Abstract:
This museum showcase comprises a load-bearing frame comprising tubular beams with quadrangular section connected together by at least one joint, and is characterized in that the joint comprises two flat and parallel plates, wherein each plate comprises a middle portion and at least two attachment wings, wherein the two attachment wings of each plate are respectively inserted in a first and a second of the tubular beams and fixed to them. In this way, the showcase can be designed and built in a particularly quick and easy manner. Both the beams and the joints can be made starting from extremely simple and cost-effective semi-finished products (tubes and plates, respectively), with elementary processes, basically simple cuts to the desired sizes.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to Italian Application No. UA2016A004705 filed on Jun. 28, 2016, which is incorporated herein by reference in its entirety. 
       FIELD 
       [0002]    The present invention relates to a museum showcase, i.e. a showcase intended to be placed in a display place such as a museum, an exhibition or the like and intended for the preservation and display of objects of cultural heritage, such as works of art, historical artefacts and the like, in a protected environment. The term showcase will be sometimes used hereinafter for the sake of brevity, by this however always meaning a museum showcase. 
       BACKGROUND 
       [0003]    Showcases of this type must meet various requirements, in relation to the preservation and integrity of the exhibits. In particular, they should normally ensure a high level of security with respect to possible attempts of unauthorized opening or tampering, as well as ensure adequate insulation between the inner and outer environment. It is also appropriate that these showcases have a structure such as to facilitate the production processes. 
         [0004]    To this end, manufacturers of showcases use metal materials—typically aluminium and iron—to manufacture support structures, such as a load-bearing frame and/or a showcase base; the fixed and opening walls of the showcase, typically made of transparent material, are mounted on these support structures. Normally, the transparent material used is glass. 
         [0005]    In particular, showcases have been developed with a base surmounted by a case formed by the walls; the base houses the technical components of the showcase and is therefore normally closed by non-transparent walls to block the view of such components; in contrast, the walls of the case are wholly or largely transparent to allow viewing of the exhibits. 
         [0006]    The frame is normally made with beams welded together and then painted. In this way, a frame can be achieved having the strength required to adequately support all the transparent walls (whose weight can be very large, in large-sized showcases) and as well as any other element or accessory of the showcase. 
         [0007]    The Applicant has realized that structures of this type are relatively complex to be made. 
         [0008]    The present invention therefore raises the problem of facilitating the construction of the showcase. 
       SUMMARY 
       [0009]    Accordingly, the present invention relates to a showcase as defined in claim  1 . Preferred features are described in the dependent claims. 
         [0010]    More particularly, a museum showcase according to the invention has a load-bearing frame comprising tubular beams with quadrangular section connected together by at least one joint, and is characterized in that the joint comprises two flat and parallel plates, wherein each plate comprises at least two attachment wings, wherein the two attachment wings of each plate are respectively inserted in a first and a second of the tubular beams and fixed to them. 
         [0011]    In this way, the showcase can be designed and constructed in a particularly easy and therefore quick manner, selecting the number and size of the tubular beams according to the size of the showcase and the weight of the walls and connecting the tubular beams together with the necessary number of joints, particularly simple. Both the beams and the joints can be made starting from extremely simple and cost-effective semi-finished products (tubes and plates, respectively), with elementary processes, basically simple cuts to the desired sizes. In particular, once the beam section dimension has been defined, it is very easy to make the joints required, sizing the plates according to the size of the beam section. 
         [0012]    However, it is also possible to easily define standard sizes for beams and joints, so as to use the same joints for showcase even very different in size, the size of the showcase imposing only the use of horizontal beams of different lengths. 
         [0013]    Moreover, this structure allows easy and quick assembly of the showcase, as well as an equally quick and easy disassembly thereof. The quadrangular (square or rectangular) section of the tubular beams promotes the strength of the connections by means of the joints, since the plates of the joints can completely rest on the flat inner walls of the tubular beams, thus being able to transmit the mechanical strains in the best possible manner. 
         [0014]    Preferably, the joint also comprises an attachment block having a parallelepiped shape, fixed to a first of the two plates on the opposite side with respect to the second of the two plates inserted in a third of the tubular beams of the frame, different from the first and second tubular beams in which the attachment wings are inserted and fixed, and fixed to the third of the tubular beams. In this way, it is possible to make joints with three directions (such as corner joints): in two mutually coplanar directions, the beams are connected to the joint by the attachment wings, in the third direction by the attachment block. The construction is still quick and easy. 
         [0015]    Preferably, the joint also comprises a spacer block with parallelepiped shape, arranged between the plates and fixed to them. Such a spacer block imparts additional strength to the joint and thereby to the frame, by directly connecting the two plates together and effectively preventing any torsional or flexural deformation of the joint. 
         [0016]    Preferably, the attachment block has a section matching the internal section of the tubular beams, so as to be able to insert therein with forcing or with minimal clearance. In this way, the connection of the joint to the third tubular beam is particularly strong and sturdy. 
         [0017]    The attachment between parts of the joint and between the joint and the tubular beams can be accomplished in various ways, for example by means of screws. Preferably, therefore, the joint comprises first attachment screws, inserted in through holes in the first and second beams and screwed into threaded holes formed in the attachment wings of the plates; these screws ensure a solid connection between the tubular beams and the joint plates. Preferably, the joint comprises a second attachment screw, inserted in a through hole in the middle portion of the first plate and screwed into a threaded hole formed in the attachment block; this screw (a single screw or more screws) ensures a solid connection between the attachment block and the joint plate. Preferably, the joint comprises a third attachment screw, inserted in a through hole in the third beam and screwed into a threaded hole formed in the attachment block; this screw (a single screw or multiple screws) ensures a solid connection between the attachment block and the third beam. Preferably, the joint comprises a fourth attachment screw, inserted in a through hole in the middle portion of a plate and in a through hole of the spacer block and screwed into a threaded hole formed in the middle portion of the other plate; this screw (a single screw or multiple screws) ensures a solid connection between the two plates and the spacer block. 
         [0018]    Preferably, the spacer block and the middle portions of the plates attached to it are outside of the tubular beams, abutting at ends thereof. This allows sizing these elements so that the joints have sizes according to the size of the beams, thus preventing potentially dangerous and aesthetically unpleasing protruding edges. 
         [0019]    A joint according to the invention, as said, comprises at least two attachment wings but it may also comprise three or four. With three attachment wings, the joint can connect two tubular beams mutually opposite at 180° and a beam at 90° (T configuration); with four attachment wings, the joint can connect four tubular beams mutually at 90°, two by two opposite at 180° (cross configuration). The possible presence of an attachment block allows the joint to connect a further tubular beam, orthogonal to the plane of the three or four tubular beams connected to the attachment wings. 
         [0020]    Preferably, the joint comprises two attachment blocks having a parallelepiped shape, fixed to a middle portion of a respective one of the two plates on the opposite side with respect to the other of the two plates, inserted in a third and a fourth of the tubular beams of the frame, different from the first and second tubular beams in which the attachment wings are inserted and fixed, and fixed to the third and fourth of the tubular beams. In this way, it is possible to make joints with four or more directions (e.g., intermediate joints in a complex frame structure): in two or more mutually coplanar directions, the tubular beams are connected to the joint by the attachment wings, in the two directions orthogonal to such a plane, the tubular beams are connected to the joint by the attachment block. The construction is still quick and easy. 
         [0021]    Preferably, the plates comprise abutment seats for the tubular beams, formed between the attachment wings and a middle portion, so that the middle portion cannot enter inside the tubular beams. This feature not only facilitates the precise fitting of the parts but also improves the transmission of strains between the tubular beams and the joint. 
         [0022]    The tubular beams and the parts of the joints can be made of various materials. Preferably, they are made of aluminium, thus being lightweight, resistant, easy to be drilled and cut to size, cost-effective (they are available in standard sizes on the market). Preferably, the tubular beams and/or the attachment blocks and/or the spacer blocks are made of aluminium, thus being lightweight, durable, easy to be drilled and cut to size, cost-effective (they are available in standard sizes on the market); moreover, their exterior finish is excellent with no need to apply paints of any kind. Preferably, the plates are made of sheet iron or steel; although obviously being heavier and less easy to machine than aluminium, sheet iron or steel is preferred in this case to ensure the best resistance to deformation to the plates. 
         [0023]    In a preferred embodiment, the plates are completely inserted into the beams tubular, cut at 45°; this structure has the advantage of completely hiding the plates inside the beams. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0024]    Further features and advantages of a museum showcase according to the present invention will appear more clearly from the following description of some preferred embodiments thereof, made with reference to the accompanying drawings. In such drawings: 
           [0025]      FIG. 1  is a schematic perspective view of a showcase according to the invention; 
           [0026]      FIG. 2  is a schematic perspective view of a part of the frame of the showcase in  FIG. 1 ; 
           [0027]      FIG. 3  is an enlarged scale view of a joint of the frame in  FIG. 2 ; 
           [0028]      FIG. 4  is an exploded view of the joint in  FIG. 3 ; 
           [0029]      FIG. 5  is an exploded view of a joint similar to the joint in  FIGS. 3 and 4 , adapted to connect only two beams; 
           [0030]      FIG. 6  is an exploded view of a joint similar to the joint in  FIGS. 3 and 4 , adapted to connect six beams; 
           [0031]      FIG. 7  is a schematic perspective view of part of the frame in  FIG. 1 , according to a different embodiment of the invention; 
           [0032]      FIG. 8  is an enlarged scale view of a joint of the frame in  FIG. 7 ; 
           [0033]      FIG. 9  is an exploded view of the joint in  FIG. 8 ; 
           [0034]      FIG. 10  is an enlarged scale view of a joint similar to the joint in  FIGS. 8 and 9 , adapted to connect only two beams; 
           [0035]      FIG. 11  is an exploded view of the joint in  FIG. 10 . 
       
    
    
     DESCRIPTION 
       [0036]      FIG. 1  schematically shows a showcase  10  according to the invention. Showcase  10  comprises a frame  11 ,  3  fixed walls  12  and an opening wall  13 , which are all supported by the load-bearing frame  11  and define an exhibit space S of showcase  10 . 
         [0037]    Frame  11  of showcase  10  is shown in  FIG. 2 . Frame  11  comprises tubular beams  20  with quadrangular section (in particular, square) connected together by joints  30 , one of which is better shown in  FIGS. 3 and 4 . 
         [0038]    Joint  30  shown connects three tubular beams  20  together, arranged at 90° each one with respect to the plane of the others, i.e. according to three classical orthogonal axes X, Y, Z. Joint  30  comprises two plates  31  and  32 , flat and parallel to each other according to the plane defined by axes XY. Plates  31  and  32  are substantially L-shaped, with respective middle portions  33  and  34  and two attachment wings each: one wing  35  and one wing  37  of plate  31 , one wing  36  and one wing  38  of plate  32 . Wings  35  and  36  are directed according to axis X, while wings  37  and  38  are directed according to axis Y. 
         [0039]    The attachment wings  35  and  36  are inserted in a first one of the tubular beams  20 , also indicated with reference numeral  20   a , oriented according to axis X; the attachment wings  37  and  38  are inserted in a second one of the tubular beams  20 , also indicated with reference numeral  20   b , oriented according to axis Y. The attachment wings— 38  are attached to the respective tubular beams  20   a ,  20   b  by means of first attachment screws  41 , inserted in through holes  42  formed in the tubular beams  20   a ,  20   b  and screwed into threaded holes  43  formed in the attachment wings  35 - 38 . In frame  11  shown, two attachment screws  41  are provided for each of the attachment wings  35 - 38 . It is noted that the attachment wings  35 - 38  are perfectly lying along opposite inner walls of the tubular beams  20 , due to the quadrangular section of the latter. 
         [0040]    Joint  30  also comprises an attachment block  50 , with parallelepiped shape, attached to the middle portion  33  of plate  31 , opposite to plate  32 . The attachment block  50  has a section matching the internal section of the tubular beams  20 , so as to be able to insert therein with forcing or with minimal clearance. The attachment block  50  is inserted in a third one of the tubular beams  20 , oriented according to axis Z and also indicated with reference numeral  20   c , different from the tubular beams  20   a  and  20   b  in which the attachment wings  33 - 38  are inserted and attached. The attachment block  50  is fixed to plate  31  by means of a second attachment screw  51 , inserted in a through hole  52  formed in the middle portion  33  of plate  31  and screwed into a threaded hole  53  formed in the attachment block  50 . Moreover, the attachment block  50  is fixed to beam  20   c  by means of a third attachment screw  55 , inserted in a through hole  56  formed in beam  20   c  and screwed into a threaded hole  57  formed in the attachment block  50 . 
         [0041]    The two plates  31  and  32  are mutually spaced apart and a spacer block  60 , with parallelepiped shape, is arranged between them. The spacer block  60  is attached between the middle portions  33  and  34  of the two plates  31  and  32  by means of the same screw  51  which, in addition to the through hole  52 , crosses a through hole  62  formed in the middle portion  34  of plate  32  and another through hole  63  formed in the spacer block, as clearly seen in  FIG. 4 . 
         [0042]    The spacer block  60  and the middle portions  33  and  34  of plates  31  and  32  attached to it are outside of the tubular beams  20 , abutting at ends thereof. 
         [0043]    Plate  31  and  32  also comprise abutment seats, all indicated with reference numeral  39 , for providing a support to the ends of the tubular beams  20 . The abutment seats  39  are formed between the attachment wings  35 - 38  and the respective middle portions  33  and  34 , so that the latter cannot enter inside the tubular beams  20 . 
         [0044]    In frame  11 , joints  30  connect the three tubular beams  20   a ,  20   b ,  20   c  together. In a showcase according to the invention, however, there may also be portions of frame in which there are only two tubular beams, as shown in  FIG. 5 . Joint  130  shown in  FIG. 5  is completely similar to joint  30  just described, except that it is lacking the attachment block, since it does not need to connect any beam in direction Z. The elements of joint  130  are therefore substantially identical to those of joint  30  and are not described herein, while in  FIG. 5 , the same reference numerals used for joint  30  are used; the only difference is screw  151 , which is inserted in through holes  62  and  63  and is screwed into a threaded hole  152  formed in the middle portion  33  of plate  31 . 
         [0045]    In a showcase according to the invention, there may also be portions of frame in which there are multiple tubular beams, such as six tubular beams, as shown in  FIG. 6 . Joint  230  shown in  FIG. 6  is similar to joint  30  described above, however, it has two attachment blocks and plates with four attachment wings. The elements of joint  230  therefore are substantially identical to those of joint  30  and are not described herein, while in  FIG. 6 , the same reference numerals used for joint  30  are used, except for the different parts described hereinafter. 
         [0046]    Joint  230  can connect four tubular beams  20   a ,  20   b ,  20   d ,  20   e  at 90° with respect to one another, two by two opposite at 180° and two tubular beams  20   c ,  20   f , opposite at 180° with respect to each other and orthogonal to the plane of the four tubular beams  20   a ,  20   b ,  20   d ,  20   e . To this end, joint  230  comprises two plates  231  and  232  each with four attachment wings,  35 ,  35   a ,  37 ,  37   a  and respectively  36 ,  36   a ,  38 ,  38   a ; these attachment wings are fixed to the tubular beams in a totally identical manner to what was seen for joint  30 . Moreover, joint  230  comprises two attachment blocks  50  and  50   a , opposite at 180° and fixed to plates  231  and  232 ; these attachment blocks are fixed to the plates and to the tubular plates in the same manner as provided for joint  30 , i.e. by means of screws, except that screws  251 ,  251   a  are arranged in an opposite manner with respect to joint  30 , i.e. they pass in through holes  253 ,  253   a  formed in the attachment blocks  50 ,  50   a  and are screwed in threaded holes  252 ,  252   a  formed into the middle portions  33 ,  34  of plates  231 ,  232 . In joint  230 , there is no spacer block between plates  231  and  232 , which therefore are integral E with each other through the attachment to the tubular beams  20 . 
         [0047]      FIG. 7  shows a different embodiment of frame  311  of showcase  10 . Frame  311  comprises tubular beams  320  with quadrangular section (in particular, square) connected together by joints  330 , one of which is better shown in  FIGS. 8 and 9 . 
         [0048]    Joint  330  shown connects three tubular beams  320  together, arranged at 90° each one with respect to the plane of the others, i.e. according to three classical orthogonal axes X, Y, Z. Joint  330  comprises two plates  331  and  332 , flat and parallel to each other according to the plane defined by axes XY. Plates  331  and  332  are substantially L-shaped, with respective attachment wings each: one wing  335  and one wing  337  of plate  331 , one wing  336  and one wing  338  of plate  332 . Wings  335  and  336  are directed according to axis X, while wings  337  and  338  are directed according to axis Y. 
         [0049]    The attachment wings  335  and  336  are inserted in a first one of the tubular beams  320 , also indicated with reference numeral  320   a , oriented according to axis X; the attachment wings  337  and  338  are inserted in a second one of the tubular beams  320 , also indicated with reference numeral  320   b , oriented according to axis Y. The attachment wings— 338  are attached to the respective tubular beams  320   a ,  320   b  by means of first attachment screws  341 , inserted in through holes  342  formed in the tubular beams  320   a ,  320   b  and screwed into threaded holes  343  formed in the attachment wings  335 - 338 . In frame  311  shown, two attachment screws  341  are provided for each of the attachment wings  335 - 338 . It is noted that the attachment wings  335 - 338  are perfectly lying along opposite inner walls of the tubular beams  320 , due to the quadrangular section of the latter. 
         [0050]    Joint  330  also comprises an attachment block  350 , with parallelepiped shape, attached to plate  331 , opposite to plate  332 . The attachment block  350  has a section matching the internal section of the tubular beams  320 , so as to be able to insert therein with forcing or with minimal clearance. The attachment block  350  is inserted in a third one of the tubular beams  320 , oriented according to axis Z and also indicated with reference numeral  320   c , different from the tubular beams  320   a  and  320   b  in which the attachment wings  333 - 338  are inserted and attached. The attachment block  350  is fixed to plate  331  by means of a second attachment screw  351 , inserted in a through hole  352  formed in the attachment block  350  and screwed into a threaded hole  353  formed in plate  331 . Moreover, the attachment block  350  is fixed to beam  320   c  by means of two third attachment screws  355 , inserted in respective through holes  356  formed in beam  320   c  and screwed into respective threaded holes  357  formed in the attachment block  350 . 
         [0051]    The two plates  331  and  332  are mutually spaced apart and a spacer block (similar to block  60 ) may optionally be arranged between them; in joint  330  shows there is no spacer block. 
         [0052]    Plates  331  and  332  are fully inserted into the corresponding beams  320  (having no intermediate portion similar to the intermediate portions  33 - 34  of joint  30 ). The tubular beams  320   a  and  320   b  have ends cut at 45° so as to abut on each other, thereby completely hiding plates  331  and  332  from view; in contrast, beam  320   c  has ends cut at 90°, having to abut to the side of beams  320   a  and  320   b . It is noted that a hole (not shown in figure) is formed on the side of these beams for the passage of screw  351 . 
         [0053]    In frame  311 , joints  330  connect the three tubular beams  320   a ,  320   b ,  320   c  together. In a showcase according to the invention, however, there may also be portions of frame in which there are only two tubular beams, as shown in  FIGS. 10 and 11 . Joint  430  shown in  FIGS. 10 and 11  is completely similar to joint  330  just described, except that it is lacking the attachment block, since it does not need to connect any beam in direction Z. The elements of joint  430  therefore are substantially identical to those of joint  330  and are not described herein, while in  FIGS. 10 and 11 , the same reference numerals used for joint  330  are used. 
         [0054]    Of course, other configurations are possible, while not departing from the scope defined by the following claims. In particular, joints may be provided in which the plates have any a number of attachment wings from two to six, and/or in which zero to two attachment blocks are provided, in any combination. Moreover, depending on the circumstances and the strength requirements, a spacer block may be or not provided between the two plates. The tubular beams may have ends cut at 45° or 90°.