This invention relates to a flat pack frame that is three-dimensional in an erected condition but that can pack as a flat pack for transport and storage purposes and wherein, in the erected condition, multiple frame members radiate from a central assembly axis.

BACKGROUND TO THE INVENTION

Three-dimensional frames are generally problematic from a transport and storage point of view unless they can be packed as a flat pack which means that all the large components can be packed one on top of the other with any protective material between them, typically in a relatively flat box in which they can be conveniently transported, stored and handled. The same problems exist irrespective of the size of the three-dimensional frame in the erected condition and the difficulty extends across the spectrum from small items such as lamp bases and stands to larger items such as tables, stools, fern stands and numerous other items of freestanding furniture.

The difficulty with many flat pack frames is that they are sometimes complex to assemble and, as it is generally the intention that a purchaser carry out the necessary assembly without any assistance, and simply according to instructions contained within the package, a simple assembly procedure is obviously preferred. The problems are the same whether or not the item of furnishing is intended to be collapsible or to remain permanently in the erected condition, once it has been assembled. SUMMARY OF THE INVENTION

In accordance with this invention there is provided a flat pack frame comprising at least two flat frame members that have an erected condition in which the frame has an assembly axis from which at least three flat frame sections extend in a generally radial direction relative to the assembly axis to form a three-dimensional frame, and wherein each frame section has a connection zone having an edge that extends generally parallel to the assembly axis and the edges of the other frame sections with the connection zones being directed outward and being located generally on the surface of a circular cross-sectioned cylinder, with the connection zone of at least one frame section having a serrated edge that conforms to an internal screw thread of a connecting collar that serves as a fastener to hold the frame sections radially captive in their erected condition with the serrated edge engaging the inner screw thread of the connecting collar; and formations and optionally one or more connector elements associated with the frame sections for maintaining them in their angular and axial positions relative to each other.

Further features of the invention provide for two frame sections to be connected to each other and to form a single flat frame member; for there to be an even number of frame sections arranged in pairs thereof with the frame sections of each pair being connected to each other and forming a single flat frame member; for the connection zones of the frame sections to be located towards one end of the erected frame with the other ends of the frame members being located relative to each other by formations either in the frame members themselves or in a connector element, or both; and for the frame members to be cut from a suitably rigid sheet material that may be a metal sheet, a plastics sheet, a laminated sheet especially one of laminated wooden plies; or any other suitable sheet material. A still further feature of the invention provides for the one or more connector elements to include one or more supporting discs that serve to locate the connection zones relative to each other from the inside thereof with notches in the supporting discs receiving the thickness of the frame members on the inside of the connection zones that also have notches receiving the inner edges of the notches of the supporting disc to restrain the connection zones from moving inwards or axially in the installed position.

In the event that the connection zone of more than one frame section, or even all of them, are provided with a serrated edge, it is important that the serrations be located axially on a helical path corresponding to that of the internal thread of the internally screw threaded connecting collar so that the thread can register properly with all of the serrations. In such an instance, as may be required, individual frame members may be arranged such that their angular position relative to other frame members is easy to determine in order that the serrations on the connection zones lie correctly on the helical path of the internal screw thread of a connecting collar.

It will be understood that, should more than one connection zone have a serrated edge, the exact axial position of the apexes of the serrations will need to vary according to the pitch of the screw thread and, indeed, will vary by a proportion of the pitch of the screw thread that is in relation to the proportion of the angular spacing between two radially extending flat frame sections. Thus, in the event that there are four equally angularly spaced serrated flat frame sections, the serrations on each will vary in axial position successively by a quarter of a pitch at a time. This would mean that it would be important to ensure that the relevant side edges of the frame members are attached in the correct angular positions. In such a case, it is important that identification be associated with each of the frame members, and in particular, physical formations, to ensure that the frame members are attached to each other in the correct relative angular positions. Should any of the connection zones not have a serrated edge, that frame section is shaped so that the connection zone engages the ridges of the screw thread of the connecting collar in the assembled position. The connecting collar will exert enough radial force on the connection zone to ensure that the frame member remains in a secure assembled position. In such a case, identification of the frame members will only be needed if there is more than one serrated connection zone.

The frame itself could be of any appropriate nature and may form part of an item of furnishing such as a lamp base; a lampshade, a cover; or a stand for a tabletop, a chair, a stool or the like.

In order that the invention may be more fully understood, some different embodiments thereof will now be described with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:-

Figure 1 is a perspective view of one embodiment of the invention in the form of a lamp base made up of two frame members each of which has two integral frame sections that cross each other in plan view with the connecting collar being absent;

Figure 2 is the same as Figure 1 but showing the connecting collar in its operative position;

Figures 3 and 4 are elevations of the two frame members showing their shape and co-operating formations for holding the bottom regions in the required relative positions; Figure 5 is a view of a supporting disc for maintaining the connection zones of the frame members in their correct positions for receiving the connecting collar;

Figures 6 and 7 are two elevations of the connection zones taken at 90° to each other and showing the difference in the axial positions of the serrations;

Figure 8 illustrates in elevation two oppositely directed single flat frame members with typical formations and wherein the frame members can be used as a table base in the erected condition;

Figure 9 is an isometric view of a connecting sleeve for interconnecting the lower ends of frame members such as those illustrated in Figure 8;

Figures 10, 1 1 , and 12 are schematic plan views of three different arrangements of flat frame members that can be assembled according to the invention;

Figure 13 is a three-dimensional view of an embodiment of the invention in the form of a lampshade frame in which only one connection zone is serrated; and

Figure 14 is an enlarged and partially exploded view illustrating more clearly the way in which the lampshade frame members are connected to each other in terms of the invention. DETAILED DESCRIPTION WITH REFERENCE TO THE DRAWINGS

In the embodiment of the invention illustrated in Figures 1 to 7, a lamp base is made of two metal plates (1 , 2) that are cut by a computer-controlled laser cutting machine.

Each of the frame members extends from a central assembly axis "A" symmetrically on both sides of the axis in a generally radial direction thereby defining two frame sections per frame member, or a total of four equally angularly spaced frame sections. Each of the frame members has a common transverse base (3, 4) crossing the central assembly axis and one half of which belongs to each of the frame sections of that frame member. Each frame section has an upwardly extending support limb (5, 6) on each side of the assembly axis that follows the contours of a squat bottle to a neck portion that defines connection zones (7a, 7b, 7c, 7d).

Each of the connection zones has a serrated edge (8a, 8b, 8c, 8d) that extends generally parallel to the serrated edges of the other frame sections with the serrations being directed outwards and being located generally on the surface of a circular cross-sectioned cylinder. The serrations are located axially such that all of the sets of serrations lie on a helical path that conforms to an internal screw-thread of a connecting collar (1 1 ) that serves as a fastener to hold the frame sections in their erected condition. The serrations are therefore cut so that serrations that need to cooperate with the internal screw threads on a connecting sleeve are all correctly positioned in the axial direction in the assembled condition.

As regards their lower regions, the two common transverse bases (3, 4) have oppositely directed notches (12, 13) in the centre of the edges so that they can be inter-engaged with the transverse bases crossing each other. The notches serve also to at least partially maintain the frame members in their radially extending relationship relative to each other. Added to this is effect of a supporting disc (15) that serves to locate the connection zones relative to each other from the inside thereof. The supporting disc has notches (16) for receiving the thickness of the frame members on the inside of the connection zones that also have notches (17) for registration with the notches (16) of the supporting disc. The supporting disc serves to restrain the connection zones from moving inwards when the internally screw threaded connecting collar is installed in its position. It also serves to assist in locating the two metal plates axially relative to each other. The result is an extremely firm and effective connection between the frame members.

As mentioned above, the exact axial positions of the apexes of the serrations are highly important in order that they can properly interact with the screw thread of the connecting collar. Figures 6 and 7 illustrate the four different axial positions of the serrations that are each axially offset from those of the next angularly adjacent connection zones. In this embodiment of the invention the two frame members are provided with markings on their transverse bases to ensure that the one frame member is correctly located relative to the other so that the serrations fall on the helical path of the screw thread. Alternatively, the notches in the supporting disc and the inside of the connection zones could be "keyed" to ensure that only one correct position can be selected.

It will be understood that, in order to erect a frame as described above, all that is required is for the two frame members to be located relative to each other by inter-engaging the notches in the transverse bases; properly locating the connection zones relative to the supporting disc; and thereafter installing the internally screw threaded collar.

Another embodiment of the invention in which individual frame members have notches that are key to relative to a common central locating ring is illustrated in Figures 8 and 9. In this embodiment of the invention, six equally angularly spaced individual frame members (20) that each define only one frame section have a lower base member (21 ) having a notch (22) in an edge thereof, typically near a free inner end, that registers with a co-operating notch (23) in a central locating ring (24). The depths of the notches are unique to each frame member so that the edges of the frame members align with the edges of the locating ring only when the correct frame is installed in its correct notch. Any suitable locking means may be provided for locking the frame members in position relative to the locating ring. The upper ends of upright frame sections (25) terminate in supporting upper ends (26) at the upper end of the frame.

Connection zones (27) are provided on the inner ends of radially extending arms (28) positioned in the upper region of each upright frame section and the connection zones could be connected in a manner as described above. The arrangement of six equally angularly spaced individual frame members (20) is illustrated in plan view in Figure 10.

Any other number of frame members could also be used, for example five, providing that each one is uniquely identified and the serrations on the connection zones are correctly positioned axially. Figure 1 1 illustrates an arrangement in which three equally angularly spaced frames (31 ) are connected according to the invention.

Numerous other configurations in which all connection zones have serrated edges are possible. For example, a Tee arrangement in plan view, as illustrated in Figure 12, could be produced in which a frame member having a single frame section (35) is attached to a frame member having two coplanar oppositely directed frame sections (36), for example, for standing close tot a wall.

It is not necessary that each of the frame sections or frame members have a connection zone with serrations and it is within the scope of this invention that as little as one of the connection zones need to have serrations for cooperation with a connecting collar provided that other connector elements are associated with the frame members or sections for maintaining them in their angular and axial positions relative to each other whilst being held captive by the connecting collar.

Figures 13 and 14 show an embodiment of the invention in the form of a lamp shade in which only one of the connection zones has serrations cooperating with the connecting collar in order to located axially. Each frame member (40) extends from a central assembly axis "C" in a generally radial direction. These frame members (40) each has two notches (41 , 42) which co-operate with inter-engaging notches (43, 44) on two axially spaced supporting discs (45, 46). The supporting discs both have central holes to allow a cord (47), typically extending down from a ceiling, to pass through them in order to reach a light bulb (48). A connecting collar (49) encircles connection zones (50, 51 ) of the frame members.

In this embodiment of the invention there are eight frame members but the connection zone of only one connection zone (51 ) is serrated. An interior screw thread of the connecting collar cooperates with the sole serrated connection zone to allow the collar to be held captive relative to the frame members. The connection zones (50) of the other frame members have straight edges that are sized so that the connection zones engage the inner ridges on the internal screw thread (52) of the connecting collar. Interaction between the notches on the frame members and the supporting discs serve to locate the frame members axially relative to each other whilst the serrated connection zone (51 ) of the one frame member (40) restricts axial movement of the collar.

It should be noted that the connection zone off more than one frame member may be serrated but in that instance, the axial positions of the serrations need to be related to the headache of configuration of the screw thread in the connection, as will be quite apparent from the foregoing. Two or more serrated members with the serrations correctly spaced may be employed to provide a more stable structure than one with only a single serrated frame member, if required.

Numerous variations may be made to the embodiments of the invention described above without departing from the scope hereof. It should be noted that the material from which the frame members, connecting collar and/or supporting discs may vary. For example, the frame members and supporting disc may be manufactured from wood, while the connecting collar may be manufactured from metal. Plastics may also be employed.