A device for the selection of large loose reams

Abstract: The selection device includes a sensor unit (5) which checks the flatness of the free surface of a sheet pack (P) at an edge (1a), and which moves vertically away from and into contact with the free surface of the pack (P); the sensor unit (5) extends along an axis (T) transversal to a direction of feed (A) and operates a blade (6) which defines the ream (1) and is opposite and attached to the said sensor unit, moving with the unit near to the edge (1a), and may be positioned parallel to the free surface of the pack (P); drive means (7) are envisaged for the blade (6), to move it from a position away from the edge (1a) until it makes contact with the ream (1), at which point the blade penetrates the pack (P), and a position in which it defines a gap between the ream (1) and the pack, in which the blade (6) is turned about the transversal axis (T) through an angle (α) sufficient to allow the transfer means (2) to penetrate the ream (1).

Description: The present invention relates to a device for the selection of large loose reams. In the case of large reams, that is to say, the reams used for sketches, drawings, printed copies, etc., a significant problem is ream selection in the machines designed to package them into separate packs. The sheets to be fed to the packaging machines, arriving from the cutting machine which produces them, are placed on a pallet in the form of a pack; the pallet is then positioned on a lift which gradually raises it automatically as an operator above selects and removes a pack of sheets destined to form a ream, so that the sheets are always piled to the same height. The use of an instrument similar to a gauge is normally envisaged for the selection of the ream from the pack of sheets, the fixed measuring arm being an element similar to a stop, and the movable arm being a blade which may be inserted between one sheet and the next. The operator determines the thickness of the ream to be obtained in accordance with the number of sheets of which it must consist and their thickness, then rests the gauge stop on the top sheet, allowing it to run over this sheet until the blade is inserted between two sheets, to separate the selected ream above from the remaining pack of sheets below. The edge of the selected ream is then raised and it is pushed towards the packaging machine downstream. In another, similar case, the machine which prepares the packs of sheets from which the reams are obtained counts the sheets and inserts a marker between one sheet and the next to define a ream in accordance with a preset number of sheets; the marker is a piece of paper or similar material, usually coloured, which protrudes from the pack of sheets. The operator must, therefore, lift and push the ream selected (again with the afore-mentioned gauge or, alternatively, automatic selection systems), positioned above the marker, in the direction of the packaging machine. Selection using automatic systems is extremely precise, although the markers are not always in the same position, due both to varying sheet dimensions and the different machines which prepare the packs. In particular, the manual selection of reams from a pack of sheets using a gauge is, given the production rates of current packaging machinery, the considerable size and weight of the reams, inconvenient and difficult for the operator. In order to overcome the disadvantages mentioned above, the Applicant has invented a semi-automatic selector (see patent US-5.244.340), with which the operator continues to use the gauge to select the reams, whilst the transfer of the ream to the packaging machine (being, as indicated, the most tiring stage) is completed by means of a servo-mechanism which uses a pair of horizontal blades, set parallel to one another and close to the edge of the pack of sheets. These blades are vertically adjustable and can penetrate the ream of sheets preselected by the operator. The blades are mounted on a carriage which slides along a horizontal guide, so that they slide parallel to the length of the pack of sheets, penetrating the preselected ream and feeding it to the packaging station. This solution without doubt facilitates part of the operator's work (he/she no longer pushes the selected ream to the packaging station manually), although the selected ream may be damaged, since selected sheets are not always raised to the required level when they encounter the blades in their operating zone. This problem arises due to selection with the gauge, inserted between the two blades, which creates only a small arc along the length of the sheets, due to the limited depth of the gauge itself and the operator's lifting strength; in this case, as the blades penetrate the ream it may still be compact with the rest of the stack of sheets, causing deformation of the sheets in that zone. A further disadvantage arises from the fact that the geometric configuration of the packs of sheets produced by the cutting machines is not always identical, especially with relation to the edges cut, where selection of the reams is effected, and may lead to the erroneous selection of the quantity of sheets which define a ream. The aim of the present invention is to eliminate the said disadvantages by creating a device for the selection of reams of sheets which is fitted to the afore-mentioned type of semi-automatic selectors which are automated, fast, easy to use and reliable for the division of upper reams. The technical features of the present invention, in accordance with the said aims, are clearly described in the claims herein and the advantages of the invention are more clearly shown in the detailed description below, with reference to the accompanying drawings which illustrate an embodiment by way of example only, and in which: figure 1 is a side view of the device for the selection of large loose reams fitted to a ream selection apparatus, with some parts cut away to better view others; figure 2 is a plan view of the selection device illustrated in figure 1, with some parts cut away and others shown in cross-section; figure 3 is a cross-section III - III as shown in figure 1; figures 4 and 5 show the selection device illustrated in the previous figures in two different operating configurations, that is to say, having made contact with the pack of sheets and, respectively, in the rotated position for selection of the ream, both being side views, scaled-up with respect to the previous figures; figure 6 is a side view with some parts cut away to better view others of the device shown in figures 4 and 5 in a further operating configuration, that is to say, with a lowered sheet pack compacting device; figure 7 is a perspective view of the device illustrated in the previous figures, in a position which refers to figure 1; figures 8 and 9 are side views with some parts cut away of the device disclosed as it rests on the pack of sheets, the outer edge of the device angled downwards and upwards respectively. In accordance with the accompanying drawings, and in particular with reference to figures 1, 2 and 7, the device disclosed allows the selection of large loose reams 1 from a stacked pack P of sheets resting on a surface (which is not illustrated) that moves along a vertical axis Z, located upstream of a packaging station C for the said preselected reams (the station is only partially shown, being of a known type). In figures 2 and 7 the numeral 2 indicates means for the transfer of the ream 1, preselected by selection means 3 (described in more detail later), in the direction of the packaging station C. These transfer means 2, of a known type and only partially illustrated, consist of a pair of horizontal blades 2c, mounted on a horizontal carriage 4 and designed to penetrate the sheets between the upper surface of the pack P and the base of the ream 1; the said blades 2c, positioned in correspondence with the edge la of the preselected ream 1 opposite that facing the packaging station C, are vertically adjustable (thanks to drive means connected to the carriage, which are not illustrated here) so as to obtain the transfer, by pushing, of the ream 1 in a direction of feed A, that is to say, towards the packaging station C. The afore-mentioned selection means 3 are located between the pair of blades 2c and consist, essentially, of a sensor unit 5 which checks the flatness of the free surface of the sheet pack P, another blade 6 connected to and opposite the sensor unit 5 and drive means 7 for both of the said elements. Following the sequence described above (and observing figures 1, 2, 3 and 7), the sensor unit 5 is aligned with the said edge of the ream 1 opposite that facing the packaging station C. It is mounted on a horizontal bar 4b, parallel to the horizontal carriage 4, and can move vertically away from and into contact with the free surface of the sheet pack P. More precisely, the sensor unit 5 extends along an axis T transversal to the said direction of feed A. The main element of the sensor unit 5 is a roller 8 which makes contact with the free surface of the sheet pack P, the roller turning freely about a support shaft 9, attached at both ends to corresponding roller-type cages 10 (bearings). Seats designed to house the shaft 9 may be added to the structure of these cages 10, the diameter of the slot being larger than that of the shaft 9, so as to allow the shaft to rock about an axis parallel to the direction of feed A depending on the flatness of the surface of the sheet pack P: this allows a further check of the surface of the sheet pack P, mainly effected along the width of the sheet pack P. The cages 10 are, in turn, fixed to a vertical plate 11, in turn attached to a relative vertical guide 12, the top of which is attached to the bar 4b; the guide 12 and plate 11 are moved vertically by a corresponding hydraulic piston 13, also housed in a frame attached to the bar 4b, which thus moves the roller 8 away from and into contact with the surface of the sheet pack P. The blade 6 which defines the ream 1 is opposite and attached to the sensor unit 5 (more clearly seen later), and moves with the sensor unit 5 close to the edge 1a of the sheet pack P so that it may be positioned parallel to the free surface of the said sheet pack P. More precisely, the blade 6 lies on a horizontal axis G (see fig. 2) which passes through the centre of the roller 8 support shaft 9 and consists of a flat blade with tapered free end, whilst the other end is attached to a first, vertical rod 14, in turn connected to a second, horizontal rod 15 which is attached to a support cradle 16 in such a way that it may slide along it. The support cradle moves with the shaft 9 so as to position the blade 6 correctly relative to the surface of the sheet pack P checked by the roller 8. The first, vertical rod 14 is moved by a first horizontal piston 17, also connected to the cradle 16, constituting part of the said drive means 7, and designed to allow the movement of the blade 6 along the length of the sheet pack P. The cradle 16 which supports the blade 6 consists of a vertical wall 16v to which the first rod 14 and first piston 17 are connected, and a horizontal surface 16r fixed to the wall 16v opposite the roller 8, having a wall 16n which is angled and set at a tangent to the roller: said wall acts as an extension of the roller 8 when the latter rests on the surface of the sheet pack P in order to determine the positioning of the blade 6. Moreover, means 6r are envisaged for adjustment of the distance between the blade 6 and the roller 8; these means 6r move the blade 6 vertically, parallel to the vertical axis Z, bringing it to a distance from the free surface of sheet pack P equivalent to the predefined thickness S of the ream 1. These adjustment means 6r (see figures 1 and 2) consist of the said first vertical rod 14, which supports the blade and is attached in such a way that it mat slide to a third vertical rod 18, fixed to the second horizontal rod 15. A slot 19 is envisaged in the first rod 14, for manual adjustment of the height of the blade 6 with respect to the roller 8, the first rod 14 also housing a handle 20 designed to lock the first rod once engaged in the third vertical rod 18, thus locking the blade 6 in position. The drive means 7 envisage not only the said first piston 17, which allows the blade 6 to make contact with and penetrate the ream 1, but also a second piston 21 positioned at the side of the roller 8 and attached, at one end, to the vertical plate 11. The other end of the second piston 21 has a first pin 28 parallel to the shaft 9 and transversally engaged in such a way that it may slide within a slot 29 in a first lever 30. One end of the lever is pivoted to the plate 11, whilst the other end is opposite a second pin 31, again parallel to the shaft 9, fixed to the cradle 16: in this way, when the second piston 21 is operated and raises the first lever 30 towards the plate 11, the end of the first lever 30 intercepts the second pin 31 which, in turn, causes the roller 8, the cradle 16 and so also the blade 6 which has penetrated the ream 1 to turn through an angle α (see figures 5 and 6). In this way a gap is defined between the ream 1 and the remaining sheet pack P, large enough to allow the said horizontal blades 2c to penetrate the ream 1. The plate 11 has an open section 11a at the roller 8 and cradle 16, in order to allow them to rotate correctly. Cradle 16 end stops are envisaged in order to obtain stable positioning of the cradle 16 as the sensor unit 5 is raised. These end stops are clearly visible in figures 3 and 7 and consist of a third horizontal pin 50, parallel to the second pin 31, and attached to the cradle 16. When the cradle 16 is moved away from the pack P below, this third pin 50 encounters a fixed horizontal wall 32, attached to the plate 11 and inserted between the first lever 30 and the vertical wall 16v of the cradle 16. This wall 32 also has a vertical screw 32v, with adjustable height which, during the downward rotation of the cradle 16, moves into the zone of contact with the third pin 50: in this way it is possible to adjust the position of the end stop for the cradle 16 downstroke by tightening or loosening the screw 32v. This position is, of course, always outside the maximum "range" of the curve of the edge of the sheet pack P and within the acceptable limits for the selection device. The sensor unit 5 also has means 24 for compacting the sheet pack P beneath the selected ream 1, when the ream edge 1a is in its rotated configuration; these means 24 essentially consist of a horizontal shoe 25 positioned beside the blade 6 and supported by a pair of pistons 26 and 27, in turn supported by the said horizontal bar 4b, one piston being horizontal and the other vertical, causing the blade to move in the direction of feed A and to move vertically. All of the sensor unit 5 and blade 6 movements previously described are regulated by means 23 which control the positions assumed by the said elements with respect to the sheet pack P and which operate adjustment and drive means 7 in such a way as to obtain an automatic cycle in the entire device. These control means 23 consist of both photocells of a well-known type, positioned opposite the sheet pack P to be selected (see figure 1), and sensors (not illustrated) connected to the various pistons in the device and used to detect the limit positions of the said pistons. The device thus configured selects reams 1 in the following way, starting from the machine start cycle configuration. Firstly, the blade 6 is set at a given distance from the roller 8 so as to determine the thickness S of the reams to be selected: the selection is effected by unlocking the handle 20 on the third vertical rod 18, so that the first blade 6 support rod 14 slides along the third rod (see arrow F in figure 1) to position the blade 6 at the exact height, being locked in place by relocking the handle 20. At this point, the sheet pack P is raised (see arrow F1 in figure 1) towards the carriage 4 until it covers photocell Fc1 which determines the pack P selection position. Piston 13 is then activated, allowing the entire sensor unit 5, together with the blade 6, to descend until the roller 8 comes into contact with the surface of the sheet pack P (see arrow F2 in figures 1 and 7); to ensure that the roller 8 comes to rest on the surface correctly, the piston 13 always arrives at its lower limit position. The roller 8 therefore adapts perfectly to the flatness of the surface of the pack P (in particular, to the pack transversal line), thanks to the shaft 9 ability to rock, also adapting the position of the cradle 16 and blade 6 to the geometric configuration of the sheet pack P; the horizontal surface 16r of the cradle 16 rests on the surface of the pack P, the former making contact with the roller via the angled wall 16n. With the blade 6 in a position perfectly parallel with the sheets of the pack P, the first piston 17 is activated, driving the blade 6 towards and into the pack (see arrow F3 in figure 4). When the blade 6 is in this position, the second piston 21 is activated, simultaneously turning the cradle 16 and blade 6, setting them at a fixed angle α to their starting point (see arrow F4 in figures 5 and 6); this lifting motion causes a gap to be created between the selected ream 1 and the remaining the sheet pack P below (again see figures 4 and 5) in order to facilitate the insertion of the pair of transfer blades 2c. To further facilitate the insertion of the pair of transfer blades 2c, the compacting shoe 25 is activated. Driven by the pair of pistons 26 and 27 in the directions indicated by arrows F5 and F6 in figure 6, the compacting shoe 25 is positioned at the remaining pack P, which is thus gently pressed down to allow insertion of the blades 2c. Before the latter push the ream 1 towards the packaging station C, both the shoe 25 and the blade 6 are respectively removed from the pack P and ream 1 and returned to their starting positions, so that the ream 1 may be safely transferred in the direction of feed A. Upon completion of ream 1 transferral, when the blades 2c have been drawn back and the sheet pack P raised, the device's operating cycle is repeated, following the sequence described above. The present device, therefore, achieves the aims described herein thanks to a simple structure with precision movements, and being, above all, safe to use; as is shown in figures 8 and 9, which illustrate a sheet pack with the edge facing, respectively, downwards and upwards. The possibility of checking the flatness of the surface of the sheet pack P, along the edge 1a to be turned, by using the roller 8, makes the penetration of the blade 6 safe, since the blade is positioned so that it "copies" the geometric configuration of the sheets of which the ream 1 will consist. The blade 6 is rotated in accordance with a fixed stroke of the second piston 21, irrespective of the position assumed by the blade (pointing down or up) and also allows increased safety in the insertion of the pair of transfer blades 2c: the rotation effected by such a device causes the entire edge of the ream for the entire width of the selected ream to be inverted, irrespective of the ream dimensions. This would not have been possible in selection using a conventional gauge. In this way, the pair of transfer blades 2c may penetrate the sheet pack P unhindered, irrespective of the distance between the said blades and the selection device. Moreover, given its extreme efficiency and notable precision in selection, this device may also be used to select reams from sheet packs containing ream reference markers: obviously, in this case there may be means for the suction of the ream reference markers, these means being positioned opposite the sheet pack so that they instantly remove the marker when the selected ream is transferred in the direction of the packaging station. The present invention, thus designed for the said objects, may be subject to numerous variations, as far as they are encompassed by the appended claims.

Claims: A device for the selection of large loose reams (1) from a stacked pack (P) of sheets resting on a surface that moves along a vertical axis (Z), located upstream of a packaging station (C) for the said preselected reams (1), the device being connected to means (2) for the transfer of the ream (1), preselected by relative selection means (3), in the direction of the packaging station (C); said transfer means (2) being mounted on a horizontal carriage (4) and positioned at an edge (1a) of the said preselected ream (1) opposite that facing the packaging station (C), being vertically adjustable and designed to penetrate the said sheet pack (P) between the upper surface of the pack and the base of the ream (1) so as to obtain the transfer, by pushing, of the ream (1) in a direction of feed (A) towards the packaging station (C), characterized by said selection means (3) including, near the transfer means (2), a sensor unit (5) which adapts to a transversal line of the free surface of the sheet pack (P) at least at the said edge (1a) opposite that facing the packaging station (C) and said sensor unit being vertically movable away from the free surface of the sheet pack (P) and into contact with the said surface; said sensor unit (5) extending along an axis (T) transversal to the direction of feed (A); a ream (1) definition blade (6) being attached to the sensor unit (5); drive means (7) being envisaged to drive the said blade (6) from a position which is practically horizontal and away from the said edge (1a) to at least: a position of contact with the ream (1), in which the blade (6) is shifted parallel with the free surface near said edge (1a) of the pack (P) and in a direction identical to the said direction of feed (A), so that it penetrates the sheet pack (P) and a position defining a gap between the ream (1) and the remaining sheet pack (P), in which the blade (6) is turned about the said transversal axis (T) away from the remaining sheet pack (P) through an angle (α) sufficient to allow the said transfer means (2) to penetrate the ream (1). The device as described in claim 1, characterized in that the said sensor unit (5) rocks freely about an axis which lies parallel to the said direction of feed (A). The device as described in claim 1, characterized in that the said sensor unit (5) includes a roller (8) which makes contact with the free surface of the sheet pack (P), positioned opposite the blade (6), turning freely about a support shaft (9), fixed at both ends in accordance with the corresponding transversal axis (T), in bearing cages (10) designed to allow the said shaft (9) to rock about the said axis which lies parallel to the direction of packaging (C) depending on said free surface of the sheet pack (P); the said cages (10) being fixed to a vertical plate (11) which is attached to a vertical guide (12) with adjustable height, attached to a carriage (4) so as to obtain the said positioning away from or in contact with the surface of the sheet pack (P). The device as described in claim 3, characterized in that the said blade (6) consists of a flat blade with tapered free end, whilst the other end is attached to a first, vertical rod (14), in turn connected to a second, horizontal rod (15) which is attached to a support cradle (16) in such a way that it may slide along it; the support cradle moving towards/with the support shaft (9) of the roller (8) so as to position the blade (6) correctly relative to the surface of the sheet pack (P); the first, vertical rod (14) being moved by a first horizontal piston (17), connected to the cradle (16) and constituting part of the said drive means (7), designed to allow the movement of the blade (6) along the length of the sheet pack (P). The device as described in claim 4, characterized in that the said cradle (16) consists of a vertical wall (16v) to which the first rod (14) and first piston (17) are connected, and a horizontal surface (16r) fixed to the wall (16v) opposite the roller (8), having a wall (16n) which is angled and set at a tangent to the roller so that it acts as an extension of the said roller (8). The device as described in claim 1, characterized in that the said blade (6) is fitted with adjustment means (6r) which move the blade (6) parallel to the vertical axis (Z) so as to define a distance from the free surface of sheet pack (P) equivalent to the predefined thickness (S) of the ream (1). The device as described in claim 6, characterized in that the said blade (6) adjustment means (6r) consist of the said first vertical rod (14), which supports the blade and is attached in such a way that it may slide to a third vertical rod (18), fixed to the second horizontal rod (15); a slot (19) being envisaged in the first rod (14), for manual adjustment of the height of the blade (6) with respect to the roller (8), the first rod constituting part of the said adjustment and drive means (7) and housing a handle (20) designed to lock the first rod once engaged in the third vertical rod (18), thus locking the blade (6) in position. The device as described in claim 3, characterized in that the said drive means (7) for the sensor unit (5) also have a second piston (21), being positioned at the side of the roller (8) and attached, at one end, to the vertical plate (11), the other end being attached to a first pin (28) parallel to the shaft (9) and transversally engaged in such a way that it may slide within a slot (29) in a first lever (30); one end of the lever being pivoted to the plate (11), the other end being opposite a second pin (31), parallel to the shaft (9) and fixed to a rotating support cradle (16) for the blade (6), so that when the second piston (21) is operated the roller (8), the cradle (16) and blade (6) turn through an angle (α) with respect to the sheet pack (P). The device as described in claim 8, characterized in that the said cradle (16) has end stop means which mark the top limit of the sensor unit (5) travel; said means consisting of a horizontal pin (50) which is parallel to the second pin (31) and directly attached to the cradle (16); the said third pin (50), in the vertical positioning of the cradle (16) encountering a fixed horizontal wall (32), attached to the plate (11) and inserted between the first lever (30) and the cradle (16); said wall (32) also having a vertical screw (32v), with adjustable height which, during the rotation of the cradle (16) towards the sheet pack (P), moves into the zone of contact with the third pin (50), being designed to adjust the position of the end stop for the cradle (16) movement towards the sheet pack (P) by tightening or loosening. The device as described in claim 1, characterized in that the said sensor unit (5) and blade (6) have means (23) which check the positions assumed by the said elements with respect to the sheet pack (P) and which operate the said adjustment and drive means (7). The device as described in claim 1, characterized in that the said sensor unit (5) has means (24) for compacting the sheet pack (P) which lies beneath the selected ream (1), during rotation of the latter; said means (24) consisting of a horizontal shoe (25) positioned beside the blade (6) and supported by a pair of pistons (26, 27), in turn supported by a horizontal bar (4b), one piston being horizontal and the other vertical, causing the shoe (25) to move in the direction of feed (A) and to move vertically. The device as described in claim 3, characterized in that the said blade (6) lies along a horizontal axis (G) which passes through the centre of the roller (8) support shaft (9).

Inventors: DALL OMO DAVIDE, PEDERZANI CLAUDIO, DALL'OMO, DAVIDE, PEDERZANI, CLAUDIO
Applicants: WRAPMATIC SPA, WRAPMATIC S.P.A.
Application year: 1995
Main classification: B65H3
IPC codes: B65H3, B65B35