WO2016092500A1

WO2016092500A1 - Link for chain for articles conveyor

Info

Publication number: WO2016092500A1
Application number: PCT/IB2015/059511
Authority: WO
Inventors: Andrea Andreoli; Guido Marchiani; Antonio Fiore
Original assignee: Rexnord Flattop Europe S.R.L.
Priority date: 2014-12-10
Filing date: 2015-12-10
Publication date: 2016-06-16
Also published as: DE112015005563T5

Abstract

A link (15) for article conveyor chain (10) is proposed, the chain (10) comprising a sequence of links (15). The link (15) is suitable for being coupled in an articulated manner to at least one adjacent link in the sequence in such a way as to allow for arching of the chain (10). The link (15) defines a respective portion of the resting surface (As) for the articles being transported. The link (15) comprises a first (15₁) and a second link element (15₂), and coupling means (25i,30i,45i-55i;25₂-45₂;45) for coupling together the first (15₁) and the second (15₂) link elements that can move with respect to each other on a plane that is parallel to said respective portion of the resting surface (As).

Description

Title: Link for chain for articles conveyor

The solution in accordance with one or more embodiments of the present invention generally relates to article conveyors. More particularly, the solution refers to a shutter chain (for article conveyors) with improved mechanical properties.

An article conveyor (hereinafter, conveyor) typically comprises a closed loop support element suitable for supporting the articles and elements of movement (for example, electric motors, pinions and drive sprockets) for moving the support element thus allowing for the

transportation of the articles placed upon it along a predefined transport path.

A particularly common conveyor type uses as a chain for the support element (hereinafter, chain) which typically comprises a plurality of links which are hinged together and which as a whole define a resting surface for the articles to be transported.

This conveyor type, even though it is often used, exhibits drawbacks that preclude its greater use. This is mainly due to the fact that, where there is a curve in the transport path (and in particular at the outer surface of the curve) openings are formed (gaps) between adjacent links.

The presence of gaps, in addition to interrupting the continuity of the resting surface, can cause damages or injuries (for example, when, at the closure of the gap at the end of the curve, a foreign object - such as an article or the finger of an operator - remains into the gap) and can cause articles to fall from the chain (for example as a consequence of accelerating or decelerating which the articles are subject to when being transferred between chains that are moving at different speeds).

To avoid the occurrence of gaps in the curves, chains have been proposed (referred to as zero-gap, and discussed, for example, in EP926082, EP910540 and in EP 1375391) wherein each link comprises a link body and a plate with an arched profile that is capable of merging with the arched seating of the link body.

However, the known zero-gap chains, such as those discussed in EP926082, in EP910540 and EP 1375391, have links of a length interval (along a longitudinal direction of travel of the chain) and width (along a transverse direction orthogonal to the longitudinal direction) that are not adequate. In fact, for a given ratio of body hnk and plate, with an increasing hnk width (in order to achieve an adequate resting surface), there is an increase in the minimum radius of curvature of the body link and plate. This implies an increase in the length of the link along the longitudinal direction (in order to achieve hinging that will allow for the relative rotation between the body link and the plate in accordance with the minimum radius of curvature), and therefore an increased length interval.

As it is known, an increased length interval determines an increased minimum radius of curvature for the chain, which poses considerable constraints upon the transport path design phase.

Furthermore, in conveyors wherein the chain is moved by means of a gear-rack mechanism, and therefore jerkily, an increased length interval determines somewhat pronounced jerks (the distance traveled for each jerk being dependent upon the length interval between the links), and therefore poor chain movement fluidity. This can cause articles to fall from the chain, especially when such articles are of reduced weight.

In addition, an increased length interval determines excessive overall dimensions of the chain when it is curved around the pinion, a particularly critical circumstance when it is necessary to combine the adjacent ends of different chains.

Last, but not least, an increased length interval means that zero- gap chains are not suitable for replacing, in order to comply with new safety regulations, traditional chains (i.e. not-zero-gap) that are currently installed in many conveyors, in that they typically have reduced length intervals (not achievable using known zero-gap chains).

The applicant has faced the problems mentioned above and has devised a solution for a link that allows zero-gap chains to be obtained with improved mechanical properties, and in particular with a reduced interval and increased width, which at the same time offers a significant resistance to stresses.

In particular, one or more aspects of the solution in accordance with specific embodiments of the invention are indicated within the independent claims, with advantageous features of the same solution that are indicated within the dependent claims, the text of which is incorporated herein for reference (with any advantageous feature being provided with reference to a specific aspect of the solution in accordance with an

embodiment of the invention which applies, mutatis mutandis, to all other aspects therein).

More specifically, one aspect of the solution according to one or more embodiments of the present invention proposes a chain link for an article conveyor, the chain comprising a sequence of links. Said link is suitable for being coupled in an articulated manner to at least one adjacent link in the sequence in such a way as to allow for arching of the chain. Said link defines a respective portion of the resting surface for the articles being transported. Said link comprises a first and a second link element, and coupling means for coupling together the first and the second link elements. In the solution in accordance with one or more embodiments of the present invention, said coupling means comprise:

a coupling portion of the first link element, a coupling portion of the second link element, and a coupling element which is suitable for engaging in the coupling portion of the first link element and in the coupling portion of the second link element, a degree of mechanical play being anticipated between the coupling portion of the first link element and the coupling element in order to allow for relative movement of the first element and the second link element on a plane that is parallel to said respective portion of the resting surface, and

a further coupling portion of the first link element, the coupling element being suitable for engaging in said further coupling portion for coupling said link in an articulated manner to an adjacent link in the sequence in order to allow said arching of the chain.

In accordance with an embodiment of the present invention, the coupling portion of the first link element and the coupling element comprise respective regions of support in correspondence of which both the coupling portion of the first link element and the coupling element are supported during said relative movement, at least one of either the region of support of the coupling portion of the first link element or the region of support of the coupling element having a convex profile that permits said mechanical play.

In accordance with an embodiment of the present invention, said coupling means allow the first link element to move with respect to the second link element along a first arc of circumference described along said plane, wherein the region of support of the coupling element has a straight profile, and the region of support of the coupling portion of the first link element has an arched profile which describes a second arc of circumference which is substantially concentric, in plan view, to the first arc of a

circumference.

In accordance with an embodiment of the present invention, said coupling means allow the first link element to move with respect to the second link element along said first arc of a circumference around an axis that is perpendicular to said respective portion of the resting surface, the coupling means being spaced apart from, and not intersecting, said axis.

In a particular embodiment of the link, according to the present invention, the coupling element of the coupling means comprises a roller, while the coupling portion of the first link element comprises an eyelet with an inner surface defining a through hole, enabling the roller to be received therein in rolling manner. With the roller acting as a pivot, a normal sliding friction between the pivot and the eyelet is replaced by a rolling friction between the roller and the eyelet, thus resulting in less wear and prolonging the service life of the link. The roller can engage directly within the inner surface of the eyelet, but in accordance with a particular embodiment of the link according to the present invention the coupling means further comprise an intermediate connecting element between the inner surface of the first link element and the roller, the intermediate connecting element having a concave engagement surface that is suitable for fittingly engagement with a convex surface of the roller. As such a contact surface between the roller and the intermediate connecting element is relatively large, improving a distribution of the pressure applied to the roller during the use of the link in the chain. The intermediate connecting element can be formed with the eyelet out of one piece, or it can be integrally coupled to the eyelet or it may be a separate component. The intermediate connecting element is formed in such a way that movement of the roller inside the through hole allows for movement of the first link element and the second link element with respect to each other. The intermediate connecting element can be a replaceable or exchangeable part so as to remediate the possible internal wear of the coupling means affecting the intermediate connecting element by replacing the relatively simple intermediate connecting element. The intermediate connecting element may comprise or consist of a solid body constructed from wear-resistant material. The body may comprise on one side a groove or incision, which defines the concave surface that is complementary to the convex surface of the roller. In particular, the intermediate connecting element may comprise or consist of a shaped body in the form of a meniscus. In accordance with an embodiment of the present invention, the first link element comprises a plate-like portion having an arched lip support element, and the second link element comprises a plate-like portion having an arched region of contact that is suitable for being supported by the arched lip support element and designed to move by sliding along it; the coupling portion of the first link element comprises a protrusion extending along a first direction parallel to said plane and having a through hole which is suitable for receiving the coupling element along a second direction that is orthogonal to the first direction.

In accordance with an embodiment of the present invention, the region of support of the coupling portion of the first link element is located on an inner surface of the through hole.

In accordance with an embodiment of the present invention, said through hole has, along said second direction, a substantially hourglass form, the inner surface of the through hole comprising a further region of support with a profile that is substantially complementary with respect to the region of support.

In accordance with an embodiment of the present invention, said substantially complementary profile comprises a cusp profile.

In accordance with an embodiment of the present invention, the arched contact region comprises end-stop elements for limiting said relative movement.

In accordance with an embodiment of the present invention, the coupling portion of the second link element comprises a pair of eyelets extending from the respective plate-like portion and suitable for housing between them the coupling portion of the first link element, the coupling element being engaged with said pair of eyelets.

Another aspect of the solution according to one or more

embodiments of the present invention proposes a chain for conveying articles, in which the chain comprises a sequence of said links.

The solution in accordance with one or more embodiments of the invention, as well as additional features and its advantages, will be better understood with reference to the following detailed description, given purely as an indication and not limited, to be read in conjunction with the accompanying figures (in which corresponding items are shown with the same or similar references and wherein their explanations are for brevity not repeated). In this respect, it is expressly understood that the figures are not necessarily to scale (with some details that may be exaggerated and/or simplified) and that, unless otherwise indicated, they are simply used to illustrate conceptual structures and procedures. In particular:

Figure 1A shows a top view of a chain in accordance with one embodiment of the present invention;

Figures IB and 1C show pairs of top and section views from above and in section of the chain in two respective arched configurations in accordance with an embodiment of the present invention;

Figures 2A-2B show views from below the chain in straight and curved configurations, respectively, in accordance with one embodiment of the present invention;

Figure 3 shows an exploded lateral perspective view of two links of the chain;

Figures 4A-4C show views from below a link of the chain mesh in straight and curved configurations, respectively, in accordance with one embodiment of the present invention, and

the Figures 5A-5C show detailed views of the coupling means of a particular embodiment of the link according to the present invention, in respectively a side view (5A), a top view of a first position of the coupling element (5B) and a top view of a second position of the coupling element (5C).

With reference to Figure 1, it shows a top view of a chain 10 (i.e. of one of its portion) in accordance with one embodiment of the present invention. In the following, directional terminology (for example, high, low, top, bottom, side, central, longitudinal, transverse, vertical) associated with the chain 10 and its components will be used only in relation to their orientation within the figures, and will not be indicative of any specific usage orientation (among the many possible) of the same. The term

"substantially" will instead be used to take into account manufacturing tolerances (desired or undesired).

The chain 10 is particularly (though not necessarily) suitable to be used in an article conveyor (not shown in the figures), for industrial or civil use. In this regard, the conveyor, not limited to the present invention, will be discussed briefly recalling, if at all, functional elements that are relevant to the understanding of the invention.

The chain 10 is designed in such a way as to be able to curve (to the left, and, as shown in the figure to the right).

As shown in Figures IB and 1C, which show views from the top (left) and in section (right) of the chain 10 in arched configurations, the chain 10 can arch/flex upward (Figure IB) and downwards (Figure 1C), for example in order to be moved around pinions and sprockets. These arches, which are made possible by the link structure described below, also permit the use of the chain 10 in combination with chain tensioning systems, not shown, where relatively heavy metal cyhnders are placed on a resting surface (e.g. above) of the chain 10, followed and preceded by idle rollers that support the chain 10 from below. In the absence of tensioning systems, these arches allow the chain 10 to follow the profile of idle rollers that support the chain 10 along a section of the return transportation path of the conveyor (the chain 10 being basically de-tensioned over that return section).

The chain 10 comprises a plurality of links 15 (only four are shown in the figures) that identify, comprehensively, the resting surface As of the chain 10 for the transportation of the articles - with each hnk 15 defining a portion of the resting surface As. In the exemplary but non limiting embodiment illustrated, the chain 10 is comprised of an aligned

succession/sequence of links 15 that are coupled together in an articulated manner (thus allowing the chain 10 to arch), with each link 15 that is coupled in an articulated manner to an adjacent link 15 (for example, the next and/or the previous link) along a longitudinal direction of travel of the chain 10 (with such a structure that can be replicated indefinitely, thus obtaining a chain 10 of the desired length).

Each link 15 has a first link element (in the example shown, a link body) 15i and a second link element (in the example shown, a plate) 152 coupled together in a swiveling manner (by appropriate coupling means, discussed below), such that, at a curve in the transportation path of the conveyor, the plate 152 and link body 15i can move one relative to the other (relative movement) in a plane that is parallel to the respective portion of the resting surface As. As will be made clearer below, the relative motion between the link body 15i and the plate 152 of each link body 15 can be decomposed, on such a surface, to a movement of rotation about an axis of rotation AR (not visible in this figure) that is substantially orthogonal to the portion of the resting surface As as defined by link 15 and to a translation movement.

For ease of description, in the following, Figure 1A-1C will be discussed together with Figures 2A-2B, which show views from below the chain 10 in straight and curved configurations, respectively, with Figure 3, which shows an exploded perspective lateral view of two links 15 of the chain 10, and with Figures 4A-4C, which show views from below of a link 15 of the chain 10 in straight and curved configurations, respectively.

As shown in Figures 2A-2B and 4A-4C, the link body 15i (of each link 15) preferably comprises a plate-like portion 20i having an arched side 25i (preferably, the side facing the plate 152 along the longitudinal direction X) extending, in width (i.e. along a transverse direction Y that is orthogonal to the longitudinal direction X), with a circumference of arc profile substantially throughout the link 15, and an arched lip support element 30i (with ARC) protruding from a substantially central region 25i along the longitudinal direction X. Preferably, although not necessarily, the plate-like portion 20i and the arched lip support element 30i are made of a plastic material, and even more preferably, as shown, they are made in a

monolithic manner (for example, by means of plastics injection molding techniques).

As shown in Figure 3, the plate 152 (of each link 15) comprises a plate-like portion 202 in the form of a segment of a circle having, at one of its arched sides 252 (i.e. the side facing the link body 15i along the longitudinal direction X), an arched slot 302 which is suitable for cooperating with the arched side 25i and the arched lip support element 30i of the plate-like portion 20i of the link body 15i.

Preferably, as illustrated, the arched slot 302 presents, in width, a greater extension than the arched lip support element 30i, and is bounded by the end stop elements 352. In addition, the arched slot 302 extends in height (that is, along a vertical direction Z which is orthogonal to the longitudinal direction X and to the transverse direction Y, for about a half of the total thickness of the plate-like portion 2Ο2. In this way, the arched slot 302 and the end stop elements 352 define, in correspondence to the arched side 252 of the plate-like portion 2Ο2, an arched contact region 402 which is suitable for being supported by the arched lip support element 30i and for sliding along it (until, as best discussed below, the end stop elements 352, by abutting against the arched lip support element 30i, prevent any further sliding) in order to allow the relative movement between the link body 15i and the plate 152. Preferably, although not necessarily, the plate-like portion 2Ο2 and the arched slot 302 and the end stop elements 352 are made of a plastic material, and even more preferably, as shown, they are made in a monolithic manner (for example, by means of plastics injection molding techniques).

As discussed in greater detail below, the geometries relative to the link body 15i (plate-like portion 20i, arched side 25i and arched lip support element 30i) and the plate 152 (flat portion 202, arched side 252, arched slot 302, end stop elements 352 and arched contact region 4Ο2), together with the action of the aforementioned coupling means, allow the relative movement between the link body 15i and the plate 152 along an arc of circumference Al with a center at O (belonging to the axis of rotation AR) and radius Rl (see Figures 4A-4C), while avoiding the formation of spaces (gaps) between adjacent links on the resting surface As of the chain 10 (zero-gap chain).

In the solution in accordance with embodiments of the present invention, the coupling means comprise a coupling portion 45i of the link body 15i, a coupling portion 452 of the plate 152 (with the possible

implementations of these coupling portions 45i, 452 which will be discussed shortly), and a pivot (or other coupling element) 45, for example of a plastic and/or metal material. The pivot 45 is suitable for engaging with the coupling portions 45i, 452, with a mechanical play to allow said relative movement, which is provided between the coupling portion 45i and the pivot 45 (i.e. between respective support portions in correspondence of which one of either the coupling portion 45i or the pivot 45 is supported during said relative movement), and, as discussed below, in a further coupling portion of the link body 15i for the coupling in an articulated manner to an adjacent link in the sequence (thus allowing the chain 10 to arch).

Preferably, in order to obtain said mechanical play, at least one of either the region of support of the coupling portion 45i of the link body 15i or the region of support of the pivot 45 has a convex profile.

In the exemplary but non limiting embodiment illustrated, the region of support of the pivot 45 has a straight profile, and the region of support of the coupling portion 45i has an arched profile that allows the pivot 45 to slide tangentially to the region of support, parallel to this plane. As will become apparent from the following description, this tangential sliding is permitted by the movement of the pivot 45 along the transverse direction Y (transverse movement) and the inclination of the pivot 45. In this way, in correspondence with a curve of the transport path of the conveyor, the plate 152, which is integral to the pivot 45, can move in relation to the link body 15i along the arc of circumference Al.

To achieve this, in accordance with an embodiment of the present invention (which can be better appreciated from Figures 4A-4C) the region of support of the coupling portion 45i has a profile that describes an arc of circumference A2 (of radius R2, less than the radius Rl) which is

substantially concentric, in plan view, to the arc of circumference Al.

In the exemplary embodiment considered, the centers of the arcs of circumference A1,A2 both belong to the axis of rotation AR but the arc of circumference A2 and its respective center lie on a plane that is different from, and parallel to, the plane upon which lies the arc of circumference Al and the respective center O - as will be understood shortly, this descends directly from the preferred embodiments discussed below (and in particular, by the implementation of the coupling means).

As better shown in Figure 3, in accordance with an embodiment of the present invention, the coupling portion 45i is comprised of a hollow cylindrical protrusion, which protrudes from the plate-like portion 20i of the link body 15i along the longitudinal direction X and has a through hole 50i which is suitable for receiving the pivot 45 along the transverse direction Y. Preferably, although not necessarily, the protrusion 45i is made from a plastic material, and even more preferably, as shown, it is made as one piece with the plate-like portion 20i (for example, by means of plastics injection molding techniques).

The coupling portion 452 is instead comprised of a pair of eyelets that project along the longitudinal direction X from the plate-like portion 202 (for example, as illustrated, from one of its central regions), and that are spaced apart along the transverse direction Y in such a way as to housing between them the protrusion 45i and the pivot 45 (so as to engage the link body 15i and the plate 2Ο2 by means of the pivot 45, as described shortly). Preferably, although not necessarily, the eyelets 452 are made from a plastic material, and even more preferably, as shown, they are made as one piece with the plate-shaped portion 202 (for example, by means of plastics injection molding techniques).

Advantageously, as illustrated, the protrusion 45i and the eyelets

452 of each link 15 have, along the vertical direction Z, an extension from the respective platelike portions 20ι, 2Ο2 such that, when the protrusion 45i and eyelets 452 are coaxially aligned and the pivot 45 is inserted between them, the upper surfaces of the plate-like portions 20ι, 2Ο2 are located substantially at the same level, thus both contributing to the formation of a portion of the resting surface As of the chain 10 which is substantially flat.

In the exemplary, but non-limiting embodiment illustrated in which the coupling portion 45i is comprised of a hollow cylindrical protrusion with a through hole 50i into which the pivot 45 is inserted, the region of support is located within the inner surface of the through hole 50i (preferably, in a part thereof). Therefore, in the embodiment considered, in order to obtain the relative movement between the link body 15i and the plate 152, the inner surface of the through hole 50i has, along the

longitudinal direction X, the region of support (with a profile the describes the arc of a circumference A2), and the pivot 45, which can move within the through hole 50i (at least) along the transverse direction Y, is firmly fixed between the eyelets 452 (in such a way as to be integral to the plate 152). In this way, in correspondence with a curve of the transport path, the pivot 45 (which has, in plan view, a substantially rectilinear shape), moving along the transverse direction Y and leaning in accordance with the magnitude of the curve, slides tangentially to the arc of circumference A2. This

determines, by construction, the movement of the plate 152 along the arc of circumference Al (see Figures 4A-4C). Therefore, in the embodiment described, the pivot 45 is housed within the through hole 50i with mechanical play along the longitudinal direction X.

Advantageously, the magnitude of such mechanical play is such as to render the movement of the plate 152 along the arc of a circumference Al efficient, but, at the same time, it is sufficiently low to avoid overlap between the link body 15i and plate 152 (a fact that, in the case of excessive mechanical play along the longitudinal direction X, may arise, for example, when, during installation, the chain 10 is operated manually by pushing rather than pulling). To achieve this, preferably, the through hole 50i has (along the longitudinal direction X) a substantially hourglass form, i.e. the inner surface therein comprises, in addition to the region of support (with a profile which describes the arc of circumference A2), a region of support (opposite, in the plan view under consideration) with a profile that is substantially complementary (in the following, the region of complementary support). Still more preferably, as shown, the region of support presents a profile that is substantially complementary to the cusp, with rectilinear portions having opposite inclinations with respect to an axis of symmetry S of the through hole 50i. This allows the pivot 45 to slide tangentially to the region of support without hindrance - in fact, as can be seen in Figures 4B and 4C, the region of complementary support, and the cusp shaped profile in particular, create local widenings that "assist" the inclination of the pivot 45 (and therefore the relative movement between the link body 15i and the plate 152) and that confer high mechanical stability to the chain 10 even within curves.

Therefore, when the chain 10 moves through a curve, the pivot 45, moving itself into the through hole 50i along the transverse direction Y and leaning itself onto the region of support (thanks to the mechanical play in the longitudinal direction X and the presence of the region of

complementary support) in such a way as to slide (and orientate itself) tangentially to the arc of circumference A2, determines the relative movement between the link body 15i and the plate 152 along the arc of circumference Al. The further transverse movement and the further inclination of the pivot 45 (and, therefore, the relative movement between the link body 15i and the plate 152) are arrested by the abutment of the terminal elements 352 against a portion of the side edge of the arched lip support element 30i (and/or, in accordance with embodiments of the present invention, by the abutment of the pivot 45 against the region of

complementary support).

As shown in Figures 5A-5C, the coupling means in a particular embodiment of the link according to the present invention may comprise a roller 45 as the coupling element and an eyelet 45i as the coupling portion of the first link element. The eyelet has an inner surface that defines a through hole 50i for receiving the roller therein in rolling manner. By providing the coupling element, i.e. pivot, as a roller a normal sliding friction between the coupling element and the eyelet is replaced by a rolling friction between the roller and the eyelet, thus resulting in less wear and prolonging the service life of the link. The coupling means further comprise, between the inner surface of the eyelet and the roller, an intermediate connecting element 60, characterized by a concave engagement surface which is adapted for fittingly engaging with a convex surface of the roller. As such the intermediate connecting element forms a bearing surface with a contact surface between the roller and the intermediate coupling member being relatively large, improving a distribution of the pressure applied on the roller during use of the link in a chain. The intermediate connecting element can be formed with the eyelet out of one piece, or it can be integrally coupled with the eyelet or it may be a separate component. The intermediate connecting element is formed such as a bearing means that sliding movement of the roller within the through hole allows for the movement of the first link element and the second link element with respect to each other. The freedom of movement of the roller is demonstrated by the different position of the roller in Figure 5B and in Figure 5C. The intermediate connecting element can be a replaceable or exchangeable part so that any wear inside the coupling means affecting the intermediate coupling means may be remedied by replacing the relatively simple intermediate coupling means. The intermediate connecting element may comprise or consist of a solid body constructed from wear-resistant material, such as for example be made of plastic or metal. The body may comprise on one side a groove or incision, which defines the concave surface that is complementary to the convex surface of the roller. In particular, the intermediate connecting element may comprise or consist of a shaped body in the form of a meniscus. As can be better appreciated from Figures 2A-2B and 3, and as previously mentioned, each link body 15i comprises an additional coupling portion 55i, which is also configured in such a way as to engage the pivot 45 in order to couple in an articulated manner each link 15 to an adjacent link (for example, the successive one) in the sequence.

In accordance with the illustrated embodiment, this coupling portion 55i comprises a recess in the plate-like portion 20i (for example, C- shaped) which extends, along the longitudinal direction X, from one side of the plate-like portion 20i opposite the arched side 25i, and, along the vertical direction Z, at least until the protrusion 45i (or beyond it, as illustrated by way of example), in order to form a forked portion.

Advantageously, the forked portion 55i is dimensioned in such a way as to housing the protrusion 45i and eyelets 452 of the next link in the sequence, and presents, in correspondence with its opposite side walls, a pair of through holes 60i which are suitable for receiving the pivot 45 along the transverse direction Y. In this way, the pivot 45 that engages the link body 15i and the plate 152 of the same link 15 is also used to couple each link 15 to the adjacent link in the sequence. The arrangement of the pivot 45 along the transverse direction Y also allows adjacent links 15 to be coupled in an articulated manner, i.e. in such a way as to confer to the chain 10 the possibility of arching itself. In fact, each pair of links 15 can move around the respective pivot 45 thereby ensuring the arching of the chain 10 around the transverse direction Y.

Preferably, although not necessarily, the forked portion 55i is made from a plastic material, and even more preferably it is formed as one piece with the plate-shaped portion 20i and/or with the protrusion 45i (for example, by means of plastics injection molding techniques).

Thanks to the present invention, the interval that can be obtained between adjacent links 15 in the chain 10, defined, for example, as the distance along the longitudinal direction X between adjacent pivots 45 (Figure 3), is reduced in comparison to known zero-gap chains. In fact, while known zero-gap chains provide coupling means that, intercepting the axis of relative rotation defined by themselves, have necessarily significant dimensions (thus determining an excessive length of link along the longitudinal direction X), the chain 10 in accordance with the present invention provides, in contrast, coupling means which, in not intercepting the axis of rotation AR (being that is decentralized compared to it, see

Figures 4A-4C) can be constructed with reduced dimensions (and in particular with a greater width and a decreased length interval).

Thanks to the reduced interval, the chain 10 in accordance with the present invention has reduced minimum radii, high movement fluidity, a smaller footprint when it is curved around the pinion, and is suitable for replacing traditional chains currently installed in many conveyors.

Moreover, in spite of some known zero-gap chains (typically characterized by structures of a lower density material in order to derive the hinging), the proposed chain 10 has high qualities of compactness and solidity (in fact, in accordance with the present invention, the coupling between the link body 15i and plate 152 and between adjacent links 15 is obtained by means of a single pivot 45 and a single hinging). This results in a chain 10 with high resistance to stress (e.g. tensile strength), and therefore with greater usage reliability.

Of course, in order to satisfy contingent and specific requirements, a person skilled in the art may bring to the solution described above many modifications and logical and/or physical variations. More specifically, although this solution may have been described with a certain level of detail with reference to one or more embodiments thereof, it is clear that various omissions, substitutions and changes to the form and details as well as other embodiments are possible. In particular, various embodiments of the invention can be put into practice even without the specific details (such as the numerical examples) set forth in the preceding description in order to provide a more complete understanding of them; on the contrary, well- known features may be omitted or simplified in order not to obscure the description with unnecessary details. Moreover, it is expressly intended that specific elements described in relation to each embodiment of the solution exposed may be incorporated into any other embodiment in the form of a normal design choice.

Similar considerations apply if the link 15 has a different structure or comprises equivalent components. In any case, any component can be separated into further elements, or two or more components may be combined into a single element; in addition, each component may be replicated in order to support the parallel execution of the corresponding operations. It is also to be pointed out that (unless specified otherwise) any interaction between different components does not generally need to be continuous, and may be direct or indirect by means of one or more

intermediaries.

For example, although in the present description explicit reference is made to plastic and/or metal pivots 45 and to plastic link bodies 15i and plates 152, nothing excludes the consideration of other materials for specific applications (for example, in accordance with the stresses to which they are subjected in such applications). In this respect, the pivots 45, the link bodies 15i and/or the plates 152 can be constructed from thermoplastic resins reinforced with synthetic (e.g. Kevlar®) or mineral (e.g. glass fiber) fibers.

In addition, although the description has made explicit reference to a link body 15i having a plate-shaped portion 20i, arched lip support item 30i, protrusion 45i and forked portion 55i constructed in a monolithic manner, and a plate 152 having a plate-like portion 202, arched slot 302, end stop elements 352 and eyelets 452 constructed in a monolithic manner, this is not to be understood in a limited manner - in fact, similar considerations also apply in the event that (at least some of) these elements are constructed separately (even in different materials) and fixed together at a later stage.

In addition, although the description has made explicit reference to a curved contact region 402 (defined by the curved slot 302 and end stop elements 352 in correspondence with the arched side 252 of the plate-like portion 2Ο2) which is suitable for being supported by the arched lip support element 30i of the plate-like portion 20i and to slide along it in order to allow for relative movement between the link body 15i and the plate 152, this partial overlap between the link body 15i and the plate 152 is not to be understood in a hmiting manner. In fact, in alternative embodiments of the present invention, not shown, the link body 15i and the plate 152 can be shaped and sized in such a way as to be side by side (rather than stacked) during the relative rotation - for example, with portions of the edge reciprocally facing the link body 15i and the plate 152 which can be spaced apart by a gap (arched) of a dimension that is appropriately reduced.

Finally, although the description has made explicit reference to the mechanical play between the protrusion 451 and the pivot 45 obtained by means of a straight profile of the supportive region of the pivot 45 and the arched profile of the supportive region of the protrusion 45i (i.e. the inner surface of its through hole 50i), further implementations are possible in which, in addition to or as an alternative, the supportive region of the pivot 45 has a convex profile (for example, arched).

Claims

1. Link (15) for article conveyor chain (10), the chain (10) comprising a sequence of links (15),

said link (15) that is suitable for being coupled in an articulated manner to at least one adjacent link in the sequence in order to allow for arching of the chain (10),

said link (15) defining a respective portion of a resting surface (As) for articles to be transported, and

said link (15) comprising a first (15i) and a second (152) link element, and coupling means (25i,30i,45i-55i;252-452;45) for coupling to each other the first (15i) and second (152) link elements, characterized in that

said coupling means (25i,30i,45i-55i;252-452;45) comprise:

a coupling portion (45i,50i) of the first link element (15i), a coupling portion (452) of the second link element (152), and a coupling element (45) that is suitable for engaging itself with the coupling portion

(45i,50i) of the first link element (15i) and with the coupling portion (452) of the second link element (152), a mechanic play being provided between the coupling portion (45i,50i) of the first link element (15i) and the coupling element (45) allowing for relative movement of the first link element (15i) and the second link element (152) on a plane that is parallel to said respective portion of the resting surface (As), and

a further coupling portion (55i) of the first link element (15i), the coupling element (45) being suitable for engaging in said further coupling portion (55i) in order to couple said link (15) in an articulated manner to an adjacent link in the sequence thus allowing for said arching of the chain (10).

2. Link (15) according to Claim 1, wherein the coupling portion

(45i,50i) of the first link element (15i) and the coupling element (45) comprise respective regions of support at which there is the support between the coupling portion (45i,50i) of the first link element (15i) and the coupling element (45) during said relative movement, at least one between the region of support of the coupling portion (45i,50i) of the first link element (15i) and the region of support of the coupling element (45) having a convex profile that permits said mechanical play.

3. Link (15) according to Claim 2, wherein said coupling means

(25i,30i,45i-55i;252-452;45) allow the first link element (15i) to move with respect to the second link element (152) along a first arc of circumference (Al) laying on said plane, wherein the region of support of the coupling element (45) has a straight profile, and the region of support of the coupling portion (45i,50i) of the first link element (15i) has an arched profile which describes a second arc of circumference (A2) which is substantially concentric, in plan view, to the first arc of a circumference (Al).

4. Link (15) according to Claim 3, wherein said means of coupling (25i,30i,45i-55i;252-452;45) allow the first link element (15i) to move with respect to the second link element (152) along said first arc of a

circumference (Al) around an axis (AR) that is perpendicular to said respective portion of the resting surface (As), the coupling means

(25i,30i,45i-55i;252-452;45) being spaced apart from, and not intersecting, said axis (AR).

5. Link (15) in accordance with any of the preceding Claims, wherein the coupling element (45) of the coupling means (25i,30i,45i-55i;252-452;45) comprises a roller, while the coupling portion (45i,50i) of the first link element comprises an eyelet (45i) with an inner surface that determines a through hole (50i), enabling the roller to be received therein in rolling manner.

6. Link (15) according to Claim 5, wherein the coupling means

(25i,30i,45i-55i;252-452;45) also comprise an intermediate connecting element between the inner surface of the first link element and the roller (45); the intermediate connecting element having a concave engagement surface that is adapted for fittingly engaging with a convex surface of the roller.

7. Link (15) in accordance with any of the preceding Claims, wherein:

the first link element (15i) comprises a plate-shaped portion (20i) having an arched-lip support element (30i), and the second link element (152) comprises a plate-shaped portion (2Ο2) having an arched region of contact (4Ο2) that is suitable for being supported by the arched-lip support element (30i) and designed to move by sliding along it, and wherein

the coupling portion (45i,50i) of the first link element (15i) comprises a protrusion (45i) extending along a first direction (X) parallel to said plane and having a through hole (501) which is suitable for receiving the coupling element (45) along a second direction (Y) that is orthogonal to the first direction (X).

8. Link (15) according to Claim 7 when directly or indirectly dependent upon Claim 2, wherein the region of support of the coupling portion (45i,50i) of the first link element (15i) is located on an inner surface of the through hole (50i).

9. Link (15) according to Claim 8, wherein said through hole (50i) has, along said second direction (Y), a substantially hourglass form, the inner surface of the through hole (50i) comprising a further region of support with a profile that is substantially complementary with respect to the region of support.

10. Link (15) according to Claim 9, wherein said substantially complementary profile comprises a cusp profile.

11. Link (15) in accordance with any of Claims from 7 to 10, wherein the arched contact region (4Ο2) comprises end stop elements (352) for limiting said relative movement.

12. Link (15) according to any of Claims from 7 to 11, wherein the coupling portion (452) of the second link element (152) comprises a pair of eyelets (452) extending from the respective plate-shaped portion (2Ο2) and suitable for housing between them the coupling portion (45i) of the first link element (15i), the coupling element (45) being engaged with said pair of eyelets (452).

13. A chain (10) for the transportation of articles, said chain (10) comprising a sequence of links (15) in accordance with any of the preceding Claims.