OBJECT TRANSFER DEVICE FOR ROLLER CONVEYOR

Abstract

A device for transferring objects (1) from a roller conveyor (2) of the type comprising a clamped frame to a drag chain (4), the device being characterized in that it comprises: - a plurality of rollers (2) configured to move, following a forward direction, driven by the drag chain (4) and, at the same time, rotate about a central axis (5); - articulation elements (6), attached to one end of the central axis (5) of each roller (2), such that they allow the roller (2) to tilt about said articulation element (6), the articulation element (6) being attached / linked to the frame; - steering elements (7) attached to the other end of the central axis (5) of each roller (2) and linked to a guide (8) along which they move; - a guide (8) having an increasing inclination, in a longitudinal direction of the guide, from a first end of the guide (8') to a second end of the guide (8'') in the direction of advance of the drive belt (4); such that, as the rollers (2) advance on the drive chain (4), the configuration and orientation of the guide (8) force a change of trajectory of the guiding elements (7) that causes the rollers (2) to tilt around the joint (6), causing the transfer of the objects (1) arranged on them in a synchronized manner to a second cup-type conveyor (3) for subsequent weighing and distribution; and the guide (8) has an orientation, in its longitudinal direction, with a certain angular deviation with respect to the direction of advance of the drive chain (4).

Description

OBJECT TRANSFER DEVICE FOR CONVEYOR ROLLERS OBJECT OF THE INVENTION The object of the invention is a system for transferring objects from a roller conveyor, also known as a yoyo or diavolo type conveyor, to another type of conveyor in a unitary and synchronized manner. BACKGROUND OF THE INVENTION The use of roller conveyors is widespread, and their application is particularly relevant for objects with spherical or ellipsoidal shapes (imperfect spheres). This is why their use is especially prevalent in the agri-food sector for transporting "spherical" fruits. Yoyo conveyors are those consisting of at least two parts, which can be motorized, typically by contact with a lower surface, allowing the object placed on the conveyor to rotate. They allow objects to be moved and rotated simultaneously. For this reason, they are widely used in sections where, at the same time as transport, visual inspection (usually using machine vision systems) of the objects is carried out to verify some of their external (aesthetic) characteristics. It is important to note that these types of conveyors are complex (for example, compared to standard conveyor belts) and are therefore only used in areas where operations will be performed simultaneously with the movement of objects. Thus, these conveyors are often used, for example, in conjunction with visual inspection tools using machine vision. When transferring objects from a roller conveyor to other types of conveyors, several devices are known, such as the one described in document ES2441228T3. This document proposes a roller conveyor mounted on a transport shaft by means of a hinge. When the system detects that the object being transported needs to be transferred, this hinge releases the object, allowing it to fall by gravity or other means to an inclined position. This inclined position facilitates the object's deposition at a storage point located on the side of the roller conveyor. Another example that follows a similar principle is ES2939390A1, which employs a transport module comprising a concave assembly that holds the fruit. Openings along the lower edge of this assembly allow for the projection of conical elements that come into contact with the transported object and rotate it. Furthermore, the transport module is articulated so that when it detects that the object on the conveyor needs to be transferred, it tips it to one side onto another conveyor or to a corresponding storage point. Another system used for a very similar purpose is described in document ES2180973T3, which employs a gripper conveyor that individually picks up each object from the roller conveyor and transfers it to a hopper in a synchronized manner. This is an extremely complex system that can cause the object to be crushed and / or fall if it is soft (ripe fruit). The previous proposals (except the last one) do not guarantee the free rotation of objects of different sizes and shapes. Since these rollers incorporate the individual weighing and ejection mechanism, these can interfere with the rotation, especially with smaller objects, and therefore do not guarantee free and uniform rotation for sequential image capture. The last proposal is extremely expensive, requires more space for object transfer, and carries the risk of the object falling (being lost). DESCRIPTION OF THE INVENTION BY MEANS OF A PREFERRED EMBODIMENT To solve the technical problems mentioned in the previous section, a technical solution has been developed that greatly simplifies the transfer of objects from a roller-type conveyor (yoyo or diavolo type conveyor) to another individual conveyor, preferably of the cup type, for subsequent weighing and distribution. This is a transfer device specially designed to transfer ellipsoidal (or spherical) objects from a roller conveyor (yoyo type conveyor) to a different type of conveyor, such as a cup conveyor, where weighing the object is simpler and production capacity (speed) is increased. The system in which the device is installed comprises a roller conveyor equipped with a main transport element that moves the rollers in a forward direction, while these rollers rotate around a central axis (corresponding to each roller). The system comprises at least one transfer zone, in which the device of the invention is located, and preferably includes a pre-inspection zone where objects can be selected according to pre-established criteria. In the case of fruit, this selection can be based on size, possible aesthetic defects in the skin, or other surface characteristics, etc. In this machine vision inspection zone, there can be at least one camera. This eliminates the need for weighing and ejection mechanisms in the transfer device. This improves the rotation of objects on the rollers, especially if they are not perfectly spherical. This is particularly important when transporting items such as fruits with stems and leaves, as it prevents the leaves from becoming trapped in the weighing and / or ejection mechanisms. Thus, preferably, in the inspection zone the relevant characteristics being evaluated of each object are determined and, subsequently, the objects arrive at the transfer zone. In the transfer zone is the transfer device, which comprises a guide and steering elements (linked to the rollers on which the objects move). These elements, working together, allow the rollers' trajectory (orientation and / or direction) to be modified, forcing them to tilt on a hinge. This tilting action causes the objects to be transferred to the corresponding storage point or another type of conveyor. In other words, the roller's axis is initially horizontal and tilts relative to the horizontal to tilt the object. Therefore, when the transfer device is used in a fruit transport and transfer system, the fruit is first sorted in an inspection zone, where, for example, the diameter and / or skin defects are determined using computer systems. Subsequently, in a transfer zone where the device is located, the fruit is moved laterally. This lateral movement is achieved by tilting the rollers of the roller conveyor, a process forced by the elements of the transfer device, and more specifically by the interaction of the guide and the steering elements (cams). The steering elements move along the guide, which has an increasing inclination, and are oriented longitudinally at a specific angular deviation relative to the direction of travel of the drive chain.Thus, as the guiding elements move along the guide, their height relative to the drive chain increases and their orientation changes. Since the articulation elements always remain in the same relative position with respect to the drive chain, the rollers pivot on the point where they are attached, via their central axis, to the articulation elements, causing the objects to be ejected laterally. When the fruit is to be transferred from a roller conveyor to a bucket conveyor, these are linearly synchronized by mechanical or electrical means controlled by the system. The present invention allows the transfer of objects from a roller conveyor to a cup conveyor in a very simple way, much simpler than other known prior art systems used for the same purpose. BRIEF DESCRIPTION OF THE FIGURES To complete the description and to aid in a better understanding of the characteristics of the invention, a set of drawings is included with this descriptive document as an integral part thereof, in which, for illustrative and non-limiting purposes, the following has been represented: Figure 1 represents an overview of a transport and transfer system with an inspection zone and a transfer zone in which the transfer device of the invention is located. Figure 2 shows a detail of the transfer device of the invention in which the guide configuration and the interaction between the guide and the steering elements that determine the position of the rollers can be seen. Figures 3A-D represent details of the different points A, B, C, D of the transfer zone indicated in Figure 1, to show how the relative position of the rollers varies with respect to the main transport element as the steering elements (cams) advance along the guide. Figures 4A-C represent a roller in different positions relative to the drive chain to show how the roller pivots on the joint that is always kept in the same relative position with respect to the drive chain. Figure 5 represents an elevation view of the roller conveyor and the device, showing how the position of the rollers varies along the path. The following is a list of the various elements represented in the figures that comprise the invention: 1: object; 2: rollers; 3: cups; 4: drive chain; 5: central shaft; 6: articulation element; 7: steering element; 8: guide; 8: first end of the guide; 8: second end of the guide; 9: transfer zone; 10: inspection zone; 11: camera DESCRIPTION OF THE PREFERRED REALIZATION As can be seen in Figure 1, the device of the present invention is an object transfer device (1) from a roller conveyor (2). In the embodiment shown in Figure 1, the objects (1) are transferred from the roller conveyor (2) to a cup conveyor (3) in a synchronized manner. The roller conveyor (2) is of the type comprising an individual frame clamped to a drive chain (4). The device comprises a plurality of rollers (2) configured to move, following a forward direction, driven by the drive chain of the roller conveyor and, at the same time, rotate around a central axis (5). Likewise, the device comprises articulation elements (6), attached to one end of the central axis (4) of each roller (2), such that they allow the roller (2) to tilt on said articulation element (6). Also forming part of the device of the invention are steering elements (7) attached to the other end of the central shaft (4) of each roller (2) and linked to a guide (8) along which they move. The guide (8) of the device has an increasing inclination, in a longitudinal direction along the guide, from a first end of the guide (8) to a second end of the guide (8) in the direction of travel of the drive chain (4). Thus, as the rollers (2) advance along the drive chain (4), the configuration and orientation of the guide (8) force a change in the trajectory of the steering elements (7), causing the rollers (2) to tilt around the joint (6), thereby transferring the objects (1) placed upon them. Preferably, the guide (8) is of the trampoline type. Preferably, in addition, the guide (8) has an orientation, in its longitudinal direction, with a certain angular deviation with respect to the direction of advance of the drag chain (4). When the rollers (2) are in the transport position, the central axis (5) around which they rotate is arranged in a plane parallel to a plane in which the drag chain (4) is located and extends in a direction transverse to the direction of travel of said drag chain (4). As can be seen in figure 3, as the guiding elements (7) move along the guide (8) to perform the transfer of the objects (1), the orientation of the central axis (5) changes. More specifically, as the steering elements (7) increase their height relative to the drag chain (4), due to the increasing inclination of the guide (8), it can be seen how the central axes (5) of the rollers (2) go from being in a plane parallel to the plane in which the drag chain (4) moves and become inclined, with respect to said plane, pivoting on the point where the articulation element (6) is located. Likewise, as the steering elements (7) change their forward orientation, following the orientation of the guide (8), i.e., modifying their angular deviation with respect to the forward direction of the drag chain (4), contributing to the pivot of the rollers (2). As shown in Figure 1, the device is intended for installation in a transfer zone (9) of a transport and transfer system. Preferably, prior to this zone, there is an inspection zone (10) where a visual inspection of the objects (1) to be transported is carried out to select them based on predefined criteria. For example, when the invention is used in the agri-food sector, the objects (1) may be fruits that undergo a visual inspection in the inspection zone (10) to determine if any have surface defects. Subsequently, in the transfer zone (9), each fruit (object (1)) is transferred to a container (3) for later distribution according to size, skin defects, or weight. The roller elements (2) may have a biconical configuration to facilitate the reception of the objects (1) to be transported. These roller elements (2) are arranged one after the other and are supported by the drag chain (4). As can be seen in Figure 2, the guiding elements (7) act as cams. Preferably, these guiding elements (7) are cams made of plastic material. The geometry of the guide (8), with its increasing inclination, and its oblique orientation with respect to the direction of travel of the drag chain (4), cause the rollers (2) of the roller conveyor to tilt towards the opposite side of the guide (8) as it advances through the transfer zone (9), ultimately tipping the transported objects (1) onto the second conveyor line or the storage point. In a preferred embodiment of the invention, the second conveyor is a cup conveyor and comprises a plurality of cups (3) configured to receive and hold the objects, preferably one object in each cup in a synchronized manner. This second conveyor is also shown in the figures. In one embodiment, the system in which the device is installed further comprises a machine vision system with at least one camera (11) in the inspection area (10). As previously described, this type of system is of particular interest when used to transport spherical / ellipsoidal-shaped fruit. In these cases, the inspection zone (10) is used to check, for example, for rot in the fruit being analyzed. This is achieved by inspecting the entire surface because, due to the rotation of the roller elements (2), the objects (1) (in this case, the fruit) rotate as they move along the roller conveyor (rotary conveyor). If, during this visual inspection, a piece of fruit is determined to be in an "unacceptable" condition, its position is recorded. When the fruit is subsequently transferred from the rotary conveyor to the cup conveyor, the "unacceptable" piece is discarded. The means for discarding the fruit pieces on the cup conveyor are outside the scope of this invention. Figures 3A-D show details corresponding to points AD marked in Figure 1, illustrating the position of each element of the device relative to the system's drive chain (4). The position of the objects (1) on the rollers (2) is also shown. As can be seen, points AD were chosen to demonstrate the sequential movement of the different elements as they travel in the forward direction. Figures 4A-C show the movement of a roller (2), shown in isolation to more clearly illustrate the tilting motion. In Figure 4A, the roller (2) is in a position where the central axis (5) is parallel to the drive chain (4). As can be seen, in this position, the steering element (7) is transverse to both the central axis (5) and the drive chain (4). Figure 4B shows how the roller (2) has tilted, so that the steering element (7), which is perpendicular to the central axis (5), is no longer perpendicular to the drive chain (4). The central axis (5) is now tilted relative to the drive chain (5) because it has tilted around the articulation element (6). Figure 4C shows the same position as Figure 4B from a different perspective.Thus, as can be seen in figures 4A-C, the rollers (2) are free of mechanisms in their radial part, which is an advantage over currently known solutions. Figure 5 shows an elevation view of the roller conveyor and the device of the invention, in which the inclination and orientation of the guide (8) can be seen, and how the steering elements (7), when advancing in the longitudinal direction of the guide, force the rollers (2) to pivot on the joint (6). Thus, the proposed device presents multiple and notable advantages over current state-of-the-art systems, providing a simple and compact solution for transferring objects from a roller conveyor to other types of conveyors (such as cup conveyors) or to storage points.

Claims

1. A device for transferring objects (1) from a roller conveyor (2) of the type comprising a clamped frame to a drag chain (4), the device being characterized in that it comprises: - a plurality of rollers (2) configured to move, following a forward direction, driven by the drag chain (4) and, at the same time, rotate about a central axis (5); - articulation elements (6), attached to one end of the central axis (5) of each roller (2), such that they allow the roller (2) to tilt about said articulation element (6), the articulation element (6) being attached / linked to the frame; - steering elements (7) attached to the other end of the central axis (5) of each roller (2) and linked to a guide (8) along which they move;- a guide (8) having an increasing inclination, in a longitudinal direction of the guide, from a first end of the guide (8') to a second end of the guide (8'') in the direction of advance of the drag belt (4); so that, as the rollers (2) advance on the drag chain (4), the configuration and orientation of the guide (8) force a change of trajectory of the steering elements (7) which causes the rollers (2) to tilt around the joint (6), causing the transfer of the objects (1) that are arranged on them in a synchronized manner to a second cup-type conveyor (3) for further weighing and distribution;and the guide (8) has an orientation, in its longitudinal direction, with a certain angular deviation with respect to the direction of travel of the drive chain (4).

2. Device according to any one of the preceding claims, wherein the guiding elements (7) are cams that slide on the guide (8), which is of the trampoline type.

3. Device according to any one of the preceding claims, wherein the guiding elements (7) are cams made of plastic material.