Patent Description:
The invention relates generally to power-driven conveyors and, more particularly, to conveyor systems having conveyor belts with object-supporting rollers rotated by contact with a drive mechanism having freely rotatable drive rollers whose orientations are changeable to cause the object-supporting rollers to rotate in one direction or another.

It is often necessary to divert objects from a conveyor belt, for example to another conveyor belt, for purposes of routing or positioning the objects for processing of one type or another.

<CIT> describes a conveyor system for diverting objects carried atop a conveyor belt having object-supporting rollers. As the conveyor belt advances in a direction of belt travel, the belt rollers ride on freely rotatable drive rollers supporting the conveyor belt from below. The belt rollers are arranged in lanes and rotate on axes parallel to the direction of bet travel. The drive rollers are mounted in pivotable cartridges. An actuator coupled to the cartridges pivots the cartridges and the drive rollers in place and in contact with the belt rollers. When the drive rollers are pivoted to oblique angles relative to the conveyor belt rollers, the belt rollers are rotated to direct conveyed objects toward one side of the conveyor belt or the other depending on the angle of the drive roller relative to the direction of belt travel.

<CIT> discloses a roller belt conveyor having an array of pivot rollers defining a conveying surface that supports an article being conveyed in a first conveying direction, at least one plate pivotally coupled to at least a subset of the array of pivot rollers, and an actuator coupled to the at least one drive plate, such that, the actuator may manipulate the at least one drive plate to adjust an angular orientation of the at least one subset of the array of pivot rollers from the first conveying direction to a second conveying direction. More particularly, <CIT> discloses a drive roller assembly according to the preamble of claim <NUM>.

The invention relates to a conveyor belt having a plurality of conveyor belt rollers configured to divert objects atop the rollers as the belt advances and a drive roller assembly for selectively driving the conveyor belt rollers. The drive roller assembly includes a plurality of pivotable rollers carriers, each having an orientation element and a freely rotatable drive roller that contacts the conveyor belt rollers from below. An actuator engages the carrier orientation element to pivot the carrier and change the orientation of the drive rollers with respect to the conveyor belt rollers. The drive rollers may also move into and out of engagement with the conveyor belt rollers as their orientation with respect to the conveyor belt rollers changes. Wearstrips may be inserted into notches forming in the drive roller assembly to form a carryway across the width of the drive roller assembly. The drive roller assembly may be a modular assembly that can be customized for varying sizes, shapes and configurations.

According to the invention, a drive roller assembly for selectively actuating conveyor belt rollers in a conveyor belt configured to divert objects atop the conveyor belt rollers as the conveyor belt advances along a carryway is provided. The drive roller assembly comprises a plurality of pivotable roller carriers housing freely rotatable drive rollers that contact the conveyor belt rollers from below the conveyor belt, a three-dimensional top support plate, a translatable orientation device for engaging the pivotable roller carriers to change the orientation of the drive rollers with respect to the conveyor belt rollers and an actuator for selectively moving the translatable orientation device to pivot the pivotable roller carriers. The three-dimensional top support plate includes an array of openings arranged in a quincunx pattern. The roller carriers extend through the openings. The three-dimensional top support plate includes at least one corrugated vertical wall extending longitudinally on the top support plate between a first and second column of openings, each corrugated vertical wall including a plurality of notches in a top edge for receiving a wearstrip. Each curve in the corrugated vertical wall partially surrounds an opening.

According to another aspect not being part of the invention, an orientation plate for a drive roller assembly comprises a planar substrate with a plurality of elongated openings, a cam mechanism including a carrier opening for receiving a roller carrier within an elongated opening and a flexible leaf connecting the cam mechanism to the planar substrate.

According to another aspect not being part of the invention, a wearstrip holder for a drive roller assembly comprises a corrugated vertical wall extending longitudinally and a plurality of notches in an upper edge of the wall for receiving a wearstrip.

According to another aspect not being part of the invention, a method of assembling a drive roller assembly comprises the steps of inserting a plurality of fasteners into lateral top slots extending from a top wall of a support frame and placing a plurality of bottom support plate modules over the support frame, such that a plurality of fasteners are inserted through fastener openings in each bottom support plate modules. Each bottom support plate module includes an array of bottom roller carrier openings. The method further comprises the steps of placing a translatable orientation device over the plurality of bottom support plate modules, each translatable orientation device including an array of elongated orienting openings, each elongated orienting opening including a linear array of teeth, and then placing a plurality of top support plate modules over the translatable orientation device, such that a plurality of fasteners are inserted through fastener openings in each top support plate module. Each top support plate modules includes an array of top roller carrier openings. The method further comprises the steps of aligning and fastening edge top and bottom support plate modules to each other, aligning remaining top and bottom support plate modules relative to the edge top and bottom support plate modules using an alignment tool, fastening remaining top and bottom support plate modules to each other and aligning the translatable orientation device relative to the top and bottom support pate modules using the alignment tool, so that the bottom roller carrier openings, orienting openings and top roller carrier openings are aligned with each other. The method then comprises the steps of attaching a moving actuator clevis to the translatable orientation device, mounting an actuator and static actuator clevis within the support frame and inserting roller carriers through the aligned top roller carrier openings, orienting openings and bottom roller carrier openings.

The disclosed systems and methods can be understood with reference to the following drawings. The components in the drawings are not necessarily to scale.

As described above, existing conveyor systems that include conveyor belt rollers, although providing advantages over previous systems, still have limitations.

Referring to the figures, in which like numerals indicate corresponding parts throughout the several views, <FIG> illustrate an embodiment of a portion of a conveyor system <NUM> that can be adjusted to divert objects at various angles to either side of the system. As indicated in <FIG>, the conveyor system <NUM> comprises a roller conveyor belt <NUM> and a field <NUM> of angularly adjustable "drive" roller modules <NUM> below the conveyor belt. In the embodiment of <FIG>, the conveyor belt <NUM> comprises a plurality of hingedly-connected transverse modular conveyor belt modules <NUM>. The belt is constructed of a series of rows of one or more belt modules connected side to side and end to end at hinge joints into an endless belt loop advancing along a portion of a conveyor carryway in a direction of belt travel <NUM>. The conveyor belt is reversible and may travel in an opposite longitudinal direction from direction <NUM>.

One or more of the conveyor belt modules <NUM> includes free-spinning conveyor belt rollers <NUM> for selectively diverting objects carried by the conveyor belt <NUM>. The object-supporting rollers <NUM> can be mounted on axles and extend longitudinally in the direction of belt travel <NUM> to enable the object-supporting rollers <NUM> to selectively divert objects to either side of the conveyor belt. For the purposes of this disclosure, the term "free-spinning" means that the rollers are free to spin about their axes of rotation in either angular direction. Therefore, the rollers <NUM> may be said to comprise "idler" rollers that will freely rotate in either angular direction when driven by an appropriate force. In the embodiment of <FIG>, the rollers <NUM> are positioned such that their axes of rotation are parallel to the direction of belt travel <NUM>. The rollers <NUM> can be alternately provided in another orientation.

The conveyor belt rollers <NUM> are made of metal and/or plastic or another suitable material and may be provided with a rubber or plastic high-friction outer layer or coating that prevents slippage when rollers of the drive roller modules <NUM> are brought into contact with the conveyor belt rollers. The rollers <NUM> are dimensioned so as to extend beyond the upper and lower surfaces of the conveyor belt <NUM> (and belt module bodies <NUM>) such that they can both divert objects placed on the conveyor belt <NUM> and can be selectively driven from below by the drive roller modules <NUM>, though the invention is not limited.

Referring to <FIG>, the field <NUM> of angularly adjustable drive roller modules <NUM> comprises one or more drive roller assemblies <NUM>, each assembly <NUM> individually controlled and actuatable. A conveyor <NUM> may include multiple drive roller assemblies <NUM> arranged in various configurations to customize or otherwise vary the number, arrangement and -or size of the field <NUM> of drive rollers modules <NUM>. Each drive roller assembly <NUM> comprises an array of drive roller modules <NUM> for selectively engaging conveyor belt rollers <NUM>. Each drive roller module <NUM> comprises a freely-rotatable drive roller <NUM> housed in a roller carrier <NUM> to form an angularly adjustable roller module <NUM>. Each roller carrier <NUM> can pivot about a vertical axis to change the orientation of the drive roller <NUM>. The rolling contact between the belt rollers <NUM> and the drive rollers <NUM> causes them both to roll on each other and rotate as long as their axes are oblique to each other. In the illustrative array of drive rollers <NUM>, each column of drive rollers is offset longitudinally (in a direction of belt travel <NUM>) from an adjacent column of drive rollers in a quincunx pattern, to increase the density of the array, though the invention is not so limited.

The roller carriers <NUM> are mounted through a shaped, three-dimensional top support plate <NUM>, which may comprise a plurality of modular plates extending laterally across the width of the assembly <NUM>. The top support plate <NUM> includes a plurality of openings <NUM> arranged in longitudinal columns <NUM> and lateral rows <NUM>. The columns of openings are laterally aligned with the lateral positions of the conveyor belt rollers <NUM>, with adjacent columns staggered relative to each other in a quincunx pattern to increase density, but the invention is not so limited. Each opening <NUM> rotatably receives a roller carrier <NUM> supporting a freely-rotatable drive roller <NUM>, which selectively engages the belt rollers <NUM> in the corresponding column as the belt <NUM> advances in the direction of belt travel <NUM>. The openings <NUM> are shaped and three-dimensional, having vertical walls extending up and circumscribing a portion of each roller carrier, as well as forming wear-strip receptacles and camming surfaces to selectively raise and lower the roller carriers <NUM>, as described below.

A translatable orientation device <NUM> engages orientation elements on the roller carriers <NUM> to selectively pivot the roller carriers <NUM> and their carried drive rollers <NUM> about their vertical axes. An actuator <NUM> selectively shifts the translatable orientation device <NUM> laterally to pivot the roller carriers <NUM> about their vertical axes. In the illustrative embodiment, the translatable orientation device <NUM> includes two spaced-apart translatable orientation plates 420a, 420b, which are joined together by a moving actuator clevis <NUM>, so that the translatable orientation plates 420a, 420b operate in unison. The translatable orientation device <NUM> may comprise multiple modules arranged laterally across the width of the assembly <NUM>, or may span the width of the assembly.

A bottom support plate <NUM>, which may comprise a plurality of modular plates extending laterally across the width of the assembly <NUM>, below the translatable orientation device <NUM> is connected to the top support plate <NUM> and provides lower bearing surfaces for the roller carriers <NUM>. Carrier openings <NUM> in the bottom support plate <NUM> receive the bottom portions of the roller carriers <NUM>. The openings <NUM> in the bottom support plate <NUM> are vertically aligned with, but smaller than the openings <NUM> in the upper support plate. The openings <NUM> help align the top and bottom support plates to facilitate assembly of the drive roller assembly, in addition to confining the roller carriers <NUM> in rotation on fixed vertical axes. The bottom support plate <NUM> and top support plate <NUM> are fixed relative to each other and static, with the translatable orientation device <NUM> slidably sandwiched in between the support plates <NUM>, <NUM>. The illustrative top and bottom support plates <NUM>, <NUM> can be formed of plastic or another suitable material. In one embodiment, the top and -or bottom support plates are formed through an injection molding process, <NUM>-D printing or another suitable process.

A support frame <NUM> below the bottom support plate <NUM> provides support for the assembly <NUM>. The illustrative support frame <NUM> comprises an extruded aluminum structural member having a channel shape. In another embodiment, the support frame <NUM> is formed from "pull-truded" plastic, formed sheet metal or any other suitable material and - or process. Attachment features, such as t-slots, clearance slots and screw bosses are formed in the support frame to attach other components of the assembly <NUM> to the frame <NUM>, as described below. Alignment tabs <NUM> on each side of the assembly engage with mating slots in the support frame <NUM> to precisely align the drive roller assembly <NUM> in a vertical direction.

A static actuator clevis <NUM> forms an attachment point to connect a fixed rod eye of the actuator <NUM> to the support frame <NUM>. A moving actuator clevis <NUM> connects the dynamic rod eye of the actuator <NUM> to the translatable orientation plates 420a, 420b, and the plates 420a, 420b to each other. The illustrative actuator <NUM> is a pneumatically-activated cylinder and piston that can selectively move the orientation plates <NUM> to effect rotation of the carriers <NUM> and change the orientation of the drive rollers <NUM>, but any suitable actuator for selectively translating the orientation device <NUM> in order to change the orientation of the drive rollers <NUM> may be used.

In addition, the drive roller assembly <NUM> includes wearstrips <NUM> forming a carryway for the conveyor belt <NUM>, supporting the conveyor belt across its width. The illustrative wearstrips extend in the direction of belt travel <NUM> and span the length of the assembly <NUM> and are spaced apart between every-other column <NUM> of drive rollers. The illustrative wearstrips are formed of UHMW-PE through extrusion, but the invention is not so limited. Recesses in upper surfaces of the upper support plate <NUM> are designed to hold the wearstrips <NUM> in a selected position relative to the drive rollers <NUM>, as described below.

Referring to <FIG>, an illustrative the support frame <NUM> comprises vertical side walls <NUM>, <NUM>, a vertical interior wall <NUM> and a horizontal top wall <NUM>. Lateral top slots <NUM> extend from the horizontal top wall <NUM> for receiving fasteners to connect the top and bottom support plates <NUM>, <NUM> to the support frame <NUM>, as well as fasteners for connecting the alignment tab <NUM> to the support frame. The illustrative top slots <NUM> are formed by vertical slot walls <NUM> and horizontal upper walls <NUM> to form a slot in the shape of an upside-down "T". The support frame <NUM> includes interior slots <NUM>, <NUM> extending laterally and facing inwards from a first vertical side wall <NUM> and the vertical interior wall <NUM> for mounting the actuator <NUM>. Lateral openings <NUM>, <NUM>, <NUM>, <NUM> receive fasteners to fasten the support frame <NUM> to a conveyor frame. Each lateral fastener opening <NUM>, <NUM>, <NUM>, <NUM> is below a T-shaped slot <NUM>, <NUM> or <NUM>, but the invention is not so limited.

The support frame <NUM> houses the actuator <NUM>, as well as the static clevis <NUM> and moving clevis <NUM>. Lateral clearance slots <NUM> (seen in <FIG>) in the top wall <NUM> receive bosses in the moving clevis <NUM>. The moving clevis bosses receive fasteners to secure the moving clevis <NUM> to the orientation plates <NUM> to effect translation of the connected orientation plates 420a, 420b when the actuator <NUM> moves the moving clevis <NUM>, as described below.

The illustrative support frame <NUM> extends about <NUM> inches in the longitudinal direction <NUM>, which is the direction of travel of the conveyor belt.

For a shorter support frame <NUM>, as shown in <FIG>, the central support wall <NUM> can be omitted, with the lateral t-shaped top slots <NUM>' closer together, depending on a desired configuration.

In an illustrative embodiment, rotation of the roller carrier <NUM> serves not only to orient the associated drive roller <NUM>, but also to raise and-or lower the drive roller <NUM> into or out of engagement with a conveyor belt roller <NUM>. Orientation of the drive roller <NUM> in a non-diverting orientation lowers the drive roller <NUM> out of engagement with the conveyor belt, while orientation of the drive roller <NUM> in a diverting orientation raises the drive roller <NUM> into engagement with the conveyor belt. For example, referring to <FIG> and <FIG>, in one embodiment, one, several or all of the roller carriers <NUM> can include cam surfaces that cause the roller carrier <NUM> to rise automatically relative to the top support plate <NUM> when the actuator <NUM> orients the roller carrier <NUM> in a selected position.

The illustrative self-rising roller carrier <NUM> comprises a retainer ring <NUM> with diametrically opposite holes <NUM> supporting the ends of an axle <NUM> of a drive roller <NUM>. A downward-facing cam surface <NUM> is formed on the bottom of the retainer ring <NUM>. The downward-facing cam surface <NUM> coacts with an upwardly-facing cam surface <NUM> on the top support plate <NUM> (shown in <FIG> and <FIG>) circumscribing the opening <NUM> in which the roller carrier <NUM> is received to selectively raise and lower the retainer ring <NUM> as it pivots about its vertical axis. The illustrative cam surfaces <NUM>, <NUM> are lobed, with ramp sections, to effect vertical movement of the drive roller <NUM> during pivoting about a vertical axis, but the invention is not so limited.

Referring to <FIG>, an upper journal stem <NUM> extends downwards from the retainer ring <NUM> and encircles the drive roller bottom. A lower journal stem <NUM> distal from the retainer ring <NUM> has a smaller diameter than the upper journal stem <NUM>. The periphery of the lower journal stem <NUM> is indented inward of the periphery of the upper journal stem <NUM>. In an upper portion, the lower journal stem <NUM> includes a sector of gear teeth <NUM> or another suitable orientation element for engaging the translatable orientation device <NUM> to induce rotation of the roller carrier <NUM>. Other suitable means for orienting the roller carriers may be used. In the illustrative embodiment, the tips of the gear teeth <NUM> do not extend past the periphery of the upper journal stem <NUM>. The illustrative teeth <NUM> also do not extend around the entire periphery of the lower journal stem <NUM>, leaving a space in the upper portion of the lower journal stem <NUM> that lacks teeth. The distal end of the lower journal stem can include locking tabs <NUM> that engage with slots formed in the bottom support plate <NUM>, as described below, to prevent the roller carriers <NUM> from disengaging during operation.

In another embodiment, shown in <FIG>, a roller carrier <NUM> includes a flat bottom <NUM> on the bottom of a retainer ring <NUM>, which rides atop the surfaces <NUM> of the top support plate, to create rotational orienting motion with no vertical linear motion. In this embodiment, the drive roller <NUM> maintains constant contact with the belt roller <NUM>. The roller carrier <NUM> is otherwise similar to the roller carrier <NUM>, including teeth <NUM>, a lower journal stem <NUM> and locking tabs <NUM>.

Referring to <FIG>, <FIG>, <FIG>, <FIG>, <FIG> and <FIG> the illustrative top support plate <NUM> is three-dimensional and modular, each module comprising a planar substrate forming roller carrier openings <NUM> with shaped camming surfaces <NUM> forming the rims of the roller carrier openings <NUM>. The openings <NUM> are arranged in a quincunx pattern, with adjacent columns offset longitudinally from each other, such that the openings in one column are staggered and disposed halfway between the openings of an adjacent column. The illustrative top support plate module <NUM> comprises four staggered columns and six staggered rows of twelve total openings, but the invention is not so limited, and a top support plate module may comprise any suitable number and arrangement of openings. Multiple top support plate modules <NUM> can be arranged laterally along the width of the drive roller assembly <NUM>, depending on the width of the particular conveyor belt used with the drive roller assembly <NUM>.

Vertical upper walls <NUM> extend up from the planar base and terminate in upper edges that include shaped recesses <NUM> forming holders for the wearstrips <NUM>. As shown in <FIG>, <FIG>, <FIG> and <FIG>, in an illustrative embodiment, the vertical upper walls <NUM> comprise substantially corrugated vertical walls extending longitudinally in the direction of belt travel <NUM> between alternating, adjacent columns of openings <NUM>. Each corrugated upper wall <NUM> has curves that surround at least a portion of the openings <NUM> in each adjacent column. When the modular drive assembly <NUM> is assembled, the corrugated vertical walls also surround at least a portion of the roller carriers <NUM> inserted in the openings <NUM>. The vertical upper walls <NUM> alternate between the columns, leaving space between every other column. In one column, the vertical wall <NUM> wraps around a first side of openings <NUM>, while for an adjacent column, the vertical wall <NUM> wraps around a second side of the openings <NUM> in the second column. The illustrative top support plate module <NUM> includes two corrugated vertical walls <NUM>: a first corrugated vertical wall extending longitudinally between the first and second column of openings <NUM> and a second corrugated vertical wall extending longitudinally between the third and fourth column of openings <NUM>, but the invention is not so limited.

The illustrative wearstrip recesses <NUM> are formed at inflection points in the corrugated vertical wall, but the invention is not so limited. The illustrative recesses <NUM> are dovetail-shaped to compressively engage bulb-shaped protrusions on the wearstrips <NUM>, as described below. The recesses <NUM> may provide an interference fit to secure the wearstrips <NUM>, as described below.

In the illustrative embodiment, the faces of the corrugated vertical walls <NUM> that face an opening <NUM> are curved to match the shape of the opening <NUM>, while an opposing face <NUM> that does not face an opening <NUM> may be flat, but the invention is not so limited. In addition, corrugated vertical walls <NUM> at selected or all apexes and troughs may include a notch <NUM>. The corrugated vertical walls <NUM> may further include buttressing extensions to provide additional support for the structure. In an illustrative embodiment, the buttressing extensions comprise curved gussets <NUM> having top surfaces <NUM> that angle down towards the camming surfaces <NUM>. The illustrative curved gussets <NUM> are formed between the second row and third row of openings <NUM> and between the fourth row and fifth row of openings alongside each apex, with a shorter gusset <NUM> extending from the corrugated wall opposite from each curved gusset <NUM> of each notch <NUM>. Each curved gusset <NUM> intersects with the corrugated wall main portion and forms a shallow "s" shape with another curved gusset <NUM> that extends along an opening <NUM> in an adjacent column. Together, the gussets <NUM>, <NUM> form a vertical slot with the flat walls <NUM> along and extending down from each notch <NUM> for receiving a wearstrip stopper <NUM>, shown in <FIG> and <FIG>.

As shown in <FIG>, the corrugation in the corrugated vertical wall <NUM> has a wavelength λ and pattern that repeats over <NUM> times along the longitudinal length of a top support plate module <NUM>. At a first end, the corrugated vertical wall <NUM> starts at a first apex <NUM> and curves to a first trough <NUM>. Shorter gussets <NUM> extend from the corrugated vertical wall <NUM> at a first inflection point <NUM>. From the trough <NUM>, the vertical wall curves towards a second apex <NUM>, with curved gussets <NUM> extending from the corrugated vertical wall at a second inflection point <NUM>. Wearstrip recesses <NUM> are formed in the top edge at the inflection points <NUM>, <NUM>. Then, the pattern repeats until the end of the top support plate module <NUM>. While the illustrative corrugated vertical wall <NUM> is continuous along the length of the top support plate <NUM>, alternatively, the corrugated vertical wall <NUM> may be non-continuous.

The illustrative top support plate <NUM> further includes fastener openings <NUM>, <NUM>, as shown in <FIG>, for receiving fasteners to fasten the top support plate <NUM> to a bottom support plate <NUM> and the support frame <NUM>, as described below. In the illustrative embodiment, a corner fastener opening <NUM> is larger than the other openings <NUM> to receive a fastener having a bushing, as described below.

As shown in <FIG> and <FIG>, a wearstrip stopper <NUM> can snap into a top support plate <NUM> at a downstream end of a drive roller assembly to preventing the wearstrip <NUM> from sliding downstream, with legs received in one or more notches <NUM>. The stopper <NUM> can be included with each top support plate <NUM>, or selective top support plates, such as the downstream-most top support plate module in a drive roller assembly <NUM>.

The illustrative wearstrip stopper <NUM> comprises an upper wearstrip portion <NUM>, a pair of legs <NUM>, <NUM> on a first side of the upper wearstrip portion <NUM> and an offset leg <NUM> on a second side of the upper wearstrip portion at the longitudinal middle of the wearstrip stopper <NUM>. The legs <NUM>, <NUM>, <NUM> each include an upper connecting portion <NUM> configured to be received in a notch <NUM> in a corresponding corrugated vertical wall <NUM>. The legs <NUM>, <NUM>, <NUM> are each received in a vertical slot that is formed between a gusset <NUM>, a flat wall <NUM> and a curved gusset <NUM> extending along and down from the notch <NUM>, to lock the wearstrip stopper <NUM> to the top support plate <NUM>. The upper wearstrip portion <NUM>, which is configured to align with a wearstrip <NUM> inserted in an upstream portion of a top support plate <NUM>, includes a flange <NUM> that is received in recesses <NUM> to place the wearstrip stopper <NUM> into position. The flange <NUM> may be shaped to provide clearance for the roller carriers <NUM>. When inserted, the wearstrip stopper <NUM>, as shown in <FIG>, provides a continuation of the wearstrip surface, while the longitudinal restriction provided by the legs <NUM>, <NUM>, <NUM> prevents the weight and movement of the conveyor belt from sliding the wearstrip(s) <NUM> out of place.

In one embodiment, a wearstrip <NUM> includes a bulb-shaped protrusion <NUM> on the bottom surface that is received in recesses <NUM>, via a compression fit, as shown in <FIG>. The illustrative bulb-shaped protrusion <NUM> may include straight, diverging sides and a curved, convex bottom surface, but the invention is not so limited. The fit between the protrusion <NUM> and the recess <NUM> is designed to have space between the bottom of the protrusion <NUM> and the bottom of the recess <NUM>, but the invention is not so limited.

The wearstrip <NUM> may be fabricated as a straight extrusion that may bend slightly to fit in to the recesses <NUM>. For example, the wearstrip-receiving recesses <NUM> may be slightly offset from each other, to create a serpentine-path, and the wearstrip <NUM> may bend during insertion to form a serpentine shaped. The serpentine shape in the wearstrip <NUM> prevents or limits the wearstrip <NUM> from sliding during operation.

In another embodiment, shown in <FIG> a wearstrip <NUM> includes notches <NUM> between protrusions <NUM> to provide a geometric lock with the top support plate <NUM>. In the embodiment of <FIG>, the protrusions <NUM> have straight sides, side indents and a bottom bulb with curved sides and a flat bottom, but the invention is not so limited.

Referring to <FIG> and <FIG>, a drive roller assembly <NUM> can comprise a plurality of top support plate modules and bottom support plate modules connected to each other to form a subassembly <NUM> receiving an array of drive roller modules <NUM>. A number of modular subassemblies <NUM> can be attached to a support frame <NUM> as needed to create a drive roller zone <NUM> with different widths suitable for the configuration of a particular conveyor belt. And, as described above, a number of drive roller assemblies <NUM> can be used to vary the length of the drive roller zone <NUM>.

Each subassembly <NUM> can comprise a subarray of drive roller modules <NUM>, each comprising a roller carrier <NUM> housing a drive roller <NUM>, as described above. Carriage bolts <NUM> or other fastening devices extending through aligned fastening openings clamp a top support plate module <NUM>' and a bottom support plate module <NUM>' together. An aligning and fastening device <NUM>, which comprises a carriage bolt <NUM> or other fastener with a metal bushing, is used at one corner of the subassembly to align and anchor the subassembly <NUM> to the support frame. The aligning and fastening device <NUM> does not clamp the top and bottom support plates, but rather clamps underlying fastener to the underlying support frame <NUM>. The aligning and fastening device <NUM> creates a strong metal-to-metal connection to align each sub-assembly <NUM> along the width of the zone. The alignment slots <NUM> in the top of the support frame <NUM> receive the heads of the bolts <NUM> and <NUM> to secure the subassembly <NUM> to the support frame and the components to each other. The orientation device <NUM> is slidable received between the top and bottom support plate modules <NUM>, <NUM>'.

Referring to <FIG>, a bottom support plate module <NUM>' comprises a planar substrate <NUM> having carrier openings <NUM> for receiving the lower journal stems <NUM> of the roller carriers <NUM>. When assembled, the openings are aligned with and below the openings <NUM> in the top support plate <NUM>. The openings <NUM> include vertical slots <NUM> for receiving the tabs <NUM> on the bottom of the roller carriers <NUM>. The tabs <NUM> pass through the slots <NUM> during assembly, then clear a lip <NUM> rimming the interior of the openings <NUM>. Below the lip <NUM>, the openings <NUM> provide almost a full circle of clearance to allow the roller carriers <NUM> to rotate freely within the openings <NUM>, with a stopping protrusion <NUM> extending down from the lip <NUM> diagonal from the slot <NUM>. The lip <NUM> prevents the roller carriers <NUM> from popping out of the openings <NUM>.

During operation, the travel of the translatable orientation device <NUM> sheet is restricted by the stroke of the pneumatic actuator <NUM> so that the tabs <NUM> and slots <NUM> cannot align, preventing the roller carriers <NUM> from exiting the openings <NUM>. Only when the pneumatic actuator <NUM> is disconnected can the translatable orientation device <NUM> travel to a "service position" where the roller carriers <NUM> can be removed by aligning the roller carrier tabs <NUM> and bottom plate slots <NUM> and pulling the roller carriers <NUM> vertically.

Vertical buttresses <NUM> extend from, and can be integrally molded with, the top of the planar substrate <NUM> and include openings for fasteners <NUM>. The illustrative buttresses <NUM> provide vertical support for the top support plate <NUM>. The illustrative buttresses <NUM> include flat vertical end faces <NUM> forming wear surfaces that contact and guide the translatable orientation device <NUM>. When assembled, the buttresses <NUM> extend between the two orientation plates 420a, 420b. The illustrative buttresses <NUM> further resist, reduce and-or prevent gear separation forces that may be present in the system. The illustrative buttresses <NUM> include manufacturing recesses <NUM> for maintaining substantially uniform wall thickness throughout the feature to ease moldability, but the invention does not require these recesses <NUM> or the other shown features.

The bottom support plate <NUM> further includes a vertical boss <NUM> having another fastener opening for a fastener <NUM> and an alignment boss <NUM> in a corner having a larger opening for the aligning and fastening device <NUM>. The vertical boss <NUM> and alignment boss <NUM> are formed along a laterally-extending edge of the bottom support plate, which may be the upstream edge, but could alternatively be the downstream edge of the module. The bottom plate module <NUM>' further includes guidance features <NUM>, which may also be integrally molded with the planar substrate <NUM>. The guidance features <NUM> extend up from a side of at least some openings <NUM> and constrain the motion of the translatable orientation device <NUM>.

In addition, the illustrative bottom support plate <NUM> includes lateral rails <NUM> providing additional vertical support for the translatable orientation device <NUM>. The illustrative rails <NUM> contact the translatable orientation device <NUM> in locations lacking gear teeth or other laser-cut features to prevent wearing of the lateral rails. The space between the lateral rails <NUM> allows some debris to fall through without gumming up the motion of the translatable orientation device <NUM>.

Referring to <FIG>, the illustrative translatable orientation device <NUM> comprises a main plate 420a and a minor plate 420b. The orientation plates 420a, 420b are slidably sandwiched between the fixed upper support plate <NUM> and the bottom support plate <NUM>, both of which, as described above, can comprise a plurality of modules. Each orientation plate 420a, 420b is positioned to engage the teeth <NUM> of the roller carriers <NUM> to form a rack- and-pinion system that can rotate the roller carriers <NUM> in unison as the orientation plates 420a, 420b are translated by the actuator <NUM>. The orientation plates have orienting openings <NUM> elongated in the lateral direction. The elongated orienting openings <NUM> are bounded on one side by a linear array of teeth <NUM> forming a rack gear. Each elongated orienting opening <NUM> is positioned below one of the roller carrier openings <NUM> in the top support plate <NUM>, so each elongated opening <NUM> can receive a lower journal stem <NUM> of a roller carrier <NUM>. When the roller carriers are inserted, the lower journal stem <NUM> extends through the elongated orienting openings <NUM> in the orientation plate and into the smaller carrier openings <NUM> in the bottom support plate <NUM> below. Laterally-extending edges of the orientation plates 420a, 420b, shown as the upstream edges, also include teeth and are positioned to accommodate and engage selected roller carriers <NUM> in the array.

As shown in <FIG>, the main plate 420a and minor plate 420b are separated by a space <NUM> to accommodate the row of vertical buttresses <NUM> extending from the bottom support plate <NUM>, with a row of roller carriers received and housed in the space <NUM>, as shown in <FIG>. The main plate 420a has an end edge that is inset from the end edge of the bottom support plate <NUM> to accommodate bosses <NUM>, <NUM>, so that when assembled, as shown in <FIG>, the bosses <NUM> and <NUM> are adjacent the laterally-extending outer edge of the main plate 420a.

In addition, the illustrative guidance features <NUM> on the bottom support plate <NUM> are configured to extend between a non-toothed side of an elongated orienting opening <NUM> and the lower journal stem <NUM> of a roller carrier <NUM>. The flat side of each guidance feature <NUM> contacts the inside edge of the corresponding elongated orienting opening <NUM>. These faces provide wear surfaces and resist any gear separation forces in the system. The lack of teeth on that portion of the lower journal stem <NUM> enables inclusion of the guidance features <NUM>.

As shown in <FIG>, the orientation plates 420a, 420b are translated by a linear actuator <NUM>, such as an air cylinder. One end of the actuator <NUM> is attached to the static actuator clevis <NUM>, which connects the fixed rod eye of the actuator <NUM> to the support frame <NUM>. The illustrative static actuator clevis <NUM> includes four fasteners <NUM> that engage T-slots <NUM>, <NUM> along the inside of the support frame <NUM>. The fasteners can be tightened during assembly to connect the static actuator clevis <NUM> to the support frame <NUM>. At the other end, the moving actuator clevis <NUM> connects the actuator <NUM> to the orientation plates 420a, 420b. The moving actuator clevis <NUM> includes a plate <NUM> and a plurality of bosses <NUM> receiving fasteners <NUM> to connect to both orientation plates 420a, 420b to join the orientation plates together and allow them to operate in unison.

Referring back to <FIG>, the fasteners <NUM> extend through openings <NUM> in the orientation plates to secure both orientation plates 420a, 420b to the moving actuator clevis <NUM> and each other. Referring back to <FIG>, the bottom support plate <NUM> includes clearance slots <NUM> configured to allow passage of the fasteners <NUM>, which slide within the clearance slot <NUM>. As described above, the support frame <NUM> also includes clearance slots <NUM> for the fasteners <NUM> to enable sliding of the translatable orientation device <NUM>.

Referring to <FIG>, in one embodiment, the moving actuator clevis <NUM> may include a glide <NUM> on a bottom surface thereof. The illustrative glide <NUM> is formed of UHMW or another low-friction material to prevent the actuator <NUM> from rotating and reducing friction between the actuator <NUM> and moving actuator clevis <NUM>. In another embodiment, the outer surfaces <NUM> of the static actuator facing the slots <NUM>, <NUM> of the support frame <NUM> may include cross-hatching, knurling or have another feature to increase the grip between the support frame <NUM> and the static actuator <NUM>.

<FIG> shows a method of assembling a drive roller assembly <NUM> including modular top and bottom support plates. First, in step <NUM>, fasteners <NUM> are slid into the support frame slots <NUM>, such that the slots <NUM> retain the fastener heads and the fastener shank extend up, as shown in <FIG>. The number of fasteners <NUM> depends on the number of top and bottom support plate modules to be used, with four fasteners per top and bottom support plate module Then, in step <NUM>, a first bottom support plate module 322a is mounted over a first set of fasteners, as shown in <FIG>. Successive bottom support plate modules 322x are similarly mounted over successive sets of fasteners in a similar manner, until a desired width is achieved. In step <NUM>, translatable orienting plates 420a, 420b are placed over the bottom support plates modules, as shown in <FIG>. As shown in <FIG>, the translatable orienting plates 420a, 420b are placed over the array of bottom support plate modules so that each elongated opening <NUM> is over an opening <NUM>, bosses <NUM> with fasteners <NUM> extend between the main plate 420a and minor plate 420b and bosses <NUM>, <NUM> abut the upstream lateral edge of the main plate 420a.

Then, in step <NUM>, the top support plate modules 320a-320x are mounted by inserting each set of fasteners <NUM> through openings <NUM> and <NUM>, with opening <NUM> overlying and aligned with opening <NUM> of an underlying bottom support plate module <NUM>.

In step <NUM>, an edge bottom support plate module 322a is located in a precise position relative to the edge of the support frame <NUM>. The positioning may be done using a tool that engages an edge of the bottom support plate, markings or another method.

In step <NUM>, the edge top and bottom support plate modules 320a, 322a are fastened together and to the support frame by tightening nuts around three fasteners <NUM>, inserting a bushing over a corner fastener to form the alignment device <NUM> and tightening the fastener to a higher torque than the fasteners <NUM> alone.

In step <NUM>, the remaining top and bottom support plate modules are located relative to the edge top and bottom support plate modules and the main translatable orientation plate 420a. In one embodiment a plurality of alignment tools <NUM> are used to locate the remaining top and bottom support plate modules relative to the edge modules, as shown in <FIG>. The illustrative method employs four alignment tools: two that are inserted into edge top and bottom support plate modules 320a, 322a and the intermediate main orientation plate 420a and two that are inserted into each successive top and bottom support plate module being aligned with the edge modules and the intermediate main orientation plate 420a. After each set of modules is located and clamped using nuts on the fasteners <NUM>, the second set of alignment tools is inserted into a successive set of modules until all modules <NUM>, <NUM> are clamped together and to the underlying support frame <NUM> and the main orientation plate 420a is in position relative to the top and bottom support plate modules.

<FIG> is an isometric view of an alignment tool <NUM> suitable for use in aligning components of the drive roller assembly relative to each other during assembly. The alignment tool <NUM> includes a handle <NUM> and a head <NUM> configured to be received in an opening <NUM> of a top support plate, an elongated opening <NUM> of an orientation plate <NUM> and an opening <NUM> of an underlying bottom support plate and to precisely align the openings <NUM>, <NUM>, <NUM>. The head <NUM> comprises a top knob <NUM> that fits in the bottom opening <NUM>. The top knob <NUM> is substantially cylindrical, with a round perimeter wall <NUM> and a rectangular protrusion <NUM> extending from angled, converging flat walls <NUM>. The protrusion <NUM> is configured to be received in the vertical slots <NUM> of the bottom support plate <NUM> that receive the tabs <NUM> on the bottom of the roller carriers <NUM>. The top knob <NUM> is connected to the head base <NUM> by a neck <NUM>. The base <NUM> is configured to be received in and engage the elongated opening <NUM> of an orientation plate. The base <NUM> includes rounded sides, flat front and end walls and a tapering protrusion <NUM> configured to engage a central tooth <NUM> of the opening <NUM> to precisely position the orientation plate <NUM> relative to the bottom support plate. When inserted, the alignment tools <NUM> maintain the position of assembly components together until the fasteners <NUM> can be fastened, securing the top support modules and the bottom support plate modules to each other and to the underlying support frame <NUM>.

Then, in step <NUM>, the minor orientation plate 420b is aligned with the other components. In this step, as shown in <FIG>, the lower two alignment tools 600c, 600d are moved to openings <NUM> over the minor alignment plate 420b, with two alignment tools 600a, 660b remaining engaged with the main alignment plate 420a, to align and locate the minor alignment plate 420b relative to the other components. As shown, the alignment tools 600a-d are located near the edges of the assembly during this step.

In step <NUM>, the moving actuator clevis <NUM> is installed and attached to the translatable orientation plates 420a, 420b. As shown in <FIG>, while the alignment tools <NUM> are still inserted, the moving actuator clevis <NUM> is slid into the channel of the support frame <NUM>, so that the bosses <NUM> align with the clearance slots <NUM> of the support frame, the clearance slots <NUM> of the bottom support plate modules and the openings <NUM> of the orientation plates 420a, 420b. Fasteners <NUM> can then be inserted through aligned slots and openings and tightened to secure the moving actuator clevis <NUM> to the orientation plates 420a, 420b and the orientation plates 420a, 420b to each other.

Next, in step <NUM>, the actuator <NUM> and static actuator clevis <NUM> are inserted in the channel of the support frame and mounted loosely using fasteners, without fully fastening the components together. The actuator <NUM> can then be tested to see if it properly diverts the translatable orientation plate.

In a subsequent step, step <NUM>, the roller carriers <NUM> are installed the assembly in step <NUM>. In this step, the static actuator, though loosely mounted, is unconnected to the cylinder of the actuator. The translatable orientation sheets 420a, 420b are manually pushed to a far left or right "service" position, exposing the vertical slots <NUM> in the bottom plates <NUM>. The roller carriers <NUM> with drive rollers <NUM> can then be inserted through the openings <NUM>, <NUM> and <NUM>, as shown in <FIG>. After all the roller carriers <NUM> and drive rollers <NUM> are inserted, the translatable orientation sheets 420a, 420b are moved to a center position, and the static actuator clevis <NUM> is firmly attached to the actuator <NUM> using a bolt or other suitable fastener. Wearstrips <NUM> can be inserted in the wearstrip holders formed by the corrugated vertical walls in the top support plate. The wearstrips <NUM> can be inserted before or after roller assemblies <NUM>. The drive roller assembly <NUM> is then ready to selectively move the drive rollers <NUM> between diverting positions and a non-diverting position to selectively divert objects on a conveyor belt running over the drive roller assembly <NUM>.

According to another embodiment, the corrugated vertical walls of the top support plate <NUM> may be separate from a main portion of the top support plate to allow retrofitting, replacement and-or cleaning of the corrugated vertical walls, or for another purpose. For example, as shown in <FIG>, a drive roller assembly <NUM> may include a bottom support plate <NUM> and a top support plate <NUM> including openings <NUM> for roller assemblies (not shown, but similar to identical to the roller assemblies <NUM> or <NUM> described above). A corrugated insert <NUM> is inserted between two columns of openings <NUM>, at selected lateral intervals, and includes shaped recesses <NUM> in upper edges of the corrugated insert configured to hold a wearstrip <NUM>.

<FIG> show an embodiment of a corrugated insert <NUM> that may be used with a drive roller assembly to allow the drive assembly to incorporate wearstrips. The illustrative corrugated insert <NUM> includes a base <NUM>, two columns of offset openings <NUM> configured to overlap openings of an upper support plate <NUM> and a corrugated vertical wall <NUM> between the columns. The illustrative openings <NUM> include camming surfaces <NUM> for selectively raising and lowering a drive roller carrier received in an opening <NUM> during pivoting of the drive roller carrier about a vertical axis. The corrugated vertical wall <NUM> includes top recesses <NUM> for receiving a wearstrip <NUM>. The other features of the corrugated vertical wall <NUM>, such as gussets and slots, may be similar to the corrugated vertical wall <NUM> described above. The corrugated insert <NUM> may include connectors, shown a bottom protrusions <NUM>, for connecting the corrugated insert <NUM> to a top support plate to integrate wearstrips into a drive assembly. Other suitable means for integrating the corrugated insert <NUM> may be used.

<FIG> show another embodiment of a corrugated insert <NUM> for a drive assembly to enable insertion of wearstrips across a width of the drive assembly. The corrugated insert <NUM> includes a base <NUM> from which a corrugated wall <NUM> extends. The corrugated wall <NUM> includes upper recesses <NUM> for seating a wearstrip. The illustrative insert <NUM> does not entirely circumscribe the openings <NUM> of the upper support plate <NUM>, but the invention is not so limited. The insert <NUM> further include insertion tabs <NUM> extending from the bottom of the base <NUM> for connecting the corrugated insert <NUM> to a top support plate to integrate wearstrips into a drive system. Gussets, slots and other features may also be included, as described above.

<FIG> show another embodiment of a corrugated insert <NUM> suitable for use with a drive roller assembly <NUM>. The corrugated insert <NUM> comprises a corrugated vertical wall <NUM> extending from a first end to a second end and having curves that partially circumscribe openings in adjacent columns of an upper support plate <NUM> of an underlying drive roller assembly <NUM>. The illustrative insert <NUM> includes one or more circular rims extending from the vertical wall <NUM> defining openings <NUM> that overlap openings <NUM> of an upper support plate <NUM>. The openings <NUM> can include camming surfaces for selectively raising and lowering a drive roller, replacing selected camming surfaces in the upper drive plate, as described above. The corrugated vertical wall <NUM> includes top recesses <NUM> for receiving a wearstrip. Curved gussets <NUM> extend tangentially to the corrugated wall <NUM> to provide additional support and fit between features of the upper support plate of an underlying drive roller assembly that employs the insert <NUM>. The corrugated insert <NUM> may include connectors, shown a bottom protrusions <NUM>, for connecting the corrugated insert <NUM> to a top support plate to integrate wearstrips into a drive assembly. Other suitable means for integrating the corrugated insert <NUM> may be used.

In another embodiment, a translatable orientation device for a drive roller assembly may comprise a compliant mechanism for causing drive roller carriers to pivot about their vertical axes. Referring to <FIG> and <FIG>, a drive mechanism <NUM> including an array of drive rollers for selectively engaging object-carrying rollers in a conveyor belt to selectively effect diversion of objects on the conveyor belt comprises a plurality of pivotable roller carriers <NUM> for housing freely-rotating drive rollers (not shown). A fixed top support sheet <NUM> includes carrier-receiving openings <NUM>, as well as fastener openings <NUM> for connecting the top support sheet <NUM> to a fixed bottom support sheet <NUM>. A translatable orientation device <NUM> is movably sandwiched between the top support sheet <NUM> and the bottom support sheet <NUM>. The translatable orientation device can slide back and forth to selectively pivot the roller carriers about a vertical axis.

The top support plate <NUM> may comprise a planar substrate <NUM> including vertical walls <NUM> having top edges <NUM> extending up from the planar substrate and encircling at least a portion of the openings <NUM>. The openings <NUM> narrow at the bottom to form a shelf <NUM> and a smaller opening <NUM> at the bottom of the top support plate <NUM>, which may be formed of injection-molded plastic or another suitable material.

The illustrative roller carriers <NUM> include a retainer ring <NUM> with diametrically opposite holes <NUM> supporting the ends of an axle of a drive roller. A bottom rim <NUM> of the retainer ring <NUM> rests on the top edge <NUM> of the top support plate1320 and turns thereabout. An upper journal stem <NUM> extends downwards from the retainer ring <NUM> and is seated and pivotable within the openings <NUM>. A downward-extending stem <NUM> extends through the smaller opening <NUM> and is received in a corresponding opening <NUM> in the translatable orientation device <NUM>. The illustrative stem <NUM> has a square or otherwise polygonal cross-section, but the invention is not so limited.

In one embodiment, the bottom rim <NUM> of the retainer ring <NUM> can be shaped with ramp sections and the top edge <NUM> of the top support plate can also be shaped to cause the roller carrier <NUM> to selectively raise and lower the carried drive roller as the roller carrier <NUM> pivots about its vertical axis, as described above.

The illustrative translatable orientation device <NUM> comprises a planar substrate <NUM> including elongated openings <NUM> including a cam mechanism <NUM> connected to a flexible leaf <NUM> that is connected to the main portion of the planar substrate <NUM>. The openings <NUM> in the cam mechanism are sized and shaped to receive corresponding stems <NUM> of the roller carriers. The openings are sized and configured so that rotation of the cam <NUM> pivots the received roller carrier <NUM>. While the illustrative openings <NUM> and associated stems <NUM> are square, the invention is not so limited, and can comprises any geometry that rotationally locks the components together. A boss <NUM> extends downwards from the bottom of the cam and is sized and shaped to be received in openings <NUM> in the bottom support plate.

The translation device <NUM> further includes slots <NUM> to accommodate fasteners connecting the top support plate <NUM> and the bottom support plate <NUM>.

The bottom support sheet <NUM> comprises a planar substrate <NUM> including openings <NUM> for receiving the cam bosses <NUM>. The openings <NUM> may be raised relative to the substrate <NUM>. Bosses <NUM> for receiving fasteners to connect the top and bottom support plate also extend up from the substrate <NUM> and extend through the slots <NUM> and into the fastener openings <NUM> when the assembly is assembled.

An actuator, such as the actuator <NUM> described above or another suitable device, selectively moves the translatable orientation device to orient the roller carriers. The actuator can slide the translatable orientation device back and forth in a linear direction <NUM>, as shown in <FIG>, to pivot the roller carriers. The illustrative cam <NUM> may be fan-shaped, including diverging straight side edges <NUM>, <NUM>, a convex curved back edge <NUM> and a larger convex curved front edge <NUM>, but the invention is not so limited.

In a default orientation, such as that shown in <FIG> and <FIG>, the cam <NUM> is disposed in a first section of the elongated slot <NUM>, with a first side edge adjacent a side edge <NUM> of the elongated slot <NUM> and the opening <NUM> holding the roller carrier <NUM> in a first orientation. In the illustrative first orientation, a corresponding drive roller will roll in direction <NUM>. When the translation device moves in a direction <NUM>, shown in <FIG>, the leaf <NUM>, which connects the cam <NUM> to the plate <NUM>, pushes or pulls on its mating cam <NUM> at its circumference, causing the cam <NUM>, which is fixed laterally by the bottom support plate <NUM>, to rotate. During rotation, the leaf <NUM> wraps around the circumference or front edge <NUM> of the cam <NUM>. In a central orientation, shown in <FIG>, a drive roller will roll in direction <NUM>. The actuator can continue to move the orientation device in direction <NUM> to a fully translated position, shown in <FIG>. In the fully translated position, the second side edge <NUM> of the cam <NUM> abuts a second side edge <NUM> of the elongated slot <NUM>, which places the roller carrier in a third orientation, in which the drive roller rotates in direction <NUM>, which is about <NUM>° rotated left of the first direction <NUM>. The roller orientation can be an infinite gradient between the default orientation and the fully translated orientation. The level of gradation depends only on the actuator type used. For example, a three-position pneumatic actuator assembly can only achieve left, right, and center. But an electric stepper motor with a ball screw could achieve those three positions plus everything in between.

Other suitable means for selectively pivoting the roller carriers may be used.

Claim 1:
A drive roller assembly (<NUM>) for selectively actuating conveyor belt rollers (<NUM>) in a conveyor belt (<NUM>) configured to divert objects atop the conveyor belt rollers (<NUM>) as the conveyor belt (<NUM>) advances along a carryway, the drive roller assembly (<NUM>) comprising:
a plurality of pivotable roller carriers (<NUM>), each carrier (<NUM>) housing a freely rotatable drive roller (<NUM>) that contacts the conveyor belt rollers (<NUM>) from below the conveyor belt (<NUM>);
a translatable orientation device (<NUM>) for engaging the pivotable roller carriers (<NUM>) to change the orientation of the drive rollers (<NUM>) with respect to the conveyor belt rollers (<NUM>); and
an actuator (<NUM>) for selectively moving the translatable orientation device (<NUM>) to pivot the pivotable roller carriers (<NUM>);
characterised in that said drive roller assembly (<NUM>) further comprises a three-dimensional top support plate (<NUM>) including an array of openings (<NUM>) arranged in a quincunx pattern, wherein the roller carriers (<NUM>) extend through the openings (<NUM>), the three-dimensional top support plate (<NUM>) including at least one corrugated vertical wall (<NUM>) extending longitudinally on the top support plate (<NUM>) between a first and second column of openings (<NUM>), each corrugated vertical wall (<NUM>) including a plurality of notches in a top edge for receiving a wearstrip (<NUM>), with each curve in the corrugated vertical wall (<NUM>) partially surrounding an opening (<NUM>).