Patent Description:
The present invention relates to power-driven conveyors. More particularly, the invention relates to drive assemblies for a conveyor to for moving a conveyor belt through a circuit and transitioning conveyed items off of the conveyor.

Power-driven conveyors are used to convey items. Infeed assemblies are used to transition items onto the conveyor as the conveyor belt moves from a returnway to a carryway above the returnway. Outfeed assemblies are used to transition items off of the conveyor as the belt moves from the carryway to the returnway. A drive moves the conveyor belt through the conveying circuit. For example, drive sprockets mounted on a rotatable shaft may engage and drive the conveyor belt along the conveying circuit. Drive sprockets can be located at the outfeed of the conveyor or within the returnway of the circuit. Scrapers can be mounted at the outfeed to remove debris from the conveyor belt before it enters the returnway. Hygiene can pose a problem with conveyors, as dirt, debris, bacteria and other contaminants can become trapped in the different components.

An example of a drive assembly showing the preamble of claim <NUM> is disclosed in <CIT>.

The present invention provides a drive assembly for a conveyor belt in accordance with claim <NUM>.

The present invention provides a sanitary system at a drive end of a conveyor that can be easily installed, moved to a cleaning position, and -or removed. The present invention will be described below relative to an illustrative embodiment. Those skilled in the art will appreciate that the present invention may be implemented in a number of different applications and embodiments and is not specifically limited in its application to the particular embodiments depicted herein.

<FIG> is an isometric view of a drive assembly <NUM> for a conveyor forming an outfeed for a conveyor. The drive assembly <NUM> comprises a pair of opposing end plates <NUM> for mounting a drive axle <NUM> of a reversing element, such as a sprocket or other conveyor drive, for a conveyor belt <NUM> at outfeed end of a carryway, which extends between the pair of end plates <NUM>. The illustrative conveyor belt <NUM> is a positive drive, low tension conveyor belt. Examples of suitable positively-driven, low tension conveyor belts include, but are not limited to: THERMODRIVE® belting, available from Intralox, LLC, of Harahan, LA, USA, the Cleandrive belt available from Habasit AG, the Gates Mectrol PosiClean® belt available from Gates Mectrol, the Volta SuperDrive™ belt and other positive drive belts available from Volta Belting and other positively-driven, low tension conveyor belts known in the art. The illustrative conveyor belt <NUM> has a smooth outer surface substantially free of discontinuities and an inner surface with a plurality of teeth at a given belt pitch or other suitable drive elements. The conveyor belt <NUM> conveys products along the carryway from an infeed to the outfeed and returns along a returnway below the carryway. The conveyor belt <NUM> may include flights or other features and is not limited to the illustrative examples. The end plates <NUM> also mount a scraper assembly <NUM> for cleaning the conveyor belt <NUM>. Side guards <NUM> are mounted to the end plates <NUM> for guarding the edges of conveyor belt <NUM> in the outfeed region and - or containing product on the carryway of the conveyor belt. The illustrative side guards <NUM> also cover the reversing element.

Referring to <FIG>, each end plate <NUM> has a body that extends in height from a top edge <NUM> to a bottom edge <NUM> and in length from a front edge <NUM> to a rear edge <NUM>, which attaches to a back mounting plate <NUM>. An axle opening, shown as a tapering, angled channel <NUM> extending from a wide opening between the top edge <NUM> and the front edge <NUM> and terminating in a seat <NUM> for the axle <NUM> of a motorized sprocket or another reversing element. Alternatively, a bearing assembly may be provided in or integral with the seat <NUM> to house an axle of the sprocket driven by an external motor or other reversing element. A scraper assembly seat <NUM> extends from the bottom of the front edge <NUM>. The illustrative scraper assembly seat <NUM> is an open seat comprising a curved protrusion, but the invention is not so limited. Behind the scraper assembly seat <NUM>, a limiting groove <NUM> is formed in the bottom edge <NUM> for limiting rotation of the scraper assembly away from the belt, as described in detail below. A tensioning lever <NUM>, or other feature, is used to selectively tension and release a tensioning device in the scraper assembly, as described below. The illustrative tensioning lever <NUM> comprises a rounded contact nub <NUM> at the end of a connecting leg <NUM>, which is pivotally connected to a handle <NUM> via a pivot <NUM>. Each end plate <NUM> further includes a shaped recess <NUM> between the top edge <NUM> and rear edge <NUM> for receiving a corresponding shaped pivoting mounting portion of the side guard <NUM>, as described below.

Referring to <FIG>, the scraper assembly <NUM> comprises a substantially cylindrical base <NUM> extending between a pair of opposing scraper mounting plates <NUM>. A scraper blade <NUM> extends up from the base <NUM>. The base includes a reduced-diameter neck portion <NUM> configured to be received in the scraper assembly seat <NUM> for mounting the scraper assembly between two end plates <NUM>. Each scraper mounting plate <NUM> comprises a semicircular front wall <NUM> transitioning to a substantially flat bottom wall <NUM> and a downwardly-angled upper wall <NUM>. A channel <NUM> extends inwards between the flat bottom wall <NUM> and the downwardly-angled upper wall <NUM> for mounting a leaf spring <NUM> or other tensioning element for the scraper assembly <NUM> and forming a pair of legs: upper <NUM> and lower leg <NUM>. The upper leg <NUM> terminates in a downward-extending nub <NUM> for guiding the leaf spring <NUM>. A cylindrical pin <NUM> extends laterally at the end of the lower leg <NUM> for interacting with the groove <NUM> of the end plate <NUM> to limit movement of the scraper assembly <NUM> and forming a pivot point (fulcrum) for the leaf spring <NUM>. The scraper assembly <NUM> further includes a shaped protrusion <NUM> within the channel <NUM> at the outer end of the lower leg <NUM> for mounting the leaf spring <NUM> via an opening <NUM> in the outer end of the leaf spring <NUM>. The top of the shaped protrusion <NUM> is larger than the opening to restrain the leaf spring <NUM>, then the body of the shaped protrusion <NUM> tapers towards the lower leg <NUM> to allow sliding of the leaf spring outer end over the shaped protrusion. The illustrative leaf spring <NUM> deforms in order to mount the leaf spring <NUM> over the shaped protrusion <NUM>, and may require a tool to mount and - or detach the spring leaf from the scraper mounting plate <NUM>. When mounted to the scraper mounting plate <NUM>, the elongated leaf spring <NUM> extends inwards, away from the scraper blade <NUM>. The leaf spring is thus easily replaceable, repairable and adjustable, and provides a reliable, consistent and cleanable tensioning mechanism for ensuring proper contact between the scraper blade and the conveyor belt.

Referring to <FIG>, in a tensioned position, the leaf spring <NUM> applies torque to the scraper assembly <NUM>. In the tensioned position, the inner end <NUM> of the leaf spring is pushed down, so that the leaf spring <NUM> pivots down about the pin <NUM>, pushing the outer end containing the opening <NUM> up and pulling the scraper mounting plate <NUM> up. The shaped protrusion <NUM> and downward-extending nub <NUM> constrain the upper movement of the outer end of the leaf spring.

As shown in <FIG>, in an untensioned position, for example, when the scraper assembly <NUM> is removed, the outer end of the leaf spring <NUM> can sit the bottom of the shaped protrusion <NUM>, which extends through the opening <NUM>, the body of the leaf spring <NUM> spaced from the downward-extending nub <NUM> and an inner portion of the body resting on the pin <NUM>. With no pressure applied to the leaf spring, the spring is loosely held and able to move away from each contact point with little force for easy cleaning.

<FIG> show the blade <NUM> and scraper base <NUM> of the scraper assembly <NUM>. The blade <NUM> can be easily and removably mounted to the scraper base <NUM> without tools. The blade <NUM> comprises a tapering body <NUM> terminating in a pointed tip <NUM>, which, in an operational position, is biased against the conveyor belt <NUM> to remove debris from the conveyor belt surface. The illustrative scraper blade <NUM> also provides a continuous force on the conveyor belt to ensure proper engagement between the drive elements on the conveyor belt and drive. As shown in <FIG>, the illustrative blade body <NUM> has a shape of an angled triangle. In another embodiment, the blade body <NUM> has a different shape, such as a tapering lower portion and a tapering upper portion extending at an angle relative to the tapering lower portion. The blade body <NUM> may have a consistent width, or may taper in both width and thickness towards the edge <NUM>. The blade <NUM> further includes mounting tabs <NUM> extending down from the bottom of the tapering blade body <NUM>. The corresponding scraper base <NUM> includes a series of openings, shown as channels <NUM>, configured to receive the mounting tabs <NUM> to mount the blade <NUM> to the scraper base. The illustrative openings <NUM> include a central bend or curve <NUM>, shown in <FIG> to facilitate a tight grip on the mounting tabs <NUM> when inserted in the base openings <NUM>. The central bend or curve <NUM> ensured three points of pressurized contact between the mounting tab <NUM> and the channel <NUM>, while the dimensions of the channel <NUM> are configured to ensure sufficient clearance to accommodate a wide tolerance range for the scraper blade <NUM>. The width of each illustrative channel <NUM> is wider than the thickest mounting tab <NUM>, but the difference between the straight edge of the channel <NUM> and the end of the bend is less than the thinnest toleranced scraper mounting tab <NUM>. Alternatively, a single serpentine channel across the length of the base <NUM> may be used, or other configurations for the channel may be used.

As shown in <FIG>, each mounting tab <NUM> includes a rounded recess <NUM> between the blade body <NUM> and the mounting tab <NUM> to facilitate cleaning, though the rounded recess <NUM> can have other shapes, sizes and configurations, or be omitted entirely. When inserted in the base <NUM>, the bottom of the blade body <NUM> rests on the top of the base <NUM>, as shown in <FIG>.

Referring to <FIG>, in the operational position, the tensioning lever <NUM> is positioned so that the contact nub <NUM> contacts and pushes the inward end <NUM> of the leaf spring <NUM> down to tension the leaf spring <NUM>. The downward force on the inward end <NUM> of the leaf spring <NUM> rotates the outer end of the leaf spring <NUM> up against the protrusion <NUM>, rotating the scraper mounting plates <NUM> up, so that the blade tip <NUM> pushes against the conveyor belt <NUM>. Thus, the tensioned leaf spring <NUM> causes the scraper blade tip <NUM> to be held with pressure against the conveyor belt <NUM>.

<FIG> shows the drive unit <NUM> during release of the tensioning lever <NUM> to remove the tension in the leaf spring <NUM>. The tensioning lever <NUM> can rotate clockwise about the pivot <NUM>, which moves the contact nub <NUM> up and outward, releasing the tension from the leaf spring <NUM> and allowing the scraper blade tip <NUM> to pivot away from the conveyor belt <NUM>. In the illustrative embodiment, the rotation of the scraper assembly away from the conveyor belt is limited by an interference between the pin <NUM> and the groove <NUM> in the end plate <NUM>, shown in <FIG>. The amount of allowable movement can be adjusted by modifying the dimensions, location or configuration of the interfering components.

In another embodiment, the tensioning lever <NUM> may also serve to push the scraper assembly out of engagement with the conveyor belt. For example, the scraper mounting plate <NUM> may include a protrusion or other feature designed to engage the tensioning lever <NUM>, which is designed to contact the scraper mounting plate <NUM> when rotated to both release tension and rotate the scraper mounting plate <NUM> within the saddle <NUM>.

Referring to <FIG>, the illustrative drive assembly <NUM> includes side guards <NUM> that can be easily integrated into the drive assembly <NUM> and removed for cleaning or another purpose. Each illustrative side guard <NUM> comprises a shaped block of UHMW (Ultra High Molecular Weight Polyethylene), or another low-friction material forming a main rail <NUM> disposed adjacent the carryway prior to the sprocket <NUM>, a shaped mounting portion <NUM> at an inner end of the main rail <NUM>, a front rail <NUM> curving and extending down and forward from the front end of the main rail <NUM> and terminating in a locking portion <NUM>. The shaped mounting portion <NUM> is configured to be received in, and pivot about, the shaped recess <NUM> in the end plate <NUM> to mount the side guard to the drive assembly <NUM>. The front rail <NUM> covers the front wall <NUM> of the corresponding end plate <NUM> when the drive assembly <NUM> is assembled, as shown in <FIG>. A tapering inward projection <NUM> extends radially inward from the curve at the interface of the main rail <NUM> and the front rail <NUM>, fitting in the tapering channel <NUM> of the end plate <NUM> and terminating in a block <NUM> that fits above the seat <NUM> for the axle <NUM>, thereby covering the exposed portion of the sprocket <NUM>. The side guards <NUM> can have any suitable size, shaped and configuration depending on the particular configuration of the end plates <NUM>. In another embodiment, a separate pivot point for pivotally mounting the side guard <NUM> to the end plate <NUM> may be used, for example, a pin extending from the end plate that is received in an opening in the side guard.

Referring to <FIG>, the illustrative locking portion <NUM> includes an opening <NUM> for receiving a lock <NUM>, shown as an embedded bolt having a head <NUM>, shank <NUM> and end threaded portion <NUM> received in an opening in the wall <NUM>. The threaded portion <NUM> is wider than the shank portion <NUM> and the opening <NUM> varies in sizes to accommodate the different widths, and to capture the bolt in the locking portion <NUM>. After inserting the shaped mounting portion <NUM> in the shaped recess <NUM>, the rail <NUM> is rotated about the pivot point formed by the shaped mounting portion <NUM>, so that the rail <NUM> overlies the top edge <NUM> of the end plate, the taping inward projection <NUM> is inserted in the tapering channel <NUM>, the front rail <NUM> overlies the front wall <NUM> and the opening <NUM> aligns with a locking opening in the front wall. Then the bolt is turns to insert the threaded portion <NUM> of the bolt <NUM> into the capturing opening. In one embodiment, securing the side guard <NUM> in position also blocks the scraper assembly <NUM> and prevents it from exiting the seats <NUM>. The shank <NUM> may also include a threaded portion that mates with a threaded portion in the opening <NUM>.

<FIG> is a cross sectional view of the interface between the main rail <NUM> of the side guard <NUM> and an end plate <NUM>. The illustrative main rail <NUM> includes a channel <NUM> that receives a flange <NUM> on an inner side of the top edge <NUM> of the end plate <NUM> to constrain the lateral movement of the side guard <NUM>. The illustrative main rail <NUM> has a substantially rectangular cross-section, and inner end of which covers the edge of the conveyor belt. The channel <NUM> is formed in the bottom surface of the main body of the rail and a lower protrusion187 extends alongside the inner wall of the end plate <NUM>, between the end plate and the edge of the conveyor belt <NUM>.

<FIG> show a drive assembly <NUM> for a conveyor according to another embodiment. While the scraper assembly <NUM> is the same as the scraper assembly <NUM> in <FIG>, the means for applying tension to the leaf spring <NUM> is different. The illustrative drive assembly <NUM> includes a tensioning post <NUM> extending from the end plate <NUM> near the intersection of the bottom edge and the rear edge. As soon as the scraper assembly <NUM> is seated in the scraper assembly seats <NUM>, in <FIG>, the spring leaf <NUM> is tensioned by the tensioning post <NUM>, without requiring additional steps. As shown in <FIG>, side guards <NUM> can be mounted to the drive assembly <NUM> after seating the scraper assembly. The mounted side guards <NUM> prevent removal of the scraper assembly <NUM> from the seats <NUM>.

In another embodiment, shown in <FIG>, a tensioning device for a leaf spring <NUM> in a scraper assembly <NUM> for a drive assembly <NUM> may comprise a catch plate <NUM> extending up and outward from a tensioning post <NUM> at an angle to guide the end of the leaf spring <NUM> into the tensioning position, shown in <FIG>, when the scraper assembly <NUM> is inserted in scraper assembly seats <NUM>.

<FIG> show another embodiment of a drive assembly <NUM> for a conveyor, including a position limiter for ensuring proper engagement between drive elements on a conveyor belt <NUM> and a conveyor drive, such as a sprocket <NUM>. The illustrative position limiter is a roller limiter <NUM>, but can alternatively be a full-width non-roller position limiter, a series of individual position limiters or any other suitable type of position limiter. The drive assembly <NUM> comprises a pair of opposing end plates <NUM> connected by a transverse mounting plate <NUM> for mounting or integrating a bearing <NUM> rotatably housing drive axle <NUM> of a reversing element, such as the sprocket <NUM>, for a conveyor belt <NUM> at outfeed end of a carryway, which extends between the pair of end plates <NUM>. The end plates <NUM> also mount a limiter-scraper assembly <NUM> for mounting both the roller position limiter <NUM> and a scraper assembly for cleaning the conveyor belt <NUM>. <FIG> shows the drive assembly <NUM> with the scraper blade removed, and <FIG> shows the scraper blade <NUM> mounted in the limiter-scraper assembly <NUM>. Side guards <NUM> are mounted to the end plates <NUM> for guarding the edges of conveyor belt <NUM> in the outfeed region and - or containing product on the carryway of the conveyor belt.

The drive assembly <NUM> may further include a chute <NUM>, shown in <FIG>, mounted to the end plates <NUM> for receiving product discharged from the conveyor belt <NUM>.

<FIG> shows the limiter-scraper assembly <NUM> of <FIG> and <FIG> including a scraper blade <NUM> mounted to a base <NUM> extending between scraper mounting plates <NUM> mounted to assembly mounting arms <NUM>. The assembly mounting arms <NUM> are mounted to the outsides of the end plates <NUM> to mount the scraper assembly and position limiter and scraper assembly to the drive assembly <NUM>. The scraper mounting plates <NUM> are similar to the scraper mounting plates <NUM> described above, and each mount a leaf spring <NUM> for biasing the scraper blade <NUM> into engagement with the conveyor belt. The roller limiter <NUM> extends between the assembly mounting arms <NUM>, which includes openings <NUM> for receiving bearings <NUM>, as shown in <FIG>, so that the roller limiter <NUM> can rotate relative to the assembly mounting arms <NUM>. As shown in <FIG>, the roller limiter <NUM> may including tapered ends <NUM>.

<FIG> is a detailed view of an assembly mounting arm <NUM> of an embodiment of the invention. The assembly mounting arms <NUM> may accurately hold the roller limiter and - or scraper in operational and cleaning positions relative to the conveyor drive, allowing movement between these two positions, as well as removal from the conveyor frame without the use of tools. The illustrative assembly mounting plate <NUM> includes a lower mounting portion <NUM> including the opening <NUM> for receiving bearing <NUM>. Extending rearward from the lower mounting portion <NUM> are one or more fingers <NUM>, an upper finger <NUM> terminating in an outward facing stop <NUM>, shown as a squarish protrusion extending laterally outward from a connecting portion <NUM> that forms a recess. The lower mounting portion <NUM> further includes a saddle <NUM> at a front end for mounting the scraper assembly <NUM>. The illustrative saddle <NUM> comprises converging legs <NUM>, <NUM> forming a shaped opening <NUM> for receiving the base <NUM> of the scraper. The shaped opening <NUM> includes an upper cylindrical portion intersection a lower cylindrical portion, allowing the scraper base <NUM> to travel within the opening <NUM>, while preventing escape of the base <NUM> without intentional effort. For example, in a cleaning position, when the assembly mounting arm <NUM> is inverted, as described below, the scraper base <NUM> can fall from the first leg <NUM> to the second leg <NUM> allowing cleaning of the first leg <NUM>, in which the scraper base <NUM> is normally held.

A shaped arm extends up from the lower mounting portion <NUM> and includes a lower curved portion <NUM> and terminates in an upper latch <NUM>. The lower curved portion <NUM> includes a narrowed portion <NUM> that may include a hole, designed as a designated fail point, allowing the assembly mounting arm <NUM> to break, bend or otherwise deform out of the way before other components in the assembly if excessive forces are applied to the arm, preventing catastrophic failure. A shaped nose <NUM> protrudes forward from the top of the narrowed portion <NUM>, and a pivot arm <NUM> extends laterally outwards between the shaped nose and narrowed portion <NUM>. The upper latch <NUM> forms a key-hole opening <NUM> having a narrowed opening formed by substantially straight side walls <NUM>.

Referring back to <FIG> and also to <FIG>, the end plates <NUM> include mounting features for mounting the limiter-scraper assembly <NUM>. The illustrative end plates <NUM> include an upper mounting protrusion <NUM> for receiving the upper latch <NUM> and a lower protrusion <NUM> forming a stop. The upper mounting protrusion includes flat slides and a rounded top and bottom and is designed to be received in the upper latch <NUM>, so that the mounting arm <NUM> can rotate about the upper protrusion without removal from the assembly. As shown in <FIG> and <FIG>, when in an operating position, the stop <NUM> of the limiter-scraper assembly <NUM> abuts the lower protrusion <NUM> of the end plate <NUM> to place the roller limiter and scraper blade in proper position relative to the conveyor belt <NUM>. The lower protrusion <NUM> of the end plate <NUM> may include a latching arm <NUM> designed to receive and latch onto the stop <NUM>, fitting into a space formed between the stop <NUM> and connecting portion <NUM>. In one embodiment, the lower protrusion <NUM> can rotate to move the latching arm <NUM> into and out of engagement with the stop <NUM>. The leaf spring <NUM> also abuts the lower protrusion <NUM> and rests above the stop <NUM>. The end of the leaf spring <NUM> bends down, so that engagement with the lower protrusion <NUM> biases the scraper blade into engagement with the conveyor belt. Or, the leaf spring <NUM> may extend below the protrusion <NUM> to bias the leaf spring. The limiter-scraper assembly <NUM> can rotate about the upper mounting protrusion <NUM> to place the assembly in a cleaning position, with the scraper blade and roller limiter moved away from the conveyor belt.

In another embodiment, shown in <FIG>, the drive assembly <NUM> may include a shaped handle <NUM> pivotally connected to an assembly mounting arm <NUM> at a pivot point <NUM> near the nose <NUM>. The shaped handle <NUM> is also pivotally connected to a lower protrusion <NUM> of the end plate <NUM>. In the operating position, shown in <FIG>, the handle <NUM> is pushed down, with a lower end of the handle applying pressure to the leaf spring <NUM> to bias the scraper blade into position. The handle <NUM> also rotates the lower protrusion <NUM> into position so that the connected latching arm <NUM> latches onto the stop <NUM>. The shaped handle <NUM> may include a spring tab <NUM> for connecting the shaped handle to the assembly mounting arm pivot point <NUM>, shown as a pin extending from the assembly mounting arm <NUM>. The spring tab <NUM> prevents the handle <NUM> from moving out of the operating position without intentional effort.

The handle <NUM> can be pulled back, rotated about lower protrusion <NUM>, as shown in <FIG>, to release the stop <NUM> from the latching arm <NUM>, pivot the limiter-scraper assembly <NUM> up about upper protrusion <NUM> and out of the operating position and into a cleaning position, also untensioning the leaf spring <NUM>. The handle <NUM> can be used to disengage the scraper from the belt without moving the arm assembly fully into the cleaning position. The illustrative handle is connected to both assembly mounting arms <NUM> via a torsion bar extending between the end plates <NUM>, so that the assembly can be moved between the operating and locking positions from a single side of the conveyor. The torsion bar, which terminates in protrusions <NUM> extending from each end plate <NUM>, sides in a saddle formed in the end plates, and may be inserted via a slot. A bolt or other fastener may lock the torsion bar in position.

Referring to <FIG>, in one embodiment, the handle <NUM> may be connected to or integral with a spray bar <NUM> for cleaning the conveyor belt. The spray bar <NUM> may extend between the mounting plates <NUM> to form the torsion bar described above, and includes nozzles <NUM> connected to a cleaning fluid source for spraying cleaning fluid on the conveyor belt within the drive assembly <NUM>.

Referring to <FIG>, in one embodiment, the drive assembly <NUM> may include a guard <NUM> to protect a pinch point between the roller limiter <NUM> and the conveyor belt <NUM>, providing stability for the system while guarding the roller limiter <NUM>. The illustrative guard <NUM> may extend between and be mounted to the opposing assembly mounting arms <NUM>. The illustrative guard comprises a curved sheet <NUM> extending from a first side to a second side. On each side, an upper connecting tab <NUM> includes an opening for receiving a fastener <NUM> to fasten the guard to an inner surface of the assembly mounting arm <NUM>. Each side of the guard <NUM> further includes a bent lower connecting tab <NUM> including an opening for receiving another fastener <NUM> to fasten the guard <NUM> to a lower edge of the assembly mounting arm <NUM>.

As previously described, the drive assembly <NUM> may include a chute <NUM> for receiving product offloaded at the drive end of a conveyor employing the drive assembly <NUM>. Referring to <FIG>, the illustrative chute <NUM> includes a planar slide portion <NUM> having side walls <NUM> and connecting arms <NUM> for attaching the chute to the end plates <NUM>. When attached, the planar slide portion <NUM> of the chute extends from the end plates <NUM> and rests under the scraper mounting bar <NUM>, so that the limiter-scraper assembly can be rotated into a cleaning position while the chute is still attached to the end plates <NUM>. Each connecting arm <NUM> includes an upper connecting portion <NUM> having two seats <NUM>, <NUM>, each configured to receive a connecting pin <NUM>, <NUM> on an end plate <NUM>. As shown in <FIG>, the chute connecting arms <NUM> further include a lower portion <NUM> comprising a planar portion <NUM> connected to the main body of the chute connecting arm <NUM> and terminating in an upward extending tab <NUM>. The illustrative tab <NUM> forms a contact point with the limiter-scraper connecting arm <NUM>. When the limiter-scraper assembly <NUM> is in an operational position, the limiter-scraper connecting arm <NUM> tensions the chute and locks it into position to reduce vibration. The chute <NUM> can have any suitable means for interfacing with a limiter-scraper assembly. The tab <NUM> can alternatively extend laterally from a portion of the chute <NUM> to contact an associated portion of a limiter-scraper assembly. The weight of the chute <NUM> holds the chute against the connecting pins <NUM>, <NUM>. Any suitable means for connecting a chute to a drive assembly in a conveyor may be used.

A chute for a drive assembly may be located at any suitable location. For example, the chute <NUM> of <FIG> is located below a scraper assembly. Alternatively, the chute <NUM> may be located at any suitable location relative to a conveyor belt. For example, as shown in <FIG>, a chute <NUM> may be located above a scraper. In the illustrative embodiment, a limiter-scraper assembly <NUM>' may include a cover plate <NUM> to extend the slide portion <NUM> of the chute <NUM> above the scraper. The illustrative cover plate <NUM> may be rotated back or otherwise moved to allow the limiter-scraper assembly <NUM>' to move to a cleaning position when needed.

<FIG> show another embodiment of a drive assembly <NUM> for a conveyor, including mounting assemblies, shown as pillow block bearing housings <NUM>, for receiving a bearing for a roller limiter and including an integral scraper saddle. Each bearing housing <NUM> comprises a mounting portion <NUM>, for mounting the bearing housing to an end plate <NUM> of a drive assembly, a bearing opening <NUM> for receiving a bearing <NUM> for a roller limiter, and a front saddle <NUM> for receiving a base <NUM>' of a scraper assembly <NUM>', the components of which are the same as the scraper assembly <NUM> described above. The mounting portion <NUM> joins to a bottom surface <NUM> of the mounting plate using fasteners, shown as bolts <NUM>, but can alternatively join to another surface of the end plates. In one embodiment, the bolts <NUM> have two sets of threads and the openings in the mounting portion <NUM> and the bottom surface <NUM> are threaded to mate with each set of threads. In another embodiment, the bolts <NUM> are sealing bolts that include one or more sealing washers to seal the interfaces between the bolt <NUM> and the mounting assembly and the end plates <NUM>.

In another embodiment, shown in <FIG>, a drive assembly <NUM> includes opposing end plates <NUM> connected by a transverse mounting plate <NUM> and including mounting assemblies, shown as position limiter mounting plates <NUM>, attached to the outside surface of the end plates <NUM>. The illustrative position limiter mounting plates <NUM> extend below each end plate <NUM> for mounting one or more snap-on position limiters <NUM>. The position limiters <NUM> ensure proper engagement between drive structure on a conveyor belt and drive structure on a sprocket <NUM> or other drive element. Each end plate <NUM> includes an opening <NUM> receiving a bearing <NUM> for rotatably housing a drive axle <NUM> of the sprocket <NUM> or other drive element.

Each illustrative limiter mounting plate <NUM>, as shown in <FIG> and <FIG>, comprises a planar plate tapering in length from a concavely curved top surface <NUM>, to accommodate the bearing <NUM> and drive axle <NUM>, to a flat bottom surface <NUM>. The illustrative position limiter mounting plate <NUM> has a consistent width, but the invention is not so limited. An upper portion of the plate forms a connection portion for mounting the limiter mounting plate <NUM> to an outer surface of the associated end plate <NUM>. The illustrative connection portion includes offset openings <NUM>, <NUM> for receiving fasteners <NUM>, <NUM> that can be inserted through the limiter mounting plate <NUM> and into corresponding openings in the end plate <NUM>. The fasteners <NUM>, <NUM> may comprise bolts having integrated sealing washers. The connecting portion further includes offset pins <NUM>, <NUM> that can be used to mount a chute or other additional feature. As shown, an outer end of the connecting portion includes a fastener opening <NUM> on top and a pin <NUM> below the fastener opening <NUM>, while the inner end of the connecting portion includes a pin <NUM> on top and a fastener opening <NUM> below the nub <NUM>, but the invention is not so limited. Below the connecting portion, a position limiter mounting bar <NUM> extends laterally inwards from the planar plate. The illustrative position limiter mounting bar <NUM> includes a lateral channel <NUM> and an axial notch <NUM> for receiving a tip and locking tab of the position limiter <NUM> secure the position limiter both axially and laterally on the position limiter mounting bar <NUM> in an operational position, but any suitable means for securing the position limiter <NUM> to the mounting bar <NUM> may be used.

As shown in <FIG>, when assembled, the front edge of the position limiter <NUM> protrudes beyond the front edge of the position limiter mounting plate <NUM>, with a limiting surface of the position limiter adjacent to a conveyor belt driven by the sprocket <NUM>.

In addition, protrusions <NUM> may extend from the back plate <NUM> for preventing backbend of the conveyor belt.

The illustrative drive assembly <NUM> positions each position limiter <NUM> at a side edge of the conveyor belt, with open space therebetween, to accommodate a conveyor belt with flights in the middle portion of the conveyor belt, but alternatively, the mounting bar <NUM> may extend across the width of the drive assembly to accommodate a series of spaced apart snap-on position limiters <NUM> across the width of the drive assembly.

Referring to <FIG>, another embodiment of a drive assembly <NUM> includes mounting assemblies, shown as bearing housings <NUM> fastened to the outside of end plates <NUM> for mounting a roller limiter <NUM> and a scraper assembly <NUM>. The end plates <NUM> extend between a laterally-extending back-mounting plate <NUM>. A sprocket <NUM> or other drive or reversing element is mounted between the end plates <NUM> using bearings in openings in the end plates <NUM>, as described above.

Belt wrap prevention bars <NUM> may extend from the back plate <NUM> for preventing the belt teeth from catching on a frame member and getting sucked back into the drive sprocket, but the invention is not limited to including the belt wrap prevention bars <NUM>.

The illustrative scraper assembly <NUM>, shown in <FIG> includes a substantially cylindrical base <NUM> with tapered ends and cylindrical mounting nubs <NUM> extending between a pair of opposing scraper mounting plates <NUM>. A scraper blade <NUM> extends up from the base <NUM>, similar to the scraper assembly embodiments described above. The scraper plates <NUM> each include an opening <NUM> for receiving a protrusion on the cylindrical mounting nubs <NUM> to mount the cylindrical base <NUM> to the scraper plates. Each scraper mounting plate <NUM> includes a channel <NUM> between upper and lower legs, as described above, for mounting a leaf spring <NUM> or other tensioning element for the scraper assembly <NUM>. A cylindrical pin <NUM> extends laterally at the end of the lower leg to limit movement of the scraper assembly <NUM> and forming a pivot point (fulcrum) for the leaf spring <NUM>. The illustrative cylindrical base <NUM> will be positioned below the leaf spring <NUM> in the embodiment of <FIG>.

In the illustrative embodiment, a handle <NUM> extends up from the scraper mounting plate <NUM> for moving the scraper assembly manually forward for cleaning a certain amount, while keeping the leaf spring <NUM> within its elastic limits.

Referring to <FIG>, the bearing plates <NUM> each include a mounting portion for mounting the bearing plate to an outside surface of an associated end plate <NUM>, as described below, a bearing opening <NUM> for receiving a bearing of the roller limiter <NUM> to rotatably mount and position the roller limiter <NUM> relative to the sprocket <NUM>, and a saddle <NUM> for receiving the cylindrical mounting nub <NUM> of the scraper assembly <NUM> to position the scraper blade <NUM> relative to the sprocket <NUM>.

<FIG> show the bearing plate <NUM> in detail, showing the saddle <NUM> and bearing opening <NUM>. The connecting portion comprises offset openings <NUM>, <NUM> for receiving fasteners (<NUM>, <NUM> in <FIG>) that can be inserted through the bearing plate <NUM> and into corresponding openings in the end plate <NUM>. The fasteners <NUM>, <NUM> may comprise sealing bolts including sealing washers that seal the interfaces between the fasteners and joined components. The illustrative connecting portion further includes offset pins <NUM>, <NUM> that can be used to mount a chute or another element, but the bearing plate <NUM> does not require the offset pins <NUM>, <NUM>. The bearing plate <NUM> also includes a curved upper surface <NUM> to accommodate a sprocket bearing or opening in the end plate <NUM>. The bearing opening <NUM> can include recesses <NUM> to facilitate insertion and removal of a bearing holding the ends of the roller limiter <NUM>. The bearing plate <NUM> further includes an outward-extending tensioning post <NUM> for tensioning the leaf spring <NUM> of the scraper assembly to push the scraper blade <NUM> into proper position relative to the sprocket <NUM> and conveyor belt. When the scraper assembly <NUM> is inserted into the saddles <NUM>, the leaf spring <NUM> extends under the tensioning post <NUM>, pulling the leaf spring <NUM> opposite end up and pushing the scraper blade <NUM> into an operational position.

A channel <NUM> on the outside surface of the bearing plate <NUM> can receive the cylindrical pin <NUM> of the scraper assembly <NUM> to ensure that, when in position, the scraper cannot be forced too far open such that it would move the leaf spring <NUM> past its yield.

<FIG> show another embodiment of a drive assembly <NUM> suitable for a flighted conveyor belt and including mounting assemblies, shown as position limiter plates <NUM>, mounted to the outside surfaces of each end plate <NUM> for mounting a position limiter assembly <NUM> relative to a sprocket <NUM> or other drive element. The illustrative position limiter assembly <NUM> comprises spaced-apart snap-on position limiters <NUM> for ensuring proper engagement between drive structure on a conveyor belt and drive structure on a sprocket <NUM> or other drive element.

As shown in <FIG> and <FIG>, each position limiter plate <NUM> comprises a planar plate in length from a concavely curved top surface <NUM> to a flat bottom surface <NUM>. The illustrative limiter mounting plate <NUM> has a consistent width, but the invention is not so limited. An upper portion of the plate forms a connection portion for mounting the limiter mounting plate <NUM> to an outer surface of the associated end plate <NUM>. The illustrative connection portion includes offset openings <NUM>, <NUM> for receiving fasteners <NUM>, <NUM> that can be inserted through the limiter mounting plate <NUM> and into corresponding openings in the end plate <NUM>. The fasteners <NUM>, <NUM> may be sealing bolts including sealing washers for sealing the interfaces between the fasteners and joined components. The connecting portion further includes offset pins <NUM>, <NUM> that can be used to mount a chute or other additional feature. Below the connecting portion, an opening <NUM> for mounting the position limiter assembly <NUM> extends through the position limiter plate <NUM>. The illustrative opening <NUM> comprises an upper, substantially quadrilateral-shaped portion with a chamfered edge and a lower-portion in the shape of a rounded slot extending substantially perpendicular to and intersecting the upper portion.

Referring to <FIG>, the illustrative position limiter assembly <NUM> comprises a lateral support bar <NUM> including vertical mounting bars <NUM> having cylindrical nubs <NUM> on top thereof, which include outward-extending mounting tabs <NUM> configured to be received in the position limiter plate opening <NUM>. The lateral support bar <NUM> further includes a series of spaced apart vertical limiter bars <NUM> that terminate in position limiter mounting nubs <NUM> that include features for mounting the position limiters <NUM>. The space between the position limiters <NUM> can accommodate flights on a conveyor belt used with the drive assembly <NUM>. In one embodiment, each position limiter mounting nub <NUM> includes a lateral channel and an intersecting axial notch to receive a tip and locking tab of the position limiter <NUM>, but any suitable means for securing a position limiter to the limiter mounting nub <NUM> may be used.

Referring to <FIG>, the illustrative drive assemblies are not limited to the scraper assemblies described above. <FIG> show another embodiment of a scraper assembly <NUM> for a conveyor drive assembly including a pair of leaf springs <NUM> for biasing a scraper blade tip <NUM> into contact with a conveyor belt. Each leaf spring <NUM> is mounted to a mounting base <NUM> extending from a mounting plate <NUM>. A scraper base <NUM> with a narrowed neck portion <NUM> extends between the mounting plates <NUM> and mounts a scraper blade <NUM>. A sealing bolt <NUM> mounts the forward end of the leaf spring <NUM> to the base <NUM>. A relatively wide portion of the leaf spring <NUM> rests on a rounded lip <NUM> that forms a fulcrum point for the leaf spring <NUM>. The rounded lip <NUM> is formed in a recess of the mounting base <NUM> for receiving and seating the widened portion of the leaf spring <NUM>.

As shown in <FIG>, the sealing bolt <NUM> including an upper sealing washer <NUM> between the upper interface of the leaf spring and the bolt head and a lower sealing washer <NUM> between the bottom of the leaf spring, bolt shank and mounting base <NUM>.

The scraper assembly <NUM> can be used with any drive assembly, such as those described above, using a biasing mechanism on the leaf spring <NUM> to selectively bias the scraper blade tip <NUM> into position relative to a conveyor belt used with the drive assembly.

Referring to <FIG>, in another embodiment, a scraper assembly <NUM> for a conveyor belt drive assembly, such as those described above, includes a leaf spring <NUM> mounted to a shaped mounting base <NUM> using a sealing bolt <NUM>, as described above. The mounting base <NUM> includes a top channel <NUM> separating a rounded lip <NUM> forming a fulcrum for the leaf spring <NUM> from the opening for the sealing bolt <NUM>. In addition, a central protrusion <NUM> extends up from the rounded lip <NUM>, aligned with the sealing bolt <NUM>, and is received in a slot <NUM> in the leaf spring <NUM> to maintain the lateral position of the leaf spring on the mounting base <NUM>. Other suitable means for containing the leaf spring may be used. The other components of the illustrative scraper assembly <NUM> are similar to the components of mounting spring <NUM>.

In another embodiment, shown in <FIG>, a scraper assembly <NUM> for a drive assembly, such as a drive assembly as described above, includes a dumbbell-shaped protrusion <NUM> extending from a side of a mounting plate <NUM>. The dumbbell-shaped protrusion <NUM> forms a fulcrum point for a leaf spring <NUM> used to bias a scraper blade into a scraping position relative to a conveyor belt driven by the drive assembly, and also constrains the leaf spring <NUM> between the two end bulges. A shaped mounting portion <NUM> includes an opening for receiving a sealing bolt <NUM>, such as the sealing bolt <NUM> and sealing washers described above, to fasten the leaf spring <NUM> to the scraper assembly <NUM>.

In still another embodiment, shown in <FIG>, a scraper assembly <NUM> includes a dumbbell-shaped protrusion <NUM> for seating and providing a fulcrum for a leaf spring <NUM> and a sealing bolt <NUM> in a shaped mounting portion <NUM>, both extending from a side of a mounting plate <NUM>. The illustrative shaped mounting portion <NUM> extends downwards, trapping the end of the leaf spring between the dumbbell-shaped protrusion <NUM> and shaped mounting portion <NUM>, with the sealing bolt <NUM> below the shaped mounting portion <NUM>.

According to still another embodiment, shown in <FIG>, a drive assembly <NUM> includes an air-actuated tensioning device <NUM> for a scraper assembly <NUM>. The tensioning device <NUM> can move the scraper assembly <NUM> between an operating position, in which the scraper blade <NUM> is biased into contact with the conveyor belt <NUM>, and a cleaning position, in which the scraper blade <NUM> is pushed out of contact with the conveyor belt <NUM>. The scraper assembly <NUM> can be easily removed from the drive assembly <NUM> without requiring tools. The tensioning device <NUM> includes a leaf spring <NUM> mounted to a transverse mounting plate <NUM>, an air cylinder <NUM> mounted to the end of the leaf spring <NUM> and end plate <NUM> and having a piston <NUM> connected to an eccentric scraper mounting plate <NUM>. To bias the scraper blade <NUM> into contact with the conveyor belt, the air cylinder <NUM> pushes the piston <NUM> forward, causing the eccentric scraper mounting plate <NUM> to rotate and push the blade <NUM> into contact with the conveyor belt <NUM>. The piston <NUM> retracts to pull the scraper blade <NUM> away from the conveyor belt.

Claim 1:
A drive assembly (<NUM>) for a conveyor belt (<NUM>), comprising
a pair of opposing end plates (<NUM>);
a drive mounted to and extending between the pair of opposing end plates (<NUM>); and a limiter-scraper assembly (<NUM>) mounted to the pair of opposing end plates (<NUM>), the limiter-scraper assembly (<NUM>) including opposing assembly mounting arms (<NUM>) for mounting a position limiter (<NUM>) and a scraper assembly therebetween, each assembly mounting arm (<NUM>) including a lower mounting portion (<NUM>) including an opening (<NUM>) for a position limiter bearing (<NUM>), the drive assembly (<NUM>) being characterized by a front saddle (<NUM>) for a scraper assembly and a rear-facing finger (<NUM>) terminating in an outward-facing stop (<NUM>) for latching the assembly mounting arm (<NUM>) to an end plate (<NUM>).