WO1993002314A1

WO1993002314A1 - Hose end fitting and assembly

Info

Publication number: WO1993002314A1
Application number: PCT/GB1992/001271
Authority: WO
Inventors: John Stuart Williams
Original assignee: Dunlop Limited
Priority date: 1991-07-24
Filing date: 1992-07-13
Publication date: 1993-02-04
Also published as: AU2279492A; GB2271823A; GB9115962D0; GB2258507A; HU9400189D0; GB2258507B; EP0595874A1; GB9324997D0

Abstract

A hose end fitting (10) for location in an end of a multi-layer type hose comprises a tubular support member (11), at least one retaining ring (13) axially slidable along the support member (11) during fabrication of a hose body around the end fitting and stop means (14) to prevent movement of the retainer ring (13) along the whole of the axial length of the support member, said retainer ring (13) having an outwardly facing surface (19) which extends axially and radially outwardly as considered in the axial direction in which said stop means (14) prevents axial movement of the retainer ring.

Description

HOSE EttD FITTING AND ASSEMBLY

This invention relates to a hose assembly and an end fitting for a hose assembly comprising an end fitting and a multi-layer, typically reinforced, hose.

Particularly for large diameter hose assemblies the weight of end fittings can be considerable. Apart from being inconvenient when handling the hose assembly, the weight of the end fittings causes potential problems in the case of hoses used offshore, particularly offshore floating type hose lines, since additional buoyancy material needs to be incorporated in the hose or associated with the hose assembly to counteract the weight of the end fittings.

In conventional heavy duty hose assemblies great care is needed to ensure that the respective layers of the hose are anchored effectively to an end fitting and this in turn often leads to a requirement for the end fitting to comprise a spigot portion of relatively complex shape. Apart from increasing manufacturing costs, this also tends to increase the weight of the end fitting.

It is an object of the present invention to provide a hose end fitting and a hose assembly in which the aforedescribed difficulties are mitigated or overcome.

In accordance with one of its aspects the present invention provides a hose end fitting for location in an end of multi-layer type hose, said end fitting comprising a tubular support member, at least one retaining ring axially slidable along the support member during fabrication of a hose body around the end fitting and stop means to prevent movement of the retainer ring along the whole of the axial length of the support member, said retainer ring having an outwardly facing surface which extends axially and radially outwardly as considered in the axial direction in which said stop means prevents axial movement of the retainer ring. The retainer r ng may be cf a solid type construction and have a radially inwardly facing surface which is axially aligned with said outwardly facing surface and is of a cylindrical or other shape which is a close sliding fit over an outwardly facing surface cf the support tube.

Alternatively the retainer ring may have a radially inwardly facing surface which extends axially and radially outwardly as considered in said axial direction in which said stop means prevents axial movement of the retainer ring.

The retainer ring may have a tail portion, typically of substantially uniform cross-sectional shape, and which extends from a radially inner edge of said outwardly facing surface of the retainer ring in an axial direction opposite that in which said stop means prevents axial movement of the retainer ring. The tail portion may be of a tubular form for close sliding contact over the outer surface of the (generally cylindrical) tubular support member. The tail portion may be discontinuous, e g it may be provided with fenestrations thereby to reduce weight and also provide in a hose assembly a mechanical interlock with polymeric material of the hose.

The invention is not confined to provision of a single retainer ring. Two or more retainer rings may be provided on the tubular support member of the end fitting.

The tail portion of a retainer ring may be of a length selected to enable it to act as a spacer whereby it determines the minimum axial separation of the outwardly facing surfaces of a successive pair of retainer rings.

It is not essential that a retainer ring has a tail portion in order to maintain a minimum separation. The hose end fitting additionally may comprise a tubular spacer which is independent of a retainer ring but mav be arran ed between a Dair of successive retainer rings to determine a minimum axial separation.

The stop means may be a projection such as an annular formation provided at or near an axial end of the support member and may act also as an end rib profile over which a hose lining layer is applied.^' A retainer ring may be axially spaced at its radially inner portion from said rib profile by means of a tubular spacer or like spacer component.

In an alternative construction the stop means may be comprised by one or more radially outwardly extending projections formed on the outer surface of the tubular support member and arranged for direct abutment by a retainer ring.

In a preferred construction the tubular support member is provided with an end rib profile which as considered in longitudinal section co-operates with the or the nearest retainer ring to define a restrictive (annular) neck region. Thus hose liner material which extends through that neck region to lie in a relatively enlarged spacing between the retainer ring and outer surface of the support member (or a spacer component if provided) will tend to be held captive. Forces tending to pull the liner axially will result in the end region of the liner primarily tending to be compressed in contrast to the conventional hose end fitting configuration in which the liner primarily tends to be subject to a tearing action under axial load.

The hose end fitting may be of a flanged type construction and have a flange section at one end of the tubular support member, either formed integrally therewith or interconnected for example by welding. In the manufacture of a hose end fitting in accordance with the present invention and of a flanged type, the retainer ring(s) may be fitted to a tubular support member subsequent to provision of a flange or stop means, and prior to provision respectively of the other of the flange and stop means.

The retainer ring may have an axially and radially outwardly extending surface which in cross-section is rectilinear, i e to provide a frusto-conical shaped surface. Alternatively it may for example be of a curved profile in cross-section.

If the retainer ring is of a kind having both inwardly and outwardly facing surfaces which each extend both axially and radially it may be of a material and construction such that radially inwardly acting forces of a surrounding hose body tend to deform the retainer ring thereby to transmit compressive forces to hose body material lying radially inwards of the radially inwardly facing surface. In the case of an end fitting having the aforementioned end rib profile that defines a restrictive neck region any such deformation of the retainer ring will tend to close the neck region and thereby, in use, enhance the compressive effect on hose material held captive by that neck region.

The present invention further provides a hose assembly comprising a multi-layer hose and a hose end fitting of the invention, wherein a first layer of the hose terminates at said retainer ring and another layer extends axially beyond said first layer to lie over the outwardly facing surface of the retainer ring.

The hose of the assembly may contain an embedded reinforcement for example of metallic material or of other materials such as polyester and rayon. A layer of reinforcement may be arranged to substantially directly overlie an outwardly facing surface of a retainer ring.

The layer of material extending over the outwardly facing surface may incorporate a local restraining assembly, for example a helically wound wire, axially aligned with the retainer ring.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings in which:- Figure 1 is a side view, half in longitudinal section, of a hose end fitting in accordance with the present invention; Figure 2 shows part of the hose end fitting in longitudinal section in a condition ready for assembly with a hose during ^' building of the hose, and Figure 3 shows part of a hose assembly comprising the fitting of Figures 1 and 2 and a hose body. A hose end fitting 10 comprises a generally cylindrically shaped support member spigot 11 to one end of which a flange 12 is welded.

Two retainer rings 13 are provided on the spigot 11 and are held captive by a circumferentially extending stop ring 14 welded around the spigot, at a position spaced inwards its end 15 furthest from the flange 12. Additionally an end rib 16 is welded around the spigot at the extreme end 15 to act as a stress relieving profile at the point where a subsequently applied hose lining layer is in transition from being radially inwardly unsupported to being compressed against the radially outer surface of the spigot.

Each retainer ring 13 comprises a retainer portion 17 and a spacer portion 18. The retainer portion is of a frusto-conical shape to define outwardly and inwardly facing surfaces 19,20 which each extend axially and radially outwardly as considered in an axial direction from the flange to- the end 15.

The spacer portion 18 is integral with the retainer portion and is of a cylindrical form which is a close sliding fit over the radially outer surface of the spigot.

The axial length of the spacer portion associated with the retainer ring nearest to the end 15 is selected to provide a desired axial spacing between the two retainer rings thereby to locate therebetween an end of a hose layer, typically a reinforced layer. The axial length of the spacer portion of the other retainer ring for convenience corresponds with that of the ring nearest the end 15, thereby to avoid the need to provide retainer rings of two different constructions, and risk incorrect positioning of differently dimensioned rings, but it will be appreciated that if desired and particularly to further minimise weight the retainer ring furthest from the end 15 may have a shortened spacer portion or comprise only the retainer portion.

The aforedescribed retainer rings typically are formed from steel and may be shaped by taking a length of cylindrical tube which is then subject to cold rolling to create a bell-end shape, thus providing the frusto-conical shape of the retainer portion 17. Alternatively, however, the retainer ring may be constructed using other techniques such as casting or moulding, and may be of a material other than metal.

Use of the aforedescribed end fitting to manufacture a hose assembly will now be described with reference also to Figure 3.

Subsequent to conventional operations of de-greasing, grit blasting and chemical pre-treatment the end fitting is aligned with a hose building mandrel (not shown), with its end 15 adjacent an end of that mandrel. The retainer rings are then slid towards the flanged end and hose lining material 30 is applied around the hose mandrel and over the end of the spigot, to cover the end rib 16 and terminate adjacent the stop ring 14. The conventional skirt layers 31 are then applied to the end region of the hose, these also terminating at the end fitting in proximity to the stop ring 14. The outward slope provided by the skirt layers and lining layer is arranged to complement the profile of the radially inwardly facing surface 20 of the retainer ring nearest that end of the spigot. That retainer ring is then slid axially into contact with the end of the part-formed hose and urged axially further in that direction by means of a suitable tool acting between the ring and flanged end 12 of the hose fitting thereby to compress the ends of the layers of the part-formed hose.

A reinforcement layer 32 comprising metallic reinforcing elements embedded in rubber is then applied around the hose mandrel and to extend over the outer surface 19 of the retainer ring nearest the end 15 of the spigot. The reinforcement is then held radially against the outer surface of the retainer ring by means of a binding provided by a helically wound wire 33. Additional filler rubber is then provided as necessary to create a sloping outer surface complementary to the inward facing surface of the second retainer ring 13 which is then slid into place. This is then urged axially towards the end 15 to compress the end of the aforedescribed first reinforcement layer 32, and the manufacturing process is repeated to apply a second reinforcement layer 34 that extends over the second retainer ring. Outer component layers 35,36 of the hose and finally a cover layer 37 are then applied.

Claims

CLAIMS :

1. A hose end fitting for location in an end of a multi-layer type hose, said end fitting comprising a tubular support member, at least one retaining ring axially slidable along the support member during fabrication of a hose body around the end fitting and stop means to prevent movement of the retainer ring along the whole of the axial length of the support member, said retainer ring having an outwardly facing surface which extends axially and radially outwardly as considered in the axial direction in which said stop means prevents axial movement of the retainer ring.

2. A hose end fitting according to claim 1 wherein the retainer ring has a radially inwardly facing surface which extends axially and radially outwardly as considered in said axial direction in which said stop means prevents axial movement of the retainer ring.

3. A hose end fitting according to claim 1 wherein the retainer ring has a radially inwardly facing surface which is axially aligned with said outwardly facing surface and is of a shape which is a close sliding fit over an outwardly facing surface of the support tube.

4. A hose end fitting according to any one of the preceding claims wherein the retainer ring has a tail portion which extends from a radially inner edge of said outwardly facing surface of the retainer ring in an axial direction opposite that in which said stop means prevents axial movement of the retainer ring.

5. A hose end fitting according to claim 4 wherein said tail portion is of a tubular form for close sliding contact over an outwardly facing surface of the support tube.

6. A hose end fitting according to claim 4 or claim 5 wherein at least in part said tail portion is circumferentially discontinuous.

7. A hose end fitting according to any one of claims 4 to 6 wherein said tail portion has a length selected to determine the minimum axial separation of a successive pair of retainer rings.

8. A hose end fitting according to any one of the preceding claims and comprising a tubular spacer provided between two retainer rings to maintain a minimum axial separation of said rings.

9. A hose end fitting according to any one of the preceding claims wherein said stop means is comprised by a radially outwardly extending projection on the outer surface of the tubular support member.

10. A hose end fitting according to claim 9 wherein the retainer ring is arranged for direct abutment with said stop means.

11. A hose end fitting according to claim 9 wherein the retainer ring is spaced axially from said stop means by a spacer component.

12. A hose end fitting according to any one of the preceding claims wherein the tubular support member is provided with an end rib which as considered in longitudinal section of the fitting co-operates with a retainer ring to define a restrictive neck region.

13. A hose end fitting according to claim 12 when dependent on claim 11 wherein said end rib profile serves as said stop means.

14. A hose end fitting constructed and arranged substantially as hereinbefore described with reference to the accompanying drawings.

15. A hose assembly comprising a multi-layer hose and a hose end fitting according to any one of the preceding claims wherein a first layer of the hose terminates at said retainer ring and another layer extends axially beyond said first layer to lie over the outwardly facing surface of the retainer ring.

16. A hose assembly according to claim 15 wherein the layer of material extending over the outwardly facing surface of the retainer ring is held against said retainer ring by a local restraining assembly.

17. A hose assembly according to claim 15 and constructed and arranged substantially as hereinbefore described.