Dispensing – With casing or support – For bottom discharge dispenser supported on horizontal surface
Reexamination Certificate
2001-04-06
2002-10-01
Morris, Lesley D. (Department: 3754)
Dispensing
With casing or support
For bottom discharge dispenser supported on horizontal surface
C222S181100, C221S130000, C221S241000, C198S533000
Reexamination Certificate
active
06457610
ABSTRACT:
FIELD OF THE INVENTION
The present invention concerns a silo for the storage of lightweight hollow bodies, said silo being especially conceived (although its use can be generalized to also encompass other articles) to temporarily accumulate empty containers made of plastics material prior to ulteriorly feeding them to processing lines (filling, bottling, labelling lines, and so on), said silo being of the type that is provided with a charging inlet at a high level and at a lower region with an outlet provided to discharge the containers by gravity and arranged in a superimposed arrangement above an outfeed conveyor band connecting with a corresponding ulterior line provided for the processing or handling of said containers.
When inside a silo of big capacity (for example a right parallelepipedic enclosure with a side of 4 meters and a height of 5 meters) provided at the bottom with a discharge outlet the hollow, lightweight bodies of this kind, such as thin-walled containers made of plastics material, are highly prone to form “domes” or “bridges” that impede the regular and continued flow of said bodies through the corresponding discharge outlet. This is due to the fact that said bodies, for example containers, do frequently have irregular shapes and are provided with protuberances such as handles, necks, etc. causing (particularly under the conditions of random distribution and pressure of the other superimposed containers) said bodies to mutually interlock thus forming a sort of structure that is usually called a “dome” or “bridge”, said structure propping itself against the walls and thus causing a jam inside the silo thus preventing the containers involved and all those situated on top of them from descending by gravity towards the lower region of the silo.
Another limitation affecting the empty lightweight containers as regards their storage in silos of big dimensions resides in their relatively low crushing strength such as when sustaining collisions due to their free fall from an excessive height or when being submitted to the pressure exerted by the weight of a big quantity of containers piled up on top of a given container. This therefore limits the maximum height for a free fall from the upper charging inlet, as well as the maximum height for a piling up of containers inside the silo and on a bearing surface such as the bottom.
Another drawback of the above-mentioned silos, especially if they are provided for the storage of containers provided to be later on filled with liquids or beverages intended for human consumption, derives from the need to periodically clean the inside of the silo, said cleaning being a labour intensive job due to the big dimensions of these enclosures that are besides of difficult access (generally being only accessible through their top opening and through the use of lifting means or the like).
BACKGROUND OF THE INVENTION
In the prior art several devices have been proposed to solve the problem of delivering by gravity other solid, compact bulk materials such as mineral coal or gravel being prone to form domes.
Documents U.S. Pat. Nos. 2,905,365 and 3,286,886 thus disclose hoppers or devices for the delivery of bulk materials which are both formed by a bin with rigid, flat, fixed walls and with a rectangular cross-section whose surface area tapers from top to bottom, said bin being provided with an outlet at its lower end. Innerly attached to at least one of said walls is a rigid flat plate connected to means provided to impart a vibratory motion to said plate.
This arrangement has the drawback that between the rigid plate and the hopper's wall a gap is formed which tends to receive and accumulate dirt particles that hinder the operation of the device and whose removal without disassembling the unit involves a difficult cleaning operation. On the other hand, since the mechanisms provided to transmit the vibratory motion are arranged outside the hopper they must pass through the corresponding fixed wall of the latter in order to connect with the movable plate, this entailing a relative complexity of said mechanisms.
Document WO 95/03233 does moreover disclose a hopper for the delivery of bulk materials consisting in a bin of frustoconical shape whose cross-sectional surface area tapers from top to bottom, said bin being provided with an outlet at a lower end. The wall of said bin is formed by at least a rigid, fixed portion and at least a rigid, movable portion connected to means provided to generate a vibratory motion. This arrangement, although representing a certain simplification of the mechanisms as compared with those mentioned above, has the drawback that the element to be vibrated is at least a substantial portion of the main wall of the bin and has to be strong enough to withstand the pressure exerted by the material, said portion of said wall therefore having a relatively big mass and thus entailing a high energy consumption.
The devices described in the three above-mentioned documents are useful for the delivery of solid, compact bulk materials such as for example mineral coal, gravel, etc. which are not to be damaged by blows or as a result of being crushed. Such devices are nevertheless not apt to deliver in bulk lightweight hollow bodies such as containers made of plastics material, since these latter are liable to be crushed by the vibratory motion of the rigid plates or rigid portions of the bin in combination with the decreasing cross-sectional surface area of the latter, as well as by the weight of the very hollow bodies piled up on top of each other inside the silo, especially if this latter has a considerable height.
Also known in the art are devices such as deflector plates, nets with passage openings big enough for the containers, or labyrinths situated at different levels inside a tall silo, said devices being provided to limit the maximum height for a free fall of a container upon another one situated at a lower level, and the maximum height for the piling up of containers on top of a specific container in particular. Said deflector plates, nets or labyrinths are nevertheless a hindrance for the free flow of the stored articles, this then having to be added to the problem of the formation of “domes” or “bridges”.
Other technical background of interest regarding the object of the invention is to be found in patents U.S. Pat. No. 5,687,881 and WO-A-96/30727, EP-A-033 815, EP-A-001576, EP-A-0336815 and U.S. Pat. No. 4,127,970.
BRIEF DESCRIPTION OF THE INVENTION
The invention provides a silo of big capacity for the temporary storage of lightweight hollow bodies, said silo being provided to be emptied by gravity and being especially apt to accumulate said containers for example coming from a container production area prior to an ulterior delivery when the necessity arises to continuously feed empty plastic containers for example to bottling lines where said containers will be submitted to different processing operations (filling, capping, labelling, etc.). It thus becomes feasible to adapt the production of the machines forming said containers, for example injection moulders, to the needs of the bottling lines during the operational cycles of these latter.
According to a first object of this invention said silo is provided with means to adjust inclines delimiting the bottom of the silo or to jolt or vibrate said bottom in order to prevent the formation of “domes” or “bridges” or to disrupt them, as the case might be.
Another object of the invention consists in a dispensing device adapted to deliver empty plastic containers to a conveyor belt with a regular and controlled flow of said containers and with the possibility of an adaptation to the characteristics of size and shape of said containers.
Another object of this invention is that of providing a silo apt for the storage of lightweight hollow bodies, especially empty plastic bottles, the walls of said silo being easily washable since they can be “transferred” to the outside thus allowing to easily have access to all parts of their surface.
Yet another object of the
Morris Lesley D.
Nicolas Frederick C
Richardson & Folise
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