GB1591103A - Tube connector - Google Patents

Description

(54) IMPROVED TUBE CONNECTOR (71) We, R. A. SMITH PLASTICS LIMITED of 3 Crossness Road, Barking, Essex and AGRON MANUFACTURING Co. LIMITED of Clements House, Sanderstead Station Approach, S. Croydon, Surrey, both British Companies, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be described in and by the following statement: This invention relates to a connector for joining together two tubes.

A connector is known for joining together two tubes to form a 'T' which consists of a head shaped to fit against one tube and a shank receivable in the end of the other tube. A conical nut fits into the shank and has screwed into it a screw which is passed through holes in the first tube and into the connector by way of an aperture in the head. When the screw is tightened, the nut is drawn into the shank and expands it against the inner surface of the other tube. Although widely used, this type of connector is not easy to assemble, and it must be used with a non-conventional type of nut.

Patent specification No. 1,232,489 discloses a connector adapted for use with a conventional hexagonal nut but which has not proved satisfactory in use.

The present invention seeks to provide a connector which is more easily assembled and which may be used with a conventional nut. Accordingly, the invention provides a plastics connector for use in joining together two tubes, comprising a head shaped to fit against one tube, a shank receivable in the end of the other tube, and an expansion member for expanding the shank, the shank and said member being interconnected, and the member receiving non-rotatably in a cavity pre-formed in the member a nut or other internally threaded element into which may be screwed a screw or bolt capable of being passsed through the head and shank, whereby tightening of the screw or bolt and the internally threaded element causes the member to be drawn into the shank to expand it, thereby breaking the connection.The member may be moulded in one piece with the shank, or bonded or welded to it, or otherwise held in place in relation to it in such a way that it does not become dislodged when it is penetrated by the screw or bolt.

According to another aspect of the invention there are provided, for assembling a connector, two plastics components each of which is so shaped that the components may be brought into face to face relationship to define a head, a shank and an expansion member jointed to the shank by a frangible connection; those portions of the two components which define the ex pansion member being formed with respective recesses so shaped as to form a cavity for receiv ing non-rotatably a nut when the components are brought into face to face relationship, and those portions of the components which define the head and shank being so shaped as to form a bore when the components are brought into face to face relationship, whereby screw or a bolt passed through the bore may threadingly engage a nut in the cavity and, upon being tightened, cause the frangible connection to be broken and the expansion member to be drawn into the shank. The two components may be hinged together at the end of the ex pansion member.In this way, a conventional nut may be inserted in the cavity formed by the co-operating recesses and the two com ponents brought together and inserted in the tube.

The invention will now be described in greater detail but by way of example only, with reference to the accompanying drawing in which; Figure 1 is an axial section showing the con nector in place when in use, Figure 2 is a perspective view of one com ponent of the connector, Figure 3 is an elevational view of the com ponent showing how it may be moulded in one piece with another identical component.

Referring to the drawings, two tubes A and B are connected to form a 'T'. A connector for this purpose is generally indicated at 1 and is moulded from plastics so as to have a shank 2 and a head 3. The outer diameter of the shank is such as to enable it to fit within the tube A, and the outer diameter of the head is such as to make the head flush with the tube. The end face of the head has a concave surface equal in radius to that of the outer surface of the tube B. At the centre of this end face is a hole 4 which opens to the interior of the shank. At its end remote from the head, the internal surface of the shank tapers towards the head.In order to expand the shank and cause it to grip the internal surface of the tube A, the connector is provided with an integral tapered expansion member 5 having an internal cavity for a hexagonal nut 6, into which is screwed a screw or bolt 7. The expansion member is joined to the shank by a frangible strip or joint 8. The cone angles of the expansion member and the tapering internal face of the shank are substantially equal.

Conveniently, the connector shown in Figure 1 and consisting of head, shank and expansion member is assembled from two identical components, one of which is shown in Figure 2, the two components being adapted to be brought together in face to face relationship. One edge of that portion of each component which forms the shank has a projection 9 located between two recesses 10. The other edge is formed with two projections 11 separated by a recess 12.

The projections and recesses are formed internally of the shank and do not penetrate to the outer surface. The two components may be hinged together by a pair of hinges arranged on the end surfaces of the portions which co-operate to form the expansion member, one on each side of the opening in that surface, the hinges being shown at 13 in Figure 3.

To fit the connector, the tube B is drilled and the screw 7 passed through the resulting holes. The two components of the connector are brought together, entrapping between them the nut 6. In this way, and particularly by virtue of the hinged connection 13, the expansion member and shank may be introduced into the end of tube A without any risk of the nut dropping out. The loss of the nut at this stage of the assembly operation was a particular problem with the known design of connector referred to above. The tube B may now be offered up to the concave end face of the connector and the screw passed through the central opening therein into the connector. When the screw has engaged the nut, the screw is tightened to draw the nut towards the head.The force which the nut applies to the expansion member causes the strip to be sheared off, allowing the expansion member to be drawn into the shank. The expansion member acts wedge-like, in co-operation with the tapered internal surfaces of the shank, to urge the two components of the connector apart and into gripping engagement with the internal surface of the tube A.

To enable the screw to penetrate into the cavity in which the nut is located and to pass through the nut, the expansion member has apertures 19 and 20 at its respective ends. The aperture 19, facing towards the head, has a frusto-conical mouth to compensate for any misalignment of the screw. To compensate for variations in the internal diameter of the tube A, the shank is provided with a triangular sectioned bead 21 which grips the tube wall if the tube is over-sized or which is removed during insertion of the connector if the latter is a tight fit.

Multi-sided nuts, other than hexagonal nuts, may be employed, the cavity within the expansion member being shaped accordingly. The cavity in the expansion member could, conceivably, open to the end face of that member, provided that the nut is securely held against dropping out. The end face of the head may have a different shape if it is to be applied to a noncircular tube, and could, within the scope of the invention, be planar.

WHAT WE CLAIM IS: 1. A plastics connector for use in joining together two tubes, comprising a head shaped to fit against one tube, a shank receivable in the end of the other tube, and an expansion member for expanding the shank, the shank and said member being interconnected, and the member receiving non-rotatably in a cavity preformed in the member a nut or other internally threaded element into which may be screwed a screw or bolt capable of being passed through the head and shank, whereby tightening of the screw or bolt and the internally threaded element causes the member to be drawn into the shank to expand it, thereby breaking the connection.

2. A connector as claimed in claim 1, wherein the shank and the expansion member are moulded integrally one with the other from plastics material, there being a frangible connection between them.

3. A connector as claimed in claim 2, wherein the head, shank and expansion member are divided longitudinally into two components.

4. For assembling a connector, two plastics components each of which is so shaped that the components may be brought into face to face relationship to define a head, a shank and an expansion member jointed to the shank by a frangible connection; those portions of the two components which define the expansion member being formed with recesses so shaped as to form a cavity for receiving non-rotatably a nut when the components are brought into face to face relationship, and those portions of the components which define the head and shank being so shaped as to form a bore when the components are brought into face to face relationship, whereby a screw or a bolt passed through the bore may threadingly engage a nut in the cavity and, upon being tightened, cause the frangible connection to be broken and the expansion member to be drawn into the shank.

5. The components as claimed in claim 4, wherein the components are hinged together at the expansion member end.

6. The invention claimed in any preceding claim, wherein an aperture permitting the screw or bolt to pass into the expansion member has a frustoconical mouth.

7. The invention claimed in any preceding

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (9)

**WARNING** start of CLMS field may overlap end of DESC **. which opens to the interior of the shank. At its end remote from the head, the internal surface of the shank tapers towards the head. In order to expand the shank and cause it to grip the internal surface of the tube A, the connector is provided with an integral tapered expansion member 5 having an internal cavity for a hexagonal nut 6, into which is screwed a screw or bolt 7. The expansion member is joined to the shank by a frangible strip or joint 8. The cone angles of the expansion member and the tapering internal face of the shank are substantially equal. Conveniently, the connector shown in Figure 1 and consisting of head, shank and expansion member is assembled from two identical components, one of which is shown in Figure 2, the two components being adapted to be brought together in face to face relationship. One edge of that portion of each component which forms the shank has a projection 9 located between two recesses 10. The other edge is formed with two projections 11 separated by a recess 12. The projections and recesses are formed internally of the shank and do not penetrate to the outer surface. The two components may be hinged together by a pair of hinges arranged on the end surfaces of the portions which co-operate to form the expansion member, one on each side of the opening in that surface, the hinges being shown at 13 in Figure 3. To fit the connector, the tube B is drilled and the screw 7 passed through the resulting holes. The two components of the connector are brought together, entrapping between them the nut 6. In this way, and particularly by virtue of the hinged connection 13, the expansion member and shank may be introduced into the end of tube A without any risk of the nut dropping out. The loss of the nut at this stage of the assembly operation was a particular problem with the known design of connector referred to above. The tube B may now be offered up to the concave end face of the connector and the screw passed through the central opening therein into the connector. When the screw has engaged the nut, the screw is tightened to draw the nut towards the head.The force which the nut applies to the expansion member causes the strip to be sheared off, allowing the expansion member to be drawn into the shank. The expansion member acts wedge-like, in co-operation with the tapered internal surfaces of the shank, to urge the two components of the connector apart and into gripping engagement with the internal surface of the tube A. To enable the screw to penetrate into the cavity in which the nut is located and to pass through the nut, the expansion member has apertures 19 and 20 at its respective ends. The aperture 19, facing towards the head, has a frusto-conical mouth to compensate for any misalignment of the screw. To compensate for variations in the internal diameter of the tube A, the shank is provided with a triangular sectioned bead 21 which grips the tube wall if the tube is over-sized or which is removed during insertion of the connector if the latter is a tight fit. Multi-sided nuts, other than hexagonal nuts, may be employed, the cavity within the expansion member being shaped accordingly. The cavity in the expansion member could, conceivably, open to the end face of that member, provided that the nut is securely held against dropping out. The end face of the head may have a different shape if it is to be applied to a noncircular tube, and could, within the scope of the invention, be planar. WHAT WE CLAIM IS:

1. A plastics connector for use in joining together two tubes, comprising a head shaped to fit against one tube, a shank receivable in the end of the other tube, and an expansion member for expanding the shank, the shank and said member being interconnected, and the member receiving non-rotatably in a cavity preformed in the member a nut or other internally threaded element into which may be screwed a screw or bolt capable of being passed through the head and shank, whereby tightening of the screw or bolt and the internally threaded element causes the member to be drawn into the shank to expand it, thereby breaking the connection.

2. A connector as claimed in claim 1, wherein the shank and the expansion member are moulded integrally one with the other from plastics material, there being a frangible connection between them.

3. A connector as claimed in claim 2, wherein the head, shank and expansion member are divided longitudinally into two components.

4. For assembling a connector, two plastics components each of which is so shaped that the components may be brought into face to face relationship to define a head, a shank and an expansion member jointed to the shank by a frangible connection; those portions of the two components which define the expansion member being formed with recesses so shaped as to form a cavity for receiving non-rotatably a nut when the components are brought into face to face relationship, and those portions of the components which define the head and shank being so shaped as to form a bore when the components are brought into face to face relationship, whereby a screw or a bolt passed through the bore may threadingly engage a nut in the cavity and, upon being tightened, cause the frangible connection to be broken and the expansion member to be drawn into the shank.

5. The components as claimed in claim 4, wherein the components are hinged together at the expansion member end.

6. The invention claimed in any preceding claim, wherein an aperture permitting the screw or bolt to pass into the expansion member has a frustoconical mouth.

7. The invention claimed in any preceding

claim, including a bead surrounding the shank.

8. The invention claimed in any preceding claim, in combination with a screw and nut.

9. A connector as claimed in claim 1 and substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.