Abstract:
An apparatus for inserting, in the molding of picture-frames, metal staples adapted to retain laminar backing elements for pictures, photographs and the like, comprising a beam which is arranged horizontally above the surface that supports the molding, two fixing tools which are guided on the beam transversely to two opposite sides of the molding, an actuation for adjusting the distance between the fixing tools along the beam as a function of the distance between the sides, and a further actuation for vertically actuating the fixing tools into the position for applying metallic staples in the sides.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an apparatus for inserting, in the molding of frames, metal staples adapted to retain laminar supporting elements for pictures, photographs and the like. 
     It is known that in order to frame pictures there are commercially available frames which comprise a rectangular molding formed by assembled strips which are internally provided with a flange which acts as abutment for the glass plate designed to protect the picture to be framed and for a panel of cardboard or the like adapted to support the picture at the rear. In order to retain the panel and the glass plate within the frame, flexible metal staples are inserted behind the panel by means of a mechanical or pneumatic fixing tool which is usually of the manual type. 
     The staples are inserted only partially, so as to have an end which protrudes toward the inside of the frame so that it can be folded back when the panel is to be removed or folded forward again in order to reposition the panel. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to provide an apparatus by means of which the cardboard and the glass plate can be fixed automatically within a picture-frame molding. 
     This aim is achieved with an apparatus for inserting, in the molding of picture-frames, metal staples adapted to retain laminar backing elements for pictures, photographs and the like, characterized in that it comprises a beam which is arranged horizontally above the surface that supports said molding, two fixing tools which are guided on said beam transversely to two opposite sides of said molding, means for adjusting the distance between said fixing tools along said beam as a function of the distance between said sides, and means for vertically actuating said fixing tools into the position for applying metallic staples in said sides. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further characteristics and advantages of the present invention will become apparent from the following detailed description of a preferred embodiment, illustrated only by way of non-limitative example in the accompanying drawings, wherein: 
     FIGS. 1 and 2 are perspective views of the apparatus; 
     FIG. 3 is a front view of the apparatus of FIGS. 1 and 2; 
     FIG. 4 is a view of the head of the fixing tool in the position for inserting the staples in the molding; 
     FIG. 5 is a perspective view of an apparatus provided by combining in an in-line configuration two apparatuses according to FIGS. 1-4 for automatically preparing frames; 
     FIG. 6 is an enlarged-scale view of a detail of the apparatus of FIG. 5; 
     FIG. 7 is a sectional view of a further embodiment of the apparatus. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to FIGS. 1-6, the apparatus is generally designated by the reference numeral  1  and comprises a conveyor for supporting and conveying the frames which is constituted by a belt  2  which is closed in a loop around two rollers  3  and  4 ; the roller  4  is actuated in order to drive the belt with a continuous motion in the direction A. The rollers  3  and  4  are rotatably supported in sides  5  and  6  which rest on the footing  7  by means of spacers  8 . 
     Two vertical posts  9  rise from the side  6  and blocks  10  can slide thereon. Respective stems  11  are guided in the blocks  10  at right angles to the direction A, and a guiding edge  12  is fixed thereto. 
     In this manner, by moving and fixing the blocks  10  on the posts  9  and the stems  11  in the blocks  10  it is possible to adjust the edge  12  vertically and laterally. 
     On the opposite side of the belt  2  with respect to the guiding edge  12  there is another guiding edge  13  which is parallel to the edge  12 . 
     The guiding edge  13  is fixed, in a downward region, to a carriage  14  which is guided on a beam  15  running horizontally and at right angles to the direction A above the belt  2 . 
     The beam  15  cantilevers out from the top of a column  16  which rises from the footing  7  externally with respect to the side  5 . 
     The carriage  14  can be positioned on the beam  15  by means of a drive which comprises a reversible motor  17  which is supported in a cantilevered arrangement by the column  16  and actuates a threaded rod  18  which is engaged in the carriage  14  below the beam  15 . By actuating the rod  18  in one direction or the other it is possible to move the edge  13  closer or further away with respect to the edge  12 , depending on the width of the frame to be prepared. 
     In FIGS. 1-3, the frame comprises a conventional rectangular molding  19  made of wood or other similar material, which is composed by joining at right angles two transverse strips  20  and two longitudinal strips  21 . The strips  20 ,  21  have a cross-section which forms a flange  22  (see FIG. 4) which lies inside the molding  19  and whereon there rest, for example, a glass plate  23  and a rear panel  24 , between which the picture to be framed is to be interposed. The glass plate may of course be omitted and the panel may have any kind of structure. In FIGS. 1-3, the panel that closes the frame to the rear is not shown for the sake of clarity. 
     In addition to the carriage  14 , two sliding blocks  25 ,  26  are slidingly supported on the beam  15 . 
     The sliding block  25  can move along the beam through a transmission system which comprises a threaded stem  27  which lies within a seat of the beam  15  and is actuated by a reversible motor  28 . The stem  27  is rotatably engaged in the sliding block  25 , so that by actuating the motor  28  the sliding block  25  can be moved along the beam  15  in one direction or the other. 
     Two brackets protrude laterally to the beam  15  from the sliding block  25  and two parallel and vertical guiding rods  29  are fixed between them. A slider  30  is slidingly guided on the rods  29 , and a fixing tool  31  of the conventional type is rigidly fixed on said slider. The fixing tool  31  comprises an insertion head  32  (see FIG. 4) which has a nozzle  33  for firing the metal staples to be driven into the molding, said staples being joined so as to form a pack which is accommodated in the magazine  34 . 
     The slider  30  can be raised and lowered along the guiding rods  29  of the sliding block  25  by means of a transmission system which is composed of a reversible motor  35  which actuates a threaded stem  36  which is parallel to the guiding rods  29  and is rotatably engaged in the slider  30 . 
     The sliding block  26  is actuated along the beam  15  exactly like the sliding block  25  by means of a reversible motor  37  and a threaded stem (not shown in the drawing) which is actuated by the motor  37  and engages the sliding block  26  with a screw-type coupling. 
     The sliding block  26  also supports a fixing tool  38  which is fitted on a slider which can be positioned vertically by means of a transmission system which is fully identical to the transmission system that actuates the slider  30  and is actuated by a reversible motor  39 . Only the motor  39  of said transmission system is shown in the drawing; said motor actuates, by means of the threaded stem, the lifting of the slider on which the fixing tool  38  is fitted. 
     The fixing tools  31 ,  38  are orientated so that by descending from a raised position by means of the motors  35 ,  39  the nozzles of said fixing tools are directed toward the internal face  40  of the longitudinal strips  21  of the molding, above the rear panel  24 . 
     The operation of the above-described apparatus is as follows. 
     Assume an initial position in which the guiding edge  13  is already arranged, with respect to the opposite guiding edge  12 , at a distance which allows to guide the molding  19  between them without appreciable transverse plays with respect to the advancement direction A. Assume, furthermore, that the nozzles of the fixing tools  31 ,  38  are vertically aligned on the internal flanges  22  of the longitudinal strips  21  and are raised with respect to the level of the belt  2 , so as to allow the molding  19  to pass below them. 
     In this situation, when a molding  19  has been conveyed by the belt  2  until it reaches the position in which the fixing tools  31  are arranged inside the molding, the motors  35  and  39  are activated so as to lower the sliders  30  to a level at which the nozzles  33  of the fixing tools  31 ,  38  are engaged in the corner formed by the panel  24  and by the internal face  40  for containing the panel  24  on the flange  22 . 
     At this point, the fixing tools  31 ,  38  are activated and drive the staples into the longitudinal strips  21 , thus locking said panels  24  against the flange  22  with the glass plate  23  interposed. Once this step for the insertion of the metal staples has been completed, the fixing tools  31 ,  38  are again raised above the molding  19 , so as to allow it to continue further. A prerogative of the present invention is the fact that the arrangement of the fixing tools  31 ,  38  at the level for inserting the staples can be achieved by means of adapted sensors which, after detecting the presence of the molding  19  on the belt  2 , actuate the gearmotors  35 ,  39  so as to lower the fixing tools  31 ,  38 . 
     In a preferred embodiment of the invention, conceived in order to adapt the apparatus to the width of the moldings, particularly when it is necessary to work with molding of different sizes, provisions are made for the use of additional sensors which are capable of detecting the transverse dimensions of the moldings  19  conveyed by the belt  20  and to accordingly actuate the gearmotors  17 ,  28 ,  37  so as to adapt the distance between the guiding edges  13  and  12  to the width of the molding as detected by the sensors and move the sliding blocks  25 ,  26  so as to achieve the vertical alignment of the nozzles of the fixing units  31 ,  38  on the flanges  22  at the longitudinal strips  21 . 
     The above-described apparatus can be operatively associated with another identical one in order to produce a unit which allows to insert metal staples on all the sides of the molding. 
     For this purpose, as shown in FIG. 5, at the outlet of the belt  2  of a first apparatus  1  there is a turntable  41  which is capable of turning through 90° the moldings transferred onto it by the belt  2 . Advantageously, the turntable  41  is constituted by a plurality of belts  42  (see FIG. 6) which are closed in a loop around corresponding pulleys and whose upper portion forms a supporting surface for the moldings  19  that arrive from the belt  2 . The belts are actuated with a decreasing motion from one side to the other, so as to turn through 90° the molding that rests temporarily on them, so that the longitudinal strips  21  arrange themselves transversely to the advancement direction A. Downstream of the turntable  41  there is a second apparatus  1 ′ which inserts the metal staples on the transverse strips  20 , which are now longitudinal. At the output of the second apparatus  1  there is a conveyor  43  which removes the completed moldings. Optionally, instead of the conveyor  43  it is possible to provide an additional turntable in order to return the moldings to the initial arrangement. 
     FIG. 7 is a sectional view of a further embodiment of the invention, in which the lifting and lowering of the slider  30  by means of the threaded stem  36  is combined with the movement actuated by a pneumatic cylinder  42   a.    
     For this purpose, the threaded stem  36  is screwed into a tube  43  which is guided axially, but retained rotationally, through a cylindrical cavity  44  formed in the slider  30 . A piston  45  is rigidly coupled on the tube  43  and divides the cavity  44  into two chambers. By feeding compressed air to the upper or lower chamber, the slider  30  is made to rise or descend, respectively. This allows to use the motors  35 ,  39  for molding size changes and the pneumatic cylinders for raising and lowering the fixing tools during normal working conditions. 
     In practice, the turntable  41  is provided with guiding edges in order to facilitate and improve the precision of the rotation of the moldings in transit. 
     Advantageously, the speed at which the frames move on the turntable is at least twice the speed with which the frames advance on the conveyor of the apparatuses for inserting the fixing elements, in order to allow correct mutual spacing of the frames and their rotation through 90°. 
     The disclosures in Italian Patent Application No. BO99A000013 from which this application claims priority are incorporated herein by reference.