Abstract:
A machine for covering articles with sheets of plastic material. The machine includes a device suitable for cutting and sealing the sheets that cooperate with a work plane and a guide suitable for arranging a roll of a continuous sheet of plastic material in a suitable position for unrolling subsequent portions of the continuous sheet and the positioning thereof on the work plane.

Description:
This is a national stage of PCT/EP06/064045 filed Jul. 10, 2006 and published in English. 
     FIELD OF THE INVENTION 
     The present invention relates to a machine for covering various types of articles. 
     BACKGROUND OF THE INVENTION 
     In the prior art machines are known for covering books with sheets of plastic material. 
     One of said machines is disclosed in patent application WO 03/004282. The machine comprises a sheet sealing and cutting assembly that cooperates with a work surface. The assembly comprises a first and a second element of which at least the first element is movable with respect to the other and the two elements are arranged on opposite sides of the work surface. The first element comprises a sealing and cutting blade having an electric current that passes through it and the second element comprises a sealing and cutting counterblade. Driving means is provided for moving the sealing and cutting blade from a rest position to an operating position in which the sealing and cutting blade engages with the sealing and cutting counterblade. The first element and the driving means belong to a unit connected to the work surface in a removable manner. The unit furthermore comprises elastic retaining means for retaining said blade in the rest position. 
     The plastic sheets that are used for covering the cover of a book are only single sheets of plastic as the machine does not accept a continuous single sheet of plastic material. 
     In this way, the operation of covering the numerous articles becomes tiresome for the user, who has to load a single sheet of plastic material for each operation. 
     Furthermore, the operation becomes costly, as the remaining part of the individual sheet of plastic material is no longer usable for covering another articles. 
     SUMMARY OF THE INVENTION 
     In view of the prior art, the object of the present invention is to provide a portable machine for covering various types of articles that overcomes the aforementioned drawbacks. 
     According to the present invention, this object is achieved by means of a machine for covering articles with sheets of plastic material, said machine comprising positioning means suitable for cutting and sealing the sheets that cooperate with a work plane, characterised in that it comprises means suitable for arranging a roll of a continuous sheet of plastic material in a position that is suitable for unrolling successive portions of said continuous sheet and placing them on said work plane. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features of the present invention will become clearer from the following description of embodiments thereof illustrated by way of non-limitative example in the attached drawings, in which: 
         FIGS. 1-5  show the portable machine for covering various types of articles in various operating steps according to a first embodiment of the present invention; 
         FIG. 6  is an exploded view of a part of the machine in  FIG. 1 ; 
         FIG. 7  is a portable machine according to a second embodiment of the invention; 
         FIG. 8  is a portable machine according to a third embodiment of the invention; 
         FIG. 9  is a schematic section view of the machine in  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1-5  there is shown a machine for covering articles according to the first embodiment of the present invention. This machine uses a roll  1  of a continuous sheet of flexible plastic material of which successive portions of sheet suitable for covering articles of different type and in particular the covers of the books can be taken, and comprises a work plane or surface  2 . The roll  1  is arranged adjacent the rear part  15  of the work plane  2 . 
     The machine comprises means  30  for positioning the roll of the continuous sheet of plastic material; said positioning means  30  are integral with the work surface  2 . 
     The work plane  2  comprises, on opposite side ends, protrusions  3  suitable for guiding the sheet of plastic material that is unwindable from the roll  1  ( FIG. 1 ). The roll  1  does not have a structural core in cardboard or another material; the plastic material of the roll  1  has side flaps  4  between which the cover of an article, for example a book, is deposited, that have to face upwards. Preferably, as shown in  FIGS. 1-5 , the positioning means  30  are extensions of the protrusions  3 . 
     The removed border of the sheet of plastic material must emerge from the work plane  2  at a distance that is such as to enable the book  6  ( FIG. 2 ) to be positioned. The sheet of plastic material has to be arranged in slits  5  formed between the protrusions  3  and the work plane  2 . 
     Preferably, the work plane  2  has an additional work plane  7 , preferably hinged at  8  on the work plane  2 , where the book  6  with the cover arranged inside a flap  4  of the sheet of plastic material is positioned. 
     In the front end  9  of the work plane  2 , in the zone adjacent the end of the protrusions  3 , there is a hot sealing and cutting blade  10  that is visible in  FIG. 6 . The blade  10  is arranged on a brass seat  11  fixed to the work plane  2  by means of screws  12 ; a layer of Teflon  13  is arranged between the blade  10  and the brass seat  11  and the blade  10  itself is covered by a further layer of Teflon  14 . Electric current generated by an appropriate power supply unit that is not visible in the figures is passed through the blade  10 . 
     On pins  20  arranged adjacent the ends of the blade  10  a welding and cutting counterblade  21  is suitable for engaging. The pins  20  also act as guides for the counterblade  21 . 
     For cutting the sheet of plastic material, the roll  1  is rewound until it reaches the cutting zone of the sheet of plastic material. Subsequently, the counterblade  21  engages with the blade  10  in an operating or cutting position; lastly, the cut is performed by arranging the counterblade  21  on the coupling and guide pins  20  and exerting even pressure on the counterblade  21  ( FIG. 3 ) towards the blade  10 . 
     Subsequently, the roll  1  is rewound, but not completely, so as not to make the sheet of plastic material emerge from the slits  5  of the guides  3  ( FIG. 4 ). In this way the work plane  2  is kept free for subsequent cuts of the sheet of plastic ( FIG. 5 ). 
       FIGS. 7 and 9  show a second embodiment of the machine for covering various types of article according to the invention. The only difference between said machine with respect to the features of the machine in  FIGS. 1-6  consists in that said positioning means comprise a gap  50  suitable for receiving the roll  1  of plastic material. Said gap is integral with the work plane  2 . 
     In  FIG. 8  there is shown a third embodiment of the machine for covering various types of articles according to the invention. The machine in  FIG. 8  differs from the machine in  FIG. 7  because the additional plane  7  is not hinged on the plane  9  but is detached therefrom to act as a closing element of the machine.