Fusible link comprising damper and backstop

1. A link comprising:

a rod having a connection member at each end with an axis going through both connection members, wherein said rod includes a fusible zone in a form of a narrow section lying between a first rod portion connected to a first of the connection members and a second rod portion connected to a second of the connection members, said fusible zone configured to break when tensile force to which said link is subjected is greater than a predetermined value;

a body coaxial about said axis and secured at one end to the first rod portion, said body presenting at its other end an end wall having an orifice through which the second rod portion is capable of sliding, said body defining a cavity in which the fusible zone is housed, together with a collar formed around the second rod portion configured to slide into said cavity in an event of the fusible zone breaking;

a plurality of teeth formed on an inside wall of the body, said teeth being configured to be broken by the collar following breaking of the fusible zone; and

means for preventing return movement of the second rod portion after the fusible zone has broken,

wherein said plurality of teeth, while being broken by said collar, absorb a shock in the event of the fusible zone breaking, and

wherein said plurality of teeth are formed on the inside wall of the body in an annular chamber defined by the collar and by the end wall of the cylinder body.

2. A link according to claim 1 , wherein said body is configured so that the two rod portions are inseparable after the fusible zone breaks.

3. A link according to claim 2 , wherein said teeth are spread over one or more spirals.

4. A link according to claim 1 , wherein said means for preventing return movement comprises at least a first tooth different from said plurality of teeth and formed on the inside wall of the cylinder body and facing a helical groove made in a periphery of the collar, co-operation between said first tooth and said groove immediately after the fusible zone has broken causing at least one of the rod portions to become twisted, said first tooth forming an anti-return abutment after the collar has moved past it as a consequence of said rod portion turning in an opposite direction by elastic effect.

5. A link according to claim 1 , wherein said teeth are spread over one or more spirals.

6. A link according to claim 4 , wherein said teeth are spread over one or more spirals.

7. A link according to claim 1 , wherein said body and said cavity are cylindrical.

8. A link comprising:

a rod having a connection member at each end with an axis going through both connection members, wherein said rod includes a fusible zone in a form of a narrow section lying between a first rod portion connected to a first of the connection members and a second rod portion connected to a second of the connection members, said fusible zone configured to break when tensile force to which said link is subjected is greater than a predetermined value;

a body coaxial about said axis and secured at one end to the first rod portion, said body presenting at its other end an end wall having an orifice through which the second rod portion is capable of sliding, said body defining a cavity in which the fusible zone is housed, together with a collar formed around the second rod portion configured to slide into said cavity in an event of the fusible zone breaking;

a plurality of teeth formed on an inside wall of the body, said teeth being configured to be broken by the collar following breaking of the fusible zone,

wherein said collar defines a groove.

9. A link according to claim 8 , further comprising a first tooth, different from said plurality of teeth, formed on the inside wall of the body and configured to engage said groove after the fusible zone breaks.

10. A link according to claim 9 , wherein said groove is helical.

11. A link according to claim 9 , wherein said groove traverses said collar so that said first tooth enters said groove at one side of said collar and exits said collar at another side of said collar as said collar slides into said cavity after the fusible zone breaks.

12. A link according to claim 11 , wherein said first tooth abuts against said collar after said first tooth exits said collar.

13. A link according to claim 12 , further comprising a second tooth, different from said plurality of teeth, formed on the inside wall of the body and configured to engage said groove after said first tooth exits said collar.

14. A link according to claim 9 , wherein said first tooth is located relative to said plurality of teeth so that said first tooth engages said groove of said collar before said collar breaks said plurality of teeth following breaking of the fusible zone.