Temporary closure devices and tube couplings incorporating such devices

The disclosure relates to a temporary closure device for a throughway comprises a sleeve to fit in the throughway and a core located in the sleeve. The core has an annular rupturable connection locating the core in the sleeve to prevent flow of fluids through the sleeve. The annular connection is rupturable by displacing the core axially in the sleeve to allow fluid to flow through the sleeve.

BACKGROUND TO THE INVENTION

1. Field of the Invention

This invention relates to temporary closure devices suitable for use in tube couplings and also to tube couplings incorporating temporary closure devices.

2. Background Prior Art

U.S. Pat. No. 4,269,237 discloses a device for draining and collecting sump oil from a motor vehicle having a drain plug which is closed by a ball valve or rupturable membrane. Oil is drained from the sump by inserting a drain spigot into the plug body to open the valve or to rupture the membrane so that oil drains through a hose connected to the spigot into a shallow vessel which may be located beneath the vehicle.

British Patent Specification No. 2182320 discloses a keystone bung and a cask connector for beverage casks. The bung has an outer periphery constructed to seal with a given keystone and a through bore closed by a sealing diaphragm. The through bore has an internal screw thread to mate with an external thread on the cask connector so that it can be screwed into the through bore and a tapered inner end of the connector can rupture the diaphragm to open the bung.

Summary of the Invention

This invention provides a temporary closure device for a throughway comprising a sleeve to fit in the throughway and a core located in the sleeve, the core having an encircling annular rupturable connection locating the core in the sleeve to prevent flow of fluids through the sleeve, the annular connection being rupturable by displacing the core axially in the sleeve to allow fluid to flow through the sleeve.

More specifically, the annular rupturable connection is formed by an annular web extending between the core and the sleeve.

Thus, in one arrangement according to the invention the web may be formed integrally with the core and has a rupturable connection with the sleeve.

For example, the annular web may be formed integrally with both the core and the sleeve, the connection between the web and the sleeve being rupturable to permit the core to move axially in the sleeve to allow flow through the sleeve.

In a further arrangement, the annular web may be bonded to the sleeve, the bond being rupturable to permit the core to move axially in the sleeve to allow flow through the sleeve.

In a still further arrangement, the throughway in the sleeve may have annular abutment means with which the web engages to locate the core in the sleeve and from which the web can be disengaged by pressing the core into the throughway to allow flow of fluid along the throughway.

In any of the above arrangement the sleeve may be an elongate sleeve having a front portion in which the core is located and a rear portion to which the core may be displaced to allow flow of fluid through the sleeve.

In the latter arrangement the rear portion of the sleeve may be formed with one or more axially extending slots in the wall of the sleeve through which fluid may flow when the core is located in the rear of the sleeve.

More specifically, a plurality of slots may be formed in the rear portion of the sleeve equispaced around the sleeve.

In the case where an elongate sleeve is provided and the core is moulded in the front portion of the sleeve, the core may have an end projecting from the front end of the sleeve with which a tube or other component can act to displace the core into the sleeve to open the passage through the sleeve. The projecting end of the core may taper from the integral annular web to the front of the core. Also, the front of the core may have an integral projecting cruciform shape to receive a tube or other component to displace the core.

In any of the above arrangements the sleeve and core may be moulded plastics components.

The invention also provides a tube coupling body having a throughway open at one end to receive a tube, a locking device in the throughway to engage and secure the tube in the throughway, a seal in the throughway beyond the locking device to engage and seal with the tube when the latter is fully inserted into the throughway and is engaged by the locking device and a closure device located in the throughway beyond the seal to be engaged by the tube as the latter is inserted into the throughway, the closure device incorporating a rupturable seal arranged to be ruptured by full insertion of the tube or pin to permit flow in the throughway.

The closure device may comprise a sleeve to be engaged in the throughway, a core located in the sleeve with a rupturable seal extending between the plug and sleeve, the plug being engaged by a tube or pin inserted into the throughway to rupture the seal with the sleeve and displace the plug along the sleeve to allow flow through the sleeve.

In the latter construction the closure device may comprise a sleeve and a core located in the sleeve, the sleeve having a front portion and a rear portion, the plug being located in and supported in the front portion of the sleeve by a thin breakable annular web formed integrally between the core and sleeve to prevent flow of fluids through the sleeve, the core being possibly displaceable into the rear portion of the sleeve and the rear portion of the sleeve having a passage or passages therein to permit flow of fluid passed the core when located in the rear portion.

More specifically, the rear portion of the sleeve may be formed with one or more axially extending slots in the wall of the sleeve through which fluid may flow when the core is located in the rear of the sleeve.

In one example according to the invention, a plurality of slots may be formed in the rear portion of the sleeve equispaced around the sleeve for fluid flow when the core is displaced into the rear portion of the sleeve.

In accordance with a further feature of the invention the core may be moulded in the front portion of the sleeve and may have an end projecting from the front end of the sleeve on which a tube or other component can act to displace the core into the sleeve to open the passage through the sleeve. Furthermore, the projecting end of the core may taper from the integral annular web to the front of the core and the front of the core may have an integral projecting cruciform shape to receive a tube or other component to displace the core.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring firstly toFIG. 1of the drawings, there is shown a tube coupling indicated generally at10and an end portion indicated at11of a tube which is inserted partway into the coupling. The tube coupling is generally of the type described and illustrated in my European Patent No. 829671 to which reference should be made for a detailed description of the coupling.

The coupling comprises a coupling body indicated generally at12comprising a short spigot13having a central throughway14and external annular ribbing15to engage and grip in a soft walled tube (not shown). The spigot of the coupling body leads into an enlarged diameter socket16having a bottom wall17with which the spigot is integrally formed. The throughway14in the spigot opens into an increased diameter bore18in the socket at an internal annular step19at the bottom of the socket facing outwardly of the socket. The socket has a further stepped increase in bore at20from which an enlarged diameter end portion extends to terminate in an open end22to the coupling body.

A collet indicated generally at23for locking a tube in the coupling body is mounted in the socket adjacent the open end thereof. The collet comprises an annular skirt24having a stepped outer surface formed with reduced diameter portion25at a step26which engages in the stepped bore18with the step26abutting the step20. The skirt24has a plurality of resilient arms27projecting towards the open end of the socket and is formed with inturned abutment teeth28to engage with a tube inserted into the coupling body.

A tube to engage in the coupling body is indicated at29. The tube has a reduced diameter end portion30which projects into the socket of the coupling body through the open end22, and has an integral encircling annular bead31with which the teeth28on the collet engage as the tube is inserted into the socket. As shown inFIG. 1, the tube is partially inserted into the socket and the bead31is in engagement with the outer sides of teeth28of the collet.

The bore18of the socket16contains, further along from the collet24, a first O-ring seal32to engage with the outer surface of the tube inserted into the socket, a spacer33and further O-ring seal34and finally a closure device indicated generally at35.

The detailed construction of the closure device is shown inFIGS. 3 to 6to which reference will now be made. The closure device comprises a sleeve37having a stepped bore the sleeve having a forward portion38in which the larger diameter bore is formed containing a slightly small diameter portion bore and a rear portion39. The sleeve is located between the second O-ring seal34in the socket and shoulder19where the socket reduces in diameter to the spigot13. The front portion of sleeve38contains a core comprising a central cylindrical portion40which is smaller in diameter than the internal diameter of the sleeve38to leave a gap41between the core and forward portion of the sleeve. The core is located in the sleeve by means of an annular web43of triangular cross-section formed integrally with the core and tapering to a apex formed integrally with the inner surface of the sleeve. The connection between the apex of the web and the inner surface of the sleeve is rupturable to release the core from the sleeve as will be described later.

The core has a frusto-conical portion42extending from the web43outwardly of the sleeve and to terminate in a projecting cross or cruciform abutment44at the forward end of the core. The opposite, rearward end of the core is formed with a similar cruciform projection45. The core is a close fit in the rear near portion39of the sleeve which has a plurality of slots46extending into the sleeve from the rearward end to allow flow of fluid around the core.

As indicated earlier, the apex of the web43connecting the core40to the forward portion43of the sleeve is rupturable and the cruciform abutment44at the front end of the core is designed to be engaged by the leading end of tube portion30as the latter is inserted into the connecting body and the raised bead31on the tube comes into engagement with the teeth28of the collet. On pressing the tube further into the socket of the coupling body, the end of tube forces the core35rearwardly breaking the connection of the core to the sleeve and driving the core into the rear part of the sleeve where fluid flow around the core can take place via the slots46in the sleeve. At the same time the raised bead31snaps past the tube28which then engage on the rearward side of the bead to hold the tube in the socket shown inFIG. 2.

The sleeve and collet are conveniently moulded in one piece in plastics material with the web formed integrally with the core and also integrally with the sleeve as described earlier. A modification of that arrangement, the core and sleeve may be moulded as separately components with the web being formed integrally with the core and the core can be secured and placed in the front portion of the sleeve by adhering the apex of the web with the sleeve which again provides as rupturable connection. In a further modification, the web on the core projects into a annular slot in the sleeve which holds the web and prevents flow past the core. An excess force to the core will, however, force the core along the sleeve thus disengaging the web from the slot.

In a further modification, the closure device may comprise the core and the front portion of the sleeve, the rear portion being omitted.

The tube coupling may be supplied with a “stuffer pin” formed integrally with the core to position the core in the coupling. The “stuffer pin” can be used to press the core through the sleeve to open the coupling for flow. The stuffer pin is designed to snap off the core in tension to allow it to be removed.