Collar tightening structure

1. A one-piece collar made of flexible plastics material and intended to be worn by a person or a pet, said plastics material being capable of containing an active material, the collar comprising:

a tightening structure consisting of a buckle located substantially on the a proximal part of said collar, the buckle having a hollow interior that defines a tunnel delimited by a top on the upper part thereof and by a bottom on the lower part thereof, said tunnel being capable of receiving, longitudinally and by threading, a strap which forms a distal part of the collar, the strap including an inner face intended to be in contact with the bottom of the buckle and having a plurality of indentations, wherein:

a first projecting structure is formed longitudinally on the top of the buckle, the first projecting structure including two bulges each located at one of the ends of said projecting structure;

a second projecting structure is formed transversely to the center of the bottom of the buckle, such that the first and second projecting structures face one another without touching, and a space (y) between the first projecting structure and the bottom is capable of having the strap pass therethrough such that, when the strap is threaded inside the buckle, the first projecting structure abuts a top face of said strap so as to exert a local holding pressure thereon, and the second projecting structure engages with an indentation in an underside of said strap; and

a value of a ratio (x/y) is substantially proportional to that of a ratio of a notch thickness to a strap thickness according to the relationship 0.9 EC/EL<x/y<1.1 EC/EL, wherein the space between the first projecting structure and the bottom is symbolized by “y”, a space between the second projecting structure and the edge of one of said bulges is symbolized by “x”; “EL” represents the strap thickness and “EC” symbolizes the notch thickness, the value of which is equal to a difference between the thickness (EL) of the strap and a depth of one of said indentations.

2. The one-piece collar according to claim 1 , wherein said bulges straddle the indentation in the strap when the strap is threaded inside the buckle so as to clamp around said strap.

3. The one-piece collar according to claim 2 , wherein a central part of the first projecting structure is slightly set back from the two bulges.

4. The one-piece collar according to claim 1 , wherein the second projecting structure forms a tooth of which a lateral part located on the side opposite to an insertion direction of the strap is at least on a line with the bottom of the buckle or is slightly inclined toward the threading direction of the strap.

5. The one-piece collar according to claim 1 , wherein the second projecting structure forms a central tooth and wherein the bottom comprises, in addition to the central tooth, a proximal tooth on a proximal part of the buckle and a distal tooth on a distal part of the buckle.

6. The one-piece collar according to claim 5 , wherein the proximal tooth, central tooth and distal tooth are spaced from one another by a length corresponding to a spacing between said indentations such that each of the teeth engages with one of said indentations when the strap is threaded into the buckle.

7. The one-piece collar according to claim 1 , wherein each of said indentations in the strap has a cross section that is substantially in the shape of a parallelogram, antiparallelogram, triangle or a combination of these shapes.

8. The one-piece collar according to claim 1 , wherein the buckle has openings in each of its lateral faces, said openings delimiting a constriction structure for both the top and the bottom of the buckle, the top and the bottom of the buckle being interconnected by lugs.

9. The one-piece collar according to claim 1 , wherein a hardness of the flexible plastics material from which the collar is made is between 60 Shore A and 60 Shore D.

10. The one-piece collar according to claim 1 , wherein the collar contains an active material that has a biocidal, medicinal or cosmetic effect, said active material being suitable for achieving a treatment action selected from an insecticide action, insect repellant action, attractive action, antifungal action, soothing action, calming action, fragrant action, wellness action or a combination thereof.