Traditionally, product conveyor belts for transportation of products in an industrial environment utilised a single plastic or nylon woven belt providing a continuous loop extending around a series of guide wheels. Whilst such belts provided the advantage of flexibility around such guide wheels, their strength was limited and they required sufficient tensioning in the belt to maintain a rigid surface to transport goods mounted thereon. Developments in conveyor belt systems have now resulted in the design of modern continuous loop belts consisting of a plurality of moulded plastic link elements connected together so as to provide a continuous chain. Such link elements are conventionally provided with a flat upper surface which the products to be transported are able to sit when the belt travels around a predefined path.

Belts formed from such a plurality of chain link elements which offer considerable advantages over the previously used nylon woven belts by providing additional rigidity, are easily manufactured by simply adding or removing the appropriate number of link elements and also provide for ease of maintenance since any

stretching during any operation of such belts can be compensated for by removal of sufficient link elements to retighten the belt.

However, conventional link elements are provided with a substantially flat upper product carrying surface to provide an appropriate platform onto the products which are supported when the belt extends around a substantially horizontal product carrying path. Where such belts carry mass product such as stacked elongate rods within the cigarette manufacturing industry, then the transfer of such carpet of rods from a traditional nylon woven belt system is effected by passing the nylon belt around a vertically disposed idler wheel (rotating about a horizontal axis) with the belt conforming to the radius of such wheel and an external scraper then being disposed tangentially to the belt as it is passed over the idler wheel to deflect product off the now curved woven belt onto an appropriate product removal path or equipment. However, when such modern link element belts pass over vertically disposed idler wheels, each flat product conveying surface is disposed tangentially to the radius of curvature of the wheel preventing use of such scraper elements which would catastrophically engage with the edges of each link element. This has necessitated the development of alternative means of removing such mass flow product from conveyor belt systems since it is more difficult to deflect effectively such product from the conveyor belt. Attempts have been employed to overcome this problem by the provision of side deflector plates for engaging overhanging portions of the product which project beyond the side edges of the belt. However, such arrangements are usually quite complex and also

expose the products to additional stresses where it overhangs the belt and, since such product overhangs the belt, it is more prone to outside influences and damage. Alternatively, the products have to be removed whilst the belt is maintained in a flat configuration which decreases the effective capacity of any reservoir utilising such conveyor belt systems.

Conventional conveyor belts for transporting a carpet of stacked rod-like products (such as cigarettes) are required to be able to effectively follow a path around a substantially vertical axis whilst remaining in a horizontal plane. In these instances where the curved portions of the belt meet with straight runs of the belt a deflector plate is located adjacent one or both sides of the belt in order to stop the carpet of rods from falling off the belt. These plates often cause damage to the ends of the rods.

A carpet of rods such as cigarettes or filters, tend to nestle with each row nesting in the recesses formed by two rods of a lower row of the rods. A considerable force is required to be exerted by the deflector plates in order to push the whole carpet radially inwards so that they remain on the curved sections of the belts.

This causes even more damage to the ends of the rods.

It is therefore an object of the present invention to provide a chain link element for a product transportation belt which alleviates the aforementioned problems in a

cost effective and efficient manner and to also provide a continuous product transportation belt comprising such improved link element.

A further object of the present invention is to provide a chain link element that allows the belt to follow a curved path about axes that can be angled to each other.

A further object of the present invention is to provide a chain link element that assists in aligning rod like products to align themselves substantially radially when the belt on which they are carried follows a substantially horizontal curved path about a vertical axis.

According to one aspect of the present invention there is provided a chain link element for a product transportation belt, the element comprising a product carrying surface having a front end, an opposed rear end, two opposed side edges each extending between said front and rear ends and a connection means for allowing flexible connection of the element to an adjacent similar element such that the front end of the element is proximate to the rear end of the adjacent element, characterised in that said product carrying surface has a convex profile extending between said front end and said rear end and having at least one elongate projection on the product carrying surface that extends in a direction towards the side edges of the element.

Preferably, a radius of curvature of said convex profile is predetermined such that in use, when the belt passes around a rotatable support means the radius of curvature of the product carrying surface of each link element is substantially co- axial with an axis of rotation of the support means. In this manner, as a plurality of link elements forming a conveyor chain pass over an appropriate support wheel the convex curvature of such outer surface of adjacent link element form a uniform convex circular surface following the external circumference of such wheel presenting a substantially smooth curved external surface of such belt mimicking the smooth curved surface of traditional nylon woven belts and allowing product mounted on the belt to be readily removed by appropriate deflector plates in close tangential proximity to such uniform curved surface.

Preferably, the height of the elongate projection relative to said product carrying surface decreases towards at least one of said side edges so as to provide a tapered projection. Usually, such link elements will comprise at least two inclined elongate projections, a first elongate projection tapering towards a first side edge and a second elongate projection tapering towards a second side edge. Such tapered or inclined projections serve as a deflecting means to deflect any rogue product on a conveyor belt in a non-desired position to roll off and fall off a conveyor belt formed of such link elements. The elongate projections may also comprise two or more spaced portions extending along a common axis.

Preferably, the front and rear ends are of complementary shape and together with the connection means are shaped and dimensioned so as to permit relative restricted movement between the front and rear ends of other adjacent elements.

More specifically, the front and rear ends together with the connection means may be shaped and dimensioned to allow pivotal movement about an axis extending in a direction substantially between the side edges of an element. Alternatively, or in supplement, the front and rear ends together with the connection means are shaped and dimensioned to allow rotation of elements about an axis substantially orthogonal to a plane that contains a first axis extending in a direction between the front and rear ends and a second axis extending in a direction between the side edges of an element and thereby allow the elements to follow a curved path in said plane.

Further, according to the present invention there is also provided a plurality of chain link elements connected together with the front edge of each element connected to a rear edge of an adjoining element thereby to define an endless product transportation belt. Usually, in use, the belt is designed to pass around a rotatable support means and wherein the radius of curvature of each link element is predetermined so as to be co-axial with an axis of rotation of the support means when each link element passes around the support means during a change of direction of said belt.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying illustrative drawings in which: Figure 1 is a front elevation of a chain link element according to the present invention; and Figure 2 is a plan view from above of the chain link element of Figure 1; and Figure 3 is a side view of the chain link element of Figure 1 ; and Figure 4 is a front perspective view of a product transportation belt comprising an array of chain link elements of Figure 1 in a partially curved configuration; and Figure 5 is a perspective view of the transportation belt of Figure 4 in a substantially flat configuration; and Figure 6 is a side view of a part section of a transportation belt of Figure 4 passing about a support wheel; and Figure 7 is a cross sectional view of a conventional chain support wheel.

Modern transportation belts, usually formed as a continuous belt (or closed loop), are produced from a plurality of individual chain link elements (10) as shown in Figures 1 to 3. Each link element comprises an upper support or product carrying surface (12) extending between a front end (14) and rear end (16) thereof. This surface (12) is then provided with two opposed side edges (18) and (20) (here substantially parallel) extending between said front end (14) and rear end (16).

Extending from the underside (22) of such support surface (12) is a connection means (24) which permits similar link elements to be joined together so as to form an elongate chain (as shown in Figures 4 and 5).

Furthermore, as seen in Figure 2 the front end (14) of the surface (12) is provided with a substantially rectangular rebate (26) whereby the rear end (16) is provided with a substantially rectangular projection (28) of complementary shape. As can be seen from Figures 4 and 5 similar link elements (10) and (10') are connected together so that the front end (14) of a first link element (10) is proximate to the rear end (16) of a similar adjacent link element (10'), whereby the rectangular projection (28') of said similar link element (10') is received within the corresponding rectangular rebate (26) of the first link element (10). In this way the link elements are connected together so that the front end of a first link element is maintained proximate to the rear end of the adjacent link element.

There is limited freedom of movement between adjacent links (10) to allow the conveyor belt to be able to follow a curved path whilst remaining in a horizontal plane. In other words the front and rear ends are shaped and dimensioned to allow

rotation of elements (10) about an axis substantially orthogonal to a plane that contains a first axis extending in a direction between the front and rear ends and a second axis extending in a direction between the side edges of an element and thereby allow the elements to follow a curved path in said plane.

The connection means (24), as illustrated in Figures 1 to 3, comprises a first connection member (30) associated with the front end (14) of the link element and a second connection member (32) associated with the rear end (16) of such link element. The first connection member (30) comprises two substantially parallel sidewalls (34) extending downwardly from the underside (22) of the support surface (12) (these walls are shown in hashed lines in Figure 2 and lie immediately adjacent to the rectangular rebate (26) as shown).

Similarly, the second connection member (32) also comprises two parallel sidewalls (36), again extending downwardly from the underside (22) of the support surface (12) and again shown in hashed lines in Figure 2 so as to lie immediately adjacent to the outer side edges of the rectangular projection (28). In this manner, it is appreciated that when two similar link elements (10) and (10') are positioned as shown in Figure 4, the two parallel sidewalls (36) of the second connection member (32) are received in parallel between the two parallel sidewalls (34) of the first connection member of an adjacent link element (10). As now seen in Figure 3 each of the two parallel sidewalls (36) of the second connection member (32) have a first elongate aperture (38) extending

therethrough whereby each of the two parallel sidewalls (34) of the first connection means are further provided with a substantially cylindrical hole (40) passing therethrough.

Referring now specifically to Figure 6 the cylindrical hole of wall (34) has a partially flattened side edge (42) for complementary frictional engagement with an appropriate elongate rod of similar cross sectional profile. As can be seen from Figure 6 that when two adjacent link elements (10) and (10') are aligned, an appropriate elongate rod of complementary cross sectional profile (not shown) is inserted to extend between the two parallel apertures (40) of the parallel sidewalls (34) of the first link element (10) and also pass through the two parallel elongate holes (38') of the parallel sidewalls (32') of the second link element (10'). Such elongate member is frictionally engaged with the holes (40) so as to restrain its displacement therefrom and is prevented from rotation within this hole due to the asymmetrical nature of the cross section thereof. However, it will be appreciated that the elongate holes (38') of the parallel sidewalls (32') of the second connection member allows a certain degree of play or relative displacement of the second link element (10') about such elongate rod. This permits for flexible connection of two adjacent link elements in a conventional manner. A chain formed from a plurality of such link elements (10) is now shown in Figures 4 through 6.

As can also be seen in Figures 1 and 3 each link element (10) is further provided with a pair of substantially flat feet members (44) extending transversely from the parallel sidewalls (34) so as to extend parallel with the underside (22) of the support surface (12). In this respect such a link element (10) is of conventional design as is a chain formed from a plurality of connected link elements.

Referring now to Figure 6 and Figure 7 a chain (100) formed from a plurality of link elements is intended to carry product in a substantially horizontal plane to a position where it is to be divested from the conveyor to an appropriate workstation. The chain (100) will then be fed around an appropriate vertically disposed wheel member that rotated about a substantially horizontal axis (either an idler wheel or a powered wheel) to return to a further input workstation where a new product is then picked up. A conventional design of idler wheel (80) is illustrated in cross section in Figure 7 and comprises a substantially solid cylindrical central body portion (82) disposed about an axis A and having a pair of parallel and radially extending sidewalls (84) extending therefrom to provide a circumferential and radially extending channel (86) of substantially rectangular cross sectional profile as seen in Figure 7. This channel (86) has an inner cylindrical surface (88). The chain (100) will pass about such idler wheel as shown schematically in Figure 6 whereby the feet (44) of each link element (10) will effectively sit upon the inner cylindrical surface (88) of the radial channel (86) as the chain passes thereabouts (alternatively or in combination with support of such feet the underside (22) of the support surface (12) may be supported by the

outer edges of the sidewalls (84) ). It is to be appreciated that the wheel (80) is only shown schematically and in hashed lines in Figure 6 for clarity whereby the outer walls (84) are omitted for clarity. The idler wheel (80) is designed so that the distance between the sidewalls (84) is sufficient to permit both feet member (44) of each link element to sit within the channel (86) whereby the distance between such parallel sidewalls (84) is no greater than the maximum width of each link element so that the underside (22) of the support surface (12) is then able to sit on the periphery of each wall member (84) as is conventional. In this way, the idler wheel (80) serves as a guide mechanism for maintaining correct alignment of the belt as it passes thereabouts. If appropriate, such idler wheel could be replaced by a drive wheel having appropriate means for engaging with each link element to effect a motive force thereto to move such belt.

In the present embodiment, the belt (100) formed from the link elements (10) is primarily intended to carry rod like articles such as cigarettes or cigarette filters (102) along straight and curved paths whilst remaining substantially horizontal.

Such product (102) will normally form a carpet of products several centimetres thick (up to 20cm) to be transported thereby, whereby such product carpet will be removed from the conveyor belt (100) as it passes about the idler wheel (80).

The present invention resides in the modification of such link elements (10) to provide an improved configuration of chain link element which provides for enhanced removal of the product (102) from a chain (100) formed therefrom.

Referring to Figure 3 the upper (or outermost) product carrying surface (12) is varied from conventional link element designs (which are traditionally flat) by being provided with a convex profile extending between the front end (14) and rear end (16) thereof. With reference to Figure 6, the radius of curvature of this convex profile is predetermined so that the support surface (12) is substantially coaxial with the axis A of the idler wheel (80) about which it passes so that, as seen in Figure 6, the support surface of the chain (100) (provided by the plurality of link elements (10) ) forms a substantially smooth curved surface about such idler wheel. By providing such a smooth curved surface of the chain (100) about the idler wheel an appropriate product removal tool (110) (Figures 4 and 6) can be employed for appropriate removal of the product (102) from such conveyor belt.

This product removal tool (110) is provided with a complementary lower curved surface (112) having a curvature complementary to the radius of curvature about axis A so as to closely overly the smooth curved surface of the conveyor belt (100) about such idler wheel (80). By permitting such tool to overly the conveyor belt (100) in such close proximity causes the product carpet (102) to be readily deflected from the conveyor belt (100) on to the deflector plate (110) without damaging the product.

The link elements (10) of the present embodiment are also provided with a series of two cleats (120), whose function will be described below but which serve to provide a discontinuity on the smooth curved surface of the belt (100),

necessitating that the product removal tool (110) be aligned with such cleats (120) so as to prevent catastrophic engagement with such cleats. This necessitates that the product removal tool (110) is only able to be disposed in close proximity with the belt (100) through a central channel portion (122) extending between adjacently cleats (120) on each link element, therefore necessitating that the product removal tool (110) is provided with a tongue (124) for this purpose.

However, it is to be appreciated that such cleats (120) are optional whereby the product removal tool (110) could be placed in close proximity with a belt across the complete width of each link element if so required and where no cleats are employed.

The current product transportation belt (100) is designed for specific use within the cigarette manufacturing industry for transportation of rod like articles, whereby such rod like articles are stacked in a carpet of up to 20cm deep. If such carpet was formed on a purely flat surface then it would settle into a compact honeycombed mass restricting flexibility of the carpet should the belt be required to pass around a curved path whilst remaining in a horizontal plane. It is therefore recognised within this specific industry that the carpet can be disrupted by the provision of a series of cleats (120) or projections on the support surface (12) of each link element to disrupt alignment of the plurality of rod like articles within the carpet, making such carpet less compact and more susceptible to displacement and manoeuvrability as the belt itself passes around appropriate curved path in a horizontal plane. The use of such cleats (120) is further enhanced in the present

invention by the convex profile of each link element (10), which also provides a disruption to the alignment of the carpet by providing a series of troughs (130) and ridges (132) of the belt (100). Thus, a second advantage is demonstrated through the use and employment of a convex outer surface of such chain link elements.

Still further, whilst traditional cleats simply comprise hemispherical projections extending out of the flat surface of such link elements, the current embodiment provides for an improved link element cleat (120). In conventional link element design, it is usual to utilise a single hemispherical cleat extending partway across the width of such link element. However, in the present invention the cleat (120) is divided into two equal portions (120) disposed about a central channel portion (122). As previously discussed, the central channel portion (122) permits the product removal tool (110) to be positioned in close proximity to the convex support surface (12) as it passes about the idler wheel (80). Secondly, the cleat design is modified over a conventional design by being provided with outer tapered portions (121). In this manner each cleat (120) comprises an inner hemispherical projection (119) of uniform height above the support surface (12) and an outer tapered portion (121) which reduces in height above the support surface (12) towards the outer edges (18, 20) of each link element (10) (Figure 1).

The reason for the use of such tapered outer portions (121) of the cleats will be understood with reference to Figure 2. Here, a conventional rod like article (for example a cigarette) is shown by reference numeral (200) in hashed lines. Such

rod like article (200) does not extend the complete width of the link element (10) and is disposed substantially equidistant from each of the side edges (18,20) so as to maintain the carpet of product carried by conveyor (100) remote from the edges to prevent damage to individual articles within that carpet. The purpose of the cleats, as previously described, is to maintain a less compact carpet to allow flexibility. However, a recognised problem of transporting carpets of rod like articles of this type is that occasionally one or more of the rod like articles (200) may become displaced from the carpet and will fall off the conveyor belt (100).

Normally this does not present a problem as the articles will become dislodged during loading of the carpet onto the conveyor belt at an initial position, whereby fallen product at this position will not create any difficulty or effect operation of the conveyor equipment. However, occasionally such rod like articles when displaced from the carpet will fall onto the edge of the conveyor (between the <BR> <BR> edge of the carpet and the side edges (18 or 20) ) of each link element and remain there so as to be transported by the conveyor (100). This can cause such rogue rod like articles to be transported to a position within the conveyor system whereby their inadvertent falling from the conveyor belt (100) could be more problematic and cause jamming damage to machinery. For this reason, the specific design of cleats shown in the figures and having a tapered outer portion (121) causes immediate deflection of any rod like articles which fall from the carpet onto such outer portions of the tapered cleats (121) causing them to be immediately deflected off the conveyor belt at a position where they are unlikely to cause damage to the machinery. Thus, the enhanced cleat design (120) having tapered

outer portions (121) serve to prevent rogue or displaced rod like articles remaining in an undesired position on the conveyor belt.

It is to be appreciated that the invention is not limited to the specific configuration of this improved cleat design shown in the current embodiment and that such cleat design (120) could be tapered along its entire length as opposed to partly incorporating a uniform hemispherical portion (119) remote from the edges.

Secondly, the use of such an improved cleat design is not limited to the specific embodiment of a link element having a convex outer surface but is equally applicable to link elements having a flat support surfaces. In addition, each link element may be only provided with one cleat member (120) which cleat member may be tapered along its entire length. Furthermore, each link element may be provided with more than two cleat members (120) if appropriate.