FIELD OF THE INVENTION

The present invention concerns a covering machine using a protective film, to cover objects of a substantially regular shape, like a flat parallelepiped, such as for example books, exercise books, photo albums, boxes or other. In particular the covering machine according to the present invention can be used to cover books and allows to apply a covering film to the hard or flexible cover of a book, an exercise book, a magazine or other.

The machine according to the present invention has very reduced sizes, costs and consumption, and allows to reduce the execution time and to obtain high quality coverings which are stable over time

BACKGROUND OF THE INVENTION

A covering machine for books is known, described in the patent EP 0 908 328, which can be used in offices or in commercial activities such as bookshops, stationer's, bookbinder's etc., in order to cover books of various sizes with a protective film.

The known machine comprises a unit for cutting to size and heat-welding the covering films, and a work top on which the book to be covered is placed.

The machine comprises the feed unit to feed continuous strips from which the covering film is obtained. The films are thus supplied automatically from the feed unit which provides to position them on the work top, making them pass through the cutting and heat-welding unit located upstream of the work position where the book is positioned.

The known machine can also be used with sheets of covering film which have been pre-cut to a desired shape and size according to the size of the book to be covered. In this case the covering operation is carried out substantially in a manual manner; however a motorized drawing roller must be provided, which is activated in coordination with the action of the cutting and heat-welding unit so as to remove and discharge the scrap portion of the film after cutting and to carry out a heat-welding operation effective for every type of material used for the cover.

One disadvantage of the known covering machine is that in order to guarantee an adequate drawing action of the continuous strips or the scrap portions of the pre-cut sheets, it is necessary that the portions of the roller or of the feed unit in contact with the covering film are made of predetermined materials which guarantee a desired friction with most of the materials used for the film, which entails a considerable increase in production costs of the machine.

Moreover, the presence of at least a driving motor for the feed unit or for the drawing roller determines, in their turn, an increase in the costs of the machine, which also needs periodic or extraordinary maintenance in order to always guarantee optimal functioning.

Purpose of the present invention is to achieve a machine for covering books which is easy to use, has a reduced number of components, low production costs and which does not need long and costly maintenance operations.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claim, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In accordance with the above purpose, a covering machine according to the present invention is associated with a work top on which a covering film, for example a pre-cut sheet of desired conformation and size, and at least an object to be covered, such as, to give a non-restrictive example, a book, exercise book or magazine, in its turn disposed on the film, are disposed.

The covering machine comprises heat-welding means provided with at least a pair of clamping elements to clamp the film on the work top, and at least a heat- welding element. The heat-welding means have at least an inactive position, in which its clamping elements are reciprocally disposed separate so as to interpose between them at least part of the film on the work top, and an operating position in which the clamping elements are disposed close up, so as to clamp and heat- weld the film by means of the associated heat-welding element.

The covering machine according to the present invention also comprises cutting and removal means able to cut and distance a portion of scrap of the film after the heat-welding.

According to one feature of the present invention the cutting and removal means are mechanically coupled with the heat-welding means and have at least an independent movement with respect thereto, in order to assume at least an inactive position, in which they do not interfere with the film, and a removal position, corresponding to the operating position of the heat-welding means, in which they thrust the scrap portion so as to distance it from the remaining part of the film which remains on the work top.

According to one solution of the present invention, at least a first clamping element of the clamping elements moves with respect to a second of the clamping elements in a direction substantially perpendicular to the work top.

According to this solution, the cutting and removal means comprise a bar which extends for the whole width of the clamping elements and is movable in a parallel manner to the first clamping element.

In this solution, advantageously, also the bar which has the function of cutting and removing the scrap moves, from the inactive position to the operating position, in a direction substantially perpendicular to the work top.

According to a variant, the cutting and removal means comprise two or more bars, hinged or in some way connected to each other so as to make a simultaneous and coordinated movement when they are driven.

In this way, the direct association of the cutting and removal means, having one or more bars, with the heat-welding means, allows to avoid the use of costly motorized removal rollers, substantially reducing the sizes and the costs of production and functioning of the machine. Moreover, as there are no motorized movement elements, the times and costs of maintenance are considerably reduced. This also allows to achieve a covering machine which is extremely compact and much lighter in weight.

Moreover, from the moment that the scrap portion of the film is removed by means of a mechanical thrust action exerted on its surface by the cutting and removal means, there are no possible problems of ineffective friction between some types of material which make up the film and the removal rollers of the state of the art.

According to a variant of the present invention, the covering machine comprises first lever means, mechanically coupled with the heat-welding means, and which can be driven manually to determine their movement. The covering machine also comprises second lever means mechanically coupled with the cutting and removal means, which can be manually driven in order to move the cutting and removal means disposed substantially contiguous to the first lever means.

This facilitates the use of the machine by a single operator who can drive both levers with the same hand, allowing a considerable reduction in the covering times.

According to a variant of the present invention, the covering machine comprises resting means for a part of the film corresponding to the scrap portion after heat-welding and disposed substantially coplanar to the work top and at a predetermined distance from it, in order to determine a passage seating for the cutting and removal means. The resting means are able to cooperate with the heat- welding means, disposed in the operating position, so as to constrain, at least partly, the part of the film during the heat-welding.

According to another variant of the invention, the resting means are conformed so as to define at least a sliding surface suitable to facilitate the removal of the waste portion of film after heat- welding and cutting.

According to a further variant the machine comprises support means, associated with the heat-welding means, configured to define an abutment surface, substantially perpendicular to the work top, on which at least a lateral portion of the object to be covered is rested.

According to a further variant, the support means can be moved between at least a closed or folded position, and an open position in which they are substantially aligned with the heat-welding means, extending perpendicularly to the work top.

In this way, by disposing the second resting means in the open position, it is possible to position, with extreme precision, the object to be covered, even very thick objects, so as to make the cut and relative heat- welding precise and aligned.

The present invention also concerns a covering method comprising a first step in which a covering film, for example pre-cut to a desired conformation and size, in contact with the work top, is disposed on the work top, and at least an object to be covered, such as, to give a non-restrictive example, a book or exercise book or magazine, is in turn disposed on the film.

The method comprises a clamping step to clamp the film in which, by means of heat- welding means provided with clamping elements, the film is clamped on the work top. In the clamping step, the clamping elements are moved in a substantially manual manner from an inactive position, in which they are disposed reciprocally separated so that the film is interposed between them, to an operating position in which the clamping elements are disposed close up, so as to clamp the film onto the work top.

The method then comprises a welding step in which by means of a heat- welding element associated with at least one of the clamping elements, the film is heat-welded to size according to a predetermined line of heat-welding coordinated with the shape of the object to be covered.

The method also comprises a cutting and removal step, in which by means of cutting and removal means a scrap portion of the film is removed following the heat-welding.

According to one feature of the present invention, in the cutting and removal step the cutting and removal means are moved, at least independently of the heat- welding means, between at least an inactive position, in which they do not interfere with the film, and a removal position, corresponding to the operating position of the heat-welding means, in which the scrap portion is thrust by the cutting and removal means and distanced from the film which remains on the work top. In this way the removal of the scrap portion of the film occurs in correspondence with a heat-welding line determined by the action of the heat- welding means.

According to a variant of the present invention the heat-welding means are driven manually by means of first lever means and the removal means are driven manually by means of second lever means, in which the first lever means and the second lever means are disposed contiguous.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein: - fig. 1 is a plane view of the covering machine according to the present invention;

- fig. 2 is a lateral view of a detail of the machine in fig. 1 ;

- figs. 3 and 4 are lateral views of the machine in fig. 1 in different work configurations;

- fig. 3 A is an enlarged view of a detail in fig. 3;

- fig. 4A is an enlarged view of a detail in fig. 4;

- figs. 5 and 6 are schematic front views of portions of the machine in fig. 1 in two different work configurations;

- figs. 7 and 8 are lateral views of the machine in fig. 1 in two different work configurations;

- figs. 9 and 10 are front views of a variant embodiment of the machine in fig. 1 two different work conditions.

DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF EMBODIMENT

With reference to the attached drawings, a covering machine 10 according to the present invention can be used to apply a protective film or sheet 14 onto an object, in this case, shown as a non-restrictive example, a book 16 with a hard or flexible cover.

The machine 10 comprises a work top 12, two resting shoulders 17 associated with a box-like body 18 and disposed at opposite lateral ends in correspondence with a rear edge of the work top 12, heat- welding means 20 stably associated with the work top 12 by means of the box-like body 18 and the shoulders 17, and a cutting and removal bar 32 to remove the scrap portions 15 of the sheet 14, which is mechanically coupled with the cutting and heat-welding unit 20, as will be described hereafter.

The work top 12 has a rectangular shape such as to define an upper resting surface 12a for the sheet 14, such as a pre-cut film of a desired conformation and size coordinated to the size of the book 16.

The sheet 14 is spread on the surface 12a with its peripheral edges substantially parallel to the edges of the top 12. In particular, the sheet is disposed folded along predetermined folding lines 14a, parallel to at least two of its opposite peripheral edges so as to define two opposite lips 14b into which the covers of the book 16 will be inserted.

The heat-welding means 20 have a longitudinal development substantially equal to the width "L" of the top 12 and comprise a pair of clamping elements, respectively upper 22 and lower 24, in order to clamp the sheet 14 during its heat-welding. The heat-welding means 20 also comprise an electric resistance 28, of the known type, for example a wire resistance, stably attached to one of the clamping elements 22, 24, which extends in a rectilinear manner along the entire longitudinal development of the heat-welding means 20. In this case, the lower clamping element 24 acts as support for the electric resistance 28, which is activated in a known way by means of a micro switch or other type of switch.

The first clamping element 22 or upper element (figs. 2, 3A and 4A) is mechanically connected to the box-like body 18 and to the shoulders 17. The first clamping element 22 is an upside down "U" shape having two rectilinear and parallel lateral portions 22a, 22b, the terminal ends 22c of which (fig. 4A) are used to clamp the sheet 14 and for the heat- welding operation. The two portions 22a, 22b are separate so as to define a housing seating 23 for the cutting and removal bar 32.

The first clamping element 22 is mobile with respect to the box-like body 18 and to the shoulders 17 in a direction perpendicular to the surface 12a, between a first inactive position, in which it is disposed raised with respect to the surface 12a, and an operating position in which it is disposed overlapping, that is, in contact with the second clamping element 24, that is, with the electric resistance 28.

In particular, a first portion 22a of the first element 22, close to the top 12, cooperates with the second clamping element 24, bringing its end 22c into abutment with the electric resistance 28 disposed on the second clamping element 24, clamping the sheet 14 and determining the heat- welding thereof. The second clamping element 24, or lower element, is in fact stably attached in correspondence with a rear edge 12b of the work top 12, so as to dispose the electric resistance 28 substantially coplanar to the surface 12a.

The second portion 22b of the first clamping element 22 cooperates with a rest element 36, which is oblong and stably attached for example at the shoulders 17 to the work top 12, coplanar to the work top 12 and at a predetermined distance from it, so as to determine a passage seating for the cutting and removal bar 32, interposed between the portions 22a and 22b of the upper clamping element 22. When the first upper clamping element 22 is in the operating position, the corresponding lower end 22c is in fact disposed in contact through abutment with the rest element 36, clamping a portion of the sheet 14 which will comprise the scrap part 15 to be eliminated after the heat-welding.

The rest element 36 is shaped with a transverse profile, for example triangular or curvilinear, so as to define an efficient contact surface through friction during the clamping of the sheet, and to make a sliding surface which facilitates the removal and discharge of the scrap 15 after the cutting;

The first clamping element 22 can be moved manually between the inactive position and the operating position by means of a first lever 40 pivoted to one of the shoulders 17. In figs. 2-4 the first lever 40 is shown schematically, indicating only a relative end corresponding substantially to a gripping end.

The cutting and removal bar 32, for example of a regular parallelepiped shape and mating with the seating 23, develops substantially for all the length "L" of the first clamping element 22. The cutting and removal bar 32 is solid with the clamping element 22 and is normally disposed in a rest position in which it is at least partly contained inside the seating 23, not protruding, or protruding only slightly, from the lower end 22c of the first clamping element 22 (fig. 3 A). In this way, when the first clamping element 22 is in its inactive position the bar 32 does not interfere with the sheet 14.

The removal bar 32 is also translatable, independently from the first clamping element 22, from the rest position to a removal position in which it protrudes from below the seating 23. In the removal position (fig. 4A), when the first clamping element 22 is in its operating position, the removal bar 32 thrusts the scrap portion 15 of the sheet 14, that is the portion of the sheet 14 to be thrown away, which is removed by mechanical separation along the line of heat- welding performed by the resistance 28, distancing it therefrom.

The cutting and removal bar 32 can be moved manually by means of a second lever 44, also pivoted to the shoulders 17 and disposed substantially contiguous to the first lever 40. The lever 44 acts for example by abutment on a portion of the bar 32, by means of a rod 45. In figs 2-4 the second lever 44 is shown schematically, indicating only a relative end corresponding substantially to a gripping end.

The cutting and removal bar 32 is also coupled with two or more thrust springs 34 (figs. 3 A, 4A, 5 and 6), disposed inside the seating 23. When the relative lever 44 is released, the springs 34 thrust the bar 32 into its active position, executing the cutting and removal of the scrap 15. On the other hand, the springs 34 are kept in a compressed condition by keeping the second lever 44 manually raised.

In the variant shown in figs. 9 and 10, the cutting and removal bar consists of two bars, indicated 32a and 32b respectively, connected to each other in correspondence with their centers by means of a pin 33, in order to obtain a substantially scissor-like movement.

The two bars 32a and 32b are driven by means of a rod 45 connected to the second lever 44 (not shown in figs 9 and 10), against the action of a return spring 34, from a non-operating raised position (fig. 9) to a lowered position in order to discharge the scrap 15 (fig. 10).

The presence of two bars 32a and 32b prevents possible problems of the single bar 32 jamming, and amplifies the lowering movement in correspondence with the median strip of the work top 12, where there is certainly present the scrap 15 to be eliminated, irrespective of the size of the object to be covered.

The machine 10 also comprises (figs. 7 and 8) a substantially planar support 47 coupled with the shoulders 17 and with the box-like body 18; the support 47 extends for the whole width of the box-like body 18 and is disposed with respect to it in such a manner so as to define an abutment surface 48 perpendicular to the work top on which the lateral edge of the book 16 is rested.

The support 47 is pivoted on an upper peg 49 and can be moved between a closed or folded position and an open position in which it is aligned to the first clamping element 22 extending perpendicularly to the work top 12. The support 47 has a development such as to allow the positioning by abutment of the edge of a book 16, even a very thick book, therefore facilitating the covering operations, and it is thus possible to contain the bulk in height of the machine 10.

The machine 10 as described heretofore functions as follows.

In a first step, first the sheet 14 and then the book 16 to be covered are disposed on the work top 12 (fig. 2). The sheet 14 is folded along predetermined folding lines 14a so as to define the lips 14b. An edge of the sheet 14 is disposed between the first 22 and the second 24 clamping element and the rest element 36.

In a subsequent step the sheet 14 is clamped between the clamping elements 22, 24 and the rest element 36, by driving the first lever 40 which determines the movement of the first clamping element 22 from its inactive position to its operating position (figs. 3 and 3A).

In this position the electric resistance 28 is disposed substantially in abutment with the end 22c of the first portion 22a of the first clamping element 22. A portion of sheet 14 corresponding to the scrap 15, is clamped between the rest element 36 and the end 22c of the second portion 22b of the first clamping element 22.

In a subsequent heat- welding step the electric resistance 28 is driven, for example by means of a micro-switch controlled automatically by the lever 40, which determines the heat-welding to size of the sheet 14 along a predetermined heat- welding line, corresponding to the subsequent cut; the heat- welding line is rectilinear, and in correspondence with it, a first edge of the book 16 is also sealed. This operation, which is already known, is not described further here.

Finally, in a cutting and removal step (figs. 4, 4A), the removal bar 32 or the bars 32a, 32b are driven, manually releasing the second lever 44. This release action determines the extension of the springs 34 which, in their turn, produce the movement of the removal bar 32 from its rest position to the cutting and removal position. The portion of scrap 15, separated from the sheet 14, is therefore thrust by the bar 32 and distanced, for example toward a container for rubbish.

The manual drive of the second lever 44 causes the bar 32 to return into the rest position, which compresses the spring 34, and the first clamping element 22, by means of the joint movement of the first lever 40 and of the second lever 44, is repositioned in its inactive position to be used in subsequent heat-welding and cutting operations.

Subsequently the book 16 and the sheet 14 are moved, for example rotated, in order to carry out the cutting and the heat-welding of a second edge of the book, in the known way, repeating the steps previously described for cutting and removing the scraps 15 of the sheet 14.

It is clear that modifications and/or additions of parts may be made to the covering machine 10 as described heretofore, without departing from the field and scope of the present invention.