GB2029537A

GB2029537A - Universal joint for fluid conduits

Info

Publication number: GB2029537A
Application number: GB7924077A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-07-14
Filing date: 1979-07-11
Publication date: 1980-03-19
Also published as: GB2029537B

Abstract

A universal joint for a fluid conduit comprises a pair of tubular connectors (1, 2) joined by a bellows (3) and capable of articulation wherein, to restrain movement apart of the connectors (1, 2), a tubular sleeve (29) is provided to extend over the joint between the connectors (1, 2) and bearing means are provided between end portions of the sleeve (29) and the respective connectors (1, 2), the bearing means comprising, for each connector, diametrically opposed pivotable connectors with the connections on one connector (1) angularly displaced by 90 DEG from the connections on the other connector (2). The connections may be provided between radially inwardly directed continuous flanges (29a) or brackets (30) on the sleeve (29) and radially outwardly directed flanges (32) or brackets on the connectors (1, 2) and rollers (31) may be provided between the brackets or flanges and have locating means (33, 34, 35). <IMAGE>

Description

SPECIFICATION Universal joint for fluid conduits The invention relates to a universal joint for a fluid conduit and particularly to a bellows sealed universal joint capable of angulating through 360'.

Such a joint can be used in a pipe or ducting carrying a fluid, particularly air, for example ducted hot air in an aircraft, to cater for thermal expansion, installation tolerances and vibration.

When an internal pressure is applied to bellows an end load is produced which must be restrained to prevent stretching of the bellows and damage to adjacent structures.

The purpose of this invention is to provide a suitable restraining mechanism whilst permitting the required angulation.

According to the invention a universal joint for a fluid conduit comprises a pair of tubular connectors joined by a bellows and to be inserted in the conduit to connect together two adjacent parts of the conduit, wherein, to restrain movement apart of the connectors of the pair of connectors, a tubular sleeve is provided to extend over the joint between the connectors and bearing means are provided between end portions of the tubular sleeve and the respective connectors, the bearing means comprising, for each connector, diametrically oppositely disposed pivotable connections with said connections on one of the connectors angularly displaced by 90 from such connections on the other connector.

Preferably the connections comprise radially inwardly projecting means at each end of the tubular sleeve and radially outwardly projecting means for each connector to bear against said radially inwardly projecting means.

The radially inwardly and radially outwardly projecting means may comprise continuous flanges or brackets on the tubular sleeve and the connectors respectively.

Advantageously the radially inwardly extending means bears against said radially outwardly extending means with the interposition therebetween of bearing rollers. Preferably the bearing rollers have oppositely directed locating arms thereon, one of the locating arms engaging between locating flanges on an annular bearing ring secured to the respective connector and forming said radially outwardly projecting means and the other of the locating arms engaging in cut-outs in the radially inner edge of a flange forming said radially inwardly directed means. The radially inner edge can be a chordally extending portion of a continuous flange or of a bracket forming said radially inwardly extending means.

Alternatively the radially inwardly directed means comprise trunnions mounted in said tubular sleeve. Bearing bushes may be provided on the trunnions.

Inwardly projecting pins may be provided secured to the tubular ring and extending, with clearance, into apertures in overlapping extensions of the tubular connectors.

The invention is diagrammatically illustrated by way of example in the accompanying drawings, in which: Figure 1 is a fragmentary sectional elevation of a first embodiment of a universal joint for a fluid conduit according to the invention and incorporating a roller mechanism; Figure 2 is a fragmentary sectional elevation of a second embodiment of the invention incorporating a bearing bush mechanism; Figure 3 is a fragmentary sectional elevation of a third embodiment of the invention incorporating a sliding plate mechanism; Figure 4 shows a fragmentary view taken in the direction of arrow IV of Fig. 3; Figure 5 is a fragmentary sectional elevation of a fourth embodiment of the invention including bearing locating means; and Figure 6 is a fragmentary view taken in the direction of arrow VI of Fig. 5.

Each of the illustrated embodiments has connectors 1 and 2 to be secured to the adjacent ends of pipes or lengths of ducting to be joined and through which fluid is to pass. The connectors 1 and 2 are formed with spherically shaped portions 1 a and 2a, with the portion 2a sliding or angulating within the portion 1 a to form a "knuckle joint" and a bellows 3 connected at its opposite ends to the connectors 1 and 2 respectively to form a sealed connection therebetween. End loads, resulting from pressure in the bellows 3, are restrained in the embodiment of Fig. 1 by a tubular member 5 which extends over the portions 1 a and 2a and has an inturned flange 5a at one end. At its other end the tubular member 5 has a ring 6 or a pair of brackets of angular section welded or otherwise firmly fixed thereto, the ring 6 or each, of the brackets having an inturned flange 6a.A ring 7 or a pair of angular brackets with a flange or flanges 7 a extending parallel to the flange 6a is or are welded or otherwise secured on the connector 1. A pair of diametrically oppositely located bearing rollers are mounted between the flanges 6 a and 7 a. A further pair of bearing rollers (not shown) similar to the bearing rollers 4 are provided between the flange 5a and flanges or a flange, equivalent to the flanges or flange 7a, on a pair of brackets or a ring similar to the ring 7 secured on the connector 2, the positions of such further pair of bearing rollers being diametrically opposite one another and 90 offset from the rollers 4.

The bearing rollers 4 and further bearing rollers absorb end loads resulting from pressure in the bellows 3 and provide means of angulating the joint, during angulation the bearing rollers oscillating between the flanges between which they are located. The ring 6 could be omitted, a further flange, corresponding to the flange 5a, being provided at the position of the flange 7a on the ring 5.

In the embodiment of Fig. 2, a tubular ring 1 5 has a pair of inwardly extending trunnions 9 diametrically oppositely disposed in each end thereof with the opposite ends 90 out of alignment. Bearing bushes 8 are rotatable on the trunnions 9 and bear on flanges 1 7a of respective brackets 1 7 secured to the connectors 1 and 2.

In the embodiment of Figs. 3 and 4, a tubular ring 25 has angular section brackets 26 welded thereto, the brackets 26 each having a radially inwardly extending flange 26a. The flanges 26a bear against radially extending flanges 27a of respective brackets 27 welded to the connectors 1 and 2, the brackets 27 being provided in pairs at diametrically opposed positions at each end with the opposite ends 90 out of alignment.

Two pairs of inwardly directed pins 28 are secured to the ring 25 and extend, with clearance, into apertures in the portions 1 a and 2a of the connectors 1 and 2 to assist angulation.

The pins 28 are also capable of restraining the joint in the unlikely event of the primary structure failing. Inturned flanges could be provided at the ends of the ring 25 instead of the brackets with the flanges 26a if preferred.

In the embodiment of Figs. 5 and 6, a tubular ring 29 has its ends spun down to form flanges 29a over retaining angles 30 to locate rollers 31 between an annular bearing ring 32, welded to the respective connector 1 and 2, and the retaining angle 30.

The rollers 31, have involute shaped locating arms 33, to engage between locating flanges 34, on the bearing rings 32 and slots 35, formed by cut-outs in chordally extending inner edge portions 30a of the retaining angles 30 to ensure controlled movement during angulation of joints.

Alternatively the two bearing rings 30 could be replaced by four separate segments, welded to the connectors 1 and 2.

A joint according to the invention can have a simple bellows-sealed "knuckle type" joint restrained by a rolling or sliding mechanism; a variable bellows bore depending on flow requirements; low bending moments under pressure; and a secondary load carrying capability through the pins 28 which provide a "fail-safe" feature in the unlikely event of the primary structure failing.

It can also have a limited controlled leak to ambient between the portions 1 a and 2a should the bellows 3 fail; full protection for the bellows 3 against external damage; easy assembly with the bellows 3 previously installed in the connections 1 and 2; low cost; and no torque load on the bellows.

Claims

1. A universal joint for a fluid conduit comprising a pair of tubular connectors joined by a bellows and to be inserted in the conduit to connect together two adjacent parts of the conduit, wherein, to restrain movement apart of the connectors of the pair of connectors, a tubular sleeve is provided to extend over the joint between the connectors and bearing means are provided between end portions of the tubular sleeve and the respective connect tors, the bearing means comprising, for each connector, diametrically oppositely disposed pivotable connections with said connections on one of the connectors angularly displaced by 90 from such connections on the other connector.

2. A universal joint according to claim 1, in which said connections comprise radially inwardly projecting means at each end of the tubular sleeve and radially outwardly projec ting means from each connector to bear against said radially inwardly projecting means.

3. A universal joint according to claim 2, in which said radially inwardly projecting means and/or said radially outwardly projec ting means comprises a continuous flange.

4. A universal joint according to claim 2, in which said radially inwardly projecting means and/or said radially outwardly projec ting means comprises brackets secured to said tubular sleeve and said connectors respec tively.

5. A universal joint according to any one of claims 2 to 4, in which said radially in wardly extending means bears against said radially outwardly extending means with the inter-position therebetween of bearing rollers.

6. A universal joint according to claim 5, in which the bearing rollers have oppositely directed locating arms thereon, one of the locating arms engaging between locating flanges on an annular bearing ring secured to the respective connector and forming said radially outwardly projecting means and the other of the locating arms engaging in cut outs in the radially inner edge of a flange forming said radially inwardly directed means.

7. A universal joint according to claim 7, in which said radially inner edge is a chordally extending portion of a continuous flange or a bracket forming said radially inwardly extend ing means.

8. A universal joint according to any one of claims 2 to 4, in which said radially in wardly directed means comprise trunnions mounted in said tubular sleeve.

9. A universal joint according to claim 8, including bearing bushes mounted on said trunnions.

10. A universal joint according to any one of claims 1 to 9, including inwardly directed pins secured to the tubular ring and extend ing, with clearance, into apertures in overlap I ping extensions of the tubular connectors.

11. A universal joint for a fluid conduit substantially as hereinbefore described and illustrated with reference to Fig. 1, Fig. 2, Figs. 3 and 4 or Figs. 5 and 6 of the accompanying drawings.