AU588886B2

AU588886B2 - Hose coupling

Info

Publication number: AU588886B2
Application number: AU58609/86A
Authority: AU
Inventors: Peter John Snelling
Original assignee: Vinidex Tubemakers Pty Ltd
Current assignee: Vinidex Tubemakers Pty Ltd
Priority date: 1985-05-06
Filing date: 1986-05-06
Publication date: 1989-09-28
Anticipated expiration: 2006-05-06
Also published as: AU5860986A

Description

HOSE COUPLING ^•

This invention relates to a fitting intended to provide a sealing connection between a tube and the fitting.

5. This can variously be described as a hose coupling or a fitting.

The problem to which this invention is directed is to provide a fitting of this type which can provide both a liquid seal and means for holding the tube within 10. the fitting where the fitting as a whole is an integral moulding.

The invention can accordingly be said to reside in a fitting facilitating a sealing connection with a tube to provide a liquid seal, the fitting having

15. an aperture to receive a tube therein, the fitting being comprised of a plastics material and having a circumferentially continuous inwardly extending lip integral with the housing of the fitting, the lip being attached to the housing by a portion of

20. reduced thickness and adapted thereby and by the position of such reduced thickness portion, to be pivotal about such portion of reduced thickness.

In preference the lip has an innermost face which is of continuous constant shape.

25. In preference the fitting is integrally formed of a plastics material of a type such that the portion of reduced thickness will provide a pivotal effect for the inner portion of the lip while being sufficiently stiff to substantially resist deformation about any

30. axis radially aligned with respect to the fitting, while being able to expand and contract circumferentially. By having the lip having a cross-sectional shape of a wedge, provides for this feature of being able to resist buckling deformation, while at the same 5. time being able to expand and contract circumferentially in concert with pivotal action about the portion of reduced thickness.

In order to limit the extent to which the pivotal action can extend, there are provided a plurality 10. of segmented tails secured to the lip.

By appropriate selection of the shape of the lip, the location and shape of the tails, and these in conjunction both with the plastics type and the shape and type of tube to be secured, it has been

15. found that a very excellent fitting being a one off integral mould, can be provided which can provide both an effective liquid seal as well as strong mechanical engagement especially when there is internal liquid pressure which can have the effect of causing the

20. lip to engage more strongly the external surface of the gripped tube.

Significant savings are made because there is no subsequent assembly necessary, for instance, a sealing ring or a tightening ring as has hitherto 25. been necessary. Furthermore, in use, the tube needs only to be inserted into the fitting to be secured thereto. This can provide significant savings in respect of the time taken to install an irrigation system.

30. For a better understanding of the invention it will now be described with respect to the preferred embodiment which shall be described with the assistance of drawings in which :- FIG. 1 is an end view of a fitting according to the embodiment;

FIG. 2 is a cross-sectional view along lines 2-2 of Fig. 1;

5. FIG. 3 is the same view of the fitting as in Fig. 2 incorporating, however, an approaching tube;

FIG. 4 is a detail from Fig. 3 showing the arrangement upon further entry of the 10. tube; and

FIG. 5 is the same detail as in Fig. 4 showing the arrangement upon an expected attempt to withdraw the tube and when under liquid pressure.

15. Referring in detail to the drawings, a lip 1 is shown as a peripheral portion within the fitting 2 having an innermost sharp corner at 3 which is of lesser diameter than an outermost corner at 4.

The shape of the lip 1 is continuous and consistent 20. around the annular path and provides there a continuous inner face defining a frustro-conical area at 5.

The fitting 2 is intended for a tube of circular cross-section and accordingly has itself a circular cross-section having a central axis at 6.

25. The lip 1 has an inner face at 7 inclined at 18° to the axis 6. The sides of the lip 1 at 8 and 9 are inclined at 75° to the axis 6. There is a portion of reduced thickness at 10 which thereby connects the lip 1 to the housing 2, the thickness of which is selected together with the shape of the lip, and the selection of plastics 5. material, so that when an appropriate tube is inserted, the sharp corner 3 will be caused under compression to expand and rotate inwards and allow for the entry of the tube without excessive resistance, also without undue buckling.

10. The buckling can be said to be deformation about an axis orientated radially with respect to the central axis 6 of the fitting 2.

Accordingly by providing the so-called triangular or wedge shape in cross-section of the lip 1, there 15. is provided this inner stiffness while having this connected to a portion of the housing through a portion of significantly reduced thickness at 10, allows adequate pivotal freedom.

It will be very clear that the characteristics 20. of both the plastics material, the thickness, the respective angles and the shape of each part, all go toward making this fitting work for a selected tube.

It is a feature as shown in the drawings that 25. the fitting is integrally moulded from plastics material and according to this embodiment this is selected from a plastics material having an elongation at break of at least 200%.

Such a material is a polyester sold commercially 30. under the trade mark "Valox 325" which has an elongation at break of 3007. as well as good tensile and compressive strength and low creep. Such a material is appropriate for manufacturing a fitting according to this invention where a tube circular cross-section is made from linear low density polythene.

5. In order to ensure that the lip 1 with the entry of a tube does not ensnare and go past a preferred position, there are provided a plurality of tails 11 which are separated by slots 12 each of the tails being integrally secured to and forming part of the 10. lip 1, but the segmentation allows the relative movement both compression and expansion of the lip 1, together with the pivoting about the portion of reduced thickness at 10, to occur without undue restriction.

The effect of each of the tails is therefore 15. in the one instance to limit, with entry of a tube 13 the extent of forward pivoting of the lip 1 as is shown in Fig. 4, and in the instance of attempted removal of the tube 13, as shown in Fig. 5, the tail can eventually engage against portion 14 of the fitting 20. I- the shape and position of which is selected so that the sharp corner 3 will not have past further toward an entry into the fitting 1 than the pivot axis nominally shown at 15 about which it pivots.

It will now be seen from the description of 25. the preferred embodiment that by provision of a lip portion which is integrally attached to the housing but is sufficiently stiffened to resist deformation but nonetheless because of the selection of plastic and the shape will be able to expand and contract 30. modestly, while, however, allowing pivotal freedom about the portion of reduced thickness, allows for pivotal freedom providing a very effective sealing and gripping effect when required.

The remainder of the fitting 2 includes internal thread portion 16 and protrusions 17 by which the 5. fitting 2 can be held against rotational action to secure a further fitting in the threaded portion.

Such additional features, however, are entirely optional.

In respect of each tail 11, the inner surface

10. 18 is alliiggnneedd ttoo bbee 11°° ^'l. ess flared than the inner surface 7 of the lip 1.

The angular relationships are otherwise as shown in the drawings in respect of the preferred embodiment, which is shown approximately twice full-size 15. for a conventional fitting.

The naturally existing position as shown in Figs. 1, 2 and 3 shows that the innermost face of the lip 1 is shaped and positioned so as to provide an inwardly tapering shape when without a tube therein 20. as in Figs. 4 or 5.

It is noted that the frustro-conical shape 5 defined by the inner face of the lip 1 can according to a broader concept define an angle which is within the range of 28° to 46°.

25. In the preferred embodiment this is 36°.

Claims

1. A fitting facilitating a sealing connection with a tube to provide a liquid seal, the fitting having an aperture to receive a tube therein, the fitting being comprised of a plastics material and

5. having a circumferentially continuous inwardly extending lip integral with a housing of the fitting, the lip being attached to the housing by a portion of reduced thickness and adapted thereby and by the position of such reduced thickness portion to be pivotal about such 10. portion of reduced thickness.

2. A fitting facilitating a sealing connection with a tube to provide a liquid seal, as in claim

1 further characterised in that the lip has an inner most face which is of continuous and constant shape.

3. A fitting facilitating a sealing connection with a tube to provide a liquid seal, as in either of claims 1 or 2 further characterised in that the innermost face of the lip is shaped and positioned

5. so as to provide an inwardly tapering shape when without a tube therein.

4. A fitting facilitating a sealing connection with a tube to provide a liquid seal, as in any one of the preceding claims further characterised in that the lip has tail segments extending from the

5. lip toward an entry end of the fitting adapted to move with the lip and to limit ultimate relative movement of the lip.

5. A fitting facilitating a sealing connection with a tube to provide a liquid seal, as in any one of the preceding claims further characterised in that the lip has a sharp inner corner positioned

5. and adapted so as to provide for an increasing gripping effect upon withdrawal of a tube held within the fitting. 6. A fitting facilitating a sealing connection with a tube to provide a liquid seal, as in preceding claim 4 further characterised in that each tail segment has an inner face substantially aligned with the

5. inner face of the lip.

7. A fitting facilitating a sealing connection with a tube to provide a liquid seal, as in preceding claim 4 further characterised in that each tail segment has an outer face shaped and positioned with respect

5. to the lip and the housing so as to provide a pivotal limit with respect to the sharp corner of the lip such that this will be restricted from moving further toward the entry end of the fitting than the pivot axis about which it pivots.

8. A fitting facilitating a sealing connection with a tube to provide a liquid seal, according to any one of the preceding claims further characterised in that an inner face of the lip defines a frustro-conical 5. shape the angular relationship of the sides of which define therebetween an angle in the range of 28 to 46°.

9. A fitting facilitating a sealing connection with a tube to provide a liquid seal, as in the last preceding claim further characterised in that the angle is approximately 36 .

10. A fitting facilitating a sealing connection with a tube to provide a liquid seal, as in any one of the preceding claims further characterised in that the lip is in the form of a wedge shape in

5. cross-section. 11. An arrangement for facilitating a sealing connection with a tube to provide a liquid seal, comprising the combination of a fitting as characterised in any one of the preceding claims and a tube located

5. within the fitting such that the lip is engaging against the outer surface of the tube providing a sealing engagement thereby between the tube and the fitting.

12. A fitting substantially as described in the specification with reference to and as illustrated by the accompanying drawings.

13. An arrangement comprising, in combination, a fitting together with a tube where the combination is substantially as described in the specification with reference to and as illustrated by the accompanying 5. drawings.

14. A fitting providing for a sealing connection with an appropriately shaped hose, the fitting having a lip which has an innermost portion which is integrally connected to a surrounding housing by a portion of

5. reduced thickness, the fitting being integrally formed of a plastics material of a type such that the portion of reduced thickness will provide a pivotal effect and the inner portion of the lip while being sufficiently stiff to substantially resist deformation about an

10. axis radially aligned with respect to the fitting while being able to expand and contract circumferentially.