gas tight connection. The collet member 30 slides over the hose connection portion 27 of member 20 until the flange 35 abuts flange 23 trapping the helical spring 24 in-between. The slots 32 are engaged with the pegs 18 and by twisting the member 30 in a circumferential direction and then releasing the pegs are locked into the slot extensions 34. The circlip 26 is snapped into the groove 25 behind the flange 35 of the collet 30. The hose coupling is now made with the member 20 able to rotate freely in the member 10. The helical spring 24 exerts a force against the flange 35 preventing accidental disengagement due to vibration or compression of the hoses across the joint.In practice the collet member 30 and the male member 20 are held together as a single unit by the circlip 26.

Referring now to Fig. 2 where the same numbers denote the same features as in Fig.

1. Again in practice the male member 20 and collet member 30 are effectively a single unit by virtue o the collet 30 being held in place by the circlip 26. The alternative embodiment has an internal bore having a female screw thread 37 of sufficient diameter to allow free passage over the flange 23 of the member 20. The female member 10 has a male thread 19 on the portion 13 cooperable with the female thread 37 of the collet 30 and flange 9 between the hose connection portion 11 and the threaded portion 13. In operation the coupling functions similarly to that described with reference to Fig. 1 except that the locking means are provided by the collet 30 screwing onto the member 10 until the front face of the collet 30 abuts the flange 9. At this point sufficient clearance is available between the flanges 23 and 35 to allow relative rotation of the members 10 and 20.

No constructional materials have been specified since it is evident that any conventional materials normally used for couplings may be employed. The coupling may, for example, be machined from aluminium alloy, brass or stainless steel or moulded from plastics materials.

Although the coupling has as an object the prevention of accidental disconnection between two torsionally rigid hoses its use is clearly applicable to any type of hose which requires a leak-free coupling having the facility of relative rotation.

Claims (5)

1. A coupling for connecting two hoses, the coupling comprising a first tubular member having a female portion and means for joining the member to a hose, a second tubular member having a male portion and means for joining the member to a hose and the male portion being co-operable with the female portion of the first member, sealing means disposed between the female portion of the first member and the male portion of the second member, the two members being held united by locking means such that leakfree relative rotation between the first member and the second member is allowed.

2. A coupling according to claim 1 and wherein the sealing means comprises 'o' rings.

3. A coupling according to either claim 1 or claim 2 and wherein the locking means includes a resiliently biased collet around one tubular member engagable by a bayonet locking action with pegs on or around the other tubular member.

4. A coupling according to either claim 1 or claim 2 and wherein the locking means includes a female screw threaded collet around one tubular member the collet being co-operable with a male screw thread on or around the other tubular member.

5. A hose coupling substantially as hereinbefore described with reference to either Fig.

1 or Fig. 2 of the accompanying drawings.