Conveyor chain

A section of chain for conveying product along a material handling system includes a pin connecting a center link between two side links. The pin may be dialable or selectably positioned at the side links to control and adjust the wear surface of the pin relative to the chain links. The pin may have a rotationally non-symmetrical shaft portion to provide different wear surfaces that engage a center link of the section of chain. The different wear surfaces may be sized and shaped to accommodate wear at the wear surface of the center link. The shaft portion may include a rotationally non-symmetrical ball member or portion on the shaft portion to enhance flexibility of the section of chain. The pin may be dialed to the next position or wear surface in response to an output of a wear measurement device or system.

FIELD OF THE INVENTION

The present invention relates generally to chains for a conveying system and, more particularly, to bolted or pinned chains which allow for pivotable movement between a center link and a pair of side links about an axis defined by a bolt or pin extending therethrough.

BACKGROUND OF THE INVENTION

Chains for power transmission or for material handling and processing systems, such as, for example, chains which function to move a plurality of trolleys or the like along a path in a processing plant, warehouse or the like, flex as the chain travels along the desired path. As the chain is routed along the desired path, the chain may flex to make lateral turns and/or upward or downward curves along the path. As the chain flexes, the links of the chain may move relative to the pins or bolts which define the joints of the chain. The relative movement of the links and the pins or bolts leads to wear on the components and may eventually lead to a failure of the links and/or the pins or bolts. The wear may increase if the friction between the pin and the links increases, such as due to a roughened surface (such as by machining grooves, scratches or the like) of one or more of the components and/or a lack of lubrication on the components.

In certain situations, the chains may have to negotiate an incline from horizontal which is approximately 45–60 degrees above or below horizontal. Such sharp inclines may result in binding of the chain links as they flex or bend along the curve. It is known to provide an I-pin chain with a ball formed on the forged I-pin between the side links and the center link of the chain. The I-pin may be forged with a ball or spherical shape at a center portion of the pin, such that the center link may be pivotable about the ball between the side links. The I-pin is fixed relative to the side link and center link of the chain, which is commonly known as “rivetless chain.” The ball may provide for additional flexibility in the chain, but still wears against the center chain links as the chain links move relative to the pins.

Therefore, there is a need in the art for an improved chain that overcomes the short comings of the prior art.

SUMMARY OF THE INVENTION

The present invention is intended to provide enhanced flexibility of chain links and enhanced relative movement between the chain links and pins, while reducing or controlling wear on the chain or reducing or controlling the effects of wear on the chain components.

According to another aspect of the present invention, a pin for connecting chain links together to define a section of chain for conveying product along a conveying system comprises opposite end portions for engaging at least one link of the section of chain, a shaft portion extending between the opposite end portions, and a sleeve portion around and at least partially along the shaft portion. The sleeve portion is arranged on the shaft portion to engage another link of the section of chain when the opposite end portions are engaged with the at least one link of the section of chain. The sleeve portion is movable relative to the shaft portion.

In one form, the sleeve portion comprises a generally spherical or toroidal-shaped member, which may be generally centrally positioned along the shaft portion. The sleeve portion may include a spacer portion at one or both ends of the toroidal-shaped member. The shaft portion of the pin may be generally cylindrical or may have a spherical or ball or rounded portion formed thereon. In another form, the shaft portion may comprise a generally cylindrical shaft portion and the sleeve portion may comprise a generally cylindrical sleeve portion.

The sleeve portion may comprise a polymeric material. The sleeve portion may be molded onto the shaft portion of the pin, which may be an I-pin or bolted pin or the like, or the sleeve portion may be slid or removably positioned over the shaft portion of a bolted pin or stud type pin when a fastener is removed from a fastener end of the pin.

Optionally, the sleeve portion may comprise a low coefficient of friction coating on an inner surface of the sleeve portion which slidably engages the shaft portion, or the sleeve portion may comprise a low coefficient of friction coating on an outer surface of the sleeve portion which engages the other chain link.

According to another aspect of the present invention, a section of chain for conveying product along a conveying system comprises a first chain link, at least one second chain link having apertures through opposite ends thereof, and a pin. The second chain link comprises a recessed area surrounding at least a portion of the aperture. The pin connects the first chain link to the second chain link via insertion of the pin through a respective one of the apertures in the second chain link and through an opening in the first chain link. The pin has at least one head portion and a shaft portion, with the head portion defining a mating surface. The recessed area rotatably receives the mating surface of the head portion of the pin. The mating surface is correspondingly formed with the recessed area to facilitate relative rotation therebetween. The mating surface engages the recessed area of the second chain link and is rotatable relative to the second chain link as the section of chain conveys product along the conveying system.

The aperture may comprise a slotted opening having a narrowed region adjacent to the recessed area and a larger diameter region adjacent to the narrowed region. The head portion of the pin is insertable through the larger diameter region and the shaft portion is slidable through the narrowed region to the recessed area, whereby the mating surface of the head portion engages the recessed area to retain the pin in the aperture.

According to another aspect of the present invention, a section of chain for conveying product along a conveying system comprises at least two chain links having apertures through opposite ends thereof and a pin connecting the chain links together via insertion of the pin through the apertures in the chain links. The pin comprises opposite end portions and a shaft portion extending between the opposite end portions. The shaft portion defines a wear surface which engages at least one of the chain links. The pin is selectably adjustable between at least three positions relative to the chain links to adjust the wear surface of the shaft portion relative to the chain links. The pin is generally non-rotatable relative to the chain links when in each of the at least three positions.

At least one of the end portions of the pin may define at least three engaging portions for selectably engaging corresponding wall portions of the aperture of at least one of the chain links, whereby the pin is generally non-rotatable relative to the chain links by engagement of at least some of the engaging portions with at least some of the wall portions when in each of the at least three positions.

According to another aspect of the present invention, a method of adjusting a wear surface of a pin of a section of chain comprises providing a section of chain having at least two chain links having apertures through opposite ends thereof and a pin connecting the chain links together via insertion of the pin through the apertures in the chain links. The pin comprises opposite end portions and a shaft portion extending between the opposite end portions. The shaft portion defines a wear surface which engages at least one of the chain links. The pin is non-rotatably positioned relative to the chain links in one of at least two positions. The pin is generally non-rotatable relative to the chain links when in each of the at least two positions. The pin is selectably rotated to a different one of the at least two positions relative to the chain links to adjust the wear surface of the shaft portion relative to the chain links.

A degree of wear on the pin may be monitored and the pin may be selectably rotated to limit or control wear on wear surfaces of the pin corresponding to the at least two positions. The method may include monitoring a degree of wear on a portion of the engaged wear surface of the pin and selectively rotating the pin to position a new wear surface at the chain link in response to the degree of wear. For example, the method may include determining a degree of wear of the section of chain via a wear measurement device, and may further include selectively rotating the pin in response to an output of the wear measurement device. The pin may be marked to indicate which of the at least two positions have been selected and used.

According to another aspect of the present invention, a pin adapted for connecting at least two chain links of a section of chain includes a shaft portion and at least one head portion at at least one end of said shaft portion. The shaft portion is configured to engage at least one of the chain links. The shaft portion comprises a rotationally non-symmetrical shaft portion and has at least two wear surfaces for engaging the chain link. The at least one head portion defines at least two portions for selective engagement with a corresponding portion of the other of the chain links.

The shaft portion of the pin may include a ball member positioned thereon. The ball member may be rotationally non-symmetrical and may define the wear surfaces. The ball member may be integrally formed with the shaft portion or may receive the shaft portion therethrough, and may be removably positioned on the shaft portion.

According to yet another aspect of the present invention, a section of chain for conveying product along a conveying system comprises at least two chain links and a pin for connecting the chain links together. At least one of the chain links defines a pin engaging region. The pin engaging region defines a first wear surface. The pin has opposite end portions and a shaft portion and defines a second wear surface. At least one of the first and second wear surfaces comprises a polymeric material.

At least one of the pin engaging regions and the pin has a low coefficient of friction coating thereon. The coating may comprise a diamond like coating at at least one of the first and second wear surfaces.

According to another aspect of the present invention, a section of chain for conveying product along a conveying system comprises at least two chain links and a pin for connecting the chain links together. At least one of the chain links defines a pin engaging region. The pin engaging region defines a first wear surface. The pin has opposite end portions and a shaft portion and defines a second wear surface. At least one of the first and second wear surfaces comprises a replaceable wear surface, whereby the replaceable wear surface is removable from the at least one chain link and/or removable from the pin to facilitate replacement of the replaceable wear surface.

The replaceable wear surface may comprise a polymeric material. The replaceable wear surface may comprise a sleeve positionable around the shaft portion of the pin. The sleeve may comprise a toroidal-shaped member. The replaceable wear surface may comprise an insert at an end portion of the at least one chain link, whereby the insert engages the shaft portion of the pin. The pin engaging regions and/or the pin may have a low coefficient of friction coating thereon, such as a TEFLON® coating or a diamond like coating or the like, at the first and/or second wear surfaces.

According to another aspect of the present invention, a pin for connecting and retaining at least two chain links of a section of chain comprises a shaft portion and a replaceable wear surface member removably positioned around at least a portion of the shaft portion. The section of chain is movable to convey product along a conveying system. The replaceable wear surface is removable from the pin to facilitate replacement of the replaceable wear surface.

The pin may comprise at least one fastening portion at at least one end of the pin for receiving a fastener thereon to retain the pin at the chain links. The replaceable wear surface may be removable and replaceable via sliding the replaceable wear surface off from and onto the shaft portion at the fastening portion when the fastener is removed therefrom. The replaceable wear surface may comprise a toroidal-shaped member or a generally cylindrical member or the like. The replaceable wear surface may comprise a metallic or a polymeric material and may be coated with a low coefficient of friction material or coating.

According to yet another aspect of the present invention, an I-pin for a chain includes opposite head portions and a shaft portion. A unitary polymeric sleeve is movably positioned around at least a portion of the shaft portion of the I-pin. The polymeric sleeve may rotate or slide around the shaft portion.

The sleeve may be molded onto the shaft portion and may be broken free after it has been molded and, thus, may be generally freely rotatable about the shaft portion of the I-pin. The sleeve provides a unitary polymeric component on the shaft portion of the I-pin for engagement with the center link and/or side links of a chain. The sleeve may be molded of a durable polymeric material.

Optionally, the shaft portion of the I-pin may have a smooth exterior surface to facilitate loosening or breaking free of the sleeve about the shaft portion. A low coefficient of friction surface or material may be provided between the sleeve and the pin and/or between the sleeve and the chain links.

In one form, the polymeric sleeve may be molded in a generally spherical shape to provide a generally spherical or toroidal-shaped ball member on the shaft portion of the pin. In another form, the shaft portion of the pin may include a ball member, such that the sleeve is molded over the ball member of the pin. In another form, the sleeve may be a generally cylindrical sleeve molded over a generally cylindrical shaft portion of the pin.

According to another aspect of the present invention, a method for forming an I-pin includes forming a pin having a shaft portion and molding a polymeric sleeve portion onto the shaft portion of the I-pin. The sleeve portion may be a generally cylindrical sleeve portion or may be a generally spherically shaped ball member molded onto the shaft portion of the pin. The sleeve portion may be broken free from the shaft portion of the pin such that the sleeve portion is movably or slidably positioned on the shaft portion.

Therefore, the present invention provides a pin member or pin which may provide enhanced flexibility and wear life to a section of chain. The pin may have a movable sleeve portion around a shaft portion of the pin to reduce friction and wear on the pin and on the chain links of the section of chain. The pin may include a ball member or toroidal-shaped member at or on the shaft portion of the pin, and the center link may include a concave engaging surface for engaging the ball member, to enhance flexibility of the section of chain. The present invention may provide a rotatable pin for rotating within the chain links as the chain travels and bends along the conveying path. Optionally, the chain may be selectably rotated or dialed between two or more generally fixed orientations relative to the chain links to control the wear on the pin and enhance the life cycle of the pin. Optionally, the pin or one or more of the chain links may have a wear surface which comprises a polymeric material, which may reduce friction between the pin and chain links. The polymeric wear surface may be a polymeric insert at an end of the center link or may be a polymeric sleeve portion molded or positioned around the shaft portion of the pin. The pin may comprise an I-pin type of chain pin, a bolted type of chain pin or a double ended stud type of chain pin, and may include a generally spherical-shaped ball member or toroidal-shaped member at the shaft portion to enhance flexibility in the section of chain. Optionally, the pin and/or the chain link may have a replaceable wear surface member to facilitate replacement of the wear surface or surfaces, without having to replace the entire pin and/or chain link.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and the illustrative embodiments depicted therein, a chain or section of chain10for conveying product along a conveying system, such as for material handling or processing systems or the like, includes a pair of side links12a,12band a center link14(FIGS. 1–3). The center link14is retained between the side links12a,12bby a double ended stud or stud type pin16, which extends through a center region14aof center link14and through an opening13in each side link12a,12band is retained therein by a corresponding fastener or nut18. Stud16includes a generally spherical or toroidal-shaped ball member20positioned generally at a mid-point or mid-region of a shaft portion16aof stud16. Chain10includes multiple linkages connected together in a continuous loop about a conveying system, as is known in the art. For ease of description, only one section or set of linkages of the chain is shown and described herein, with the other linkages of the chain being substantially identical.

Stud16includes center or shaft portion16aand a pair of opposite threaded portions or fastener portions or ends16b. Threaded portions16bare of a narrower diameter than shaft portion16a, such that the ends of center portion16aprovide an abutting surface16cagainst the fastener18as the fastener is tightened onto stud16or for abutting against an inward side of the respective side link12a,12b, to maintain the spacing between the side links when the chain is assembled. Stud16may comprise a metallic material, such as steel, stainless steel or iron or the like, similar to conventional studs or pins of chain for material handling systems and the like.

Ball member20may be integrally formed as part of stud16or may be press-fit or otherwise secured on shaft portion16ato retain the position of ball member20in the middle region of stud16. However, ball member20may otherwise be loosely fit onto shaft portion16aof stud16and allowed to slide along or rotate around stud16, without affecting the scope of the present invention. Ball member20may comprise a metallic material or a plastic or polymeric material. Center link14is a generally oval shaped or elongated ring and includes an inner rounded or concave mating or engaging surface14b(FIGS. 2 and 3) at each end thereof for engaging and partially receiving ball member20therein to retain center link14at ball member20as the chain is moved along the conveying path.

Ball member20thus allows for pivotal movement of center link14via sliding engagement of concave surface14balong ball member20. This provides greater flexibility to bolted chain10and may allow bolted chain10to negotiate sharper vertical curves in the conveying path without binding the links or joints of the chain. The ball member and correspondingly formed concave surface thus may distribute the loads over a generally constant surface area, reducing or substantially eliminating the stress concentration that typically occur when conventional chains articulate through vertical inclines and declines. The ball member and concave surface engagement may also function to distribute the loads between the chain links and stud or pin over a greater surface area than conventional chains. This decreases the wear on the bolt and chain links and may result in less maintenance and a greater life cycle for the chain.

Referring now toFIGS. 4–6, a chain or section of chain110includes a pair of side links112a,112band a center link114. The center link114is retained between corresponding ends of the side links112a,112bby a bolt or bolted pin116extending through corresponding openings113and through a center region114aof center link114. Bolt116includes a shaft portion116a, a threaded portion or end116b, which threadedly receives a nut118thereon to retain the chain links together, and a head or head portion116cat an opposite end from threaded end116b. Bolt116further includes a generally spherical or generally toroidal-shaped ball member120, which may slide onto shaft portion116aof bolt116. Similar to center link14, center link114is a generally elongated ring with a rounded or concave surface114bat each end thereof for engaging and partially receiving ball member120therein to maintain center link114on ball member120.

Ball member120may be loosely fit along bolt116to ease assembly of the chain links and to allow the ball member120, and thus the center link114, to move between the side links as the chain links negotiate through the conveying path. Optionally, ball member120may snugly receive shaft portion116aor may be press fit onto shaft portion116ato retain ball member120in place on shaft member116aof bolt116. Because ball member120defines a wear surface of bolt116, ball member120may be removably positioned on shaft portion116ato allow the ball member and wear surface to be replaced without replacing the entire bolted pin, thereby reducing maintenance and replacement costs of the chain components.

Optionally, as shown inFIGS. 7 and 8, a chain or section of chain110′ includes side links112a,112band a center link114. The center link114is retained between corresponding ends of the side links112a,112bby a bolt or bolted pin116′ extending through corresponding openings113and through center region114aof center link114. Bolt116′ includes a shaft portion116a′, a threaded portion or end116b′, which threadedly receives a nut118′ thereon to retain the chain links together, and a head or head portion116c′ at an opposite end from threaded end116b′. Bolt116′ further includes a sleeve portion or a spacer-ball-spacer assembly or member or portion119(FIG. 8), which may include a generally spherical or toroidal-shaped ball member or portion120′ and generally cylindrical spacers or sleeves121positioned at opposite ends of the ball member120′. As discussed above, center link114may be a generally elongated ring with a rounded or concave surface114bat each end thereof for partially receiving ball member120′ therein to maintain center link114on ball member120′.

Sleeve portion119may slide onto shaft portion116a′ of bolt116′ or may be molded thereon. Sleeve portion119may comprise a metallic material, such as steel or the like, and may be treated or coated, such as with a low coefficient of friction material or slick material, such as a TEFLON® coating or material or a diamond like coating (DLC) or other suitable low friction material or the like, such that sleeve portion119provides a highly durable and slick wear surface or engaging surface along shaft portion116aof bolt or pin116. Optionally, sleeve portion119may comprise a polymeric material and may be slid onto or molded onto shaft portion116a, which may comprise a metallic material.

Sleeve portion119may be loosely fit along bolt116′ to ease the assembly of the chain and to allow the ball member120′ and spacers or sleeves121, and thus the center link114, to move between the side links as the chain links negotiate through the conveying path. Sleeve portion119may include a hollow spacer ring or sleeve121positioned around and along the shaft116a′ at one or both sides of ball member120′ to maintain ball member120′ generally at a center region of the shaft116a′ of pin116′. The spacer-ball-spacer configuration or assembly may be formed as a unitary member (as shown inFIG. 8) or may be separate components (one or two spacers and a ball member) slid onto the shaft portion116a′, without affecting the scope of the present invention. By making the spacer-ball-spacer configuration a unitary structure, assembly of the bolt and maintenance or replacement of the wear surface/ball member (if necessary) may be substantially simplified.

Such a spacer-ball-spacer configuration assists in maintaining the ball member in the center region of the shaft of the pin, while allowing for generally free rotational movement of the ball member about the shaft. This helps to keep the ball member in alignment with the recess114bin center link114as the chain bends and moves along its conveying path. The spacer-ball-spacer configuration also provides for low cost replacement of the wear portions of the pin, since the spacer-ball-spacer assembly may be replaced without replacing the entire pin. For example, the nut may be removed and the spacer-ball-spacer structure (preferably a unitary structure) may be slid off of the bolt and replaced, thereby providing a new wear surface (a new ball member) to the bolted pin, without replacing the entire bolted pin. This may provide significant cost savings, especially in applications where the pin may be formed of stainless steel or other expensive materials and, thus, may be costly to replace.

Referring now toFIGS. 9 and 10, a chain or section of chain210includes a pair of side links215,212and a center link214. The center link214is retained between the side links215,212by a threaded or bolted pin216which extends through a center region214aof center link214and through an opening215ain side link215and an opening213in side link212and is retained therein and therethrough by a corresponding fastener or nut218. Threaded pin216includes a generally spherical or toroidal-shaped ball member220positioned generally at a mid-point or mid-region of threaded pin216. Similar to chain10, chain210includes multiple linkages connected together in a continuous loop about a conveying system, as is known in the art. For ease of description, only one set of linkages of the chain is shown and described herein, with the other linkages being substantially identical.

Threaded pin216includes a center portion or shaft portion216aand a threaded portion216bat one end of the shaft portion216aand a head or head portion216cat the other end of the shaft216a. Threaded portion216bhas a narrower diameter than center portion or shaft216a, such that the end of shaft216aprovides an abutting surface216dfor abutting against the fastener or nut218as the nut is tightened onto threaded pin216or for abutting against an inward side of side link212, to maintain the spacing between the side links when the chain is assembled.

As can be seen inFIGS. 9 and 10, head216cof threaded pin216is a generally rectangular shaped head such that portions of the head216cextend laterally outward from the end of the shaft216ain opposite directions. Side link215includes a pair of slotted openings215awhich may be sized to receive head216ctherethrough when the head is rotated approximately 90 degrees from the orientation shown inFIG. 9, in order to facilitate assembly and disassembly of the chain links. Alternately, side link215may include circular apertures or passageways similar to side link212, because the threaded portion216band shaft216amay be inserted through such an aperture or opening to assemble the section of chain. Side link215includes a recessed region or pocket215bat each end for head216cof threaded pin216to rest when the section of chain is assembled. The recessed region215bis defined by a raised end portion215cand raised inward portions215dwhich engage the sides of the head216cto substantially preclude rotation of the pin relative to the side and center links.

Center link214may be substantially similar to center links14and114, discussed above, and may comprise a generally oval shaped or elongated ring defining an opening214aand having an inner rounded or concave surface214bat each end of the center link for partially receiving ball member220therein to retain center link214at ball member220as the chain is moved along the conveying path.

Ball member220may be slid loosely onto shaft216aof threaded pin216and allowed to slide and rotate along shaft216a, or may be press fit onto or substantially fixed relative to shaft216a, without affecting the scope of the present invention. Alternately, the threaded pin and ball member may be forged or otherwise integrally formed as a single member, without affecting the scope of the present invention.

Similar to ball members20and120of chains10and110, respectively, ball member220of chain210allows for pivotal movement of center link214via sliding engagement of concave surface214balong ball member220. This provides greater flexibility to chain210and may allow the chain to negotiate sharper vertical curves in the conveying path without binding the links or joints of the chain. Chain210thus provides a half rivetless-half bolted pin which may negotiate sharper vertical turns and/or negotiate turns about different axes. The ball member and correspondingly formed concave surface thus may distribute the loads over a generally constant surface area, reducing or substantially eliminating the stress concentration that typically occur when conventional bolted chains articulate through vertical inclines and declines. The ball member and concave surface engagement may also function to distribute the loads between the chain links and bolt over a greater surface area than conventional bolted chains. This decreases the wear on the bolt and chain links and may result in less maintenance and a greater life cycle for the chain.

Although shown as having a generally rectangular shaped head, the threaded pin of the present invention may alternately have a rounded head (not shown inFIGS. 9 and 10) which may rest upon a generally flat or recessed side link, thereby allowing the threaded pin to rotate relative to the side and center links, without affecting the scope of the present invention.

Referring now toFIGS. 11–13, a chain or section of chain310includes a pair of side links315,312and a center link314. The center link314is retained between the side links315,312by a threaded pin or bolted pin316which extends through a center region314aof center link314and through an opening315ain side link315and an opening313in side link312and is retained therein and therethrough by a corresponding fastener or nut318. Threaded pin316includes a generally spherical or toroidal-shaped ball member320positioned generally at a mid-point or mid-region of a shaft portion316aof threaded pin316. Similar to chain10, chain310includes multiple linkages connected together in a continuous loop about a conveying system, as is known in the art. For ease of description, only one section or set of linkages of the chain is shown and described herein, with the other sections or sets of linkages being substantially identical.

Threaded pin316includes center portion or shaft portion316a, a threaded portion or end316bat one end of the shaft portion316a, and a head portion316cat the other end of the shaft portion316a. Threaded portion316bhas a narrower diameter than shaft portion316a, such that the end of shaft portion316aprovides an abutting surface316dfor abutting against the fastener or nut318as the fastener is tightened onto threaded pin316or for abutting against an inward side of side link312, to maintain the spacing between the side links when the chain is assembled. Head portion316cmay include a hex head or the like to facilitate preventing rotation of the bolt while the fastener318is being fastened thereto.

As can be seen inFIGS. 11–13, head316cof threaded pin316is a generally circular-shaped head. Side link315includes a pair of slotted openings315awhich include a larger inward opening315b, which may be sized to receive head316ctherethrough, in order to facilitate assembly and disassembly of the chain links, and a smaller outward opening315c, which is smaller than the diameter of head316cto retain head316ctherein. The smaller opening315cdefines a narrowed slotted region adjacent to larger opening315b, to allow shaft portion316ato slide along the slotted region to position head portion316cat smaller outward opening315c, whereby head portion316cis retained in the smaller opening315c, as discussed below. Alternately, side link315may include circular apertures or passageways similar to side link312, because the threaded portion316band shaft portion316amay be inserted through such an aperture or opening to assemble the section of chain.

Side link315includes a recessed area or region or pocket315dat and at least partially around the smaller opening315cat each end for head portion316cof threaded pin316to rest when the chain is assembled. The lower portion or mating surface316d(FIG. 13) of head portion316cis preferably curved or rounded, while the recessed region315dis correspondingly formed to provide generally uniform engagement and mating between the mating surface316dof head portion316cand recessed region315d. The correspondingly formed mating surface and recessed region facilitate substantially smooth rotation between the pin316and the link315, such that the bolted pin316may freely rotate relative to side links315,312and center link314as the chain travels along its conveying path.

Center link314may be substantially similar to the center links discussed above, and may comprise a generally oval shaped or elongated ring defining an opening314aand having an inner rounded or concave surface314bat each end thereof for partially receiving ball member320therein to retain center link314at ball member320as the chain is moved along the conveying path.

Similar to the ball members and chains discussed above, ball member320of chain310allows for pivotal movement of center link314via sliding engagement of concave surface314balong ball member320. This provides greater flexibility to chain310and may allow the chain to negotiate sharper vertical curves in the conveying path without binding the links or joints of the chain. Chain310thus provides a half rivetless-half bolted pin which may negotiate sharper vertical turns and/or negotiate turns about different axes. The ball member and correspondingly formed concave surface thus may distribute the loads over a generally constant surface area, reducing or substantially eliminating the stress concentration that typically occur when conventional bolted chains articulate through vertical inclines and declines. The ball member and concave surface engagement may also function to distribute the loads between the chain links and bolt over a greater surface area than conventional bolted chains. This decreases the wear on the bolt and chain links and may result in less maintenance and a greater life cycle for the chain.

Ball member320may be slid loosely onto shaft portion316aof threaded pin316and allowed to slide and rotate along shaft portion316a, or may be press fit onto or substantially fixed relative to shaft portion316a, without affecting the scope of the present invention. Alternately, the threaded pin and ball member may be forged or otherwise integrally formed as a single member, without affecting the scope of the present invention. Optionally, ball member320may be loosely slid onto shaft portion316a, and may include a hollow spacer ring or sleeve (such as shown generally at321inFIG. 13) positioned along and around the shaft portion316aat one or both sides of ball member320to maintain ball member320generally at a center region of shaft portion316aof pin316. The spacer-ball-spacer configuration or assembly may be formed as a unitary member or may be separate components (two spacers and a ball member) slid onto the shaft portion316a, without affecting the scope of the present invention. By making the spacer-ball-spacer configuration a unitary structure, assembly of the bolt and maintenance or replacement of the ball member (if necessary) may be substantially simplified.

As discussed above with respect to bolted pin116′, such a spacer-ball-spacer configuration assists in maintaining the ball member in the center region of the shaft of the pin, while allowing for generally free rotational movement of the ball member about the shaft. This helps to keep the ball member in alignment with the recess314bin center link314as the chain bends and moves along its conveying path. The spacer-ball-spacer configuration also provides for low cost replacement of the wear portions of the pin, since the spacer-ball-spacer assembly may be replaced without replacing the entire pin. The nut may be removed and the spacer-ball-spacer structure (preferably a unitary structure) may be slid off of the bolt and replaced, thereby providing a new wear surface (a new ball member) to the bolted pin, without replacing the entire bolted pin. This may provide significant cost savings, especially in applications where the pin may be formed of stainless steel or other expensive materials and, thus, may be costly to replace.

Referring toFIGS. 14 and 15, a chain or section of chain310′ includes a pair of side links315,312and a center link314′. The center link314′ is retained between the side links315,312by a threaded pin316′ which extends through a center region314a′ of center link314′ and through an opening315ain side link315and an opening313in side link312and is retained therein and therethrough by a corresponding fastener or nut318. Threaded pin316′ includes a generally cylindrical shaft portion316a′, while center link314′ includes a generally flat or curved, non-concave surface314b′ for engaging shaft portion316a′. Chain310′ may be otherwise substantially similar to chain310, discussed above, such that a detailed discussion will not be repeated herein. Head portion316c′ may include a curved or rounded mating surface316d′, while side link315may include a correspondingly formed mating surface315dat the smaller slotted opening315c, as discussed above, to facilitate generally smooth rotation of pin316′ relative to the chain links. Optionally, threaded pin316′ may include a generally cylindrical sleeve portion (not shown inFIGS. 14 and 15) formed or positioned around shaft portion316a′, such as discussed above or as discussed below.

Optionally, and as shown inFIG. 15A, a chain or section of chain310″ includes a pair of side links312a,312band a center link314′. The center link314′ is retained between the side links312a,312bby a threaded pin316″ which extends through center link314′ and through an opening313ain side link312aand an opening313bin side link312band is retained therein and therethrough by a corresponding fastener or nut318′. The head portion316c″ may include a curved or rounded mating surface316d″ for engaging a correspondingly formed mating surface313cof side link312a, while the nut or female fastener318′ may include a similarly curved or rounded or chamfered mating surface318a′ for engaging a correspondingly formed mating surface313dof side link312bto facilitate generally smooth rotation of pin316″ relative to the chain links. The engaging or mating surfaces316d″ and318a′ of the head and nut may be generally correspondingly formed to match the recesses in the side links, such that the side links may be generally interchangeable without adversely affecting the rotation of the pin relative to the side links. The chamfers or curved mating surfaces may be at the ends of otherwise conventional hex heads and nuts, or may comprise generally curved circular base portions (such as shown at the head of the pins inFIGS. 11–15) of the heads and nuts to enhance rotation of the pin and reduce wear on the side links.

In the illustrated embodiment, threaded pin316″ includes a generally cylindrical shaft portion316a″, while center link314′ includes a generally flat, non-concave surface314b′ for engaging shaft portion316a″. However, the shaft portion may be otherwise formed, and may include a ball member or the like formed or positioned thereon, such as described herein. In applications with such a ball member, the side link312amay be replaced with a side link similar to side link315ofFIGS. 11–15to ease assembly of the section of chain. Optionally, the threaded pin316″ may include a generally cylindrical sleeve portion (not shown inFIG. 15A) formed or positioned around shaft portion316a″, such as also discussed herein. Chain310′ may be otherwise substantially similar to chain310, discussed above, such that a detailed discussion will not be repeated herein.

Additionally, it is further envisioned that a round headed pin may be provided with a rounded head at each end of the pin and a ball member on the shaft portion between the heads or head portions. The head portions may insert through enlarged, generally circular openings in the side links and slide outwardly toward the ends of the side links to a narrowed opening. The narrowed opening substantially precludes the circular heads from moving therethrough, and thus retains the side links relative to the center links and the pin. The side links may include a recessed area around the narrowed opening to receive the rounded head therein to substantially preclude longitudinal movement of the pin relative to the side link toward the enlarged opening in the side link. The pin is thus allowed to rotate relative to the side links and the center link, while allowing greater flexibility and reduced wear of the chain.

For example, and with reference toFIGS. 16–18, a chain or section of chain410includes a pair of side links412a,412band a center link414. The center link414is retained between the side links412a,412bby a pin416which extends through a center region414aof center link414and through an opening413in each side link412a,412b. Openings413include a larger, inward generally circular opening413aand a smaller, outer generally circular slot or opening413b. Each head portion416cof pin416is smaller than the larger opening413aand larger than the smaller end opening413bin each side link412a,412band retains pin416to side links412a,412band center link414. Pin416includes a generally spherical or toroidal-shaped ball member420positioned generally at a mid-point or mid-region of a shaft portion416bof pin416. Center link414may be substantially similar to the center links discussed above and may comprise a generally oval-shaped or elongated ring having an inner rounded or concave surface414bat each end thereof for partially receiving ball member420therein to retain center link414at ball member420as the chain is moved along the conveying path. Similar to chain10, chain410includes multiple linkages connected together in a continuous loop about a conveying system, as is known in the art. For ease of description, only one section or set of linkages of the chain is shown and described herein, with the other sections or sets of linkages being substantially identical.

Pin416includes center portion or shaft portion416aand a head portion416cat each end of the shaft portion416a. Head portions416care generally circular and include an angled or curved underside portion or mating surface416d(FIG. 18) which extends generally radially outward from each end of the shaft portion416asuch that head portion416chas a larger diameter than shaft portion416a.

As can be seen inFIGS. 16 and 17, each side link412a,412bincludes a pair of slotted openings413which may be sized to receive head416cthrough the larger inward opening413a, in order to facilitate assembly and disassembly of the chain. Once inserted through openings413a, pin416and head portion416cmay be moved outwardly until shaft portion416ais within outer slot or opening413b. Head portion416cthen may rest at least partially within a curved recessed portion413cat outer opening413b, such that pin416and side links412a,412band center link414are generally secured together. The curved recessed portion or region413cis generally correspondingly formed with the mating surface416dof head portion416cto facilitate generally uniform engagement and generally smooth rotation between the head portion of the pin and the side links. Because the recessed portion413cand mating surface416dof head portion416care generally circular and are correspondingly formed, pin416is allowed to rotate relative to side links412a,412bas the chain moves along its conveying path, in order to substantially evenly distribute wear on the pin416and, thus, to extend the life cycle of the pin416.

Similar to the other ball members discussed above, ball member420of chain410allows for pivotal movement of center link414via sliding engagement of concave surface414balong ball member420. This provides greater flexibility to chain410and may allow the chain to negotiate sharper vertical curves in the conveying path without binding the links or joints of the chain. Chain410thus provides a pin which may negotiate sharper vertical turns and/or negotiate turns about different axes. The ball member and correspondingly formed concave surface thus may distribute the loads over a generally constant surface area, reducing or substantially eliminating the stress concentration that typically occur when conventional chains articulate through vertical inclines and declines. The ball member and concave surface engagement may also function to distribute the loads between the chain links and pin over a greater surface area than conventional chains. This decreases the wear on the bolt and chain links and may result in less maintenance and a greater life cycle for the chain.

Optionally, and with reference toFIG. 18A, the pin416′ may include threaded ends416b′ at opposite ends of the shaft portion416a′ and ball member420′. The threaded ends may be inserted through openings413′ in side links412a′,412b′ and retained therein via female fasteners or nuts418′. Similar to nut318′, discussed above, nuts418′ may include a chamfered or curved or rounded mating surface418a′ for engaging a generally correspondingly curved or rounded recess413a′ around opening413′ of side link412a′,412b′. The correspondingly formed surfaces allow for substantially smooth rotation of the pin relative to the side links. The pin416′ thus provides a rotatable bolted style pin with a ball member on the shaft portion of the pin, which may be readily assembled to the side and center links of a section of chain410′.

Referring now toFIGS. 19 and 20, a chain or section of chain410″ includes a pair of side links412a,412band a center link414′. The center link414′ is retained between the side links412a,412bby a rotatable pin416″ which extends through a center region414a′ of center link414′ and through an opening413in each side link412a,412b. Pin416″ includes a generally cylindrical shaft portion416a″, while center link414′ includes a generally flat or non-concave surface414b′ for engaging shaft portion416a″. Both head portions416c″ of pin416″ comprise a generally rounded and generally circular mating surface416d″, while side links412a,412binclude a correspondingly formed recessed area or region or engaging surface413cfor engaging mating surfaces416d″ to facilitate generally smooth rotation between pin416″ and side links412a,412b. Chain410″ may be otherwise substantially similar to chain410, discussed above, such that a detailed discussion will not be repeated herein. Optionally, pin416″ may include a generally cylindrical sleeve portion (not shown inFIGS. 19 and 20) formed or positioned around shaft portion416a″, such as discussed above or as discussed below.

It is further envisioned that a head portion of a pin of a section of chain may be non-circular shaped and the recessed portion of at least one of the side links may be correspondingly non-circular shaped, such that the head portion, and thus the pin, may be non-rotatably secured relative to the side link. For example, the head portion and a recessed region of a side link may be formed with two or more sides to provide for non-rotational engagement between the head and the recessed region, while allowing the head and bolt or pin to be manually rotated to adjust or change the wear surface engagement of the shaft and ball member with the center link. For example, the pin or bolt portion (shaft and head) of a bolted pin may be ratcheted or rotated sixty degrees or ninety degrees or some other amount (depending on the number of sides of the head and the recessed region) to provide a new wear surface of the shaft and ball member (the portion that engages the center link and wears as the links bend and turn relative to one another). The adjustable or dialable pin design of the present invention thus may provide for a significant increase in the life cycle of the pin, because the ball member (or spacer-ball-spacer assembly) may be replaced as needed, and/or the pin may be selectably rotated to provide a new wear surface as needed, which may substantially extend the overall life of the pin or bolted pin.

Each wear surface may span or cover approximately sixty or ninety or one hundred twenty degrees or the like about the pin, whereby the pin may be rotated that amount as necessary to provide six or four or three different wear surfaces or wear surface portions about the pin and, thus, to facilitate control of the amount of wear or amount of time of wear on each wear surface portion. This may be especially useful in applications where the chain is an exact pitch design (the chain length is specified with a small tolerance range), and excessive wear in one or more of the pins may affect the pitch, which may cause the chain to bind or chains to bind (if two such chains are running alongside one another with something connected or cradled between them) or may otherwise adversely affect the chain or conveyor. The pins of such a chain may then be dialed or rotated to provide a new wear surface for each pin, thereby effectively resetting the pins to their original tolerances and thus resetting the chain to its initial specified length. For example, each pin may be dialed to a second position or a third position or any other position to move a fresh wear surface to the wear position. In some cases, only a first pin or set of pins may need to be reset to provide an appropriate adjustment. Optionally, the degree of wear on the pin or shaft portion (or wear surface) may be monitored or determined, and the pin may be selectably rotated to limit wear on the wear surface of the pin. It is further envisioned that each station or lobe on the head portion of the pin may be marked or numbered to indicate which portion or portions of the wear surface have already been selected or used. The shaft of the pin may define at least one wear surface, and may define two or more distinct wear surfaces, such as discussed below with respect toFIGS. 41–64.

For example, and with reference toFIGS. 21 and 22, a head portion516cof a pin516and openings513bof side links512may be non-circular, such that pin516is non-rotatably positioned at and through side links512of a chain or section of chain510. For example, the head portion516cmay be lobed or non-circular shaped with three or more sides or portions516e(such as the three curved and generally equal-sized sides shown inFIGS. 21 and 22), with the recessed area513ccorrespondingly shaped to receive the head portion, such that the mating surfaces of the head portion516cwithin the correspondingly formed recessed area or impression513cin the side link512substantially precludes rotation of the pin516relative to the side links512. For example, one or more of the side portions of the head portion may engage a corresponding one or more of the sidewalls of the side link at the aperture to substantially preclude rotation of the pin relative to the side links. The wear surface of the shaft portion516aand/or ball member520thus may be generally fixed relative to the side links512by substantially fixing head516cwithin recess513c, such that only a portion of the shaft and/or ball member will contact and wear against the concave surface514bof the center link514as the chain travels along its conveying path.

The pin may be generally non-rotatable relative to the chain links when in each of the positions (such as in each of the three positions in the illustrated embodiment ofFIGS. 21 and 22, or such as in each of the six positions in the illustrated embodiment ofFIGS. 23–25, discussed below, or such as in any other number of positions suitable for such an arrangement), and may be selectably adjustable between the positions to adjust the wear surface of the shaft portion of the pin relative to the chain links, thereby providing selective engagement of a portion or portions of the wear surface with the chain links. Such an arrangement allows for controlling the wear and life cycle of the pin by wearing a particular wear surface of the pin at a time, and allows for controlled or manual or selective rotation from one wear surface of the pin to the next wear surface of the pin. The pin and side link arrangement of the present invention thus provides a dialable pin, which may be manually and selectably dialed or rotated to provide a new wear surface against the side link after the first wear surface has been sufficiently worn. Such a configuration facilitates control of the amount of time each wear surface or wear surface portion of the pin is in use.

Optionally, and with reference toFIGS. 23–25, a head portion516c′ of a pin516′ and openings513b′ of side links512′ may be non-circular, such that pin516′ is non-rotatably positioned at and through side links512′ of a chain or section of chain510′. As shown inFIGS. 23–25, the head portion516c′ may be generally hex-shaped, with the recessed area513c′ being correspondingly shaped to receive the head portion, such that the mating of the head portion516c′ within the correspondingly formed recessed area or impression513c′ in the side link512′ substantially precludes rotation of the pin516′ relative to the side links512′ in six positions. The wear surface of the shaft portion516a′ and/or ball member520′ may be generally fixed relative to the side links512′ by substantially fixing head516c′ within recess513c′, such that only a portion of the shaft and/or ball member will contact and wear against the concave surface514bof the center link514as the chain travels along its conveying path. The wear surface may then be adjusted or dialed to a new surface by rotating the pin516′ to a next orientation relative to the recesses513c′ in the side links512′, as discussed above.

Optionally, and with reference toFIGS. 26 and 27, a chain or section of chain510″ may include a pin516″, which may comprise shaped or lobed or hex-shaped head portions516c″ at opposite ends of a generally cylindrical shaft portion516b″. The center link514″ includes a generally flat or curved, non-concave surface514b″ for engaging the shaft portion516b″. Pin516″ and side links512′ may be otherwise substantially similar to pin516′ discussed above, such that a detailed discussion will not be repeated herein.

Optionally, and with reference toFIGS. 28–30, a chain or section of chain610may include a threaded pin or bolt616, which may comprise a shaft portion616aand a shaped or lobed or hex-shaped head portion616cat one end and a threaded portion616bat an opposite end for receiving a nut or threaded fastener or the like618(FIG. 30). Head portion616cmay be received in a correspondingly formed or shaped recess613cin one side link612a, while a generally cylindrical shaft portion616aand/or threaded end portion616bmay extend through an opening613in the other side link612bof chain610. The center link614includes a concave inner surface614bfor engaging a ball member620positioned along shaft portion616aof pin616. Ball member620may be formed as part of shaft portion616aor may be slid onto or formed or molded onto shaft portion616a, and pin616may include a generally cylindrical sleeve portion over and along shaft portion616a, such as any of the types of sleeves discussed above or below. Chain610may be otherwise substantially similar to chain510, discussed above, such that a detailed discussion will not be repeated herein.

Optionally, and with reference toFIGS. 31 and 32, a chain or section of chain610′ may include a threaded pin or bolt616′, which may comprise a shaft portion616a′ and a non-circular shaped or lobed or hex-shaped head portion616c′ at one end and a threaded portion616b′ at an opposite end for receiving a nut or threaded fastener or the like618. Head portion616c′ may be received in a correspondingly formed or shaped recess613cin one side link612a, while a generally cylindrical shaft portion616a′ and/or threaded end portion616b′ may extend through an opening613in the other side link612bof chain610′. The center link614′ may include a generally flat or non-concave inner surface614b′ for engaging shaft portion616a′ of pin616′. Optionally, pin616′ may include a generally cylindrical sleeve portion over and along shaft portion616a′, such as the types of sleeve portions discussed above or below. Chain610′ may be otherwise substantially similar to chain610, discussed above, such that a detailed discussion will not be repeated herein.

It is further envisioned that the shaft portions of the pins or studs or bolted pins may provide different or distinct wear surfaces when they are rotated or dialed to the next setting, in order to accommodate wearing at the wear surface of the center links or elsewhere in the chain links. The shaft portion thus may provide two or more different wear surfaces, with each particular wear surface corresponding to a dialable setting of the pin and head relative to the chain links. For example, each subsequent wear surface may be larger than (or have a larger radius relative to the center axis of the pin) the previous wear surface, in order to take up or account for any loss in dimensions of the wear surface of the center link. The shaft portion of the pin thus may be rotationally non-symmetrical or non-uniform, such that different wear surfaces may be provided by rotating or dialing the pin to the next setting. The wear surfaces may have different radii and may extend different amounts outward from the center axis of the shaft portion, such that the pin may effectively be a different size or radius by rotating or dialing the pin to the next setting, whereby an effective size or diameter of the shaft may be larger to replace a smaller effective size shaft, in order to accommodate the wear or erosion or deterioration of the wear surface of the center link. Each wear surface of the pin may correspond with a respective lobe or portion of the head portion of the pin, such that when a particular lobe is positioned in a particular part of the recess in the side link, the respective wear surface of the pin is generally aligned with the wear surface of the center link.

For example, and with reference toFIGS. 41–44, a chain or section of may include a pin1016, which may comprise a shaft portion1016aand opposite head portions1016b. Pin1016amay comprise an I-pin type of pin, and the head portions1016bmay be received in a correspondingly formed or shaped recesses in respective side links of the section of chain (such as the head portions of the pins ofFIGS. 9,10and21–32, discussed above), while the shaft portion1016aincludes at least one wear surface1017that engages a center link of the section of chain. The section of chain is not shown inFIGS. 41–44, but may be otherwise substantially similar to the chains or sections of chain described herein such that a detailed discussion will not be repeated herein. Shaft portion1016ais rotationally non-symmetrical or non-uniform, such that the wear surface1017of the shaft portion1016acomprises two distinct wear surfaces1017a,1017b, which are selectively positioned to engage the end portion of the center link. The different wear surfaces1017a,1017bprovide different surfaces at the center link when the pin is rotated or flipped 180 degrees.

For example, the pin1016may initially be positioned at the chain links such that wear surface1017aengages the center link. Wear surface1017aprovides a smaller radius surface or radius of curvature than wear surface1017b(which protrudes further outward from a center axis1016cof pin1016than wear surface1017a). After the wear surface1017ahas worn (and after the wear surface of the center link has also worn), the pin may be rotated 180 degrees such that wear surface1017bis positioned to engage the center link. The larger radius wear surface1017baccommodates any wear that may occur to the surface of the center link to provide similar overall dimensions of the chain links as compared to the initial dimensions (when the first wear surface1017awas initially positioned to engage the wear surface of the center link). The pin may be an I-pin as shown, or may be any other type of pin or threaded stud or bolt or the like or may have multiple lobes that correspond to the different wear surfaces, such as discussed below with respect toFIGS. 49–64, without affecting the scope of the present invention.

Optionally, and with reference toFIGS. 45–48, the pin1016′ may comprise an I-pin with a ball member1020positioned along the shaft portion1016a′. Ball member1020is rotationally non-symmetrical or non-uniform and comprises two wear surfaces1017a′,1017b′, which are selectively positioned to engage a wear surface or end portion of the center link of the section of chain. Pin1016′ and the chain section may be otherwise substantially similar to the pins and chains described herein such that a detailed discussion will not be repeated herein. The ball member may be integrally or unitarily formed as part of the shaft portion or may be fixedly or movably positioned on the shaft portion and/or may be molded onto the shaft portion or may receive the shaft portion therethrough, without affecting the scope of the present invention. Although shown and described as having a ball member with two wear surfaces, the ball member of the pin may provide three or more wear surfaces (such as described below with respect to pins1116and1216), without affecting the scope of the present invention. The pin may be an I-pin as shown or may be any other type of pin or threaded stud or the like or may have multiple lobes that correspond to the different wear surfaces, such as discussed below with respect toFIGS. 49–64, without affecting the scope of the present invention.

Optionally, and with reference toFIGS. 49–56, a chain or section of1110may include a pin or bolt1116, which may comprise a shaft portion1116aand a head portion1116bat one end and a threaded portion1116cat an opposite end for receiving a nut or threaded fastener or the like1118. Head portion1116bmay be received in a correspondingly formed or shaped recess1113ain one side link1112a, while shaft portion1116aand/or threaded end portion1116cmay extend through an opening1113bin the other side link1112bof chain1110. Head portion1116bmay be selectively received in the correspondingly formed or shaped recesses1113ain side link1112a, while the shaft portion1116amay engage a wear surface of a center link (not shown). Shaft portion1116ais rotationally non-symmetrical and comprises three distinct wear surfaces1117a,1117b,1117c, which engage the end portion or wear surface of the center link. Each wear surface1117a,117b,1117ccorresponds to a different lobe1116b′,1116b″,1116b′″ of head portion1116bto provide different surfaces at the center link when the pin is rotated approximately 120 degrees.

For example, the pin1116may be initially positioned at the chain links such that wear surface1117aengages the center link. Wear surface1117aprovides a smaller diameter surface than wear surface1117b(which protrudes radially further from a center axis1116dof pin1116than the first or smaller wear surface1117a), which in turn provides a smaller diameter surface than wear surface1117c(which protrudes radially further from center axis1116dthan second wear surface1117b). After the first wear surface1117ahas worn, the pin may be rotated 120 degrees such that lobe1116b″ (which may have a number “2” or other indicia printed or formed thereon to indicate the order of the wear surfaces of the pin) is at the end position of the link to align wear surface1117bwith the wear surface of the center link, and the pin may be further rotated or dialed to the third setting in a similar manner, as desired. The larger wear surface of the second or third setting accommodates any wear or erosion or deterioration or degradation that may occur to the surface of the center link during use of the chain with the pin at the previous setting, in order to provide similar overall dimensions of the chain links as compared to the initial dimensions. Chain1110may be otherwise substantially similar to the chains described herein such that a detailed discussion will not be repeated herein.

Optionally, and with reference toFIGS. 57–64, a chain or section of1210may include a pin or bolt1216, which may comprise a shaft portion1216aand a lobed head portion1216bat one end and a head portion or end portion1216cat an opposite end. Head portion1216bmay be received in a correspondingly formed or shaped recess1213ain one side link1212a, while shaft portion1216aand/or end portion1216cmay extend through an opening1213bin the other side link1212bof chain1210. Head portion1216bmay be selectively received in the correspondingly formed or shaped recesses1213ain side link1212a, while the shaft portion1216amay thus selectively engage a wear surface of a center link (not shown). As can be seen inFIGS. 57 and 58, the recess1213ain side link1212ahas slots or channels or recesses formed to receive the respective lobes of the head portion1216b. Preferably, the side link has an opening or aperture1213a′ next to or opposite to the end recess1213a″ that extends through the side link1212a, such that the lobe of the pin may slide along and through the opening to facilitate insertion of the head portion into the opening in the side link to facilitate assembly of the section of chain.

In the illustrated embodiment, the opposite head portion1216ccomprises a two-lobed head portion having lobes extending radially outwardly from a longitudinal axis of the pin in generally opposite directions from one another (such as is typically done at both ends of known I-pins and the like). Because head or end portion1216cis only a two-lobed head, head portion1216cmay be readily inserted through the openings1213a′,1213bin the side links and through the opening in the center link to assemble the section of chain. The pin1216thus provides an adjustable or dialable rivetless or non-bolted style pin that can be readily assembled to the chain links of a section of chain.

Optionally, the side link1212bmay include a recess or notch at the end of the opening1213band opposite to the end recess to provide support for one of the lobes of the head portion1216cwhen it is oriented with the lobes extending generally longitudinally along the side link. The lobes of the head portion1216cthus may be fully engaged with and supported by the recesses at the side link1212bin each of the four (or three or more) orientations that the pin may be set at when the pin and links are assembled together. Optionally, it is envisioned that the opening in one or both of the side links may be angled to allow for insertion of the two-lobed head portion1216c, while the surfaces of the recesses limit withdrawal of the pin from the side link when the pin is in any of the four positions of the lobed pin relative to the side links. For example, the side link1212bmay include an elongated opening that is oriented at about a forty-five degree angle relative to the longitudinal axis of the side link so that the pin head portion1216cmay insert through the opening and then may be rotated forty-five degrees in either direction to align the lobes with an engaging surface or recess of the side link while positioning the pin at a desired initial orientation relative to the chain links. Optionally, it is further envisioned that the lobes of the opposite head portion1216cmay be oriented at an angle relative to the lobes of the first head portion1216band then may engage recesses in the side link1212bthat are oriented at angles relative to the recesses at the other link1212awhen the pins and links are assembled together. Although shown on a pin having a four-lobed head portion, it is envisioned that the two-lobed head portion may be provided on a pin having a three lobed head portion or other types of dialable head portions, without affecting the scope of the present invention.

Shaft portion1216aof pin1216is rotationally non-symmetrical and comprises four wear surfaces1217a,1217b,1217c,1217d, which are selectively positioned to engage the end portion or wear surface of the center link. Each wear surface1217a,1217b,1217c,1217dcorresponds to a different lobe1216a′,1216a″,1216a′″,1216a″″ of head portion1216ato provide different surfaces at the center link when the pin is rotated approximately 90 degrees. For example, the pin1216may initially be positioned at the chain links such that wear surface1217aengages the center link (with lobe1216a′ positioned at recess1213a″ of side link1212a), and the pin may be rotated 90 degrees (to position lobe1216a″ at recess1213a″) after the pin and chain link have worn a sufficient or specified amount, and further rotated as further wear occurs. The different wear surfaces provide increasing effective diameters of the shaft of the pin, in order to accommodate wear or erosion or deterioration or degradation of the wear surface of the center link during use of the pin and chain, as described above with reference to pins1016,1116. Chain1210may be otherwise substantially similar to the chains described herein such that a detailed discussion will not be repeated herein.

In the illustrated embodiments, the pin may have an I-pin type head at its end opposite from the multiple lobed head or may have a threaded end for threadedly receiving a nut or fastener or the like to retain the pin at the side link, without affecting the scope of the present invention. As discussed above, the I-pin type head or two-lobed head allows the rivetless or non-bolted pin to be readily assembled to the chain links of the section of chain. However, it is envisioned that other head or end configurations, such as a three or four lobed head similar to the multi-lobed or dialable head portion of the pin may be incorporated at the opposite end of the pin or bolt or stud, without affecting the scope of the present invention. Also, although shown as having generally straight shaft portions, the shaft portion of the multiple wear surface pin may include a ball member that is rotationally non-symmetrical, such as described above, without affecting the scope of the present invention.

The dialable pin of the present invention thus may be rotated or dialed to the next position when the degree of wear on the engaged wear surface (the wear surface of the pin that is engaged with the wear surface of the center link) and/or the center link wear surface approaches or reaches approximately a predetermined amount. The degree of wear in the chain may be determined by detecting various points or locations along the chain as the chain is driven or moved along its path, in order to determine or estimate the degree of wear in the chain links or pins of the section or sections of chain between the detected points or locations. For example, a chain measurement or wear measurement device or system may detect points along a chain and calculate the distance between the points (such as by determining the distance between the points based on the speed of the chain and the time that elapses between the detections). As the distance between the points changes, the system may determine the wear in the pins or links for that chain section. The chain wear measurement device or system may detect any desired or appropriate or suitable location along the chain, or may detect the ends of the pins, such as at an extension at an end of one or more pins, such as is accomplished by the chain wear measurement device described in U.S. patent application, Ser. No. 10/356,063, filed Jan. 31, 2003 by Frost for WEAR MEASUREMENT DEVICE, and published Jul. 31, 2003 as U.S. publication No. US-2003-0140709-A1, which is hereby incorporated herein by reference. For example, a wear measurement system or device may include a sensor positioned along a conveying path of a conveyor system, where the sensor is operable to detect at least one of the pins (or other points or locations) of the section of chain as the chain is conveyed along the conveying path. The sensor generates a signal indicative of the detection of the pin (such as a detection of an extension from an end of one or more of the pins of the chain) or other location or locations along the chain. The pin or pins of the section of chain may be dialed or rotated to the next position to align the next or larger wear surface with the center link wear surface in response to an output of the wear measurement device or system, such as an output that is indicative of a particular degree of wear in a section or length of chain (as calculated or estimated in response to the detection of the ends of the pins or of other locations along the section of chain).

By providing a larger radius wear surface (or a new wear surface that protrudes further from a center axis of the pin from the previous wear surface and thus provides a larger effective diameter of the shaft of the pin) at the next selected or dialed wear surface of the pin, the degree of wear in the pin and links may be taken up or replaced with the larger wear surface when the pin is dialed or rotated to the next wear surface. The rotationally non-symmetrical or non-uniform wear surfaces of the pin may be designed to provide a particular increase in the effective diameter of the pin for each wear surface, such that the pin may be dialed to the next wear surface when a particular degree of wear (that may generally or substantially correspond with the particular increase in the wear surface of the pin) in the chain is detected by the wear measurement device. The dialable pin configuration, in conjunction with a chain wear measurement device or system, may thus be used to control the wear of the wear surfaces of the pin and chain links to maintain the chain at a desired working configuration, without having to replace the center link each time that the pin is rotated.

Also, the dialable pin configuration of the present invention may thus provide significantly greater life cycles for such chains and pins, since the pins do not have to be replaced when one or more of the pins wears a sufficient amount. Such a pin-head and side link design may be implemented with a pin with a ball member or the like or a pin with a generally cylindrical shaft portion and no ball member, without affecting the scope of the present invention. Also, such a dialable pin concept is suitable for use on a double headed pin or a single headed or bolted pin, with the head or heads of the pin being lobed or non-circular shaped or formed and engaged with a correspondingly formed recess in one of the side links, while a threaded end of a bolted pin may extend through a circular opening in the other side link and may be secured therein by a nut or other fastener, without affecting the scope of the present invention. Also, by providing a rotationally non-symmetrical or non-uniform wear surface on the shaft portion or ball member, the pin may accommodate wear or erosion or deterioration or degradation of the wear surface of the center link when the pin is rotated or dialed to provide the next wear surface of the shaft or ball member. The wear surfaces and degree of wear may be monitored by a wear measurement device or system to further control the wear of the chain.

The ball members and/or the concave surfaces of the center links of the present invention may comprise a metallic material, or may comprise a nylon or plastic or polymeric material, without affecting the scope of the present invention. The selected material is preferably a highly durable material which may minimize wear of the ball and/or the concave surface when the chain is in use and moving through various curves while under load.

Therefore, the present invention provides a bolted or pinned or half-bolted chain which has improved flexibility to ease negotiation of the chain links through sharp vertical changes in the chain path. The ball members of the present invention allow for pivotable movement between the center link and side links as the chain negotiates through the conveying path. More particularly, the ball member allows the center link to pivot about a longitudinal axis of the bolt, stud or pin in a conventional manner, while also allowing the center link to pivot about the ball member in other directions as well, such as pivoting upward or downward relative to the side links. The ball member and bolt or stud combination of the present invention thus allows the bolted chain to negotiate inclines along the conveying path without binding or excessive wear occurring at the chain joints. Also, the ball and socket type connection of the present invention allows the chain to flex about both axes, which further may allow the chain to twist or corkscrew over a sufficient length of track. Because the ball member may be loosely fit onto the bolt or stud, the ball member of the present invention provides for an easy assembly process of the bolt or stud and also facilitates easy disassembly or disconnection of the chain links for service or maintenance of the bolted chain. The present invention thus provides for a chain with much greater flexibility which is easy to manufacture and assemble.

Referring now toFIGS. 33 and 34, a chain or section of chain710includes a pair of side links712a,712band a center link714. The center link714is retained between the side links712a,712bby a pin716, such as an I-pin or other type of pin, bolt, stud or the like, which extends through a center region or opening714aof center link714and through an opening713ain each side link712a,712b. Pin716is retained in and through side links712a,712bby opposite head portions716aof pin716engaging a recessed region713bof a respective side link712a,712b. Pin716includes a generally spherical or toroidal-shaped ball member720which is molded around a shaft portion716bof pin716. Chain710includes multiple linkages connected together in a continuous loop about a conveying system, as is known in the art. For ease of description, only one set of linkages of the chain is shown and described herein, with the other linkages being substantially identical.

Shaft portion716bof pin716may comprise a metallic material, and may provide a substantially smooth exterior surface. The shaft portion716bmay be coated or treated, or may have a material deposited thereon, in a manner to provide a low coefficient of friction surface of the shaft portion. For example, the shaft portion may be treated with a TEFLON® coating or type material or a hard, carbon or diamond like material, or any other durable and low coefficient of friction material or slick material, without affecting the scope of the present invention. The low coefficient of friction or slick surface facilitates the breaking free of the molded sleeve or ball720(as discussed below) and further facilitates rotation or movement of the sleeve or ball720relative to the shaft of the pin as the chain negotiates through its conveying path. Although shown as an I-pin type fastener or connector, the side links712a,712band center714may be retained together via any other type of pin or bolt or stud for connecting the links of a chain, without affecting the scope of the present invention.

Each head portion716aof pin716may comprise a generally rectangular shaped head such that portions of the head716aextend laterally outward from the end of the shaft portion716bin opposite directions. Each side link712a,712bincludes a pair of slotted openings713awhich may be sized to receive head716atherethrough when the head is rotated approximately 90 degrees from the orientation shown inFIGS. 33 and 34, in order to facilitate assembly and disassembly of the chain links. Each side link712a,712bincludes a recessed region or pocket713bat each end for head716aof pin716to rest when the chain is assembled. The recessed region713bis defined by a raised end portion713cand raised inward portions713dwhich engage the sides of the head716ato substantially preclude rotation of the pin716relative to side links712a,712band center link714.

Center link714may comprise a generally oval shaped or elongated ring defining inner opening714a. Center link714includes an inner rounded or concave surface714b(FIGS. 33 and 34) at each end thereof for engaging and partially receiving ball member720therein to retain center link714at ball member720as the chain is moved along the conveying path. Optionally, concave surface714bmay be coated or treated with a low coefficient of friction material, similar to shaft portion716bof pin716discussed above, to reduce the friction between ball member720and center link714.

Ball member720may comprise a plastic or polymeric member which is molded onto the substantially smooth metallic shaft portion716bof pin716. Ball member720is molded around the shaft portion716bafter pin716is formed and is then allowed to cool and harden around the shaft portion. Because shaft portion716bhas a substantially smooth, and preferably slick, outer surface, ball member720may be twisted, slid, or otherwise moved relative to shaft portion716bto break ball member720free from shaft member716b. Ball member720may then be freely rotatable and movable around and along shaft portion716bto allow for relative movement between ball member720and pin716. Ball member716thus provides a unitarily formed ball which is movable relative to pin716and center link714. Ball member716may include one or more spacers or sleeve portions extending from one or both ends of the ball member, such as discussed above, to assist in retaining the ball member in place along the shaft portion.

Ball member720may be formed by injection molding a polymeric material around the shaft portion716bof pin716or may be formed via any other molding process or method, without affecting the scope of the present invention. Ball member720may be formed of a durable, hard polymeric material, such as a nylon material or filled nylon material, a PBT material, or an engineering plastic or the like. Clearly, however, other materials may be used for ball member720, without affecting the scope of the present invention.

Optionally, ball member720may provide an exterior surface which has a durable and low coefficient of friction to also enhance the relative movement between ball member720and center link714. Optionally, ball member720may be coated with a slick or low coefficient of friction material, similar to shaft portion716bdiscussed above, to further reduce the friction between the components, without affecting the scope of the present invention.

Ball member720thus allows for pivotal movement of center link714via sliding engagement between ball member720and shaft portion716bof pin716and/or sliding engagement between concave surface714band ball member720. This provides greater flexibility to chain710and may allow chain710to negotiate sharper vertical curves in the conveying path without binding the links or joints of the chain. The ball member and correspondingly formed concave surface thus may distribute the loads over a generally constant surface area, reducing or substantially eliminating the stress concentration that typically occur when conventional chains articulate through vertical inclines and declines. The ball member and concave surface engagement may also function to distribute the loads between the chain links and pin over a greater surface area than conventional chains. This decreases the wear on the pins and chain links and may result in less maintenance and a greater life cycle for the chain. Also, because chain710may provide a low coefficient of friction surface at shaft716bof pin716and/or at center link714, ball member720may provide for a reduced amount of friction between the center link714and pin716, which may further reduce wear on the components and may result in even less maintenance and an even greater life cycle of the chain.

Referring now toFIG. 35, a chain or section of chain710′ includes side links712a,712band a center link714, which are retained together by a pin716′. Side links712a,712band center link714may be substantially similar to the side links and center link discussed above with respect to chain710, such that a detailed discussion of these components will not be repeated herein.

Pin716′ includes head portions716a′, similar to pin716, and a shaft portion716b′ extending between the opposite head portions716a′. Shaft portion716b′ comprises a generally cylindrical shaft portion and includes a notched or narrowed section716c′ at a central region thereof. Notched section716c′ of pin716′ may extend circumferentially around shaft portion716b′, so as to define a narrowed diameter central region of shaft portion716b′. However, notched section716c′ may optionally provide separate notched portions or indents or grooves in a portion of the central region of the shaft portion, without affecting the scope of the present invention.

Similar to pin716, discussed above, shaft portion716b′ and notched section716c′ of pin716′ may provide substantially smooth, cylindrical exterior surfaces. Shaft portion716b′ may be coated or treated in a manner to provide a low coefficient of friction surface of the shaft portion, such as described above with respect to pin716of chain710. The low coefficient of friction or slick surface facilitates the breaking free of a molded sleeve or ball720′ (discussed below) and further facilitates rotation or movement of the sleeve or ball720′ relative to the shaft of the pin as the chain negotiates through its conveying path. Although shown as an I-pin type fastener or connector, the links712a,712band714may be retained together via any other type of pin or bolt or stud, such as formed using the principles described above, for connecting the links of a chain, without affecting the scope of the present invention.

Pin716′ includes a generally spherical or toroidal-shaped ball member720′ around shaft portion716b′ of pin716′. Ball member720′ may comprise a plastic or polymeric member which is molded onto the substantially smooth shaft portion716b′ of pin716′, such that an inner portion of ball member720′ is molded within notched section716c′ of pin716′. Ball member720′ is molded around the shaft portion716b′ after pin716′ is formed and is then allowed to cool and harden around the shaft portion. Because shaft portion716b′ and notched section716c′ may have a substantially smooth and cylindrical outer surface, and which may be treated with a slick material or coating, ball member720′ may be twisted or otherwise moved relative to shaft portion716b′ to break ball member720′ free from shaft member716b′. Ball member720′ may then be freely rotatable around and notched section716c′ of shaft portion716b′ to allow for relative movement between ball member720′ and pin716′. Notched section716c′ functions to retain ball member720′ in place and limits or substantially precludes longitudinal movement of ball member720′ along shaft portion716b′ of pin716′.

Similar to ball member720, ball member720′ may be formed by injection molding a polymeric material around the shaft portion716b′ of pin716′ or may be formed via any other molding process or method, without affecting the scope of the present invention. Optionally, ball member720′ may provide an exterior surface which is durable and which may have a low coefficient of friction to enhance the relative movement between ball member720′ and center link714. Optionally, ball member720′ may be coated with a slick or low coefficient of friction material, such as discussed above with respect to ball member720, to further reduce the friction between the components. As discussed above, concave surface714bof center link714may also or otherwise be coated or treated to provide a surface having a lower coefficient of friction for engagement with ball member720′.

Referring now toFIG. 36, a chain or section of chain810includes side links712a,712band a center link714, which are retained together by a pin816. Side links712a,712band center link714may be substantially similar to the side links and center link discussed above with respect to chain710, such that a detailed discussion of these components will not be repeated herein.

Pin816includes opposite head portions816a, similar to pin716, and a shaft portion816bextending between the opposite head portions816a. Shaft portion816comprises a generally cylindrical shaft portion and includes a spherical or toroidal-shaped ball member820integrally formed at a generally central region thereof. Similar to pin716, discussed above, shaft portion816band ball member820of pin816may provide a substantially smooth exterior surface. Shaft portion816band ball member820may be coated or treated in a manner to provide a low coefficient of friction surface, such as described above with respect to pin716of chain710. The low coefficient of friction or slick surface facilitates the breaking free of a molded sleeve817(discussed below) from the shaft portion and ball member of pin816and further facilitates rotation or movement of the sleeve relative to the shaft and ball of the pin as the chain negotiates through its conveying path. Although shown as an I-pin type fastener or connector, the links712a,712band714may be retained together via any other type of pin or bolt or stud for connecting the links of a chain, such as formed using the principles discussed above, without affecting the scope of the present invention.

Pin816includes a polymeric or plastic sleeve portion817molded around shaft portion816band ball member820. The slick surface of the shaft portion816band ball member820allows sleeve portion817to be broken free from shaft portion816bafter sleeve portion817is molded thereon, and allows for rotation of sleeve portion817about shaft portion816band ball member820. Optionally, sleeve portion817may provide a highly durable and slick or low friction surface for engagement of sleeve817with the concave surface714bof center link714. As can be seen inFIG. 36, sleeve portion817may extend along shaft portion816bto head portions816a, such that sleeve portion817also provides a highly durable and optionally slick or low friction surface for engagement between shaft portion816band the end walls713eof openings713aof side links712a,712b.

Similar to ball members720and720′, sleeve portion817may be molded over shaft portion816bafter pin816has been formed. Because shaft portion816band ball member820of pin816provide a substantially smooth surface and may have a treated slick surface at which sleeve portion817is molded, the sleeve portion may be twisted or otherwise moved relative to pin816to break the molded sleeve portion away from shaft portion816band ball member820, such that sleeve portion817may be generally freely rotatable about shaft portion816band ball member820. When chain810is assembled, sleeve portion817may thus be movable relative to side links712a,712b, center link714and pin816as the chain flexes or bends through its conveying path.

Similar to ball member720, sleeve portion817may be formed by injection molding a polymeric material around the shaft portion816band ball member820of pin816or may be formed via any other molding process or method, without affecting the scope of the present invention. Optionally, sleeve portion817may provide an exterior surface (or may be treated with a material or coating) which has a low coefficient of friction to enhance the relative movement between sleeve portion817and center link714, such as discussed above with respect to ball member720. As discussed above, concave surface714bof center link714may also or otherwise be coated or treated to provide a surface having a lower coefficient of friction for engagement with sleeve portion817.

Referring now toFIG. 37, a chain or section of chain810′ includes side links712a,712band a center link714′, which are retained together by a pin816′. Side links712a,712band center link714′ may be substantially similar to the side links and center link discussed above with respect to chain710, such that a detailed discussion of these components will not be repeated herein. However, center link714′ of chain810′ may have a generally straight or slightly curved pin engaging surface714b′ at its ends, and does not include a concave pin engaging surface.

Pin816′ includes opposite head portions816a′, similar to pin716, and a shaft portion816b′ extending between the opposite head portions816a′. Shaft portion816′ comprises a generally cylindrical shaft and preferably provides a substantially smooth exterior surface. Shaft portion816b′ may be coated or treated in a manner to provide a low coefficient of friction surface of the shaft portion, such as described above with respect to pin716of chain710. For example, the shaft portion may be treated with a TEFLON® coating or type material or a hard, diamond like material or any other low coefficient of friction material or slick material, without affecting the scope of the present invention, to substantially reduce the friction between the components. The low coefficient of friction or slick surface facilitates the breaking free of a molded sleeve817′ and further facilitates rotation or movement of the sleeve relative to the shaft of the pin as the chain negotiates through its conveying path. Although shown as an I-pin type fastener or connector, the links712a,712band714′ may be retained together via any other type of pin or bolt or stud for connecting the links of a chain, such as formed using the principles discussed above, without affecting the scope of the present invention.

Pin816′ includes a polymeric or plastic sleeve portion817′ molded around shaft portion816b′. Optionally, sleeve portion817′ may provide a highly durable and slick or low friction surface for engagement of sleeve portion817′ with the surface or end714b′ of center link714′. As can be seen inFIG. 37, sleeve portion817′ may extend along shaft portion816b′ to head portions816a′, such that sleeve portion817′ may also provide a highly durable (and optionally a slick or low friction surface) for engagement of shaft portion816b′ with the end walls713eof openings713aof side links712a,712b. As discussed above, the end of center link714′ may also or otherwise be coated or treated to provide a surface having a lower coefficient of friction for engagement between sleeve portion817′ and center link714′.

Similar to ball members720and720′ and sleeve portion817, sleeve portion817′ is molded over shaft portion816b′ after pin816′ has been formed. Because shaft portion816b′ of pin816′ provides a substantially smooth and slick surface at which sleeve portion817′ is molded, the sleeve portion may be twisted or otherwise moved relative to pin816′ to break the sleeve portion away from shaft portion816b′, such that sleeve portion817′ may be generally freely rotatable about shaft portion816b′. When chain810′ is assembled, sleeve portion817′ is movable relative to side links712a,712b, center link714′ and pin816′ as the chain flexes or bends through its conveying path. Similar to ball member720, sleeve portion817′ may be formed by injection molding a polymeric material around the shaft portion816b′ of pin816′ or may be formed via any other molding process or method, without affecting the scope of the present invention.

As shown inFIG. 38, a chain or section of chain910may include a pin916and side links (not shown) and a center link914. Center link914includes a plastic or polymeric insert or member915at each end for engagement with the shaft portion916bof pin916. The plastic insert915may be coated or treated with or may otherwise provide a durable and slick or low friction material surface for engagement between plastic insert915of center link914and pin916. Insert915may be molded at an end914bof center link914, such as via an injection molding process or the like. However, insert915may be molded to center link914via other molding means, or may be snapped or removably mounted or affixed to center link914, without affecting the scope of the present invention.

Pin916includes opposite head portions916aand shaft portion916bextending between the opposite head portions916a. Shaft portion916may comprise a generally cylindrical shaft and may provide a substantially smooth exterior surface. Similar to pin716, shaft portion916may be coated or treated in a manner to provide a slick or low coefficient of friction surface. However, other pins; bolts, studs or the like may be implemented with chain910, without affecting the scope of the present invention.

Each end914bof center link914provides a recessed area914c, such that insert915may be molded or retained generally within recessed area914cand may be substantially fixed or non-movable within recessed area914c. In the illustrated embodiment, recessed area914cprovides a pair of raised end stops914dat opposite ends of a generally octagonal, curved surface914e. The octagonal surface914eand end stops914dfunction to substantially preclude movement of insert915relative to center link914after insert915has been molded thereto. Although shown as an octagonal shaped surface, clearly, other shapes may be provided at recessed area914cto limit or substantially preclude movement of insert915relative to center link914.

Insert915may provide a durable and low coefficient of friction surface915afor engagement with shaft portion916bof pin916. The low coefficient of friction surface may provide enhanced relative movement between pin916and center link914, which may reduce wear on the center link and pin as the chain negotiates through the conveying path. Insert915may be made from a durable polymeric or plastic material, such as a nylon material, such as a filled nylon material, a PBT material, or an engineering plastic or the like. Optionally, the insert915and/or the shaft portion916bof pin916may be treated or coated with a material which provides a low coefficient of friction to enhance relative movement between the pin and the center link and to reduce the wear on the components to increase the life cycle of the chain.

Although shown as being implemented with a cylindrical shaft pin, it is envisioned that an insert in accordance with the present invention may include a concave surface (not shown inFIG. 38), such as a surface similar to concave surface714bof center link714, discussed above, for engagement with a ball member or other sleeve or the like (also not shown inFIG. 38) on the shaft portion of the pin, such as a ball member or sleeves of the types discussed above or the like. The insert may be removably mounted or affixed to the center link to facilitate removal and replacement of the insert to provide a center link with a replaceable wear surface.

Referring now toFIG. 39, a chain or section of chain910′ includes a pin916′, side links912′ and a center link914′. Center link914′ includes a plastic or polymeric insert or member915′ at each end for engagement with the shaft portion916b′ of pin916′. The plastic insert915′ may be coated or treated with or may otherwise provide a durable and slick or low friction material surface for engagement between center link914′ and pin916′. Insert915′ may be molded at an end914b′ of center link914′, such as via an injection molding process or the like. However, insert915′ may be molded to center link914′ via other molding means, without affecting the scope of the present invention. Optionally, insert915′ may be a replaceable insert which may be snapped or otherwise affixed to the end914b′ of the center link914′. Insert915′ may include a concave engagement surface or socket915a′ for generally uniformly engaging an outer surface of a ball portion or member920′ of pin916′, discussed below.

Pin916′ includes opposite head portions916a′ and shaft portion916b′ extending between the opposite head portions916a′. Shaft portion916′ comprises a generally cylindrical shaft and includes generally spherical ball member or portion920′ at a generally central portion of shaft portion916b′. Ball member920′ may be formed as part of the shaft of pin916′ or may be slid or molded or formed onto pin916′, such as utilizing the principles discussed above or the like. The outer surface of shaft portion916b′ and ball portion920′ preferably provides a substantially smooth exterior surface for engagement with insert915′ at center link914′. Similar to pin716, shaft portion916b′ and ball portion920′ of pin916′ may be coated or treated in a manner to provide a slick or low coefficient of friction surface. However, other pins, bolts, studs or the like may be implemented with chain910′, without affecting the scope of the present invention.

Similar to center link914, discussed above, each end914b′ of center link914′ may provide a recessed area (shown generally at914c′), such that insert915′ may be molded generally within the recessed area and may be substantially fixed or non-movable within the recessed area. Recessed area914c′ may be generally similar to recessed area914cdiscussed above, such that a detailed discussion of the recessed area will not be repeated herein. Recessed area914c′ of center link914′ may include a concave mating surface or socket, which generally corresponds to the curvature of socket or surface915a′ of insert915′. The insert915′ may then be molded to have a generally uniform thickness at the socket area. However, the center link914′ may have a generally flat or otherwise formed mating surface for the insert915′, without affecting the scope of the present invention.

Insert915′ may provide a durable and low coefficient of friction surface915a′ for engagement with ball member or portion920′ of pin916′. The low coefficient of friction may provide enhanced relative movement between pin916′ and center link914′, which may reduce wear on the center link and pin as the chain negotiates through the conveying path. The corresponding shapes or curvature of the surface915a′ and ball member920′ provides for enhanced flexibility of chain910′, with reduced wear on the ends of center link914′ and/or on the shaft of pin916′. Insert915′ may be made from a durable polymeric or plastic material, such as a nylon material, such as a filled nylon material, a PBT material, or an engineering plastic or the like. The ball and socket arrangement minimizes any tension and shear stresses on the insert915′, such that insert915′ may be exposed primarily to compression loads, which are less damaging to the plastic insert. Optionally, the insert915′ and/or the ball portion920′ of pin916′ may be treated or coated with a material which provides a low coefficient of friction to enhance relative movement between the pin and the center link and to reduce the wear on the components to increase the life cycle of the chain.

Optionally, as shown inFIG. 40, a chain or section of chain910″ may include a pin916″, side links912″ and a center link914″. Center link914″ includes a plastic or polymeric insert or member915″ at each end for engagement with the shaft portion916b″ of pin916″. The plastic insert915″ may be coated or treated with or may otherwise provide a durable and slick or low friction material surface for engagement between center link914″ and pin916″. Insert915″ may be molded at an end914b″ of center link914″, such as via an injection molding process or the like. However, insert915″ may be molded to center link914″ via other molding means, without affecting the scope of the present invention. Insert915″ may include a convex engagement surface915a″ for generally uniformly engaging a narrowed, outer surface of shaft portion916b″ of pin916″, as discussed below.

Pin916″ includes opposite head portions916a″ and shaft portion916b″ extending between the opposite head portions916a″. Shaft portion916″ comprises a generally cylindrical shaft and includes a narrowed portion916c″ at a generally central portion of shaft portion916b″. Narrowed portion916c″ provides an inwardly curved surface for generally uniform engagement with the outwardly curved surface915a″ of insert915″. The outer curved surface916c″ of shaft portion916b″ may provide a substantially smooth exterior surface for engagement with convex surface915a″ of insert915″ at center link914″. Similar to pin716, shaft portion916″ may be coated or treated in a manner to provide a slick or low coefficient of friction surface. However, other pins, bolts, studs or the like may be implemented with chain910″, without affecting the scope of the present invention.

Center link914″ may be substantially similar to center links914,914′, discussed above, such that a detailed discussion of the center link914″ will not be repeated herein. Suffice it to say that insert915″ may be molded generally within a recessed area at each end of center link914″ and may be substantially fixed or non-movable within the recessed area. Optionally, the insert may be snapped or otherwise affixed to or removably mounted to the center link and may provide a removable and replaceable wear surface for the center link.

Similar to inserts915and915′, insert915″ may provide a durable and low coefficient of friction surface915a″ for engagement with the narrowed curved portion916c″ of shaft916b″ of pin916″. The low coefficient of friction provides enhances relative movement between pin916″ and center link914″, which may reduce wear on the center link and pin as the chain negotiates through the conveying path. The corresponding shapes or curvature of the outwardly curved surface915a″ of insert915″ and the inwardly curved surface916c″ of pin916″ provides for enhanced flexibility of chain910″, with reduced wear on the ends of center link914″ and/or on the shaft of pin916″. Insert915″ may be made from a durable polymeric or plastic material, such as a nylon material, such as a filled nylon material, a PBT material, or an engineering plastic or the like. Optionally, the insert915″ and/or the curved surface916c″ of pin916″ may be treated or coated with a material which provides a low coefficient of friction surface or coating to enhance relative movement between the pin and the center link and to reduce the wear on the components to increase the life cycle of the chain.

Although each of the embodiments of chain sections discussed above with respect toFIGS. 33–40includes a pin with oval or rectangular head portions, it is further envisioned that a round-headed pin may be provided (such as with any of the chains of the present invention discussed above) with a rounded head at each end of the pin and a ball member and/or sleeve or the like on the shaft portion between the heads. The head portions may then insert through enlarged, generally circular openings in the side links and may slide outwardly toward the ends of the side links to a narrowed opening. The narrowed opening substantially precludes the circular heads from moving therethrough, and thus retains the side links relative to the center links and the pin. The side links include a recessed area around the narrowed opening to receive the rounded head therein to substantially preclude movement of the pin relative to the side links toward the enlarged openings in the side links. The pin is thus allowed to rotate relative to the side links and the center link, while allowing greater flexibility and/or reduced wear of the chain.

Although shown as being joined by a pin inFIGS. 33–40, it is further envisioned that the linkages of the chains of the present invention may otherwise be joined by other pins, bolts, studs, half-bolt/half-pin type pins or fasteners, or any other fastening or joining means for retaining the side links and the center links together. The fastening or joining means may be formed using the principles discussed above.

It is envisioned that any of the pin and chain link embodiments discussed above may have wear surface components comprising any suitable material. For example, the wear surface components may comprise steel or other metallic material, bronze or other softer metallic material, a polymeric material, such as engineering plastics or other strong and durable polymeric material, a ceramic material, a sintered material, a TEFLON® coating or material, a fluorocarbon material or the like. It is also envisioned that any of the pin and chain link embodiments discussed above may include a low coefficient of friction or slick coating at or on the wear surfaces of the pins and/or chain links. The coating thus may provide enhanced relative movement or rotation or sliding between the wear surfaces to enhance performance of the section of chain and to increase the life cycle of the section of chain. The coating may comprise a TEFLON® type coating or a diamond like coating or the like or any other low coefficient of friction or slick coating or the like suitable for such an application.

The present invention thus may provide a diamond like coating (DLC) over a metallic or plastic (or other material) wear surface of the pin or chain link. The wear surface component may define a substantially smooth wear surface to enhance sliding or moving engagement with a corresponding wear surface of the section of chain. The metallic wear surface component or components may be formed to be substantially smooth via any known means, such as via tumbling, vibrating or the like of the component, such as tumbling with ceramic chips or steel chips or the like, while the plastic wear surface component or components may be molded to the desired form and/or tumbled or vibrated to achieve the desired surface smoothness, without affecting the scope of the present invention.

The diamond like coating on the wear surface or surfaces provides enhanced performance and an increased life cycle to the section of chain. Because such a diamond like coating may be sensitive to point loading and shock in some applications, the wear surface components of the present invention may comprise a ball member and a correspondingly formed socket to reduce or substantially eliminate such point loading conditions. Such ball and socket arrangements reduce such shock or impact or point loading concerns by spreading out the contact area over a wider area.

Therefore, the present invention provides a sleeve and/or a ball member and a pin or bolt or stud which allows for pivotal movement of the center link via sliding engagement of the center link along the ball member and via sliding engagement of the sleeve or ball member around the shaft of the pin. This provides greater flexibility to the chain and may allow the chain to negotiate sharper vertical curves in the conveying path without binding the links or joints of the chain. The ball member and correspondingly formed concave surface thus may distribute the loads over a generally constant surface area, reducing or substantially eliminating the stress concentration that typically occur when conventional chains articulate through vertical inclines and declines. The ball member and concave surface engagement may also function to distribute the loads between the chain links and pin or bolt or stud over a greater surface area than conventional chains. This decreases the wear on the pin and chain links and may result in less maintenance and a greater life cycle for the chain.

The ball member, and/or the sleeve over the ball member or shaft of the pin, and/or the insert at the center link may comprise a high strength, durable polymeric or plastic material. The selected material may comprise a highly durable material which may minimize wear of the ball member and/or the concave surface when the chain is in use and moving through various curves while under load. The material may be selected or treated or coated to also provide a low coefficient of friction surface to enhance movability of the components relative to one another and to reduce wear on the components. Optionally, one or more of the contacting surfaces may be treated or coated with a material which may provide a low coefficient of friction surface between the contacting components to further reduce wear on the chain. The ball member, sleeve, insert or other wear surface component may optionally comprise a metallic material, such as steel or the like or bronze or other softer metallic or the like, and may be coated or treated to enhance the low friction engagement between respective wear surfaces. Because the ball member, pin and/or center link of the present invention may include a low friction surface, the present invention provides for a reduced amount of friction between the center link and the pin and/or between the side links and the pin, which further reduces wear on the components and may result in less maintenance and a greater life cycle of the chain. It is envisioned that the low friction surfaces of the present invention may substantially reduce or obviate the need for lubrication of the joints of the chain during use. The present invention thus may provide a non-lubricated chain with plastic components.

The present invention also provide for a unitary plastic component formed or molded onto a pin to enhance the performance of the chain. The molded ball member or sleeve may be broken free from the pin to allow relative movement between the pin and the ball member or sleeve while also allowing relative movement between the ball or sleeve and the chain links. The molded ball or sleeve is thus a unitarily formed, durable member which provides an engagement component between the metal components of the chain. Optionally, a metal or plastic ball or sleeve may be slid or pressed onto a stud or bolt type pin and may be removable therefrom.

The present invention thus provides a chain which has improved flexibility to ease negotiation of the chain links through sharp vertical changes in the chain path. The ball member or the narrowed shaft portion of the present invention allows for pivotable movement between the center link and side links as the chain negotiates through the conveying path. More particularly, the ball member or narrowed shaft portion allows the center link to pivot about a longitudinal axis of the pin in a conventional manner, while also allowing the center link to pivot relative to the pin, such as about the ball member or within the curved shaft portion, in other directions as well, such as pivoting upward or downward relative to the side links. The ball member/curved engagement surface and pin combination of the present invention thus allows the chain to negotiate inclines along the conveying path without binding or excessive wear occurring at the chain joints. Also, the ball and socket type connection of the present invention allows the chain to flex about both axes, which further may allow the chain to twist or corkscrew over a sufficient length of track. The present invention thus provides for a chain with much greater flexibility and greater life cycles which is easy to manufacture and assemble.