GB1602077A

GB1602077A - Tube coupling device

Info

Publication number: GB1602077A
Application number: GB25374/78A
Authority: GB
Original assignee: IMI ENOTS Ltd
Current assignee: IMI ENOTS Ltd
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-11-04
Also published as: DE2922285A1; FR2420077B1; FR2420077A1

Description

(54) TUBE COUPLING DEVICE (71) We, IMI ENOTS LIMITED, formerly Known as Enots Limited, a British Company, of Eastern Avenue, Lichfield, Staffs do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a tube coupling device for releasably securing a tube to a connecting passage within the tube coupling device. Various types of tube coupling device have been proposed for this purpose, for instance the tube coupling device taught in our UK Patent Application No 1576131.

With this construction the tube is gripped by a collet operated by a frusto-conical surface within the body of the coupling device. The collet has an integral tubular collar which extends from the body of the tube coupling device and has an outwardly directed annular flange to facilitate operation of the collet in the direction for disengaging the tube. Such tube coupling devices are frequently used in difficult environments for instance on automatic welding machinery.

in this case the splatter produced by the welding operation tends to fly in all directions and can adhere to the portion of the collar projecting from the body of the coupling device, thereby impeding or completely preventing movement of the collet in the uncoupling direction.

According to the invention a tube coupling device comprises a coupling body having a tubular portion defining an aperture and a terminal end face, a tubular collar supported for axial sliding within the aperture and having one end projecting from the terminal end face, clamping means arranged within the coupling body for detachably securing at tube inserted through the collar to the coupling body, said one end of the collar having an outwardly directed annular flange, and a shroud ring secured to the annular flange and extending with working clearance over the tubular portion of the coupling body. The shroud ring preferably has an inwardly directed annular lip which abuts the side of the annular flange remote from the coupling body. The shroud ring may also be formed with clip means engaging the side of the annular flange adjacent to the coupling body to prevent unintentional removal of the shroud ring. The shroud ring is preferably formed as a pressing from metal sheet, the clip means being in the form of one or more inturned flaps.

The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is an axial section through a tube coupling device showing the shroud ring in position; Figure 2 is a side elevation of the shroud ring; and Figure 3 is a perspective view of the shroud ring showing a marginal portion broken away.

With reference to the drawings a tube coupling device comprises a coupling body 10 having a tubular portion 11 at one end and a threaded connector 12 at the opposite end, external flats 13 being provided for engagement by a spanner. A sealing washer 14 is carried by the coupling body 10 at the base of the threaded connector 12 for sealing against the face of any apparatus into which the threaded connector is fitted.

In this manner internal passage 15 is sealingly connected to the apparatus. The coupling body 10 also defines an internal annular surface 16 which serves as a tube stop and a further internal annular surface 17 which serves to locate a sealing ring 18.

The tubular portion 11 defines a cylindrical aperture 19 and a terminal end face 20 which lies in the plane normal to the axis of the tubular portion 11. Collet teeth 21 are formed on the ends of respective collect arms 22 which are formed integral with a tubular collar 23 supported for axial sliding within the aperture 19. At its free end, the outer surface of each collet arm 22 is formed with a part-conical camming surface 24 engageable with an internal frusto-conical surface 25 of the coupling body 10.

When a tube is inserted through the tubular collar 23 it will spring the collet teeth 21 slightly radially outwards before its end reaches the sealing ring 18. The sealing ring 18 is similarly distended thereby affecting a seal between the outer cylindrical surface of the tube and the coupling body. Axial movement of the tube relative to the coupling body 10 is arrested when its end engages the end-stop provided by internal annular surface 16. When pressure is applied to the interior of the tube, or when an attempt is made to pull the tube away from the coupling body 10, the tube is free to slide axially through the sealing ring 18 but, due to the grip exerted by the collet teeth 21, the tubular collar 23 is also moved axially within the tubular portion 11 until the camming surfaces 24 engage the internal frusto-conical surface 25. Any further relative movement in this direction causes the collet teeth 21 progressively to grip the tube thereby preventing any further withdrawal.

The tubular collar 23 is provided with an outwardly directed annular flange 26 which is used to push the tubular collar 23 axially into the coupling body 10 to prevent engagement of the surfaces 24, 25, thereby enabling the tube to be withdrawn against the slight drag exerted by the sealing ring 18 and the collet teeth 21. The tube coupling device described at this point is already well-known.

It will be noted that, when internal pressure is applied to the tube, or when the tube is pulled relative to the coupling body 10, a gap opens between the side of the annular flange 26 adjacent the coupling body 10. It is this gap which can become blocked by welding splatter or other materials when the tube coupling device is used in difficult environments.

A shroud ring indicated generally by arrow 27 is formed as a single pressing from sheet material such as brass. The shroud ring has an inwardly directed annular lip 28 which abuts against the side of the annular flange 26 remote from the coupling body 10.

The cylindrical wall 29 of the shroud ring has an annular series of inturned flaps 30.

The shroud ring is fitted to the tubular collar 23 by feeding the cylindrical wall 29 over the outwardly directed annular flange 26 until the flaps 30 are resiliently pressed outwards and eventually spring back behind the side of the annular flange 26 adjacent to the coupling body 10 as shown in Figure 1. In this manner the shroud ring is firmly secured to the annular flange with its cylindrical wall extending with working clearance over the tubular portion I I. A particular advantage of the invention is that the tubular collar 23 does not have to be modified in any way to accept the shroud ring 27 and the shroud ring can consequently be provided as an optional feature for tube coupling devices which are to be used in difficult environments.

WHAT WE CLAIM IS: 1. A tube coupling device comprising a coupling body having a tubular portion defining an aperture and a terminal end face, a tubular collar supported for axial sliding within the aperture and having one end projecting from the terminal end face, clamping means arranged within the coupling body, said one end of the collar having tube inserted through the collar to the coupling body, said one of the collar having an outwardly directed annular flange, and a shroud ring secured to the annular flange and extending with working clearance over the tubular portion of the coupling body.

2. A tube coupling device, according to Claim 1, in which the shroud ring has an inwardly directed annular lip which abuts the side of the annular flange remote from the coupling body.

3. A tube coupling device, according to Claim 2, in which the shroud ring is formed with clip means engaging the side of the annular flange adjacent to the coupling body to prevent unintentional removal of the shroud ring 4. A tube coupling device, according to Claim 3, in which the shroud ring is formed as a pressing from metal sheet, the clip means being in the form of one or more inturned flaps.

5. A tube coupling device constructed substantially as described herein and as shown in the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. surface 24 engageable with an internal frusto-conical surface 25 of the coupling body 10. When a tube is inserted through the tubular collar 23 it will spring the collet teeth 21 slightly radially outwards before its end reaches the sealing ring 18. The sealing ring 18 is similarly distended thereby affecting a seal between the outer cylindrical surface of the tube and the coupling body. Axial movement of the tube relative to the coupling body 10 is arrested when its end engages the end-stop provided by internal annular surface 16. When pressure is applied to the interior of the tube, or when an attempt is made to pull the tube away from the coupling body 10, the tube is free to slide axially through the sealing ring 18 but, due to the grip exerted by the collet teeth 21, the tubular collar 23 is also moved axially within the tubular portion 11 until the camming surfaces 24 engage the internal frusto-conical surface 25. Any further relative movement in this direction causes the collet teeth 21 progressively to grip the tube thereby preventing any further withdrawal. The tubular collar 23 is provided with an outwardly directed annular flange 26 which is used to push the tubular collar 23 axially into the coupling body 10 to prevent engagement of the surfaces 24, 25, thereby enabling the tube to be withdrawn against the slight drag exerted by the sealing ring 18 and the collet teeth 21. The tube coupling device described at this point is already well-known. It will be noted that, when internal pressure is applied to the tube, or when the tube is pulled relative to the coupling body 10, a gap opens between the side of the annular flange 26 adjacent the coupling body 10. It is this gap which can become blocked by welding splatter or other materials when the tube coupling device is used in difficult environments. A shroud ring indicated generally by arrow 27 is formed as a single pressing from sheet material such as brass. The shroud ring has an inwardly directed annular lip 28 which abuts against the side of the annular flange 26 remote from the coupling body 10. The cylindrical wall 29 of the shroud ring has an annular series of inturned flaps 30. The shroud ring is fitted to the tubular collar 23 by feeding the cylindrical wall 29 over the outwardly directed annular flange 26 until the flaps 30 are resiliently pressed outwards and eventually spring back behind the side of the annular flange 26 adjacent to the coupling body 10 as shown in Figure 1. In this manner the shroud ring is firmly secured to the annular flange with its cylindrical wall extending with working clearance over the tubular portion I I. A particular advantage of the invention is that the tubular collar 23 does not have to be modified in any way to accept the shroud ring 27 and the shroud ring can consequently be provided as an optional feature for tube coupling devices which are to be used in difficult environments. WHAT WE CLAIM IS:

1. A tube coupling device comprising a coupling body having a tubular portion defining an aperture and a terminal end face, a tubular collar supported for axial sliding within the aperture and having one end projecting from the terminal end face, clamping means arranged within the coupling body, said one end of the collar having tube inserted through the collar to the coupling body, said one of the collar having an outwardly directed annular flange, and a shroud ring secured to the annular flange and extending with working clearance over the tubular portion of the coupling body.

3. A tube coupling device, according to Claim 2, in which the shroud ring is formed with clip means engaging the side of the annular flange adjacent to the coupling body to prevent unintentional removal of the shroud ring

4. A tube coupling device, according to Claim 3, in which the shroud ring is formed as a pressing from metal sheet, the clip means being in the form of one or more inturned flaps.