WO2012153086A1

WO2012153086A1 - Connector for component connection in a modular construction set

Info

Publication number: WO2012153086A1
Application number: PCT/GB2012/000416
Authority: WO
Inventors: Philip Ross NORMAN
Original assignee: Robosynthesis Limited
Priority date: 2011-05-06
Filing date: 2012-05-04
Publication date: 2012-11-15
Also published as: GB2490551B; GB2490551A; GB201107623D0

Abstract

A connector (10) for component connection in a modular construction set comprises a hollow drum portion (11) and a flange portion (12) extending from the circumference of the drum portion, the drum portion having a plurality of equidistantly spaced apertures (14) around its circumference and the connector being provided on the drum portion with a captive locking ring (22) having a respective locking projection (24) extending through each of the apertures and into the interior of the drum portion. The locking ring (22) is rotatable relative to the drum portion (11) between an unlocking position in which at least one of the locking projections (24) is substantially alignable at its underside with a surface of a component, for example an adapter (30), received in the drum portion (11) and a locking position in which that projection is engageable, especially pressurably engageable, with the surface of the component (30) for retention of the component in the drum portion.

Description

CONNECTOR FOR COMPONENT CONNECTION IN A MODULAR CONSTRUCTION

SET

The present invention relates to a connector for component connection in a modular construction set.

Construction sets are known in various forms for constructing assemblies or subassemblies in which the constituent parts have differing angular and rotational relationships so as to form complex modular structures in two and three dimensions. Such assemblies or subassemblies can be, for example, essentially static constructions such as models, support structures and mounts or movable or mobile constructions such as robotic assembly and fabrication tools or self-propelled robots for various purposes. A construction set focussed on allowing creation of assemblies and subassemblies with such capabilities is disclosed in International Patent Specification WO 2008ιΌ93028. A principal component of the set disclosed in this specification is a connector which has a drum or cylinder portion and a flange portion at its circumference, the drum portion having transverse grooves at its free end or, if it extends on either side of the flange portion, its free ends. These grooves each serve to receive an edge region of the flange portion of another such connector so that the connectors can be connected together in an orthogonal relationship. Another component of the set is an adapter, which can be inserted into juxtaposed drum portions of two coaxial connectors to connect the connectors together in coaxial relationship. The adapter can be secured in position by locking members which embrace the drum portion of each connector and project, by locking projections, into the interior of the drum portion. The locking projections cooperate with the adapter to prevent removal. The locking members, which can take various forms, are generally arcuate in shape and can be used individually in some applications or combined in other applications, especially to fix an adapter to a connector, to form a complete ring.

An advantage of securing by way of locking members of that kind is that the members can be placed in position, thus applied to the drum portion of a connector, from outside and after an assembly of connectors and adapter has been created. Equally, the members can be removed for the purpose of disassembly of these components. Conversely, a disadvantage is that the part count of the set is necessarily increased and there is a greater number of small, loose parts to be transported, stored and fitted as well as potentially mislaid.

The invention therefore has as its principal object the incorporation of an integrated locking system in a connector serving for component connection in a construction set, particularly a connector which can be coupled with an adapter of the kind previously described or another type of component, whereby part numbers required in a set may be reduced and a locking facility is constantly available at the connector itself.

Other objects and advantages of the invention will be apparent from the following description.

According to a first aspect of the present invention there is provided a connector for component connection in a modular construction set, the connector having a hollow drum portion and a flange portion extending from the circumference thereof, the drum portion having a plurality of apertures around its circumference and the connector being provided on the drum portion with a captive locking ring having a respective locking projection extending through each of the apertures and into the interior of the drum portion, the locking ring being rotatable relative to the drum portion through a limited range of rotation between an unlocking position in which at least one of the projections is substantially alignable at a side thereof facing the flange portion with a surface of a component received in the interior of the drum portion and a locking position in which the at least one projection is engageable with the surface of the component for retention of the component in the drum portion.

Such a connector has an integrated locking system represented by the captive locking ring, which constitutes part of the connector and does not require collection of an appropriate number of individual separate locking members and fitting of members to the connector in order to fix a component connected to the connector. The locking ring has, by virtue of its annular form, a substantial degree of rigidity and thus strength and is particularly simple to actuate for locking and unlocking purposes, namely by rotation relative to the drum portion. The more laborious process required to assemble locking members on the drum portion to form a ring or part of a ring is obviated. Moreover, apart from the integrated locking ring and appropriate adaptation of, inter alia, the aperture geometry for the locking projections, the connector can be of fundamentally the same construction as the connector of the known construction set, so that commonality of production tools and co-operation with other known set components are possible.

The apertures are preferably equidistantly spaced, so that the component retention forces can be uniformly distributed, and for preference four such apertures are present. Four apertures and consequently four locking projections at the locking ring provide very stable engagement with the surface of the component to be retained, thus resistance to tipping. The provision of four locking projections can be linked with other constructional features, which can also be four in number and in correlated angular positions of the connector as described further below. In addition, the provision of four locking projections provides a good compromise between retention capability and the level of friction which is generated at the projections and opposes rotation of the ring.

For preference, each aperture has a greater dimension in the circumferential direction of the drum portion than the respective projection extending therethrough and the relative rotation of the locking ring and the drum portion is limited by mutually opposite boundaries of at least one of the apertures. The rotational capability of the locking ring, in particular its range of rotation between the unlocking and locking positions, is thus determined in simple manner by the aperture itself without the need for other abutments or stops. The flexibility of the locking ring can be enhanced if it is rotatable relative to the drum portion from the unlocking position to the locking position in each of two mutually opposite directions of rotation, the ring thus having a bidirectional rotational capability so that it can be brought into action in either one of two directions of rotation according to the wish of the user or other considerations applicable to an assembly incorporating the connector.

The locking ring is preferably rotatable relative to the drum portion from the unlocking position to the locking position against an initially increasing and then progressively decreasing force. The ring is therefore brought into action by initial application of a driving force sufficient to overcome a resistance, in particular a resistance to departure of the ring from the unlocking position in which it normally resides. The resistance to rotation thereafter reduces so that the ring tends to locate in its locking position when that position is reached and will not, by itself, return to the unlocking position.

For preference, at least one of the flange portion, drum portion and locking ring comprises material capable of yielding and the increasing and decreasing force is provided by deflection and return, or compression and decompression, of the material in conjunction with limited axial displacement of the locking ring relative to the drum and flange portions. The constituent material of at least one of the parts of the connector can thus be exploited, in conjunction with limited axial displacement of the locking ring relative to the rest of the connector, particularly a displacement arising through the taking up of tolerances of the ring, to supply the force resisting ring rotation. The material can accordingly exhibit a restricted level of resilience.

Operation of the locking ring may be enhanced in the case of a construction in which the ring is provided at a side thereof towards the flange portion with protrusions engageable in recesses in a face of the flange portion in the unlocking position of the locking ring thereby to define the unlocking position, the increasing force being generated by movement of the protrusions out of the recesses and into pressurable contact with the face of the flange portion under axial displacement of the locking ring relative to the flange and drum portions when the locking ring is rotated out of the unlocking position. The protrusions are, in effect, lifted out of the recesses when the ring is rotated, so as to bring each protrusion into contact with the junction of a side wall of the associated recess and the adjoining face of the flange portion, the junctions acting as cams and co-operating with surfaces of the protrusions which are preferably curved. Movement of the protrusions out of the recesses takes place, under axial displacement of the locking ring, against a force produced by deflection/compression of the locking projections or of co-operating parts of the drum portion. This results from, for example, each of the locking projections being brought into pressurable contact at a side thereof remote from the flange portion with a boundary of the associated aperture during movement of the locking ring out of the unlocking position, the boundary being shaped so that the contact pressure is at a maximum immediately after movement of the locking ring out of the unlocking position and reduces until at a minimum in the locking position of the ring thereby to provide the progressively decreasing force. In that case, the shaped boundary can be convex so that with respect to the circumferential direction of the drum portion the aperture widens in directions away from a central region. Each locking projection can have a curved surface which, in conjunction with the mentioned convex shape of the aperture boundary, results in a substantially lineal contact so as to minimise friction during rotation of the locking ring.

It is envisaged that rotation of the locking ring will normally be performed manually, in which case the ring is preferably provided with drive application surfaces, for example grip protrusions at the outer circumference of the ring, engageable for application of a driving force to rotate the locking ring relative to the drum portion. Depending on the force required for rotation of the ring, ease of access in an assembly and purchase offered by the grip protrusions or similar, rotation can also be by way of a suitable lever tool engaging the drive application surfaces.

For preference, the drum portion has at least one detent element detentable with a component received in the interior of the drum portion to prevent rotation of the component relative to the connector. In that case, a plurality of such detent elements is preferably provided, each element being aligned with a respective one of the locking projections of the locking ring in the unlocking position thereof. These detent elements can conveniently comprise webs each engageable in a respective recess in the component, in which case, having regard to known connector features which can advantageously be duplicated in the connector of the present invention so as to allow use in similar manner with other components of known construction sets, the drum portion is preferably provided in its interior with a centring post for centring a component received in the interior and the webs then connect the post with a circumferential wall of the drum portion.

In order to securely locate a component to be connected with the connector the drum portion is preferably provided in the interior thereof with a shoulder for supporting a component received in the interior so that part of the component can be held between the shoulder and the locking projections of the locking ring. The component can thus be firmly clamped between the shoulder and the locking projections, subject, of course, to compatible dimensioning of the component.

With respect to features present in known connectors it is desirable from the aspect of commonality of use and interchangeability with known connectors if in the case of the connector of the present invention the drum portion is provided at a free end thereof with at least one transverse groove for reception of the flange portion of another such connector in orthogonal relationship. It is then advantageous if the drum portion has a plurality of such grooves and the locking projections of the locking ring each extend into a respective one of the transverse grooves, the grooves in that case preferably comprising a first pair of parallel grooves and a second pair of parallel grooves extending perpendicularly to the grooves of the first pair. A subsidiary locking function of the locking ring is then achievable if the flange portion is provided at its circumference with a plurality of radial slots each for reception of a locking projection of the locking ring of another such connector on insertion of the flange portion into a transverse groove of that other connector, in which case the flange portion can be provided on at least one side thereof with an annular channel concentric with the drum portion and communicating with the radial slots so that a locking projection of the other connector received in one of the slots is engageable in the annular channel on relative rotation of the connectors. Locking of two connectors orthogonally coupled in this manner is then provided not only by rotation of the locking ring, but by relative rotation of the connectors about axes of their respective drum portions, these axes being orthogonal.

The drum portion of the connector preferably extends on either side of the flange portion, in which case the option arises of providing the locking ring only on one side of the flange portion. For preference, however, the drum portion has a respective plurality of apertures on either side of the flange portion and the connector is provided with a respective such captive locking ring on each side of the flange portion, the locking projections of each locking ring extending through the apertures of the plurality at that side of the flange portion. The connector can thus be employed for component connection on both sides of the flange portion and the possibility is thereby created of utilising a number of such connectors to produce an axial assembly of any selected length.

In order to achieve captivity of the locking ring the connector can be constructed in various ways. In one preferred embodiment, the drum and flange portions are of integral construction and the or each locking ring of multi-part construction. This results in a connector body of substantial strength and allows the possibility of fitting the locking ring to the drum portion after the connector body has been produced. Thus, the or each ring can comprise an annular body and separately constructed locking elements non- detachably attached to the body to provide the locking projections. Since the engagement of the locking projections in the apertures can be the sole means by which the locking ring is kept in place, i.e. made captive, the ring can be simple to fit by placing the annular body around the drum portion and then attaching the separately constructed locking elements to that body. The elements can be fixed by a material bond, such as adhesive or welding, and/or by a mechanically positive coupling. A combination of both may be particularly advantageous. In one convenient construction, the annular body has at the locations of the locking projections waisted portions of reduced thickness in the axial and radial directions of the body and the locking elements are clipped onto the waisted portions. The clipped-on locking elements can thus be largely integrated into the annular body itself, apart from the inwardly directed locking projections. The projections can be provided in simple manner if each of the locking elements comprises a substantially U- shaped clip portion clipped onto a respective one of the waisted portions of the annular body from outside the body, one of the limbs of the U-shape being prolonged to form the respective locking projection. Locking elements of this kind are simple to produce, for example from plastics material by injection moulding, and in conjunction with the waisted portions can be firmly seated at the annular body. A particular firm mechanically positive and non-detachable connection can be achieved if each of the waisted portions and the clip portion of the associated locking element have mutually co-operating surfaces defining a wedge lock preventing unclipping of the element by displacement from inside the annular body.

In another preferred embodiment, the or each locking ring can, by contrast, be of integral construction and the drum and flange portions of multi-part construction. Such a one- piece ring can be stronger and easier to produce, in the respect that assembly steps for construction of the ring are eliminated, but in this case the connector body is created by assembly procedures. For that purpose the drum and flange portions preferably comprise a separately constructed drum body and disc body, the disc body having a central passage and the drum body being engaged in the passage and attached to the disc body. It is then advantageous if the drum and flange portions have co-operating key-and-keyway aligning means to locate the drum and flange portions in a predetermined rotational relationship, which ensures that, for example, the afore-mentioned recesses in a face of the flange portion can be disposed in an intended axial alignment with respectively associated ones of the apertures. If the drum portion extends on either side of the flange it is then desirable to provide two such drum bodies each projecting on a respective side of the disc body, the drum bodies being disposed in end-to-end abutment within the passage of the disc body. As in the case of the first-mentioned constructional embodiment, the or each drum body can be attached to the disc body by at least one of a material bond and a mechanically positive coupling, thus adhesive or welding and/or a bayonet lock or other form of coupling. In order to fit the locking ring, the or each drum body can simply be provided with entry channels permitting movement of the locking projections of the locking ring or associated locking ring from an end of the drum body up to the apertures in an unattached state of the drum and disc bodies, the entry passages being closed in the attached state of the bodies.

Various material can be employed for construction of the connector, for example plastics material for at least the drum and flange portions. These are, with advantage, produced by injection moulding from a polymer material with selected characteristics with respect to, in particular, yield capability. The locking ring can be produced from the same or similar material or, for example, from metallic material.

According to a second aspect of the present invention there is provided a connecting device comprising a connector of the first aspect of the invention and, as component connectible therewith, an adapter for joining the connector to another such connector with the drum portions of the two connectors in substantially coaxial relationship.

Such a connecting device has an enhanced connection capability inasmuch as it represents a set of elements which can be combined with other such sets to form an axial assembly. The adapter in that case preferably comprises an annular body provided with a respective radially outwardly extending flange at each of two opposite ends thereof, the component surface engageable by the locking projections of the or each locking ring of the connector being the inwardly directed face of a selectable one of the flanges of the adapter. The adapter is thus connectible at either end with the connector and can cooperate with further such connectors in the same manner. For preference, the flanges are provided with radially extending slots permitting passage of the locking projections through a selected flange received in the drum portion of the connector to enable alignment of the projections at the sides thereof facing the flange portion of the connector substantially with the inwardly directed face of the selected flange. This represents a simple means of bringing the adapter into a position of readiness for locking in place by the locking ring.

If the drum portion of the connector includes the afore-mentioned shoulder in its interior, the component part to be held between that shoulder and the locking projections of the ring is then represented by a selectable one of the flanges of the adapter, in which case the locking projections are preferably capable of deflection in a direction away from the shoulder by a predetermined amount on movement of the locking ring out of the unlocking position and the axial dimension of the flange of each adapter is greater by substantially that amount than the spacing of the locking projections from the shoulder, so that the projections are pressurably engageable with the inwardly directed face of the selected flange under deflection of the projections. These dimensional relationships ensure that the adapter flange can be pressurably clamped between the shoulder and the locking projections. It can be advantageous in that case if each of the locking projections is provided at the side thereof towards the flange portion of the connector with a chamfer assisting deflection of the projection on transfer from a slot in the selected flange to engagement with the inwardly directed surface of the flange.

Similarly, if the connector has the afore-mentioned detent elements, such as webs, for engagement in recesses in the component to be connected with the connector in order to prevent relative rotation of the connector and component, the recesses can advantageously be provided by the slots in either one of the adapter flanges.

According to a third aspect of the present invention there is provided a connecting device comprising a connector according to the first aspect of the invention, specifically the embodiment thereof with an annular channel in at least one side of the connector flange portion and, as component connectible therewith, an orthogonal coupling member for use in joining the connector to another such connector with the flange portions of the two connectors in substantially orthogonal relationship.

A connecting device of that construction is capable of significantly enhancing the rigidity of the interconnection of two connectors in orthogonal relationship. For this purpose, if the flange portion of each of the connectors is provided with an annular channel on each side thereof the coupling member then preferably comprises locating means engageable in the channel on one side of the flange portion of one of the connectors when a locking projection of the locking ring of the other one of the connectors is engaged in the channel on the other side. Consequently, the flange portion of the said one of the connectors is held at both sides and thus more resistant to tipping relative to the other connector. The locating means preferably has the form of locating tabs extending on an arcuate path, i.e. a path of the same radius as the channel in which they are engaged, so that location is provided over an increased area.

The coupling member preferably comprises fixing means engageable by at least one other locking projection of the locking ring of the other connector thereby to fix the coupling member to that other connector. The feature ensures that the coupling member can be firmly held in place, for which purpose use is advantageously made of the locking ring of the other connector. Rotation of the locking ring from the unlocking to the locking position has the dual effect of securing the coupling member to the other connector and also the two connectors to one another. For preference, the fixing means comprises two oppositely directed fixing lugs each engageable by a respective locking projection of the locking ring of the other connector, whereby the coupling members is anchored at two opposite sides and thus fixed particularly firmly.

As a further feature, the coupling member can comprise positioning wall means engageable with the drum portion of the other connector to lock the coupling member in position relative thereto. Thus ensures firm positional location of the coupling member independently of the locking facility provided by interaction with the locking ring.

Preferred embodiments of the present invention will now be more particularly described by way of example with reference to the accompanying drawings, in which:

Fig. 1 is a perspective view of a connector embodying the invention in conjunction with a component, in particular an adapter, to be connected with the connector, the two forming a connecting device;

Fig. 2 is a plan view of the connector;

Fig. 3 is a side view of the connector with fitted adapter;

Fig. 4 is a perspective view of the connector with fitted adapter locked in place by a locking ring of the connector;

Fig. 5 is a detail view, to enlarged scale, of part of the locking ring in an unlocking position thereof; is a view similar to Fig. 5, but showing the locking ring in a locking position thereof; Fig. 7 is a perspective view of the connector connected with another such connector in mutually orthogonal relationship and with another component, in particular an orthogonal coupling member, which participates in the interconnection of the connectors;

Fig. 8 is a perspective view, inverted in relation to Fig. 7, of the coupling member by itself;

Fig. 9 is a perspective view of part of one form of the locking ring in a state prior to assembly;

Fig. 10 is a view similar to Fig. 9, but after assembly; and

Fig. 1 is an exploded perspective view of a connector incorporating another form of the locking ring.

Referring now to the drawings there is shown a connector 10 intended for component connection in a modular construction set, the purpose of which, such as the construction of assemblies and subassemblies including robots and other mobile or static constructions, has been indicated in the introduction. The connector is intended to be compatible with connectors of known kinds such as disclosed in WO 2008/0932028 and to co-operate not only with those connectors as well as connectors embodying the present invention, but also other types of components, especially an adapter 30 and an orthogonal coupling member 40 of the kinds also shown in the drawings and further components present in the prior art construction set. The combinations of a connector 10 and an adapter 30 or a connector 10 and a coupling member 40 moreover represent connecting devices in accordance with further aspects of the invention.

The connector 10 comprises a hollow cylindrical drum portion 11 and a circular flange 12 extending radially outwardly from the circumference thereof, the drum and flange portions 1 1 and 12 together forming a connector body of integral or multi-part construction as described further below. The drum portion 11 extends on either side of the flange portion 1 1 and is provided at each of its free ends with two pairs of parallel transverse grooves 13, the grooves of each pair extending perpendicularly to those of the respective other pair. The width of each groove 13 substantially corresponds with the thickness or axial length of the flange portion 12, whereby the flange portion of another such connector 10 or a connector of the kind described in WO 2008/093028 is receivable in the groove, preferably by an interference fit providing a frictional couple. Further details with respect to interconnection of connectors in this manner, in particular in a mutually orthogonal relationship, are provided in the earlier specification.

The circumferential wall of the drum portion 11 is additionally intemupted by four equidistantly spaced apertures 1 which each communicate with the interior of the drum portion centrally of a respective one of the transverse grooves 3. The shape and disposition of the grooves 11 and relationship thereto of the apertures 14 are dearly evident from Fig. 1. The apertures 14 are generally rectangular, but with a convex shape at the side remote from the flange portion 12, with the result that each aperture generally widens in the circumferential direction of the drum portion away from its centre.

The drum portion 11 is formed in its interior, in particular at its inner circumference, with a continuous annular shoulder 15 disposed at spacing from the apertures 14 in direction towards the flange portion Ί2. The shoulder 15, which ^s intended_as a counterbearing support for a component, particularly the adapter 30, to be connected with the connector 10, can also be discontinuous or indeed in any form suitable for providing a firm seat for the component in the interior of the drum portion.

Also provided in the interior of the drum portion 11 is a tubular centring post 16 which not only serves to centre the adapter 30, but also includes internal coupling elements (not designated or further described) for the purpose of coupling with other types of components, especially an axial stabilising peg (not shown). The post 16 is connected with the circumferential wall of the drum portion 11 by four equidistantly spaced webs 7 which are each aligned with the centre of a respective one of the apertures 1 and which also have a detenting or locating function relative to the adapter 30 as described further below.

The flange portion 12 of the connector body of the connector 10 is provided around its circumference with a plurality - in this instance eight - of equidistantly spaced radial slots 18, four of which are aligned with the apertures 14 and webs 7. The flange portion 12 is additionally provided, on each of its mutually opposite faces 19, with two concentric circular channels 20. Both channels are visible in Fig. 5, but only the outer channel in Figs. 1 , 2 and 4. The radial slots 18 extend into and communicate with the outer one of the channels 20 and continue as recesses 21 , which are present on both sides of the flange portion - but unlike the slots do not pass through the flange portion - and which extend up to the circumference of the drum portion 11. The slots participate in the process of coupling two connectors in mutually orthogonal relationship as described below.

In addition to the connector body with drum and flange portions 11 and 12 the connector 10 is provided with, as a separately constructed part, a captive locking ring 22 serving for locking the adapter 30 when connected with the connector 0 in a coaxial relationship or for locking another connector and/or the coupling member 40 when connected to the connector 10 in an orthogonal relationship as previously mentioned. The locking ring 22 is mounted on the drum portion 11 to be capable of limited rotation relative thereto and to the flange portion 12 and comprises an annular body 23 with four equidistantly spaced, radially inwardly projecting locking projections 24 each extending through a respective one of the apertures 14 and into the associated transverse groove 13, thus the interior of the drum portion 11 , whereby the ring is held captive on the drum portion. Each of the locking projections 24 is spaced from the shoulder 15 by a given amount substantially corresponding with the thickness of a part of the adapter 40 to be received in the drum portion 11 and held by the locking ring 22.

The locking ring 22 is rotatable between an unlocking position, in which the adapter 30 is freely insertable into and removable from the drum portion 11 , and a locking position in which, for example, the inserted adapter 30 is locked in the drum portion. The unlocking position is shown in Fig. 1 and the locking position in Fig. 4. In the unlocking position, each locking projection 24 is disposed substantially centrally in the respective aperture 14 and in the locking position against either one of the two sides thereof spaced apart in the circumferential direction of the drum portion 11. The ring 22 is thus rotatable in either one of two mutually opposite directions to reach the locking position and the two mentioned spaced-apart sides of the aperture act as stops to limit the ring rotation in these directions.

In the normal course, rotation of the locking ring 22 relative to the drum portion 11 is carried out manually, for which purpose the locking ring is provided with a plurality of axially extending grip protrusions 25 on its outer circumference. Rotation in either sense takes place against a defined force as explained below. In the interests, however, of precisely defining this pressure, the frictional couple of the ring 22 and drum portion 11 is reduced in areas where it is not needed, particularly at the interface of the inner circumference of the ring and the outer circumference of the drum portion. This is achieved, as indicated in Figs. 7 and 8, by providing a step in the inner circumferential surface of the ring to reduce the bearing area of that surface.

The defined force opposing rotation of the locking ring 22 relative to the drum portion 11 comes into play in conjunction with limited axial displacement of the former relative to the latter, which derives from tolerances in the fit of the ring on the drum portion, and limited yielding of the constituent material of the connector components, thus the drum portion 1 1, flange portion 12 and ring 22. These components are preferably injection-moulded from a polymer material with a limited capability of resilient deflection and/or compression. Generation of the force is produced by the interaction of parts of the ring 22 with parts of the drum and flange portions 1 and 12. Specifically, the locking ring 22 is provided at its side facing the flange portion 12 with four equidistantly spaced radially extending protrusions 26 which in the unlocking position of the ring engage in the radially extending recesses 21 continuing from the slots in the flange portion Ί2. This interengagement of the radial protrusions 26 and radial recesses 21 defines the unlocking position of the ring and in the absence of applied pressure keeps the ring at rest in its unlocking position. When the ring 22 is rotated, in either sense of rotation, the radial protrusions 26, which have convexly curved surfaces, come into camming interaction with the junctions of the recesses 21 and the adjoining face 19 of the flange portion 12 and are as a consequence lifted out of the recesses and into sliding contact with the face. During this process, the locking projections 24, which each similarly have a convexly curved surface at the side thereof remote from the flange portion 12, are brought - under slight resilient deflection of the projections - into pressurable contact with the convex boundary sides of the associated apertures 14. As rotation of the locking ring progresses, the initially increasing resistance to rotation briefly produced by the pressurable interengagement of the locking projections 24 and the convex sides of the apertures 14 when the radial protrusions 26 depart from the recesses 21 progressively decreases as the locking projections move into the widening sections of the apertures 14 and largely revert to their undeflected state. This movement is shown in Figs. 5 and 6. The decreasing force consequently acts to urge the locking ring 22 into the locking position, in which it is retained, since reverse rotation towards the unlocking position would be opposed by a progressively increasing force. The mentioned convex curvature of bearing surfaces of the radial protrusions 26 and locking projections 24 has the effect that substantially lineal sliding contact arises with, respectively, the associated face 19 of the flange portion 11 and the convex boundary sides of the apertures. This lineal contact serves to minimise friction couples so that the resistance to rotation is largely defined by characteristics of the constituent material or materials. The locking projections 24 can also be provided with convexly curved surfaces at their sides towards the flange portion 12 so as to minimise friction during sliding contact with a part of a component, such as the adapter 30, being locked in place.

The connector 10, apart from provision of the locking ring 22 and the shape of the apertures 14, can be of substantially the same form as prior art connectors as mentioned beforehand and notwithstanding the changed aperture shape can be capable of use, in the absence of the locking ring, with other forms of locking members as described in the introduction. It is thus possible in the manufacturing stage to produce a single connector body able to be subsequently associated with different locking members, which allows integration of the connector of the present invention in construction sets containing connectors using different locking members. It is also possible- for the- connector of the present invention to have the captive locking ring on only one side of the flange portion, so that a different form of locking member can be used on the other side.

The adapter 30 comprises, as evident from Figs. 1 to 4, an annular body 31 provided at each of its two opposite ends with a respective radially outwardly extending circular flange 32, each of which has a diameter substantially corresponding with the inner diameter of the larger diameter section of the drum portion 11 so that either flange can seat on the shoulder 15 in the interior of the drum portion. In similar manner, the inner diameter of the annular body 31 substantially corresponds with that of the tubular centring post 16 of the drum portion 11 so that the adapter, when inserted into the interior of the drum portion is centred by the post and, in particular, supported against lateral loading relative to the drum portion. The adapter 30 and drum and flange portions 11 , 12 as an assembly thus have substantial axial rigidity.

Each of the flanges 32 of the adapter 30 is formed with a plurality - eight in the illustrated embodiment - of equidistantly spaced radial slots 33 which continue to a limited extent in the annular body 32. The slots allow either flange on entry into the interior of the drum portion to reach the shoulder 15 without obstruction by the locking projections 24, which during this movement pass through four of the slots depending on the angular orientation of the adapter; the provision of eight such slots 33 allows relative angular orientations of the adapter and drum portion 11 in increments of 45°. The axial length of the annular body 31 of the adapter is such that when one of the flanges 32 is seated on the shoulder 15 substantially half of the total axial length of the adapter is contained within the drum portion. The protruding other half, as shown in Fig. 3, is thus available for connection with the drum portion of another such connector. In that case, the then mutually facing drum portions can be in end-to-end abutment so as to impart rigidity to the resulting assembly.

The axial length or thickness of each of the flanges 31 is so correlated with the spacing of the undersides of the locking projections 24 from the shoulder 15 that when one of the flanges 32 is supported on the shoulder the undersides of the locking projections, specifically the crests of the convex form of the undersides, are spaced from the shoulder by such an amount that the undersides are substantially aligned with that face of the flange directed inwardly of the adapter towards the other flange, but are offset slightly towards the shoulder. As a consequence of this geometric relationship, when the locking ring 22 is rotated from its unlocking position so that the radial protrusions 26 thereof rise out of the receiving recesses 21 the locking projections are brought into alignment with the flange face and thereafter - under continuing rotation of the ring - enter into pressurable sliding contact with that face. The locking projections 24 are thus constrained between and in pressurable sliding contact with the convex boundary surfaces of the apertures 14 and the inwardly directed face of the flange 32 so that the flange is firmly clamped between the shoulder 15 and the locking projections 24.

The spacing between the undersides of the locking projections 24 and the tops of the aligned webs 17 is somewhat less than the thickness of the flange 32 so that, subject to a suitable width of the slots 33, the webs are partly engageable in the slots to provide a mechanically positive coupling between the connection and adapter in a rotational sense, whereby the connector and adapter are secured against relative rotation.

Release of the flange from clamping is achieved by reverse rotation of the locking ring 22 from the locking position back to the unlocking position, which takes place, as mentioned, against increasing force until the radial protrusions 26 of the ring drop back into the recesses 21 in the associated face of the flange portion 12. Apart from connection of the connector 10 with the adapter 30 in axial relationship the connector can also be connected to a further such connector or a similarly constructed (but without locking ring) prior art connector in a mutual orthogonal relationship. This is achieved by engagement of part of the flange portion 12 of a first one of the connectors into a selectable one of the transverse grooves 3 of the drum portion 11 of the second connector, the first connector being positioned so that the locking projection 24 extending into that groove can enter one of the radial slots 8 of the first connector. Rotation of the locking ring 22 of the second connector now causes that projection 24 to enter the outer one of the concentric channels in an adjoining face 19 of the flange portion 2 of the first connector. The action of the locking ring 22 is in that case as described in connection with the interaction with the adapter 30, except that the participating locking projection 24 is brought into pressurable engagement and sliding contact with the radially outer wall of the channel. Two connectors interconnected in this manner are shown in Fig. 7.

The orthogonal coupling member 30 additionally shown in Fig. 7 and shown by itself in Fig. 8 can also be used to enhance the rigidity of the described interconnection of two connectors in mutually orthogonal relationship and thus represents a further component able to be connected with the connector 10. The connector 10 and coupling member 40 together form a connecting device. The coupling member 40 in the form shown in Figs. 7 and 8 is, in fact, designed to participate in the interconnection of not just two, but three connectors, wherein two of the connectors are connected in axial relationship, such as by the adapter 30, and those two together are connected to a third connector in orthogonal relationship. Fig. 7 shows only two connectors and it will be evident that a further connector can be connected axially to the upright connector and orthogonally to the other connector in similar manner to the illustrated upright connector.

The coupling member 40 comprises a substantially tubular peg 41 receivable in the centring post 16 of the connector 10. The peg is provided at one end and on two opposite sides with two generally arcuate projections 42, each of which has a plurality of spaced- apart and lateral outwardly protruding tabs 43 for firm sliding engagement in the radially outer channel 20 in one of the faces 19 of the flange portion 12 of a connector 10; this engagement has to take place before the connector 10 concerned is engaged, by its flange, in a transverse groove 13 of the drum portion 11 of another connector and before the peg 41 is inserted into the post 16 of that other connector. The coupling member 40 is additionally provided, at the convex sides of the arcuate projections 42, with two mutually opposite part-cylindrical slotted walls 44 engageable with the outer circumferential surface of a connector post 16 receiving the peg 41 of the coupling member. The two slotted walls 44 carry at the free axial ends thereof remote from the arcuate projections 42 two mutually oppositely directed slotted fixing lugs 45 which when the peg 41 is received in the post are substantially aligned, at a side thereof remote from the flange portion 12 of the connector 10 concerned, with the undersides of two diametrically opposite ones of the locking projections 24 of the locking ring 22. The slots in the lugs 45 allow passage of the locking projections between the lugs during insertion of the peg into the post and subsequently receive two of the webs 17 - in particular those aligned with the respective two projections 24 - to lock the coupling member 40 and connector 10 against relative rotation. The disposition of the coupling member 40 when fitted to a connector 10 is evident in Fig. 7.

As is evident from Fig. 7, when a first connector 10, which is fitted with a coupling member 40 by pre-engagement of the tabs 43 of the latter in a channel 20 at one face 19 of the flange portion 12 of the former, is connected in an appropriate rotational setting with a second connector by simultaneous insertion of part of the flange portion 12 of the first connector into one of the transverse grooves 13 of the second connector and insertion of the peg 41 of the member 40 into the post 16 of the second connector, one of the locking projections 24 of the locking ring 22 of the second connector will be positioned in readiness to engage in a channel 20 at the other face 2 of the first connector and two diametrically opposite other ones of the locking projections 24 of the same ring will be positioned in readiness to engage the slotted fixing lugs 45 of the coupling member 40. On rotation of the locking ring 22 of the second connector relative to the drum portion 11 thereof from the unlocking to the locking position the three mentioned locking projections are brought into pressurable engagement with the respectively co-operating surfaces of the first connector and the coupling member, whereby the two connectors 10 will be locked together in mutually orthogonal relationship with stabilisation by the coupling member 40.

The connector 10 itself can be constructed in various ways in order to achieve captive location of the locking ring 22 on the drum portion 11. In one example, the drum and flange portions 11 and 12 are of integral construction, such as by injection moulding from plastics material as a unitary item, and the or each locking ring 22 is a separate component of multi-part construction, for example as shown in Figs. 9 and 10. In this instance the locking ring 22 comprises an annular body formed with four equidistantly spaced waisted portions 22a of reduced thickness in both axial and radial directions of the body and a respective locking element 22b clipped onto the body at each of the waisted portions. Each locking element 22b comprises a substantially U-shaped clip portion, one limb of which is prolonged to form a respective one of the locking projections 24. Detenting of the locking elements 22b on the annular body is achieved by shaping of mutually co-operating surfaces of the clip portion of each locking element 22b and the associated waisted portion 22a of the body to define a wedge lock preventing the locking element from being displaced from the body. In particular, the surfaces defining, at opposite sides of the annular body, each waisted portion taper towards one another radially inwardly of the body and the corresponding surfaces of the clip portion of the associated locking element 22b taper in complementary manner. When each locking element 22b is then pushed onto the respective waisted portion 22a of the annular body the limbs of the clip portion spread and then contract again, under snap action, as the clip portion reaches its end position on the waisted portion. The limb, which is not prolonged, of the Olip portion of each locking element 22b has a radiussed edge to facilitate introduction onto the respective waisted portion 22a of the annular body.

Fig. 9 shows a locking element 22b prior to fitting to a waisted portion 22a of the annular body and Fig. 10 the fitted element. The locking elements 22b can be additionally fixed by, for example, an adhesive or ultrasonic welding.

This construction has the advantage that the locking ring 22 can be assembled on the drum portion 1 1 after manufacture of a connector body with integral drum and flange portions, which allows, inter alia, the possibility of leaving the drum portion at one side of the flange portion without a locking ring, for example so that a different form of locking system can be employed. More importantly, the possibility is created of providing an integral construction of the drum and flange portions so as to optimise the strength of this part of the connector.

An alternative construction of the connector is shown in Fig. 11. In this case the locking ring 21 is of integral construction and the connector body of multi-part construction, namely two separate drum bodies 1 1a together forming the drum portion 1 1 and a separate disc body 12a forming the flange portion 2. The disc body 12a has a central passage receiving external annular rebated portions of the drum bodies 11a in end-to-end abutment, the remaining portion of each drum body then projecting on a respective side of the disc body. The passage in the disc body 12a has at least one key which locates in corresponding keyways of the two drum bodies 11a to preclude relative rotation and to define a predetermined angular relationship of the parts so that the recesses 21 of the disc body, thus flange portion 12, will have the requisite alignment with the centres of the apertures 14 of the drum bodies 11a, thus drum portion 11.

In order to captively fit the integral locking ring 22 to the drum portion 11 each drum body 1 1a has an entry channel 11 b communicating with each of the apertures 14 and allowing movement of a respective one of the locking projectors 24 from an end of the drum body up to and through the aperture. Each locking ring 22 is thus pushed onto the respective drum body 11a in this manner and thereafter the two drums bodies fitted into the disc body 12a, which closes the entry channels 11b. The drum bodies 11a and disc body 12a can then be permanently connected together by adhesive, for example in the keyways receiving the keys, ultrasonic welding or any other appropriate method. Alternatively, the drum bodies and disc body can be provided with co-operable coupling means- so that the three parts can be secured to one another by snap-fit clipping, bayonet locking or other suitable fastening means.

In the thus-assembled connector the two locking rings 22 are permanently captive, but capable of the required limited rotation. In this instance it is conveniently possible to construct the locking ring from a different material, for example metallic material, if this should be appropriate.

A connector or connecting device embodying the present invention can be produced comparatively economically and has a high degree of flexibility in the creation, in conjunction with other such connectors or co-operating components, of modular assemblies and subassemblies usable for wide-ranging purposes.

Claims

1 . A connector for component connection in a modular construction set, the connector having a hollow drum portion and a flange portion extending from the circumference thereof, the drum portion having a plurality of apertures around its circumference and the connector being provided on the drum portion with a captive locking ring having a respective locking projection extending through each of the apertures and into the interior of the drum portion, the locking ring being rotatable relative to the drum portion through a limited range of rotation between an unlocking position in which at least one of the projections is substantially alignable at a side thereof facing the flange portion with a surface of a component received in the interior of the drum portion and a locking position in which the at least one projection is engageable with the surface of the component for retention of the component in the drum portion.

2. A connector according to claim 1 , wherein the apertures are equidistantly spaced:

3. A connector according to claim 1 or claim 2, comprising four such apertures.

4. A connector according to any one of the preceding claims, wherein each aperture has a greater dimension in the circumferential direction of the drum portion than the respective projection extending therethrough and the relative rotation of the locking ring and the drum portion is limited by mutually opposite boundaries of at least one of the apertures.

5. A connector according to any one of the preceding claims, wherein the locking ring is rotatable relative to the drum portion from the unlocking position to the locking position in each of two mutually opposite directions of rotation.

6. A connector according to any one of the preceding claims, wherein the locking ring is rotatable relative to the drum portion from the unlocking position to the locking position against an initially increasing and then progressively decreasing force.

7. A connector according to claim 6, wherein at least one of the flange portion, drum portion and locking ring comprises material capable of yielding and the increasing and decreasing force is provided by deflection and return or compression and decompression of the material in conjunction with limited axial displacement of the locking ring relative to the drum and flange portions.

8. A connector according to claim 6 or claim 7, wherein the locking ring is provided at a side thereof towards the flange portion with protrusions engageable in recesses in a face of the flange portion in the unlocking position of the locking ring thereby to define the unlocking position, the increasing force being generated by movement of the protrusions out of the recesses and into pressurable contact with the face of the flange portion under axial displacement of the locking ring relative to the flange and drum portions when the locking ring is rotated out of the unlocking position.

9. A connector according to any one of claims 6 to 8, wherein each of the locking projections is brought into pressurable contact at a side thereof remote from the flange portion with a boundary of the associated aperture during movement of the locking ring out of the unlocking position, the boundary being shaped so that the contact pressure is at a maximum immediately after movement of the locking ring out of the unlocking position and reduces until at a minimum in the locking position of the ring thereby to provide the progressively decreasing force.

10. A connector according to claim 9, wherein the shaped boundary of each aperture is convex so that with respect to the circumferential direction of the drum portion the aperture widens in directions away from a central region.

11. A connector according to claim 9 or claim 10, wherein each locking projection has a curved surface for substantially lineal contact with the shaped boundary of the associated aperture.

12. A connector according to any one of the preceding claims, wherein the locking ring is provided with drive application surfaces engageable for application of a driving force to rotate the locking ring relative to the drum portion.

13. A connector according to claim 12, wherein the drive application surfaces comprise grip protrusions at the outer circumference of the locking ring.

14. A connector according to any one of the preceding claims, wherein the drum portion has at least one detent element detentable with a component received in the interior of the drum portion to prevent rotation of the component relative to the connector.

15. A connector according to claim 14, comprising a plurality of such detent elements each aligned with a respective one of the locking projections of the locking ring in the unlocking position thereof.

16. A connector according to claim 15, wherein each of the detent elements comprises a web engageable in a respective recess in the component.

17. A connector according to claim 16, wherein the drum portion is provided in its interior with a centring post for centring a component received in the interior and the webs connect the post with a circumferential wall of the drum portion.

18. A connector according to any one of the preceding claims, wherein the drum portion is provided in the interior thereof with a shoulder for supporting a component received in the interior so that part of the component can be held between the shoulder and the locking projections of the locking ring.

19. A connector according to any one of the preceding claims, wherein the drum portion is provided at a free end thereof with at least one transverse groove for reception of the flange portion of another such connector in orthogonal relationship.

20. A connector according to claim 19, wherein the drum portion has a plurality of such grooves and the locking projections of the locking ring each extend into a respective one of the transverse grooves.

21. A connector according to claim 20, wherein the plurality of transverse grooves comprises a first pair of parallel grooves and a second pair of parallel grooves extending perpendicularly to the grooves of the first pair.

22. A connector according to claim 20 or claim 21, wherein the flange portion is provided at its circumference with a plurality of radial slots each for reception of a locking projection of the locking ring of another such connector on insertion of the flange portion into a transverse groove of that other connector.

23. A connector according to claim 22, wherein the flange portion is provided on at least one side thereof with an annular channel concentric with the drum portion and communicating with the radial slots so that a locking projection of the other connector received in one of the slots is engageable in the annular channel on relative rotation of the connectors.

24. A connector according to any one of the preceding claims, wherein the drum portion extends on either side of the flange portion.

25. A connector according to claim 24, wherein the drum portion has a respective plurality of apertures or either side of the flange portion and the connector is provided with a respective such captive locking ring on each side of the flange portion, the locking projections of each locking ring extending through the apertures of the plurality at that side of the flange portion.

26. A connector according to any one of the preceding claims, wherein the drum and flange portions are of integral construction and the or each locking ring of multi-part construction.

27. A connector according to claim 26, wherein the or each ring comprises an annular body and separately constructed locking elements non-detachably attached to the body to provide the locking projections.

28. A connector according to claim 27, wherein the locking elements are attached to the annular body by at least one of a material bond and a mechanically positive coupling.

29. A connector according to claim 27 or claim 28, wherein the annular body has at the locations of the locking projections waisted portions of reduced thickness in the axial and radial directions of the body and the locking elements are clipped onto the waisted portions.

30. A connector as claimed in claim 29, wherein each of the locking elements comprises a substantially U-shaped clip portion clipped onto a respective one of the waisted portions of the annular body from outside the body, one of the limbs of the U- shape being prolonged to form the respective locking projection.

31. A connector as claimed in claim 30, wherein each of the waisted portions and the clip portion of the associated locking element have mutually co-operating surfaces defining a wedge lock preventing unclipping of the element by displacement from inside the annular body.

32. A connector according to any one of claims 1 to 25, wherein the or each locking ring is of integral construction and the drum and flange portions are of multi-part construction.

33. A connector according to claim 32, wherein the drum and flange portions comprise a^" separately constructed drum body arid disc body, the disc body having a central passage and the drum body being engaged in the passage and attached to the disc body.

34. A connector according to claim 33, wherein the drum and flange portions have cooperating key-and-keyway aligning means to locate the drum and flange portions in a predetermined rotational relationship.

35. A connector according to claim 33 or claim 34, comprising two such drum bodies each projecting on a respective side of the disc body.

36. A connector according to any one of claims 33 to 35, wherein the or each drum body is attached to the disc body by at least one of a material bond and a mechanically positive coupling.

37. A connector according to any one of claims 33 to 36, wherein the or each drum body is provided with entry channels permitting movement of the locking projections of the locking ring or associated locking ring from an end of the drum body up to the apertures in an unattached state of the drum and disc bodies, the entry passages being closed in the attached state of the bodies.

38. A connector according to any one of the preceding claims, wherein the drum and flange portions and the locking ring are of plastics material.

39. A connector according to any one of claims 1 to 37, wherein the drum and flange portions are of plastics material and the locking ring is of metallic material.

40. A connecting device comprising a connector as claimed in any one of the preceding claims and, as component connectible therewith, an adapter for joining the connector to another such connector with the drum portions of the two connectors in substantially coaxial relationship.

41. A device as claimed in claim 40, wherein the adapter comprises an annular body provided with a respective radially outwardly extending flange at each of two opposite ends thereof, the component surface engageable by the locking projections of the or each locking ring of the connector being the inwardly directed face of a selectable one of the flanges of the adapter. -

42. A device as claimed in claim 41, wherein the flanges are provided with radially extending slots permitting passage of the locking projections through a selected flange received in the drum portion of the connector to enable alignment of the projections at the sides thereof facing the flange portion of the connector substantially with the inwardly directed face of the selected flange.

43. A device as claimed in claim 42, the device comprising a connector according to claim 19 and the part of the component to be held between the shoulder in the interior of the drum portion of the connector and the locking projections of the locking ring being a selectable one of the flanges of the adapter, the locking projections being capable of deflection in a direction away from the shoulder by a predetermined mount on movement of the locking ring out of the unlocking position and the axial dimension of the flange of each adapter being greater by substantially that amount than the spacing of the locking projections from the shoulder so that the projections are pressurably engageable with the inwardly directed face of the selected flange under deflection of the projections.

44. A device according to claim 43, wherein each of the locking projections is provided at the side thereof towards the flange portion of the connector with a chamfer assisting deflection of the projection on transfer from a slot in the selected flange to engagement with the inwardly directed surface of the flange.

45. A device as claimed in any one of claims 42 to 44, the device comprising a connector according to any one of claims 16 to 18 and the recesses in the component being the slots in either flange of the adapter.

46. A connecting device comprising a connector as claimed in claim 23 and, as component connectible therewith, an orthogonal coupling member for use in joining the connector to another such connector with the flange portions of the two connectors in substantially orthogonal relationship.

47. A device as claimed in claim 46, wherein the flange portion of the connector is provided with an annular channel on each side thereof and the coupling member comprises locating means engageable in the channel on one side of the flange portion of one of the connectors when a locking projection of the locking ring of the other one of the connectors is engaged in the channel on the other side.

48. A device according to claim 47, wherein the locating means comprises locating tabs extending on an arcuate path.

49. A device according to claim 47 or claim 48, wherein the coupling member comprises fixing means engageable by at least one other locking projection of the locking ring of the other connector thereby to fix the coupling member to that other connector.

50. A device according to claim 49, wherein the fixing means comprises two oppositely directed fixing lugs each engageable by a respective locking projection of the locking ring of the other connector.

51. A device according to any one of claims 47 to 50, wherein the coupling member comprises positioning wall means engageable with the drum portion of the other connector to lock the coupling member in position relative thereto.