Abstract:
Tubular fold-away legs for support surfaces which includes a joint, which is made up of an element for coupling to the tubular body and an attachment element to said support surface, the legs being mobile between a first closed non-operative position and a second open operative position, tilted by an angle with respect to the support surface. The joint is equipped with elastic locking device to secure it in either the non-operative or operative positions and with a stable attachment device when in the operative position, as well as matching tilted centering surfaces.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not Applicable 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable 
   INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK 
   Not Applicable 
   REFERENCE TO A MICROFICHE APPENDIX 
   Not Applicable 
   The present invention refers to fold-away legs for support surfaces, in particular to tubular legs. 
   BACKGROUND OF INVENTION 
   In the field of tables there is a great need to fold the legs towards the surface to allow, for example, piles of tables to be transported with less bulk. Fold-away legs can also be applied more generally to all furniture made up of a support surface supported, indeed, by such legs. 
   Nevertheless, particularly in the field of tables to be used in meetings, restaurants or group meeting halls, which must frequently be set up or removed and the put back, it is suitable to have fold-away legs which are easy to maneuver, suitable for allowing many tables to be piled up. Stability of the support surface and a good aesthetic result are non-negligible elements. 
   Currently, the market offers fold-away legs included in complex structures hinged below the support surfaces. Other structures, besides frequently having a non-negligible bulk, are equipped with complicated leverages to be actuated both in the opening and closing step. 
   Frequently, moreover, fold-away structures associated with legs for support surfaces, currently on the market, significantly weigh down the furniture. 
   &lt;Tubular fold-away legs for support surfaces representing the closest state of the art of the present invention are known from documents CH--A-690641 and US-A-3491706 and comprise a joint provided with an helicolidal spring which is housed inside of the joint and exerts its force in an axial direction to maintain complementary surfaces of the joint in engagement one inside the other.&gt; 
   BRIEF SUMMARY OF THE INVENTION 
   The general purpose of the present invention is that of overcoming the aforementioned drawbacks of the prior art in an extremely simple, cost-effective and particularly functional manner. 
   Another purpose is that of realising fold-away legs for support surfaces with good stability and above all with fast and easy manoeuvrability. 
   A further purpose is that of realising fold-away legs which are easy to attach to the surface of the table and adaptable to whatever shape and size of the surface itself. 
   In view of the aforementioned purposes, according to the present invention, it has been thought of to realise fold-away legs, having the characteristics outlined in the attached claims. 
   The structural and functional characteristics of the present invention and its advantages compared to the prior art shall become clearer from an examination of the following description, referring to the attached drawings, which show fold-away legs realised according to the innovative principles of the invention itself. 
   In the drawings: 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       FIG. 1  is an exploded view of a fold-away leg object of the present invention; 
       FIG. 2  shows fold-away legs according to the invention applied to a support surface and locked in non-operative and operative position; 
       FIG. 3  is a partial section view from above of the fold-away leg of  FIG. 1 ; 
       FIG. 4  is a side elevation partial section view of the fold-away leg; 
       FIGS. 5-11  schematically show the closing steps of fold-away legs, object of the present invention, and the corresponding section views of the elastic locking means; 
       FIG. 12  shows support surfaces piled on top of each other, equipped with fold-away legs in non-operative position; 
       FIG. 13  is a side elevation view of a fold-away leg in closed position. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   With reference to the drawings, fold-away legs for support surfaces in object are wholly indicated with  10 , and in the illustrated example, according to the present invention, comprise a tubular body  12  and a joint  13  for articulated coupling with a support surface  14 . 
   The joint  13  consists of an element for coupling with the tubular body  15 , for example a sleeve on which such a tubular body  12  is slotted with light interference, and an attachment element  16  to the support surface  14 , pivoted together through a rod or through-pin  17  ( FIG. 1 ). 
   The articulated joint  13  allows legs  10  to be mobile between a first closed non-operative position A and a second open operative position B ( FIG. 2 ). 
   In the closed non-operative position the tubular body  12  of the legs is arranged in a position substantially aligned with the support surface  14 , so as to minimise the bulk. 
   In the open operative position the tubular body  12  is tilted by an angle α with respect to the support surface  14 . In the embodiment shown only as an example and not for limiting purposes, the support surface  14  and the tubular body  12  are arranged at a right angle. 
   In further embodiments which are not shown the legs  10  could be angled differently in operative position with respect to the support surface  14 . 
   The attachment element  16  to the support surface comprises an attachment plate  18 , equipped for example with a plurality of holes  19  for screwing into the support surface. Alternatively, the plate  18  could be fixed differently to the support surface. 
   From the attachment plate  18  a guide wall  20 , for the rotation of the sleeve  15  with respect to the plate  18 , extends in a normal direction with respect to a plane of rotation  11  of the fold-away leg  10 . 
   In the guide wall  20 , in a substantially central position near to the plate  18 , a through hole  21  is formed for the insertion of the rotation pin  17 . 
   In the plane of rotation  11 , the guide wall  20  has a bevelled profile  22 . At one end two wedge-shaped elements  23  extend laterally, which identify tilted centring surfaces with the sleeve. 
   The guide wall  20  is also equipped with seats or recesses  24   a,    24   b  for the intervention of elastic locking means  25 , which prevents the relative rotation between sleeve  15  and plate  18  when the leg is respectively in open operative position B ( FIG. 3 ) and in closed non-operative position A. 
   The seats  24  are arranged in pairs which mirror each other with respect to the plane of rotation  11  on both of the faces of the guide wall  20 . 
   The sleeve  15 , coupled with the tubular body  12 , is internally hollow and equipped with tilted inner surfaces  26  which match the wedge-shaped elements  23  of the plate  18 , to realise a stable coupling with light interference ( FIG. 4 ). 
   The matching surfaces  23  and  26  of the joint  13  constitute stable attachment means of the tubular body  12  to the support surface  14  in open operative position. 
   The sleeve  15  is equipped with an opening, from which a forked element  28  extends outwards, on which a hole  29  is realised aligned with the hole  21  of the guide wall  20  for the insertion of the rotation pin  17 . 
   On the fork  28  a pair of through seats  30  are also realised, which are symmetrical with respect to the plane of rotation  11 , which receive the elastic locking means  25 , like, for example, an elastic U-bolt, consisting of a U-shaped metal sheet. 
   The U-bolt  25  comprises two side arms  31  and a concave pressing surface  32 , on which the user intervenes. 
   The arms  31  each carry, at their ends, engagement means  33 , for example consisting of trapezoidal fins, symmetrical with respect to the plane of rotation  11 . 
   The fins  33 , housed in the through seats  30  of the forked element  28 , alternately engage, when the leg is in open or closed position, in one of the pairs of seats  24   a  or  24   b  of the guide wall  20  of the attachment plate  18 . 
   The pressure applied on the concave surface  32  of the elastic U-bolt  25  determines a spreading movement of the arms  31  carrying the fins  33 , promoted by the presence of tilted planes  34  formed in the through seats  30  and matching outlet edges  35  of the fins  33 . 
   The sleeve  15  is also equipped with a perimetric collar  36  which, in a position diametrically opposite with respect to the forked element  28 , forms an abutment surface  37  for the piling of support surfaces  14  equipped with legs  10  in folded-away position (FIG.  13 ). 
     FIGS. 4 and 5  show a fold-away leg  10 , object of the present invention, in open operative position, made stable by the forced coupling between the matching tilted centring surfaces  23  and  26 , and the curved surface  23 A. 
   The leg  10  is held in such a position by the elastic locking means  25 , engaged in the pair of seats  24   b  of the plate  18  ( FIG. 6 ). 
   The pressure applied on the U-bolt  25  in the direction of the arrow F, induces the sliding of the fins  33  on the tilted planes  34  of the through seats  30  of the sleeve  15 , until their disengagement from the seats  24   b  of the attachment element  16  is caused ( FIG. 7 ). 
   In this situation the user can freely rotate the sleeve  15  with respect to the plate  18  to fold the leg  10  towards the support surface  14 , as represented with the arrow R in  FIG. 8 . 
   During the rotation it is possible to release the pressure on the U-bolt  25 , since the fins  33  abut against the outer surface of the guide wall  20  and thus keep the arms  31  of the elastic U-bolt  25  spread ( FIG. 9 ). 
   Once the position in which the fins  33  are aligned with the second pair of seats  24   a  of the plate  18  is reached, through the elastic return force applied by the deformed U-bolt  25 , the fins  33  automatically engage in the seat  24   a,  as schematised in  FIG. 11 , holding the leg  10  in the non-operative position of  FIG. 10 . 
   The opening steps of the fold-away leg  10 , object of the present invention, proceed in a totally analogous way to that which has already been described. 
   Once the U-bolt has been unhooked through pressing, the leg is rotated up to its stable attachment in open operative position at a right angle with respect to the support surface. 
   The attachment plates  18  can advantageously be fixed to the support surface  14 , in a position such as not to cause interference between the legs  10  when folded in non-operative position, as represented in  FIG. 12 . 
   Moreover, both the element for coupling with the tubular body of the leg  15 , i.e. the sleeve, and the attachment element to the surface  16 , can advantageously be made both from metal and from plastic. In such a way a joint  13  which is particularly light and cost-effective is obtained. 
   The fold-away legs for support surfaces, object of the present invention advantageously allow tables to be piled up avoiding possible damage, such as scratching, of the surfaces. 
   Indeed, in non-operative position the presence of an abutment surface made from plastic allows safe piling of tables. 
   Another relevant advantage of the fold-away legs according to the invention is that the joint  13  and the relative components are all contained within the leg. 
   From that which has been described above with reference to the figures, it is clear how fold-away legs for support surfaces according to the invention are particularly useful and advantageous. The purpose mentioned in the preamble of the description is thus accomplished. 
   Of course, the shapes of the fold-away legs of the invention can be different from those shown as a non-limiting example in the drawings, just as the materials can also be different. 
   The scope of protection is therefore defined by the attached claims.