Abstract:
In an automatic device for the insertion of small blocking strips or ribbons adapted for the insertion in the groups of mating holes of material consisting of laterally punched and coupled sheet groups, whereby each strip takes a U-shaped configuration and is fixed to the first and to the last sheet of the sheet group by means of adhesive areas provided in the strip itself, an improved structure of small strip inserting device, by which each small ribbon is cut from a continuous ribbon and inserted into position without special operation carried out on the receiving holes.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a device for the insertion of small blocking strips into multiple sheet material and, more specifically, for the insertion of removable small blocking strips into the perforations of laterally punched and coupled forms. 
     DESCRIPTION OF THE PRIOR ART 
     It is known that for a number of uses laterally punched forms are utilized which are coupled in a number of sheets, so that the side perforations are coincident. These coupled forms must be temporarily blocked to each other, so that as soon as necessary the forms may be detected from each other. 
     A widely used system is based on small ribbons or small paper strips, having adhesive areas provided on one of their surfaces, which are inserted in the mating holes of all the forms coupled to each other, and then folded in a &#34;U&#34; shaped, whereby said adhesive areas are engaged with the first and the last form in a position adjacent to the mating holes without interference with the intermediate forms. Consequently, by cutting the small strip at the mating holes, all the forms coupled to each other are caused to be instantaneously set free. 
     This system is based onto an automatic machine adapted to grasp the single small strip and insert it in the group of mating holes, it being thereafter U folded as above mentioned. 
     To date, however, that was only possible if the holes at which the small strip was applied were in advance enlarged or increased by their diameter with respect to the size normally used in the punched forms, as with a certain frequency the small ribbon or strip was otherwise not rightly inserted owing to the inserting device being easily offset with respect to the group of holes in which it had to be inserted. 
     Therefore, the subject machine had to be upstream provided with a hole enlarging device which was operated at predetermined intervals corresponding to the frequency at which the aforesaid small strips were inserted. 
     All this, as it is readily understandable, affects the small strip insertion rate and consequently the operating speed of the machine for the production of coupled forms. For an approximate evaluation of the negative incidence of the hole enlarging operation and small strip insertion on the whole rate of the entire form coupling cycle it will be enough to take into consideration that the coupling mechanisms may attain linear speeds of the continuous paper band, as formed by the forms joined along their opposite edges, up to 350 m/min. whereas the automatic machines for the application of small strips of the aforesaid type seldon may operate at linear speed of said paper band higher than 180 m/min. 
     PURPOSES OF THE INVENTION 
     The main purpose of the present invention is that of providing an automatic device for the insertion of small ribbons or strips onto forms, laterally punched and coupled in multiple groups, by which the aforesaid drawbacks are done away with, whereas the advantages of the system as above shortly described are maintained. 
     A more specific purpose of the present invention is that of providing a device of the aforesaid type in which the need of the hole enlargement operation at predetermined intervals is eliminated. 
     A further purpose of the present invention is that of providing a device of the aforesaid type which is of simple operation, of rugged structure and of easy maintenance, besides permitting the use thereof with whatever type of mechanism for the continous coupling of forms. 
     SUMMARY OF THE INVENTION 
     These purposes are achieved by means of a device for the insertion of small ribbons or strips, adapted to be inserted into groups of mating holes of sheet material, laterally punched and coupled in groups, whereby each small ribbon takes a U shape and is secured to the first and to the last sheets of the sheet group by means of adhesive areas as formed onto the small ribbon itself, the device being characterized by comprising feeding means for a continous ribbon adapted to be cut into the aforesaid small strips, means for the intermittent advancement of said ribbon along a predetermined path, cutting means adapted to engage said ribbon, according to a predetermined and adjustable frequency cross-wise with respect to the said intermittent advancement direction whereby said small strips are cut from said ribbon, supporting means, for said cutting means said supporting means being operated to carry out a first reciprocating motion in a direction perpendicular to said advancement direction of said ribbon, and to carry out a second reciprocating motion, in a plane perpendicular to the direction of said first reciprocating motion and means for the controlled displacement of a continuous strip of sheets coming from a sheet coupling device provided upstream of the device for the insertion of said temporarily blocking strips, said displacement means being engaged by said cutting means carrying therewith a just cut strip concomitantly with said second reciprocating motion of the said supporting means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The peculiar features and advantages of the present invention will more clearly appear from the following specification, with reference to the accompanying drawings wherein: 
     FIG. 1 is a general perspective view of the insertion device of the present invention; 
     FIGS. 2, 3 and 4 are side views of the device of FIG. 1; 
     FIG. 5 is a plant from the top of the device of FIG. 1; 
     FIG. 6 is a diagrammatic view of a group of coupled forms which are blocked by means of the device of the invention; and 
     FIG. 7 is a cross-section view in detail. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to the drawings, the device according to the invention includes a casing 10 at the top of which a plate 11 it is provided, an arm 12 being upwardly provided on said plate fitted to rotatably support a roll 14 of ribbon 15, from which the small strips or ribbons 16 (FIGS. 6 and 7) are to be cut for temporarily blocking the coupled forms. 
     Obviously the roll 14 is mounted and secured by means of a pair of conventional disks for supporting said roll which are idly mounted on a pin projecting from the arm 12. 
     The path of the ribbon 15 is clearly shown by dashed lines in FIG. 2 and it advances in the direction of arrows 17. 
     The ribbon 15 in its advancement passes around a first roller 18, a guide roller 19 and an intermittently-driving roller 20. 
     The roller 18 is journalled onto a pin or fulcrum 21 of a lever 22, one end of which carries a roller 23 engaged with the operating surface 24 of a disk cam which is rotated at a predetermined and adjustable rate by driving means not shown. 
     A lever-shaped pawl 27 is provided journalled at the other end of the lever 22, one end of the pawl being joined to a return spring 28, the other end of said spring 28 being anchored to a pin 29 which integrally projects from the lever 22. 
     The toothed end 30 of the pawl 27 engages a crown gear 31 rigidly secured to the advancement roller 20, thus forming an escapement mechanism. 
     Each time the projecting portion 32 of the cam 25 engages with the roller 23 during the rotating motion, the lever 22 rotates around the fulcrum 21 thus pulling back the pawl 27, the tooth 30 of which is kept in engagement with crown gear 31 by the action of the spring 28. 
     Accordingly a corresponding rotation of the crown gear 31, together with the roller 20, takes place thus driving a portion of the ribbon 15 to be advnced in the direction of the arrow 17. 
     Obviously as soon as the unrelieved portion of the cam 25 comes into contact with the roller 23, the several elements come back to their starting positions due to the return action as applied to the lever 22 by the return spring 33 which is anchored to the device casing. 
     At the exit side of the roller 20, the ribbon 15 enters a guide 34 provided with a slit 35 through which the ribbon is caused to pass and to protrude by a prefixed length with respect to the vertical plane defined by the outer surface of the guide 34. 
     For the cutting of the protruding portion of the strip 15, a blade 36 is provided having a blade carrier 37, the latter having a spacing plate 38 mounted thereto, the position of which is adjustable by means of a screw 39 with respect to the blade-carrier. 
     The plate 38 in turn is slidably mounted to the other surface of the guide 34, and serves to define the distance from the slit 35, at which the blade 36 engages the protruding portion of the ribbon 15 from the said slit. 
     One end of a return spring 40 is secured to the blade-carrier 37, its other end being secured to the casing 10 of the device. 
     One end of a second return spring 41 is fixed to the blade-carrier 37, the other end being fixed to the casing 10 for the reasons set forth hereinafter. The assembly consisting of the blade 36, the blade carrier 37 and the spacing plate 38 is actuated so as to carry out two concomitantly reciprocating motions namely: 
     (a) an horizontal reciprocating motion against the opposing action of the spring 40 until the blade 36 is brought to a suitable position for cutting the portion of the ribbon 15 protruding from the slit 35 at the predetermined distance from the spacing plate 38; 
     (b) a vertical reciprocating motion against the opposing action of the return spring 41, the blade 36 being thus caused to be lowered to carry out the cutting operation. Below the slit 35 a displacement roller 42 is provided against which the portion of the ribbon 15 cut by the blade 36 is transferred. 
     This roller 42 is journalled at the end of a lever 43 fulcrumed at 44 and undergoing the action of a return spring 45, one end of which is secured to the lever itself whereas the other end is anchored to the casing 10. 
     A follower roller 46 is further secured to the lever 43 for engagement with a cam 47 which is driven into rotation, so that the lever 43 is raised or lowered according to a predetermined cycle. 
     Similarly the cams 48 and 49 control the vertical reciprocating motion of the blade-carrier 37, while the cam 50 controls the horizontal reciprocating motion thereof, the rotation rate of the cams being obviously adjustable according to the desired frequency of the corresponding reciprocating motion. 
     By combining the two aforestated reciprocating motions a resulting rod-and-crank-type motion is obtained by which the cutting and inserting operations of the small strip or ribbon with respect to the upper sheet or form of the group, which at that moment passes onto the roller 42, take place while accompanying the motion of the sheet itself. 
     In other words, provided that the continuous band of forms passing between the roller 42 and the slit 35 does not stop or reduce the speed it has when the small strip insertion takes place, the relative motion between the form and the small strip, as brought into position by the blade 36, is null. 
     This is thus the reason why by the present invention the stated purpose is achieved, and the production rate of the device is thus increased to that one of the related form coupling group. 
     The small strip 16 is then applied by its portion, which has to be inserted through the group of holes and to be U-folded, to the last sheet of the group of sheets in a flag-like arrangement for the full diameter of the group of holes, so that downstream of the device of the present invention the above stated operation will be carried out by a suitable punch. 
     The present invention has been described with reference to a preferred embodiment, although modifications, changes and equivalent embodiments are possible and foreseable, all based on the use of means for cutting and inserting the small strip or ribbons having a motion such that the relative motion between the small strip and the hole to which the same small strip is to be applied is null at the moment at which the said insertion takes place, without appreciable change of the displacement speed of the band of coupling forms being processed. 
     These modifications and changes are obviously included withing the scope of present invention.