EP1136404A2 - Device for longitudinally aligning plate-like elements in a feeding station of a machine for treating them - Google Patents

Abstract

Device (1) for the longitudinal alignment of plate elements (2) within an infeed station of a machine working them. The aforementioned device is secured by two lateral brackets (9, 10) between which is settled a conveyor track for the said plate elements, comprising two plates (5, 6) folded downwise according to a line (7) non-perpendicular in the meaning of the shifting (3) of the said plate elements (2). The latter are moved downstream by means of at least two conveyor belts running around at least two pulleys (15, 16) secured between unmovable bearings (11-14) at the input of the said device. The device (1) has on its leading edge a protection plate (39) over which are flaps (30-32) movable and interdependent of a transverse shaft (24) connecting the leading edges of the two lateral brackets (9, 10). This shaft is moved by an alternate rotation between 0 and 45 degrees, synchronized with the production speed of the machine in order to allow the successive alignment of the said plate elements (2). It has as a characteristic to be linked and made of several segments (26-28) each one of them bearing one of the said flaps (30-32).

Description

The present invention relates to a device for alignment longitudinal of plate elements in a feed station machine working them for packaging production. In such machine, the elements in plate, or sheets of paper or cardboard, are successively taken from the top of a pile and brought flat towards a linking work stations such as printing stations, cutting and ejection of waste, before being re-stacked in a reception.

At the introduction, the sheets are stored on a battery tray provided with automatic vertical movement with chains, so that the upper level of the stack remains constant during the introduction of the sheets into the production machine. The leaves are taken, one by one from the top of the stack, by lifting suction cups which will carry them towards suction cups conveyors. With a horizontal back-and-forth movement, the suction cups bring each sheet towards a table margin where the plate elements are thus deposited in a sheet.

One way to transport each sheet from the entrance from the margin table to the first processing station is to use jointly a training mat, consisting of belts, and pebbles pressers that keep the sheet on the carpet and bring it to the in front of the first work station. Each sheet is then taken away in the stations which follow by a clamp bar mounted on a train of chains.

It's in the introductory station, just before the margin table, that the object of the present invention finds its use. To ensure good operation of the machine, it is necessary, on the one hand, to guarantee the correct alignment of the front edge of each plate element introduced from so that it is not biased, and secondly to ensure the rate at which these elements are deposited on the margin table. This last condition defines the longitudinal location of the sheet on the carpet, either its positioning in the direction of its movement, so that the gripper bar can correctly grasp it when it is passage. This cadence can be physically measured by the spacing existing between two front edges of two successive plate elements on the margin table. Installation of a device for edge alignment front of the sheet makes it possible to fulfill both of these two conditions in the measure that this device works in synchronism with the production speed of the machine.

A device which allows the longitudinal alignment of the sheets is usually formed of a transverse shaft connecting, from one end to the other, the width from the margin table. This tree is placed slightly below the level top of the sheet held by the suction cups. When she is oriented vertically, a blade, extending along the transverse shaft and integral with it, acts as a stop for the front edge of the sheet and thus allows its alignment. Synchronized with the production rate of the machine, the shaft is driven by a repetitive movement in rotation from 0 to 45 degrees, so that the blade constitutes a shutter placed alternately in a closed vertical position, and in an open oblique position which allows in the latter case the passage of the sheet in the margin table.

Several devices of this kind are known to date but few of them take into account a subordinate problem linked to the initial state of sheets to be fed into the production machine. By nature organic, sheets of paper or cardboard used in clothing packaging are particularly sensitive to ambient conditions in which they are processed or stored. The humidity level of the air surrounding is one of the main parameters that influences significant mechanical, dimensional and above all leaf geometric. Although initially planar, the latter will often tend to bend due to variations in humidity surrounding air for example, but also following a deposited impression on one of its faces. This bending phenomenon is usually designated by the term "tuilage" in the jargon of the trade. The curl is particularly noticeable for sheets of corrugated cardboard and, is all the more marked that the thickness of the sheet is great or that the quality of the materials constituting the two sides of the sheet differs; which is often the case for aesthetic packaging boxes with prints. It should also be noted that the phenomenon of curling is not necessarily generalized by a deformation symmetrical about one of the two axes of symmetry of the sheet. It may be in fact that the sheet is affected by a more pronounced curvature in its left half than in its right half or vice versa.

Machine use of heavily tiled sheets poses different problems especially when introducing the sheet into the table margin, but also when aligning the front edge of the sheet just before its introduction. Being generally gripped by suction cups in its central part, the engagement of a heavily tiled sheet in the table margin causes discomfort at the lateral parts of the leaf which will tend to hook against the front edge of the margin table. Indeed, seen the concave curvature of the leaf, the edge of the lateral parts of these leaves is well below the introductory level which corresponds to the part leaf center, held by suction cups.

To remedy this problem, it is known to use tablets placed on the front of the margin table as they were provided for in patent CH 651,807. Consisting of plates or bars curved downwards, these shelves facilitate the insertion of the side parts annoyingly curved with a leaf affected by a certain curl.

However in the case of strongly tiled leaves must be used, the use of a shutter like the one described above constitutes always an obstacle for their passage. Indeed, the side parts drooping of these leaves will still butter up against the parts side of the open shutter, while risking to corner the corners of the sheet. For to overcome this problem, one of the known solutions consists in reducing the length of the shutter, keeping only its central part so that the side edges of the tiled sheet can then pass without hindrance following the clearance lateral thus formed. This solution requires partitioning the shutter into several removable elements or in a multitude of displaceable segments at will.

However, the practice of this option reveals several disadvantages which are on the one hand a reduced alignment, undesirable, limiting to the central part of the leaf which is a function of the importance of its curling, and on the other hand additional handling to be practiced in a small and difficult space, requiring the use of auxiliary tools assembly and disassembly of the shutter. Knowing that the curling of stacked leaves on the battery holder in the insertion station also varies depending on the stack height, such an option will require during production, a share a permanent control of the passage of the sheets over the open shutter, and on the other hand a series of repeated manual interventions aimed at adapting the length of this component according to the importance of the curvature of the leaves. These multiple interventions consequently imply frequent stops of the machine which increases the cost of production.

The shape of the side shelves, favoring the introduction of the leaf, varies mainly according to the maximum clearance that can offer, in its lateral parts, the device for the longitudinal alignment of the leaf. This clearance is inversely proportional to the space occupied by the side parts of the flap when it is adapted to the configuration necessary to allow the passage of sheets of a certain curl. The greater the clearance at the ends of the flap, the better the passage of the leaves and all the stronger can be their curling. But of a contradictorily, the greater the contact length of the front edge the sheet against the shutter, the better the alignment of the sheet and all the more the smaller the lateral clearance.

Until now, the machine operator has been forced to find the compromise that best suited the particular situation of these two conflicting observations, which resulted in repeated adjustments and little dressers such as those mentioned above.

To remedy these drawbacks, the object of the present invention proposes, for the longitudinal alignment of sheets, a universal joint device whose the shaft of the articulated stop flap can acquire a shape which adapts to the curvature of the front edge of the tiled sheet. To this end, the device of this invention conforms to claim 1.

The advantages resulting from the present invention are mainly recorded in the fact that such a device allows on the one hand align the sheet on almost all of its front edge to a range of leaves affected by significant curling (up to 4 to 5%), symmetrical or asymmetrical. On the other hand, the device according to the invention to the advantage of being able to remain permanently in the introduction station thanks to its particular ability allowing it to easily modify its geometry to adapt to the curved shapes of the tiled leaves. Advantageously, none part must not be added or removed from the flap of said device, and no tools auxiliary is only necessary for its adjustment, which saves time sensitive during the preparation of the machine in the case of a new job. Finally by lack of existence, the risk of losing certain parts of the shutter has the advantage of being totally excluded in this new concept.

In order to define some terms describing the position and the orientation of certain elements within the machine referring to the present invention, we will mention the names "driver side" and "opposite side driver "used without question to refer to a designated side relative to the longitudinal median axis of the machine. This choice avoids any confusion arising with conventional names left and right dependent on the observer's point of view. In a perspective similar, we will use the usual terms "longitudinal" and "transverse" which always refer to the median axis of the machine whose orientation is determined by the direction of travel of the plate elements. Finally we will also specify that the terms "upstream" and "downstream" refer to the meaning of scrolling of plate elements in the production machine.

The invention will be better understood when studying an embodiment taken in no way as a limitation and illustrated by the figures appended in which:

Figure 1 is a perspective view of the device of the invention seen from the driver side of the machine downstream, in accordance in the direction of movement of the plate elements.

Figure 2 is a perspective view of the mechanism illustrating the kinematic chain of the device of the invention seen from the same angle.

Figure 3 is a top view of the device of the invention.

Figures 4 and 5 are side views from the side conductor, of the mechanism of FIG. 2 respectively when the shutter of stopper is closed, and when open.

Figure 1 provides a general view of the device 1 for the longitudinal alignment of elements in plate 2, moving in the direction indicated by arrow 3 currently located on the longitudinal axis of the machine. The plate element 2, illustrated in phantom, is only partially represented by its downstream part and has an asymmetrical curl whose curvature is visible from the driver's side. Device 1 includes two shelves 5 and 6 folded down at an optimal angle and along an oblique line 7, so to constitute, for the most heavily tiled plate elements, two ramps to a margin table 8 illustrated schematically downstream by a mixed line. The outer edges of shelves 5 and 6 are maintained respectively against the side consoles 9 and 10 of the device 1, and the edges interiors are fixed against two external bearings 11 and 12 held in the frame not shown of the packaging production machine. Of them inner bearings 13, 14 support, together with the outer bearings 11, 12, two pulleys 15, 16 in their upstream end. Around these pulleys turn two belts 17, 18 (Figure 3) which allow to bring on the table margin 8 each plate element 2 successively introduced into the packaging production machine.

Upstream on the front parts of the two side consoles 9 and 10, slide vertically, in grooves 20, two bearings 21, 22 which can be locked there independently of each other by tightening a screw terminated by a handle 23. Between these two bearings is mounted a shaft 24 articulated by four universal joints 25 better visible in FIG. 2. This shaft Gimbal 24 consists of three segments, i.e., two side segments 27 and 28 and a central segment 26 supported by the bearings 13, 14. Thanks to the vertical displacements of the bearings 21, 22, it is possible to easily modify, within a certain range, the inclination of the lateral segments 27, 28 pivoting around the two inner gimbals 25. Although this setting is made manually using the handles 23, it will be mentioned that it could be automated, even enslaved, depending on the unwelcome curl of the leaves which is likely to vary throughout production.

Each segment of the PTO shaft supports an oriented flap upstream towards the downstream front edge of the plate element 2, so that the three flaps 30, 31, 32, rigorously aligned, constitute a stop transverse plane for the longitudinal alignment of the sheet 2. In the figure 1, the flaps are shown in a so-called closed position, ie in position vertical so as to oppose the passage of the element in plate 2 and thus constitute the alignment stop. The central flap 30 is attached against the central segment 26 thanks to two supports 33 visible in FIG. 3. These supports are screwed on the upper part of the central segment, symmetrically about the longitudinal axis of the machine, on flat 34 machined by milling (figure 2). The central flap 30 is finally fixed against these supports using screws 35. The two side flaps 31 and 32 are held against the respective segments 27, 28 by screws 36 passing through and tightening flanges 37 regularly spaced on these segments.

The upper corners of the shutters are rounded, particularly pronounced for the outer corners of the side flaps 31, 32, thus ensuring maximum clearance for the passage of a sheet strongly tiled. The central flap 30 has a horizontal rectilinear upper edge, thus an opening 38 formed in its upper middle part. This opening allows the passage of an optical beam from a sensor, not illustrated, placed on the longitudinal axis of the machine downstream of the central flap. This sensor adjusts the height of the stack relative to the device allowing the longitudinal alignment of the sheets, which allows the introduction one sheet at a time on the margin table. The side flaps 31, 32 are identical and have a trapezoidal shape such that by adjusting the height of their outer end by means of the vertical displacement of the bearings 21, 22 corresponding, it is possible to align the upper edge of these flaps with that of the central flap, thus defining a rectilinear horizontal line. This configuration is illustrated in figure 1 by flaps 30 and 32 opposite side driver. The trapezoidal shape of these side flaps is also machined such that when the height of their outer end is at the point the lower, their lower edge is parallel to the adjacent edge of a plate of protection 39 fixed by screws 40 (Figure 3) to a body not shown connected to the frame of the machine. This second configuration is shown in Figure 1 by the flaps 30 and 31 on the driver's side, which then follow the outline of the protective plate 39 by minimizing the interstitial space.

Figure 2 illustrates the mechanism defining the kinematic chain of the device of the present invention. The positions occupied by the various illustrated elements are strictly identical to those taken by the same elements in Figure 1. So that the flaps of the device 1 can alternately lower themselves, with the intention of allowing the passage of the element in plate 2, and get up to align the next element, it is necessary that the cardan shaft 24 is itself animated by this same movement varying within a determined angular range, preferably chosen between 0 and 45 degrees towards the direction of movement of the elements in plate. This alternating movement is governed by a control lever 41 placed at the driver side end of a drive shaft 42. The latter is kept in rotation by the bearing 14 and by the side console 10 in which is another rolling bearing. The alternating movement of the lever 41 is given by the cam 43 mounted on a shaft 44 which is driven in continuous rotation by a device, not illustrated, synchronized with the scrolling speed of the plate elements.

As best seen in Figures 3, 4 and 5, the particular shape of the cam 43 is read by a reading roller 45 mounted at the end of an arm 46. The opposite end of this arm is rigidly fixed to the terminal part, opposite conductive side of the shaft 42 so that the rotary movement arm 46 can be transmitted to the control lever 41. Ended with a articulation 47, the control lever 41 oscillates from a high position to a low position, and vice versa, around the axis of the driveshaft 42. Freely mounted in rotation, a pull tab 48 connects the joint 47 to the joint 49 firmly held on the central segment 26 of the cardan shaft. The zipper 48 constitutes the central transmission element of a joint acting on the segment 26 of the cardan shaft, inducing a moment, alternately in one direction then in the other, which rotates the entire shaft 24 so as to be able to lower and successively raise the flaps 30, 31 and 32.

To compensate for backlash in the kinematic chain and ensure cam control, two tension springs 51, 52 connect respectively the lateral segments 27 and 28 of the cardan shaft with the pins 53 fixed rigidly against the outer face of the bearings 11 and 12. The upstream end of these springs is held on a bearing placed between a spring clip 55 and a spacer 56 tightened together by a screw 57. As better visible on Figure 2, the spring clip is attached to it, like the flanges 37, to the corresponding side segment of the PTO shaft. Housed in shelves 5 and 6 above the springs, two openings 58 allow these last to evolve freely.

Figures 4 and 5 are side views, viewed from the side conductor, of the mechanism of FIG. 2 respectively when the flaps 30, 31, 32 are in the closed position, and when they are open. These two figures allow to better represent the movements of the parts of the mechanism which actuate the lowering and raising of the flaps of the device according to the invention.

Many improvements can be made to this device within the scope of the claims.

Claims (9)

Device (1) for the longitudinal alignment of plate elements (2) in an insertion station of a working machine, held by two side consoles (9, 10) between which there is in particular an access ramp for said plate elements, formed of two shelves (5, 6) folded down along a line (7) not perpendicular to the direction of movement (3) of said elements (2) led downstream by at least two strips of transport (17, 18) rotating around at least two pulleys (15, 16) held between stationary bearings (11, 12, 13, 14) at the entrance of said device (1), which has a plate at the front protection (39) above which are flaps (30, 31, 32) foldable and secured to a transverse shaft (24) which connects the front ends of the two side consoles (9, 10) and which is animated of an alternating rotary movement, between 0 and 45 degrees, synchronized with the production speed of the mach ine to allow the successive alignment of said plate elements (2), characterized in that it is equipped with a shaft (24) articulated and consisting of several segments (26, 27, 28) supporting each of them a said flaps (30, 31, 32). Device according to claim 1, characterized in that the shaft (24) is articulated by means of cardans (25) connecting together said segments (26, 27, 28), as well as the ends of the shaft (24) to movable bearings (21, 22) adjustable independently of one another in the vertical plane. Device according to claim 1, characterized in that the central segment (26) is supported horizontally by the stationary bearings (13, 14) at a height such that the upper edge of the flap (30) is substantially at the same height as the conveyor belts (17, 18) when the flap (30) is in a vertical position called closed, and below this height when it is in oblique position called open. Device according to claim 2, characterized in that the mobile bearings (21, 22) slide vertically in grooves (20), arranged at the ends of the side brackets (9, 10), which thus allow the ends of the shaft to be moved (24) in a range extending from a level situated above the central segment (26), to a level situated below this same segment. Device according to claim 4, characterized in that the displacement of the mobile bearings (21, 22) takes place, either manually after loosening of a screw terminated by a handle (23) tightening each of the bearings against said corresponding groove (20) , or either automatically by any actuator which can be controlled as a function of the degree of curling of the plate elements (2) introduced into the working machine. Device according to claim 1, characterized in that said flaps (30, 31, 32) are fixed permanently, rigidly on the articulated shaft (24), and in a symmetrical manner relative to the longitudinal axis of the machine . Device according to claim 1, characterized in that the flaps (30, 31, 32) are all located in the same vertical plane when they are raised, in the so-called closed position. Device according to claims 2 and 3, characterized in that the side flaps (31, 32) are identical and have a trapezoidal shape such that by adjusting the height of their outer end by means of the vertical displacement of the bearings (21, 22) corresponding, it is possible to align the upper edge of these flaps with that of the central flap (30) thereby defining a rectilinear horizontal line, and that in this configuration, the universal joints (25) of the lateral flaps (31) , 32) are located at a level higher than that occupied by the central segment (26). Device according to claims 2 and 3, characterized in that the trapezoidal shape of the side flaps (31, 32) is also machined such that, when the height of their outer end is at the lowest point, their lower edge is parallel to the adjacent edge of the protection plate (39).

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