Clamping device for coupling smooth tubes together in leaktight manner

1. A clamping device for coupling together in leaktight manner two smooth tubes that are disposed end-to-end, the device comprising: a sealing ring that is suitable for clamping around the facing ends of the two tubes, and that has a first free end provided with a first sealing arrangement and a second free end provided with a second sealing arrangement, the first and second sealing arrangements being designed to procure leaktight contact between said free ends when the ring is in a tightened state, the device further comprising first and second tightening lugs suitable for being moved relative to each other in order to bring the ring into the tightened state, the first and second tightening lugs being secured to the sealing ring, respectively in the vicinity of the first free end of said ring and in the vicinity of the second free end of said ring, so that the first and second tightening lugs are respectively located at the first sealing arrangement and at the second sealing arrangement and the device having a bridge covering the sealing arrangements between said first and second tightening lugs, the bridge being mounted to be stationary relative to the first free end of the ring and suitable for sliding relative to the second free end while the ring is being tightened;

wherein the first and second sealing arrangements respectively comprise at least one tongue and at least one notch, tightening the ring causing the tongue to penetrate into the notch and causing the contact zones between the tongue and the notch to deform.

2. A device according to claim 1 , wherein the lugs and the ring are formed from strips of metal, the strip from which the ring is formed has a thickness (e) lying in the range 30% of the thickness of the strips from which the lugs are formed to 80% of said thickness of the strips from which the lugs are formed.

3. A device according to claim 1 , wherein the lugs and the ring are formed from strips of metal, the strip from which the ring is formed has a thickness lying in the range 40% of the thickness of the strips from which the lugs are formed to 60% of said thickness of the strips from which the lugs are formed.

4. A device according to claim 1 , wherein the ring is made from a strip of metal and the bridge is also made from a strip of metal, of thickness substantially equal to the thickness of the strip from which the ring is made.

5. A device according to claim 1 , wherein the lugs are formed from strip portions which have stamped-out portions or ribs that are designed to reinforce the rigidity of said strip portions.

6. A device according to claim 1 , wherein at least one of the tightening lugs is formed from a strip portion, and firstly has a tightening wall that is formed by a turned-out segment of said strip portion, which turned-out segment is configured to retain tightening means, and secondly has a loop having an end that is folded back between said strip portion and the ring.

7. A device according to claim 6 , wherein the folded-back end of the loop is received in a setback in the strip portion, said setback having a depth substantially equal to a thickness of the said folded-back end.

8. A device according to claim 6 , wherein one of the inside face of the strip portion and the outside face of the end of the loop has at least one bearing projection that co-operates with the other one of said inside face of the band strip and the outside face of the end of the loop.

9. A device according to claim 6 , wherein:

the folded-back end of the loop is received in a setback in the strip portion, said setback having a depth substantially equal to a thickness of the said folded-back end, and

one of the inside face of the strip portion and the outside face of the end of the loop has at least one bearing projection that co-operates with the other one of said inside face of the band strip and the outside face of the end of the loop.

10. A device according to claim 1 , wherein the sliding of the bridge is guided relative to the second free end of the ring.

11. A device according to claim 10 , wherein, in the vicinity of the second free end, the edges of the ring are provided with tabs that co-operate with the edges of the bridge.

12. A device according to claim 1 , having at least one pair of first tightening lugs and one pair of second tightening lugs situated facing each other, the second lugs being formed in two strip portions that are fastened to the ring with a gap between said two strip portions, and the bridge having a guide tab that extends in said gap.

13. A device according to claim 1 , having at least one pair of first tightening lugs and at least one pair of second tightening lugs situated facing each other, and two nut-and-bolt assemblies that co-operate with said pairs of first and second lugs, and longitudinal movement of one of the nut-and-bolt assemblies while the other nut-and-bolt assembly is being tightened being limited.

14. A device according to claim 1 , having at least one pair of first tightening lugs and at least one pair of second tightening lugs situated facing each other, and two nut-and-bolt assemblies that co-operate with said pairs of first and second lugs being designed to be retained by the lugs of one of the pairs, said lugs being formed from two strip portions fastened to the ring with a gap between said strip portions, and the bridge having a retaining tab that is turned out in said gap and with which at least one of the nuts is suitable to come into abutment on the side remote from the lugs.

15. A clamping device for coupling together in leaktight manner two smooth tubes that are disposed end-to-end, the device comprising: a sealing ring that is suitable for clamping around the facing ends of the two tubes, and that has a first free end provided with a first sealing arrangement and a second free end provided with a second sealing arrangement, the first and second sealing arrangements being designed to procure leaktight contact between said free ends when the ring is in a tightened state, the device further comprising first and second tightening lugs suitable for being moved relative to each other in order to bring the ring into the tightened state, the first and second tightening lugs being secured to the sealing ring, respectively in the vicinity of the first free end of said ring and in the vicinity of the second free end of said ring, so that the first and second tightening lugs are respectively located at the first sealing arrangement and at the second sealing arrangement and the device having a bridge covering the sealing arrangements between said first and second tightening lugs, the bridge being mounted to be stationary relative to the first free end of the ring and suitable for sliding relative to the second free end while the ring is being tightened;

wherein the lugs are formed from strip portions that are fastened to the ring, each of which strip portions covers said ring over an angular sector lying in the range 10° to 50°.

16. A device according to claim 15 , wherein the first and second sealing arrangements respectively comprise at least one tongue and at least one notch, tightening the ring causing the tongue to penetrate into the notch and causing the contact zones between the tongue and the notch to deform.

17. A device according to claim 15 , wherein the lugs are formed from strip portions that are fastened to the ring, each of which strip portions covers said ring over an angular sector lying in the range 25° to 35°.

18. A device according to claim 15 , wherein the lugs are formed from strip portions which have stamped-out portions or ribs that are designed to reinforce the rigidity of said strip portions.

19. A device according to claim 15 , wherein at least one of the tightening lugs is formed from a strip portion, and firstly has a tightening wall that is formed by a turned-out segment of said strip portion, which turned-out segment is configured to retain tightening means, and secondly has a loop having an end that is folded back between said strip portion and the ring.

20. A clamping device for coupling together in leaktight manner two smooth tubes that are disposed end-to-end, the device comprising: a sealing ring that is suitable for clamping around the facing ends of the two tubes, and that has a first free end provided with a first sealing arrangement and a second free end provided with a second sealing arrangement, the first and second sealing arrangements being designed to procure leaktight contact between said free ends when the ring is in a tightened state, the device further comprising first and second tightening lugs suitable for being moved relative to each other in order to bring the ring into the tightened state, the first and second tightening lugs being secured to the sealing ring, respectively in the vicinity of the first free end of said ring and in the vicinity of the second free end of said ring, so that the first and second tightening lugs are respectively located at the first sealing arrangement and at the second sealing arrangement and the device having a bridge covering the sealing arrangements between said first and second tightening lugs, the bridge being mounted to be stationary relative to the first free end of the ring and suitable for sliding relative to the second free end while the ring is being tightened;

wherein the lugs are formed from strip portions which are fastened to the ring in zones of the ring that form indents in the inside face of the ring.