Tape spring retractable deployable structure and method

1. A retractable tape spring in-building method for a deployable structure, comprising a main tape spring extending in a deployed position along an axis X and comprising two ends, a secondary tape spring comprising two ends and a winding mandrel carried by a shaft along an axis Z perpendicular to the axis X, the main tape spring being wound around the mandrel, a first end of the main tape spring being fixed to the mandrel,

the method comprising the following steps:

fixing a first end of the secondary tape spring to the main tape spring spaced from the first end of the main tape spring,

fixing a second end of the secondary tape spring to the mandrel at a point distinct from the first end of the main tape spring.

2. The retractable in-building method according to claim 1 , further comprising the following steps:

simultaneous deployment of the main tape spring substantially parallel to the axis X and of the secondary tape spring,

formation of a triangulated structure between the main tape spring, the secondary tape spring and the mandrel.

3. The retractable in-building method according to claim 1 , further comprising a step of rewinding the main tape spring, and the rewinding of the main tape spring is obtained by buckling the secondary tape spring.

4. The retractable in-building method according to claim 3 , the main tape spring comprising two faces, wherein the first end of the secondary tape spring is fixed to a first face of the second end of the main tape spring, and wherein the buckling of the secondary tape spring is obtained by applying a force to the middle of the secondary tape spring and normal to the secondary tape spring.

5. The retractable in-building method according to claim 3 , wherein the force is applied between the first end of the secondary tape spring and the second end of the main tape spring.

6. The retractable in-building method according to claim 1 , further comprising a step of fixing the first end of the main tape spring to a middle of the mandrel.

7. The retractable in-building method according to claim 6 , the deployable structure comprising at least two rollers mounted facing each other and mounted at a periphery of the mandrel, the rollers being in contact with the main tape spring, and the rollers and the shaft having a degree of freedom to rotate about the axis Z relative to one another, further comprising the following steps:

local guidance of the main tape spring by the rollers,

deployment of the main tape spring in a direction substantially parallel to the axis X.

8. The retractable in-building method according to claim 7 , the rollers being heating rollers, comprising beforehand a step of local heating of the main tape spring by the heating rollers.

9. A deployable structure comprising a main tape spring extending in a deployed position along an axis X and comprising two ends, a secondary tape spring comprising two ends and a winding mandrel carried by a shaft along an axis Z perpendicular to the axis X, the main tape spring being wound around the mandrel, a first end of the main tape spring being fixed to the mandrel, wherein a first end of the secondary tape spring is fixed to the main tape spring spaced from the first end of the main tape spring, and a second end of the secondary tape spring is fixed to the mandrel at a point distinct from the first end of the main tape spring.

10. The deployable structure according to claim 9 , further comprising at least two rollers mounted facing each other and mounted at a periphery of the mandrel, wherein the rollers are in contact with the main tape spring, and the rollers and the shaft are fixed, the mandrel having a degree of freedom to rotate about the axis Z, the rollers being able to guide the main tape spring.

11. The deployable structure according to claim 10 , wherein the rollers are heating rollers.