Device for the storage and feeding of products

A device for the accumulation and release of products disposed in ranks, comprises a storage unit with respective receiving and delivery openings for the products, a plurality of container elements movably guided within the storage unit between the receiving and delivery openings along a predetermined path, each container element being provided with a plurality of support surfaces for containing ranks of products, actuating means for controlling the movement of the container elements in the storage unit so as to present each container element to be filled in sequence at the receiving opening, for loading incoming ranks of products onto the respective support surfaces of the container and to conduct the previously filled containers to the delivery opening for the release of respective ranks of products leaving the storage units.

TECHNICAL FIELD

The present invention concerns a device for the accumulation and release of products disposed in ranks, in particular for feeding packaging lines for such products, according to the preamble of main claim No.1.

TECHNOLOGICAL BACKGROUND

Devices of the aforesaid type are widely used in packaging lines for confectionary products, such as chocolate bars, biscuits or others of similar type, in which such products are moved, on conveying lines, disposed in ranks or groups of ranks spaced from one another (by ranks there are meant in the present context rows of aligned products, in which the rows are disposed perpendicularly to the direction of advance of the products). Between these conveying lines and the packaging machines there is typically interposed a storage unit for the products to permit regular feeding at a predetermined and uniform rhythm of the packaging machine, and thus to render said feeding independent of the speed and variations in the flow of the incoming ranks.

With such storage units it is therefore possible to feed efficiently different automatic packaging lines having speeds and feeding rhythms programmed according to the type of product being dealt with.

Typically, such storage units comprise a magazine within which a plurality of container elements is supported and conducted in series along a path which optimizes the storage capacity. In general, the containers are regularly spaced from one another at a predetermined pitch and each comprises a plurality of shelves capable of supporting and containing respective ranks of products. The provision of one or more conveyor chains on which the containers are secured at a regular pitch is typical.

The slide path of the chain is further selected such that each container is conducted in sequence to the receiving opening for loading onto each of its shelves one or more ranks of products coming into the storage unit and, at the same time, a previously loaded container is conducted, by the effect of movement of the chain, to the delivery opening for the release of the products leaving the storage unit.

Storage units of this type normally extend in height and provide a vertical ascending section of the chain for loading the containers in sequence through the receiving opening and a descending vertical section of the chain for positioning the containers at the delivery opening and consequently unloading the products from the storage unit. These sections are part of the overall path, which may furthermore have a certain number of bends or returns having the function of maximizing the number of containers (and therefore of products) that can be accumulated within the storage unit.

A limit to be encountered in the known storage devices having the aforesaid characteristics lies in the fact that the distance between the last support shelf of one container and the first shelf of the container following it is generally different from the pitch existing between adjacent shelves of the same container. This makes it necessary to move the chain at different speeds in order to guarantee the same loading rhythm when passing from the last shelf of one container to the first shelf of the following container, both in the loading phase and in the phase of unloading of the products from the storage unit. This inequality of pitches produces accelerations and decelerations of the containers which may induce disturbing dynamic stresses in the movement of the containers themselves, for example inducing unwanted oscillating movements.

To these dynamic actions are further added unwanted swaying movements of the containers induced when passing through the winding sections of the path, which sections are produced by the bends of the chain created within the magazine to increase the storage capacity thereof. The rotational and translational movements induced by such curved paths may further compromise the alignment of the ranks of products supported in the containers. On the other hand, a limitation of such stresses and swaying movements is obtainable by reducing the speed of translation of the chain, thus requiring, however, much greater storage times for the loading of the magazine, to the detriment of the overall efficiency and productivity of the plant.

DESCRIPTION OF THE INVENTION

The problem underlying the present invention is that of providing a device for the accumulation and release of products disposed in ranks, which is structurally and functionally designed so as to make it possible to overcome the limits mentioned with reference to the prior art cited.

This problem is solved by the invention by means of a device for the accumulation and release of products which is produced according to the following claims.

PREFERRED WAY OF CARRYING OUT THE INVENTION

With reference to the figures mentioned, the reference1indicates as a whole a device for the accumulation and release of products P disposed in ranks, produced according to the present invention. The device is of the type comprising a storage unit2supported by a fixed structure, not shown in the drawings, and the body or outer containment casing3of which is shown diagrammatically by dashed lines in the views inFIGS. 1 and 3.

The storage unit2is provided with a receiving opening4through which are introduced the products P distributed in incoming ranks on a feed belt5, and with a delivery opening6for the release of the products P leaving the storage unit2.

The storage unit1further comprises a plurality of container elements7which are movably guided within the storage unit2, between the openings4and6, along a path8closed in a ring and defined by four respective rectilinear branches designated by8a,8b,8cand8d. More particularly, the path8has a rectangular configuration with the pairs of branches8a,8band8c,8dparallel and opposed to one another. The branches8aand8bconveniently extend vertically, meaning by the term “vertical” the direction perpendicular to the bearing surface at the base of the storage unit2, along which are respectively located the receiving opening4and the delivery opening6. On the other hand, the branches8c,8dextend in a “horizontal” direction, that is to say, parallel to the bearing surface of the storage unit.

Each container element7has a plurality of support surfaces, all indicated by9, rising one above the other and spaced from one another at a regular pitch and capable of receiving one or more incoming ranks of products from the belt5. Said container elements7are conducted in sequence along the path8(in a clockwise direction looking atFIG. 1) to bring each container7to be filled to the opening4, in order to load onto the surfaces9the ranks of products P fed by the belt5, and also to conduct the previously filled containers7to the delivery opening6for the release of the products P leaving the storage unit.

On the path8, the branch8ais the ascending branch for loading of the containers7, while the branch8bis the descending branch for unloading the containers. The branch8cis the branch for storing the containers7, along which the latter are held in position one against the other, as will appear clearly hereinafter. The branch8dis the branch for transferring the containers7, already unloaded along the branch8b, and for storing them while waiting to be loaded again along the ascending branch8a.

Along the branches of the path8means are also provided for actuating the containers7. It should be noted that the actuating means active along the branches8aand8bare structurally and functionally similar to one another and the description will therefore be limited to the ascending branch8a, it being intended that corresponding actuating means are provided for the descending branch8band, where appropriate, details common to the two aforesaid branches being designated by the same numerical references. Equally, actuating means structurally and functionally similar to one another are provided along the storage branches8cand8d, and therefore the description will be limited with reference only to the storage branch8c, details common to these two branches of the path being designated, where appropriate, by the same numerical references.

The actuating means arranged for the movement of the containers7along the branch8acomprise first and second separate control means10,11, respectively associated in sequence with one or another container7, disposed in succession to one another, of each pair of containers that can be observed in the storage unit2. In other words, containers7consecutive to one another along the path, which engage the branch8a, are actuated in sequence, respectively by the actuating means10and11, such, that both of said containers7are conducted from and towards the receiving opening4with independent movements with respect to one another. The first control means10comprise two pairs of motor-driven chains11a,11band11c,11d, wound on respective drive12and return13sprockets and also extending with their operative branches parallel to the ascending branch8a. The reference14indicates a servomotor capable of driving in synchronization the drive sprockets of the chains11a,11band, by means of a return15, the drive sprockets of the opposed pair of chains11c,11d. Each pair of chains is further provided with respective coupling means, indicated as a whole by16, capable of engaging respective complementary coupling means17provided on the opposed sides of the containers7for raising same along the ascending branch8aof the storage unit2. Said coupling means16comprise respective plate-like members18, secured, at a regular pitch, to each pair of chains11a,11band11c,11d, from which there are raised in the same direction and transversely, support rollers19capable of interfering with portions of respective wings20protruding from the opposed sides of the containers, as shown inFIGS. 5 and 8.

The actuating means11in their turn comprise two pairs of motor-driven chains21a,21band21c,21dwound on respective drive22and return23sprockets and also extending with their operative branches parallel to the ascending branch8a. The reference24indicates a servomotor capable of controlling in synchronization the drive sprockets of the chains21a,21band, by way of a return25, the drive sprockets of the opposed pair of chains21c,21d. Each of said pairs of chains is further provided with respective coupling means, indicated as a whole by26, structurally identical to the coupling means16, which are capable of engaging the complementary coupling means17provided on the opposed sides of the containers7for raising same, along the ascending branch8a. The coupling means26are secured to the chains21a–21dat a regular pitch, conveniently equal to that provided for the coupling means16.

It will be noted, with particular reference toFIG. 5, that on the one hand the chains11a,11b,21a,21band, on the other hand the chains11c,11d,21c,21dhave return axes coaxial with one another with the operative branches of each of the pairs of chains parallel and mutually spaced.

The actuating means provided along the descending branch8bcomprise first and second separate control means, these also, for the sake of simplicity, indicated by10,11, in their turn including respectively two pairs of chains31a,31b,31c,31dand41a,41b,41c,41d, having the same structure as the chains associated with the ascending branch8a, to the description of which reference should be made for any further detail. In this case also, containers7consecutive to one another, which engage the branch8b, are moved from and towards the delivery opening6with independent movements with respect to one another. For the movement of the containers along the storage branch8c, first conveying means are provided, indicated as a whole by42, and capable of conducting the containers7(filled with products P) one after the other in a collected position and one against the other. Said means42comprise pairs of motor-driven chains43wound on respective drive44and return45sprockets, and having their operative branches elongated horizontally along the branch8c. More particularly, pairs of double motor-driven chains are provided, bearing idle rollers46pivoted on pins47constituting pins of two single chains side by side and firmly secured to each other (FIG. 7). The rollers46are mounted so as to be idle, and support the wings20of the containers7, at a groove48provided at the bottom on the wings themselves. The chains43in their turn are supported and slidably guided on guide profiles48aextending parallel to the branch8cand connected to the fixed structure of the storage unit2. In the movement of the chains43, each container7is moved jointly with the latter along the branch8c, owing to the friction developed in the bearing contact of the wings20on the respective idle rollers46. Arresting means, indicated by49, are provided at the arrival end of the branch8cand are capable of interfering with the container7to retain it (together with the remaining containers pushed against it) in one direction in the end position reached, independently of the movement of the chains, owing to the creep and/or relative rolling between the idle rollers and the wings of the containers. The accumulation of the containers7and their retention is therefore ensured by the arresting means49during the continuous movement of the chains43.

For the movement of the containers7along the lower transfer branch8d, second conveying means are provided, indicated as a whole by50, having a structure substantially identical to the conveying means42. These also include pairs of double motor-driven chains43with idle support rollers46for supporting the containers7, for details of which reference should be made to the description provided previously with reference to the branch8c, co-operating with arresting means49ain a manner entirely similar to those provided in the branch8c.

The reference51designates thrust means arranged for transferring each of the containers7, in the passage along the path8, from the ascending branch8ato the storage branch8cand from the latter to the descending branch8b. Said thrust means51are produced for example by means of one or more thrust members52firmly secured to the movement of a chain53and capable of interfering with the container7to move same from one branch to the other at the confluence of said branches along the path8.

The reference54indicates a thrust member capable of displacing the ranks of products P from each support surface9to an outlet belt55, in the phase of unloading of the containers7and release of the products leaving the storage unit2.

For greater understanding of the operation of the device described hereinafter, the container members illustrated inFIGS. 1 and 3are designated individually by the numerical references7a,7b,7c,7d,7e,7f,7g,7h,7i,7land7m, so as to facilitate detection of the position thereof within the storage unit.

In an initial reference phase of operation, illustrated inFIG. 1, the container7ais positioned at the receiving opening4, with the belt5in alignment with the top support surface9of the container7afor the transfer of a rank of products P onto said surface. The container7ais raised by the control means10, by means of coupling with the chains11a–11d. A sensor57is provided to detect the passage of the rank and to operate the servomotor14in order to displace the container7aby a pitch (equal to the distance between consecutive surfaces9) so as to complete the loading of all the support surfaces9with respective ranks of products P.

In this phase the container7bis uncoupled from the storage branch8dand is positioned below the container7a. The containers7c,7d,7eare retained in a position one against the other on the branch8cby the arresting means49a. The container7m, after filling has taken place, is raised until it is aligned with the conveyor chain43for its transfer along the branch8cby the thrust means50. The full containers7l,7i,7hare stored on the branch8c, retained by the arresting means49. The container7gis displaced by the chains31a–31d(by means of mutual engagement of the respective coupling and complementary coupling means16,17) by an intermittent movement to the delivery opening6along the descending branch8bto allow the unloading of the ranks of products P from the respective support surfaces9. The container7fis coupled to the chains41a–41dafter the unloading of the products onto the belt55has taken place and Is displaced in a continuous motion in the direction of the storage branch8dfor empty containers.

In a following phase of operation of the device1, illustrated inFIG. 3, the container7a, raised by the control means10, is at the end of the filling phase with the last support surface9(that at the bottom level) aligned with the belt5for loading into the container7athe last rank of products P. In this phase the container7bis moved closer to the container7aby means of the respective separate control means11until it reaches a position in which the distance between the last surface9of the container7aand the top surface of the container7bis equal to the pitch existing between consecutive surfaces9of the containers. In this way the ranks of products can be introduced into the containers at an always constant pitch at a uniform rhythm also during the passage from one container to the next.FIG. 4shows the lined up state of the containers7a,7b.

In this phase, in addition, the containers7c,7d,7eare held stored on the branch8dby actuation of the arresting means49a. The container7f, previously emptied, is in transit along the branch8duntil it reaches the position pushed against the container7e. The container7m, transferred onto the branch8c, is moved along this storage branch. The container7his transferred by the thrust means51onto the descending branch8band is controlled by the chains41a–41dwhile approaching the container7g. Owing to the control movements, independent of one another, of the containers7gand7h, the distance between the top surface9of the container7gand the last lower surface of the container7hmay be made equal to the pitch existing between the surfaces9of the same container, so as to ensure release of the ranks of products at a constant pitch in a uniform rhythm also during the passage from one container to the next.

The phases illustrated inFIGS. 1 and 3are then repeated cyclically in order to obtain in sequence the loading of each container along the ascending branch8aand the emptying of corresponding containers along the descending branch8d.

It is understood that the number of containers provided in the storage device may vary according to specific requirements. It should be noted that the storage capacity is substantially linked to the number and to the dimensions of the containers that can be pushed one against one the other along the storage branch8c, and the storage volume can therefore be increased for example by elongating the storage unit horizontally and/or increasing the number of support surfaces of each container. The ascending and descending branches of the storage device, which define the overall vertical dimension thereof, serve substantially to ensure the filling and emptying of at least a pair of containers consecutive to each other, by means of movements independent of one another. In this way the phases of filling and emptying of the containers are rendered substantially independent of the movement of the remainder of the containers within the storage unit.

The invention thus solves the problem posed while providing numerous advantages with respect to the known solutions.

A principal advantage lies in the fact that in the device according to the invention it is possible to maintain, both in the filling phase and in the emptying phase, a distance between the last support surface of one container and the first surface of the container adjacent thereto which is equal to the pitch of the support surfaces. This equality of pitches permits movement of the containers at constant speed in the loading/unloading phases without inducing acceleration/deceleration of the containers themselves, responsible for any unwanted swaying motions.

Another advantage is due to the fact that in the ascending and descending branches the containers are controlled individually with movements independent of one another. Since the full container can in fact be moved away at a speed different from that consecutive thereto in the filling phase, the efficiency and productivity of the device are increased.

Another advantage is that the container is not bound, as in the known systems, to a fixed chain pitch, which pitch constrains the entire movement of the series of containers. According to the invention, the container filled on the ascending branch at a certain displacement speed, may directly follow the path towards the storage and emptying side at a different (and higher) speed and at a pitch different from the container which precedes it. This advantage is also reflected in the phase of emptying of the containers.

Yet another advantage is that the movement necessary for passing from one container to the next during filling, in contrast to the known systems, does not limit the running speed. In the known solutions, in fact, the entire series of containers is moved along the path defined in the storage unit with a need for considerable power for moving the entire train of containers. According to the invention, the branches for filling and emptying of the containers are actuated independently of the branches for storage of the containers, with consequently less power required and the possibility of using different displacement speeds in order to optimize the storage and release times for products in the storage unit.

Moreover, in the device of the invention, the provision of rectilinear branches in the loading/unloading and storage paths makes it possible to eliminate unwanted oscillating and swaying movements of the containers which, on the other hand, are generated in the known systems, especially in the presence of returns and bends in the paths described within the storage units.

Another advantage is that the containers of the device according to the invention are not rigidly secured to the conveyor chains, with consequent ease of replacement and/or removal for maintenance operations (for example in the washing operations).

Yet another advantage is that the device according to the invention makes it possible to obtain a reduced travel for each container from the filling point to the emptying point, without the need for a complete revolution of travel of the chain, as provided in the known systems.