WO1979001116A1

WO1979001116A1 - Tube coupling

Info

Publication number: WO1979001116A1
Application number: PCT/SE1979/000110
Authority: WO
Inventors: A Bergstedt
Original assignee: Nord Verkstads Ab; A Bergstedt
Priority date: 1978-05-25
Filing date: 1979-05-17
Publication date: 1979-12-27
Also published as: SE411582B

Abstract

Tube coupling for the connection of two tube sections, comprising two collars (3, 4) which in the form of cylindrical sleeves are provided to be united with each tube section. A cylindrical lock sleeve (5) encircles the collars. Coupling saddles (8, 9) with inturned shoulders (10, 11) grip into grooves (12, 13) on the outer side of the collars securing the collars in the axial direction. At least one collar (3) has a front flange (15) defining a front side (l7) of groove (12), said front side (17) having the form of a spherical zone. The corresponding surface (14) on the shoulder (10) gripping into the groove (12) has a corresponding concave shape. Through the design the two tube sections can be turned within a certain angle relative to each other maintaining full sealing action of the coupling.

Description

TUBE COUPLING

The present invention relates to a tube coupling for the connection of two tube sections, comprising two collars which in the form of cylindrical sleeves are provided to be united with each tube section. More particularly does the invention comprise a cylindrical lock sleeve encircling the collars, sealing means between the collars and the lock sleeve, and coupling saddles in the form of sectors of a cylindrical sleeve with inturned shoulders gripping into grooves on the outer sides of the collars, relatively locking the collars in the axial direction.

Tube coupling of the above mentioned type are known in the art e.g. through the Swedish patent specification 167 981. These previously known couplings heretofore have got a very limited practical use. Therefore it is an object of the invention to develope the known basic design so that the tube coupling will be a more atractive alternative to conventional design, particularly in those cases where it is desired to be able to turn the two tube sections relative to each other. This object can be achieved therein that the invention is characterized by the attached claims.

Further objects and advantages of the invention will be apparent from the following description of two preferred embodiments with reference to the accompanying drawings, in which

Fig. 1 is a longitudinal section through the tube coupling according to a first embodiment, and

Fig.2 is a longitudinal section through the tube coupling according to a second embodiment of the invention. Referring first to Fig.l the tube sections which are to be united have been generally shown as 1 and 2, respectively. Each tube section 1 and 2 is connected with a cylindrical collar 3 and 4, respectively, through butt welding. A cylindrical lock sleeve 5 is provided in a manner per se to encircle the collars 3 and 4 and is secured in its position by means of two safety rings 6 and 7, so called Seger-rings which through spring action are removably provided in grouves 6' and 7', respectively, in the outer sides of the collars 3 and 4. In order to hold the tube coupling together there are besides cylindrical lock sleeve 5 provided two coupling saddles 8 and 9. Each coupling saddle 8 and 9 is designed as a semi-cylindrical sleeve with inturned shoulders 10 and 11 gripping into grooves 12 and 13 on the outer side of the collars 3 and 4, respectively. The groove 13 provided on collar 4 together with the corresponding shoulder 11 on saddles 8 and 9 are designed in the same manner as according to the design disclosed in the Swedish patent specification No 167 981. This implies that the shoulders 11 are completely straight and completely fill up groove 13 in collar 4. Shoulder 10, however, on saddles 8 and 9 has a deviating design. Thus that surface 14 in shoulder 10 which is turned towards the other shoulder 11 on the same coupling saddle is designed sphericall concave. Further shoulder 10 narrows inwards, i.e. towards the central axis of the coupling. Finally the radial length of shoulder 10 is so short that a space is formed between the inner edge of shoulder 10 and the outer side of collar 3 in the region of the groove 12.

The front portions of collar 3 and collar 4 form two flanges 15 and 16, respectively. Flange 16 is designed in the same manner as the corresponding detail in the coupling according to the Swedish patent specification No 167 981. Flange 15 on collar 3, however, is designed in a manner significant for this invention. Thus the inner side of flange 15, which means that side which is turned in towards groove 12, is designed as a spherical segment 17 having the same radius as the spherical surface 14 on shoulder 10. This implies that collar 3 and hence the tube section 1 can be turned within certain limits with maintained circumferantial contact between shoulder 10 and flange 15 through spherical surface 14 and 17. In order to make this turning possible without deforming any parts of the coupling further the front edge of flange 15 is bevelled - the bevel being shown as 18 as well as the part of collar 3 abutting against the cylindrical coupling sleeve 5. The latter bevelled surface has been shown as 19. In order that the coupling may not play there in further provided a gasket

20 of resilient material, suitably rubber, in groove 12 on the outer side of shoulder 10. Gasket 20 has the form of a ring which widens outwards. Further sealing means in the form of sealings rings - o-rings -

21 and 22 are provided in grooves 23 and 24, respectively, in a manner known per se on the outer sides of collars 3 and 4. The reason why gasket 20 is designed so that it widens outwards in that it therethrough better can compensate for uncymmetrical compression when tube sections 1 and 2 are turned relative to each other, and that gasket 20 therethrough may serve as a temporary securing means form the. coupling saddles 8 and 9 when the tube coupling is beeing assembled.

Fig. 2 shows a coupling in which the coupling members on each tube section 3' and 4' have been designed completely cymmetrically and in accordance with the principles for tube section 3 in Fig.1. As compared to the coupling shown in Fig.l there is also that difference that flange 10' and hence the corresponding flange 11' have straight outer sides, i.e. outer sides coincident with radial sections of the coupling at the same time as gaskets 20' and 20'' have been given a flat side against 10' and 11', respectively, while the opposite surface is bevelled so that the gasket also in this case widens outwards.

Claims

1. Tube coupling for the connection of two tube sections, comprising two collars (3,4) which in the form of cylindrical sleeves are provided to be united with each tube section (1,2), a cylindrical lock sleeve (5) encircling the collars, sealing means (21,22) between the collars and the lock sleeves, and coupling saddles (8,9) in the form of sectors of a cylindrical sleeve with inturned shoulders (10,11) gripping into grooves (12,13) on the outer side of the collars relatively securing the collars in the axial direction, c h a r a c t e r i z e d in that at least the collar (3) provided for one of the tube sections (1) has a front flange (15) defining a front side (17) of groove (12) in the outer side of the collar, said front side (17) having the form of a spherical zon, and that the corresponding surface (14) on the shoulder (10) gripping into the groove (12) has a corresponding concave shape.

2. Tube coupling according to claim 1, c h a r a c t e r i z e d in that a resilient gasket (20) is provided outside the shoulder (10) in the groove (12) on the outer side of the collar (3).

3. Tube coupling according to claim 2, c h a r a c t e r i z e d in that the gasket (20) widens outwards.

4. Tube coupling according to any of claims 1 - 3, c h a r a c t e r i z e d in that the front surface (18) on the flange (15) in the front end of the collar (3) is bevelled.

5. Tube coupling according to claim 4, c h a r a c t e t i z e d in that also the surface (19) of the collar (3) turned against the cylindrical lock sleeve (5) is bevelled.

6. Tube coupling according to any of claims 1 - 5, c h a r a c t e r i z e d in that only one of the tube sections which are intended to be united is provided with said spherical surface, while the corresponding members connected to the other tube sections are straightly formed.

7. Tube coupling according to any of claims 1 - 5, c h a r a c t e r i z e d in that the tube coupling is cymmetrically designed with reference to the members connected to each tube section.