Intra-uterine device

Claim 2

An intra-uterine contraceptive device comprising an elongate flexible member of a predetermined uniform cross-section disposed in a continuous coil wherein one side in each convolution confronts the opposite side in the adjacent convolution and wherein the one side contains spaced parallel grooves of a predetermined configuration having restricted openings in communication therewith at said side and the opposite side has spaced parallel ribs complementary in configuration to the grooves disposed through said restricted openings, said grooves being of larger cross-section than said ribs such that there are clearance spaces of uniform width between the interior surfaces of the grooves and the exterior surfaces of the ribs which permit the interengaged lengths thereof to move longitudinally relative to each other and hence to contract and expand with changes in the dimensions of the uterine cavity, said member being prestressed to take up a closed coiled configuration in which the external convolution is at least as great as the maximum dimension of the uterine cavity.

Claim 3

An intra-uterine contraceptive device adapted to be disposed in the uterine cavity comprising an elongate flexible member of a predetermined uniform cross-section disposed in a continuous coil of overlapping convolutions such that one side of each convolution confronts the opposite side of the adjacent convolution and wherein the one side contains a continuous groove of predetermined internal configuration having a restricted opening in communication therewith at said side, and the other side has a continuous rib complementary in configuration to the groove disposed through said constrictive opening, said rib being slightly larger in cross-section than said restricted opening and appreciably smaller in cross-section than said groove such that there is an appreciable clearance between the interior surface of the groove and the exterior surface of the rib throughout the interengaged lengths thereof which permits longitudinal movement of the rib within the groove in either direction, and said member being elastically stressed to maintain its contact with the walls of the uterine cavity within which it is confined with changes in the dimensions of the uterine cavity.

Claim 4

An intra-uterine contraceptive device adapted to be disposed in the uterine cavity comprising an elongate flexible member of a predetermined uniform cross-section disposed in a continuous coil of overlapping convolutions such that one side of each convolution confronts the opposite side of the adjacent convolution and wherein the one side contains a continuous groove of predetermined internal configuration having a restricted opening in communication therewith at said side, and the other side has a continuous rib complementary in configuration to the groove disposed through said constrictive opening, said rib being slightly larger in cross-section than said restricted opening and appreciably smaller in cross-section than said groove such that there is an appreciable clearance between the interior surface of the groove and the exterior surface of the rib throughout the interengaged lengths thereof which permits longitudinal movement of the rib within the groove in either direction, and said member being elastically stressed to maintain its contact with the walls of the uterine cavity within which it is confined with changes in the dimensions of the uterine cavity.

Claim 5

A device according to claim 2, wherein the convolutions are arranged in a spiral.

Claim 6

A device according to claim 2, wherein the convolutions are arranged in a helix.

Claim 7

A device according to claim 2, comprising inter-engageable means on the confronting sides of the device near the ends cooperable to prevent complete uncoiling of the flexible member.

Claim 8

A device according to claim 2, wherein there is a cord attached to the end of the external convolution operable to unwind the device when pulled.