Adjustable framework

Abstract

A lockable ball joint for a foldable table, the ball joint having a neck 38 and a pin 40, the neck supporting table legs 8 and engaging with first track 42 to pivot between collapsed (fig 9a) and exte

Description

[0001] The present invention relates to an adjustable framework. In particular, this invention relates to adjustable frameworks for providing elevated support surfaces for a wide variety of uses. For example, a base part of the framework may be designed to rest on a floor, desk or table, and a support part of the framework may be designed to provide an upper support surface.

[0002] Such support arrangements find use in a very wide variety of applications, for example tables, desks, stools, benches, display stands and the like. It is highly desirable for such units to be movable from a folded position where the framework is at minimum height to an extended position where the distance between the base part and the support part is at or near a maximum level.

[0003] A previous adjustable framework of the present inventor is described in WO 2017 / 108997 Al which discloses a foldable framework comprising a base member and an upper support member and a plurality of legs, each extending between a location on the base member and a location on the upper support member, where the legs are joined to at least one of the base and upper members at the location points via ball joints, and wherein at least one of the ball joints comprises an enclosure surrounding a ball having a laterally projecting portion connected to the leg and wherein the enclosure wall is configured to define a track for the portion projecting from the ball which enables the leg to be moved from a position almost in the plane of the base and support members to, and then past, a position in which each leg is perpendicular to the plane of the base or support member, and then to be held at an angle to that plane.

[0004] A problem with this adjustable framework is that it is not sufficiently stable: once in an extended position, it is easy to fold the framework accidentally by, for example, knocking the upper support member.

[0005] The present invention seeks to provide an improved adjustable framework, including an adjustable framework where each arm (leg) may be held at a position which is perpendicular to the plane of the base or support member.

[0006] According to the present invention there is provided an adjustable framework comprising a base member, a support member and a plurality of arms, the support member being movable between a folded position and an extended position relative to the base member, each arm extending between a location point on the base member and a location point on the support member, and each arm being movable between a collapsed configuration and a raised configuration, wherein the arms are joined to at least one of the base member and support member at the location points via ball joints for enabling the arms to pivot, at least one of the ball joints is a locking ball joint configured to lock an arm in its raised configuration by axial rotation of the arm, the locking ball joint comprising an enclosure and a ball member, the ball member comprises a ball portion, a neck portion projecting from the ball portion and connected to one end of the arm and a pin portion projecting from the ball portion, the enclosure substantially surrounds the ball portion, the enclosure defines an arcuate first track configured to accommodate the neck portion and to confine its movement such that, as the support member is moved from the folded position to the extended position, the neck portion travels in the first track to a closed end, enabling the arm to move between a collapsed configuration and a raised configuration, and the enclosure defines an arcuate second track configured to accommodate the pin portion and to confine its movement such that, as the support member is moved from the folded position to the extended position, the pin portion travels in a first section of the second track and, when the neck portion reaches the closed end of the first track and the arm is axially-rotated, the pin portion travels in a second region of the second track to a closed end of the second track, enabling the arm to be locked in the raised configuration.

[0007] The support member may be movable between a folded position and an extended position relative to the base member by a lifting and twisting action.

[0008] In the previous adjustable framework of the present inventor described in WO 2017 / 108997 Al, an outer rotatable cap is disclosed for providing a mechanism to enable the base member and support member parts of the framework to be fixed or locked at a given distance from one another. However, the inventor has found that this arrangement is not effective in providing a structure which is sufficiently stable for everyday use, for example when the framework in its extended position is picked up using its support member.

[0009] In contrast, the features of the pin portion and the second track in the lockable ball joint provide an elegant mechanism for locking the arm in the raised configuration, thereby providing an adjustable framework which is sufficiently stable for everyday use in its extended position.

[0010] This locking feature is preferably an internal mechanism, such that the pin portion and the second track are internal features of the locking ball joint. The locking feature may be activated by simple axial rotation of the arm. The axial rotation may be achieved, for example, by manually rotating a shaft of the arm or by manually rotating a handle provided on the shaft of the arm. To unlock the arm, the shaft of the arm is rotated in an opposite direction, thereby moving the pin portion from the closed end of the second region of the second track to the first region of the second track.

[0011] The first track may extend generally in a direction which spans the distance between the base member and the support member, this being the general direction of the arm when it is moved between its collapsed configuration and its raised configuration.

[0012] The second track may extend generally in a direction which is approximately coplanar with the adjustable framework in its folded position.

[0013] The first region of the second track may lie in a plane which is substantially perpendicular to the axis of rotation of the arm at the point when the base member and the support member are at their maximum distance from one another.

[0014] The second region of the second track may lie in a plane which is substantially perpendicular to the arm in its raised and locked configuration.

[0015] The enclosure may comprise a resilient tab located at or adjacent the closed end of the second track to releasably retain the pin portion of the ball member at the closed end of the second track. The tab may be integrally formed at or adjacent the closed end of the second track to simplify the manufacturing process of the enclosure. In one embodiment, the tab may provide an audible click when the pin portion of the ball member reaches the closed end of the second track, thereby indicating to a user that the arm has been locked in its raised configuration.

[0016] The enclosure may comprise a clip configured to releasably retain the neck portion in position at the closed end of the first track. This is useful for stabilising the arm in its raised configuration before the arm is axially rotated and locked in position. This clip may be an E-clip: the three prongs of an E-clip make contact with the neck portion for effective retention of the arm in its raised configuration.

[0017] The enclosure may comprise a base socket member and a cover socket member which together define a socket cavity, the ball portion being adapted to revolve in the socket cavity, and wherein the socket cavity is in communication with the first track and with the second track. The ball portion preferably has a substantially spherical body with the neck portion and the pin portion laterally-projecting at different angles from the body.

[0018] The first track may be provided, at least in part, by the cover socket member. In this regard, the first track may be formed by an aperture in the wall of the cover socket member.

[0019] The enclosure may comprise a cap which overlies at least part of the cover socket member and the first track may be provided, at least in part, by the cap. In this regard, the first track may be formed by an aperture in the wall of the cap overlying the aperture in the wall of the cover socket member.

[0020] The second track may be provided, at least in part, by the base socket member and / or the cover socket member. In this regard, the base socket member and the cover socket member may together define the second track. Alternatively, either the base socket member or the cover socket member may define the second track: the second track may be formed by a groove formed in an internal wall of the relevant socket member.

[0021] The pin portion may be radially spaced from the neck portion by an angle of between 45 and 135 degrees, preferably between 60 and 120 degrees, more preferably between 75 and 105 degrees. In a preferred embodiment, the pin portion is radially spaced from the neck portion by about 90 degrees. The pin portion may extend in a direction which is substantially perpendicular to the longitudinal axis of the arm.

[0022] More than one pin portion may project from the ball portion of the ball member. When a plurality of pin portions is present (eg two or three pin portions), they may each be movable in the same or different second track to lock the arm in a raised and locked configuration by a single axial rotation of the arm.

[0023] The base member and the support member may be made up entirely of elongate members linked to one another to form the base member and the support member, with these two being held together by the arms. The base member and the support member may be planar members. The planar members may have substantially the same outer shape and size so that they stack neatly when the structure is folded, with a space between them accommodating the collapsed arms. The base member and / or the support member may be open planar members (for example when made up of elongate members) or solid planar members (for example when made of a sheet material). The base member and / or the support member may be planar members with one or more cut out portions, for example to hold a receptacle.

[0024] One or both of the base member and the support member may have a peripheral skirt or rim to enclose the arms fully when the framework is folded. Alternatively, provided there is sufficient clearance to allow for the twisting as the framework is extended, one of the base member and the support member may nest inside the other. This enables a structure to be incorporated into a floor with its top flush with the remainder of the floor when the structure is folded or collapsed.

[0025] A recessed portion may be provided at the location point on the base member or the support member (as appropriate) to house at least part of the locking ball joint. This recessed portion provides support to the locking ball joint when it is connected to the base member or the support member. This recessed portion also assists in minimising the height of the adjustable framework in its folded position, since the distance between the base member and support member is reduced.

[0026] In one embodiment, at least one of the base member and the support member is a planar member and the locking ball joint is configured such that, when the arm is locked in its raised configuration, the arm is substantially perpendicular to the planar member.

[0027] This arrangement of a stable, vertical, raised arm in use of the adjustable framework is desirable in engineering terms but can be mechanically difficult to achieve as the arm readily collapses under gravity. However, the features of the pin portion and the second track in the lockable ball joint are effective in locking the arm in a stable, vertical, raised configuration.

[0028] In this embodiment of an arm in a vertical, raised configuration, the first section of the second track and the second section of the second track may be coplanar. When the adjustable framework is positioned upright for use with the base member positioned below the support member, the first and second sections of the second track may extend substantially horizontally. The first track may extend in a generally vertical direction between the base member and the support member.

[0029] In an alternative embodiment, at least one of the base member and the support member is a planar member and the locking ball joint is configured such that, when the arm is locked in its raised configuration, the arm is not substantially perpendicular to the planar member.

[0030] An arrangement of a non-vertical, raised arm in an adjustable framework is described in WO 2017 / 108997 Al whose contents are incorporated herein by reference. However, in contrast to this prior arrangement, the features of the pin portion and the second track in the lockable ball joint of the present invention are effective in locking the arm in a stable, non-vertical, raised configuration.

[0031] The locking ball joint may be configured such that, as the support member is moved from the folded position to the extended position, the neck portion travels to the closed end of the first track via a position where the arm is substantially perpendicular to the planar member. Accordingly, when the support member is moved between a folded position and an extended position relative to the base member, the arm moves to and then past a vertical, raised configuration by virtue of the shape of the first track.

[0032] In this embodiment of an arm in a non-vertical, raised configuration, the first section of the second track and the second section of the second track may not be coplanar. When the adjustable framework is positioned upright for use with the base member positioned below the support member, the second section of the track may slope gradually downwards from the first section to the closed end of the second track, such that gravity assists the travel of the pin portion in the second region of the second track. The first region of the second track may extend in a substantially horizontal plane. The second region of the second track may extend in plane which is substantially perpendicular to the axial length of the arm in its non-vertical, raised and locked configuration. The first track may extend in a generally vertical direction between the base member and the support member.

[0033] One of the base member and the support member may be provided with at least one projecting portion and the other of the base member and the support member may be provided with at least one indented portion, the indented portion being configured to accommodate the projecting portion such that adjacent foldable frameworks are inter-connectable. A stable stack of adjustable frameworks may be formed as a result.

[0034] In one embodiment, both the base member and the support member of the adjustable framework are planar members with at least one projecting portion being provided on an external planar surface of one of the planar members and at least one indented portion being provided on an external planar surface of the other planar member.

[0035] The projecting portion and the indented portion may each be arcuate in shape in plan view. The projecting portion and the indented portion may be provided between adjacent location points. The projecting portion and the indented portion may be provided adjacent an arm in its collapsed configuration. The collapsed arm may be located inwardly of the adjacent projecting portion and the adjacent indented portion relative to an outer edge of the adjustable framework. The projecting portion and the indented portion may extend in the direction of an adjacent collapsed arm. In one example, the adjustable framework has three arms, three projecting portions and three indented portions. In another example, the adjustable framework has four arms, four projecting portions and four indented portions.

[0036] In an alternative embodiment, the support member may itself act as a base member in an extended framework, i.e. it may carry a second support member so as to produce a "two-decker" framework. This enables the second support member to be essentially at twice the height from the horizontal surface, such as the ground or a floor on which the two-decker framework is set, as the intermediate member which has a dual function, constituting the support member of the lower framework and the base member of the upper framework. A three-decker or four-decker arrangement may be produced analogously if it is desired to produce a taller, relatively narrow overall structure, such as a lectern or projector stand, which still has a relatively small "footprint". Multiple arrangements of this sort may have successive support surfaces of different sizes. For example, a set of discs of decreasing size may produce an easily erected multi-shelf merchandiser or a conical "Christmas tree" one; each disc may even nest in the one below it when the framework is in a folded position.

[0037] All of the arms may be joined to at least one of the base member and the support member at the location points via the lockable ball joints. In one embodiment, all of the arms are joined to both the base member and the support member at the location points via the lockable ball joints.

[0038] As the base member and support member are moved apart, because they are fixed to the arms, the arms may move from a position where they lie at an acute angle to the planes of the base member and support member through to a position perpendicular to the plane of each, at which point the base member and the support member are at their maximum distance from one another. In one embodiment, the arms are locked in this position. In another embodiment, by further rotating the base member and support member relative to one another, the arms may be moved and locked so that they lie at an angle from the vertical. The shape of the first track in the lockable ball joint determines the point at which the arm cannot move further, whether that be at a vertical position or at an angle from the vertical.

[0039] Such a framework may be rapidly erected from the folded position by twisting the base member relative to the support member. As this takes place, the base member and the support member may move from being adjacent to being held apart by the arms, to a position where the support member lies above the base member by a certain height, corresponding to the length of the arms. The twisting movement may be achieved by grasping the support member and twisting it while lifting it up, or the support member may be lifted enabling the base member to rotate as the support member is lifted. If the lifting is sufficiently fast, the momentum of the base member carries the neck portion connected to an arm to the closed end of the first track ready for locking of the arm and the erected framework can simply be rested on the floor or other horizontal surface such as a tabletop.

[0040] If the base member is itself fixed in position, for example constituting a floor of a room or decking on a balcony or patio, then the support member is turned about a vertical axis as it is lifted. This may be achieved by a simple vertical lifting movement of the support member, assuming the support member is freely rotatably mounted to the arms at the location points. Alternatively, the base member may be mounted so that it can rotate about a vertical axis as the support member is lifted, e.g. by being set on a circular fixed track in a floor.

[0041] In one embodiment, when the foldable framework is in a folded position and the arms are in a collapsed configuration, each ball joint at a location point on the base member is adjacent to and substantially coplanar with a ball joint at a location point on the support member. At least one of the ball joints is a locking ball joint.

[0042] The arm may be provided with a handle which extends substantially perpendicularly to the axis of rotation of the arm. This handle may be used to axially rotate the arm. Instead or in addition, the handle may be labelled with the words 'locked' and 'unlocked' or an appropriate symbol such as a padlock to provide a visual guide to a user of whether the arm is in a locked or unlocked axial position.

[0043] In one embodiment, the positions of the location points on the base member and the support member respectively are at or adjacent the corners of a shape which is generally or exactly that of a polygon. Preferably the polygon is a triangle, a square, a pentagon or a hexagon. In one example of the shape, the vertices of the polygon are cut off to define its corners, with location points being positioned at or adjacent the corners.

[0044] A recessed region may be provided in a planar base member and / or a planar support member to define the shape where location points are positioned at or adjacent its corners. In one example, a triangular recessed region in a circular planar member defines the shape, with the vertices of the triangle optionally removed to define its corners. In another example, a square recessed region in a square planar member defines the shape, with the vertices of the square optionally removed to define its corners. In a further example, a triangular recessed region in a square planar member defines the shape, with the vertices of the triangle optionally removed to define its corners.

[0045] The length of each arm in its collapsed configuration may be less than the side length of the respective polygon. Each arm may be extendable to provide a maximum arm length at the raised configuration. For example, each arm may be telescopic or each arm may be provided with one or more joints to enable bending along its shaft. The present invention is not limited to the number of arms present. Three to eight arms are preferably present, each arm extending between the location point on the base member and the location point on the support member.

[0046] The present invention also provides a method of extending an adjustable framework, the method comprising moving the support member from a folded position to an extended position relative to the base member, allowing the arms to move from a collapsed configuration to a raised configuration, and axially-rotating an arm connected to a neck portion of a locking ball joint to lock the arm in its raised configuration.

[0047] In its simplest version, the present invention provides an adjustable framework which can be expanded from a folded position where it takes up little space to an extended position where it can act as a support surface, for example to hold something above a floor.

[0048] A series of such framework structures may enable the uppermost support member to be rapidly erected to provide a raised support surface which is stable in use but where the structure can be easily collapsed by unlocking the arms and rotating the upper most support member relative to the base member in the opposite direction to that needed to raise the support member.

[0049] Although the framework will work if only one of the arms is provided with a lockable ball joint type, it is preferred that all of the ball joints at the location points on the base member and / or the support member are of the same construction so as to share the load evenly between themselves when the support member is extended from the base member and loaded by placing something on it. When a lockable ball joint is connected to each end of an arm, axial-rotation of the arm may cause it to be locked at both ends in the raised configuration.

[0050] When one or more of the arms is provided with a lockable ball joint at the relevant location point on the base member and / or the support member, the other arms may be provided with non-lockable ball and socket joints at the relevant location points on the base member and / or the support member.

[0051] The present invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is an exploded top perspective view of a base member according to the present invention; Figure 2 is an exploded top perspective view of a support member according to the present invention; Figure 3 is a transparent top perspective view of an adjustable framework according to a first embodiment of the present invention in a folded position; Figure 4 is a transparent top perspective view of the adjustable framework of figure 3 in an extended position; Figure 5 is a transparent top perspective view of an adjustable framework according to a second embodiment of the present invention in a folded position; Figure 6 is a transparent top perspective view of the adjustable framework of figure 5 in an extended position; Figure 7 is a top perspective view of a locking ball joint for use in the first embodiment of the present invention with a plug portion absent; Figure 8 is a top perspective view of a locking ball joint for use in the second embodiment of the present invention; Figure 9A is a transparent top perspective view of a locking mechanism including a locking ball joint for use in the first embodiment of the present invention with an arm in a collapsed configuration; Figure 9B is a transparent top perspective view of the locking mechanism of figure 9A with an arm in a raised and locked configuration; Figures 10A to 10E are a series of transparent top perspective views of a locking mechanism including a locking ball joint for use in the second embodiment of the present invention with an arm in a collapsed configuration, in a semi-raised configuration, in a vertical configuration, in a raised configuration and in a raised and locked configuration, respectively; Figure 11A is an exploded top perspective view of components of a locking mechanism according to the first embodiment of the present invention; Figure 11B is an exploded bottom perspective view of components of the locking mechanism of figure 11A; Figure 12A is an exploded top perspective view of components of a locking mechanism according to the second embodiment of the present invention; Figure 12B is an exploded bottom perspective view of components of the locking mechanism of figure 12A; Figure 13 is a top perspective view of an assembled locking mechanism for use in the first embodiment of the invention; Figure 14 is a side perspective view of part of an assembled locking mechanism for use in the first embodiment of the invention; and Figure 15 is a side perspective view of part of an assembled locking mechanism for use in the second embodiment of the invention.

[0052] Referring to figures 1 to 6, an adjustable framework 2 in accordance with the present invention comprises a base member 4, a support member 6 and three arms 8. Support member 6 is movable between a folded position (see figures 3 and 5) and an extended position (see figures 4 and 6) relative to base member 4 by a twisting and lifting action.

[0053] Each arm 8 extends between a location point 10 on base member 4 and a location point 12 on support member 6. Each arm is movable between a collapsed configuration (see figures 3 and 5) and a raised configuration (see figures 4 and 6).

[0054] Referring to figure 1, base member 4 is a circular, solid planar member. On an upper surface of base member 4, a recessed portion 14 is provided at each location point 10. On an opposing lower surface of base member 4, a series of three arcuate ribs 16, being projecting portions, are provided: ribs 16 are equidistant from one another.

[0055] Referring to figure 2, support member 6 is a circular, solid planar member comprising three layers. An upper layer 18 is a circular planar support surface provided with a series of three arcuate grooves 20, being indented portions positioned between location portions 12: grooves 20 are equidistant from one another and are each shaped and positioned to accommodate one of ribs 16. An intermediate layer 22 and lower layer 24 are also circular and planar. Lower layer 24 is provided with a recessed region 26 which is substantially triangular in shape with the vertices of an equilateral triangle removed to define the corners of the shape. A location point 12 is positioned at or adjacent each corner of this triangular shape. A recessed portion is therefore provided at each location point 12 in the assembled base member.

[0056] The provision of ribs 16 and grooves 20 means that a stable stack of adjustable frameworks may be formed: a base member 4 of one framework is placed on a flat surface; the framework is extended so that support member 6 provides a support surface; a base member 4 of another framework is placed on support member 6 with ribs 16 of base member 4 of the upper framework fitting into grooves 20 of support member 6 of the lower framework: additional frameworks may be stacked accordingly.

[0057] Base member 4 and support member 6 may be made of wood, plastic, metal and / or a composite material. In one example, they are made of a wooden sheet material, such as mdf board.

[0058] Referring to figures 3 to 6, one end of each arm 8 is joined to base member 4 at location point 10. The other end of each arm 8 is joined to support member 6 at location point 12. Each arm is joined at the location points via ball joints for enabling the arms to pivot.

[0059] With reference to figures 7 and 8, one or both ends of each arm 8 are joined at the location point via a locking ball joint 28 which is configured to lock the arm in its raised configuration by axial rotation of the arm about its shaft 30 which may be knurled to enable it to be turned more easily by hand. Locking ball joint 28 may be labelled to mark a locked and an unlocked position of the raised arm.

[0060] As shown in figures 3 and 5, when the foldable framework is in a folded position and arms 8 are in a collapsed configuration, each ball joint 28 at a location point 10 on base member 4 is adjacent to and substantially coplanar with a ball joint 28 at a location point 12 on support member 6.

[0061] Referring to figures 9A, 9B and 10A to 10E, locking ball joint 28 comprises an enclosure 32 and a ball member 34. Ball member 34 comprises a ball portion 36, a neck portion 38 projecting from ball portion 36 and connected to one end of arm 8 and a pin portion 40 projecting from ball portion 36. Enclosure 32 substantially surrounds ball portion 36. Pin portion 40 is radially spaced from neck portion 38 by 90 degrees, such that pin portion 40 extends in a direction which is perpendicular to shaft 30.

[0062] Enclosure 32 defines an arcuate first track 42 configured to accommodate neck portion 38 and to confine its movement such that, as support member 6 is moved from the folded position to the extended position of the adjustable framework, neck portion 38 travels in first track 42 to a closed end 44, enabling arm 8 to move between a collapsed configuration and a raised configuration. Neck portion 38 abuts closed end 44 when the arm is in a raised configuration.

[0063] Enclosure 32 also defines an arcuate second track 46 configured to accommodate pin portion 40 and to confine its movement such that, as support member 6 is moved from the folded position to the extended position, pin portion 40 travels in a first section 48 of second track 46: when neck portion 38 reaches closed end 44 of first track 42, arm 8 is axially-rotated about shaft 30 causing pin portion 40 to travel in a second region 50 of second track 46 to a closed end 52, enabling arm 8 to be locked in the raised configuration. Pin portion 40 abuts closed end 52 when the arm is in a raised and locked configuration.

[0064] In the first embodiment of figures 9A and 9B, a resilient tab 54 is provided at or adjacent closed end 52 of second region 50 to releasably retain pin portion 40 of ball member 34 at closed end 52. Tab 54 may provide an audible click when pin portion 40 of ball member 34 reaches closed end 52, thereby indicating to a user that arm 8 has been locked in its raised configuration.

[0065] Referring to figures 10A to 10E, axial rotation of arm 8 may be achieved, for example, by manually rotating shaft 30 or by manually rotating a handle 56 provided on shaft 30 of the arm. To unlock arm 8, shaft 30 is rotated in an opposite direction, thereby moving pin portion 40 from closed end 52 of second region 50 to first region 48 of second track 46. Handle 56 may labelled with the words 'locked' and 'unlocked' as a visual guide to a user of whether arm 8 is in a locked or unlocked axial position.

[0066] When extending the adjustable framework, base member 4 and support member 6 are moved apart and, since they are fixed to arms 8, the arms move from a position where they lie at an acute angle to the planes of base member 4 and support member 6 through to a position perpendicular to the plane of each, at which point base member 4 and support member 6 are at their maximum distance from one another.

[0067] In the first embodiment of figures 3, 4, 7, 9, 11,13 and 14, the arms are locked in this vertical position.

[0068] In the second embodiment of figures 5, 6, 8, 10, 12 and 15, by further rotating base member 4 and support member 6 relative to one another, arms 8 are moved and locked so that they lie at an angle from the vertical. In this embodiment, arms 8 move to and then past a vertical, raised configuration.

[0069] With reference to figures 7 and 8, the shape of first track 42 in lockable ball joint 28 determines the point at which arm 8 cannot move further and is in its raised configuration, whether that be at a vertical position or at an angle from the vertical. Either way, first track 42 extends in a generally vertical direction between base member 4 and support member 6.

[0070] Whether arm 8 is vertical or non-vertical in its raised configuration determines the shape of second track 46 for locking arm 8 in its raised configuration.

[0071] As shown in figures 9A and 9B, in the embodiment where the arm is vertical in its raised configuration, first section 48 and second section 50 of second track 46 are continuous and extend substantially horizontally in the same plane.

[0072] Referring to figure 9A, arm 8 is in a collapsed configuration with shaft 30 in a substantially horizontal orientation. Neck portion 38 is in a lower region of first track 42 and pin portion 40 extends perpendicularly to neck portion 38 and is located in first section 48 of second track 46.

[0073] From the collapsed configuration, arm 8 is moved upwardly as support member 6 is lifted above base member 4. Neck portion 38 moves upwardly in first track 42. Ball portion 36 revolves in socket cavity 62. Pin portion 40 is retained in first section 48 of second track 46, causing arm 8 to twist as it rises.

[0074] Referring to figures 9B, arm 8 is in a raised and locked configuration with shaft 30 in a substantially vertical orientation. Neck portion 38 is in an upper region of first track 42 at closed end 44. Pin portion 40 extends perpendicularly to neck portion 38 and is located in second section 50 of second track 46 at closed end 52. Arm 8 has been axially-rotated clockwise about shaft 30 such that pin portion 40 traverses tab 54 as it travels from first section 48 to second section 50. Tab 54 helps to retain pin portion 40 at closed end 52 of second track 46. Movement of pin portion 40 in second track 46 to closed end 52 results in pin portion 40 being perpendicular to the direction of travel required for the arm to return to its collapsed configuration: pin portion 40 is therefore in its strongest position to resist this travel and locks arm 8 in place.

[0075] To unlock arm 8, it is manually rotated in an anti-clockwise direction such that pin portion 40 travels from second section 50 to first section 48. From there, movement of support member 6 relative to base member 4 causes arm 8 to return to the collapsed configuration of figure 9A. The locking mechanism in figures 9A and 9B is locked by clockwise rotation of shaft 30 whereas those of figures 7,13 and 14 are locked by anti-clockwise rotation of shaft 30.

[0076] As shown in figures 10A to 10E, in the embodiment where the arm is at an angle from the vertical in its raised configuration, first section 48 and second section 50 of second track 46 are continuous but not coplanar. First section 48 extends substantially horizontally and second section 50 slopes gradually downwards away from first section 48 to closed end 52. No tab 54 is shown in figures 10A to 10E.

[0077] Referring to figure 10A, arm 8 is in a collapsed configuration with shaft 30 in a substantially horizontal orientation. Neck portion 38 is in a lower region of first track 42 and pin portion 40 extends perpendicularly to neck portion 38 and is located in first section 48 of second track 46.

[0078] Referring to figure 10B, arm 8 is moved upwardly as support member 6 is lifted above base member 4. Neck portion 38 moves upwardly in first track 42. Ball portion 36 revolves in socket cavity 62. Pin portion 40 is retained in first section 48 of second track 46, causing arm 8 to twist as it rises. Handle 56 rotates as a result.

[0079] Referring to figure 10C, arm 8 continues to move upwardly to a position where shaft 30 is in a substantially vertical orientation. Pin portion 40 travels in first section 48 towards second section 50. Handle 56 continues to rotate in anti-clockwise direction.

[0080] Referring to figure 10D, arm 8 continues past a vertical position to reach a rest position where neck portion 38 abuts closed end 44 of first track 42. Pin portion 40 reaches the position where first section 48 and second section 50 of second track 46 meet. Second section 50 lies in a plane which is perpendicular to the axis of rotation of arm 8 in this rest position. Handle 56 continues to rotate.

[0081] Referring to figure 10E, arm 8 is manually rotated anti-clockwise about shaft 30. Handle 56 is optionally used to effect this rotation. Pin portion 40 moves to a position where it abuts closed end 52 of second track 46 to lock arm 8 in position. Optionally, a resilient tab (not shown) is present to assist with retaining pin portion 40 in this locked position.

[0082] To unlock arm 8, it is manually rotated clockwise to return to the rest position of figure 10D. From there, movement of support member 6 relative to base member 4 causes arm 8 to return to the collapsed configuration of figure 10A via the positions of figures 10C and 10B.

[0083] Referring to figures 11A, 11B, 12A and 12B, enclosure 32 comprises a plug 58 being a base socket member and a bracket 60 being a cover socket member which together define a socket cavity 62 for receiving and retaining ball portion 36. Bracket 60 overlies plug 58. Enclosure 32 also comprises a cap 64 which overlies bracket 60 such that cap 64 extends from the top of bracket 60 to just above its lugs 66.

[0084] First track 42 is a contoured slot formed by an aperture in the wall of bracket 60 coaligned with an aperture in the wall of cap 64. The position of closed end 44 determines the maximum extent to which arm 8 can travel as it is moved from its collapsed configuration to its raised configuration. If desired, first track 42 may be extended somewhat further than shown, or reduced.

[0085] Second track 46 is a contoured groove formed by an upper edge of plug 58 and an internal edge of bracket 60. The position of closed end 52 determines the locked position of arm 8, being the furthest point of travel of pin portion 40 in second track 46. If desired, second track 46 may be extended somewhat further than shown, or reduced.

[0086] Socket cavity 62 is in communication with first track 42 and second track 46.

[0087] To form ball member 34, ball portion 36 is provided with an aperture for pin portion 40 and an aperture for neck portion 38. In this example, neck portion 38 is integrally formed with arm 8 and is provided with an aperture to receive pin portion 40 via the aperture in ball portion 36. Ball member 34 is thereby firmly connected to arm 8, enabling the arm and the ball member 34 to move together.

[0088] Ball member 34 and arm 8 may be made of metal or a plastic material or a composite material. Enclosure 32 may be may be made of metal or a plastic material or a composite material.

[0089] With reference to figures 11A, 11B, 12A and 12B, plug 58 of ball joint 28 is secured to base member 4 (as shown) or to support member 6 (not shown) by means of screws 65. These screws are retained by respective screw-threaded lugs 66 of bracket 60 via holes in the planar member at the relevant location point. Plugs 58 are secured to base member 4 at location points 10 in recessed portions 14. The recessed portions at the location points in base member 4 and support member 6 support plug 58 and bracket 60: for example, lugs 66 of each bracket 60 fit snuggly within recessed portions 14. The provision of recessed portions also minimises the distance between base member 4 and support member 6 when the framework is in its folded position.

[0090] In the first embodiment of figures 11A, 11B and 13, enclosure 32 comprises a clip 68 such as a metal E-clip to retain neck portion 38 when it reaches closed end 44 of first track 42. Clip 68 acts to stabilise arm 8 in its raised configuration before the arm is axially rotated and locked in position. Such a clip may also be used in the second embodiment of figures 12A and 12B.

[0091] Referring to figures 14 and 15, plug 58 is shown without bracket 60 and cap 64. A bottom portion of second track 46 is defined by part of an upper circumferential edge of plug 58. In both figures, pin portion 40 is travelling in an anti-clockwise direction in second track 46 towards closed end 52. Resilient tab 54 is provided adjacent closed end 52. Tab 54 is a projection which projects into second section 50 of second track 46. Tab 54 is depressed as pin portion 40 travels over it and tab 54 returns to its original position once pin portion 40 has passed over it, creating an audible click sound. Pin portion 40 is retained adjacent closed end 52 by tab 54. Tab 54 is integrally formed with the body of plug 58 in these examples and is alternatively fitted as a separate component. Pin portion 40 abuts closed end 52 to lock arm 8 in its raised configuration.

[0092] When using the locking ball joints of figures 7, 8,10, 14 and 15, the support member is movable between a folded position and an extended position by an anticlockwise twisting motion: one or more arms are then axially-rotated in an anticlockwise direction to lock them in a raised configuration. To return the support member to the folded position, the or each locked arm is unlocked by axial rotation in a clockwise direction and the support member is movable between the extended position and the folded position by a clockwise twisting motion. The present invention is not limited to these twisting and rotating directions. Also, the direction of axial-rotation to lock or unlock the arm may be different to the twisting direction of the support member when respectively extending or folding the support member.

[0093] As can be seen, the present invention provides an adjustable framework which can be easily deployed, which requires no external source of power to operate it, which is stable in its extended position and which can be collapsed when not required after use into a neat and compact unit for storage. It can be produced in a range of sizes and shapes to suit its intended purpose.

Claims

1. An adjustable framework comprising a base member, a support member and a plurality of arms, the support member being movable between a folded position and an extended position relative to the base member, each arm extending between a location point on the base member and a location point on the support member, and each arm being movable between a collapsed configuration and a raised configuration, wherein:the arms are joined to at least one of the base member and support member at the location points via ball joints for enabling the arms to pivot,at least one of the ball joints is a locking ball joint configured to lock an arm in its raised configuration by axial rotation of the arm, the locking ball joint comprising an enclosure and a ball member,the ball member comprises a ball portion, a neck portion projecting from the ball portion and connected to one end of the arm and a pin portion projecting from the ball portion,the enclosure substantially surrounds the ball portion,the enclosure defines an arcuate first track configured to accommodate the neck portion and to confine its movement such that, as the support member is moved from the folded position to the extended position, the neck portion travels in the first track to a closed end, enabling the arm to move between a collapsed configuration and a raised configuration, andthe enclosure defines an arcuate second track configured to accommodate the pin portion and to confine its movement such that, as the support member is moved from the folded position to the extended position, the pin portion travels in a first section of the second track and, when the neck portion reaches the closed end of the first track and the arm is axially-rotated, the pin portion travels in a second region of the second track to a closed end of the second track, enabling the arm to be locked in the raised configuration.

2. An adjustable framework as claimed in claim 1, wherein the enclosure comprises a resilient tab located at or adjacent the closed end of the second track to releasably retain the pin portion of the ball member at the closed end of the second track.

3. An adjustable framework as claimed in claim 1 or claim 2, wherein the enclosure further comprises a clip configured to releasably retain the neck portion in position at the closed end of the first track.

4. An adjustable framework as claimed in any preceding claim, wherein the first region of the second track lies in a plane which is substantially perpendicular to the axis of rotation of the arm at the point at which the base member and the support member are at their maximum distance from one another.

5. An adjustable framework as claimed in any preceding claim, wherein the second region of the second track lies in a plane which is substantially perpendicular to the axis of rotation of the arm in its raised and locked configuration.

6. An adjustable framework as claimed in any preceding claim, wherein the enclosure comprises a base socket member and a cover socket member which together define a socket cavity, the ball portion being adapted to revolve in the socket cavity, and wherein the socket cavity is in communication with the first track and with the second track.

7. An adjustable framework as claimed in claim 6, wherein the first track is provided, at least in part, by the cover socket member.

8. An adjustable framework as claimed in claim 7, wherein the enclosure further comprises a cap which overlies at least part of the cover socket member and wherein the first track is provided, at least in part, by the cap.

9. An adjustable framework as claimed in any one of claims 6 to 8, wherein the second track is provided, at least in part, by the base socket member.

10. An adjustable framework as claimed in any one of claims 6 to 9, wherein the second track is provided, at least in part, by the cover socket member.

11. An adjustable framework as claimed in any preceding claim, wherein the pin portion is radially spaced from the neck portion by an angle of between 45 and 135 degrees.

12. An adjustable framework as claimed in claim 11, wherein the pin portion is radially spaced from the neck portion by an angle of between 60 and 120 degrees.

13. An adjustable framework as claimed in claim 12, wherein the pin portion is radially spaced from the neck portion by an angle of between 75 and 105 degrees, preferably at an angle of substantially 90 degrees.

14. An adjustable framework as claimed in any preceding claim, wherein a recessed portion is provided at the location point to house at least part of the locking ball joint.

15. An adjustable framework as claimed in any preceding claim, wherein at least one of the base member and the support member is a planar member and wherein the locking ball joint is configured such that, when the arm is locked in its raised configuration, the arm is substantially perpendicular to the planar member.

16. An adjustable framework as claimed in claim 15, wherein the first section of the second track and the second section of the second track are coplanar.

17. An adjustable framework as claimed in any one of claims 1 to 14, wherein at least one of the base member and the support member is a planar member and wherein the locking ball joint is configured such that, when the arm is locked in its raised configuration, the arm is not substantially perpendicular to the planar member.

18. An adjustable framework as claimed in claim 17, wherein the locking ball joint is configured such that, as the support member is moved from the folded position to the extended position, the neck portion travels to the closed end of the first track via a position where the arm is substantially perpendicular to the planar member.

19. An adjustable framework as claimed in claim 17 or claim 18, wherein the first section of the second track and the second section of the second track lies are not coplanar.

20. An adjustable framework as claimed in any preceding claim, wherein one of the base member and the support member is provided with at least one projecting portion and the other of the base member and the support member is provided with at least one indented portion, the indented portion being configured to accommodate the projecting portion such that adjacent foldable frameworks are inter-connectable.

21. An adjustable framework as claimed in any preceding claim, wherein all of the arms are joined to at least one of the base member and the support member at the location points via the lockable ball joints.

22. An adjustable framework as claimed in claim 21, wherein all of the arms are joined to both the base member and the support member at the location points via the lockable ball joints.

23. An adjustable framework as claimed in any preceding claim, wherein, when the foldable framework is in a folded position and the arms are in a collapsed configuration, each ball joint at a location point on the base member is adjacent to and substantially coplanar with a ball joint at a location point on the support member.

24. An adjustable framework as claimed in any preceding claim, wherein the arm is provided with a handle which extends substantially perpendicularly to the axis of rotation of the arm.

25. A method of extending an adjustable framework as claimed in any preceding claim, the method comprising moving the support member from a folded position to an extended position relative to the base member, allowing the arms to move from a collapsed configuration to a raised configuration, and axially-rotating an arm connected to a neck portion of a locking ball joint to lock the arm in its raised configuration.

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