We Claim:
1. A foldable article, in particular of the tent or shelter type, the article having a deployed position for use and comprising a hoop structure (1,2) that is foldable into a circular configuration and that comprises at least a base loop (1) and an upper loop (2) non-plane when the article is in the deployed position, a flexible sheet (3, 4) secured to the hoop structure (1, 2), and folding-assistance means (5, and 6 to 10); the article being characterized in that the folding-assistance means (5, and 6 to 10) comprise at least one pull element (5) connected to a first source point (5a) of one of said at least two loops (1,2) or of the flexible sheet (3,4) along said loop (1,2) and suitable, when traction is applied to the pull element (5), for enabling the first source point (5a) to be brought towards a first target point (6 to 10) of said loop (1,2) or of the flexible sheet (3, 4) along said loop (1,2), the pull element (5) being also connected to a second source point (13, 17, 21) of the other of said loops (1, 2) or of the flexible sheet (3,4) along said other of said loops, and suitable, when traction is applied to the pull element (5), for enabling the second source point to be brought towards the first target point (6 to 10), the first target point (6 to 10) and the first source point (5a) satisfying the following accumulative conditions:
a) the distance measured along said loop (1,2) between the first source point (5a) and the first target point (6 to 10) is greater than or equal to 2nRrupt, where Rrupt is the limit radius of curvature of said loop (1,2);
b) when the loop (1,2) presents a shape that is substantially non-plane when the article is in the deployed position, with at least one main major axis (Al, A2) and at least one main minor axis (al, a2), the {first source point (5a); first target point (6 to 10)} pair lies neither on the main major axis (Al, A2) nor on the main minor axis (al, a2); and
c) when said loop (1,2) presents a shape that is substantially plane and oblong when the article is in the deployed position, with at least one main major axis (Al, A2), the {first source point (5a); first target point (6 to 10)} pair does not lie on the main major axis (Al, A2);
thereby enabling at least two sub-loops (la, lb, 1c) to be formed by twisting each of said two loops (1, 2).

2. The article as claimed in claim 1, wherein the pull means (5) are secured to the flexible sheet (3, 4) by stitching either directly or via stitching to an intermediate textile part such as a sheath in which said loop (1, 2) is inserted.
3. The article as claimed in claim 1 or claim 2, wherein the folding-assistance means (5, and 6 to 10) include a marker (6 to 10) arranged at the first target point (6 to 10).
4. The article as claimed in any one of claims 1 to 3, wherein the pull element (5) is secured to a second source point (5b) of said loop (1,2) or of the flexible sheet (3, 4) along said loop (1,2), the pull element (5) being suitable for enabling the second source point (5b) to be brought towards a second target point (6 to 10) of said loop (1,2) or of the flexible sheet (3, 4) along said loop (1, 2) by applying traction to the pull element (5).
5. The article as claimed in claim 4, wherein the first and second target points (6 to 10) coincide.
6. The article as claimed in any one of claims 1 to 5, wherein the pull means (5) are an elongate flexible element (5), e.g. of the cord, strap, or flexible handle type, that is fastened at a first end to the first source point (5a).
7. The article as claimed in claim 6, wherein the first end of the elongate flexible element (5) is fastened to the first source point (5a) inside said article.
8. The article as claimed in claim 6 or claim 7, wherein the folding-assistance means (5, and 6 to 10) include a first guide element (11), e.g. of the rigid ring or textile ring type, suitable for enabling a second end of the elongate flexible element (5) to pass therethrough and located at the first target point (6 to 10).
9. The article as claimed in claim 4 or claim 5, wherein the pull means (5) are an

elongate flexible element (5), e.g. of the cord, strap, or flexible handle type, that is fastened at a first end to the first source point (5a) and at a second end to the second source point (5b).
10. The article as claimed in claim 9, wherein the elongate element (5) forms one or more loops (12) between its first and second ends, and wherein the folding-assistance means (5, and 6 to 10) include first and second guide elements (11), e.g. of the rigid ring or textile ring type, suitable for enabling said loop(s) (12) to pass therethrough and located respectively at the first and second target points (6 to 10).
11. The article as claimed in any one of claims 1 to 10, wherein said loop (1, 2) is a base loop (1), wherein the flexible sheet (3, 4) includes an opening, and wherein the first source point (5a) is located inside said article opposite from said opening and on said base loop (1).
12. The article as claimed in any one of claims 1 to 10, wherein said loop (1, 2) is an upper loop (2), and wherein the first source point (5a) is arranged outside said article and at said upper loop (2).
13. The article as claimed in any of claims 1 to 12, wherein the pull element (5), said loop (1,2), and the flexible sheet (3, 4) are such that the pull element (5) can be secured in temporary or permanent manner to said loop (1,2) or to the flexible sheet (3, 4) along said loop (1, 2) at a succession of points (5a, and 6 to 10) constituting successive source points for the respective following points in said succession of points (5a, and 6 to 10) and target points for the respective preceding points in said succession of points (5a, and 6 to 10), the pull element (5) being suitable for enabling a source point of said succession of points (5a and 6 to 10) to be brought successively or simultaneously up to a corresponding target point by pulling one or more times on the pull element (5) so as to enable one or more sub-loops to be formed, possibly in the form of superposed turns, as a result of successive twists of said loop (1, 2).

14. A method of folding an article, in particular of the tent or shelter type, the article having a deployed position for use and comprising a hoop structure (1,2) foldable into a circular configuration and comprising at least a base loop (1) and an upper loop (2) non-plane when the article is in the deployed position, a flexible sheet (3, 4) secured to the hoop structure (1, 2), and folding-assistance means (5, and 6 to 10), the folding-assistance means (5, and 6 to 10) including a pull element (5) secured to a first source point (5a) of one of said at least two loops (1, 2) or of the flexible sheet (3, 4) along said loop (1,2), and to a second source point (13,17,21) of the other of said loops (1,2) or of the flexible sheet (3,4) along said other of said loops, said method consisting in particular in forming at least two sub-loops (la, lb, lc) from each of said two loops (1, 2);
the method being characterized in that in order to form said two sub-loops (la, lb, lc), traction is exerted on the pull element (5) to bring the first source point (5a) and the second source point (13,17, 21) towards a first target point (6 to 10) of said loop (1, 2) or of the flexible sheet (3, 4) along said loop (1, 2), the first target point (6 to 10) and the first source point (5a) satisfying the following accumulative conditions:
a) the distance measured along said loop (1,2) between the first source point (5a) and the first target point (6 to 10) is greater than or equal to 27tRrupt, where Rrupt is the limit radius of curvature of said loop (1,2);
b) when the loop (1,2) presents a shape that is substantially non-plane, when the article is in the deployed position with at least one main major axis (Al, A2) and at least one main minor axis (al, a2), the (first source point (5a); first target point (6 to 9)} pair lies neither on the main major axis (Al, A2) nor on the main minor axis (al, a2); and
c) when said loop (1, 2) presents a shape that is substantially plane and oblong, when the article is in the deployed position with at least one main major axis (Al, A2), the {first source point (5a); first target point (6 to 10)} pair does not lie on the main major axis (Al, A2) ;
thereby enabling said two sub-loops (la, lb, lc) to be formed by twisting each of said two loops (1,2).