Patent Description:
The present invention to transport and accumulation conveyors that support articles on rollers driven by a padded chain or linear belt, and more particularly to a conveyor section.

Powered roller conveyor systems are used in the material handling system to convey articles such as products in totes or cartons through a material handling system. A drive belt or chain can be used to turn rollers that provide the support surface for the articles. One generally-known accumulation and transportation conveyor uses a drive belt that longitudinally underlies the roller that are oriented transverse to the longitudinal axis of the conveyor. This generally-known belt-drive roller conveyor has an elongate transverse cross section with a thin vertical cross section. Thus, the section of conveyor served by such a particular belt is necessarily straight or nearly straight. At each end of the section, the upper portion of the belt by a pulley having a horizontal, transverse axis guiding the remainder of a belt loop beneath the portion that drives the rollers. The belt can have advantages of being relatively quiet as compared to chains.

Another generally-known powered roller conveyor incorporates a drive chain that is topped by a drive pad that contacts the undersurface of the live rollers. This chain-driven pad is relatively narrow in horizontal cross section as installed down a longitudinal axis of the conveyor. Being narrow, the chain-driven pad can be horizontally turned at each end of a section of conveyor. This horizontal return loop enables curving the section of conveyor to the right or left as required rather than having to be essentially straight. Although providing design flexibility, the drive chain can create more noise than a belt implementation.

<CIT> discloses a conveyor section according to the preamble of claim <NUM>. Said document discloses a mechanical handling system having a conveyer consisting of a horizontal parallel array of rollers located over a drive belt that is essentially vertical and powered by a drive unit. The drive unit has two rollers whose axis of rotation are essentially upright and located either side of the belt. The rollers are transposed with respect to each other. The drive unit presses the drive belt against the transport roller.

<CIT> discloses an article conveyor having live rollers driven by a polymeric driven pad which has a wear indicator element co-extruded with the driven pad. The wear indicator element is visually distinct from the driven pad and has converging sides in the driven pad so that wear on the pad is indicated by the amount of the wear indicator element visible to an observer.

The accompanying drawings illustrate exemplary embodiments of the invention, and together with the general description given above and the detailed description given below, serve to explain the features of the invention, which is defined in claim <NUM>.

Embodiments of the invention become apparent from the dependent claims. A conveyor section for transportation or accumulation of articles such as cartons and totes includes a pair of spaced, opposing side rails, vertical frame members attached transversely between the pair of opposing side rails, and live rollers transversely attached for rotation between the opposing side. An upstream end idler and a downstream end idler both having a vertical axis of rotation are attached at respective upstream and downstream ends of the conveyor section. A drive belt is vertically elongate and supported for horizontal looping between the upstream and downstream end idlers. The drive belt supported and guided by the vertical frame members such that a drive loop side and a return loop side are horizontally positioned under the live rollers. The drive loop side of the drive belt is at selectively engageable to an undersurface of the live rollers. A drive motor is operatively coupled to drive the drive belt.

The various embodiments and arrangements will be described in detail with reference to the accompanying drawings.

<FIG> illustrates a powered roller conveyor <NUM> that is driven by a longitudinally positioned drive belt <NUM>. A bed <NUM> of transversely positioned live rollers <NUM> are axially attached to opposing side rails <NUM> of a conveyor section <NUM> to serve as a support surface for conveyed articles <NUM> such as totes or cartons. In one or more embodiments, the conveyor section <NUM> includes an infeed idler section <NUM>, a center drive section <NUM>, an intermediate section <NUM>, and a discharge idler section <NUM>. Articles <NUM> enter the infeed idler section <NUM> that has an end idler for supporting a proximal end of a horizontal loop of the drive belt <NUM>. The center drive section <NUM> includes a motor, drive pulley and belt tensioner <NUM> assembly. The intermediate section <NUM> can be the most common conveyor section with multiple intermediate sections <NUM> supported by the center drive section <NUM>. The articles <NUM> leave the conveyor section <NUM> at the discharge idler section <NUM>, which includes an end idler to support a distal loop of the drive belt <NUM>. A photo-eye guide rail <NUM> attached above each side rail <NUM> can provide information as to positions of the conveyed articles <NUM> such as for controlling zero- pressure accumulation before a merge into a sortation system. A wear indicator layer <NUM> of an enlarged head portion <NUM> or bulb contacts an underside of the live rollers <NUM>. The wear indicator layer <NUM> has a different color than the rest of the drive belt <NUM> so that excessive wear can be detected prior to any exceedance of service life.

<FIG> illustrates a curved conveyor section 110a of the powered roller conveyor <NUM> with a horizontally looped drive belt <NUM> following a curved path. Since the drive belt <NUM> as installed is relatively thin laterally with its strength provided by its vertical dimension, the drive belt <NUM> can be turned horizontally in a relatively small radius. An upstream end idler <NUM> and a downstream end idler <NUM> both having a vertical axis of rotation attached at respective upstream and downstream ends <NUM>, <NUM> of the conveyor section 110a. The drive belt <NUM> that is vertically elongate and is supported for horizontal looping between the upstream and downstream end idlers <NUM>, <NUM>, presenting drive side <NUM> and a return <NUM>.

<FIG> illustrate a straight conveyor section 110b of the powered roller conveyor <NUM> showing the drive side <NUM> and the return side <NUM> of the cutaway horizontally-looped drive belt <NUM>, supported within transverse frame members <NUM> attached between the side rails <NUM>. A drive loop side <NUM> and a return loop side <NUM> are horizontally positioned under the live rollers <NUM> with the return loop side <NUM> slight below and out of contact. Accumulator versions of the powered roller conveyor <NUM> can selectively engage portions of the drive loop side <NUM> while allowing other areas to coast to a stop. <FIG> illustrates the straight conveyor section 110b of the powered roller conveyor <NUM> having a transfer belt <NUM> installed over the live rollers <NUM>. The drive loop side <NUM> is in frictional engagement with the transfer belt <NUM>. The embodiments illustrated in <FIG> are not a part of the present invention.

<FIG> illustrate the horizontally-looped drive belt <NUM> having an enlarged drive head <NUM> for increased contact surface for driving a series of live rollers <NUM> (<FIG>). A wear indicator strip <NUM> formed in a top edge of the enlarged drive head <NUM> can provide an indication of a worn condition of the drive belt <NUM> prior to reaching its service life. <FIG> illustrates an elastomeric material <NUM> of the drive belt <NUM> for compressing on an inside of a turning radius and expanding on an outside of a turning radius. Vertically aligned center fibers <NUM> for strength are positioned between the compressing and expanding lateral sides of the drive belt <NUM>. The embodiments illustrated in <FIG> are not a part of the present invention.

<FIG> illustrate a horizontally-looped drive belt 102a in accordance with the invention having an enlarged drive head <NUM> for increased contact surface for driving a series of live rollers <NUM> (<FIG>) as well as a lower enlarged retention head <NUM>. In at least one embodiment, <FIG> illustrates an elastomeric material <NUM> of the drive belt 102a for compressing on an inside of a turning radius and expanding on an outside of a turning radius. Vertically aligned center fibers <NUM> for strength are positioned between the compressing and expanding lateral sides of the drive belt 102a. <FIG> illustrates a further alternative horizontally-looped drive belt 102b being vertically positioned for longitudinal movement by a pair of laterally opposing rollers <NUM> that have vertical axes of rotation, according to one or more embodiments. Instead of vertically stacked longitudinally projecting fibers, the drive belt 102b includes a bundle of fibers <NUM> in both the enlarged drive head <NUM> and a lower retention head <NUM>.

In one or more embodiments, the drive belt <NUM> can have a tensile pull capabilities of at least <NUM> ( <NUM> lbs ) and a minimum bend radius of at least <NUM> (<NUM> inches). The elastomeric material <NUM> can be a thermoplastic or polymeric material such as but not limited to a urethane, and can be an elastomer. An endless drive belt <NUM> made of thermoplastic urethane may be strong in tension and can be easily manufactured in long lengths. Fibers <NUM>, <NUM> can be formed from an aramid fiber, such as Kevlar™, but are not limited thereto. Additional materials for the Fibers <NUM>, <NUM> that serve as bendable tensile members can include, but are not limited to: steel, polyester, Nylon™, Nomex™, Vectran™, or any other suitable cord materials for belting. Fibers <NUM>, <NUM> can be separate fibers or fibers twisted together, and can be placed within drive belt <NUM> during the belt forming process. A coating can be applied to provide increase wear resistance and can comprise, but is not limited to, a layer of woven nylon fabric. Coating can be between about <NUM> - <NUM> ( <NUM> - <NUM> inches ) thick, such as about <NUM> ( <NUM> inches ) thick. In one or more embodiments, the elastomeric material <NUM> can be formed from thermoplastic urethane with a durometer of between about <NUM> and about <NUM> on the Shore A scale. For instance, elastomeric material <NUM> can have a durometer of about <NUM> on the Shore A Scale, but is not limited thereto. Durometer is a measure of "hardness" of an elastomeric material, and can be measured by a Shore A test instrument that applies an impact force to the urethane material, and measures the hardness of the urethane as an indentation depth resulting from that force. The <NUM> Shore A urethane material used in the drive belt <NUM> can be stiff, and can fall between a "hard" value of <NUM> Shore A described as a shoe heel, and an "extra hard" value of <NUM> Shore A described as a golf ball. This range information can be found at "http://www. casterland. com/info-durometer.

The embodiments illustrated in <FIG> are not a part of the present invention. <FIG> illustrate a conveyor system <NUM> that has a horizontally oriented V-backed drive belt <NUM> (<FIG>) that is vertically looped. <FIG> illustrates that the conveyor system <NUM> typically contains an infeed idler section <NUM>, a center drive section <NUM>, an intermediate section <NUM>, and a discharge idler section <NUM>. Each section <NUM>, <NUM>, <NUM>, <NUM> can include a transfer belt <NUM> over carrier (live) rollers <NUM> to enhance movement of small and light product such as polybags. Product (not shown) enters the conveyor system <NUM> on the infeed idler section <NUM> which contains one pressure shoe assembly <NUM> and an end idler pulley <NUM>. The V-backed drive belt <NUM> wraps around the end idler pulley <NUM>. The center drive section <NUM> is the first or second section after the infeed idler section <NUM> and can be pre-assembled to an intermediate section <NUM>. The center drive section <NUM> contains a motor, a drive pulley, and a pneumatic belt tensioner (not shown). Intermediate sections <NUM> are typically the most common conveyor section, making up long lengths of conveyor between the infeed and discharge end idler sections <NUM>, <NUM>. Product entering the conveyor system <NUM> should already be aligned to one edge. Typically, this alignment is created by hard-skewed rollers in an upstream V-belt conveyor (not shown). Product leaves the conveyor system <NUM> from the discharge idler section <NUM>. The discharge idler section <NUM> contains two pressure shoe assemblies <NUM> and the end idler pulley <NUM>. The discharge idler section <NUM> is supplied with a separate solenoid-controlled valve (not shown) that controls the release of the discharge idler section <NUM>.

<FIG> illustrates that the intermediate sections <NUM> include frames <NUM>, carrier (live) rollers <NUM>, a zone control ZoneFlex module <NUM>, and necessary components to support the drive belt <NUM> and general operation. Three-foot-long zones <NUM>, <NUM> can be used for controlling the product flow. Each zone <NUM>, <NUM> has a photo-eye <NUM>, reflector <NUM>, air diaphragms <NUM>, and shares a ZoneFlex Module <NUM>. A light beam travels across the intermediate section <NUM> from the photo-eye <NUM> to the reflector <NUM> and back to the photo-eye <NUM>. When product blocks the light beam, the photo-eye <NUM> sends a signal to the ZoneFlex Module <NUM>, which inflates or deflates the air diaphragm <NUM>. When the air diaphragms <NUM> are inflated, the air diaphragms <NUM> mounted on a pressure shoe support <NUM> raise the pressure shoe assembly <NUM> including pressure rollers <NUM> that frictionally engage the V-backed drive belt <NUM> up against the bottom of the transfer belt <NUM>. Thereby, the transfer belt <NUM> for that zone <NUM>, <NUM> discontinues coasting and is longitudinally moved at the speed of the drive belt <NUM>. Some upstream live rollers <NUM> are connected by power transfer bands <NUM> to move with downstream roller that makes effective frictional engagement to the drive belt <NUM>. <FIG> illustrates the offset contact between V-backed drive belt <NUM> and the transfer belt <NUM>.

The driving contact between the drive belt <NUM> and the transfer belt <NUM> is off center and a prototype testing configuration did not include mechanisms to maintain tracking of the transfer belt <NUM>. However, extended testing has shown that the transfer belt <NUM> wears in a uniform manner and maintains tracking. <FIG> illustrates a graphical plot <NUM> of test results for tracking location of a transfer belt installed on a INTELLIQ accumulation conveyor. <FIG> illustrates a graphical plot <NUM> of test results for deviation of the transfer belt installed on the INTELLIQ accumulation conveyor. <FIG> illustrates a graphical plot <NUM> for tracking location.

Testing on two belts was performed to determine whether a transfer belt could be driven by a side mounted narrow drive belt without tracking or uneven wear problem. In particular, the selected transfer belt tested was POLYSPRINT TC PS-<NUM> available from NITTA CORPORATION:.

The specific design and testing parameters for the tested transfer belt were as follows:.

Installation parameters were determined as follows:
Effective Tension Te <NUM> N, Formulation Te = (WG + WB + WC)/<NUM> + WG sin θ + (MG + MB) × α; Tensionx2 2To <NUM> N, Formulation <NUM>To = Te × (K + C<NUM>) × C2.

Test setup was designed to test a worst case scenario:.

Claim 1:
A conveyor section comprising:
a pair of spaced, opposing side rails (<NUM>);
live rollers (<NUM>) transversely attached for rotation between the opposing side rails (<NUM>) providing a conveying surface for articles (<NUM>);
an upstream end idler (<NUM>) and a downstream end idler (<NUM>) both having a vertical axis of rotation attached at respective upstream and downstream ends (<NUM>, <NUM>) of the conveyor section;
a drive belt (102a) that is vertically elongate and having a drive loop side and a return loop side that are horizontally positioned under the live rollers with the drive loop side engageable to an undersurface of the live rollers, wherein the drive belt (102a) is supported for horizontal looping between the upstream and downstream end idlers (<NUM>, <NUM>);
a drive motor operatively coupled to drive the drive belt (102a); wherein the drive belt (102a) comprises an upper enlarged head portion (<NUM>) for increased contact surface for driving a series of live rollers, characterised in that the conveyor section comprises vertical frame members (<NUM>) attached transversely between the pair of opposing side rails (<NUM>), wherein the drive belt (102a) is supported by the vertical frame members (<NUM>), and wherein the drive belt (102a) comprises a lower enlarged retaining portion (<NUM>).