Field of the invention

The present invention relates to a connector assembly. Embodiments of the present invention seek to provide a mechanical engagement between a cylindrical component and a second component at least part of which extends around the outside of the cylindrical component. Embodiments of the present invention are applicable to forming a container or housing from a cylindrical component and one or more end components.

Background of the Invention

A wide variety of cylinder-based containers and housings are available. These may be formed of a cylindrical part and one or two end faces. The end faces may be coupled to the cylindrical part in a variety of ways, such as using adhesives, or by way of mechanical engagement (for example using screws). Each of these methods has its associated advantages and disadvantages. For example, adhesives are permanent, while mechanical engagement often requires very accurate manufacturing tolerances, can be time consuming to assemble and disassemble, and may utilise many small parts which can be easily lost.

The present invention seeks to provide a new way of connecting a cylindrical component to a second component (for example an end face, such as a base or lid of a container or housing) which provides improved performance and utility compared with existing techniques.

Summary of the invention

According to an aspect of the present invention, there is provided a connector assembly for providing a mechanical engagement between a cylindrical component and a second component at least part of which extends around the outside of the cylindrical component, the connector comprising:

a groove in and extending around an outer surface of the cylindrical component; a ring provided within the groove and projecting out beyond the outer surface of the cylindrical component;

a first engagement surface of the second component for contacting a first projecting part of the ring; and

an annular component extending around the outside of the cylindrical component and carrying a second engagement surface for contacting a second projecting part of the ring;

l wherein the annular component is movably mounted to the second component so that as it is moved towards the second component the ring is trapped between the first engagement surface, the second engagement surface and the inside of the groove.

Axial movement between the cylindrical component and the second component may thus be constrained by the engagement of the ring with each of the groove, the first engagement surface and the second engagement surface.

In some implementations, the first engagement surface, the second engagement surface and the inside of the groove are shaped to substantially conform to the natural cross section of the ring when the annular component is at its closest proximity to the second component. Typically in this case, little or no compression of the ring may take place. In other implementations, the ring is compressed between the first engagement surface, the second engagement surface and the inside of the groove when the annular component is moved towards the second component. In this case, the ring may be resiliently

compressible, and be reversibly deformed when compressed between the first engagement surface, the second engagement surface and the inside of the groove. Alternatively, the ring may be malleable, and be permanently deformed when compressed between the first engagement surface, the second engagement surface and the inside of the groove. An example of a suitable resiliently compressible (deformable) material is rubber or other elastomeric material. An example of a suitable malleable material could be a soft metal such as copper, which would be subject to plastic deformation when crushed between the first and second engagement surfaces and the inside of the groove.

In one example, the annular component and the second component are in threaded engagement with each other. However, other forms of moveable coupling (such as a ratchet based engagement) are also envisaged.

Preferably, a stop is provided for inhibiting the movement of the annular component towards the second component. The stop may comprise a first stop surface adjacent to the first engagement surface on the second component against which a second stop surface adjacent to the second engagement surface on the annular component comes into contact when the annular component is moved towards the second component. In this way, over- compression of the ring and damage to the apparatus by forcing the second component and annular component together can be avoided.

The ring may have a substantially circular cross section when in its uncompressed state. Depending on the shape of the groove and engagement surfaces, the ring may have a non-circular cross section when in its compressed state. In this case, the first engagement surface may comprise a compression surface which is substantially tangential, or at least angled, to the surface of the ring prior to the ring being crushed. Similarly, the second engagement surface may comprise a compression surface which is substantially tangential to the surface of the ring prior to the ring being crushed. Alternatively, the ring may have a cross section which is one of a regular polygon or an irregular shape. The first engagement surface may comprise a step which is substantially perpendicular to the outer surface of the cylindrical component, and which contacts the first projecting part of the ring where it projects from the groove.

The second component may form or be mounted to an end to the cylindrical part, the second component comprising a recess into which one circular edge of the cylindrical part is inserted until the first engagement surface comes into contact with the ring.

In the case of a rubber ring with a circular cross section, the ring when fully compressed may for example occupy between 79% and 91 % of the volume bounded by the groove, the first engagement surface and the second engagement surface. This degree of compression with this type of ring has been found to provide a strong mechanical joint, without causing damage to the ring. For other ring materials and/or other cross sectional shapes, these figures can be expected to be different. According to another aspect of the present invention, there is provided a container, housing or pipe comprising a connector assembly according to the above. In the case of a container, this may comprise a cylindrical body and two end faces, one or both of the end faces being connected to the cylindrical body using a connector assembly according to the above.

The present invention is useful in any application where a connection between two or more cylindrical and/or annular components is required, for example, in tube or pipe fittings or to connect or seal any type of cylindrical container.

Detailed description of the invention

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

Figure 1 schematically illustrates a connector assembly in an unlocked state;

Figure 2 schematically illustrates the connector assembly of Figure 1 in a locked state;

Figure 3 is a schematic 3D cross section of a connector assembly without the annular component (bezel) being present;

Figure 4 is a schematic 3D cross section of the connector assembly with the annular component (bezel) being present and engaged;

Figure 5 is a schematic 2D view of Figure 4, clearly showing compression of the ring after engagement of the bezel; Figure 6 schematically illustrates a transparent cylindrical container having a base and a roof, each of which are connected to the cylindrical part using the connector assembly of Figures 3 to 5;

Figure 7 schematically illustrates an exploded view of the embodiment shown in Figure 6;

Figures 8A and 8B schematically illustrate an alternative geometry for the connector assembly of Figures 1 and 2;

Figures 9A and 9B schematically illustrate another alternative geometry for the connector assembly of Figures 1 and 2; and

10A and 10B schematically illustrate yet another alternative geometry for the connector assembly of Figures 1 and 2.

Referring first to Figure 1 , a schematic cross section through a portion of a connector assembly for connecting, locking together and potentially sealing two or more radial components is shown. The connector assembly in this case comprises four parts, these being an inner cylindrical part A, an outer part B (which may itself be a cylinder or have a cylindrical part), an annular part C (referred to herein as a bezel), and a resiliently deformable ring part 4D which may for example be an O-ring formed of rubber or other resiliently crushable material. In practice, the present invention is (as will be described below) using the O-ring in an unusual way, by deforming it out of its torus (circular cross sectional) shape - this shape usually being substantially preserved under compression to provide a tight seal. More generally, the present technique utilises a resiliently deformable (compressible) ring, such as an O-ring to provide a mechanical joint between two elements, rather than providing a watertight seal between two elements which are mechanically connected by other means.

Taking each of the four parts in turn:

A) The inner cylinder A has a groove E in which an O-ring D is located.

B) The outer part has a step F and an angled compression surface G, rising to a stop H, and a female thread I.

C) The bezel C has an angled compression surface J, rising on one side to an inner face K), rising on the other side to a stop L, and a male thread M matched to the female thread of the outer part. It should be understood that alternative stop locations could be created, such as might be formed by the lower surface below male thread M.

D) The O-Ring D has an internal diameter matched to the circumference of the groove E in the inner cylinder and has a cross section such that the part of O-ring D which protrudes from the outer surface of cylinder A becomes compressed by the compression surfaces G and J of the outer part B and the bezel C respectively. Bezel C is screwed onto the outer part B, compressing O-ring D to form an annular lock with the cylinder part A. . An explanation of the usage of this four part assembly will now be provided, with reference both to Figure 1 (assembly in "unlocked" state) and Figure 2, which provides a cross section similar to that of Figure 1 , but in which the assembly is in a "locked" state. The following steps are taken in order to connect together the inner cylinder A and the outer part B.

1. The O-Ring D is installed into the inner cylinder A such that it is seated within the groove E (as shown in Figure 1).

2. The inner cylinder A is then inserted into the outer cylinder B such that the O- ring meets or engages with the step F of the inner cylinder (Figure 1).

3. The bezel 3 is rotated until its male thread M engages with the female thread I of the outer cylinder B (Figure 2).

4. Rotation of the bezel 3 continues until the bezel 3 stop surface L touches the outer cylinder stop surface H (Figure 2).

It will be appreciated that the O-ring D is crushed during rotation of the bezel C (that is, during the assembly of the joint) between the compression surface J of the bezel C and the compression surface G of the outer cylinder B, and is forced to occupy a compression proportional to the dual groove (one groove being the groove E, and the other groove being formed between parts J and B) formed from the inner cylinder A, outer cylinder B and bezel C matched to the dimensions of the four components and the material properties of the O- ring D. The nature of the compression also results in an opposing force against the bezel C, and thus into the screw threading between the bezel C and the outer cylinder B. This inhibits the bezel C from loosening from the outer cylinder B without the need to provide a spring loading mechanism.

The assembled joint has a locking force proportional to the dimensions and the material properties of the four components. The assembled joint may also provide a seal at the interface of the four components proportional to rigidity of the mechanical mounting described above and the predicable deformation of the O-Ring. The mechanical stresses at the O-Ring contacting surfaces and acting on the O-Ring are proportional to the mechanical properties of the joint and usage (for example as a barrier between a fluid and vacuum).

Referring next to Figure 3, a cross sectional view of a related but alternative (due to the "floating" nature of the connection, as will be described below) connector assembly is shown, before engagement of the bezel. An inner cylindrical component 1 , a second component 2 and an O-ring 4 are all visible. In this case the second component (equivalent to the outer cylinder in Figures 1 and 2) is a base part having a channel into which the inner cylinder 1 is slotted. It will be understood that the channel is dimensioned to receive the inner cylindrical component 1. The inner cylindrical component 1 is shown to comprise a groove 5 about its outer circumference, and the O-ring 4 is seated within the groove 5. The cross-sectional diameter of the O-ring 4 can be seen to be approximately equal to the width (vertical distance in Figure 3) of the groove 5, but greater than the depth (horizontal distance in Figure 3) of the groove, with the result that the O-ring extends out beyond the outer surface of the cylinder 1. In this case the depth of the groove 5 is shown to be approximately half of the cross sectional diameter of the O-ring 4, with the result that half of the O-ring 4 is contained within the groove 5, and half of the O-ring 4 is outside of the groove 5. An outer wall of the channel in the base part 2 extends vertically upwards from a floor 12 of the channel to a step 8, shown here to be at the same level as the lower side wall of the groove 5 of the inner cylinder 1. It can be seen from Figure 3 that the inner cylinder 1 does not extend all the way down to the floor 12 of the channel in the base part 2, but instead is suspended with its end face/edge 19 some distance above the floor 12 of the channel due to the fact that the O-ring 4, held in the groove 5, is resting on the step 8, which prevents the inner cylindrical component 1 from dropping down further into the channel. As a result, the relative positioning of the cylinder 1 with respect to the base part 2 is defined not by the position of the floor 12 of the channel, but instead by the position of the groove 5 on the cylinder 1. It will be understood that in this embodiment the only fixed connection between the cylinder 1 and the base part 2 is via the O-ring 4. In other words, the cylinder 1 "floats" with respect to the base part 2. This is beneficial because the cylinder position can be very accurately specified by setting the groove location, and additionally the fact that the linkage between the cylinder and the base part 2 is via a resiliently deformable (e.g. rubber or elastomer) component, a certain degree of shock and stress absorption is built into the design, limiting the amount of mechanical stress experienced by the (potentially fragile) cylinder. From the outer edge of the step 8, an angled surface 7 extends generally upwards at an angle of approximately 45°. This surface 7 forms a compression surface, which is substantially tangential, or at least angled, to the surface of the O-ring. The angled surface 7 leads to a surface 6 which is substantially parallel to the axis of the outer cylindrical component 2, and which leads to a stop surface 9 which takes the form (in this case) of a horizontal seat.

Referring to Figure 4, a cross sectional view of the connector assembly of Figure 3 following engagement of a bezel 3 is shown. The bezel 3 has been engaged (in a similar manner to Figure 2 - for example using complementary screw- threaded formations on the bezel 3 and base part 2) with the base part 2, and is shown to comprise about its circumference a stop surface 10 which is resting upon the stop surface 9. As a result, Figure 4 represents full locking engagement between the bezel 3 and the base part 2, because the bezel 3 is inhibited from moving further towards the base part 2 by the stop surface 9 and the stop surface 10. It is desirable that a structure be provided to define a fully engaged position, since it is at this position that the compression of the O-ring is such as to lock the various parts of the assembly firmly together without damage to the O-ring. Further tightening of the bezel 3 may not only compress the O-ring 4 beyond its capability to spring back into shape, but may also cause the 90° edges at the seams between the cylinder 1 and base part 2 to come out of alignment and cut into the O-ring 4. It can be seen from Figure 4 that except for the engagement between the stop surface 9 and the stop surface 10, a gap is provided between the bezel 3 and the base part 2. The reason for this is that, while in principle the bezel 3 and base part 2 could be formed so that the locking position is achieved when these parts are brought fully into engagement (with no gaps between), in practice it is difficult to guarantee this full surface engagement due to problems with manufacturing tolerances and the likelihood of debris becoming trapped between the bezel 3 and base part 2. The bezel 3 further comprises a compression surface 11 which is at substantially 90° to the angled surface 7 on the base part. The compression surface 1 1 , like the surface 7, is tangential to the surface of the O-ring when the O-ring 4 is uncompressed. The compression surface 1 1 extends from an innermost part of the bezel 3, forming a seam with the outside surface of the cylinder 3 (and in particular, in its engaged state, with the 90° corner between the upper wall of the groove 5 and the outside surface of the cylinder 1). The compression surface 1 1 extends to a point, and when fully engaged overlaps with the stop 9 and wall 6 of the base part 2. The compression surface 1 1 of the bezel 3 is shown in contact with the O- ring 4 thereby compressing the O-ring 4 against the step 8 and tapered surface 7 of the base part 2 and into the groove 5 of the inner cylindrical component 1. The engagement between the stop surface 10 and the stop surface 9 is shown to prevent further compression of the O- ring 4 and to ensure that the compression surface 1 1 is prevented from coming into contact with the compression surface 7. While in the present example the compression surfaces 7 and 11 are shown to be flat, in other examples one or both of them may be curved to accommodate the curved outer surface of the O-ring. In the locked state (where the elements 9 and 10 and in contact), the surfaces 7 and 1 1 may effectively be substantially symmetrical about the centre line of the groove, which may assist in urging the material of the O-ring 4 evenly into the groove.

Referring to Figure 5, a 2D view of the cross section shown in Figure 4 is shown. The O-ring 4 is shown compressed into the space formed between the bezel 3, the step 8 and tapered surface 7 of the outer cylindrical component 2 and the groove 5 of the inner cylindrical component 1. More particularly, it can be seen that compression of the O-ring 4 deforms the O-ring within the groove 5, increasing the proportion of the volume of the O-ring 4 which is contained within the groove 5, and deforms also the parts of the O-ring outside of the groove 5. While bringing the bezel 3 into engagement with the base part 2 could be expected to compress the O-ring only in the direction of movement between these two parts, in practice the tangential angles of the compression surfaces 7, 1 1 cause these surfaces to compress the O-ring in a direction generally towards and into the groove 5. In addition to providing for mechanical engagement, in some embodiments the compressed O-ring may form a seal between the inner cylindrical component 1 and the base part 2, which may prevent ingress or egress of fluids (for example) through the joint. Due to the fact that the inner cylindrical component 1 and the base part 2 are engaged via the ring, rotational movement of the cylindrical component 1 with the base part 2 is also inhibited. It will be appreciated that while the contact area between the ring and each of the cylindrical component 1 , base part 2 and bezel 3 is relatively small at any given position around the circumference of the cylindrical component 1 , the locking force is relatively strong since the contact area preferably extends around the full circumference of the cylindrical component 1 , giving a relatively large contact area overall.

Referring to Figure 6, a 3D view of a container/housing implementation of the connector assembly described above is provided comprising a transparent cylindrical component 1 connected to a base 18 and a lid 13. The base 18 can be seen to comprise a bottom part 18a, a first outer cylindrical component 2, and a first bezel 3. The lid 13 can be seen to comprise a top part 13a and a second bezel 14. In effect, the connector assembly described previously is applied here to both ends of the cylinder 1. The resulting structure could be a housing for a device, or could be a container. Due to the nature of the connector assembly (which may provide a weatherproof seal), embodiments of the present invention may be especially well-suited for use as part of a weatherproof housing.

Figure 7 is an exploded view of the container/housing of Figure 6. Starting from the bottom of Figure 7, the base 18 can be seen to comprise a bottom part 18a, onto which is mounted an annular component 2 having a circular channel for receiving the circular bottom edge of the transparent cylinder 1 , and having a compression surface for compressing an O- ring 4a, which upon assembly will be placed in a groove 5a extending around the outside circumference of the cylinder 1. Above this is a first bezel 3a, which extends around the cylinder 1. Together, these elements carry the groove 5a (on the cylinder 1), the

compression surfaces (on the end part 2 and bezel 3a), and function together with the O-ring 4a to mount the base to the cylinder in a robust and (optionally) sealed manner. Similarly, starting from the top of Figure 7, the lid 13 can be seen to comprise a top part 13a, to the underside of which is mounted a cover 16. The top part 13a carries a circular channel for receiving the circular top edge of the transparent cylinder 1 , and also has a compression surface for compressing an O-ring 4b, which upon assembly will be placed in a groove 5b extending around the outside circumference of the cylinder 1. Below the O-ring 4b is shown a second bezel 3b, which extends around the cylinder 1. Together, these elements carry the groove 5b (on the cylinder 1), the compression surfaces (on the lid 13 and bezel 3b), and function together with the O-ring 4b to mount the lid to the cylinder in a robust and

(optionally) sealed manner.

Figures 8A and 8B schematically illustrate an alternative geometry for the groove E, first engagement surface F, G and second engagement surface J of Figures 1 and 2. Figure 8A shows the connector assembly in an open position, while Figure 8B shows the connector assembly in a closed position. As with the previous examples, the ring is of circular cross section. However, in this example, the inside of the groove E has a concave shape which conforms to the cross sectional shape of the part of the ring D located within the groove E. Similarly, the first engagement surface F, G (in this case the parts F and G both define engagement surfaces) and second engagement surface J have convex shapes which, together, substantially conform to the cross sectional shape of the part of the D ring which projects outside of the groove E. In this example the groove E and first and second engagement surfaces G and J trap the ring D in place, preferably leaving little or no free space around the ring D, and providing sufficiently close engagement between these surfaces and the ring D to prevent or at least inhibit the ring D moving about within the area enclosed by the groove E, the first engagement surface F, G and the second engagement surface J. However, the surfaces E, F, G and J may not necessarily subject the ring D to significant compression and/or deformation.

As an example, the geometry shown in Figures 8A and 8B may be used in combination with a hard ring, for example of metal wire. In this case, the wire is a relatively incompressible malleable material (e.g. copper, aluminium, nylon, polyethylene) or preformed spring (steel, stainless steel, brass, etc.,) of length equal to outer circumference of inner cylinder. The faces E, F, G, and J are machined with close tolerances to the outer diameter of the wire. The cross section of the wire is intended to be a close match in shape and dimensions to the cross section of the void formed when the surfaces E, F, G and J are in the 'closed' position. While a circular cross section is most likely to be used, a rectangular cross sectional strip would also function. Generally, the outer surface of the wire will be gripped all round by the surfaces E, F, G and J. In some implementations the wire will be crushed (subject to plastic deformation) when the surfaces E, F, G and J are in the closed position, potentially making the connection permanent rather than reversible.

Figures 9A and 9B schematically illustrate an alternative geometry for the groove E, step F, first engagement surface G and second engagement surface J of Figures 1 and 2. Figure 9A shows the connector assembly in an open position, while Figure 9B shows the connector assembly in a closed position. Unlike the previous examples, the ring is of rectangular (in this case square) cross section. In this example, the inside of the groove E has a square concave shape which conforms to the cross sectional shape of the part of the ring D located within the groove E. Similarly, the step F and first engagement surface G are shaped to conform to part of the cross sectional shape of the ring D projecting out of the groove E. More specifically, the step F defines a continuation of the lower side wall of the groove E, and meets the first engagement surface G at a right angle, to accommodate one of the corners of the square cross section of the ring D. In contrast, the second engagement surface J is not shaped to conform to the square cross section of the ring D, but instead is at an angle (as can be seen in Figure 9A). In Figure 9B, it can be seen that as the second engagement surface J comes into contact with the square corner of the ring D, it will crush the corner, which will cause the ring D to be displaced into the groove E and down against the step F. It will be appreciated that by crushing the square corner of the ring D, the ring D will generally expand against the inside of the groove E, and against the step F and first engagement surface G. As a result, the ring D fits tightly within the volume bounded by the surfaces E, F, G and J when the connector assembly is in its closed position. As a result, the cylinder part A and outer part B are connected firmly together by the ring D. It will be appreciated that in this example the surfaces E, F, G and J subject the ring D to significant compression and/or deformation.

Figures 10A and 10B schematically illustrate an alternative geometry for the groove E, step F, first engagement surface G and second engagement surface J of Figures 1 and 2. Figure 10A shows the connector assembly in an open position, while Figure 10B shows the connector assembly in a closed position. Unlike the previous examples, the ring is of hexagonal cross section (although other regular polygons, irregular polygons, or irregular shapes in general could also be used). In this example, the inside of the groove E has a concave shape which conforms to the cross sectional shape of the part of the ring D located within the groove E. Similarly, the step F and first engagement surface G are shaped to conform to part of the cross sectional shape of the ring D projecting out of the groove E. More specifically, the step F defines a continuation of the lower side wall of the groove E, and meets the first engagement surface G at an angle of 120°, to accommodate one of the corners of the hexagonal cross section of the ring D. In contrast, the second engagement surface J is not shaped to conform to the hexagonal cross section of the ring D, but instead is at an angle (as can be seen in Figure 10A). In Figure 10B, it can be seen that as the second engagement surface J comes into contact with the exposed corner of the ring D, it will crush the corner (and the adjacent sides), which will cause the ring D to be displaced into the groove E and down against the step F. It will be appreciated that by crushing the corner of the ring D, the ring D will generally expand against the inside of the groove E, and against the step F and first engagement surface G. As a result, the ring D fits tightly within the volume bounded by the surfaces E, F, G and J when the connector assembly is in its closed position. As a result, the cylinder part A and outer part B are connected firmly together by the ring D. It will be appreciated that in this example the surfaces E, F, G and J subject the ring D to significant compression and/or deformation.

As an example, the geometries shown in Figures 1 , 2, 9A, 9B, 10A and 10B may be used with a soft ring. The rings may be moulded, or extruded, stamped or otherwise formed, and be of a length sufficient to stretch over the outer diameter of the inner cylinder in order to be installed in the groove E and recover tension. When compressed, the ring deforms in such a way as to convert compressive forces exerted by faces J and G into pressure on the face(s) of groove E. Compressible materials such as rubber, butyl, nitrile, or silicone exhibit suitable properties for this purpose.