Palletizing head for containers, with vertically movable cam

Abstract

Palletizing head (1) for palletizing containers, comprising a roller curtain (2) having two rollers conveyors (21, 22) which can be guided by a frame ( 3) to increase an horizontal distance between them, a double door (23) horizontally located between the conveyor s (21, 22), and a vertically movable cam (4) to control the inclination of each door leaf (231; 232) with respect to a respective conveyor (21; 22) as a function of the horizontal distance.

Description

[0001]PALLETIZING HEAD FOR CONTAINERS, WITH VERTICALLY MOVABLE CAM TECHNICAL FIELD The present invention relates to a palletizing head for palletizing containers, with a roller curtain configuration, provided with a central door and a vertically movable cam for guiding the rotation of the door leaves. BACKGROUND ART In the field of packaging of pourable products by means of containers, it is known to use palletizing machines for palletizing the filled, closed, decorated, and possibly wrapped or packed containers. Commonly, the palletizing machine comprises a palletizing head which is configured for receiving sequentially the layers of containers, and for depositing each received layer on the pallet being formed. The palletizing head comprises two roller curtain sectors which can adopt a proximal position corresponding to a closed condition of the head, for receiving each layer of containers. The sectors can move horizontally with respect to each other to regulate an horizontal distance between the sectors, to define an opening degree of the head, for releasing each received layer of containers. The vertical movement of the containers may be not optimally guided, which can result in a too abrupt contact between the containers being deposited and the containers already deposited on the pallet. This may lead in a deterioration of the quality of the pallet being formed. DISCLOSURE OF INVENTION A palletizing head according to present description or according to any one of the appended head claims, is configured for providing an optimal control on the vertical movement of the containers being deposited, resulting in an improved accuracy of the palletization activity, an optimal cleanliness of the palletizing machine, an optimal versatility with respect to format of containers and of the pallet, without complicating the mechanical configuration of the machine. A palletizing machine according to present description or according to any of the appended machine claims comprises a head according to present description or according to any one of the appended head claims. The following brief description of the drawings and detailed description of the invention will be referred to a possible example embodiment of a palletizing head according to present description and a possible example embodiment of a palletizing machine according to present description. In the following brief description of the drawings and detailed description of the invention, the example embodiment of the palletizing head will be defined for the sake of convenience as “head”. In the following brief description of the drawings and detailed description of the invention, the example embodiment of the palletizing machine will be defined for the sake of convenience as “machine”. BRIEF DESCRIPTION OF THE DRAWINGS The following detailed description will be referred to the accompanying drawings, in which: Figure 1 is a partially sectioned side view, with parts removed for clarity, of the head, in a first instant during a method of use of the head; Figure 1A is a partially sectioned side view, with parts removed for clarity, of the head, in the first instant, from an opposite point of view with respect to Figure 1; Figure 2 is a partially sectioned side view, with parts removed for clarity, of the head, in a second instant during the method of use of the head; Figure 3 is a partially sectioned side view, with parts removed for clarity, of the head, in a third instant during the method of use of the head; Figure 4 is a partially sectioned side view, with parts removed for clarity, of the head, in a fourth instant during the method of use of the head; Figure 4A is a partially sectioned side view, with parts removed for clarity, of the head, in the fourth instant, from an opposite point of view with respect to Figure 4; Figure 5 is a partially sectioned side view, with parts removed for clarity, of the head, in a fifth instant during the method of use of the head; Figure 5A is a partially sectioned side view, with parts removed for clarity, of the head, in the fifth instant, from an opposite point of view with respect to Figure 5; Figure 6 is a partially sectioned side view, with parts removed for clarity, of the head, in a sixth instant during the method of use of the head; Figure 7 is a partially sectioned side view, with parts removed for clarity, of the head, in a seventh instant during the method of use of the head; Figure 8 is a partially sectioned side view, with parts removed for clarity, of the head, in an eighth instant during the method of use of the head; Figure 9 is a perspective view of the head; Figure 10 is a perspective view of a component of the head; Figure 11 is a schematic view for explaining some geometric quantities involved in the working of the head; Figure 12 is another schematic view for explaining some geometric quantities involved in the working of the head. DETAILED DESCRIPTION OF THE INVENTION The head 1 is configured for palletizing containers. The containers may be cans or bottles. The bottles may be glass bottles or plastic bottles. The containers to be palletized may be groups or layers of containers. Each group may be already wrapped or packed. The head comprises a roller curtain 2. The curtain 2 comprises a first roller conveyor 21 and second roller conveyor 22, which can adopt a proximal position between each other corresponding to a closed condition of the curtain 2. In said closed condition, the curtain 2 can receive a layer L2 of containers. In Figures 1-1A, 2-2A, 3, 8 and 9, the curtain 2 adopts the closed condition and the conveyors 21 and 22 adopt the proximal position. In Figures 1 and 1A, the curtain 2 is receiving a layer L2 of containers by means of the containers sliding on the roller conveyors 21 and 22. The layer L2 is to be received by the curtain 2 and is to be released or deposited on another layer L1 which has been already released and deposited on the pallet. Figure 11 is a schematization of the situation of Figures 1 and 1A. The conveyors 21 and 22 are configured for horizontally moving between each other to produce an increase of a horizontal distance D between them. The increase of said horizontal distance D corresponds to an increase of the opening degree of the curtain 2. The distance D is indicated in figures 11 and 12. In the proximal position, the horizontal distance between conveyors 21 and 22 is minimized. The increase of opening degree is for vertically releasing the received layer L2 on the pallet being formed, and therefore for example on a layer L1 which has been already deposited. When the curtain 2 is closed, the opening degree is zero. In Figures from 1 to 3, 8, and 9, the value of opening degree is zero, and therefore the curtain 2 is closed. The value of distance in the fourth instant of Figure 4 is bigger than the value of distance in Figures from 1 to 3. Therefore, the value of opening degree in the fourth instant of Figure 4 is bigger than the value of opening degree in Figures from 1 to 3. The value of distance in the fifth instant of Figure 5 is bigger than the value of distance in Figure 4. Therefore, the value of opening degree in the fifth instant of Figure 5 is bigger than the value of opening degree in Figure 4. The value of distance in the sixth instant of Figure 6 is bigger than the value of distance in Figure 5. Therefore, the value of opening degree in the sixth instant of Figure 6 is bigger than the value of opening degree in Figure 5. In Figure 8, the curtain adopts the closed condition again, after having released the layer L2. Figure 12 can be a schematization of each of Figures 4, 5 and 6, because the value of distance D in Figure 12 is bigger than the value of distance D in Figure 11. The head 1 comprises a frame 3 for guiding the horizontal movement of the conveyors 21 and 22 between each other. The frame 3 is vertically movable. In Figures 1, 2, 7 and 8, the frame 3 adopts an upper position. In Figures 3, 4, 5 and 6 the frame 3 adopts a lower position. The frame 3 can switch between the upper and lower position by means of the vertical movement of the frame 3. The frame 3 is vertically movable to be able to receive at a certain height the new layer L2 to be released, and to be able to move closer to the pallet in formation, and therefore for example to the already deposited layer L1, only afterwards. By means of a downwards vertical movement of the frame 3, the frame 3 moves from the upper position of the frame 3 to the lower position of the frame 3. By means of an upwards vertical movement of the frame 3, the frame 3 moves from the lower position of the frame 3 to the upper position of the frame 3. The curtain 2 comprises a door 23 which is horizontally located between the conveyors 21 and 22, in the sense that the height of the door 23 along he horizontal direction is between the height along the horizontal direction of the first conveyor 21 and the height along the horizontal direction of the second conveyor 22. The door 23 comprises a first leaf 231 hinged to the first conveyor 21 and a second leaf 232 hinged to the second conveyor 22. An inclination A may be generated by the gravity between each leaf 231 or 232 and the respective conveyor 21 or 22. The inclination is schematically shown in Figure 12. In Figure 11, the inclination is not indicated because the value of the inclination is zero in Figure 11. The head 1 comprises a cam 4 for supporting the leaves 231 and 232 of the door 23, to keep the door 23 closed in said closed condition of the curtain 2. The cam 4 is mounted on the frame 3 to be vertically movable with respect to the frame 3. In Figures 1, 2, 38, and 9, the cam 4 keeps the door 23 closed by supporting the leaves 231 and 232. The head 1 is configured, by means of the vertical movement of the cam 4 with respect to the frame 3, for correlating a variation of said horizontal distance D with a variation of said inclination A of each of the leaf 231 and 232 with respect to the respective conveyor 21 or 22. Each leaf 231 or 232 is hinged to a respective frontal edge 211 or 221 of the respective conveyor 21 or 22. The frontal edges 211 and 221 of conveyors 21 and 22 are faced towards each other. Each leaf 231 or 232 can in this way exert a guiding effect on the vertical motion of containers while the containers are being released by the curtain 2 by means of the increase of horizontal distance between the conveyors 21 and 22. Therefore the accuracy of the palletizing head 1 is increased. The cam 4 can therefore follow the vertical movement of the frame 3, and, at least when the frame 3 adopts the lower position, is also in turn vertically movable with respect to the same frame 3, to control the inclination A as a function of the vertical distance D. This results in a big flexibility of the palletizing head 1 with respect to type and format of containers. This also results in a very simple mechanical configuration because the system for guiding the inclination does not need to be integrated in the frame 3. There is also therefore a better cleanliness of the head 1. Moreover, the rotational motion of the leaves 231 and 232 may be quicker, thanks to the vertical movement of the cam 4 with respect to the frame 3, always in observance of the need of controlling and guiding said inclination. The need of controlling and guiding the inclination of the leaves 231 and 232 and therefore their rotational motion is correlated to the need of guiding the descending movement of the containers of the layer which is being released and deposited. The frame 3 comprises a wall 31. The head 1 comprises an actuator 5 for vertically moving the cam 4 with respect to the wall 31. The cam 4 and the actuator 5 are located on opposite sides of the wall 31. The cam 4 and the actuator 5 are connected to each other by means of a connection element 6 which is faced to a lower edge 31a of the wall 31. The connection element 6 is preferably a plate which is transversally arranged with respect to the wall 31. The plate 6 is indicated in Figure 9. The lower edge 31a is indicated in Figures 1 and 9. Point of views of Figures 1 and 1A are located on opposite sides of the wall 31, respectively. Point of views of Figure 4 and 4A are located on opposite sides of the wall 31, respectively. Point of views of Figure 5 and 5A are located on opposite sides of the wall 31, respectively. In this way, the cam 4 can move vertically to control and / or guide the inclination A of the leaves 231 and 232, by means of a moving assembly which is distributed on both sides of the wall 31 of the frame 3, to minimize the interference between the components configured for moving the cam 4 with respect to the frame 3 and the components configured for supporting and guiding the horizontal movement of the conveyors 21 and 22. Therefore a palletizing head 1 with increased flexibility by means of a very compact design is provided. By means of a downwards vertical movement with respect to the frame 3, the cam 4 is configured for interacting with the leaves 231 and 232 to guide an increase of said inclination A corresponding to said increase of said distance D, by means of mechanical contact. Alternatively or in addition, the cam 4 may guide the increase of inclination by means of magnetic or electromagnetic interaction. The downwards movement occurs from figure 3 to Figure 5. In Figures from 1 to 3, 8 and 9, the cam 4 adopts an upper position of the cam 4, while in figures 5, 6 and 7 the cam 4 adopts a lower position of the cam 4. In Figure 4 the cam 4 adopts a position located between the upper position and the lower position. By means of the downwards vertical movement of the cam 4 with respect to the frame 3, the cam 4 moves from the upper position of the cam 4 to the lower position of the cam 4. The horizontal distance between conveyors 21 and 22 is increasing from Figure 3 to Figure 6. The inclination between each leaf 231 or 232 and the respective conveyor 21 or 22 is increasing from Figure 3 to Figure 6. The increase of inclination from Figure 3 to Figure 5 is guided and / or controlled by the cam 4, by means of the downwards vertical movement of the cam 4 with respect to the frame 3. The increase of inclination from Figure 5 to figure 6 is not guided and not controlled by the cam 4. The increase of said inclination corresponds to an increase of the opening degree of said door 23 and a decrease of said inclination corresponds to a reduction of the opening degree of said door 23. At the minimum horizontal distance D between the conveyors 21 and 22, and therefore with the conveyors 21 and 22 in the proximal position, the cam 4 can close the door 23 by means of an upwards vertical movement with respect to the frame 3. By means of the upwards vertical movement of the cam 4 with respect to the frame 3, the cam 4 moves from the lower position of the cam 4 to the upper position of the cam 4. The upwards movement occurs from Figure 7 to Figure 8. In both figures 7 and 8, the conveyors 21 and 22 are at the minimum horizontal distance between them. In Figure 7, the frame 3 adopts the upper position of the frame 3 and the cam 4 adopts the lower position of the cam 4. In Figure 8, the frame 3 adopts the upper position of the frame 3 and the cam 4 adopts the upper position of the cam 4 to close the door 23 and keep the door 23 closed, so that the curtain 2 can be kept in the closed condition again, after the release of the last received layer of containers L2. The cam 4 is replaceable to adapt the palletizing head 1 to different needs and / or specific circumstances, for example to a change of format or type of containers. The head 1 is configured so that the vertical movement of the cam 4 and the horizontal movement of the conveyors 21 and 22 between each other are automatically timely coordinated between each other. In this way an optimal guiding effect on the inclination A of the leaves 231 and 232 can be obtained as a function of the horizontal distance D between the conveyors 21 and 22, and therefore also an optimal guiding effect on the vertical motion of containers. Each conveyor 21 or 22 lies horizontally to support the containers L2 to be palletized. Each of leaves 231 and 232 is provided with rollers 2311 for the sliding of the containers L2 to be palletized. The rollers 2311 are indicated in Figure 10. In this way the sliding of the containers on the curtain 2 is furtherly made easier. The head 1 comprises a respective stop 231a or 231b for each leaf 231 or 232, to limit the respective inclination A. From Figure 5 to Figure 6, the inclination A of each leaf of the door 23 is controlled by the respective stop 231a or 232a. Each stop 231a or 232a may be defined by a respective further cam guiding device, for controlling and limiting the inclination. In Figure 1, the curtain 2 is receiving the new layer L2 of containers to be palletized, and more specifically to be deposited on the already deposited layer L1 of containers. In Figure 2, the curtain 2 has received the new layer L2. In Figure 2, the downwards vertical movement of the frame 3 starts. In Figure 3, in which the frame 3 adopts the lower position of the frame 3, the curtain 2 is therefore closer to the already deposited layer L1. In Figure 3, the downwards vertical movement of the cam 4 starts. In Figures from 1 to 3, the conveyors 21 and 22 are at the minimum horizontal distance from each other, and therefore adopt the proximal position. From Figures 3 to 6, the horizontal distance D and the opening degree of the curtain 2 is increasing, to deposit the new layer L2. From Figure 3 to Figure 6, also the inclination of each of the door leaf 231 or 232 with respect to the respective conveyor 21 or 22 is increasing. The inclination is for guiding the descending motion of the new Layer L2. In Figure 7, the new layer L2 has been deposited, the frame 3 adopts again the upper position of the frame 3, and the horizontal distance between conveyors 21 and 22 is at the minimum value again. In Figure 7, the upwards vertical movement of the cam 4 from the lower position of the cam 4 to the upper position of the cam 4 starts, to close again the door 23. In Figure 8, the frame 3 adopts the upper position, the cam 4 adopts the upper position, the door 23 is closed, the conveyors 21 and 22 are at the minimum horizontal distance, and therefore the curtain 2 is stably closed again, ready to receive a further layer of containers. A palletizing head 1 for palletizing containers is provided, comprising a roller curtain 2 having two rollers conveyors 21 and 22 which can be guided by a frame 3 to increase an horizontal distance between them, a double door 23 horizontally located between the conveyors 21 and 22, and a vertically movable cam 4 to control the inclination of each door leaf 231 or 232 with respect to a respective conveyor 21 or 22 as a function of the horizontal distance. Each leaf 231 or 232 of the door 23 defines a flap which can be inclined with respect to the respective conveyor 21 or 22 for guiding the containers during the vertical descending motion of the containers by means of which the containers are deposited on the pallet being formed. The door 23 allows an improvement in the control of the vertical descending movement of the containers of the layer being deposited on the pallet. The inclination of the leaves of the door is controlled by the cam 4 without any complicated guiding system. In this way any problem of mechanical complexity is avoided, and the cleaning of the mechanical components of the head is very simple. Moreover, the head 1 can be adapted to different formats or types of containers, to have a specific control of the inclination of the leaves 231 and 232 of the door 23 for each specific format or type of container.

Claims

CLAIMS 1. Palletizing head (1) for palletizing containers, comprising: a roller curtain (2) comprising a first roller conveyor (21) and second roller conveyor (22), which can adopt a proximal position between each other corresponding to a closed condition of the curtain (2), for receiving a layer (L2) of containers, said conveyors (21, 22) being configured for horizontally moving between each other to produce an increase of an horizontal distance (D) between them, the increase of said horizontal distance (D) corresponding to an increase of the opening degree of the curtain (2), for vertically releasing the received layer (L2); a frame (3) for guiding the horizontal movement of the conveyors (21, 22) between each other; wherein the curtain (2) comprises a door (23) which is closed in said closed condition and which is horizontally located between the conveyors (21, 22), the door (23) comprising a first leaf (231) hinged to the first conveyor (21) and a second leaf (232) hinged to the second conveyor (22), so that an inclination (A) may be generated by the gravity between each leaf (231; 232) and the respective conveyor (21; 22); a cam (4) for supporting the leaves (231, 232) ofthe door (23), to keep the door (23) closed in said closed condition of the curtain (2), the cam (4) being mounted on the frame (3) to be vertically movable with respect to the frame (3); wherein the head (1) is configured, by means of the vertical movement of the cam (4) with respect to said frame (3), for correlating a variation of said horizontal distance (D) with a variation of said inclination (A) of each of the leaf (231; 232) with respect to the respective conveyor (21; 22).

2. Palletizing head (1) according to Claim 1, wherein each leaf (231; 232) is hinged to a frontal edge (211; 221) of the respective conveyor (21; 22), the frontal edges (211, 221) of conveyors (21, 22) being faced towards each other.

3. Palletizing head (1) according to Claim 1 or 2, wherein the frame (3) comprises a wall (31), and the head (1) comprises an actuator (5) for vertically moving the cam (4) with respect to the wall (31), the cam (4) and the actuator (5) being located on opposite sides of said wall (31) and being connected to each other by means of a connection element (6) which is faced to a lower edge (31a) of said wall (31), the connection element (6) being preferably a plate which is transversally arranged with respect the wall (31).

4. Palletizing head (1) according to any of the previous Claims, wherein said cam (4) is configured for guiding an increase of said inclination corresponding to said increase of said distance (D), by means of a downwards vertical movement of the cam (4) with respect to the frame (3), preferably by means of mechanical contact or magnetic or electromagnetic interaction between the cam (4) and the leaves (231, 232).

5. Palletizing head (1) according to any of the previous claims, wherein the increase of said inclination corresponds to an increase of the opening degree of said door (23) and a decrease of said inclination corresponds to a reduction of the opening degree of said door (23), so that, with the conveyors (21, 22) adopting the proximal position, the cam (4) closes the door (23) by means of an upwards vertical movement with respect to the frame (3).

6. Palletizing head (1) according to any of the previous claims, wherein said cam (4) is replaceable.

7. Palletizing head (1) according to any of the previous claims, configured so that the vertical movement of the cam (4) and the horizontal movement of the conveyors (21, 22) between each other are automatically timely coordinated between each other.

8. Palletizing head (1) according to any of the previous Claims, wherein each conveyor (21; 22) lieshorizontally to support the containers (L2) to be palletized.

9. Palletizing head (1) according to any of the previous Claims, wherein each of said leaves (231, 232) is provided with rollers (2311) for the sliding of the containers (L2) to be palletized. 10.Palletizing head (1) according to any of the previous Claims, comprising a respective stop (231a; 232a) for each leaf (231; 232), to limit the respective inclination (A).

11. Palletizing head (1) according to any of the previous Claims, wherein the frame (3) is vertically movable and the cam (4) is integral with the vertical movement of the frame (3).

12. Palletizing machine (1) for palletizing containers, comprising a palletizing head according to any of the previous Claims.

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