MACHINE FOR SORTING AND STACKING CRATES WITH FOLDING SIDE WALLS

Description

[0001] The invention relates to a machine with high efficiency for sorting and stacking crates with folded side walls which, as a result of passing through a recognition station in which, by means of known image recognition systems and / or mechanical recognition systems, the crate model is recognized and, as a result of passing through a station for detecting defective crates, the crates are sorted according to crate model and stacked, wherein the defective crates are possibly eliminated before or after the stacking device.

[0002] In the centers where reusable crates with foldable side walls are washed, dried, sorted, counted, stacked and palletized, highly efficient stacking devices are required in order not to slow down the high work rhythm of the machines installed before and / or after the stacking and sorting machines.

[0003] From EP 3 865 223 A1 by the same applicant, a sorting machine for crates with closed or fixed side walls is known, containing the features of the preamble of claim 1, in which the crates are held back on the moving conveyor belt by a movably mounted stop member and are fed by a removal device to the stacking device arranged laterally of the conveyor belt. To prevent the crates from rebounding when they hit the said stop member, the latter performs a progressive braking movement in the conveying direction and / or is equipped with a damping device. The removal device consists of two mutually movable jaws which, in the open position, are lowered onto the crate held back by the stop member in order to clamp the crate between the jaws and move it sideways towards the stacking device, where it is dropped over the stacking chute provided with guide plates.The progressive braking of the crates against the stop device, or rather the cushioning of the impact against it, the clamping and release movement of the clamping jaws of the removal device, as well as the movement of the gripped crates from the conveyor belt to the stacking machine's shaft and the return of the clamping jaws to the removal position above the conveyor belt, require considerable time, which significantly reduces the machine's performance. Furthermore, it often happens that the crates dropped freely into the stacking shaft by the clamping jaws become jammed in the shaft inlet area or on the vertical guides of the stacking shaft due to the clamping jaws not working perfectly synchronously, the clamping jaws not always gripping the crates in the same position, and the not always precisely central position of the falling crates in relation to the stacking shaft inlet, despite the provided guide plates.

[0004] The invention has for its object to provide a sorting and stacking machine of the aforementioned type in which the passage of the individual crates with folded side walls, which are fed by a conveyor belt in the direction of the stacking device, takes place at high speed and without jamming.

[0005] To solve this problem, the invention proposes a machine according to claim 1. Preferred embodiments are defined in the appended claims.

[0006] A stacking device not according to the invention can be equipped with vertical guides with an L-shaped cross-section for holding the stack of crates fed from above, and with a vertically movable loading platform or loading fork which is movable between said guides for receiving the stack of crates. As each crate is fed, said loading platform or loading fork is moved downwards by an amount corresponding to the thickness of a crate with folded-down side walls until it reaches the bottom of the device. As soon as said loading platform or loading fork reaches the bottom of the device, the formed stack of crates is removed from the stacking device in a known manner and is usually fed to the palletizing process.

[0007] In the upper part of the stacking device, horizontal supports are provided, perpendicular to the conveyor belt, along the sides that run parallel to the conveying direction of the crates. These supports are equipped with vertical guides that can move between a retracted, inactive position outside the free vertical throughput of the crates to be stacked and an extended, active interception and retention position. The movement of these horizontal retention supports with the vertical guides is achieved via pneumatic or hydraulic, horizontally acting cylinder pairs.According to the invention, in order to avoid jamming or malfunctions caused by the not always synchronous action of the said cylinders, especially during high operating cycles, the cylinders are held at their base by means of elastic cushions, the ends of the corresponding piston rods are also held on the said horizontal supports with the vertical guides by means of elastic elements, while one cylinder of each pair is guided vertically by a fixed fork with its end provided with an elastic element opposite the cylinder base.

[0008] According to the invention, a vertically positioned stop plate is further provided in the upper region of the machine, on the side opposite the side where the crates to be stacked are fed in, which is pivotally mounted about an axis in the lower position, so that, as a result of the impact of a crate which has been moved transversely to the conveyor belt, it can assume an angled position controlled by a known damping element, consisting, for example, of a hollow body made of elastic material on which at least one possibly adjustable vent opening is provided. The said damping element causes the pivoting stop plate to yield in a controlled manner, whereby part of the impact energy of the crate is absorbed, the damping element is partially squeezed and then, as a result of the controlled expansion of the damping element, it can assume the vertical position again.The absorption of the impact energy and the return of the pivoting stop plate to its vertical position cause the crate to fall downwards without jamming and in a regular position. Its movement is guided by the vertical guides, which, together with the horizontal retention supports, assume the extended, active retention position for the crate being stacked. Only when a previously formed stack of crates is removed, or during the repositioning of the vertically movable loading platform or loading fork of the stacking device, do the horizontal retention supports, along with the corresponding vertical guides, remain in the retention position, with the option of retaining more than one crate.As soon as the vertically movable loading platform or loading fork assumes the upper position, the said supports with the corresponding guides are retracted into the passive position, whereby the retained crate or crates are unloaded onto the loading platform or loading fork below, which, as a result of each additional crate unloaded, is moved downwards by an amount corresponding to the thickness of the crate with the side walls folded down.

[0009] Of course, the device for removing the trays from the moving conveyor belt can be double-acting, so that the trays of a first model detected by the detection station for the model of the supplied trays in an upstream arrangement are moved towards one of the longitudinal sides of the conveyor belt, while the detected trays of a second model are moved towards the opposite longitudinal side of the same conveyor belt, thus allowing a reduction in the dimensions of the processing chain.

[0010] The damping element on which the pivoting stop plate can be of various known types, e.g. with a spring which is controlled by a piston, which is provided with a valve or nozzle for energy dissipation and acts inside a tight cylinder filled with gas or liquid.

[0011] The invention is explained in more detail with reference to a preferred embodiment of a high-efficiency machine according to the invention for sorting and stacking crates, which is schematically shown in the attached drawings; the drawings have a purely explanatory, non-limiting function.

[0012] The Fig. 1 is a perspective view of a machine for sorting and stacking crates with folded side walls, which is arranged on one side of a conveyor belt, in the area of ​​a device for conveying the supplied crates, recognized in advance with regard to the model and / or functionality, transversely to the movement of the conveyor belt.

[0013] The Fig. 2 shows the cross section according to the Fig. 3shown section plane II-II which extends through the guide and retaining mechanism, consisting of the horizontal retaining supports with the vertical, horizontally movable guides and the mechanism for dampening the impact of the crates moved transversely to the conveyor belt, in the direction of the sorting and stacking device.

[0014] The Fig. 3 shows the top view of the damping mechanism for the impact of the fed crates and the guide and retaining mechanism consisting of the horizontal retaining supports together with the horizontally movable vertical guides, of the machine according to the invention.

[0015] The Fig. 4 shows the cross section according to the Fig. 3 shown section plane IV-IV concerning the movement mechanism for the lateral horizontal retaining supports and the vertical guides.

[0016] The Fig. 5shows the front view of a guide fork which acts on a cylinder for the movement of the horizontal supports including vertical guides.

[0017] In a known, special detection station A, surveys are carried out on the trays 2 with folded side walls, which are fed in direction 2a by conveyor belts 3, using a camera 1 to determine the model of the tray 2. In a possible subsequent known station, further surveys can be carried out, e.g., to check the functionality of the trays; the ejection of any defective trays 2 or trays 2 that cannot be stacked by the subsequent stacking device C provided on both sides of the conveyor belt can be fed to an ejection station 2y.

[0018] Above the conveyor belt 2c there is at least one transverse displacement station B of known type which acts in one or both directions by means of a spatula 5, e.g. driven by a belt 5s, running on transverse guides 4c connected to the fixed frame 3. Downstream of said station B there is a retaining stop 3c which can pivot 3r about a horizontal axis 3i. This is controlled as a function of the elevations carried out in station A and is suitable for retaining the crates 2 to be stacked in the stacking device C on the moving conveyor belt 2c 2a. The models which cannot be stacked by means of the stacking device C, on the other hand, are not retained by the pivoting retaining stop 3c and are transported further 2y towards another retaining stop with a transverse displacement station and a specific stacking device.Of course, the pivoting stop 3c can be replaced by a retaining stop movable vertically in the direction of the conveyor belt 2c, and said stops can be equipped with known devices for cushioning the impact of the crates and preventing rebound. The crates 2 held back by the retaining stop 3c on the moving conveyor belt 2c are moved in a known manner in the transverse direction 5s by a spatula 5, which, for example, by a belt, runs on horizontal guides 4c, which are rigidly connected to a gate frame 3 connected to the frame of the conveyor belt or the stacking device C.

[0019] The stacking device C is provided laterally on the conveyor belt 2, in the area of ​​the transverse movement 2b of the crate 2 by means of a spatula 5; it essentially consists in the upper area where the crates 2 to be stacked are received, of a frame 1b with horizontally movable 2s retaining supports 2d with guides 2e and of a device 3d, 4, 4b for dampening the impact of the crates which are pushed 5s at high speed by the spatula 5 in the direction of the stacking device B, while in the lower area it essentially consists of known vertical holding guides 7 between which a vertically movable loading surface or loading fork 7d for the continuous stacking of the crates 2 fed by free vertical fall as a result of movement 2s of the horizontal retaining supports 2d from an extended active retaining position to a retracted rest position.

[0020] The damping device according to the invention consists of a stop plate 3d mounted in the lower region, pivotable about a horizontal axis 3s. This stop plate 3d rests on the rear, essentially in a vertical position, on a damping element or is connected to it, which consists of a hollow body made of elastic material, e.g. a plastic tube 4 with closed ends, and is provided with a possibly adjustable vent opening. The said tube 4 is fastened to a rigid element 4b which is connected to the frame 1b in the upper region of the device. The invention does not exclude the said tube 4 with vent opening being replaced by a known Damping deviceis replaced, e.g., by a spring with a piston provided with a valve or nozzle, which acts inside a sealed cylinder containing gas or liquid. The stop plate 3d can also be movable horizontally on guides provided on the frame 1b according to the invention. The dampening of the impact of the lateral edge of the tray 2, which is moved at high speed by the spatula 5, prevents the tray from rebounding and thus from reaching a position which could cause jamming during the free vertical fall downwards, or towards the horizontal retaining supports 2b in the retaining position.

[0021] In order to ensure a regular retention movement 2s for the horizontal retention supports 2d, together with the vertical guides 2e, or movement in the release position, even at very high work cycles, the invention proposes providing the cylinders 6 for the movement 2s with elastic cushions 6a and 6b, respectively, at their bases connected to the fixed structure and at the ends of the corresponding piston rods 6d. Furthermore, to prevent the action of the pneumatic or hydraulic piston pairs 6 on the same vertical guide 2e, or on the horizontal retention support 2d, from causing malfunctions due to the individual pistons not always operating synchronously, the invention provides for at least one of the cylinders 6 of each cylinder pair to be vertically guided by a fork 6c, which is connected to a fixed support 1e, whereby the front end of the cylinder 6, provided with corresponding vertical grooves, is retained in a vertically sliding manner.This guide by means of fork 6c prevents horizontal pivoting movements transverse to the axis of the same cylinder, whereby, despite the elastic cushions 6a, 6b, a regular movement 2s is always ensured free from jamming of the retaining pads 2d together with the guides 2e.

[0022] The system for dampening the impact of the crates 2 to be stacked, which are moved 5s at high speed transversely to the movement of the conveyor belt 2c by the spatula 5 towards the stacking device C, prevents the rebound of the crates and causes them to fall vertically, without jamming, between the vertical guides 2e to be held back by the horizontal supports 2d, or the regular depositing of the crates 2 on the loading surface or loading fork 7d provided below, which is vertically movable 7v for stacking, or on top of the stack of crates being formed, all with fast movement cycles of the said supports 2d together with the guides 2e.

Claims

1. A machine with high efficiency for sorting and stacking (C) crates (2) with foldable side walls, said machine consisting of at least one conveyor belt (2c), on which there is provided at the inlet end at least one detection station (A) for the purpose of recognizing the crate models fed in, and at least one restraining stop (3c) which is pivotable (3r) or acts vertically on the conveyor belt (2c), with a corresponding displacement station (B) for moving (5s) the crates (2) one way or back and forth transversely to the conveyor belt (2c), and with a corresponding stacking device (C), wherein the number of stacking devices (C) arranged on the conveyor belt (2c) corresponds to the number of different crate models that can be processed, wherein the stacking devices (C) are provided on one or both longitudinal sides of the conveyor belt (2c) in the region of the displacement station (B), characterized in that the upper part of each stacking device (C) comprises a rigid frame (1b) which has, on the side opposite that on which the crates (2) to be stacked and moving (2b) at high speed through the displacement station (B) are fed in, a stop plate (3d) which is mounted such as to be pivotable (3s) about a horizontal axis (3i) and which, in the vertical position, bears against or is connected to a damping element (4) held (4b) on the fixed frame (1b), and in that horizontal restraining supports (2d) are provided on both sides of the frame (1b), parallel to the feed direction (2b) of the crates (2) and transversely to the conveyor belt, said restraining supports (2d) being equipped with vertical guides (2e) which are movable between a retracted, inactive position outside of the free vertical passage of the crates (2) to be stacked and an extended, active intercepting and restraining position, the movement being effected by way of pneumatic or hydraulic, horizontally acting cylinder pairs (6), and in that the crates (2) in the stacking device (C) fall onto a vertically movable loading surface or loading fork (7d).

2. The crate stacking machine according to claim 1, characterized in that the damping element consists of a closed hollow body (4) made of elastic material, which has at least one, possibly adjustable, vent opening.

3. The crate stacking machine according to claim 1, characterized in that the damping element consists of a spring, which is controlled by a hydraulic, pneumatic or mechanical damper.

4. The crate stacking machine according to claims 1 and 2, characterized in that the stop plate (3d) is mounted on the fixed frame (1b) in such a way as to slide horizontally in the direction of the transverse movement (2b) of the crates (2) fed in (5s) by means of the displacement station (B).

5. The crate stacking machine according to claim 1, characterized in that a horizontal restraining support (2d) together with vertical guides (2e) is mounted on the same fixed frame (1b), on both sides of the stop plate (3d), parallel to the displacement movement (2b) of the crates (2) and transversely to the movement (2a) of the conveyor belt (2c), in such a way as to be horizontally movable (2s) by way of pneumatic or hydraulic cylinders (6) in order to define, in the extended position, by way of the lateral guides (2e), the position of the crates (2) at the inlet into the stacking shaft so as, in the extended position, to prevent the crates from dropping downward and, in the retracted position, to enable the crates (2) to drop vertically and to be deposited onto the vertically movable (7v) loading surface or loading fork (7d) located therebelow, or onto the stack of crates previously deposited on the loading surface or loading fork.

6. The crate stacking machine according to claim 1, characterized in that the cylinders (6), which are arranged in pairs and at a distance from each other, for the purpose of actuating (2s) each of the restraining supports (2d) together with the vertical guides (2e), are connected by the base of the cylinders, through the interposition of an elastic pad (6b), to a mount (1e) fastened to the fixed frame (1b), in that the ends of the piston rods (6d) of said cylinders (6) act on the horizontal restraining supports (2d) together with the vertical guides (2e) through the interposition of elastic pads (6a), and in that the adjustment movements of the cylinders (6), which are secured by the elastic pads (6a, 6b), are limited in the horizontal direction by a guide by way of forks (6c) which act in corresponding vertical grooves on at least one of the cylinders of the same pair, thereby enabling a vertical adjustment movement but preventing, for the same cylinder, horizontal adjustment movements transverse to the axis of the cylinder (6).