The present invention relates to a connection arrangement for coupling objects together, and in particular relates to a connection arrangement for the coupling of a male and female component by means of a snap fit type action. BACKGROUND TO THE INVENTION

There are many forms of connection arrangements for the coupling of male and female components by means of a snap fit action. Such connection arrangements comprise one or more connecting elements such as lugs or projections on one component which engage upon or with the other component.

Such connection arrangements rely upon deformation of the connecting elements during the coupling process, or alternatively upon radial movement of the connecting elements during the coupling process. However, whilst such connections can provide for the easy coupling of the male and female components, the connections may also prone to being inadvertently uncoupled.

It is therefore an object of the present invention to provide an improved connection arrangement for coupling male and female components which enables the male and female components to be easily coupled by means of a snap fit action and which also safeguards against the components being inadvertently uncoupled.

SUMMARY OF THE INVENTION

To this end the present invention provides a connection arrangement for coupling a male and a female component, said connection arrangement including: a means for locating the female component with respect to the male component; a locking means for coupling the female component to the male component; wherein said locking means is adapted to rotate with respect to the locating means during the coupling and uncoupling of the components.

Advantageously the present invention provides a connection arrangement which does not rely upon distortion or radial movement of the

locking elements during either coupling or uncoupling of the male and female components.

This form of connection arrangement can provide for the easy coupling of two objects whilst also safeguarding against the inadvertent separation of the objects when coupled together. Furthermore, one preferred form of the present invention provides for the permanent connection of the male and female components so as to prevent uncoupling of the components. An alternative preferred form of the present invention provides for the connection of the male and female components which is lockable but which can be released to provide for uncoupling of the components. A further preferred form of the invention provides for the connection of the male and female components which can be released by a pulling action in order to uncouple of components.

Preferably the male and female components are connected along an axis and said locking means is adapted to rotate in a plane perpendicular to said axis. It is further preferable that said locking means is adapted to rotate about said axis.

Preferably locking means are provided on the male component which cooperate with locking means on the female component.

It is further preferable that the means for locating the female component with respect to the male component comprises one or more projections or grooves on the female component which cooperate with one or more corresponding projections or grooves on the male component.

In one preferred form of the invention the female member is provided with an annular skirt or ring upon the inner surface of which are provided said locking elements in the form of grooves and/or projections. The skirt or ring is designed so as to prevent radial movement of the locking elements.

Preferably the male member is provided with a cylindrical outer surface over which the female member is to be located, the cylindrical outer surface of the male member being provided locking means in the form of grooves and/or projections, said grooves and/or projections on the female member and the male member being adapted to cooperate such that the female member is fitted to the male member by a snap fit action.

BRIEF DESCRIPTION OF DRAWINGS

Reference is made to the accompanying drawings in which:

Fig. 1 is a sectional side view of a preferred embodiment of the connection mechanism of the present invention, comprising a female coupling member, a corresponding male coupling member, and an additional locking device.

Fig. 2 is a sectional side view of a female member coupled to a male member by means of one preferred embodiment of the connection mechanism of the present invention. Fig. 3 is a sectional side view of a female member coupled to a male member by means of an alternative preferred embodiment of the connection mechanism of the present invention.

Fig. 4 is a sectional axial view of the connection arrangement taken along line "D" in Fig. 1 ; Fig. 5 is a sectional axial view of the connection arrangement taken along line "C" in Fig. 1 ;

Figs. 6a, 6b, 6c are sectional views along line "B" in Fig. 1 and illustrate one embodiment of the locking mechanism according to the present invention.

Figs. 7a, 7b, 7c are sectional views corresponding to Figs. 6a, 6b, 6c which illustrate an alternative embodiment of the locking mechanism according to the present invention.

Figs. 8a to 8c illustrate one configuration of the locking mechanism according to the present invention.

Figs. 9a to 9c illustrate an alternative configuration of the locking mechanism according to the present invention.

Figs. 10a to 10c illustrate a further alternative configuration of the locking mechanism according to the present invention. DESCRIPTION OF PREFERRED EMBODIMENT

The details of a preferred embodiment of the connection arrangement will now be described.

Referring to Fig. 1 , the male member 10 includes a cylindrical outer wall 12, the surface of which is provided with locating/guiding means in the form of a

series of projections 16 which are spaced around the outer circumference of the wall so as to define gaps therebetween. In the embodiment depicted in Fig. 1 , the projections 16 are located proximate the outer end 18 of the male member. Whilst the male member 10 depicted in Fig. 1 is hollow, it should be noted that the male member may also be solid in cross section.

The corresponding female member 20 includes a cylindrical inner wall 22, the surface of which is provided with locating/guide means in the form of projections 28 which are located away from the open end or mouth 26 of the female member. In the embodiment depicted the projections 28 extend in an axial direction down the cylindrical inner wall 22 of the female member. As is best illustrated in Fig. 5, a series of projections 28 are located around the cylindrical inner wall of the female member.

Referring to Figs. 1 and 2, a further preferred feature of the present invention is locking member 30. The locking member 30 may be employed in applications where there is a need to ensure positive locking between the male and female members, or where a degree of tamper proofing of the connection is desired. In the preferred embodiment depicted the locking member 30 takes the form of an annular sleeve or collar which is engaged on the female member 20 by means of a lug 36 which is located in a corresponding outer recess or aperture 21 in the wall 22 of the female member 20. In an alternative embodiment the locking member 30 may be engaged with the male member 10. A tab 34 is provided to enable the user to easily manipulate the locking member between its locked and unlocked positions. The locking member 30 includes one or more fingers 32 which are adapted to be located between the male and female members and to restrict the turning movement of the female member relative to the male member and thereby prevent decoupling of the members. The positioning of the finger 32 when in the locked position is illustrated in Figs. 2 and 4.

As shown in Figs. 2 and 3 the male and female members are connected along an axis.

Upon fitting the female member 20 to the male member 10 the projections 28 on the inner surface of the female member pass neatly through the gaps

defined by the projections 16a, 16b on the outer wall of the male member, as illustrated in Figs. 2 and 5.

It should be appreciated that the inverse arrangement is possible, namely two projections defining a gap therebetween can be provided on the inside surface of the female member whilst a cooperating projection is provided on the outer surface of male member. Alternatively, rather than using projections the same function could be achieved by providing appropriately located grooves in the outer surface of the male member and/or the inner surface of the female member. Referring to Fig. 1 , cooperating locking means in the form of projections or lugs 14, 24 are provided on the outer surface of the male member and the inner surface of the female member respectively. One or more locking lugs 24 are provided on the inside surface of the skirt of the female member at a location proximate the mouth 26 of the female member. Similarly, one or more locking lugs 14 are provided on the outside surface of the male member at a location which will result in the respective locking lugs 14, 24 cooperating to restrain the female member on the male member when the female member is fully fitted.

Referring to Fig. 3, an alternative configuration of the guide means and locking means is depicted. In this arrangement the guiding projections 28 on the female member are located proximate the mouth of the female member and the locking lugs 24 are located away from the mouth. Conversely, the locking lugs 14 of the male member are located proximate its end 18 whilst the projections 16 are located away from the end. During the coupling the locking lugs 14 of the male member pass over the locking lugs 24 of the female member. If the torsional rigidity of the side wall 22 of the female member is sufficient, this form of connection will prevent external unlocking of the coupling. This embodiment of the invention may be employed in applications such as the coupling of pipes and the like. In applications where the male and female members are conduits for a fluid, a suitable seal may be incorporated into the coupling to provide for sealing between the male and female members in the zone of the coupling.

Referring to Figs. 6a, 6b, and 6c the operation of one set of cooperating guiding and locking projections of the connection mechanism will now be described.

In order to couple the male and female members the guiding projection 28 on the inside surface of the female member is brought into alignment with the gap 23 between the two guiding projections 16a, 16b on the outer surface of the male member. When the projection 28 on the female member is aligned with the gap 23 between the guiding projections 16a, 16b on the male member the locking lug 24 on the female member and the locking lug 14 on the male member are in proximity to each other. In this position the locking lugs 14, 24 are not in direct axial alignment but are slightly offset as illustrated in Fig. 6a.

To fit the female member to the male member a force is applied in the axial direction so as to result in the relative movement of the female member over the male member as indicated by the arrow in Fig. 6a. As the female member moves over the male member the respective outer surfaces 15, 25 of the locking lugs 14, 24 come into contact. The outer surfaces 15, 25 of the locking lugs have a plane of contact which is at an angle relative to the direction in which the force is applied. Further force results in the two surfaces 15, 25 of the locking lugs 14, 24 sliding over each other. This relative movement under the action of the axial force gives rise to rotational movement of the skirt of the female member in a plane perpendicular to the axis of the connection as indicated by the arrows in Fig. 6b, whilst the upper end of the female member is restrained from movement by the location of the projection 28 on the inner surface of female member between the projections 16a, 16b on the outer surface of the male member. In the embodiment depicted in Figs. 6a, 6b, and 6c the rotational movement of the skirt of the female member arises from a degree of distortion (torsion) in the skirt of the female member. The skirt 22 of the female member may be provided with one or more apertures, such as axially extending slots 21 , in order to provide sufficient torsional flexibility in the skirt. Once the surface 25 of the locking lug 24 has passed over the surface 15 of locking lug 14 the torsional stress in the female member is released and the locking lug 24 on the female member will snap back to a position beneath

locking lug 14 on the male member. When fitted, locking of the female member on the male member is provided by the location of the lug 24 of the female member in relation to the lug 14 on the male member as illustrated in Fig. 6c.

In the embodiment depicted by Figs. 6a, 6b and 6c when the female member is coupled to the male member the application of a direct axial force to pull the female member away from the male member will not uncouple the female member from the male member. The skirt of the female member is designed so as to ensure that the locking lugs 14, 24 cannot disengage radially. Therefore in order to remove the female member from the male member it is necessary to apply a twisting (torsional) force to the skirt of the female member in order to move locking lug 24 laterally relative to locking lug 14 so as to clear the lower surface 17 of locking lug 14. Once clear, the application of an axial force will result in removal of the female member from the male member.

In an alternative form of the invention the skirt of the female member may be of sufficient torsional rigidity so that during the coupling process there is no rotational movement of the portion of the female member carrying the locking lugs 24. In this embodiment the rotational movement is provided by torsional flexure in the male member such that the portion of the male member carrying the locking lugs 14 undergoes rotational movement during coupling. In a further alternative embodiment, both the male and female members may be provided with a degree torsional flexure such that the portions of both the male and female members which carry the locking lugs 14 and 24 respectively undergo rotational movement during the coupling process.

Figs. 7a, 7b, and 7c illustrate the operation of another alternative embodiment of the connection mechanism, wherein rather than relying upon flexure in the skirt of the female member, a mechanical biasing arrangement is employed. In this embodiment the portion the female member which carries the locking lug 24 is separate from that portion of the female member which carries the guiding projection 28 and can rotate with respect thereto. A biasing means, such as one or more springs, act between the two portions of the female member.

In this embodiment, as the female member moves over the male member the respective outer surfaces 15, 25 of the locking lugs 14, 24 come into contact. The outer surfaces 15, 25 of the locking lugs have a plane of contact which is at an angle relative to the direction in which the force is applied. Further force results in the two surfaces 15, 25 of the locking lugs 14, 24 sliding over each other. This relative movement under the action of the axial force gives rise to rotational movement of the skirt of the female member as indicated by the arrows in Fig. 7b whilst the upper end of the female member is restrained from movement by the location of the projection 28 on the inner surface of female member between the projections 16a, 16b on the outer surface of the male member. In the embodiment depicted in Figs. 7a, 7b, and 7c the rotational movement of the skirt of the female member arises from the rotation of the skirt of the female member against the action of the spring.

Once the surface 25 of the locking lug 24 has passed over the surface 15 of locking lug 14 the spring acts to rotate the skirt such that the locking lug 24 on the female member moves back to a position beneath locking lug 14 on the male member. When fitted, locking of the female member on the male member is provided by the location of the lug 24 of the female member beneath the lug 14 on the male member as illustrated in Fig. 7c. Similarly, an alternative embodiment of this form of the invention is to provide the locking lugs of the male member on a biased, rotatable portion such as a ring. A further possible alternative is to provide both the male and female members with biased rotatable rings upon which the respective cooperative locking lugs are provided. Referring to Figs. 8a to 8c, 9a to 9c, and 10a to 10c it is possible to vary the degree of force required to in order to couple the male and female members and to also vary the degree of locking provided by the mechanism once the male and female members have been coupled. As described, during coupling of the female member to the male member the outer surfaces 15, 25 of the locking lugs 14, 24 have a plane of contact which is at an angle relative to the direction of relative movement of the male and female members. By varying the angle of the plane of contact the degree of force required to couple the members can be

varied. This may also be varied by varying the sizing of the lugs and also by varying the axial offset of the lugs.

Furthermore, when the locking lugs 14, 24 are in the locked position the surfaces 17, 27 of the lugs have a plane of contact 40. The angle between the plane of contact 40 of the locking lugs and the axial plane of the connection of the male and female members, α, influences the locking action of the lugs 14,

24. For example, by varying the angle α it is possible to provide an arrangement wherein there is a degree of "self locking" between the locking lugs 14, 24. That is, the locking lugs will tend to move to relative positions which provides a greater degree of locking.

It should also be noted that the angle between the plane of contact 40 of the locking lugs and the axial plane of the male and female members influences the amount of force required to uncouple the members. In the embodiments depicted the angle α represents the angle between the plane of contact of the locking lugs and a plane orthogonal to the axial plane of the male and female members. Thus, in the embodiment depicted in Figs. 10a to 10c where angle α is larger than for the embodiment depicted in Figs. 9a to 9c, the force required to uncouple the members is less. Thus by varying the angle α it is possible to design a coupling which can be uncoupled by the application of an axial force without the need for the user to also provide an additional external twisting

(torsional) force to the male or female component.

The present invention can be used in numerous applications. For example, it may be utilised as a coupling mechanism for conduits such as hoses, pipes and the like, or for connecting cables. It may also be used as a closure arrangement for containers and the like.