GB2568386A

GB2568386A - Conduit connectors

Info

Publication number: GB2568386A
Application number: GB1815871.7A
Authority: GB
Inventors: Kakaratsios Zacharias
Original assignee: Spirit AeroSystems Europe Ltd
Current assignee: Spirit AeroSystems Europe Ltd
Priority date: 2017-09-29
Filing date: 2018-09-28
Publication date: 2019-05-15
Anticipated expiration: 2038-09-28
Also published as: GB2568386B; GB201715840D0

Abstract

A connector 1 for connecting a conduit to an aperture in a barrier; the connector body having a stem 9 for connection at a first end to a conduit, and a flange surface 13 around a second end of the stem for sealing against a first side 5a of the barrier; the body having a lumen 17 extending through the first and second ends of the stem; a collar 19 having a bore 21 sized to receive the stem, and one end of the collar having a flange surface 23 around the bore for sealing against a second side 5b of said barrier; the stem and the collar configured to together define a retention mechanism 27 (e.g. a ratchet mechanism) when the collar is placed over the stem, to resist movement of the collar towards the first end of the stem. Embodiments include the above wherein the collar and/or stem comprise a severable portion, which in use can be preferentially severed so that the connector can be removed from the barrier. May be used for the connection of vacuum or resin injection hoses through a vacuum bag or tooling cavity during manufacture of composite articles.

Description

CONDUIT CONNECTORS

Field of the Invention

The invention relates to apparatus and methods for connecting a conduit to an aperture through a barrier. In particular, the invention concerns the connection of vacuum or resin injection hoses through a vacuum bag or tooling cavity during manufacture of composite articles.

Background to the Invention

Composite materials are widely used in a number of industries, such as aerospace, automotive, civil engineering and sports goods, due to their high strength-to-weight ratio.

Composite materials such as carbon fibre composite and fibreglass composite are formed from multiple plies or layers of fabric impregnated with and reinforcing a matrix phase. For example, a carbon fibre fabric is formed by carbonizing a synthetic polymer fabric material and may be provided in the form of woven fabric, non-woven fabric or may consist of unidirectional fibres. Similar composites may be formed using alternative fibrous materials, such as glasses or synthetic polymers (e.g. aramid), or combinations of such materials.

In the aerospace industry in particular, there has been increasing adoption of so called “out of autoclave” (OOA) manufacturing methods, due to their comparatively low operating costs in comparison to conventional autoclave methods.

In OOA vacuum assisted resin infusion methods, plies of a fabric are laid-up on a tooling surface to form a reinforcement lay-up, together with a resin distribution media (i.e. flow media) and covered with a vacuum bag. The vacuum bag is formed from a flexible or semiflexible material such as a plastics or silicone material, which is sealed to the tool surface around the periphery of the reinforcement lay-up.

Air is then extracted from the bag or the tooling cavity so as to compress the reinforcement lay-up and evacuate any air entrapped within the vacuum bag or the tooling cavity.

In vacuum assisted resin infusion applications, dry reinforcement is deposited or stacked to constitute the reinforcement lay-up. The reinforcement lay-up is then infused when resin is flowed into the vacuum bag from a feed reservoir driven by the pressure differential between the resin reservoir and the inside of the vacuum bag.

These processes require one or both of a resin infusion hose and a vacuum hose to be connected through apertures in the vacuum bag or tooling cavity.

It is vital for both types of connection to maintain the integrity of the vacuum. Leakage of air through the vacuum bag around the infusion or vacuum hoses (known as vacuum losses) can introduce defects into the infused composite. Vacuum losses can also present an environmental or health and safety hazard, as resin can escape through the fittings to the shop floor in extreme cases.

The defects in the laminate caused by loss of the vacuum integrity could include the increased interlaminar porosity, resin starvation and/or loss of compaction in regions of the composite. All of these effects can significant impair the structural properties of the cured composite article and can potentially lead to part scrapping.

Vacuum and infusion hose connectors typically include an internal fitting and an external fitting, one of which being adapted to connect to a hose or conduit, with the vacuum bag material being compressed between the internal and external fitting.

Most commonly, connectors utilise threaded fittings, such as those of Vacmobile (Auckland, New Zealand) or Airtech Europe (Differdange, Luxembourg). These are formed of a metal base threaded to or formed together with a stem which extends through the aperture in the vacuum bag. A lock ring is then threaded about the stem until compression is applied to both sides of the bag material by the lock ring and the base. A resin infusion or vacuum hose is then separately connected to the stem and held in place by another lock ring.

Connectors of this general type are relatively time consuming to install and disconnect. Installation is also prone to user error, by under tightening or overtightening the threaded fittings; either of which can cause vacuum losses.

Thermal expansion of the fittings can also cause leakage. For example, when the fittings expand and contract, particularly axially (i.e. in the direction along the length of the stem), this can lead to loosening of the threaded couplings. This can be particularly problematic in use of thick vacuum bagging materials, such as semi-flexible bags, because the stem portions are longer.

In addition, these fittings are relatively expensive to construct and so must be cleaned and prepared before each use.

Friction fittings are also known for use in vacuum bagging applications, in which a nozzle inside the bag is connected through a hole in the bag to a vacuum or resin hose, via a tapered friction fit. A seal around the stem or hose and against the bag is provided by a resilient or deformable collar disposed around the tube. Whilst these connectors are can be relatively rapidly installed, the quality of sealing depends on manually applying appropriate force to various parts, and so their performance can in practice be variable.

Accordingly, there remains a need for improved low cost connectors that can be more rapidly and reliably installed.

Summary of the Invention

According to a first aspect of the invention there is provided a connector for connecting a conduit to an aperture in a barrier;

a connector body having a stem for connection at a first end to a conduit, and a flange surface around a second end of the stem for sealing against a first side of a said barrier;

the body having a lumen therethrough, the lumen extending through the first and second ends of the stem;

a collar having a bore sized to receive the stem, and one end of the collar having a flange surface around the bore for sealing against a second side of a said barrier;

the stem and the collar configured to together define a retention mechanism when the collar is placed over the stem, to resist movement of the collar towards the first end of the stem.

In use the connector body may be engaged with a first side of the barrier, with the stem extending through an aperture in the barrier, and the collar placed or passed over the stem until the flange surfaces seal against the barrier. The retention mechanism prevents the collar from moving back towards the first end of the stem and so maintains the compression of the sealing media (i.e. O-rings, gasket) and thus the integrity of the seal. The retention mechanism is also less prone than solely threaded connections to loosening as the apparatus expands or contracts with temperature or is manipulated in use.

The connector may be rapidly and simply installed.

A retention mechanism includes mechanisms adapted to retain the collar in a fixed position in relation to the stem and resist motion in a first and/or a second direction. A retention mechanism may for example comprise formations which engage with one another when the collar and stem are in a particular position in relation to one another (or in one of more than one such retention positions), so as to resist motion in one or both directions of relative motion therebetween. A retention mechanism may comprise interlocking or cooperating formations, as disclosed herein. A retention mechanism may comprise formations that operatively engage with one another, as disclosed herein.

By retention mechanisms, we include non-return mechanisms and the like, adapted to permit motion between components in a first direction, and to prevent or significantly restrict motion between the components in an opposite second direction. In practice, a non-return mechanism may offer a limited resistance to motion in the first direction, and a higher, or much higher resistance to motion in the second direction - for example requiring breakage of the non-return mechanism in order to move in the second direction, or once such a mechanism is engages, resistance to motion in both directions may be provided. This is in contrast to a connection reliant only on friction, such as a solely threaded connection.

The stem and bore may be of any suitable cross section, but are typically cylindrical along at least a part of their lengths. The lumen may be axially disposed in relation to the stem and (in use) the collar.

At least a part of the stem and bore may be circularly cylindrical. In some embodiments, at least a part of the stem and bore may be keyed, for example by way of a non-circular cylindrical profile.

The flange surfaces may similarly be generally circular around the lumen. Conveniently, the body and collar are generally circularly symmetrical, for ease of manufacture and installation in any orientation. Other cross sectional profiles are also possible, such as polygonal profiles (e.g. hexagonal, octagonal, etc). Indeed different parts of the connector may have different profiles.

The stem may comprise one or more outward retaining formations disposed on or around the stem between the flange surface and the first end; and the collar may comprise one or more inward retaining formations being disposed in (i.e. on an inner surface of) or around the bore; wherein the outward and inward retaining formations are configured to engage with one another when the collar is placed over the stem with the flange surfaces opposed, and together define the retention mechanism.

A said outward retaining formation may be operable to cooperatively engage with a said inward retaining formation, when the collar is in a defined retention position in relation to the stem.

The collar and/or the stem may comprise more than one retaining formation, and so define more than one corresponding retention position.

The or each outward retaining formation may comprise a recess, indent or platform with which a said inward retaining formation may cooperatively engage, when the collar is in a defined retention position in relation to the stem.

The or each inward retaining formation may comprise a peg, sized to be received by an outward retaining formation formed as a recess or indent.

The or each outward retaining formation may comprise a platform, having a surface generally perpendicular to an axis through the stem. The or each inward retaining formation may comprise a corresponding ledge, having an opposed surface generally perpendicular to an axis through the stem.

The stem may, on its outer surface, define a channel (or slot) for guiding the path of the/each inward retaining formation. The channel may define a thread, along at least a portion of its length.

The channel may comprise the or each outward retaining formation. For example, a surface or surfaces of the channel (e.g. oriented towards the second end) may be provided with a recess, platform or indent. The channel may comprise one or more branches, into which an inward retaining formation may be “parked”. The branches (or indeed the recesses or indents) may extend towards the first end of the stem.

A surface of the channel may define a toothed profile, comprising along one or more portions thereof, a sawtooth or a ratchet (i.e. asymmetric) tooth profile. Accordingly, the toughs between the teeth may each define a retention position.

A surface of an inward retaining formation may comprise one or more complimentary teeth, or may comprise or function as a pawl.

In alternative embodiments, an inner surface of the bore may define a channel for guiding the path of the/each outward retaining formation. The channel may define a thread, along at least a portion of its length.

The channel may comprise the or each inward retaining formation; for example, a surface or surfaces of the channel (e.g. oriented towards the second end) may be provided with a recess, platform or indent, one or more branches or a toothed profile.

The stem may comprise one or more outer retaining formations, such as one or more pegs, ledges or other suitable projections.

In some embodiments, both the stem and the bore are threaded, with each thread comprising the one more inward and outward retaining formations (e.g. opposed toothed profiles).

The stem and/or the bore may comprise a plurality of respective retaining formations extending axially along at least a part of the length of the stem and/or bore as the case may be. Thus, the retention or non-return mechanism may be capable of adapting to a range of barrier thicknesses.

In some embodiments, the channel or slot may be threaded along at least a part of its length, and comprise a series of recesses, indents or platforms spaced along the threaded part of the channel.

In use, the collar can be threaded around the channel until the required distance between the flange surfaces is reached, and the or each inward retaining formation engaged with the nearest adjacent outward retaining formation along the channel (or vice versa, where the channel is provided within the bore).

Advantageously, in use with a resilient vacuum bag and/or a resilient surface or seal on one or both of the flanges, the inward and outward retaining formations are resiliently urged together. This may further resist motion of the collar toward the first and in some embodiments also the second end of the stem.

By inward and outward we refer to the orientation of the formations in relation to the stem and bore. The inward and outward formations may project from the adjacent portions of surfaces of the stem and bore, or may be recessed.

The retention mechanism, or non-return mechanism, may be a ratchet mechanism.

One or other of the one or more outward retaining formations and one or more inward retaining formations may be in the form of one or more pawls. The other of the one or more outward retaining formations and one or more inward retaining formations may be in the form of one or more asymmetric teeth.

The mechanism may comprise a plurality of pawls and/or a plurality of asymmetric teeth, which may be arrayed circumferentially and/or axially.

A pawl may thus ride over the asymmetric teeth when the collar moves towards the second end of the stem, and be retained between the asymmetric teeth and thereby resist motion towards the first end of the stem.

A pawl may be formed as a resilient tab, for example extending from the collar or the stem via an active hinge.

A pawl may be frangible, so as to facilitate removal of the collar from the stem by breaking the tab(s); for example by twisting or the application of sufficient force against the non-return mechanism.

The non-return mechanism may be symmetrical around an axis (typically along which the lumen runs).

One or both of the inward and outward formations may extend entirely around the stem or bore, as the case may be.

One or both of the inward and outward retaining formations may be cylindrically symmetrical. For example, an array of outward or inward retaining formations may be arranged around the bore of the collar or around the stem. Where the stem or the bore are polygonal in cross section, the said formations may be arranged evenly around the faces of the polygon.

Accordingly, the non-return mechanism may be formed when the collar is placed over the stem, regardless of the relative orientations of the collar and stem.

A symmetrical non-return mechanism may also assist in centring the collar in relation to the stem. This in turn allows for a degree of tolerance between the size of the bore and the stem.

The collar and/or the stem may comprise a severable portion, which in use can be preferentially severed so that the connector can be removed from the barrier.

A portion of the non-return mechanism, such as a pawl, may be severable.

The connector may comprise a clearance between the stem and the bore. Components of the non-return mechanism may extend across the clearance. For example, a pawl (e.g. a resilient tab) may extend across the clearance.

Accordingly, in use a tool may be introduced into the clearance to sever a portion of the nonreturn mechanism, to allow the collar to be removed.

The clearance may be accessible from the first end. The clearance may in use extend from the non-return mechanism and along the bore towards the first end.

The clearance may be generally annular.

The clearance may be tapered towards the first end, to facilitate insertion of a tool, as disclosed herein.

The stem may have a narrower diameter between the non-return mechanism (or component part thereof, such as an outward engagement formation) and the first end, so as to create a clearance in use. Alternatively, or in addition, the bore may have a wider diameter between the non-return mechanism (or component part thereof, such as an inward engagement formation), and the first end.

A portion of the collar may be severable.

For example, the collar may comprise a severable portion of the non-return mechanism, such as a severable (e.g. frangible) pawl.

A severable portion of the collar may comprise a line of weakness, extending around or generally parallel to the bore. The collar may thus be adapted to preferentially break along the line of weakness, so as to release the collar from the stem.

For example by the application of sufficient force may break the collar, e.g. by twisting the collar or introducing a tool to the line of weakness. A suitable arrangement might for example be a wedge driven into a notch, to prise the collar apart at the line of weakness, or a rotatable tool such as a pipe cutting tool (optionally also operable to sever the stem).

In some embodiments, a keyed interface between the collar and the stem may act as a cam to split the collar, for example along an axial line of weakness. In some embodiments, a keyed interface may couple rotation of the stem and the collar, so enable the stem to be snapped off by twisting the collar.

A severable portion of the collar may comprise a line of weakness around the collar between the flange surface and the non-return mechanism (or component thereof). Thus, when the collar and stem are severed, any remaining portion of the collar and stem are not retained by the non-return mechanism and the connector may be easily removed.

A portion of the stem may be severable.

For example, the stem may comprise a severable portion of the non-return mechanism, such as a severable (e.g. frangible) pawl.

A severable portion of the stem may comprise a line of weakness, extending around the stem. The line of weakness may be adapted to enable the stem to be snapped off after use, to facilitate removal of the connector, for example by twisting the collar.

The first end of the stem may comprise any suitable arrangement for connection to a conduit. In some embodiments, the first end of the stem comprises a barb fitting.

Other fittings, such as press fit, releasable collar connector, or Luer type connectors are also possible.

One or both of the flange surfaces may be flat. In use, sealing engagement to the barrier may be provided by an additional layer, such as a gasket or O-ring, between the barrier and flange surface(s), and/or the barrier itself may be sufficiently deformable to seal against a flat flange surface.

One or both of the flange surfaces may comprise one or more channels, for receiving an Oring or gasket the like.

The connector may comprise an O-ring or gasket disposed in said one or more channels.

An O-ring or O-rings may in use locally apply additional pressure against a deformable barrier, to thereby assist in sealing. In some embodiment, both of the flange surfaces comprise an O-ring, where the O-rings of the collar flange surface and the O-rings of the connector body flange surface have different diameters.

In use, an O-ring may at least partially project from one of the flange surfaces and the other flange surface may comprise an adjacent channel or indent. A flexible barrier may thus be deflected to some extent by the O-ring into the adjacent channel or indent.

One or both of the flange surfaces may be ridged. The ridges may in use locally apply additional pressure against a deformable barrier, or a gasket, to thereby assist in sealing.

The body may comprise a nozzle, extending from the lumen, such as a resin infusion nozzle.

The lumen may extend to a conduit junction, for placing a conduit connected to the stem in communication with a further conduit to the first side of the barrier.

In some embodiments, one or both of the connector body and the collar are of unitary construction. That is to say, they are formed from a single piece of material.

For example, the connector body and/or collar may be machined from a block of material, or may be cast or moulded in a single piece.

For example, the connector body and/or collar may be injection moulded from a plastics material, such as a thermoplastics material or engineered polymer. Examples include, but are not limited to polythene, PTFE, FEP, nylon (i.e. a polyamide), polyphenylenes (PPS), polyetherimides (PEI), polyether ether ketones (PEEK), polyarylether ketones (PAEK), or the like.

The connector body and collar can thus be made more efficiently than known connectors, out of fewer parts and at lower cost. Indeed, the connector body may be made cost effectively enough to be disposable after use, avoiding the need for preparation steps such as applying release agent, and the need to clean the parts after use.

The connector body and/or collar may be suitable (i.e. available at a low enough cost) for a single use. This avoids the need for parts to be cleaned after use, for example to remove resin. In addition, disposable components can be destructively removed, reducing composite manufacturing time.

The invention extends in a second aspect to a kit of parts for connecting a conduit to an aperture through a barrier, the kit comprising:

at least one connector body having a stem for connection at a first end to a conduit, and a flange surface around a second end of the stem for sealing against a first side of a said barrier; and the at least one connector body having a lumen extending the body having a lumen therethrough, the lumen extending through the first and second ends of the stem;

at least one collar having a bore sized to receive a said stem, and one end of the at least one collar having a flange surface around the bore for sealing against a second side of a said barrier;

each said stem and each said collar configured to together define a retention mechanism when a said collar is placed over a said stem with the flange surfaces opposed, to resist movement of the collar towards the first end of the stem.

Each stem may comprise one or more outward retaining formations disposed on or around at least a portion of the stem between the flange surface and the first end.

Each collar may comprise one or more inward retaining formations being disposed in or around the bore.

The kit may further comprise an installation tool, configured to apply a pre-determined pressure to a collar. The tool may be adapted to apply a predetermined torque to a collar, for example for embodiments in which a channel defies a thread along at least a part of its length.

The tool may have a collar engagement formation, such as a ring or curved jaws sized to engage with the collar, and a handle coupled to the collar engagement formation. For example, a collar may comprise a wider diameter region proximal to the flange surface, and the engagement formation may be sized to fit over or around a narrower diameter region of the collar and abut the wider diameter region.

The tool may be adapted to provide a haptic feedback if a force above a pre-determined threshold is applied between the handle and the engagement formation. Thus, in use an operator may apply a pressure to a collar positioned over the stem of a connector body, until the haptic feedback is received.

The engagement formation may be slidable with respect to the handle. Resistance to slideable motion may be provided by a resilient member, adapted to give way above a predetermined force. For example, a bow spring may be provided in an indent.

For some applications, the connector body may not rest against a firm surface. For example, in some methods, a connector body may be placed through a part of a vacuum bag resting over a reinforcement lay-up, such that undue pressure upon the connector body may deform or damage the reinforcement lay-up.

The tool may accordingly be adapted to apply opposing forces between a said body (or in particular a stem) and a said collar.

Accordingly, the tool may comprise a gripping portion, for gripping the connector body (most typically the stem) and an engagement formation, moveably coupled to one another along an axis and operable to apply a force along the axis therebetween.

One or other of the gripping portion and the engagement formation may be moveable in relation to a handle. The gripping portion and the engagement formation may be coupled via a torque release mechanism, such as a deflecting beam arrangement (comprising a peg and detent, adjustable wedge and resilient beam portion as known in the art).

In some embodiments, the tool is arranged whereby application of a force both tightens the gripping portion and applies a force along the axis between the gripping portion and the engagement formation - one or both of which may be released above a predetermined force along the axis.

Accordingly, a user can apply a force to the installation tool thereby gripping the connector body and applying up to a predetermined force between the connector body and the collar. This facilitates consistent installation of the connectors.

A predetermined force between the gripping portion and engagement formation may be applied pneumatically, by way of a pneumatic cylinder therebetween. A predetermined force may be applied by way of a torque wrench (e.g. a pneumatic or mechanical torque wrench), applied to a bolt between the griping portion and engagement formations.

The gripping portion may include a cap, adapted to engage with an end of the stem. For example, the gripping portion may comprise two or more opposing resilient legs for gripping around the stem.

The gripping portion may on an outer surface comprise a tapered portion, and may for example be generally conical.

The installation tool may comprise a tubular cap, an open end of which may function as the engagement formation. The tubular cap may be provided with a bore sized to slideably receive the gripping portion. Towards the closed end, the bore may include a narrowed portion, sized to fit over the narrowest part of the gripping portion, but narrower than the widest part of the gripping portion.

The gripping portion and engagement formation may be provided with a keying arrangement to resist relative rotation.

Accordingly, in use, a bolt may extend through the engagement formation and threadably engage with the gripping portion and the engagement formation. Thus, rotation of the bolt translates into sliding motion between the gripping portion and engagement formation and facilitate controlled application of a force along the axis of the stem, therebetween.

The kit may comprise a removal tool.

The removal tool may comprise a wedge driven into a notch, adapted to prise the collar apart at a line of weakness, or for insertion into a said clearance.

The removal tool may be or a rotatable tool such as a pipe cutting tool (optionally also operable to sever the stem).

In particular embodiments, the tool comprises an annular sleeve. The annular sleeve may be sized to be introduced into an annular clearance between the stem and the collar, so as to sever a portion of the non-return mechanism.

The invention extends in a third aspect to a method of connecting a conduit to an aperture in a barrier, the method comprising:

providing a connector body having a stem for connection at a first end to a conduit, and a flange surface around a second end of the stem for sealing against a first side of a said barrier, wherein a lumen extends from the first end of the stem and through the connector body; and providing a collar having a bore sized to receive the stem;

passing the stem through the aperture from a first side of the barrier;

placing the collar over the stem from a second side of the barrier, thereby forming a retention mechanism between the collar and the stem to resist movement of the collar towards the first end of the stem; and sealingly engaging a flange surface of the connector body around the aperture on the first side of the barrier and sealingly engaging a flange surface of the collar around the aperture on the second side of the barrier.

The retention mechanism may comprise one or more inward retention formation and one or more outward retention formations, of the bore and the stem, respectively. One of the bore and stem may define a channel, for guiding the path of the inward/outward retention formation(s) as the case may be.

The method may therefore comprise passing a said inward/outward retention formation along a said channel, when placing the collar over the stem, until a retention mechanism is formed.

The method may comprise applying a predetermined pressure to the collar. The method may comprise applying a predetermined torque to the collar.

The method may comprise applying a predetermined pressure or torque between the collar and the connector body.

A predetermined pressure may be applied using a tool as disclosed herein.

The method may further comprise connecting a conduit to the stem.

Removal of a connector as disclosed herein may be effected by applying sufficient force to move an inward/outward retention formation along channel in an opposite direction to that along which it was installed.

Alternatively, it may be quicker or more convenient for the connector, or one or both of the collar or stem to be single use items, and for removal to be achieved by breaking a part of the connector.

The invention also extends in a fourth aspect to a method of removing a connector from a barrier:

wherein the connector comprises:

a connector body having a stem for connection at a first end to a conduit, and a flange surface around a second end of the stem engaged (typically sealingly) against a first side of a said barrier, wherein a lumen extends from the first end of the stem and through the connector body; and a collar having a bore sized to receive the stem and a flange surface engaged (typically sealingly) against a second side of the barrier;

wherein the collar is retained on the stem by a retention mechanism between the collar and the stem to resist movement of the collar towards the first end of the stem;

the method comprising;

severing a portion of the collar or the stem so as to release the collar and the body from their engagement with the barrier.

Severance of a portion of the collar or stem may in addition release the collar from the body.

The method may comprise severing the collar axially, that is to say generally parallel to the lumen (and the stem). The method may comprise severing the collar radially, i.e. generally around the collar and stem.

The method may comprise severing a portion of the non-return mechanism.

The method may comprise inserting a removal tool into a clearance between the collar and the stem. The method may comprise applying a force to the tool (e.g. hitting an end of the tool with a hammer or the like) so as to sever a portion of the collar and or stem, such as a portion of the non-return mechanism.

The method may comprise twisting the collar with respect the stem, to sever a portion of the stem.

The method may comprise disconnecting a conduit from the first end of the stem, for example by cutting the conduit. This may be performed before using the removal tool, for example to allow the tool to be inserted over the stem and into an annular clearance.

The method may comprise removing the connector body and/or any remaining portions of the collar.

The method may comprise disposing of the connector, or any fragments thereof.

Further optional features of each aspect of the invention correspond to optional features of each other aspect of the invention. In particular, the methods of the third and fourth aspects disclosed herein may be performed using the connector apparatus, installation or removal tools described in relation to the first and second aspects.

Description of the drawings

Example embodiments will now be described with reference to the following figures in which:

Figure 1 is a cross sectional side view of a connector;

Figure 2 is a perspective view of a connector body;

Figure 3 shows (a) a perspective view; (b) a cross sectional side view; and (c) a bottom view; of a collar for the connector of Figure 1;

Figures 4(a)-(d) show cross sectional side views of the steps of installing a connector;

Figure 5(a) shows a perspective view of a gripping portion of an installation tool; Figures 5(b) and (c) show perspective and cross section views of an engagement portion of the installation tool; Figure 5(d) shows a cross sectional side view of the assembled installation tool and Figure 5(e) shows a cross sectional view of a connector and an installation tool engaged therewith;

Figure 6 shows (a) a cross sectional view and (b) a schematic perspective view of a connector and a removal tool;

Figure 7 shows an alternative embodiment of a connector;

Figure 8 shows a schematic perspective view of a still further embodiment of (a) a connector body through an aperture in a barrier and (b) a connector following installation of a collar;

Figure 9 shows an alternative embodiment of an installation tool;

Figure 10 shows (a) a perspective view and (b) a close up perspective view of the connector body of an alternative embodiment a connector;

Figure 11 shows (a) a perspective view and (b) a plan view of a collar of the alternative embodiment of a connector.

Figure 12 shows (a) a side view and (b) a close up side view, of another embodiment of a connector body.

Detailed Description

Figure 1 shows an embodiment of a connector 1 for connecting a conduit to an aperture 3 in a barrier 5 (in the embodiment shown, a flexible vacuum bag material for use in vacuum assisted resin infusion methods of composites).

The connector has a connector body 7, with a stem 9. The first end 11 of the stem is provided by a barbed fitting, for connection to a conduit (not shown). Other types of fittings may be provided to connect a conduit to the stem, in other embodiments.

At the second end 13 of the stem, the connector body 7 has a flange surface 15. The flange surface 15 extends around the second end 13 of the stem 9 and is adapted to in use seal against the first side 5a of the barrier 5 around the aperture 3.

The connector body also has a lumen 17 extending through the body, which runs from the first end to the second end of the stem, along an axis A. The end of the lumen extends through the distal end 10 of the connector body, such that the connector 1 functions in use as an injection nozzle for injecting resin or extracting resin and air into a reinforcement layup during resin infusion manufacturing methods.

In other embodiments (not shown) the portion of the connector body on the first side of the barrier is configured to be coupled (e.g. via a t-piece) to other conduits, or is provided with an alternative nozzle or vacuum inlet configuration.

The connector 1 further comprises a collar 19, having a bore 21 through the collar sized to receive the stem. The collar 19 also has a flange surface 23 around the bore 21 at one end of the collar which is adapted in use to seal against the second side 5b of the barrier 5.

As best seen in the expanded view of region B, shown in the inset to Figure 1, the stem and collar together define a non-return mechanism (indicated generally as 27). When the collar is placed over the stem as shown in Figure 1, the non-return mechanism resists movement of the collar 19 towards the first end 11 of the stem 9.

The non-return mechanism 27 consists of an array of annular asymmetric teeth 29 (which are asymmetrically ramped obliquely to the axis A towards the first end of the stem, and generally normal to the axis A towards the second end of the stem). The teeth 29 are outwardly extending from the stem 9. The non-return mechanism 27 also includes an annular array of pawls 31, which are inwardly extending from the collar 19 in a ring around the bore 21. The pawls 31 are also asymmetrically ramped, but in the opposite orientation to the teeth 29. Thus, in use the obliquely ramped surfaces of the teeth 29 and the pawls 31 slide past each other when the collar is moved in the direction from the first end 11 to the second end 13, whilst the surfaces normal to the axis A engage to prevent motion from the second end to the first end.

Both the connector body 7 and the collar 19 are of unitary construction, and can conveniently be manufactured at low cost from plastics by injection moulding. Accordingly, the pawls can pass over the teeth 29 by virtue of the inherent flex in the plastics material itself. In alternative embodiments, the pawls or teeth may be resilient and for example be moveable about active hinges.

To assist in sealing the flange surfaces 15, 23 against the barrier 5, around the aperture 3, the flange surfaces are provided with O-rings 33, 35 disposed in channels 37, 39 in the flange surfaces. The thickness of the O-rings is greater than the depth of the channels.

Figure 2 shows a perspective view of the connector body 7, in which the annular outwardly facing teeth 29 can be more clearly seen extending along a portion of the length (axially) of the stem 9. The pawls 31 can engage with any one of the teeth 29 and thus the connector 1 is in use able to adapt to different barrier thicknesses.

The channel 37 in the flange surface 15 can also been seen in Figure 2.

The stem reduces in diameter towards the first end. Thus, the portion 41 having the outward retaining formations 29 has a wider diameter than the portion 43 provided with the barb fitting.

A collar 19 is shown in Figure 3. As most clearly seen in the cross sectional side view of Figure 3(b), the bore 21 through the collar is of constant diameter and is sized to closely fit around the wider portion 41 of the stem 9 (allowing only sufficient space for the inward and outward retaining formations 31,29 to slide past one another).

Accordingly, a clearance 45 is defined between the inner walls of the bore 21 and the narrower portion 43 of the stem 9 (as shown in Figure 1). As described in further detail below, the clearance 45 provides access from the first end for a removal tool to remove the collar from the stem, and thus effect removal of the connector 1 from the barrier 5.

Also visible in the Figures 3(b) and (c) is the circumferential array of pawls 31 disposed around the axis A of the collar 19. In alternative embodiments, the collar may comprise a pawl which is a continuous ring or ring, or an array of asymmetric teeth along the axis A.

The collar further includes a wider-diameter shoulder 47, adjacent to the flange surface 23. In use, pressure may be applied to the shoulder to install the connector to the barrier, as described in further detail below.

With reference to Figures 4(a)-(d), the connector can be used to connect a conduit to the aperture 3 as follows.

In a first step, the stem 9 of the connector body 7 is pushed through the aperture 3 in the barrier 5, from the first side 5a. For example, the first side of the barrier may be the inside surface of a vacuum bag. Figure 4(a) shows the connector body after the first step.

In a second step, a collar 19 is placed over the stem 9 from the second side of the barrier and a force applied between the collar and the connector body 9 so that the opposed flange surfaces 15, 23 (and more particularly the O-rings 37, 39) form a seal against the first and second surfaces 5a, 5b of the barrier 5, around the aperture 3. This step may be conducted manually, or a tool may be used to apply a predetermined pressure, as described below.

In a third step, a conduit 51, such as a resin infusion or vacuum conduit is attached to the first end of the stem. This step may also be conducted manually, for example where a conventional barb fitting and polyethylene (or, for higher temperature applications, PTFE) tubing is used. In other cases, for example where the tubing is stiffer (e.g. thicker) or a tighter seal is required, a tool may be used as known in the art.

Optionally, in a fourth step, a further seal 53, previously around the conduit, may be slid down onto the collar. In the case where residual leakage occurs between a vacuum conduit and the stem, the additional seal is present to seal around the conduit and against the collar, such that the additional seal 53 thereby defines a low pressure volume together with the clearance 45 between the collar and the stem.

The additional seal 53 may be formed from a malleable mastic material, or an elastomeric material. Alternatively, a mastic tape may be wrapped around the top of the collar in a fourth step.

An alternative embodiment of the second step is shown in Figure 5(d). Figures 5(a)-(c) show the component parts of an installation tool (indicated generally as 55).

The tool 55 has an engagement formation 57 for applying pressure to the shoulder 47 of the collar, and a gripper portion 59.

A perspective view of the gripper portion 59 is shown in Figure 5(e). The gripper portion has opposed legs 400 and 402, configured to clip to the top of a barb fitting. The outer faces of the legs define a part of a frustoconical surface, and taper outwardly from the upper end 404 to the lower end 406 of the gripper portion 59. At its upper end, the gripper portion is provided with an internally threaded aperture 408, for receiving a bolt; as discussed below.

In the embodiment shown, the legs 400, 402 are provided with cut-out portions 410, to facilitate flexing so that the gripper portion 59 can be readily clipped onto a barb fitting.

Each leg 400, 402 is also provided with an outwardly projecting tab 412, sized to cooperate with a corresponding slot within the engagement formation 57.

Figure 5(b) shows a perspective view of an engagement formation, in the form of a cylindrical cap 57. The cap has a closed upper end 414, provided with a hole 416. The bottom end 418 of the cap 57 is open and extends to a bore shaped to fit over a collar 19.

Figure 5(c) shows a cross sectional view of the cap 57 along the axis A. A lower portion 420 of the bore has a shape corresponding to the shape of a collar 19. A collar 19 can fit into the bore, but not beyond the line a.

An intermediate region 422 of the bore has a narrower diameter than a collar 19, but a wider diameter than the gripper portion 59 (including the tabs 412).

An upper region 424 of the bore is generally conical, and is provided with a taper 426 than corresponds to the outer surfaces of the legs 400, 402 of the gripper 59. The length along the axis A of the upper portion 424 is greater than the length of the gripper portion 59.

The upper region 424 also includes parallel slots 428 which extend parallel to the axis A and are sized to receive the tabs 412 ofthe gripper portion 57, as shown in Figure 5(d). The gripper portion 57 is thus able to slide along the axis, but its rotation about the axis in relation to the engagement formation 59 is prevented.

Figure 5(d) shows the assembled tool 55, ready for use. A bolt 430 extends through the aperture 416 and threads through the aperture 408. Accordingly, rotation ofthe bolt around the axis A is translated into axial motion of the gripper portion 59. Moreover, since the upper portion 424 of the bore is longer along the axis A than the gripper portion 59, the bolt can be rotated to move the gripper 59 close to the line b, in which there is sufficient space for the legs 400, 402 to bend outwardly and clip onto the uppermost barb of a stem 9, as shown in Figure 5(e).

In this configuration, the gripper portion 59 grips the stem 9, and the lower region 420 fits snugly over the collar 19, such that at least the shoulder 47 abuts the corresponding surface of the engagement formation 57. As the bolt 430 is rotated, the gripper is urged into the upper region 424 of the bore, until further movement is prevented by the engagement of the legs 400, 402 around the stem 9. Further rotation of the bolt results in the opposing forces being applied along the axis A between the gripper portion 59 and the cap 57, and thus between the stem 9 and body 7 (illustrated by the arrow D).

By use of a conventional torque wrench to rotate the bolt 430, a predetermined force between the body and the stem can be applied.

Removal of the tool is facilitated by reversing the direction of rotation of the bolt, until the gripping portion is sufficiently far down the upper region 424 to be pulled from the stem.

The installation tool 55 in the embodiment shown is generally cylindrical, but in alternative embodiments may apply pressure evenly on two, three or more regions around the shoulder.

Mechanical force or torque limiting arrangements are also envisaged. For example an alternative installation tool is shown in Figure 9.

The tool 500 has an engagement formation 557 and a gripping formation 559, each having tines sized to fit around the collar 19 and the barbs of the stem 9, respectively. These are operatively connected to a handle portion 502, via a linkage portion 504 (connected by armatures 506 and pivot pins 508, which are slideable within rails 510 as shown in the figure). By squeezing the upper and lower parts of the handle 502 together (in the direction of arrows C), forces are translated to move the engagement and gripping parts 557, 559 apart, in the direction of arrows D.

Optionally, a predetermined force can be applied by way of a torque spring release gear around the central pivot pin 412 connecting the armatures 508. Above a predetermined torque the gear releases and decouples the handle from the engagement and gripping parts 557, 559.

Use of an installation tool ensures that the required sealing force is applied by the connector around the aperture in the barrier. Commonly, a number of such connectors must be installed during vacuum assisted resin transfer infusion methods, and they can be installed consistently using the installation tool.

Figures 6(a)-(b) show an arrangement for removing the connector. Initially, the conduit can be cut above the first end 11 of the connector body 9. Then a removal tool 61 can be introduced over the stem, into the remaining clearance 45 between the collar 19 and the stem 9.

The removal tool 61 has a cylindrical portion having a sharpened open end 63, and an end cap 65 at the upper end. The cylindrical portion is sized to slide relatively tightly within the bore 21 of the collar, to engage with the non-return mechanism, as shown in the Figure.

In order to remove the connector 1, an impulse is applied (manually or with a hammer, or the like) to the end cap 65 to propel the sharpened end 63 downwards so as to sever the pawls 31. The tool 61 and the end cap are then free to be removed from the stem, and the stem extracted from the aperture 3 in the barrier.

Other arrangements for removing the collar are also possible. For example, a pipe cutting tool (not shown) may be applied to the collar above the shoulder (see the level E marked in Figure 3(b)) so as to sever the collar and the stem radially, below (in the orientation shown in the figures) the non-return mechanism.

In still further embodiments, the collar may be severed axially, and may be provided with a line of weakness for this purpose.

Alternative embodiments of a connector are shown in Figures 7 and 8.

The features of the connector 100 shown in Figure 7 in common with the connector 1 are provided with like reference numerals, incremented by 100.

The connector 100 is configured generally as the connector 1, however the flange surfaces 115, 123 of the connector body 107 and the collar 119 are of wider diameter. The annular channel 137 set into the connector body flange surface 115 is of smaller diameter than the annular channel 139 set into the opposing collar flange surface 123. A flexible vacuum bag 105 compressed therebetween thus follows a more serpentine path radially away from the axis A1. The seals formed by the O-rings 133 and 135 are therefore also radially spaced apart, effectively providing two barriers to fluid. This “staggered” sealing arrangement may be of particular benefit in use of thinner vacuum bagging materials, which are better able to conform to a serpentine pathway, and in addition less susceptible to forming a compressive seal using directly opposed O-rings as for the connector 1.

The features of the connector 200 shown in Figure 8 in common with the connector 1 are provided with like reference numerals, incremented by 200.

Unlike the connector 1, which has a circular symmetry around its axis A, the connector 200 has a polygonal (in this instance 10 sided) symmetry around the axis A2. The outward retaining teeth 229 are also polygonal, and the bore 221 through the collar 219 is similarly profiled to snugly fit over the lower portion 241 of the stem 209. In addition, the collar 219 is frangible along an axial line of weakness 267 (a thinned portion).

The connector 200 can be installed and used generally in the manner of the connector 1. In order to remove the collar, it can be twisted with sufficient force to sever it along the line of weakness 267. The twisting may be applied using a conventional wrench, by way of the polygonal outer profile, or manually.

In alternative embodiments, the stem is instead provided with a radial line of weakness at the second end, adjacent to the connector body flange surface, such that a twisting force applied to the collar (optionally against an opposing force applied to the base at the other side of the barrier) causes the stem to shear and sever, releasing the connector; which can then be disposed of.

One or more of each of the collars and connector bodies disclosed herein may be provided in a kit form, optionally together with the installation and removal tools.

Figures 10 and 11 show the connector body 607 and collar 619 of an alternative embodiment of a connector. Features in common with the body 7 and collar 19 are provided with like reference numerals, incremented by 600.

As shown in Figure 10(a), the body 607 has a stem 609 with a wider portion 614 towards the second end thereof. A channel 660 is defined on the outer surface of the stem portion 641. A close up view of region X of the stem is shown in Figure 10(b).

The channel includes an entry portion 662 and the portion 664 of the channel defines a thread.

The lower surfaces 666 of the channel, oriented towards the second end 613 of the stem 609, are provided with a series or array of indents 666. As will be described in further detail below, the indents are examples of outward retaining formations, forming part of a retention mechanism in use.

Referring now to Figures 11(a) and (b), the collar 619 has a bore 621 therethrough, sized to be received over the wider portion 641 of the stem 609. The upper part 622 of the collar 619 is provided with a hexagonal profile, to assist in gripping and turning the collar (e.g. using a torque wrench) in use.

Protruding from an inner surface of the bore 621 are pegs 668, disposed on opposite sides of the bore. The pegs are sized to be received within the channel 660. The pegs 668 are examples of inward retaining formations.

In use, the collar is inserted over the end of the stem, and the pegs fall into the entranceway 662 when aligned therewith. The entranceway may be somewhat tapered to assist in this regard.

The channel then guides the path of the pegs along the threaded portion 664, as the collar is advanced towards the second end of the stem.

The indents 666 is sized to cooperate with the pegs 668. In the embodiment shown, the pegs are cylindrical, and the indents have a corresponding part cylindrical surface. Thus, each indent 666 and peg 668 together function as a retention mechanism, when a peg is urged upwardly (i.e. towards the first end of the stem) into an indent. Moreover, each position in which a peg is received in an indent represents a potential retaining position.

In use, the collar can be advanced towards the second end of the stem, generally as described above in relation to the connector 1, until the flange surfaces 615 and 623 are against a flexible bag material. When a nominal torque has been applied (either using a tool or manually based on a user’s experience), the bag material and/or the O-rings are compressed and apply a force urging the collar towards the first end of the stem.

The collar is then moved ether clockwise or anticlockwise, until the pegs 668 are forced into the next available indent 666, thereby forming a retention mechanism. The additional force required to move the out of the indent thus resists movement of the collar in relation to the stem in either direction.

Following use, the collar may be removed by severing a portion thereof, as disclosed above. Alternatively, a force may be applied towards the second end of the stem, sufficient to move the pegs from the indents, and allow the collar to be unscrewed.

Figure 12(a) shows a still further embodiment of a connector body 707. Features in common with the connector body 607 are provided with like reference numerals, incremented by 100. Figure 12(b) shows a closes up view of the region Y of the wider portion 741 of the stem 709. The stem portion 741 also defines on its outer surface a channel 760, having a tapered entranceway 762.

The outward retaining formations in this embodiment are flattened surfaces 766, which are generally perpendicular to the axis of the lumen 717 through the body 707 and positioned at 45, 90 or 180 intervals around the threaded portion 764 of the channel 760.. In alternative embodiments (not shown) the surfaces are slightly non-parallel (e.g. 5-10 degrees from parallel) to the lumen 717, to face slightly along the direction of the threaded portion of the channel.

In use with the collar 619 , the channel 760 guides the path of the pegs 668. When a nominal torque has been applied, the pegs are urged towards the first end 711 of the stem 709, as described previously. When the pegs rest, or are operatively engaged with the surfaces 766, there is no component of force between the surfaces 766 and the pegs 668 urging the pegs counterclockwise along the channel. Thus, in combination with the friction between the O-rings and the vacuum bag, the retention mechanism thus formed resists such motion. In embodiments where the surfaces 766 point slightly in the clockwise direction along the channel, a component of force is applied between the pegs and the surfaces 766 to urge the pegs clockwise.

Whilst the connector body 707 may be used in conjunction with the collar 619, in alternative embodiments (not shown), the pegs are instead replaced by platforms, oriented so as to cooperate with the surfaces 766, when in alignment therewith. As disclosed above, complimentary sawtooth or ratchet tooth profiles for the inward and outward retaining formations are also possible.

Whilst exemplary embodiments have been described herein, these should not be construed as limiting to the modifications and variations possible within the scope of the invention as disclosed herein and recited in the appended claims.

Claims

1. A connector for connecting a conduit to an aperture in a barrier;

2. The connector of claim 1, wherein stem and bore are cylindrical, and optionally circularly cylindrical, along at least a part of their lengths.

3. The connector of claim 1 or 2, wherein the stem comprises one or more outward retaining formations disposed on or around the stem between the flange surface and the first end; and the collar comprises one or more inward retaining formations being disposed in or around the bore; wherein the outward and inward retaining formations are configured to engage with one another when the collar is placed over the stem with the flange surfaces opposed, and together define the retention mechanism.

4. The connector of claim 3, wherein a said outward retaining formation is operable to cooperatively engage with a said inward retaining formation, when the collar is in a defined retention position in relation to the stem.

5. The connector of claim 4, wherein the collar and/or the stem comprises more than one said retaining formation, so as to define more than one corresponding retention position.

6. The connector of any of claims 3 to 5, wherein the or each inward retaining formation comprises a peg, sized to be received by an outward retaining formation formed as a recess or indent.

7. The connector of claim 6, wherein the or each outward retaining formation comprises a platform, having a surface generally perpendicular to an axis through the stem and wherein the or each inward retaining formation comprises a corresponding ledge, having an opposed surface generally perpendicular to an axis through the stem.

8. The connector of any one of claims 3 to 7, wherein the stem, on its outer surface, defines a channel for guiding the path of the/each inward retaining formation; and wherein the channel comprises the or each outward retaining formation.

9. The connector of any one of claims 3 to 7, wherein an inner surface of the bore defines a channel for guiding the path of the/each outward retaining formation; and wherein the channel comprises the or each inward retaining formation.

10. The connector of claim 8 or 9, wherein the channel defines a thread, along at least a portion of its length.

11. The connector of any one of claims 8 to 10, wherein both the stem and the bore are threaded, wherein each thread comprises the one or more inward and outward retaining formations.

12. The connector of any preceding claim, wherein the retention mechanism is a ratchet mechanism.

13. The connector of claim 13, wherein the said mechanism comprises a plurality of pawls and/or a plurality of asymmetric teeth, optionally wherein the pawls and/or teeth are arrayed circumferentially and/or axially.

14. The connector of any preceding claim, wherein the collar and/or the stem comprises a severable portion, which in use can be preferentially severed so that the connector can be removed from the barrier.

15. The connector of claim 14, wherein a severable portion of the collar and/or stem comprises a line of weakness, extending around or generally parallel to the bore or extending around the stem, as the case may be.

16. The connector of any preceding claim, wherein the first end of the stem comprises a barb fitting.

17. The connector of any preceding claim, wherein one or both said flange surfaces comprise one or more channels, for receiving an O-ring.

18. The connector of claim 17, comprising an O-ring or gasket in said one or more channels.

19. The connector of claim 18, wherein the O-rings of the collar flange surface and the O-rings of the connector body flange surface have different diameters.

20. The connector of any preceding claim, wherein the connector body comprises a nozzle, extending from the lumen, such as a resin infusion nozzle.

21. The connector of any preceding claim, wherein one or both of the connector body and the collar are of unitary construction.

22. The connector of claim 21, wherein the connector body and/or collar are injection moulded from a plastics material.

23. A kit of parts for connecting a conduit to an aperture through a barrier, the kit comprising:

each stem and each collar configured to together define a retention mechanism when a said collar is placed over a said stem with the flange surfaces opposed, to resist movement of the collar towards the first end of the stem.

24. A kit according to claim 23, wherein each stem comprises one or more outward retaining formations disposed on or around at least a portion of the stem between the flange surface and the first end;

wherein each collar comprises one or more inward retaining formations being disposed in or around the bore; and wherein the outward and inward retaining formations are configured to engage with one another when a said collar is placed over a said stem with the flange surfaces opposed, and together define a retention mechanism.

25. The kit according to claim 23 or 24, further comprising an installation tool, configured to apply a pre-determined pressure or torque to a collar.

26. The kit according to any one of claims 23 to 25, comprising a removal tool.

27. The kit according to claim 26, wherein the removal tool is a rotatable pipe cutting tool.

28. A method of connecting a conduit to an aperture in a barrier, the method comprising:

passing the stem through the aperture from a first side of the barrier;

29. The method of claim 28, wherein the retention mechanism comprises one or more inward retention formations and one or more outward retention formations, wherein the bore comprises the one or more inward retention formations and the stem comprises the one or more outward retention formations; and wherein one of the bore and stem defines a channel, for guiding the path of the or each inward or outward retention formation as the case may be;

and wherein the method comprise passing a said inward or outward retention formation along a said channel, when placing the collar over the stem, until a retention mechanism is formed.

30. The method of claim 28 or 29, comprising applying a predetermined pressure or torque to the collar, or applying a predetermined pressure between the collar and the connector body.

31. The method of any of claims 28 to 30, may further comprising connecting a conduit to the stem.

32. A method of removing a connector from a barrier:

wherein the connector comprises:

a connector body having a stem for connection at a first end to a conduit, and a flange surface around a second end of the stem engaged against a first side of a said barrier, wherein a lumen extends from the first end of the stem and through the connector body; and a collar having a bore sized to receive the stem and a flange surface engaged against a second side of the barrier;

the method comprising;