Abstract:
Process for producing tubular shaped pieces ( 105 ) having a rectangular cross section of low height, to transform electric current into diffused heat, by means of pultrusion, with continuous formation, added to known reinforcing materials such as roving ( 60 ) and mats ( 65 ) of fibreglas, on one broad side of the shaped piece ( 105 ), of one or more parallel nets ( 72, 73 ) of a weft woven ( 80, 81 ) fabric made from a continuous wire ( 77 ) of highly conductive material coated with insulating material ( 78 ), connected at set intervals to devices ( 111, 112 ) of electric sockets incorporated in the plastic material ( 50 ) so that, when the shaped piece ( 105 ) is cut through at the position of the devices ( 111, 112 ) to form electric sockets, and by filling the panels with insulating foam material ( 145 ) oblong panels ( 116 ) are obtained utilizable for innumerable purpose

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns appliances for transforming electric current into diffused heat. 
     The pultrusion process is well known, being one that produces parts of a certain shape possessing mechanical characteristics of a high order by pulling the reinforcing materials, known as roving and mats impregnated with thermosetting resins, through a draw bench. 
     The most widely used kinds of roving are glass yarns laid longitudinally to the shaped parts in order to increase their resistance to bending and pulling forces. 
     Mats are fibrous felts, laid out in an even manner, to improve interlaminar adhesion and make the mechanical characteristics of the material produced more homogeneous. 
     The polymeric matrix, consisting of thermosetting resins, may be chosen, according to the use required, from a wide range of resins, such as epoxy and phenolic or others. 
     The form of the parts produced through a suitable draw bench can obviously be very varied, of a solid or a tubular structure. 
     The pultruded part can be easily processed, bored and cut with ordinary tools, and can be joined and assembled by glueing, bolting or riveting. Polymerization takes place inside the draw bench by various processes, the most common being application of heat by electric resistances or by generation of radiofrequencies. 
     Purpose of the above invention is to produce pultruded shaped parts which not only possess the above characteristics but also those of generating diffused heat by transformation of electric current, with a greatly improved performance as will now be explained. 
     SUMMARY OF THE INVENTION 
     Subject of the invention is a process for producing shaped parts by pultrusion that transform electric current into diffused heat. 
     One or more nets, made from a continuous wire of highly conductive material coated with material of high insulating capacity, are inserted in a continuous manner in the plastic material, which nets are formed in the direction of feed of the shaped part conferring electric continuity upon it from beginning to end. 
     The shaped part is preferably tubular. 
     Tube section is preferably rectangular, low in height. 
     Nets are applied to one of the broad sides of the shaped part. 
     In one type of execution there are two nets side by side. 
     The two nets can be joined by an intermediate net of insulating material. 
     Nets are made of a weft wave material and are added to the known reinforcing materials such as continuous threads of fibreglass, or roving, and felted pieces of fibreglass, known as mats. 
     The matrix is of thermosetting resins of unsaturated polyesters, epoxy or phenolic resin. 
     The nets are put on before or after the resin bath needed for pultrusion. 
     Added longitudinally to the nets at fixed intervals, incorporated into the shaped part, are devices for electric sockets with a groove between them lengthwise to the shaped part. 
     By cutting the shaped part crosswise at the position of said devices, sockets are created for connection to a source of electricity. 
     In one type of execution these devices consist of a small flat plate of electrically conducting material associated to a second small plate also of electrically conducting material, with a central channel facing towards the first plate, the two being associated by rivets or the like. 
     The socket devices are inserted at the point where the shaped part will be cut through, thus obtaining oblong panels so that after said cut, each socket device is cut to make two such devices one being integrated into one panel and the other into the next panel. 
     The socket devices are placed on the central axis of symmetry of the shaped part or at its sides. 
     Advantageously there are two nets and the socket devices are placed in pairs, each net being connected to a socket placed at one end of the panel with a second socket placed at the other end. 
     Advantageously the panels are connected to electric current by two heads respectively insertible at the two ends of said panel. 
     One head has two contacts electrically connected internally at the two channels in the two sockets and these are at one end of the panel, while the second head has two contacts, also at the position of the channels in the two sockets, these other contacts being at the other end of the panel and connected by wires to fit a plug for an external electricity socket. 
     Foam material is put inside the panel to increase heat insulation so that the face of the panel opposite to that holding the electrically conducting nets remains substantially cold, both because of its distance from said net and because of the interposing insulation. 
     The nets are continuous in the shaped part but separated in the various preferred lengths, said lengths being connected by the socket devices. At the sides of the nets, laid in one or more units on one face of the tubular shaped part, there are lateral extensions. 
     The shaped parts, obtained as described, make possible formation of different objects and structural bodies of innumerable forms and characteristics. 
     For example, the oblong panels associated side by side, with heads at their ends, can be set up to form self-carrying walls for various uses, one side being cold and the other generating diffused warmth. 
     Another example is that of an oven for cooking purposes or treatment of various materials with heat emitting sides, formed of a number of panels such as those described or of a more powerful kind to create even higher temperatures if needed. 
     An indoor room can be easily warmed by one or more panels like the above, wall or ceiling mounted with the heat generating surface towards the environment. 
     The invention offers evident advantages. 
     In addition to their high mechanical characteristics, these pultruded parts provide the further advantage of generating diffused heat by means of electric current. 
     The rectangular tubular form with electric nets on one of the wider sides separated from the other by insulating material, ensures optimum generation of diffused heat from one side, the other being almost completely cold. 
     Realization of generators of diffused heat by a long electric lead is greatly facilitated by the net formed of highly conductive material with a coating of insulation, in loops along successive rows. 
     Electrical continiuity is in fact assured over the whole of the generator at whatever point the cut is made on the continuous body in which the net is inserted. 
     All this greatly facilitates installation in any place and in any structure as no problems of electrical or heat insulation can arise. 
     The shaped parts obtainable with this invention not only offer important advantages on structures and in environments generally but also enormously facilitate preparation of the structures themselves associating high structural solidity to generation of heat, for greatest user comfort. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Characteristics and purposes of the invention will be made still clearer by the following examples of its execution illustrated by diagrammatically drawn figures. 
     FIG. 1 Pultrusion installation for tubular shaped parts suitable for insertion of two parallel longitudinal metal nets of high electrical conductivity, and for insertion, at fixed intervals, of current devices, perspective. 
     FIG. 1 a  Detail view of FIG.  1 . 
     FIG. 2 Detail of a net, plan view. 
     FIG. 2 a  Detail view of FIG.  2 . 
     FIG. 3 Detail of a pultruded part, plan view. 
     FIG. 4 Oblong panel obtained by cutting the shaped part, plan view. 
     FIG. 5 The panel in FIG. 3, cross section. 
     FIG. 6 Oblong panel with heads for electrical connections, with two socket devices for the two nets, placed on the axis of symmetry, seen in perspective. 
     FIG. 7 As above with socket devices at the side, perspective view. 
     FIG. 8 Self-carrying wall generator of diffused heat, made by association of pultruded vertical oblong tubular panels, perspective. 
     FIGS. 8 a  and  8   b  Detail views of FIG.  8 . 
     FIG. 9 Oven created by pultruded vertical tubular parts, generators of heat, perspective. 
     FIG. 9 a  Detail view of FIG.  9 . 
     FIG. 10 Room in a house warmed by a set of horizontal pultruded tubular parts, generators of diffused heat, perspective. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The installation  10  comprises a frame  11  for the reinforcing material, a stand  21  to support the bath  22  for the matrix  50  of thermosetting resin, a frame  30  to feed in a pair of copper nets  72 ,  73  with insulating coating, a frame  40  for the draw bench  41 , for a pulling unit  42  and for the cutter  45 , and the support  47  for the roller surface  48  where the cut shaped parts emerge. 
     The frame  11  comprises a series of reels  56  resting on the surface  12 , for feeding in threads of fibreglass  60 , known as roving. 
     Through the rear transmission formed of pulleys  13  on the shaft  14  supported by the rear ends of the frame  15  and the front transmission formed of a roller  18  supported by the front brackets  17 , said roving connects with the fibreglass felt mat  65  fed in off the reel  64  that turns on the shaft  66  carried by the upper support  16 . 
     Association between roving  60  and mat  65  produces the reinforcing band  100  that, through the transmission rollers  23 ,  24  is compelled to pass into the fluid matrix of thermosetting resins  50  contained in the bath  22 . 
     On leaving said bath the band  100 , guided by the rollers, is transformed into a band  101  of plastic material incorporated into which is the reinforcing material of roving and mat. 
     Said band  101  enters the frame  30  that carries, on shaft  32  at its top, the reels  70  and  71  of coated copper net  72  and  73 ; these become inserted into the band  101  so producing a band  102 , complete with reinforcing material and nets, which then passes through the draw bench  41  pulled by the traction unit  42  with its upper and lower tracks  43  and  44 . 
     At the exit  51  from the draw bench, the band  102  is transformed into a tubular shaped piece  105  which, on leaving the traction unit  42 , is cut through by the cutter  45  turning on a pin  46 . 
     As will be seen in FIG. 2, the nets are formed of a continuous wire  74  of coated copper that forms a weft weave fabric whose successive rows, like  80  and  81 , are interlaced one with another. 
     The wire is continuous for the whole length of the net and, as may be seen in FIG. 2 for example, starts with  75  and ends with  76  without a break. 
     The enlarged illustration of some stitches shows that the wire  74  has a copper core  77  and insulating coating  78 . 
     It follows that wherever the pultruded shape is cut, thus also cutting through the nets, electrical continuity is assured for the the whole length of nets between two cuts. 
     The detail in FIG. 1 shows that, at certain intervals and before entry into the draw bench, a pair  110  of socket devices are inserted into the band  102 , each device comprising a small flat plate  113  and another small plate  144  with an axial channel  115  in it and sides  116 . 
     The two plates  113  and  114  are associated together by rivets  117 . 
     During association one end  118 ,  119  of the nets  72  and  73  is inserted between the two small plates  113 ,  114  of each socket device. 
     On the stand  47 , in FIG. 1, the oblong tubular panel  106  can be seen, said panel comprising two pairs of socket devices  127 ,  128  and  125 ,  126  obtained by cutting in half the socket devices  111  and  112  already indicated. 
     FIG. 3 illustrates an area of a pultruded shaped part  105  comprising fractions  85 ,  86  and  87 ,  88  of the nets  70  and  71 , connected to the pairs  110  of socket devices already described, by terminals such as  118 ,  119  and  120 ,  121 . 
     FIG. 4 illustrates the composition of panels  106  obtained by cutting across the shaped part  105  at substantially half the length of the pairs  110  of socket devices so that each forms two pairs of sockets  125 ,  126  and  127 ,  128 . 
     FIG. 5 shows the front of the panel  106  consisting of a narrow tubular shaped part with a rectangular cross section. 
     The positions of sockets  127  and  128  are clearly seen, and especially connection of the wire  118  in the fraction of net  85  to the socket  127  and of the wire  119  in the fraction of net  86  to the socket  128 , a connection made stable by rivets  117 . 
     Foam plastic material  145  for heat insulation is placed inside the panel. As seen in FIG. 5 the nets  72  and  73  can be extended to the corners  90  by extensions  91  and  92 . 
     It will be clear from this figure that one side  107  of the panel will be hot due to transformation of current circulating in the nets  85 ,  86 , while the side  108  will be completely cold both because of its distance from side  107  and because of the filling of insulating foam material  145  inside the panel. 
     FIG. 6 shows the panel  106  with nets  85  and  86 , complete with heads  130  and  135 . 
     Head  130  is formed of a bar  131  with a narrower extension  132  corresponding to the internal dimensions of the panel  106 . 
     At the centre of said head is a two-pin copper plug  133 , whose arms are sized to correspond with the dimensions of the grooves  115  in the current sockets  125  and  126  placed on the front of the panel. 
     The head  135 , of substantially the same structure as head  130 , presents contacts  136  and  137  these too able to penetrate inside the grooves  115  in sockets  127  and  128 , said contacts being connected by wires  140  and  141  to the electrical socket  142 . 
     FIG. 7 shows panel  146  with nets  85  and  86 , and with heads  150 ,  155 . Head  150  is formed of a bar  151  with a narrower extension  152  corresponding to the internal dimensions of the panel  147 . 
     At the two ends of said head are copper contacts  153  and  154  whose dimensions correspond to those of grooves  115  in the current sockets  125  and  126  placed at the sides of the panel and on its front. 
     The structure of head  155  is similar to that of head  150  having contacts  156  and  157 , these also able to penetrate inside the grooves  115  in the sockets  127  and  128 , said contacts being connected by wires  160 , 161  to the electric socket  162 . 
     FIG. 8 shows a self-carrying wall  170  formed of a series of poltruded tubular oblong panels  106  set vertically, placed side by side and joined at two heads, an upper head  171  and a lower one  172 . 
     Insertion of extensions  180  in the lower part of both heads inside said panels  106  associated side by side, helps to stabilize said association and ensure electrical continuity between the electrically conductive nets  85 ,  86 , generators of heat, that compose the panels and provide electric feed. 
     Head  171  presents electric bridges  173  and  174  formed of copper plugs, the dimensions of whose arms correspond to the holes  115  in sockets  125  and  126  incorporated into the panels  106 . 
     The lower head  172  substantially similar to the upper head  171  presents a pair of electric contacts  175  and  176  so placed and sized as to penetrate inside the holes  115  in the electric sockets  127  and  128  at the other end of the panel  106 . 
     By means of electric connections  177  and the wire  178 , an electric circuit can be closed between the various panels for regular feed from the main electricity supply through the plug  179 . 
     FIG. 9 shows an oven  190  for cooking or for heat treatment to various materials, formed of two side walls  191 ,  192 , similar to the wall  170  already described, a base  193  and a roof  194 . 
     The oven is closed by doors  195  on hinges  196 . 
     The walls  191 ,  192  are formed of panels  200  complete with heads  201  and  202  similar to those described for the wall  170  in FIG.  8 . 
     The panels are connected in parallel through conductors  203 ,  204  connected to the switch  205  served by a pilot light  206 . 
     FIG. 10 shows how the room  210  of a house can be warmed by a set  211  of three panels  212  substantially similar to panels  106  described above, associated by heads  221 ,  222  mounted on a wall  215 . 
     The panels are electrically connected to the conductor  223  and through the wire  224  to the plug  225  for connection to the socket  226  and to main electricity supply. 
     The applications described, such as the self-carrying wall  170  in FIG. 8, the oven  190  in FIG.  9  and the series of panels  211  in FIG. 10 show only a few examples of an infinite number of possible applications of the pultruded tubular bodies with a rectangular cross section, comprising the electric copper nets coated with insulating paint, generators of heat, like nets  85  and  86  already described.