EP0453983B1 - Device for interception of sheets set down on top of a pile in a package forming machine - Google Patents

Abstract

A device having a movable grid mounted on a movable carriage to temporarily intercept sheets being deposited from a machine for processing the sheets being discharged into a pile from a machine for processing the sheets includes an arrangement of a planetary system comprising a pinion movable in a circular arc coacting with a rim gear rigidly mounted on a frame and an arrangement for connecting the pinion to the carriage so that as the pinion rotates in the circular arc, the carriage is shifted between a retracted position and a second position for intercepting the sheets being deposited in pile. The device is particularly useful in a delivery station for a machine for die cutting package blanks in sheets of material.

Description

The present invention relates to a device for intercepting sheets deposited on the top of a stack in a packaging production machine, in particular in a machine for working elements in the form of plates or sheets, machine performing operations such as cutting, upsetting and / or printing for the production of packaging. The device makes it possible, during the formation of a stack of sheets, to temporarily intercept and receive the sheets, while they are deposited one by one on the top of the stack.

The patents CH-A-359593 and DE-A-1611776 describe a device intended to intercept sheets being dispensed on the top of a stack. Here, the solid intermediate grid is replaced by a flexible screen that can be rolled out over the stack and on which the new stack can temporarily rest. Once the complete stack has been removed, the flexible screen can be rolled up in the other direction in order to be removed from under the new stack so that it can rest, for example, on a table that can be moved vertically.

Whether in the case of the solid grid or the flexible screen, their displacement in one direction or another has always been to date essentially carried out by means of chains driven by a motor. However, given the relatively large stroke to be performed which can go up to 1200 mm and the current high production rates which may require, for the grid or the screen, maximum displacement speeds of 6 m / sec, the control of such chain means for alternating movements in one direction and in the other is difficult, a source of trouble by breaking chains, and imprecise since it is difficult to master breakpoints or reversals.

Devices are already known for transforming a rotary movement into a linear movement allowing the chains to be replaced by gears. French patent N ° 1519699 relates to such a device which, according to this publication comprises two internal toothed crowns in which mesh two planet gears driven in rotation in the crowns by the action of a connecting rod acting on crank pins integral with each of the gables. In this example, the linear movement of the connecting rod is transformed into a rotational movement applied, via a crankshaft, to a crankshaft axis. It is therefore a question here of transforming a linear movement into a rotary movement.

By design, this device can of course be used to transform a rotary movement into a linear movement.

Obviously, this kind of device is designed to admit the very high rotational speeds encountered in thermal engines and therefore its construction is relatively expensive and its use as such would not be judicious for rotational speeds. of relatively modest importance.

French Patent No. 1532130 relates to a sheet stacking device comprising a receiving plane and an auxiliary plane, in the form of forks, animated by a linear movement. The auxiliary plan is intended to receive the sheets coming from a sheet cutting machine during unloading of the stack of sheets having been stacked on the receiving surface. In this publication, the linear movement of the two planes is obtained by means of an assembly comprising an eccentric acting on levers recalled in position by means of springs, the triggering of the linear movements being caused by a member combining cams and levers.

This device, however, has great complexity preventing good operating precision due to the mechanical solutions adopted for its production.

The object of the invention is to overcome the existing drawbacks by proposing a device in accordance with what is stated in claim 1.

Such a device can be used, for example, as shown in Figure 1 of the accompanying drawing, in a so-called sheet reception station and located at the outlet or following a cutting press. In this station, the sheets F, which exit one by one from the press P₁, are transported by gripper bars B₁ mounted on a chain of chains C₃, and successively deposited one on the other to form a stack E₁. When the stack is complete, it is known to insert very quickly, that is to say during the very short time which elapses between the last sheet deposited on the top of the stack and the next, an intermediate grid 45 which will cover the top of the stack and on which a new stack can temporarily start. During this time, the entire stack can be removed from the receiving station. For the formation of the battery, the station is equipped with a battery holder provided with a table T₁ in the form of a vertically movable grid. In sight of the reception of the sheets (or sides, in the case where the reception station is associated with the operation of separation of the poses which consists in breaking the points of attachment which maintain between them the different poses of the same sheet at the output of the cutting press), the table T₁ which, at the start of stack formation, is lower than the sheet F which arrives from the press, then lowers, as the height of the stack E₁ increases, so as to maintain its vertex at constant height. To facilitate the evacuation of the battery, the movable table T₁ is mounted on the upper end of a vertical upright M₁ located between two conveyor belts C₁; once the stack is complete, it suffices to lower the vertical upright M₁ enough so that the bottom sheet of the complete stack E₂ can bear, through the openings of the grid forming the movable table T₁, on the two conveyor belts Who will transport her out of the station. Once the E₂ stack has been removed, the grid or table T₁ is again moved upwards in contact with the new temporarily formed E₁ stack and bearing on the interposed grid 45. To be able to substitute for the support effect of the grid insert 45 that of the table T₁, it is known to provide that the grid elements of the latter T₁ can project over the grid through corresponding openings (as shown in broken lines T₁ ′). In reality, the intermediate grid 45 can be compared to a fork between the teeth from which the support elements of the table T₁ protrude and which, once released from the weight of the new stack, can be easily removed from below the pile, this in the direction of the teeth for allow, between their free ends, the escape of the support elements of the table T1 relative to the fork or intermediate grid 45. It should be noted that all the operations mentioned above can be carried out without stopping the machine.

• la figure 1 est une vue de dessus d'un dispositif selon l'invention;
• la figure 2 est une vue de côté en coupe selon A - A de la figure 1; et
• la figure 3 est une vue de côté en coupe partielle d'une station de réception de feuilles, située à la suite d'une presse de découpage.

Other characteristics and advantages of the invention will now emerge from an embodiment of the invention described with reference to the appended drawing in which:

• Figure 1 is a top view of a device according to the invention;
• Figure 2 is a side sectional view along A - A of Figure 1; and
• Figure 3 is a side view in partial section of a sheet receiving station, located after a cutting press.

The sheet interception device comprises a fixed horizontal rectangular frame C consisting of two side plates 10, 10 ′, a transverse plate 11a and transverse profiles 11b-11h. The plates 10, 10 ′, 11a and the sections 11b-11h are joined together at their ends by means of screws 12. If, in FIG. 1, it is considered that the sheets arrive from an earlier station situated on the right, by example of a waste ejection station of a cutting machine, the dimensions of the frame C are large enough that the two side plates 10, 10 ′ are each located on one side of the stack to be formed. At its four ends, the frame C is provided with brackets 14 for fixing to the frame B of the machine. Inside the left end of the frame C, that is to say the far end of the stack, is mounted horizontally a large crown with internal teeth 20. The crown 20 is fixed, at using screws, on the underside of the transverse profiles 11b-11h. For construction reasons, spacers 16 are interposed between sections 11b, 11g, 11f and the crown 20. A movable pinion 30, the number of teeth of which is equal to half that of the crown 20, is mounted on the inside and in contact with the teeth of the latter. The pinion 30 is mounted in free rotation on a pin 31 fixed on the first end of a horizontal lever 32 whose other end is fixed on a vertical output shaft R de of a reduction gear R coupled to a motor M. L ' assembly constituted by the reducer R and the motor M is fixed, by means of screws 33, on a plate 34 (not shown in Figure 1 to facilitate understanding) welded to the underside of two transverse sections 11g, 11f.

Below the crown 20 is a carriage 40 movable horizontally in the left-right direction and vice versa. The carriage 40 consists of a transverse section 41 provided at each of its ends with a horizontal bar 42, respectively 42 ′, extending parallel to the corresponding side plates 10, 10 ′. Each bar 42, 42 ′ is provided with two rollers 48, 48 ′ engaged with a guide groove formed by two bars 43, 43 ′ respectively, provided on each side plate 10, 10 ′. Several U-shaped profiles 45 are mounted on the profile 41. The profiles are fixed at one end to the profile 41 so that together they have a support in the form of a fork (as mentioned above) intended to be moved over the entire stack to temporarily intercept and receive the sheets.

On the middle of the transverse section 41 is mounted in free rotation, using a bearing 47, a vertical pin 44 whose upper end is in engagement with a fixing block 35 fixed on the underside of the pinion 30. FIG. 1 shows the instant when the carriage 40 is at the end of its travel at the left end, ie at the moment when the U-shaped profiles 45 are completely out of the top of the stack, i.e. are not in a condition to intercept the sheets. At this instant, the two pins 44, 31 and the axis of rotation of the vertical shaft R₁ of the pinion 30 are on a single straight line, namely on the central axis O₁ of the machine, the axis the pin 44 located on the point of tangency of the pinion 30 relative to the crown 20. When the lever 32 is rotated, for example clockwise, by the shaft R₁ driven by the motor M, the reaction of the crown 20 fixed on the movable pinion 30 forces the latter to rotate in the anticlockwise direction. Given that the diameter of the pinion 30 is equal to half that of the crown 20, the pin 44 will move to the right along the central axis O₁ and also carrying with it the carriage 40 whose guidance is ensured by the rollers 48, 48 ′ and the guides 43, 43 ′. The end of travel to the right of the carriage 40 takes place when the point of tangency between the pinion 30 and the crown 20 is again on the central axis O₁ but on the right side of the crown 20. This instant therefore corresponds to the moment when the U 45 profiles are advanced as far as possible over the stack and ready to intercept and temporarily receive the sheets.

At this instant, the engine M is stopped, and the complete stack E₂ located below the sections 45 is evacuated, that is to say removed from the movable table T₁ from the battery holder mentioned above. The table T₁ is then moved upwards until its support elements (also mentioned above) protrude, between and over the U-shaped profiles 45 so as to release the latter from the pile E₁ temporarily formed on them. Then, the motor M is restarted to bring the carriage 40 to the left, that is to say to bring said point of tangency to the starting point, that is to say to the left side of the crown 20 so that the U-profiles can no longer intercept the sheets.

It is obvious that, in order to reduce the mass inertias, all the sections 41, 45 constituting the carriage 40 are made of light material, for example, of aluminum alloy.

Figure 3 shows how the frame C of the device is arranged below the return location of a chain train C₃ on which are clamped bars B₁ engaged with the front edge of the sheets. The sheets F are brought, from a cutting press P₁, above the place where a stack E₁ (or E₂) is being formed. The stack E₂ is a complete stack which has just been lowered onto two conveyor belts C₁. A battery E₃ is being evacuated on two bands C₂. The intermediate grid 45 is shown in solid lines in a first position where it is located completely outside of the top of the stack E₁. Until this moment, the leaves F have therefore fallen onto the stack E₂. At the moment when the intermediate grid 45 is advanced into position 45 ′ (in broken lines), a new stack E₁ is provisionally formed on it. When the stack E₂ has been transported by the bands C₁ on the bands C₂, that is to say outside the table T₁, this can be transported upwards to the position T1 ′ (in broken lines) so as to emerge slightly at- above the intermediate grid 45 ′ to take up the weight of the stack E₁. At this instant, the intermediate grid can be brought back to position 45. Then, the table T₁ will be gradually lowered as the thickness of the stack E₁ increases, so that its top is always kept at constant height.

• pas de transmission par chaînes;
• grande précision dans le positionnement en fin de course du chariot 40; en effet, même une légère erreur angulaire dans le positionnement du pignon 30 lors des deux positions extrêmes de la course du chariot 40, c'est-à-dire à l'instant où le point de tangence du pignon 30 avec la couronne 20 doit se trouver sur l'axe central O₁, n'entraîne qu'une infime erreur linéaire de positionnement du chariot 40;
• grande simplicité de construction pour un fonctionnement rapide et sûr.

The device described above therefore has the following advantages:

• no chain transmission;
• high accuracy in positioning the end of travel of the carriage 40; indeed, even a slight angular error in the positioning of the pinion 30 during the two extreme positions of the stroke of the carriage 40, that is to say at the moment when the point of tangency of the pinion 30 with the crown 20 must being on the central axis O₁, causes only a tiny linear positioning error of the carriage 40;
• great simplicity of construction for fast and safe operation.

Claims (5)

1. Device which allows, in a machine processing sheet-shaped workpieces, to intercept and temporarily collect the sheets being laid down one by one on a pile, and which includes a sheet interception device comprising a fixed part (C) which is fitted on the frame (B) of the machine as well as a movable part (40) provided with a fork-shaped support (41, 45) able to take up a first position in which the said support (41, 45) is located on a side of the pile building up and, similarly, a second position in which the said support (41, 45) is located above the pile and thus able to intercept the sheets, means for shifting the movable part (40) from the first to the second position mentioned, and means (43, 48) for guiding the movable part (40) with regard to the fixed part (C), the said interception device being driven by a horizontal rim (20) with inner teeth which is engaged with a movable pinion (30) whose teeth are permanently engaged in those of the rim (20) and the number of teeth of which is equal to half of the one of the rim (20), whereas the said movable pinion (30) is connected to the movable part (40) by linking means (47, 44, 35) characterized by the fact that the rim (20) is fitted horizontally on the lower side of crosswise profiled pieces (11b-11h) of a rectangular and horizontal fixed frame (C), by the fact that the movable pinion (30) is fitted for free rotation on a stud (31) fitted at the first end of a horizontal lever (32) whose other end is fitted on a vertical outlet shaft (R₁) of a reduction gear (R) itself connected to a motor (M), the axle of the rim (20) being located on the central axis (O₁) of the machine, by the fact that the said movable pinion (30) is connected to the movable part (40) by a crosswise profiled piece (41) whose centre carries by means of a bearing (47) a vertical stud (44) for free rotation with an upper end held in a fixture (35) itself fitted on the lower side of the pinion (30), and by the fact that the said shift of the movable part (40) is achieved in a direction parallel to the one of the rear side of the sheet pile, ie along the central machine axis (O₁), the first and the second position mentioned of the movable part (40) being determined by the two positions of the pinion (30) in which its tangential contact point with the rim (20) is also located on the said central axis (O₁) of the machine.
2. Device according to claim 1, characterized by the fact that the fixed part (C) consists of a rectangular frame situated on the pile side opposite to the sheet arrival side and made up of lateral (10, 10′) and crosswise (11a, 11b) crossbars, the rim (20) being situated on the side of the frame (C) farthest from the pile so that the first and second position mentioned of the movable part (40) will correspond to the farthest or respectively closest ones of the pinion (30) with regard to the pile.
3. Device according to claim 1, characterized by the fact that the said fork-shaped support of the movable part (40) consists of a crosswise crossbar (41) and of several horizontal profiled pieces (45) fitted with one end to the said crosswise crossbar (41) and extending toward the pile essentially parallelly to the central axis (O₁) of the machine.
4. Device according to claim 1, characterized by the fact that the said guiding means include rollers (48, 48′) fitted on lateral supports (42, 42′) themselves fitted at each end of the crossbar (41) making up the movable part (40), the rollers (48, 48′) being connected to the corresponding guides (43, 43′) which are to be fitted on the fixed frame (C).
5. Device according to claim 3, characterised by the horizontal profiled pieces (45) being U-shaped and consisting of aluminum alloy.

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