Patent Description:
In the art, conveyors are frequently used for transportation of bottles, cans, various kinds of good, such as edible products, potable products and or other goods. When the tracks or chains of these conveyors are moved through a bend, the pitch of the individual links is greater at the outer circumference of the bend and smaller at the inner circumference of the bend.

Thus, with conveyors in the art, at relative tight curves or curves with a limited radius, the individual links may open-up at the outer side of the track curve while similarly get maximally compressed and nested at the inner side of the track curve. Thus below a specific radius, ordinary conveyor chains are not suitable for being guided through the curve.

Here dedicated curved tracks are used, equipped with dedicated chain links that are typically wedged shaped, where the outer lateral side of the conveyor chain comprises the wider portions of the individual links and the inner lateral side of the conveyor chain comprises the smaller width portions of the individual links.

Thus, this dedicated conveyor chain can only move in the bend, and is not suited to move through straight parts of the conveying system. As a consequence, the curved section of this conveyor comprises a return part, moving below the transport part of the conveyor chain. At both transport ends, i.e. at the intake and/or the offload end of the conveyor track conical members such as a conical return idler or a conical drive is arranged. Alternatively, a set of fixed return guiders can be arranged around which the conveyor chain can be guided.

Thus, the transport part and the return part are moving along a similar track, being held in place amongst others by two conical members or a set of return guiders.

A serious draw back of these chains is that when broader chains are needed, the width of the individual chain links at the outer curve side of the chain tend to get relative large, resulting in a bumpy, ratcheting unsmooth transfer, a phenomenon also known as the polygon effect. Furthermore, the wider the chain links, the larger the diameter of the conical members or guiders at both the intake and offload side of the chain need to be, in order to guide the chain. A larger diameter of the conical members or of the return guiders leads to a larger gap between the corresponding feed in and offtake conveyors.

The rotating axis of the conical member needs to be pointing towards the centre point of radius of the curve in order to have a smooth motion of the conveyor belt. Yet when broad conveyor chains are used, the outer side of the conical member needs a larger diameter and thus more space at the outside of the bend than at the inside, such that gaps between feed in and offtake conveyors is wedge shaped. This effect also limits the width of the conveyor belt.

A last effect that limits the width of the conveyor belt is the relative large width of the links at the outer side of the curve, leading to unsmooth, ratcheting or bumpy transferral of goods at the outer side of the curve, an effect known as polygon effect.

Thus, these conveyors are only practical below a maximal conveyor track width. As a result, these conveyors can be a limiting factor in the output volume of a production line in which these conveyors are applied.

The <CIT> discloses corner conveyor enabling the transportation of articles like newspapers to be around a corner from one horizontal assembled belt to another. The products are forwarded by a plurality of linear narrow belts (<NUM>) to be deposited on several chains (<NUM>) that move with different speeds in concentric grooves (<NUM>). The chains protrude above concentric oriented bent strips between which strips the concentric grooves are allocated. An outer chain travels with a higher speed than the a chain adjacent inwardly thereof to carry the articles smoothly and evenly around the corner.

The French patent application <CIT> discloses a conveyor belt curve with two conical return rollers. With the solution proposed in this document, the disadvantageous effects as described herein above occur as well. The return rollers become relative large in diameter at the outside of the curve, Thus, the polygon effect is occurring on the outside of the bend and the relative large openings between the individual links at the outer radius of the support surface are posing problems as well. This exact solution is limited in its operational width because of these effects.

Accordingly, it is an object of the invention to mitigate or solve the above described and/or other problems of conveyors chains in the art, while maintaining and/or improving the advantages thereof.

More specifically the object of the invention can be seen in providing a curved conveyor chain that is more practical in use, of which the gaps at intake and offload ends of the conveyor can remain relatively small, while the transporting width can be relatively wide and potentially be extended.

These and/or other objects are reached by a transport conveyor curve according to claim <NUM>.

This substantially equal contact angle of movement of the tracks with the rotating axis of the conical drive is configured in order to have the individual tracks move with a corresponding angular speed through the curve. Thus, any product transported on the conveyor curve will experience a smooth transport, where speed differences between the separate individual conveyor tracks is reduced or absent. In this way products experience limited forces induced by the individual conveyor tracks moving relative to each other.

The separate parallel tracks comprise wedge-shaped links, wherein the angle of the wedge of the wedge-shaped links is smaller of an outer track, when compared with the angle of the wedge of the wedge-shaped link of a more inner track. By the reduced angle, the pitch or the width of the links at the curve outside is reduced as well, such that the polygon effect is reduced leading to a smoother, less rattling transfer can be obtained. The conical drive can be arranged in a return part of the conveyor track. If the conical drive is arranged in the return part, below the transport surface, the separate individual tracks can have a corresponding angular velocity in the track, without the wide gap, which usually exists with a conical drive installed at one of the transfer sides of the conveyor, i.e. at the intake or the offload side.

The conical drive is a conical drum or a series of drive gears or sprockets with a, towards the direction of the outside ascending diameter. In case the conveyor track is a continuous belt, a drum would make a better frictional transfer of motion than a set of sprocket wheels. In case of a chain link conveyor, a series of sprocket wheels would give a better transfer of motion.

The drive gears or sprockets have an increasing diameter and/or number of teeth towards the outside of the curve. Since the links of the individual separate conveyor tracks have different pitch angles relative to the pitch angles of the links of the other separate conveyor tracks, the number of teeth on the sets of sprocket wheels need to be adapted as well. Thus, the outer sets of sprocket wheels, on the curve outside typically have more teeth than the sets of sprocket wheels on the inside. By the different diameter and number of teeth, the individual conveyor tracks move in a substantially corresponding angular velocity through the curve. The returns of the conveyor comprise a series of idlers, wherein each parallel track comprises its own set of idlers. The distance in vertical direction of each set of idlers increases towards the outside of the curve in order to compensate for the differences in path length of the individual conveyor tracks. Thus, the diameter of the idlers towards the curve outside can be of comparable diameter resulting in that the transfer of the conveyor can approximate a cylindrical transfer.

Alternatively, the returns can comprise a series of guiders, wherein the guiders can comprise two rounded edges. The rounded edges are placed one above the other, and can guide the individual tracks around a first rounded edge from a laying plane, in a direction downward, and around a second rounded edge again in a laying plane, moving back in opposite direction. The distance between the rounded edges from each guider increases towards the outside of the curve, in order to compensate for the differences in path length of the individual conveyor tracks. By means of the idler sets or the guiders, arranged as indicated, the wedge-shaped gap at the intake and offload ends of the transport track can elegantly be reduced, without sacrificing transporting width of the conveyor. Thus, both a smoother transfer and a reduced gap width can be obtained, while the width of the conveyor, and thus its conveying capacity can be extended.

The idlers or guiders of the individual conveyor tracks are configured to run independently from the idlers of the other conveyor tracks. Since the angular speed of the separate tracks is the same, and the length of the individual tracks is larger towards the curve outside, the idlers each rotate in a different rotation velocity. The individual links of the chain can comprise two sets of hinging pin engaging elements, one set being configured for engaging a leading side hinging pin and one set being configured for engaging a trailing side hinging pin, wherein the two sets of hinging pin engaging elements are connected to a support structure, and wherein the support structure extends on a first side, e.g. a transport surface side relative to the hinging pin engaging elements and the support structure does not extend beyond the hinging pin engaging elements on a second side.

By this arrangement, the hinging pins, when inserted and keeping together two consecutive links, can at sections in between the hinging pin engaging elements, move and be guided, supported and/or borne by guiders, or guiding surfaces. Thus, the tracks of the transport conveyor can guide smoothly, supported on the hinging pins. This is advantageous, in that the hinging pins have a relative low friction contact surface with the guiders or guiding surfaces, mainly due to their relative small diameter. Thus, the total friction will be relative low, such that less friction losses may occur and less drive power may be needed. Furthermore, wear of the links and the support structure and the guiding surfaces or guiders may be reduced.

The hinging pin engaging elements can comprise a series of ring structures, arranged slanted relative to the transport surface, wherein the ring structures comprise two series of aligned, slanted rings, each configured to engage a hinging pin. By arranging the rings slanted, the manufacturing of the individual links may be less complex. Typically these links are manufactured by means of injection molding. Rings with openings substantially perpendicular to the the opening direction of the mold, by nature comprise undercut sections and require slides or pin inserts in the mold in order to be able to mold the links. By sufficiently slanting the ring containing elements, the rings may be formed, while no undercut is present. Thus no pin inserts or slides may be necessary, which could greatly simplify the molds needed.

Consecutive links in the chain can have hinging pin stoppers on alternating lateral sides of the chain, such that a hinging pin is facing at its first abutting side a first stopper from a first link and at its second abutting side a second stopper from a second link.

Thus, by connecting the consecutive links with the pins, the links snap into connection, where the hinging pins cannot slide out. The snap fit renders the manufacture of the chains easier, since no tools or additional parts are needed to produce the chains.

The conveyor links of each conveyor track are guided by a set of guiders, configured to allow the hinging pins of the conveyor chain to slide along. Thus, the tracks are born on the hinging pins, possibly reducing wear and friction as indicated herein above.

At the turns, the guiders can comprise two rounded edges, configured to guide the tracks around, wherein the distance between the rounded edges increases towards the curve outside of the transport conveyor. Since the hinging pins can slide over the guiders, it further simplifies the design and manufacture of the transport conveyor, while it may reduce wear and possibly, the needed drive power.

The radius of the edges of set the guiders of each track increases towards the curve outside of the conveyor track and the average diameter of the rounded edges of the sets of guiders of each individual parallel tracks is substantially equal compared to the other tracks. In order to guide the individual tracks with the wedge-shaped links through the corner, the sliders of each track need to mimic the shape of a set of conical idlers. Thus, the outside guider for each track need to have an increased diameter on the curve outside position. Yet the average radius of the rounded edges of the parallel tracks may be chosen substantially equal, such that the gaps at the intake and offload end remain relatively small. Here the distance between the two rounded edges of the guiders may need to increase, in order to compensate for the higher track length of the tracks towards the curve outside of the transport conveyor.

The conveyor chain is substantially borne by the hinging pins, moving over the guiders. Both in the curves and in the transport part of the individual conveyor tracks, the chains may be guided by the hinging pins sliding over guiders. This can reduce the friction forces and wear as indicated herein above.

In order to further elucidate the invention, exemplary embodiments will be described with reference to the figures. In the figures:.

The figures represent specific exemplary embodiments of the inventions and should not be considered limiting the invention in any way or form. Throughout the description and the figures the same or corresponding reference numerals are used for the same or corresponding elements.

The term ring-shaped is to be considered as, yet not to be seen as limited to an open through-going space surrounded by material, irrespective of the shape. Thus the material may be in the shape of a ring around the through going space, in the shape of an oval, a square, a long hole and/or any specific form suited for the purpose.

<FIG> depicts a schematic perspective view of a conventional curved path conveyor <NUM> for small radius turns. The conveyor <NUM> comprises a frame <NUM> having two guiding edges <NUM> and <NUM>. Guiding edge <NUM> is located on the curve outside <NUM> and guiding edge <NUM> is located on the curve inside <NUM>. In between the guiding edges <NUM> and <NUM> is located a support surface <NUM>, comprising a set of curved supports 6A-D. On the curved supports 6A-D a transport chain <NUM> can slide, being kept in position in horizontal sense by the guiding edges <NUM> and <NUM>. The conveyor chain <NUM> comprises a series of wedge shaped hinging links <NUM>. The pitch <NUM> of the individual links is larger on the curve outside <NUM> than on the curve inside <NUM>.

The conveyor chain <NUM> is an endless loop, which for instructive purposes is partially removed. The loop runs between two turns around an idler 9B at a first side and a drive 9A at the other side. The drive comprises a series of sprocket wheels 11A-11E of increasing diameter towards the curve outside <NUM>. The Teeth of the sprocket wheels 11A-11E engage with the hinging pins of the links <NUM>. Since the links get wider towards the curve outside <NUM>, the distance between the dents, accommodating the hinging pins, in the sprocket wheels get correspondingly larger as well towards the curve outside <NUM>. Here typically the number of teeth per sprocket wheel of all the wheels is the same.

Since the shape of the conveyor track <NUM> is defined by wedge shaped links <NUM>, the conveyor track <NUM> defines a segment of an annular shaped track, which comprises a return part below a transport part. The outer circumference of the conically shaped drive 9A and a line directed towards an imaginary centre point P defines a wedge-shaped gap <NUM>, of which the diameter is increasing towards the curve inside <NUM>. The larger the width <NUM> of the track and/or the tighter the curve, the larger the gap <NUM> will be at the curve inside <NUM>.

The size of this gap at the curve inside <NUM> can limit the width and the tightness of the curve of the conveyor <NUM>. If the size gets to large, products to be transported on the conveyor <NUM> may fall through the gap or get stuck in the gap. This can lead to unintentionally product loss and downtime of the conveyor.

The <FIG> depicts a schematic perspective view of a set of parallel conveyor tracks 7A, 7B and 7C of a conveyor <NUM>. The tracks 7A, 7B and 7C comprise respectively wedge shaped links 8A, 8B and 8C. The tracks are driven by a set of sprocket wheels 24A-24F having an ascending diameter towards the curve outside <NUM>. The pitch of the links 8A-C in the consecutive corresponding chain tracks 7A-C are substantially corresponding. The pitch of the links of the individual tracks in relation to each other would lie within approximately a margin of <NUM>%. This provides the advantage that the idlers 17A-C, 18A-C, 21A-C and 22A-C where the chain tracks 7A-C turn, can be each of a limited diameter. Thus, the gap 12B, shown in <FIG>, between the lines L1 and the outer circumference of the idlers 18A-C can be reduced, when compared with the gap <NUM> between line L1 and the outer circumference of idler 9B and the line L1, shown in <FIG>.

The idlers 18A-C, 19A-C, 20A-C, 21A-C, 22A-C are each individually and separately from the other idlers rotatable. Typically, the idlers 18C-22C on the curve outside <NUM> will rotate faster than the idlers 18A-22A on the curve inside <NUM>. The chain tracks 7A-7C are driven by a series of shaft mounted sprocket wheels 24A-24F. The sprocket wheels 24A-24F comprise an increasing diameter towards the curve outside <NUM>, as is depicted in <FIG> and <FIG>. The sprocket wheels 24A-B, 24C-D, 24E-F are pairwise coupled to the individual conveyor chain tracks 7A, 7B and 7C respectively. The sprocket wheels 24A-B, 24C-D, 24E-F are pairwise comprising an increasing number of teeth 25A-B, 25C-D, 25E-F to accommodate the hinging pins of the links 8A, 8B and 8C respectively of the individual conveyor chain tracks 7A, 7B and 7C respectively. The contact angle between each of the individual conveyor chain tracks 7A-C and the sprocket wheels is substantially the same, in order to have the conveyor chain tracks 7A-7C each move with substantially the same angular speed through the curve of the conveyor <NUM>.

In <FIG>,<FIG> and <FIG> a set of two links is depicted in various views. The view of <FIG> is a front side view, indicated by arrow A in <FIG> and <FIG>. In these figures a set of two links <NUM> and <NUM> is depicted. The link <NUM> comprises two sets 28A-F and 29A-F of hinging pin engaging elements, connected to support structure <NUM>. Each set comprises a set of aligned rings, such that a hinging pin e.g. <NUM> or <NUM> can be inserted. The rings of the hinging pin engaging elements comprise surfaces that are slanted relative to the transport surface <NUM> as is indicated in <FIG>. Here the line N is the axis perpendicular to the transport surface <NUM>. O is an axis parallel to the slanted surface of the hinging pin engaging elements 28D. The angle α is chosen such, that the rings have no undercut portions seen in the direction of the line N. The hinging pins <NUM> find a stopper <NUM> of link <NUM> at a first lateral side of the chain, i.e. the curve outside <NUM> and a second stopper <NUM> of link <NUM> at a second lateral side of the chain, i.e. the curve inside <NUM>. Thus, a link can be snapped in its operating position, if two consecutive links <NUM> and <NUM> are provided and linked together. In order to do so, the stoppers <NUM> or <NUM> need to be elastically deformed, such to allow the pin <NUM> to be inserted in the set of hinging pin engaging elements 29A-<NUM> and 31A-<NUM> of links <NUM> and <NUM> respectively. Once the end of the pin <NUM> is passed the stoppers <NUM> or <NUM>, the stopper in question is allowed to snap back to its original undeformed state, therewith enclosing the pin <NUM> and avoiding the pin to escape.

In <FIG> a front side view of the set of two links <NUM> and <NUM> is depicted. The support structure <NUM> of link <NUM>, to which the hinging pin engaging elements 28A-H and 29A-H are attached extends beyond the hinging pin engaging elements 28A-H and 29A-H at a first side I, i.e. the side to which support surface <NUM> is facing.

The support structure <NUM> does not extend beyond the hinging pin engaging elements 28A-H and 29A-H at a second side II. Thus, the support structure does not extend beyond the hinging pin <NUM>. This allows the hinging <NUM> and <NUM> to rest on guiders <NUM> and <NUM> of the frame of the conveyor bend. Since the hinging pin engaging elements of the consecutive links are aligned in a transport direction A, all the links <NUM>, <NUM> can be born on the hinging pins <NUM> and <NUM>. Thus a smooth transport of the entire belt can be arranged, while the hinging pins are sliding over guiders.

In <FIG> is depicted a conveyor belt curve in which the set of return idlers 17A-C, 18A-C, 21A-C and 22A-C as depicted in the <FIG> can be replaced by a set of guiding shoes 40A-H.

Since the links <NUM> and <NUM> can be born by the hinging pins <NUM> and <NUM>, the guiding shoes 40A-H can allow a return of the individual conveyor tracks while the contact between the links <NUM> and <NUM> and the frame <NUM> predominantly is born by the hinging pins <NUM> and <NUM>.

Similar to the idlers, the return curves of the inner and the outer tracks are relatively similar. Each of the guiding shoes 40A-H comprise two rounded edges, configured to guide the tracks around. The distance between the rounded edges increases towards the curve outside of the transport conveyor, such that a smooth transport of the chain over the guiders can be obtained. By this increasing distance, the outer belt track is allowed to travel a longer distance between the upper and lower rounded edges, such to compensate for its longer traveling path.

The invention is to be understood to be according to the appended claims and not to be limited to the exemplary embodiments shown in the figures and described in the specification. For instance in the description drives are described as a set of sprocket wheels, alternatively, the drive may be a drum, where again the contact angle between the conveyor belt tracks and the drum are substantially equal for all the individual tracks. The links in the various embodiments are depicted as alternating links <NUM> and <NUM>. Alternatively, also a single-type-link belt for each track may be chosen, where the link engaging elements of the trailing side are sufficiently laterally offset from those hinging pin engaging elements of the leading side of the link, such that they fit in between each other and allow a hinging pin in. Here again at a first lateral side a first stopper and at a second lateral side a second stopper can be arranged such that the pins can only snap in when two links are connected by the pin.

Claim 1:
A transport conveyor curve (<NUM>) comprising a multitude of separate parallel curved conveyor tracks (7A-7C);
wherein the separate parallel curved conveyor tracks (7A-7C) are driven by a conical drive (<NUM>, <NUM>),
wherein the contact angle of each of the individual conveyor tracks (7A-7C) with a conical drum or with a series of drive gears or sprockets (24A-24F) with a, towards the direction of the outside (<NUM>) ascending diameter of the conical drive (<NUM>, <NUM>) is substantially equal in comparison to the contact angle of the other individual conveyor tracks (7A-7C) to move the individual conveyor tracks (7A-7C) with a corresponding angular speed through the curve, characterised in that the separate parallel curved conveyor tracks (7A-7C) comprise wedge-shaped links (8A-8C, <NUM>, <NUM>),
wherein the angle of the wedge of the wedge-shaped links (8A-8C, <NUM>, <NUM>) is smaller of an outer conveyor track (7C), when compared with the angle of the wedge of the wedge shaped link (8A-8C, <NUM>, <NUM>) of a more inner conveyor track (7A or 7B),
and wherein the returns of the transport conveyor curve comprise a series of idlers (17A-17C, 18A-18C, 21A- 21C, 22A-22C) or guiders (40A-<NUM>), wherein each parallel conveyor track (7A-7C) comprises its own set of idlers (17A-17C, 18A- 18C, 21A- 21C, 22A-22C) or guiders (40A-<NUM>).