Couplings for tubes

Claim 2

A tube coupling having a collet 13 or 53 with resilient arms 16 or 56 arranged to co-operate with a cam surface on a body member 10 or 50 surrounding the collet, which body member has an internal surface 21 or 60 tapering to a smaller diameter in an axial direction and engaging the arms of the collet so that the collet arms are forced inwardly by axial movement of the collet 13 or 53 in said one direction; and a resilient annular member 29 or 43 or 69 in said body for sealing around a tube 12 or 52 inserted in the coupling characterised by the provision of means 30 or 71 for compressing said annular resilient element 29 or 43 or 69 axially so as to deform it radially inwardly.

Claim 3

A tube coupling as claimed in claim 1 and having a tube 12 inserted through said collet 13 or 53 and said resilient member 29 or 43 or 69, characterised in that the resilient member has an internal diameter such that the axial compression deforms it inwardly into tight engagement with the outer surface of the tube 12.

Claim 4

A tube coupling having a collet 13 or 53 with resilient arms 16 or 56 arranged to co-operate with a cam surface 21 on a body member 10 surrounding the collet, which body member 10 has an internal surface 21 tapering to a smaller diameter in one axial direction and engaging the arms 16 of the collet 13 so that the collet arms are forced inwardly by axial movement of the collet in said one direction, and in which an annular resilient member 29 or 43 is provided between the collet 13 and an internal shoulder 28 or 48 on a support 10 or 42 or 50 for the annular resilient member 29 or 43 characterised in that an annular element 30 is provided in the coupling between the annular resilient member 29 or 43 and the collet 13, which annular element 30 or 70 is adjustably secured in said support so that it can be positioned to hold the annular resilient member 29 or 43 in compression against said shoulder 28 or 48.

Claim 5

A tube coupling having a collet 13 or 53 with resilient arms 16 or 56 arranged to co-operate with a cam surface 21 on a body member 10 surrounding the collet, which body member 10 has an internal surface 21 tapering to a smaller diameter in one axial direction and engaging the arms 16 of the collet 13 so that the collet arms are forced inwardly by axial movement of the collet in said one direction, and in which an annular resilient member 29 or 43 is provided between the collet 13 and an internal shoulder 28 or 48 on a support 10 or 42 or 50 for the annular resilient member 29 or 43 characterised in that an annular element 30 is provided in the coupling between the annular resilient member 29 or 43 and the collet 13, which annular element 30 or 70 is adjustably secured in said support so that it can be positioned to hold the annular resilient member 29 or 43 in compression against said shoulder 28 or 48.

Claim 6

A tube coupling as claimed in claim 3 characterised in that said annular element 30 is a threaded element engaging an internal thread 32 in said support 10 or 42 or 50.

Claim 7

A tube coupling as claimed in claim 3 characterised in that the collet 13 and annular element 30 are provided with mutually-engaging portions 17, 18, 35, 36 such that the annular element 30 can be rotated in said support 10 or 42 or 50 by rotation of the collet 13.

Claim 8

A tube coupling as claimed in claim 5 characterised in that the annular element 30 has a castellated end and the collet arms 17, 18 are formed to engage in the castellations.

Claim 9

A tube coupling as claimed in claim 5 characterised in that alternate arms 17, 18 of the collet are of different length and the castellations 35, 36 comprise recesses for receiving the longer collet arms.

Claim 10

A tube coupling as claimed in any of claims 3 to 7 characterised in that said support 10 or 42 or 50 comprises a part of said body member.

Claim 11

A tube coupling as claimed in any of claims 3 to 8 characterised in that the annular element 30 has an external thread 31 engaging an internal thread 32 in a cylindrical portion of said member 10 or 42 or 50 constituting said support.

Claim 12

A tube coupling as claimed in any of claims 3 to 7 characterised in that said support is a holder 42 for the annular resilient member 43 and positioned within said body member and wherein the annular element 30 is threaded in said support 42 for adjustment in the axial direction to enable the annular resilient member 43 to be compressed between the annular element 3 0 and a shoulder 48 in the support, and in that a further seal 46 is provided between the support 42 and said body member 10.

Claim 13

A tube coupling as claimed in claim 10 characterised in that the further seal 46 is a further annular resilient member around said support.

Claim 14

A tube coupling as claimed in either claim 10 or claim 11, characterised in that said support 42 is axially movable in said body member 10 between a shoulder therein and said collet but is locked against rotation therein.

Claim 15

A tube coupling for holding a tube 12 of predetermined external diameter comprising a body member 10 having an internal bore 11, a collet 13 fitting in said bore from one end thereof and an O-ring 29 or 43 or 69 around said tube 12 adjacent a shoulder 28 or 49 on the body member 10 or on a support 42 in the body member, which shoulder 28 or 49 faces the end of the bore 11 from which, the collet 13 is inserted, the bore 11 in said body member 10, between the shoulder 28 or 49 and the end from which the collet 13 is inserted having a tapered portion 21 tapering from a larger diameter portion down to a smaller diameter portion and the collet 13 having resilient arms 17, 18 with surface portions 20 engaging the tapered surface 21 on said body member 10 so that the collet arms are forced radially inwardly to grip the tube as the collet is moved towards said end and characterised in that an annular element 30 is provided adjustable for movement to compress the O-ring 29 or 43 against said shoulder so as thereby to cause the O-ring to seal tightly around said tube.

Claim 16

A tube coupling for holding a tube 12 of predetermined external diameter comprising a body member 10 having an internal bore 11, a collet 13 fitting in said bore from one end thereof and an O-ring 29 or 43 or 69 around said tube 12 adjacent a shoulder 28 or 49 on the body member 10 or on a support 42 in the body member, which shoulder 28 or 49 faces the end of the bore 11 from which, the collet 13 is inserted, the bore 11 in said body member 10, between the shoulder 28 or 49 and the end from which the collet 13 is inserted having a tapered portion 21 tapering from a larger diameter portion down to a smaller diameter portion and the collet 13 having resilient arms 17, 18 with surface portions 20 engaging the tapered surface 21 on said body member 10 so that the collet arms are forced radially inwardly to grip the tube as the collet is moved towards said end and characterised in that an annular element 30 is provided adjustable for movement to compress the O-ring 29 or 43 against said shoulder so as thereby to cause the O-ring to seal tightly around said tube.

Claim 17

A tube coupling as claimed in claim 13 characterised in that said shoulder 28 is formed in said body member 10 and in that the annular element 30 has an external thread 31 engaging an internal thread 32 on the body member 10.

Claim 18

A tube coupling as claimed in claim 13 characterised in that said shoulder 4,9 is formed on a support 42 which is axially movable in said body member 10 but is locked against rotation therein and in that the annular element 30 has an external thread 31 engaging an internal thread 40 in said support 42.

Claim 19

A tube coupling as claimed in any of claims 13 to 15 characterised in that the collet 13 and the annular element 30 are provided with mutually-engaging portions 17, 18, 35, 36 such that the annular element 30 can be rotated by rotation of the collet 13.

Claim 20

A tube coupling having a collet 53 with resilient arms 56 arranged to co-operate with a cam surface 21 or 60 on a member surrounding the collet 53, which member has an internal surface tapering to a smaller diameter in one axial direction and engaging the arms 56 of the collet 53 so that the collet arms 56 are forced inwardly by axial movement of the collet in said one direction, and in which a resilient annular member 69 is provided in said member between the collet and an internal shoulder 68 in said member, characterised in that spring means 70 are provided in the coupling between the collet 53 and the resilient annular member 69 operative when the collet 53 is in said member to press the. resilient annular member 69 away from the collet 53 in an axial direction against a shoulder 68 in said member.

Claim 21

A tube coupling having a collet 53 with resilient arms 56 arranged to co-operate with a cam surface 21 or 60 on a member surrounding the collet 53, which member has an internal surface tapering to a smaller diameter in one axial direction and engaging the arms 56 of the collet 53 so that the collet arms 56 are forced inwardly by axial movement of the collet in said one direction, and in which a resilient annular member 69 is provided in said member between the collet and an internal shoulder 68 in said member, characterised in that spring means 70 are provided in the coupling between the collet 53 and the resilient annular member 69 operative when the collet 53 is in said member to press the. resilient annular member 69 away from the collet 53 in an axial direction against a shoulder 68 in said member.

Claim 22

A tube coupling for holding a tube 52 of predetermined external diameter comprising an outer member 50 having an internal bore, a collet 53 fitting in said bore from one end thereof and a resilient annular member 69 forming a seal seated within said bore against a shoulder 68 therein, which shoulder 68 faces the end from which the collet 53 is inserted, the bore in said member, between the shoulder 68 and the end from which the collet is inserted having a tapered portion 60 tapering from a larger diameter portion down to a smaller diameter portion, and the collet 53 having resilient arms 56 with surface portions engaging the tapered surface 60 on said member 50 so that the collet arms are forced radially inwardly as the collet is moved towards said end, and characterised in that spring means 70 are provided in said bore operative to force the resilient annular member 69 away from the ends of the collet arms 16.towards said shoulder 68.

Claim 23

A tube coupling for holding a tube 52 of predetermined external diameter comprising an outer member 50 having an internal bore, a collet 53 fitting in said bore from one end thereof and a resilient annular member 69 forming a seal seated within said bore against a shoulder 68 therein, which shoulder 68 faces the end from which the collet 53 is inserted, the bore in said member, between the shoulder 68 and the end from which the collet is inserted having a tapered portion 60 tapering from a larger diameter portion down to a smaller diameter portion, and the collet 53 having resilient arms 56 with surface portions engaging the tapered surface 60 on said member 50 so that the collet arms are forced radially inwardly as the collet is moved towards said end, and characterised in that spring means 70 are provided in said bore operative to force the resilient annular member 69 away from the ends of the collet arms 16.towards said shoulder 68.

Claim 24

A tube coupling as claimed in either claim 17 or claim 18 characterised in that the collet 53, spring means 70 and said member 50 are dimensioned so that, when the collet 53 is inserted in said member 50, said spring means 70 are compressed and so apply axial compression onto the resilient annular member 69.

Claim 25

A tube coupling as claimed in claim 19 characterised in that said spring means comprise a spring washer 70 having an annular surface 71 extending continuously around the tube in a plane normal to the axis thereof, said surface being arranged to bear against the resilient annular member 69, and in that the spring washer further has resilient portions 72 extending from this surface to bear against the end surfaces of the collet arms 56.