Link of conveyor chain

A link of a conveyor chain is connectable to a similar and adjacent link and has a main base body with two shoulders, protruding upward from ends of transverse sides of the main base body. Ends of a pair of first and second shafts are associated with the pair of shoulders and first rollers are rotatably associated with the shafts. Second rollers are associated on the pair of first and second shafts and are supported in a loaded condition by at least one pair of first supporting elements, activatable when a load passes. A third shaft, with which third rollers are associated rotatably, is further provided that is supported by at least one pair of second supporting elements, the ends of the third shaft being free.

BACKGROUND OF THE INVENTION

In the provision of industrial systems for bottling liquids or for packaging goods of various kinds, the design of suitable systems for moving the products from one processing station to the next and toward the store is very important.

In performing the production cycles provided by these systems, it is often necessary to convey and stop the conveyed products in chosen positions, so as to be able to perform the various steps provided by said process, such as for example the filling of bottles, their closure, or the packaging of products of various kinds, or the accumulation of packages or containers.

Known types of conveyor chain, composed of a plurality of links which are mutually interconnected so as to form a chosen path, which can comprise straight and curved portions, are currently in use for moving goods within systems in which the working cycles provide for conveying or stopping the products in one or more positions.

One particularly strongly felt need is to allow the products to stop in the chosen positions without requiring the simultaneous stopping of the conveyor chain, which would entail high complexity in production and high costs for its operation.

For this purpose, it is known to manufacture conveyor chains which are constituted by interconnecting several links, each of which comprises a base body which has a substantially rectangular plan shape and on the transverse sides of which one or more shafts are supported which are arranged longitudinally with respect to the base body and transversely to the direction of advancement of the products on said chain; a plurality of rollers is associated with said shafts so that they can rotate freely and constitute the upper conveyance surface of the chain.

A first known type of link provides, on the transverse sides of the base body, a plurality of seats which are approximately U-shaped and are open upward for supporting the one or more shafts, the ends of which are inserted from above into said seats.

A second known type of link has, at the transverse sides of its base body, a plurality of through holes, which are for example aligned in pairs and within which the ends of the one or more shafts are inserted and thus supported.

In both of these known embodiments, if the products to be moved have substantial dimensions and/or weights, the shafts, owing to their longitudinal extension, are made to rest, in one or more intermediate points thereof, on a corresponding number of supports, which protrude upward from the base body and have a seat for rotatably accommodating a portion of said shaft.

The presence of the rollers in such links of the known type allows to convey the products and to stop them without having to interrupt the movement of the conveyor chain.

The moved product can in fact be blocked in the chosen position by means of a retention barrier without generating an intense friction force with respect to the chain thanks to the interposition of the rollers, which by rotating about the shaft that supports them reduce drastically the extent of such force; in this manner, the presence of stationary objects on the chain does not hinder the advancement of the chain.

The main drawback that can be observed in these known types of conveyor chain is that they have high wear of the intermediate supports, since the shaft that rests on them, if turned by the rollers that it supports, slides continuously on said intermediate supports, even in the presence of light loads on the conveyor chain.

Another drawback of known types of conveyor chain is that since each shaft rests directly on the corresponding intermediate support, it is extremely difficult to clean this region of the conveyor chain, and therefore debris from the outside environment or from the conveyed products, such as for example dust or splinters caused by the breakage of glass bottles, can penetrate between the shaft and the intermediate supports, increasing the drag of the chain and accelerating its wear; accordingly, long line downtimes are necessary in order to perform the required cleaning operations.

Another drawback of such known types of conveyor chain is that at the intermediate supports there is a considerable discontinuity in the upper supporting surface, which may give rise to an imperfect placement of the product on the chain, especially when said product has a narrow resting base, consequently hindering the correct execution of the cycle of the system within which said chain is inserted.

SUMMARY OF THE INVENTION

The aim of the present invention is to solve the above-mentioned problems, eliminating the drawbacks of the cited background art, by providing a device which allows to achieve low wear of the conveyor chain, even if it is used to convey material having a certain weight or if axially very long shafts are used.

Within this aim, an object of the present invention is to provide a device which allows quick and easy cleaning, so as to reduce line downtimes.

Another object is to provide a device which allows optimum placement of the conveyed products even if said products have a narrow resting base.

Another object is to provide a device which is structurally simple and has low manufacturing costs.

This aim and these and other objects, which will become better apparent hereinafter, are achieved by a link of a conveyor chain, which comprises means for articulated connection to a similar and adjacent link and a main base body which comprises two shoulders, which protrude upward from the ends of the transverse sides of said main base body and are arranged parallel to the direction of advancement of said chain, the ends of a pair of first and second shafts being associated with said pair of shoulders, first rollers being rotatably associated with said shafts, characterized in that second rollers are associated on said pair of first and second shafts, have a smaller diameter than said first rollers, and are supported in a loaded condition by at least one pair of first supporting elements, which can be activated when a load passes, protrude from said main base body and lie or not on a same plane which is transverse with respect to said pair of first and second shafts, and in that it comprises a third shaft, with which third rollers are associated rotatably, said third shaft being supported by at least one pair of second supporting elements, which protrude from said main base body and lie on a plane which is parallel and distinct with respect to the plane of arrangement of said first supporting elements, the ends of said third shaft being free.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the exemplary embodiments that follow, individual characteristics, given in relation to specific examples, may actually be interchanged with other different characteristics that exist in other exemplary embodiments.

Moreover, it is noted that anything found to be already known during the patenting process is understood not to be claimed and to be the subject of a disclaimer.

With reference to the figures, the reference numeral1designates a link of a conveyor chain according to the invention, which is constituted by a main base body2, which is approximately flat and has an approximately rectangular plan shape.

Two wings6can protrude downward from the base body2, in its central region, and are preferably L-shaped and arranged symmetrically with respect to a central plane of the link1.

The link1comprises known articulation means for articulated connection to a similar and adjacent link, so as to allow the provision of a conveyor chain which is constituted by a succession of multiple links1, which are mutually identical and are arranged consecutively with respect to each other along the advancement direction of said chain.

Said articulation means for articulated connection are constituted by a lug3, which is arranged between the wings6, protrudes at the front and centrally from the main base body2, and has an approximately trapezoidal plan shape, with its shorter parallel side directed forward.

A through slot or hole4is formed on the lug3, proximate to its front end3a, and its axis is arranged transversely with respect to the advancement direction of the conveyor chain.

The lug3can be accommodated within an approximately complementarily shaped first central seat5, which is formed centrally at the rear edge2aof the main base body2of an adjacent link1; the first central seat5has, in plan view, an approximately rectangular shape, which is slightly wider than the lug3, and is open at the rear edge2a, so as to allow the insertion of said lug within said seat with a chosen functional play.

The first wings reach the lateral edges5aof the first central seat5.

Two ridges7are formed on the wings6at the lateral edges5a, and a receptacle7ais formed therein, has a preferably circular cross-section and is open toward the inside of the link1, in order to support the ends of a transverse pivot, not shown in the figure, which can be inserted within the through slot or hole4aformed in the lug3so as to ensure the connection between two consecutive links1.

Said pivot has a smaller diameter than the through slot or hole4a; since the first seat5further is wider than the lug3, relative rotation between two adjacent links1on the conveyance plane is allowed and occurs at curved portions of the conveyor chain.

The link of conveyor chain1according to the invention can therefore be used both to provide straight conveyance portions and curved conveyance portions, according to the requirements of each specific case.

Two tabs8can protrude radially in the opposite direction from the lower ends of the wings6, each protruding toward the outside of the link1; the tabs8can be inserted slidingly within complementarily shaped seats formed on a guide, which is not shown in the figures, and which slidingly supports the links1, so as to contrast forces acting in the direction for lifting said links, which can occur for example at curved portions of the conveyor chain.

Two shoulders10aand10bprotrude upward at the lateral ends of the transverse sides of the main base body2and are arranged parallel to the advancement direction of the chain; suitable first and second seats10c,10dare formed thereon and are mutually aligned along an axis which is longitudinal with respect to the main base body2and transverse to the advancement direction of the chain; the ends of two first and second shafts, designated by the reference numerals9aand9b, are associated with said first and second seats10c,10d, and said first and second shafts are arranged on a same plane which is approximately parallel to the plane of arrangement of the surface of the main base body2from which the two shoulders10aand10bprotrude.

A plurality of first rollers14provided with an axial hole is associated rotatably with each of the first and second shafts9aand9b.

At least two first supporting elements protrude upward from the main base body2, each such supporting element being constituted by a pair of protrusions12a,12band12c,12d, which are arranged in pairs on a same plane which lies transversely to said pair of first and second shafts.

As an alternative, as shown inFIG. 6, the protrusions may be arranged on mutually different planes.

Each protrusion has, in plan view, an approximately rectangular shape, is parallel to the shoulders10aand10b, and is advantageously arranged in a mirror-symmetrical manner with respect to the central axis which lies transversely to the main base body2.

Each protrusion, in a side view, is shaped approximately like an inverted right-angled trapezoid, in which the shorter parallel side is arranged upward and the longer parallel side is rigidly coupled to the main base body.

One or more third seats13are provided above each protrusion, at the shorter parallel side, and have an approximately semicircular cross-section; the complementarily shaped lateral surfaces of a respective second roller15interact on said third seats in the loaded condition for said link, said second roller being perforated axially and having a smaller diameter than the first rollers14and the third seats13.

The first rollers14are arranged along the entire axis of the pair of first and second shafts9aand9b, except for the regions where the protrusions arranged in pairs12a,12band12c,12dprotrude from the main base body2, and second rollers15act thereat and advantageously have a rolling surface which is centrally concave and is arranged between two flat lateral shoulders. Since the second rollers15have a smaller diameter than the third seats13and are supported rotatably by the pair of first and second shafts9aand9b, they do not rest on the third seats when the pair of first and second shafts is arranged in a straight configuration, for example when no load is present on the first rollers14. The link further comprises a third shaft9c, which lies on the same plane of arrangement as the first and second shafts9aand9band with which first rollers14again are associated so that they can rotate freely. The third shaft9cis supported by at least one pair of second supporting elements, which protrude from the main base body2and are each constituted by two lugs51aand51b,which have a slotted incision or guide in the upper surface which is adapted to receive and support said third shaft. The two lugs51aand51bare arranged along a distinct plane, which is transverse with respect to said third shaft and is also distinct with respect to the plane of arrangement of said first supporting elements. Advantageously, said two lugs are each arranged in the space that is not comprised between said pair of first supporting elements and are therefore adjacent to said pair of shoulders. Further, the ends52aand52bof the third shaft9care free and not connected to the two shoulders10aand10b.

The first rollers14, associated with the third shaft9cat the ends52aand52b,act rotatably on complementarily shaped guides53aand53b, which protrude from the main base body2in a region which is adjacent to the pair of shoulders10aand10b.

The third shaft can be interposed centrally between said first and second shafts or be arranged laterally to one of them. The operation of the link of conveyor chain according to the invention entails that if no load or a light load, constituted for example by an empty bottle, is present thereon, the pair of first and second shafts9aand9bhas an approximately straight non-deformed configuration, so that the second rollers15are raised with respect to the respective facing third seat13.

In this operating condition, the pair of first and second shafts9aand9bis rotatably associated only with the shoulders10aand10b, while the first and second rollers14and15are free to rotate in order to allow relative sliding of the product that they support with respect to the link1, for example if said product supported thereby is locked in a chosen position by a retention barrier; low drag opposing the advancement of the conveyor chain is thus generated.

If the load conveyed by the link1is heavy, the two first and second shafts9aand9bare arranged in a deformed configuration; if the weight of said load exceeds a preset value, which can be defined for example analytically or experimentally, the lateral surface of the second rollers15makes contact with the corresponding surface of the third seat13, so as to constitute a supporting point for the two first and second shafts.

In this condition, the second rollers15do not rotate freely, since they are locked by the friction between its lateral surface and the surface of the third seat13; the presence of the second rollers15, however, avoids the wear of the protrusions12a,12b,12cand12d, since there is no direct contact with the two first and second shafts, which rotate, and the surface of the third seat13, which is fixed.

Further, the second rollers15rest on the surface of the third seat13, remaining locked in their rotation, only if the weight of the conveyed load exceeds a preset value; wear processes are thus slowed further, since if a lightweight load is conveyed, the second rollers15are not in contact with the protrusions and therefore can rotate freely, no action being applied to the protrusions.

If debris, constituted for example by glass splinters caused by the breakage of conveyed bottles or by dirt from the surrounding environment, occurs on the link1, it is further very easy to clean said link also at the central support.

This applies also to the third shaft9cat the ends52aand52b, which are not supported by the two shoulders10aand10b.

Moreover, the presence of the second rollers15allows to obtain good uniformity of the upper loading surface, since the difference between the outside diameters of the first and second rollers can be very small; good positioning is therefore ensured even in the case of products which have a narrow resting base.

It has thus been found that the invention has achieved the intended aim and objects, an invention having been provided which allows to ensure low wear thereof during operation as well as quick and easy cleaning thereof, so as to require reduced line downtimes.

Finally, the invention allows optimum positioning of the conveyed products, even if said products have a narrow resting base.

Of course, the materials used, as well as the dimensions that constitute the individual components of the invention, may be more pertinent according to specific requirements.

The various means for performing certain different functions need not certainly coexist only in the illustrated embodiment, but may be present per se in many embodiments, including ones which 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. TV2005A000121 from which this application claims priority are incorporated herein by reference.