MACHINE FOR OPENING TRAY WITH OVERLAPING FOLDED SIDE WALLS

Description

[0001] The invention relates to a machine for opening the folded side walls of crates, wherein at least the side walls lying on the bottom of the crate overlap.

[0002] EP 2 181 841 B1 by the same applicant discloses a machine for the mechanized opening and closing of the foldable side walls of plastic crates used for the transport and storage of fruit or vegetables. The height of the side walls of said crates is less than half the length of the shorter side of the crate, which is why, in the folded or closed position, the two transverse walls extend in the same plane and both rest against the base of the crate, while the two longitudinal walls, in the closed position, also extend in the same plane and rest against the transverse walls. These non-overlapping transverse walls are gripped by gripping hooks that move horizontally in opposite directions on a vertically movable support rail and are pivoted into the vertical opening position.In order to be able to grasp the cross walls lying on the bottom of the crate with the said gripping hooks, these press the bottom of the crate vertically downwards in order to be able to engage under the upper edge of the cross walls during this elastic deformation of the bottom.

[0003] Crates with foldable walls of the above-mentioned type are known in which, due to the height of the side walls being greater than half the length of the crate, the individual walls belonging to the same pair assume an at least partially overlapping position when folded or closed. This type of crate cannot be opened mechanically with the machine mentioned in EP 2 181 841 B1 or with similar machines in which, in particular, the pair of walls which usually run transversely or which rest against the crate base when closed, can be opened mechanically, because the gripping elements which are attached to the upper free edge of the two walls in question cannot be inserted between the folded, overlapping walls in order to open them.

[0004] IT BZ20010045 A1 discloses a method and a machine for the automated opening of various crate models with foldable side walls. In particular, this method provides for the overlapping transverse walls, which are perpendicular to the feed direction of the crate, to be elastically deformed upwards from below by a pneumatic or hydraulic cylinder or mechanically before the corresponding opening gripping hooks, which engage the upper edge of the transverse side walls, are actuated.This loading and deformation of the tray base, which is held laterally between the sliding guide rails in the processing area in a known manner, occurs in an area somewhat spaced from the hinge axis of the cross walls and causes the area of ​​the upper edge of the overlapping cross wall adjacent to the tray base to lift off the ground. Because the cross wall rests on the base deformation and pivots according to the hinge axis, it assumes a position angled to the ground. The upper edge of this cross wall is lifted from the overlapped second cross wall and from the tray base and can thus be grasped by the opening gripping hook. Of course, the overlapping cross wall opens in a first phase, and only then does the second (overlapped) cross wall open.This method places mechanical stress on the tray base, and the resulting distance between the upper edge of the cross wall and the tray base is not always constant due to the varying deformation of the tray base and / or the fact that the base is not always held securely between the sliding guides, which impairs the gripping reliability of the opening grab hooks.

[0005] The invention has for its object to provide a machine for opening crates of the above-mentioned type in which at least the walls running transversely to the feed direction of the crate, which walls rest on the crate base and lie under the pair of longitudinal walls, overlap.

[0006] Said crates have holes or openings in the bottom for the drainage of any water or for the ventilation of the contents. The opening of the walls of the upper, usually longitudinal pair of walls is essentially carried out in the manner described in EP 2 181 841 B1, by means of lateral pressure elements supported by pivoting arms. However, since the pivot axis of these arms is not coaxial with the corresponding hinge axis of the walls, the invention provides for the interposition of pivoting or sliding elements between the pivoting arms and the respective pressure element to compensate for movement, thereby preventing the walls from being subjected to excessive stress during the opening phase.The said compensating elements, which are pivotally or slidably mounted on the pivot arms, are provided with a spring which, when charged during the opening movement, returns the said compensating element together with the pressing element to a stop so that it once again assumes the exact position for clamping the wall of the crate which is next brought into the opening position. For the subsequent opening of the walls of the pair of walls adjacent to the crate base, the invention utilizes the presence of the said openings to partially raise the two walls by means of plungers which penetrate the said openings vertically from below and act directly on these walls without loading the crate base, so that the known opening gripping hooks cited in the same patent can access the upper free edges of the said walls, which are partially raised and sufficiently spaced apart from one another.Since the rams do not load the crate base and therefore do not affect the position of the crate held in the processing area, a constant position of the upper edge of the partially raised side wall is always achieved, which ensures the gripping security of the opening gripping hooks.

[0007] In order to be able to control the opening elements and the said rams in a suitable manner, the machine according to the invention is equipped at the inlet with a known photographic acquisition station with image recognition, which is suitable for providing data relating to the position of the hinge axis of the overlapping wall belonging to the upper pair of walls of the individual supplied trays and visible from above, or accessible via the photographic acquisitions. In practice, the data relating to the determination of the supplied tray model and the position of the hinge axis of the overlapping wall of the upper, visible pair of walls are sufficient to also determine the position of the overlapping wall of the lower pair of walls adjacent to the tray base.By opening the walls of the upper pair of walls in a known manner by means of pivoting pressure elements that act mutually on the lateral edges of the walls, whereby the overlapping wall and subsequently the wall below it are pivoted upwards with a suitable projection, the opening of the underlying pair of walls, which usually run transversely to the feed direction, takes place. According to the invention, this opening takes place in a first phase by vertically actuating rams that penetrate holes or openings in the tray base without loading or deforming it, so that first the overlapping wall and then the overlapped wall are lifted.As soon as these walls assume an angled position such that their free upper edges are sufficiently spaced from one another, the two opening gripping hooks known from EP 2181841 B1 are actuated to cause the complete opening and snapping of the connecting device onto the corresponding previously opened walls and to secure the walls in the open position. Advantageously, the machine uses conveyor belts for transferring the crates, which act laterally on the bottom of the crates resting on longitudinal guide rails. In the case of damaged crates or jams caused by damage, the said belts are moved or pivoted together with the guide rails in such a way that they are spaced from one another, causing the damaged crate to be rejected as it falls through downwards.In order not to hinder this fall of the crate, the cylinders for actuating the opening plungers are mounted so that, in the case of a crate to be rejected, they are moved laterally out of the fall area of ​​the rejected crate before the distancing movement of the conveyor belts in order to then be able to resume their active position under the bottom of the subsequently conveyed crate.

[0008] According to the invention, the crates can be fed into the machine in a longitudinal or transverse position. The separation of damaged crates or crate models that cannot be processed can also be achieved in a known manner by pushing them onto separate belts or chutes. In this case, the rams acting through the openings in the crate base can always maintain their active position under the crate. It is, of course, possible for only one ram to act on each wall of the pair of walls adjacent to the crate base.

[0009] The invention will now be explained in more detail with reference to a preferred embodiment of a machine for the mechanized opening of crates with foldable, overlapping side walls, which is schematically illustrated in the accompanying drawings; the drawings are for purely explanatory and non-limiting purposes.

[0010] The Fig. 1 is a perspective view of a machine according to the invention for opening the foldable, overlapping side walls, which is equipped with spaced-apart conveyor belts and lateral sliding guides for the rejection of damaged crates.

[0011] The Fig. 2 is a sectional view according to a vertical section plane across the Fig. 1 shown machine, the cutting plane runs through a central area of ​​the machined tray during the opening chamfer of the walls parallel to the conveying direction of the tray, by means of known counteracting, pivoting pressure elements.

[0012] The Fig. 4 is a sectional view according to a vertical section plane along the Fig. 1 shown machine, the cutting plane runs through a central area of ​​the machined crate during the opening bevel of the walls running transversely to the conveying direction of the crate, with the rams in the ejection position and with both known opening gripping hooks in the gripping position on the upper free edges of both transverse walls.

[0013] The Fig. 5 shows the same in Fig. 4 shown longitudinal section with the transverse walls in maximum opening position.

[0014] The Fig. 6 is a perspective view of a crate of the type with overlapping walls in the closed position, seen from below, with the longitudinal walls in a partially open position; at the bottom, the openings are visible through which the pushers can act to partially open the transverse walls so that the opening hooks can subsequently be inserted under the free upper edges of said walls.

[0015] The Fig. 7 is a perspective side view of the Fig. 6 shown climbs with the fully open longitudinal walls and the partially open transverse walls.

[0016] The example shown in the Fig. 1 bis Fig. 5The machine shown uses various design and functional features of the machine described in EP 2 181 941 B1, the innovative feature essentially consisting in the use of the plunger 6d for opening 10y the walls 10q which overlap and rest against the bottom 10b of the tray 10 and in the different actuation of the individual opening devices, which are known per se.

[0017] Two 2s units 2 are hinged 2a to the frame 1, pivotable by motor 2m. These are equipped with a conveyor belt 2b acting on the edge of the floor 10b of the tray 10. Photographic image recognition is used to define the tray model and the position of the overlapping, usually visible from above, longitudinal wall of the pair of walls 10s. From these elevations, it is possible to define the position of the hinge linkage of the overlapping wall, the underlying pair of walls 10q, which rests on the floor 10b of the tray 10.

[0018] The bottom of the tray 10 being processed rests during its transfer 10a on parallel longitudinal guides 2c, which are movable 2s together with the pivoting 2s unit 2.

[0019] As soon as the crate 10 reaches the processing area, it is blocked in a known manner by the stationary conveyor belts 2b and / or by cylinders acting laterally on the guide rails for the crate base. Based on the previous image recognition, the profile 3 is actuated 3s by the pivoting arms 3b via the compensating elements 4 pivotally mounted thereon 4s. The compensating elements 4 are provided with opposing pressing elements 5, between which the overlapping longitudinal wall 10s of the upper pair of walls visible from above is clamped 5h in a first moment in order to open 10x this wall 10s by pivoting 3s upwards the pivoting arms 3b linked to the unit 2 provided with the conveyor belt 2b.Since the pivot axis 3a of the pivot arms 3b does not correspond to the hinge axis 10z of the walls 10s at the bottom of the tray 10, the said pressing elements 5 are carried by the curved pivot arms 3b with the intermediate support of a compensating element 4s pivotable about the bearing axis 4a. The invention does not preclude the said compensating movement being achieved by the pressing elements 5 being slidably mounted on the arms 3b and, if appropriate, being provided with roller elements which are pressed against the lateral edge of the wall 10s to be opened. The movement of the compensating element 4s is controlled, with respect to the respective pivoting arm 3b, by a spring which is loaded during the opening movement of the side walls 10s in order to return the pressing element 5, after the opening of the wall, to a stop which determines the exact position of the pressing element 5, in order to be able to clamp the wall 10s of the following crate 5h.Preferably, as soon as the overlapping wall 10s is slightly raised, the pair of pressing elements 5 of the second pivoting arms 3b together with the compensating elements 4 clamps the second (overlapped) wall 10s in order to open it 10x, without colliding with the first, already sufficiently opened wall 10s.

[0020] Once the upper (visible) pair of walls 10s is in the fully open position, the 6v pushers 6d, moved by the corresponding pivoting cylinders 6s, come into operation. Said cylinders 6c act between the frame 1 of the machine and an arm 6b pivoted 6s on the frame 1. On each of these arms 6b, at the end opposite the pivoted end, a vertical cylinder 6 is attached for moving 6v a pusher 6d. Said pushers 6d, together with the corresponding vertical cylinders 6, are arranged, in the active position, vertically below the corresponding openings or holes 10f provided in the bottom 10b of the tray 10, held in the working position between the conveyor belts 2b.Once the opening 10x of the upper walls 10s has been completed, the pair of pushrods 6d positioned vertically below the holes 10f in the base 10b of the tray 10, corresponding to the position of the overlapping wall 10q of the pair of walls adjacent to the base 10b, is actuated 6v to penetrate said holes without stressing the tray base or the corresponding retaining mechanisms and to partially raise 10y said overlapping wall 10q. Subsequently, the second pair of pushrods 6d positioned vertically below the holes 10f corresponding to the overlapped wall 10q is moved 6v to partially raise this wall.Once the upper free edges of the two said partially opened walls 10q are sufficiently spaced from each other and raised from the bottom of the crate, the opening gripping hooks 9 are actuated in a known manner by being brought into the hooking position along the vertical column 7 by means of the horizontal arm 8, which is vertically movable by means of a motor 7m, in order to complete the opening of the transverse walls 10q by moving them 9h in the opposite direction along the said horizontal arm 8 during its lifting movement 8v. During the said opening operation of the pair of walls 10q, the vertical pushers 6d can be retracted 6v. In the event of a malfunction during the opening operation of the walls, the cylinders 6 are pivoted 6c by means of cylinders 6c into a position resting on the frame 1 of the machine by means of arms 6b articulated to the frame.retracted by means of arms mounted on the frame, sliding transversely to the conveying direction 10° of the trays 10, so as not to hinder the ejection of the tray 10 by its free fall 10v, caused by the pivoting apart 2s of the units 2 equipped with conveyor belt 2b and guide rail 2c. The said retracted position of the cylinders 6 with ram 6d is also assumed when the machining area is reached by a tray which is recognized as belonging to a type not machineable by the machine, in order to eliminate it by spacing the units 2 by pivoting 2s or shifting.

[0021] Naturally, the mechanical opening devices 3, 3b and the pneumatic or hydraulic opening devices 5, 6 are controlled based on the right or left position, relative to the conveying direction 10a of the tray 10, of the pivot axis 2c of the overlapping wall of the upper, visible pair of walls 10s. This position, which is acquired in a known manner using image recognition and possibly recognition of the tray model, also allows the definition of the (front or rear) position of the pivot axis 10r of the upper wall of the pair of walls resting against the bottom 10b of the tray. To prevent collision between the walls during opening operations, priority is always given to at least partial opening of the overlapping walls.

Claims

1. Machine for opening crates (10) that have overlapping folded side walls (10s, 10q), to which machine the crates are fed following ascertainment of the type of crate and the position of the pivot axis (10z) of the overlapping wall of the upper pair of walls (10x) visible from above, said machine consisting of a pair of conveyor belts (2b) which act laterally on the opposite edges of the bottom (10b) of the crate (10), parallel guides (2c) on which the crate to be processed slides, pivotable (3s) arms (3b), which are provided with pressing elements (5), for fully opening (10x) the pair of upper walls (10s), and opening gripping hooks (9), which are movable (9h) in opposite directions and are mounted on an arm (8) that is vertically (8v) movable along a pillar (7), for opening (10y) the pair of walls (10q) resting on the bottom (10b) of the crate (10), characterized in that, for a first phase of opening the pair of walls (10q) resting on the bottom (10b) of the crate, at least one ram (6d) is provided for each of these in a position beneath the crate (10) to be processed, said ram being able to be actuated (6v) vertically (6v) by a pneumatic or hydraulic cylinder (6), in that the rams (6d) are fixedly arranged vertically beneath one of the holes or apertures (10f) provided on the bottom at a distance from hinge axis (10r) on the walls (10q), and in that, by extending the rams (6d), the latter act (6v) directly on the walls (10q), through said apertures, without loading the crate bottom (10b) or the corresponding holding mechanisms, in order to achieve partial opening (10y) of the walls (10q).

2. Machine according to claim 1, characterized in that, in the case where crates (10) are rejected by freefalling (10v) downwards, which is achieved by spacing apart the conveyor belts (2b) together with the sliding guide rails (2c) by pivoting (2s) or moving the conveyor units (2) in opposite directions, the cylinders (6) are movable (6s) pneumatically, hydraulically or mechanically for moving (6v) the rams (6d) from an active position vertically beneath the apertures (10f) on the crate bottom to a passive position outside the area occupied by the falling (10v) crates (10).

3. Machine according to claim 1, characterized in that the cylinders (6) for actuating (6v) the rams (6d) are slidably mounted on the frame (1) of the machine by means of cantilevered arms in order to be able to be moved, by means of pneumatic or hydraulic cylinders (6c), from an extended active position to a retracted passive position outside the area through which the discarded crates (10) fall (10v).