US20060081447A1

US20060081447A1 - Guide particularly for conveyor belts

Info

Publication number: US20060081447A1
Application number: US11/000,965
Authority: US
Inventors: Sergio Fandella
Original assignee: Plastomeccanica SpA
Current assignee: Plastomeccanica SpA
Priority date: 2004-10-18
Filing date: 2004-12-02
Publication date: 2006-04-20
Also published as: EP1647505B1; EP1647505A2; US7121400B2; DK1647505T3; DE602005018145D1; US20060081448A1; EP1647505A3; ATE451315T1; ITTV20040115A1

Abstract

A guide, particularly for conveyor belts, inside which it is possible to accommodate first elements for generating a magnetic field, each one being constituted by a single permanent magnet, which has a U-shaped cross-section and has at least one pair of wings that protrude upward; the magnet can be inserted within a complementarily shaped receptacle formed inside the guide structure that can support slidingly a chain composed of a plurality of conveyance elements, which have second elements for their mutual engagement and are made at least partially of ferromagnetic material.

Description

The present invention relates to a guide particularly for conveyor belts.

BACKGROUND OF THE INVENTION

The design of suitable systems for moving semifinished articles from one processing station to the next and for moving the finished products toward the store is particularly important in the provision of industrial facilities for manufacturing or processing goods of various kinds.
Especially in the case of facilities that have a high production capacity, these movement systems must be completely automated and must ensure high efficiency and reliability, since the malfunction of one of them may halt the entire production facility or part thereof.
Moreover, the need to limit the overall space occupation of processing facilities, while on the one hand reduces the average distance that a semifinished or finished product must cover before reaching the next processing station or the store, on the other hand forces said products to trace convoluted paths, which often have curves that have the most disparate radii of curvature.
A first known type of conveyor belt is currently used to move semifinished or finished products within an industrial production facility and is constituted by a guide on which a chain slides, said chain being composed of a plurality of conveyance elements, which are mutually connected so that they can rotate with respect to each other on the plane of travel of said chain.
Thanks to this rotary connection among the individual conveyance elements, it is possible to provide conveyor belts that have curved portions.
The main drawback of this first known type of conveyor belt is that, due to the forces mutually transmitted among the individual conveyance elements, said elements tend to rise, at any bends of the guide, on the outer side of said bend.
A second known type of conveyor belt is used as a partial solution to this drawback; said second type is composed of conveyance elements provided with an upper loading surface, from which first inclined abutment surfaces protrude downward and abut, at the curved portions of the guide, against complementarily shaped second abutment surfaces, formed on said guide, which prevent the chain from rising.
The main drawback of this second known type of conveyor belt is that it is necessary to provide the first abutment surfaces on all the conveyance elements of the chain and on the guide, causing an increase in the manufacturing costs of the conveyor belt.
Another drawback of this second known type of conveyor belt is that the first and second abutment surfaces are subject to intense wear.
Another drawback is that fragments or portions of the conveyed products, such as for example glass splinters or metallic elements, may accidentally jam between the abutment surfaces, causing an increase in wear or even halting the belt.
Moreover, a third type of conveyor belt is known which has means for generating a magnetic field that is capable of attracting toward the guide the conveyance elements of the chain, in which at least the loading surface is made of a ferromagnetic material.
Such magnetic field generation means are constituted by two permanent magnets, which are arranged at two parallel rails formed in the guide and are arranged vertically, so that one has its north pole directed upward and the other has its south pole directed upward.
A cross-member, made of ferromagnetic material, is also present below said permanent magnets and covers approximately the entire width of the guide, so that the lines of force of the magnetic field generated by the permanent magnets are closed in a lower region through said cross-member and in an upper region through the conveyance element, which is therefore attracted vertically toward the guide.
The main drawback of this third known type of conveyor belt is that it requires the use of ferromagnetic material to provide the loading surface of the conveyance elements, and therefore the conveyor belt requires a lubrication system in order to ensure its regular and smooth operation, which is required for example when conveying bottles, particularly bottles containing beer or carbonated beverages.
Moreover, said conveyance elements are scarcely suitable if it is necessary to convey products that may be damaged by contact with metallic surfaces.
Another drawback of this third known type of conveyor belt is that the permanent magnets must be arranged within the rails so that their respective magnetic poles are oppositely orientated, thus making it difficult to perform assembly and maintenance and accordingly increasing the overall production and management costs of the conveyor belt.
Another drawback is that an error in positioning the permanent magnets may lead to poor operation of said belt.
A fourth known type of conveyor belt, also provided with means for generating a magnetic field which are arranged inside a guide, has conveyance elements made of plastics, thus obviating the drawbacks that arise from providing the loading surface by means of ferromagnetic material; the magnetic field is closed across a pivot, which is made of ferromagnetic material, is arranged transversely to said guide, and rotatably connects each conveyance element to the adjacent conveyance elements.
In this fourth known type of conveyor belt, generation of the magnetic field is entrusted to a pair of magnets arranged horizontally side by side; the first magnet is arranged so that its north pole is directed upward and the second magnet is arranged so that its south pole is directed upward, and said magnets extend laterally until they reach the opposite ends of the pivot.
As an alternative, said magnetic field can be generated by means of a magnet that has, in its left half, the north pole arranged upward and the south pole arranged downward and, in its right half, the south pole arranged upward and the north pole arranged downward.
The main drawback of this fourth known type of conveyor belt is that the permanent magnets must be arranged inside the guide so that their respective magnetic poles are oppositely orientated, thus making assembly and maintenance troublesome and accordingly causing an increase in the overall production and operating costs of the conveyor belt.
Another drawback is that providing a single magnet in which the left half has the north pole arranged upward and the south pole arranged downward and the right half has the south pole arranged upward and the north pole arranged downward is onerous and causes a high overall production cost of the conveyor belt.
Another drawback of this fourth known type of conveyor belt is that, since the attraction force is applied to the pivot, and therefore in the central region of the conveyance element, a perfectly horizontal arrangement of the loading surface is not ensured, since the lateral ends of said loading surface can flex or tilt slightly.

SUMMARY OF THE INVENTION

The aim of the present invention is to solve the above-noted problems, eliminating the drawbacks of the cited background art, by providing a device that allows to transfer semifinished or finished products on a surface even if the path comprises one or more curved portions.
Within this aim, an object of the invention is to ensure its easy assembly and to allow quick and easy execution of maintenance operations.
Another object is to provide a device that ensures high planarity even in the presence of long conveyance portions.
Another object of the invention is to require low power to move a chain of a conveyor belt.
A further object of the invention is to allow to move fragile and/or easily damageable products in a regular fashion.
A still further object is to provide a device that is structurally simple and has low manufacturing costs.
This aim and these and other objects that will become better apparent hereinafter are achieved by a guide, particularly for conveyor belts, inside which it is possible to accommodate first means for generating a magnetic field, said guide being able to support slidingly a chain that is composed of a plurality of conveyance elements provided with second means for their mutual engagement, said second means being made at least partially of ferromagnetic material, characterized in that each one of said first means is constituted by a single permanent magnet, which has an approximately U-shaped cross-section and has at least one pair of wings that protrude upward, said magnet being insertable within a complementarily shaped receptacle formed inside said guide.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will become better apparent from the following detailed description of a preferred but not exclusive embodiment thereof, illustrated by way of non-limiting example in the accompanying drawings, wherein:
FIG. 1 is a top view of a curved portion of a guide according to the invention, above which a portion of a chain is shown;
FIG. 2 is a sectional view of the invention, taken along the line II-II of FIG. 1;
FIG. 3 is a sectional view, taken along a transverse plane, of the invention according to a second embodiment;
FIG. 4 is a sectional view, taken along a transverse plane, of the invention according to a third embodiment;
FIG. 5 is a sectional view, taken along a transverse plane, of a further embodiment of the guide according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the embodiments that follow, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other embodiments.
With reference to the figures, the reference numeral 1 designates a guide, particularly for a conveyor belt 2, which is optionally provided with a curved portion structure and has a transverse cross-section that is approximately U-shaped externally so as to form, at its lateral ends, two rails 3 a and 3 b that protrude upward from a bottom 4, which is arranged approximately horizontally.
The rails 3 a, 3 b, which have an approximately rectangular cross-section, are mutually parallel so as to form, in the interspace between them, a seat 5, which is open in an upper region and has a rectangular cross-section; said seat is delimited laterally by two side walls 6, constituted by the mutually facing sides of the rails 3 a and 3 b.
An approximately U-shaped receptacle 7 is formed below and inside the guide structure 1, is open in a lower region, and surrounds the bottom 4 of the guide 1.
The lateral ends 7 a of the receptacle 7, which protrude vertically upward, are advantageously obtained at and inside the rails 3 a and 3 b and are slightly lower than said rails; further, the lateral ends 7 a are axially offset with respect to the rails 3 a and 3 b; in particular, there is an axial offset in the direction of the adjacent side wall 6.
The guide 1 can be made for example of plastics, preferably having good wear-resistance properties and having low friction coefficients with respect to other plastic or metallic materials.
First means for generating a magnetic field are provided inside the guiding and supporting structure of the guide 1; each means is constituted by a single permanent magnet 8, which has an approximately U-shaped cross-section and is shaped approximately complementarily with respect to the receptacle 7, in which it can be inserted so that its wings 9 protrude upward, so that said wings are contained within the lateral ends 7 a of said receptacle.
Advantageously, the height of the wings 9 of the permanent magnet 8 is approximately equal to the height of the lateral ends 7 a of the receptacle 7, so that the wings 9 are arranged so that one surface is adjacent to the respective side wall 6 of the seat 5.
In said permanent magnet, the north pole and the south pole are arranged respectively at the two opposite wings 9.
A plurality of individual magnets can be arranged along the guide 1 so that they are longitudinally spaced from each other and are arranged at chosen curved or straight portions of said guide at a chosen mutual distance.
A chain 10 is supported slidingly above the guide 1 and is constituted by a plurality of conveyance elements 11, which are provided, in an upper region, with a loading surface 12, which is approximately flat and has an approximately rectangular plan shape.
Such loading surface rests, at its lateral ends, on the two rails 3 a and 3 b.
Advantageously, the loading surface 12 can be made of plastics, preferably having good wear-resistance properties and a low friction coefficient with respect to the material of which the guide 1 is made; as an alternative, it can be made of ferromagnetic material.
Below said loading surface, each conveyance element 11 has two first bushes 13, which externally have an approximately cylindrical shape and protrude frontally from said loading surface in the direction of a longitudinal axis of the guide when the conveyance element rests thereon.
The first bushes 13 are provided with a hole along one of their longitudinal axes, which is perpendicular to the longitudinal central plane of the guide 1, and are advantageously aligned transversely to the guide 1, at a mutual distance that is shorter than the distance formed between the side walls 6 of the seat 5, so that when the conveyance element rests on the guide 1 the first bushes are accommodated within the seat 5.
Moreover, a second bush 14 protrudes below the loading surface, in the opposite direction with respect to the first bushes 13, and has a slot or a hole along its own longitudinal axis and is arranged so that said axis is perpendicular to the longitudinal central plane of the guide 1; said second bush is narrower than the mutual distance between the first bushes, so that it can be accommodated within the seat 5 between the first two bushes of the adjacent conveyance element 11.
Said first and second bushes can be made of the same ferromagnetic or non-ferromagnetic material as the loading surface 12 and can be optionally obtained monolithically therewith.
Each conveyance element 11 is rotatably connected to the next by means of a pivot 15, which is made of ferromagnetic material and can be inserted in the two first bushes 13 and in the second bush 14, so as to ensure driving of the entire chain 10, the bushes 13, 14 and pivot 15 forming second engagement means.
Conveniently, the diameter of said pivot is larger than the diameter of the holes formed in the first bushes, so that it can be inserted therein with interference, and a diameter that is smaller than the diameter of the slot or hole formed in the second bushes, so as to allow relative rotation between two adjacent conveyance elements also on the plane of travel of the conveyor belt, which is generally but not necessarily horizontal.
When the chain 10 is arranged above the guide 1, each pivot 15 is accommodated within the receptacle 5 and lies transversely between the side walls 6 thereof.
The operation of the guide 1, particularly for conveyor belts, entails that once each conveyance element 11 has been arranged on the guide 1, the lines of flux of the magnetic field generated by the permanent magnet 8 close across the pivot 15, which is made of ferromagnetic material and is arranged between the upper ends of the wings 9 of the magnet 8, which have opposite magnetic polarities.
Accordingly, said magnetic field keeps the chain 10 in contact with the guide 1, preventing its lifting at curved portions; moreover, if dirt or debris penetrates between the rails and the conveyance elements 11, said elements are still attracted by said guide and adhere to it again as soon as they have moved beyond the portion affected by the dirt.
If the loading surface 12 of the conveyance elements 11 is made of ferromagnetic material, the lines of flux of the magnetic field generated by the permanent magnet close through the loading surface 12; in this case, optimum stability and planarity of the chain 10 are ensured, since the conveyance elements are attracted toward the rails 3 a and 3 b at their lateral ends.
The shape of the permanent magnet 8 and of the receptacle 7 formed inside the guide 1 allows easy assembly of a conveyor belt 2 and easy removal of said magnet for maintenance or replacement.
Further, since the magnet is protected in an upper region by the guide 1, it cannot be damaged by external agents or by debris penetrated beneath the chain 10, so that a conveyor belt that comprises the guide 1 ensures high reliability in operation.
Moreover, it is possible to arrange along the longitudinal extension of the guide a chosen number of magnets arranged in chosen points of the guide 1, which are curved or rectilinear, so as to ensure a preset attraction force of the chain toward the guide, required in order to avoid the lifting of its outer end.
In this manner, it is possible to minimize the friction of the chain on the guide, so as to require minimum power absorption for driving said chain.
It is advantageous to arrange one or more permanent magnets both along curved portions of the guide 1 and along straight portions of said guide that are very long and at which the tension of the chain may decrease and accordingly allow the lifting of one or more conveyance elements 11.
FIG. 3 illustrates a second embodiment of the guide 101 according to the invention, particularly for a conveyor belt, which comprises a permanent magnet 108 that has an approximately U-shaped cross-section and has a first pair of outer wings 109, which protrude upward at its lateral ends, and a second pair of inner wings 116, which protrude upward proximate to the first wings 109 and are arranged internally with respect to said first wings.
The second wings 116 are lower than the first wings 109; conveniently, the second wings 116 are lower than the guide 101 at its bottom 104.
Each second wing 116 further has the same magnetic polarity as the first wing that it flanks; in the example shown in FIG. 3, the first and second wings arranged on the left constitute the north pole of the permanent magnet 108 and the first and second wings arranged on the right constitute the south pole of said magnet.
A receptacle 107 that is shaped complementarily to the permanent magnet 108 is formed within the guide structure 101, and its lateral ends 107 a accordingly have a step-like cross-sectional configuration and affect or extend by, at their lower regions, which face each other and are directed toward the inside of the guide 101, the lateral ends of the bottom 104.
The presence of the second pair of wings 116 allows to ensure a powerful attraction of the conveyance elements toward the guide and further allows to obtain a magnetic field in which the lines of flux are closed both across the loading surface, if it is made of ferromagnetic material, and across the pivot.
FIG. 4 is a view of a third embodiment of the guide 201 according to the invention, particularly for a conveyor belt, in which the U-shaped receptacle 207 is formed entirely at the bottom 204 of the guide 201, its lateral ends 207 a being arranged approximately at the lateral ends of the bottom 204.
In this third embodiment, the lines of flux of the magnetic field generated by the permanent magnet 208 contained inside the receptacle 207 are closed by means of the pivot, not shown in the figure, which must be made of ferromagnetic material.
Starting from each one of the embodiments described above, it is possible to obtain a single guide, particularly for a conveyor belt, that is constituted by two or more guides of the types described above, which are arranged longitudinally side by side and on which a chain can slide which is constituted by a corresponding number of chains of the type described above arranged side by side, this embodiment being particularly suitable for conveying large quantities of products.
FIG. 5 illustrates, by way of example, a further embodiment of the guide 301 according to the invention particularly for a conveyor belt, on which three pairs of rails 303 a, 303 b arranged side by side are formed, and which comprises three permanent magnets 308, which are accommodated within the guide 301 and are arranged mutually side by side.
A chain may be supported slidingly by said guide; a single conveyance element 311 of said chain is shown for the sake of simplicity.
It has thus been found that the invention has achieved the intended aim and objects, a guide having been provided which allows to move semifinished or finished products on a surface even if the path comprises one or more curved portions.
Another object achieved by the invention is to ensure its easy assembly and allow quick and easy execution of maintenance operations.
Another object achieved is to ensure high planarity even in the presence of long conveyance portions.
Another object achieved by the invention is to require low power to drive a chain of a conveyor belt.
Another object achieved by the invention is to allow to move in regular manner products that are fragile and/or easily damageable.
The materials used, as well as the dimensions of the individual components of the invention, may of course be more pertinent according to specific requirements.
The various means for performing certain different functions need not certainly coexist only in the illustrated embodiments but can be present per se in many embodiments, including ones that are not illustrated.
The characteristics indicated as advantageous, convenient or the like may also be omitted or be replaced with equivalents.
The disclosures in Italian Patent Application No. TV2004A000115 from which this application claims priority are incorporated herein by reference.

Claims

1. A guide for conveyor belts, comprising: a supporting and guiding structure; first means for generating a magnetic field accommodated in said structure; a chain supported at the guide that is composed of a plurality of conveyance elements; second engagement means for mutual engagement of said conveyance elements, said second engagement means being made at least partially of a ferromagnetic material, and wherein said first engagement means is constituted by single permanent magnets, each of said magnets having a U-shaped cross-sectional configuration with at least one pair of wings that protrude upward, each one of said magnets being insertable within a complementarily shaped receptacle formed inside the guide structure.

2. The guide of claim 1, wherein said guiding structure has a transverse cross-sectional configuration that is externally U-shaped, so as to form at lateral ends thereof two rails that protrude upward from a bottom thereof that lays horizontally, said rails having a rectangular cross-section and being mutually parallel.

3. The guide of claim 2, wherein said rails form an interspace with a seat that is open upward and has a rectangular cross-section, said seat being delimited laterally by two side walls constituted by mutually facing sides of said rails.

4. The guide of claim 3, wherein said receptacle is formed downward and internally with respect to said guide structure and is U-shaped, said receptacle being open downward and surrounding said bottom of said guide structure.

5. The guide of claim 4, wherein said receptacle has lateral ends which protrude vertically upward, are formed at and within said rails and have a height that is slightly lower than a height of said rails.

6. The guide of claim 5, wherein said lateral ends are axially offset with respect to said rails, preferably toward said adjacent side wall.

7. The guide of claim 6, wherein said at least one pair of wings of said permanent magnet are provided so as to be insertable within said lateral ends of said receptacle.

8. The guide of claim 7, wherein said wings of said permanent magnet have a height that is substantially equal to said height of said lateral ends of said receptacle, said wings being arranged with one surface thereof adjacent to a respective side wall of said seat.

9. The guide of claim 8, wherein north and south poles of said permanent magnet are arranged respectively at said two opposite wings.

10. The guide of claim 9, comprising a plurality of individual magnets arranged along said guide structure, said individual magnets being longitudinally spaced from each other, and arranged at selected curved and/or straight portions of said guide structure, at a selected mutual distance.

11. The guide of claim 10, wherein each one of said conveyance elements is slidingly supported by said guide structure and is provided, in an upper region thereof, with a loading surface that is substantially flat, has a rectangular plan shape, and rests at lateral ends thereof above said pair of rails.

12. The guide of claim 11, wherein said loading surface is made of plastics, preferably plastics with good wear-resistance properties and a low friction coefficient with respect to a material of which said guide structure is made.

13. The guide of claim 11, wherein said loading surface is at least partially made of ferromagnetic material.

14. The guide of claim 3, wherein each said conveyance element has an upper loading surface, said second engagement means comprising two first bushes, which are arranged below said loading surface, are externally cylindrical and protrude from said loading surface in a direction of a longitudinal axis of said guide structure when the respective conveyance element rests on said guide.

15. The guide of claim 14, wherein said first bushes are each provided with a hole along a longitudinal axis thereof, said longitudinal axis of the hole being perpendicular to a longitudinal central plane of said guide structure, longitudinal axes of said first bushes being aligned transversely to said guide structure, at a mutual distance that is shorter than a distance between said side walls of said seat, said first bushes being accommodated within said seat when the respective conveyance element rests on said guide structure.

16. The guide of claim 15, comprising a second bush that protrudes below said loading surface, in an opposite direction with respect to said first bushes, said second bush having a slot or a hole along a longitudinal axis thereof, and being arranged with said longitudinal axis thereof perpendicular to said longitudinal central plane of said guide structure, said second bush being narrower than a mutual distance between said first bushes, so as to be accommodatable within said receptacle between said two first bushes of an adjacent conveyance element.

17. The guide of claim 16, wherein said first and second bushes are preferably made of a same ferromagnetic or non-ferromagnetic material as said loading surface and are formed monolithically therewith.

18. The guide of claim 17, further comprising pivots, each one of said conveyance elements being rotatably connected to a next one by way of a pivot of said pivots, which is preferably made of ferromagnetic material and is insertable within said two first bushes and said second bush, so as to ensure driving of the entire said chain, each one of said pivots being accommodated, when said chain is arranged above said guide structure, inside said seat and being arranged transversely between said side walls of said seat.

19. The guide of claim 18, wherein a diameter of a said pivot is smaller than a diameter of the holes provided in the first bushes, so that said pivot is insertable therein with interference, and is smaller than a diameter of said slot or hole formed in said second bushes, so as to allow a relative rotation between two adjacent said conveyance elements on a plane of travel of said conveyor belt.

20. The guide of claim 4, wherein said permanent magnet has U-shaped cross-sectional configuration, which forms a first pair of external wings, protruding upward at lateral ends of said permanent magnet, and a second pair of internal wings, which protrude upward proximate to said first wings and are arranged internally with respect to said first wings.

21. The guide of claim 20, wherein said second wings are lower than said first wings, a height of said second wings being lower than a height of said guide structure at said bottom.

22. The guide of claim 21, wherein a north and a south pole of said permanent magnet are arranged respectively at said two opposite first wings, each one of said second wings having a same magnetic polarity as said first wing, to which the second wing is laterally adjacent.

23. The guide of claim 22, wherein the lateral ends of said receptacle, which is shaped complementarily with respect to said permanent magnet, have a step-like cross-sectional configuration and extend by, at lower regions thereof, which face each other and are directed toward an inside region of said guide structure, lateral ends of said bottom of said guide structure.

24. The guide of claim 23, wherein said receptacle is U-shaped and is formed entirely at said bottom of said guide structure, lateral ends thereof being arranged at lateral ends of said bottom.

25. The guide of claim 4, comprising at least two said guide structures, which are arranged longitudinally side by side, said guide structures being able to support slidingly a corresponding number of said chains arranged side by side.

26. The guide of claim 1, wherein said guide structure is made of plastics, preferably plastics having better wear-resistance properties and lower friction coefficients with respect to other plastic, ferromagnetic, and metallic materials from which the chain, the engagement elements and magnets are made.