Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/03—Powdery paints
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G17/00—Conveyors having an endless traction element, e.g. a chain, transmitting movement to a continuous or substantially-continuous load-carrying surface or to a series of individual load-carriers; Endless-chain conveyors in which the chains form the load-carrying surface
  • B65G17/06—Conveyors having an endless traction element, e.g. a chain, transmitting movement to a continuous or substantially-continuous load-carrying surface or to a series of individual load-carriers; Endless-chain conveyors in which the chains form the load-carrying surface having a load-carrying surface formed by a series of interconnected, e.g. longitudinal, links, plates, or platforms
  • B65G17/08—Conveyors having an endless traction element, e.g. a chain, transmitting movement to a continuous or substantially-continuous load-carrying surface or to a series of individual load-carriers; Endless-chain conveyors in which the chains form the load-carrying surface having a load-carrying surface formed by a series of interconnected, e.g. longitudinal, links, plates, or platforms the surface being formed by the traction element
  • B65G17/086—Conveyors having an endless traction element, e.g. a chain, transmitting movement to a continuous or substantially-continuous load-carrying surface or to a series of individual load-carriers; Endless-chain conveyors in which the chains form the load-carrying surface having a load-carrying surface formed by a series of interconnected, e.g. longitudinal, links, plates, or platforms the surface being formed by the traction element specially adapted to follow a curved path
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/03—Powdery paints
  • C09D5/033—Powdery paints characterised by the additives
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G2207/00—Indexing codes relating to constructional details, configuration and additional features of a handling device, e.g. Conveyors
  • B65G2207/12—Chain pin retainers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G2207/00—Indexing codes relating to constructional details, configuration and additional features of a handling device, e.g. Conveyors
  • B65G2207/26—Hygienic features, e.g. easy to sanitize
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G2207/00—Indexing codes relating to constructional details, configuration and additional features of a handling device, e.g. Conveyors
  • B65G2207/48—Wear protection or indication features
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T24/00—Buckles, buttons, clasps, etc.
  • Y10T24/16—Belt fasteners
  • Y10T24/1608—Hinged
  • Y10T24/1628—Overlapped belt ends
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/49826—Assembling or joining

Definitions

• This invention relates generally to the conveyor art and, more particularly, to a wear- resistant connector for connecting modular links to form a conveyor belt.
• modular link conveyors in industry enjoys increasing popularity. Particularly for conveying food articles or consumer products, especially in packages or in semi-packaged form, the modular link conveyor represents the overwhelming choice of those in the industry looking for a long-lasting, low cost conveying solution. In the recent past, significant advances in the development of such have been made so as to provide more efficient handling of an even larger variety of food articles, packages and containers, as well as other types of articles and products.
• 6,648,129 to Sedlacek describes a "two material" hinge pin arrangement in which a rod made of a rigid material (such as steel) slidably receives a urethane outer tube.
• the urethane tube forms a high friction material that preferably rotates relative to the underlying rod to facilitate articulation (ostensibly as the result of particles becoming embedded in the space between the tube and the rod).
• the high friction surface of the outer tube may actually cause significant wear on the links, as well as the underlying rod in the event of relative rotation.
• the rod should be exceptionally strong and resistant to the effects of creep, while also being suitable for use in even the most sensitive of conveying environments (including those in which food is transported).
• the rod should also be easy and inexpensive to manufacture using existing techniques, and thus would not contribute significantly to the cost of the overall conveyor system (which can include hundreds or thousands of these rods) or its wear.
• the rod should also be usable with existing conveyors, such as in a retrofit situation, without changing the design or principles of operation.
• a first part includes a surface subjected to wear as the result of sliding frictional contact with a second part.
• the improvement comprises a powder coating applied to the surface of the first part.
• the powder coating serves to reduce friction between the first and second parts, provide enhanced wear resistance to the first part, and improve cleanability of the first part.
• the first part comprises metal, such as stainless steel
• the powder coating comprises a polyamide, such as nylon
• the second part comprises a polymer material, such as acetal.
• the second part comprises a link of a chain and the first part comprises a connector for engaging the link such that sliding friction results between the first and second parts.
• the link may include an opening for receiving the connector such that an outer surface of the connector including the powder coating frictionally engages a surface of the link within the opening.
• both the first and second parts are moving relative to each other, but possibly only one of the first or second parts is fixed and the other is moving.
• a connector for connecting links of a conveyor belt comprises an elongated core.
• a powder coating forms a shell on a surface of the core.
• the core comprises steel and, preferably, stainless steel.
• the shell comprises nylon.
• the shell may comprise a material selected from the group consisting of PROTECH CHEMICAL LTD. Mercury Blue hybrid, SHERWIN WILLIAMS Whitewater polyester, SHERWIN WILLIAMS Antique White hybrid, THERMOCLAD White DURALON 12 (Nylon 12), THERMOCLAD Clear DURALON 12 (Nylon 12), SHERWIN WILLIAMS Furniture White polyurethane, and RILSAN nylon.
• the shell is generally clear, but maybe white in color, and further comprises a polymer material including an anti-microbial, anti-bacterial, anti-fungal, or germicidal agent.
• an elongated connector for connecting links in a conveyor belt.
• the connector comprises a rod-like mild or stainless steel core.
• a nylon coating such as an extruded tube or powder coated shell, is provided on a surface of the core.
• a conveyor belt section comprises a plurality of links interconnected by an elongated connector.
• the connector comprises a rod-like body including a metal core and a powder coating forming a shell.
• the links comprise acetal
• the metal core comprises stainless steel
• the powder coating comprises nylon.
• a conveyor belt is disclosed.
• the belt comprises a plurality of links arranged in interdigitated rows and an elongated connector for connecting the links.
• the connector comprises a core and a powder coating forming an outer shell on the core.
• Still another aspect of the invention is a method of forming a connector for the links in a conveyor belt.
• the method comprises powder coating a rod to form an outer protective shell on a surface of the rod.
• the method involves powder coating nylon on a steel or stainless steel rod, such as by electrostatically applying nylon powder to a surface of the rod and then heating the rod to cure the powder and form a protective shell.
• Yet a further aspect of the invention is a method of manufacturing a conveyor belt section from a plurality of interdigitated links.
• the method comprises coating a surface of a connector with a powder coating and connecting the interdigitated links with the coated connector.
• the coating step comprises electrostatically applying a nylon powder to a surface of the connector and then heating the connector (such as for a period greater than about 15 minutes and at a temperature greater than about 400 0 F).
• the coating step comprises placing nylon over an entire outer surface of the connector, which is preferably a metal rod.
• a method for manufacturing a conveyor belt section from a plurality of interdigitated links.
• the method comprises coating a surface of a connector with nylon and connecting the interdigitated links with the coated connector.
• the coating step comprises electrostatically applying a nylon powder to a surface of the connector and then heating the connector (such as for a period greater than about 15 minutes and at a temperature greater than about 400 0 F).
• the coating step may comprise placing an extruded tube over the connector, which is preferably a metal rod.
• Figure 1 is a partially schematic side view of an overall conveyor system
• Figure 2 is a cross-sectional view taken along line 2-2 of Figure 1;
• Figure 3 is a cutaway, partially cross-sectional view of a wear strip associated with the guide rail for engaging a side link of the conveyor chain;
• Figure 4a is a perspective view of an exemplary side link
• Figure 4b is a cross-sectional side view of the side link
• Figure 4c is a cross-sectional side view of a tab for engaging a transverse connector
• Figure 5 is a partially cross-sectional end view of the modular link conveyor system including roller support rails for the upper and lower runs;
• Figure 6 is a top cutaway view showing the side-flexing capability of one embodiment of the disclosed conveyor chain
• Figure 7 is a perspective view showing a connector including a shell or coating made in accordance with one aspect of the invention.
• FIGS. 8-10 are tables illustrating numerically the result of various experiments conducted to demonstrate the potential efficacy of the inventive aspects disclosed. Detailed Description of the Invention
• FIG. 1 and 2 depict an overall conventional arrangement of a conveyor system S including a belt or chain 10.
• the chain 10 includes a conveying surface 11 for engaging and supporting articles.
• the chain 10 comprises or includes modular links including side guide links 12 and intermediate links 13 arranged in spaced apart rows (see Figure 6 and note rows Rj . . . R n ), which thus partially create the conveying surface 11.
• Adjacent rows R 1 , R 2 of links are interconnected by transversely extending connectors 14, which are also referred to in the vernacular as "cross rods,” “hinge pins,” etc.
• each may include an outer depending arm 12a and an inwardly projecting or extending transverse tab 12b (thus creating different right handed or left handed side links, depending on the particular positioning).
• the depending arm 12a and transverse tab 12b are designed to receive a conventional support structure, which may include a longitudinally extending guide rail G j or G 2 forming part of the conveyor support frame.
• These guide rails G 1 , G 2 support the chain 10 along both the forward run F and the return run R as it is bidirectionally driven in an endless path (such as by spaced sprockets K adapted for engaging the links along a transition from a forward run F to a return run R and gang-driven by an associated motor M).
• Each guide rail G 1 or G 2 preferably includes a wear strip W formed of a tribologically enhanced material to provide reduced friction contact with the links 12.
• the guide rails G 1 or G 2 may be C-shaped or sigma shaped, as shown in Figures 2 and 5, or instead may simply include one or more support sections of any desired shape carrying the associated wear strips W such that they proj ect outwardly therefrom like a tongue or tenon and thus define a bearing surface for the chain 10 (and, in particular, the side guide links 12).
• Associated links of the sort mentioned are typically formed of complementary or matched materials, such as acetal or other inexpensive, lightweight, and durable materials using well-known forming techniques (including possibly co-molding of different materials) .
• pairs of side links 12 together with intermediate links 13 form rows spaced apart in the direction in which the chain 10 is typically driven (referred to as the longitudinal direction or the conveying direction (note action arrow C in the plan view of Figure 6)), since it corresponds to the main direction in which articles are conveyed by the chain 10 during normal operation, as opposed to the transverse or lateral direction P).
• the transverse connector 14 takes the form of a stainless steel rod passing through aligned holes (see Figure 6) formed in foot portions 13c of each intermediate link 13 (which maybe more than two in cases where each link has plural laterally repeating sections), including the side link 12.
• the links 12, 13 of a second, adjacent (trailing) row R 2 interdigitate with those of the first row R 1 , with the connector 14 passing through a slot 12d elongated in the conveying direction D and formed in the apex 12e of each link 12, 13 in the second row (and thereby forming a section of the chain 10).
• this specific structural arrangement (which is considered entirely optional for purposes of the present invention in its broadest aspects) allows for the chain 10 to side-flex to negotiate curves or bends (see Figure 6), as well as to compress or expand in the longitudinal direction, and thus eliminates the need for a catenary. If such enhanced functionality is not necessary for a particular application, the slots 12e could simply be replaced with plain holes for receiving the connector 14, which would this result in a non-side flexing, non-longitudinally compressible chain.
• the connector 14 may be retained in place by a retainer 16.
• the retainer 16 is in the form of a tab 17 removably inserted in a receiver 12f or slot formed in each side link 12.
• the tab 17 may include a recess 17a for engaging a notched or recessed portion 15 of the connector 14.
• This pattern of assembly may be repeated among the interdigitated links 12, 13 as necessary to form a chain 10 having a particular length in the conveying direction.
• a full description of this type of chain or "belt" as it is sometimes called in the vernacular, is found in the commonly assigned '693 and '757 patents, the disclosures of which are fully incorporated herein by reference.
• one aspect of the present invention is providing the connector 14 for at least one row of links at least partially with an outer coating.
• this connector 14 is preferably formed of a rigid core 14a formed of an electrically conductive material, such as one made of mild or stainless steel (e.g., 303 or 304), and coated to create an outer coating or shell 14b comprised of a durable, wear and abrasion resistant material.
• the shell 14b comprises a polyamide, such as nylon, and more preferably Nylon 11 or Nylon 12.
• Nylon 12 is distributed in powder form under the trademark DURALON 12 by the Thermoclad Company of Erie, Pennsylvania.
• nylon powder is sold under the trademark RILSAN by Arkema, Inc. of Birdsboro, Pennsylvania.
• the powder coating may comprise other durable, abrasion-resistant materials, with a preference for those that are polymer-based, such as polyethylene and epoxy coatings, and those identified in the examples provided herein (such as, for example, the following paints: PROTECH CHEMICAL LTD. Mercury Blue hybrid, SHERWIN WILLIAMS Whitewater polyester, SHERWIN WILLIAMS Antique White hybrid, and SHERWIN WILLIAMS Furniture White polyurethane).
• the outer shell 14b may be formed by coating the core 14a, which may be done by placing (e.g., sliding or extruding) a tube or sleeve formed of nylon material over the outer surface.
• the extruded tube or sleeve is made of nylon and bonded to the core 14a, such as by using an adhesive.
• the coating forming the shell 14b (which may also be considered a film) is most preferably applied to the core 14a by a powder coating process.
• Such process involves using an electrostatic delivery device (e.g., a gun) or fmidized bed to deliver the nylon in powder form to the entire outer surface of the core 14a, and then baking the powder at a relatively high temperature (e.g., greater than 400 0 F) for a certain time period (e.g., greater than 15 minutes).
• This baking cures the powder and forms an outer coating (e.g., the shell 14b).
• this technique results in a durable, seamless coating, and one securely bonded to the surface of the core 14a, without the need to adhesives or the like (and without any appreciable gap in which food particles, debris, or the like may become trapped).
• the resulting coated composite connector 14 for use in conveyor belts provides numerous advantages over those presently available for such use, especially when the core 14a is made of stainless steel.
• the shell 14b prevents the deleterious "black oxide” problem from arising when the core 14a is made from stainless steel, including when used with white-colored links made of Acetal.
• the underlying stainless steel forming the core 14a provides an additional layer of protection against corrosion. This is especially true where a perforation or scratch arises in a non-wearing area of the connector 14. This is because the thickness and resulting elevation of the remaining nylon tends to prevent direct contact from being made with the underlying surface of the stainless steel core 14a.
• the shell 14b is also somewhat compliant, at least as compared to a metal such as stainless steel.
• the shell 14b may act to receive and hold any wear particles that may be generated in an embedded fashion. This capturing helps to prevent wear particles once generated from embedding in any adjacent surface of the link and causing further deleterious wear on the connector 14, as occurs using the conventional arrangement.
• the shell 14b when made of nylon also has low coefficient of friction, especially relative to other polymer materials from which links may be formed (including acetal). Thus, the shell 14b does not in any way compromise the operation or performance of the conveyor belt or chain 10. In fact, aside from eliminating the black oxide problem when used with a stainless steel cores it is believed that the properties of the shell 14b will actually extend the service life of the resulting belt by providing an added layer of protection against the effects of wear.
• coating materials capable of being used to form the shell 14b are generally food grade and approved by the FDA for use with food products.
• providing the coating on the steel core 14a made of such FDA-compatible or food grade materials to form the shell 14b does not in any way impact the ability of the belt to be used in a conveyor for food products.
• the shell 14b is believed to improve cleanability by providing a uniform, low friction surface over which cleaning fluids may freely pass and soft particles (such as debris from food products) do not readily adhere.
• the material associated with the core 14a to form the shell 14b is generally clear or translucent (e.g., cloudy but light transmissive) once cured.
• the coating is generally invisible, and the connector 14 appears to be made entirely from steel. This essentially hides the shell 14b and the existence of the coating from the consumer, and also facilitates retrofitting the coated connector into modular link belts or chains without coated connectors.
• the resulting rod 14 would not only be able to resist the growth of undesirable microbes, fungi, germs or bacteria, but would also help to prevent these undesirable entities from propagating (especially in "hidden” or closed areas where the rod passes through cavities or recesses in the links).
• Suitable types of such agents may be found in U.S. Patent Nos. 6,180,039, 6,039,964, 5,941,369, and 5,586,643, the disclosures of which are incorporated herein by reference.
• titanium dioxide having a small particle size can be incorporated into the powder coating, which when cured and bombarded with UV rays serves to attack both inorganic and organic compounds and turn them into molecules that can be harmlessly washed away using water.
• the system 10 can alternatively be characterized as including a first part, such as the metal connector 14 (preferably formed of stainless steel), with a surface subjected to wear as the result of sliding frictional contact with a second part, such as the link 12 or 13 (preferably made of a polymer material and, most preferably, acetal).
• a polymer powder coating or shell such as one made of a polyamide (e.g., nylon) may be applied to the surface of the connector 14 to reduce friction with the link 12 or 13, provide enhanced wear resistance to the connector 14, and improve its cleanability.
• an outer surface of the connector 14 including the powder coating frictionally engages a surface of the link 12, 13 within the opening, including during relative movement between the two (such as when both the connector and link are moving relative to each other, or when the connector moves while the link remains fixed or vice versa).
• Thermoclad was applied to an elongated, generally cylindrical four millimeter diameter rod made of stainless steel (303) using an electrostatic gun.
• the rod with the powder coating was then baked in an oven at a curing temperature of about 400-425 0 F 5 for about 15-20 minutes.
• the resulting composite connector had a durable, seamless shell having a thickness of about 0.003 to 0.005 inches. This added thickness would not contribute significantly to the diameter and thus could be used with existing links or in a retrofit situation.
• Paint Test In order to assess the potential to powder coat stainless steel, a variety of different powder coat paints were tried. These included the following paint types:
• rods were mounted in a holder, immersed in a sand/water slurry bath, and the assembly rotated continuously. This results in rapid wear of the rods. As described below, a total of three different tests have been conducted.
• the second test was a direct comparison of the Nylon 12 coating and the bare stainless steel. A total of approximately eight hours of testing resulted in the stainless steel rods and the Nylon 12 coated rods showing essentially identical wear rates. Figure 9 shows a summary of the total wear on each of the six rods that were tested.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Belt Conveyors (AREA)
• Chain Conveyers (AREA)

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• 2006
  • 2006-09-05 DK DK06814111.8T patent/DK1928766T3/da active
  • 2006-09-05 EP EP06814111.8A patent/EP1928766B1/en active Active
  • 2006-09-05 MX MX2008002464A patent/MX2008002464A/es active IP Right Grant
  • 2006-09-05 CA CA2618856A patent/CA2618856C/en active Active
  • 2006-09-05 US US11/515,542 patent/US7837029B2/en active Active
  • 2006-09-05 WO PCT/US2006/034377 patent/WO2007028102A2/en not_active Ceased
  • 2006-09-05 JP JP2008529349A patent/JP2009506962A/ja active Pending
• 2010
  • 2010-11-22 US US12/951,333 patent/US8522962B2/en not_active Expired - Fee Related

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