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FIELD OF THE INVENTION  
         [0001]    This invention relates to a modular building system for freestanding screens or room dividers. Especially the invention relates to a modular building system for freestanding screens of the type used to partition space into discrete areas such as, for example, screens used for partition office space into typing bays and other work areas.  
           [0002]    Freestanding screens or room dividers are frequently formed by integral vertical panels supported vertically by a stand. Such panels may either be solid, for example particle board panels or they may comprise a front panel and a back panel having air space or filling such as insulation between them. Whether the panels are solid or spaced apart panels it is usually necessary for aesthetic purposes to provide an edging around the screen. Sometimes such edging may incorporate linking means to link adjacent panels. The front and back surfaces of such panels may be decorated by any convenient means, frequently by fabric covering.  
           [0003]    Although screens of different heights and widths may be provided by utilizing panels of different sizes, it is not possible to adjust the height of any one particular screen Moreover, although a wide variety of decorative finishing surfaces and side edging may be used, the provision of such finishes adds considerably to the cost of the article. Less importantly, if such screens are to be stored, they take up considerable storage space unless they may be disassembled from their stands. Even if it is possible to disassemble the panels from the stands, the panels must be either stacked vertically against a wall or flat on the floor. In either case considerable floor space or wall space is required for storage.  
         SUMMARY OF THE INVENTION  
         [0004]    The present inventor has attempted to provide a versatile building system for screens, especially those to be used to partition space, which screens may be adjustable in height and easily disassembled for reconfiguration.  
           [0005]    According to the invention there is provided a modular building system to form at least one dissassemblable, freestanding screen, the system comprising at least two elongate supports each having an upper end and a lower end, a foot for each of the support members to hold the support member stably in a vertical position, the lower end of each support member being engagable with one of the feet; a plurality of building blocks stackable one upon another to form a screen. The stacked blocks to be threaded in vertical progression on the support members, each building block comprising a rectangular box having an open bottom and an open top.  
           [0006]    Preferably the building blocks engage one with another by means of members upstanding from opposed inner surfaces of one building block to project into and fit against opposed inner surfaces of another building block stacked on it. The upstanding members may conveniently be formed by profiling upper and lower margins to form interengaging steps. Alternatively inner lining walls may be provided against opposed inner wall surfaces of each building block. Inner lining walls fixed to opposed inner end wall surfaces may be provided with handles to aid manipulation of the building blocks.  
           [0007]    The system may include an uppermost capping member comprising a rectangular box having an open bottom and a closed top the dimensions of the capping member being such as to latch into the building block immediately below it. Preferably, the upper surface of each building block is bevelled downwardly and inwardly. When a capping member is used above one of these building blocks, the dimensions of the capping member may be such that the capping member nests in the building block supported by the bevelled surface.  
           [0008]    The support members may be telescopic so that their height may be adjustable.  
           [0009]    Transverse strut members may be provided within the building blocks to provide them with some rigidity. The building blocks may also be provided with open ended sockets from top to bottom for sliding fit about the support members.  
           [0010]    When assembling a building system according to the invention into a freestanding screen the steps may generally be as follows:  
           [0011]    1) The lower ends of two support members are engaged into corresponding feet;  
           [0012]    2) If the height of the support members is adjustable these are now adjusted to the height required;  
           [0013]    3) A lowermost building block is threaded onto the support members through the sockets in the building block provided for that purpose and the building block is lowered to rest on the feet;  
           [0014]    4) A further building block is threaded onto the support members and lowered onto the lowermost building block;  
           [0015]    [0015] 5 ) Further building blocks are added until the screen has nearly reached the desired height;  
           [0016]    6) The stacked building blocks are retained in the stack by means of engagement means between the uppermost building block and each of the supports;  
           [0017]    7) Finally a capping member is placed over the top end of the support to nest on the uppermost building block. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    Embodiments of the invention will now be described with reference to the drawings in which:  
         [0019]    [0019]FIG. 1 shows a room dividing partition screen made up from a system according to the invention;  
         [0020]    [0020]FIG. 2 shows the room dividing partition screen of FIG. 1 as an exploded view showing details of the building blocks;  
         [0021]    [0021]FIG. 3 is a view of a foot in a building system according to the invention;  
         [0022]    [0022]FIG. 4 shows the interior of a stacking building unit according to the invention; and  
         [0023]    [0023]FIGS. 5 and 6 are engineering drawings of an embodiment of the invention showing preferred features. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0024]    The drawings show a room dividing partition screen  10  made up of building blocks  12  and vertical supports  14 . The screen  10  is a freestanding single unit as shown in FIG. 1. The partition screen  10  comprises building blocks  12  stacked to any desired height.  
         [0025]    As may be best seen from FIG. 2 the system may comprise, for each screen  10 , a pair of elongate support members  14  to be held in a vertical position by feet  16 . Usually a pair of support members  14  with feet  16  is sufficient for any one screen. For example a pair of feet  16  will support a screen of up to 8 feet in width. If a very wide screen is desired, it may sometime be desirable to have more than two support members.  
         [0026]    Feet  16 , illustrated in FIG. 3, may be of any convenient shape and size but generally extend horizontally at right angles to the plane of screen  10  to give it stability in the vertical plane. Conveniently, the feet may have the form illustrated in FIG. 3 being generally elliptical in plan view having a flat lower surface with the major axis of the ellipse extending horizontally at right angles to the plane of the screen. The elliptical base  18  may have a separate round or elliptical neck  20  having a socket  22  in an upper surface. Alternatively the base may be one piece with the neck merging into it. The socket  22  is designed to mate with a lower end of one of the supports  14 . Thus, if the support is of round cross section, then the socket will be of round cross section having a similar diameter. If the support is of square or of other cross section the socket will have a shape corresponding to it.  
         [0027]    The supports  14 , themselves, have a length generally corresponding to the desired height of the screen  10 . In order that the support members  14  lodge securely in sockets of building units  12  in a manner to be hereinafter described, it is desirable that the outer surface of supports  14  be continuous. Thus, supports  14  may be supplied in different lengths according to customer requirements. Alternatively, supports  14  may be supplied in lengths considered adequate for most purposes and may be cut to shorter lengths by the customer if required. Alternatively, supports  14  may be made telescopic but when telescopic supports are provided it may be difficult to provide a continuous outer surface of constant diameter.  
         [0028]    Each building block  12  may comprise a rectangular box having an open top and an open bottom. Each box may be formed of fibre board, chip board, pressed wood, wood or any other convenient material. The boxes or building units  12  may be assembled into the final screen  10  by stacking one box upon another so that the lower edge of one box rests on the upper box of the other. Engagement means should be provided between the boxes to prevent or inhibit relative movement between them. The engagement means may be any convenient means but preferably should be provided inwardly of the boxes so as not to present any unsightly appearance on the outside. For example, as may be seen from FIGS. 2 and 4, the engagement means may be a rigid liner  24  upstanding from an inner surface of a lower box  12  to project into and position an upper box  12  immediately above it. As shown, liners  24  extend fully along both long walls  26  of the box  12 . The liner  24  may only extend over one pair of opposed walls as shown. Alternatively the liner  24  may extend over long side walls  26  and over short end walls  28 . Alternatively, a series of positioning pegs may extend upwardly from the inner surface of a lower box to position an upper box upon it.  
         [0029]    The liners  24  may conveniently comprise elongate boards to rest on ledges  30  projecting inwardly from inner surfaces of long walls  26 . The liners fit loosely against the inner surfaces of long walls  26  and may be prevented from tipping inwardly by rectangular spacer plates  32  extending across each box  12  between the liners  24 . Each spacer plate  32  of the lowermost box  12  rests on the top edge of neck  20  of foot  16 . Each spacer plate  32  of boxes  12  above the lowermost box rest on the spacer plate  32  immediately below it.  
         [0030]    Each spacer plate  32  has an extension  36  having an axially vertical socket therethrough for the passage of elongate vertical supports  14 . Conveniently each extension  36  is a horizontal plate extending from the spacer plate  32 , the horizontal plate  36  having an aperture  34  therethrough, the aperture corresponding in shape to the perimeter of the corresponding support  14 .  
         [0031]    When the liner  24  is a full liner or when it is over opposed short walls  28 , it may be convenient to provide it with handles for easy manipulation of the building units or boxes  12 . These handles may conveniently be formed of apertures in the liner. The liner  24  itself, may be formed from a similar material, i.e. fibre board, chip board, wood, etc, as the outer structure of box  12  or it may be formed of other rigid material capable of locating one box on top of another. Other possible materials are metal sheet, plastic sheet, etc.  
         [0032]    Alternatively as may be seen from FIG. 6, an upper margin of the outer surface of a building block  12  may be profiled by a right angled elongate groove to provide an inwardly stepped, upwardly directed flange  50 . Similarly, a lower margin of a building block  12  may be profiled with an elongate right angled groove to provide a downwardly directed flange or skirt  52  to fit over flange  50 . The arrangement of notches and flanges may be such that the groove and tongue engagement between building units is achieved.  
         [0033]    In assembly, lower ends of supports  14  are nested into sockets  22  of feet  16  and fixed firmly therein. Sockets  22  may be made of distortable plastic material screwed onto foot base  18  by screws  40 . As screws  40  are tightened, neck  20  tends to tighten about support  14 .  
         [0034]    Thereafter, a lowermost building unit or box  12  is slotted onto supports  14  through sockets  22  of plates  36 . The lowermost box  12  is slid down the supports  14  to rest on the upper surface of neck  20  of foot  16 . The dimensions of the upper surface of neck  20  should be sufficiently great to allow box  12  to rest thereon. Spacer plates  32  and liners  24  are placed in position with socket  34  of extension plate  36  about support  14 .  
         [0035]    Thereafter a further box  12  is slotted onto supports  14  and slid down them to rest on the upper edge of the lowermost box  12 . Further liners and spacer plates are added, followed by further boxes  12  as required. When the structure (partition screen  10 ) has nearly sufficient desired height, locking clamps  44  are placed on supports  14  and tightened to hold the boxes  12  in position and allow the screen to be transported as a unit.  
         [0036]    Finally, a cap member is placed over the upper most box  12  to hide the top of supports  14  and the locking clamps  44 . The cap member is generally similar in shape to the boxes  12  but may have a closed top surface  46 .  
         [0037]    Conveniently, each of the boxes  12  may have bevelled upper and lower edges  48 , the bevel extending downwardly and inwardly for vertical nesting engagement of adjacent boxes in a stack. The dimension of cap member  46  may be such that the cap member rests on the bevel to nest slightly within uppermost box  12 . This member cap member  46 , although it rests loosely on the uppermost box  12 , may be retained stably in position by means of this slight nesting.  
         [0038]    The boxes may be painted or otherwise finished according to customer requirements. When not in use they may be stored in any convenient format. If stored on their sides they may even provide convenient storage capacity for other small items.

Summary:
A modular building system is disclosed for forming at least one dissassemblable, freestanding screen, the system comprising at least two elongate supports each having an upper end and a lower end, a foot for each of the support members to hold the support members stably in a vertical position and plurality of building blocks adapted to be threaded in vertical progression on the support members, stackable one upon another to form a screen. There is thereby provided a versatile building system for screens, particularly those to be used to partition room space, which are adjustable in height and easily disassembled for reconfiguration.