Pipe couplings

Claim 2

In a pipe coupling having a female coupling element of the kind having an internal bore to receive a male element, and a locking member displaceable transversely to the bore against resilient return means, the locking member having a keyhole shaped opening through it in the direction of the bore, the narrow part of this opening normally being held in the bore by the return means and displacement of the locking member bringing the wider part of the keyhole shaped opening into alignment with the bore, so that a male element with a shoulder proximate its free end can be inserted into the bore, the shoulder passing through the wider part of the opening, subsequent return of the locking member by the return means bringing the narrower part of the opening around the male element on the opposite side of the shoulder to the free end to prevent uncoupling, the improvement in the female coupling element which comprises doubly oblique opposed side surfaces at each side of the narrower part of the opening, such that on insertion into the bore of a male element whose shoulder has a frustoconical leading surface, the action of said leading surface bearing on said doubly oblique side surfaces automatically displaces said locking member to allow said shoulder to pass through it.

Claim 3

Coupling according to claim 1 in which said doubly oblique side surfaces have the shape of a funnel.

Claim 4

Coupling according to claim 1 wherein the female coupling element further comprises a guide member for said male element during insertion into said female element, said guide member being positioned to prevent radial displacement of said male element by reaction to said leading surface bearing on said doubly oblique side surfaces.

Claim 5

Coupling according to claim 3 wherein the female coupling element has an internal ring, and said guide member is integral with said ring.

Claim 6

Coupling according to claim 4 wherein said return means is a leaf spring, having a pair of ends, and wherein said internal ring has a pair of abutments integral with and extending from it, and said ends of said leaf spring bear against said abutments.

Claim 7

An automatic pipe coupling for the non-permanent joining of two pipes, the coupling having a female element terminating one pipe to be joined and a male element terminating the other pipe to be joined, the male element comprising: a cylindrical end portion terminating at a free end, and an annular shoulder on said cylindrical end portion proximate said free end but spaced from it, said shoulder having a maximum diameter, and leading and trailing surfaces extending between said maximum diameter and said cyindrical end portion and either side of said maximum diameter, said leading surface extending from said maximum diameter towards at least said leading surface being of frustoconical form; the female element comprising: a cylindrical part terminating at a free end, an open mouth at said free end of said cylindrical part, a generally cylindrical bore extending inwardly into said cylindrical part from said mouth to receive the end portion of the male element, a locking member mounted in said cylindrical part, and extending transversely across said bore, and having a front face facing said mouth, a rear face on the side opposed to said front face, and an opening through it in the direction of said bore, said opening being of keyhole shaped outline with a wider part and a narrower part the wider part being part-circular and of diameter slightly greater than that of said maximum diameter of said shoulder on the male element, the narrower part being of width less than said maximum diameter of said shoulder, but greater than the diameter of said cylindrical end portion, and having opposed side edges, said edges having doubly oblique surfaces extending inwardly from said first face, resilient return means, said locking member being displaceable transversely to said bore against said return means, and an access opening in said cylindrical part, through which access may be gained to said locking member, for manual displacement thereof against said return means the return means normally maintaining the locking member in alignment with the narrower part of the opening in the bore, but displacement of the locking member bringing the wider part into line with the bore, on insertion of the male element into the female, the leading frustoconical surface of the shoulder bearing on said doubly oblique surfaces and thereby automatically displacing the locking member to bring the wider part into line with the bore and permit said maximum diameter of said shoulder to pass through the locking member, whereupon the return means returns the locking member and removal of the male element is prevented by said shoulder abutting said rear face of the locking member.

Claim 8

An automatic pipe coupling for the non-permanent joining of two pipes, the coupling having a female element terminating one pipe to be joined and a male element terminating the other pipe to be joined, the male element comprising: a cylindrical end portion terminating at a free end, and an annular shoulder on said cylindrical end portion proximate said free end but spaced from it, said shoulder having a maximum diameter, and leading and trailing surfaces extending between said maximum diameter and said cyindrical end portion and either side of said maximum diameter, said leading surface extending from said maximum diameter towards at least said leading surface being of frustoconical form; the female element comprising: a cylindrical part terminating at a free end, an open mouth at said free end of said cylindrical part, a generally cylindrical bore extending inwardly into said cylindrical part from said mouth to receive the end portion of the male element, a locking member mounted in said cylindrical part, and extending transversely across said bore, and having a front face facing said mouth, a rear face on the side opposed to said front face, and an opening through it in the direction of said bore, said opening being of keyhole shaped outline with a wider part and a narrower part the wider part being part-circular and of diameter slightly greater than that of said maximum diameter of said shoulder on the male element, the narrower part being of width less than said maximum diameter of said shoulder, but greater than the diameter of said cylindrical end portion, and having opposed side edges, said edges having doubly oblique surfaces extending inwardly from said first face, resilient return means, said locking member being displaceable transversely to said bore against said return means, and an access opening in said cylindrical part, through which access may be gained to said locking member, for manual displacement thereof against said return means the return means normally maintaining the locking member in alignment with the narrower part of the opening in the bore, but displacement of the locking member bringing the wider part into line with the bore, on insertion of the male element into the female, the leading frustoconical surface of the shoulder bearing on said doubly oblique surfaces and thereby automatically displacing the locking member to bring the wider part into line with the bore and permit said maximum diameter of said shoulder to pass through the locking member, whereupon the return means returns the locking member and removal of the male element is prevented by said shoulder abutting said rear face of the locking member.

Claim 9

Coupling according to claim 6 in which said doubly oblique side surfaces have the shape of a funnel.

Claim 10

Coupling according to claim 7 wherein said cylindrical part of said female element contains an internal ring, said ring having a guide member and a pair of abutments integral with and extending from it, said guide member guiding the male element during insertion thereof and being positioned to block radial displacement of it by reaction to said leading surface bearing on said doubly oblique side surfaces, said resilient return means being a leaf spring having a pair of ends, said ends bearing on said abutments, and wherein said generally cylindrical bore contains a sealing ring for sealing said bore to the male element in fluid tight manner.

Claim 11

Coupling according to claim 6 wherein said trailing surface of said shoulder on said male element is frustoconical and extends from said maximum diameter away from said free end of said cylindrical portion, and wherein said rear face of said locking member, at each side of said narrower part of said keyhole shaped opening therein, has facets which are part of a frustoconical surface, and which assist in aligning said wider part of said opening with said bore in said female element on removal of said male element therefrom.