WO2007076532A2

WO2007076532A2 - Composite conveyor with serrated intermediate links

Info

Publication number: WO2007076532A2
Application number: PCT/US2006/062700
Authority: WO
Inventors: Lewis W. Ward
Original assignee: Span Tech Llc
Priority date: 2005-12-29
Filing date: 2006-12-29
Publication date: 2007-07-05
Also published as: WO2007076532A3

Abstract

In one aspect, the present invention relates to a conveyor chain (10) with plastic side links (14) and intermediate, wear-resistant metal links (50), both of which are elongated in a direction transverse (T) to the conveying direction (L) In another, the invention relates to a conveyor chain (10) with serrated (54) intermediate links (50) to form a high- friction conveying surface for conveying slick articles In both aspects, the chain is adapted for side-flexing and longitudinal compression

Description

COMPOSITE CONVEYOR WITH SERRATED INTERMEDIATE LTNKS

TMs application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/754,885, filed December 29, 2005.

Technical Field

The present invention relates generally to the conveyor art and, more particularly, to a modular link conveyor for possible use in efficiently and effectively conveying inherently slick articles, such as frozen fish or chicken.

Background of the Invention

Conveyor systems are an integral part of modern production facilities. Such systems are especially beneficial in the food processing and article packaging industries, where it is often desirable to move articles to and from different areas of the production facility to undergo various manufacturing or packaging operations. For example, many food manufacturers require transportation of frozen items from a processing area to a position for final packaging. In terms of processing, many food items, such as raw fish or poultry, are cut directly on the conveying surface, such as by using high- pressure fluid jets.

Conveyor chains with rows of laterally repeating modular links that create a substantially closed conveying surface are perhaps the most popular on the market today. While reliable article support is provided, such a closed surface does not provide the high friction necessary to grip and convey certain articles, including those that are heavy, frozen or that otherwise have relatively slick contact surfaces. Moreover, in the case where high pressure fluid (water) cutting jets are used during processing, the closed surface can be continuously exposed to extreme wear, especially when formed of plastic or polymer materials, which is undesirable for obvious reasons.

Tn an attempt to remedy this problem, others have proposed "open" chain conveyors with laterally repeating, spaced metal links associated with supporting connector rods. An example is shown in Figure 1. Although the conveying surface is indeed wide open, wear-resistant, and can in most instances provide reliable product support, engagement with the articles would be significantly improved by using links providing a conveying surface better able to grip and convey the articles. The use of metal side links in combination with the center links also unnecessarily increases the overall weight of the chain, since the cutting is normally performed along the portion of the conveying surface intermediate of the side links.

Additionally, many production facilities also have limited floor space- thereby making efficient use of the space available imperative. Thus, manufacturers are increasingly desirous of conveyor systems occupying as small an area as possible. To do so, the conveyor chain must have the capability to move product smoothly around curves, as well as along extended runs. The conveyor chain in Figure 1 clearly lacks this capability.

Accordingly, a need is identified for a conveyor chain with a substantially open conveying surface capable of providing full and reliable support for any articles being conveyed, including those that are frozen or otherwise have slick surfaces that might slide freely on a conventional smooth- top chain as it moves along the conveying path, yet with minimal damage to the surface. The conveyor chain would preferably have a substantially open conveying surface defined mostly by links of a strong, wear-resistant material, such as metal, but would use lighter- weight materials where possible to reduce considerably the overall weight of the chain. The chain also be capable of negotiating turns or bends, and thus would allow for a possible savings in the amount of floor space occupied in the production facility. Overall, a substanti al improvement in terms of efficiency and operator satisfaction would result, especially when used in conveying fish, poultry or the like.

Summary of the Invention

Tn accordance with one aspect of the invention, a composite conveyor is provided for conveying articles in a conveying direction. The conveyor comprises a conveyor chain including first and second spaced apart non-metal modular side links interconnected by at least a first connector elongated in a direction transverse to the conveying direction. An intermediate metal link elongated in the transverse direction is supported by the first connector, and includes a conveying surface characterized by serrations spaced in the transverse direction for engaging the underside surface of the articles being conveyed.

In one embodiment, the intermediate link is wavy, and may further include first aligned openings for receiving the first connector. Preferably, the first aligned openings are elongated in the conveying direction. A second connector may also be provided for interconnecting the first and second links, wherein the intermediate link is also supported by the second connector, such as through a second set of openings for receiving the second connector.

In accordance with a second aspect of the invention, a conveyor with a conveying surface for engaging an underside of articles andmoving the articles in a conveying direction is provided. The conveyor comprises a conveyor chain comprised of first and second spaced apart side links interconnected by at least a first connector. A sawtooth intermediate link is supported by the first connector and elongated in a direction transverse to the conveying direction. The intermediate link also includes a sawtooth conveying surface, which may be formed by V-shaped notches defining teeth, for engaging the underside surface of the articles being conveyed.

In one embodiment, the intermediate link includes first aligned openings for receiving the first connector. Preferably, the first aligned openings comprise slots extending generally in the conveying direction. A second connector may also be provided for interconnecting the first and second links. The intermediate link may also be supported by the second connector, and preferably includes a second set of aligned openings for receiving the second connector. Most preferably, the intermediate link is made from a single piece of metal.

In accordance with another aspect of the invention, a side-flexing, compressible composite conveyor is intended for conveying articles in a conveying direction, including along curves. The conveyor comprises a conveyor chain comprised of first and second spaced apart plastic side links interconnected by a first connector. The connector passes through first slots in the links generally elongated in the conveying direction. An intermediate metal link supported by the first connector is elongated in a direction transverse to the conveying direction. The intermediate link includes at least one second slot for receiving the connector passing through the first slots in the links. In one embodiment, the intermediate link has an upper surface characterized by serrations spaced in the transverse direction. In another embodiment, the intermediate link has a sawtooth configuration, and may be made of metal (with the first and second side links preferably made of a non- metal material, such as a polymer). The side links may include at least one depending arm for guiding the chain. The intermediate link is preferably made of a single piece of metal.

In accordance with still another aspect of the invention, a method of conveying articles for processing is provided. The method comprises providing a conveyor chain comprised of first and second spaced apart side links interconnected by first and second connectors, each associated with an intermediate link elongated in a direction transverse to the conveying direction. The intermediate link includes a conveying surface for the articles characterized by the presence of transversely spaced serrations.

In one embodiment, further including the step of applying fluid jets to the articles being conveyed by the chain. In another embodiment, the side links include depending arms with transversely projecting guide tabs, and the method includes the step of suspending the chain along the return run by engaging the guide tabs with a support structure.

Brief Description of the Drawings

Figure 1 illustrates a prior art metal conveyor chain with an open conveying surface;

Figure 2 is a perspective view of a conveyor chain forming one aspect of the invention;

Figure 3 is a top view of a link forming part of the conveyor chain of Figure 2;

Figure 4 is a side view of the link of Figure 3;

Figures 5, 5a, and 5b are perspective and different side cross-sectional views, respectively, of a portion of the link of Figure 3; and

Figure 6 is a perspective view of the intermediate link forming part of the conveyor chain of Figure 2.

Detailed Description of the Invention

Reference is now made to Figure 2, which illustrates one embodiment of the composite conveyor chain 10 of the present invention. The chain 10 includes a plurality of interconnected, non-metal (plastic or polymer) modular links 14 arranged in rows (note three shown, R₁, R₂, and R₃). The links 14 are spaced apart in both the conveying direction (see action arrow L) and a direction transverse to the conveying direction (action arrow T), and thus extend along and define the outermost lateral, sides of the chain 10. Each pair of laterally spaced links 14 is associated with at least two elongated, transversely extending connectors l la, l ib spaced apart in the conveying direction L. The basic structure of the links 14 shown in Figure 2 along with a description of the various types of polymer materials used to form them is set forth in U.S. Pat. Nos. 4,953,693 and 5,031,757, the disclosures of which are incorporated herein by reference.

Referring now to Figure 3 to more fully describe the side links 14 used in the embodiment of the chain 10 shown in Figure 2, each includes a plurality of laterally repeating sections, each having an apex portion 16. A pair of leg portions 18 extend or project from each apex portion 16, preferably in an outwardly diverging relationship. Consequently, a single laterally repeating section of the link 14 in this embodiment is substantially V-shaped in plan view, which of course means that a pair of the sections are substantially W- shaped. As should be appreciated, each link 14 is generally elongated in the transverse direction T, with the upper surfaces of the apex portion 16 and leg portions 18 adapted for engaging and supporting articles for conveyance.

Each leg portion 18 is also associated with a foot portion 20. The foot portion 20 is typically barrel shaped, and may include an upper surface defining a surface capable of engaging and conveying articles. JLn the usual arrangement, and although a chain 10 formed of links 14 of this type is fully reversible, the apex portions 16 define the leading end of the link 14 and the foot portions 20 define the trailing end. In other words, the chain 10 is normally driven along an endless path in the direction of action arrow L in Figure 2, but can be driven in the other direction as well.

Referring now to Figures 4, 5, 5a, and 5b, each apex portion 16 provided in the link 14 includes a first opening or aperture elongated in the conveying direction L. Preferably, this opening comprises a slot 28. Furthermore, the foot portion 20 of each leg portion 18 includes a second opening or aperture, such as a hole 30. The holes 30 of adjacent foot portions 20 are thus coaxial, as are the slots 28 when multiple apex portions 16 are provided (as is the case in Figures 2-5).

As is shown in Figure 2, when two links 14 spaced in the conveying direction L along each side of the chain 10 are interdigitated, the first connector 11a passes through the slot 28 in each apex portion 16 and the hole 30 in each foot portion 20. Consequently, the links 14 in adjacent rows R₁, R₂ are interconnected with each other in such a relationship. As discussed further below, the longitudinal freedom of the connector 11 a in the slot 28 is desirable, since it allows relative movement among the rows R₁, R₂ of links 14 to take place and permits the chain to side flex as well as to expand and compress.

To hold the first connector 1 Ia in this position, it is retained in the outer side portion of each side link 14. In one embodiment, as shown in Figures 5, 5a, and 5b, this is accomplished by providing the outermost foot portion, or side portion 24, of each link 14 with a depending arm portion 32 having a hole 35 co-axial with the hole 30 of each foot portion 20. The hole 35 receives the first connector 11a, and an integral locking tab 36 is inserted within a slot 38 formed in the link 14. As shown in Figures 5a and 5b, the locking tab 36 may include prongs 39 to engage a corresponding circumferential notch 40 provided at each end of the first connector l la. In the preferred embodiment, the locking tab 36 is fabricated from a resilient or flexible material, such as nylon. This construction allows the prongs 39 of the tab 36 to snap lock in the notch 40 for secure engagement and further allows the locking tab 36 to be easily installed and removed.

The locking tab 36 also includes an offset release button 42 seated in an open-ended portion of the slot 38. The button 42 of locking tab 36 assists in the installation and removal of the locking tab 36 from the side portion 24 when, for example, maintenance and repair is required. More specifically, a blade tool, such as a screwdriver, is tapped against the button to initiate prying action. Once sufficient movement is initiated, the screwdriver then provides increased leverage to facilitate removal of the tab 36. The inherent resiliency of the tab 36 allows the prongs 39 to disengage from the notch 40. To reinsert the tab 36, the prongs 39 are directed into the slot 38. It can be appreciated that the resiliency of the tab 36 allows the prongs 39 to snap around the notch 40. Thus, secure retention of the connector l la results. To assist in guiding the chain 10, and with reference again to Figures 5, 5a, and 5b, each UnIc 14 may further include a projecting guide tab 34 associated with each depending arm 32. The guide tab 34 captures the link 14 on the adjacent guide structure (such as a guide rail, not shown) and helps to prevent undesirable tenting. The tab 34 also assists in supporting the chain 10 in a suspended fashion when inverted along a return run forming part of the endless path. As shown in Figure 5, the engagement surfaces of both the depending arm 32 and tab 34 may be tapered to reduce the incidence of binding.

In accordance with one aspect of the invention, and with combined reference to Figures 2 and 6, the chain 10 includes a plurality of intermediate links 50, each for positioning between the spaced apart side links 14 in each row R₁ . . . R_n of the chain 10. Each intermediate link 50 is preferably a unitary or one-piece structure formed of a relatively thin, vertically oriented plate-like, rigid material, such as metal. The link 50 is preferably elongated in the transverse direction T and arranged so as to have a "wavy" or sawtooth shape in plan view, Thus, each link 50 includes a plurality of laterally repeating apexes 52, and is generally symmetrical about a vertical plane aligned with the conveying direction.

The upper surface of each intermediate link 50 is designed to create a high- friction conveying surface for gripping the articles being conveyed, but without cutting the articles or causing unnecessary surface damage. Preferably, this high-friction or gripping surface is created by serrations spaced in the transverse direction (that is, the V-shaped notches forming the serrations are spaced apart laterally) along the top edge of each link 50, including at each apex 52. This creates multiple raised contact points, or "teeth" 54 for engaging the articles being conveyed, thus giving the link a sawtooth. upper (conveying) surface that ensures that the conveying function is provided in a reliable, non- slip manner.

The teeth 54 forming the conveying surface are preferably not tapered in the vertical direction (as they would be in the case of a knife edge), and thus define generally flat surfaces between the points of contact for engaging the underside of the articles being conveyed without deleteriously slicing into the articles to any significant degree. The upper ends of the teeth are also preferably slightly rounded so as to provide the desired point of contact with the article, but again without causing undesirable or unacceptable damage.

Support for the intermediate links 50 results from pairs of the adjacent connectors 11a, l ib interconnecting the spaced side links 14. More specifically, each apex 52 of the link 50 includes either an opening elongated in the conveying direction, such as a slot 56, or an aperture 58. Furthermore, all of the slots 56 and apertures 58 are substantially aligned with each other and with the corresponding slots 28 and apertures 30 in the side links 14. Consequently, the intermediate links 50 are capable of nesting or interdigitating, as well as spreading apart from each other to varying degrees. Thus, the links 50 do not in any way hinder the ability of the chain 10 negotiate curves or bends, or to longitudinally compress in the conveying direction L, which advantageously eliminates the need for a catenary.

In use, an article, such as a piece of raw fish or poultry, may be positioned on the portion of the conveying surface defined by the intermediate links 50 in a desired orientation. The teeth 54 thus make contact with the underside of the article to ensure that it is reliably conveyed in the desired orientation without slippage, and without damaging or cutting the article. The open nature of the conveying surface formed, combined with the use of metal to form the intermediate links 50, also facilitates the use of fluid jets under high pressure to cut the article, without creating excessive splashing or wear on the conveying surface. Besides providing reliable guidance, the plastic side links 14 also help to reduce the overall weight of the chain 10. Also, as detailed in the commonly-owned patents mentioned above, the side links 14 are easy to clean and maintain in a sanitary condition, as is necessary and desired in most food-processing operations.

The intermediate links 50 are most preferably formed of stainless steel to provide good corrosion resistance. The links 50 may be fabricated by cutting and/or drilling the desired openings and serrations in the single piece of material. The material may then be bent to give it the wavy or sawtooth shape and align the openings for receiving the connectors 1 Ia, 1 Ib.

In summary, the present invention provides in one aspect a conveyor chain with non-metal side guide links and intermediate, wear-resistant metal links adapted for conveying inherently slick articles. This arrangement advantageously provides for lower friction conveying by the guide links while retaining the desired wear resistance of the intermediate links, such as for use in fluid jet cutting applications. In another aspect, the invention relates to a conveyor chain with serrated intermediate links to form a high-friction conveying surface for conveying slick articles, such as frozen fish or poultry. In either aspect, the chain may be adapted for side-flexing and longitudinal compression.

The foregoing descriptions of various embodiments of the invention are provided for purposes of illustration, and are not intended to be exhaustive or limiting. Modifications or variations are also possible in light of the above teachings. For example, while one-piece side links are shown, it should be appreciated that these links could be made of two or more links. Likewise, the links 14 may include only a single apex with legs interconnecting foot portions, as described in detail in the '693 patent. The embodiments described above were chosen to provide the best application to thereby enable one of ordinary skill in the art to utilize the disclosed inventions in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention.

Claims

In the Claims

1. A composite conveyor for conveying articles in a conveying direction, comprising: a conveyor chain including first and second spaced apart non- metal modular side links interconnected by at least a first connector elongated in a direction transverse to the conveying direction; and an intermediate metal link elongated in the transverse direction and supported by the first connector, s aid intermediate link having a conveying surface characterized by serrations spaced in the transverse direction for engaging the underside surface of the articles being conveyed.

2. The conveyor according to claim 1 , wherein the intermediate link is wavy.

3. The conveyor of claim 1 , wherein the intermediate link includes first aligned openings for receiving the first connector.

4. The conveyor of claim 3, wherein the first aligned openings are elongated in the conveying direction.

5. The conveyor of claim 1, further including a second connector for interconnecting the first and second links, wherein the second connector supports the intermediate link.

6. The conveyor of claim 5, wherein the intermediate link includes a second set of aligned openings for receiving the second connector.

7. A conveyor with a conveying surface for engaging an underside of articles and moving the articles in a conveying direction, comprising: a conveyor chain comprised of first and second spaced apart side links interconnected by at least a first connector; and a sawtooth-shaped intermediate link supported by the first connector and elongated in a direction transverse to the conveying direction, said intermediate link having a sawtooth conveying surface for engaging the underside surface of the articles being conveyed.

8. The conveyor of claim 7, wherein the intermediate link includes first aligned openings for receiving the first connector.

9. The conveyor of claim 8, wherein the first aligned openings comprise slots extending generally in the conveying direction.

10. The conveyor of claim 7, further including a second connector for interconnecting the first and second links, wherein the intermediate link is supported by the second connector.

11. The conveyor of claim 10, wherein the intermediate link includes a second set of aligned openings for receiving the second connector.

12. The conveyor of claim 7, wherein the intermediate link is made of a single piece of metal.

13. A side- flexing, compressible composite conveyor intended for conveying articles in a conveying direction, including along curves, comprising: a conveyor chain comprised of first and second spaced apart plastic side links interconnected by a first connector, said connector passing through first slots in the links generally elongated in the conveying direction; and an intermediate metal link supported by the first connector and elongated in a direction transverse to the conveying direction, said intermediate link including at least one second slot for receiving the connector passing through the first slots in the links.

14. The conveyor of claim 13, wherein the intermediate link has a upper surface characterized by serrations spaced in the transverse direction.

15. The conveyor of claim 13, wherein the intermediate link has a sawtooth configuration.

16. The conveyor of claim 13 , wherein the intermediate link is made of metal.

17. The conveyor of claim 13, wherein the side links are made of a polymer.

18. The conveyor of claim 13, wherein the side links include at least one depending arm for guiding the chain.

19. The conveyor of claim 13 , wherein the intermediate link is made of a single piece of metal.

20. A method of conveying articles for processing, comprising: providing a conveyor chain comprised of first and second spaced apart side links interconnected by first and second connectors, each associated with an intermediate link elongated in a direction transverse to the conveying direction, said intermediate link including a conveying surface for the articles characterized by the presence of transversely spaced serrations.

21. The method of claim 20, further including the step of applying fluid jets to the articles being conveyed by the chain.

22. The method of claim 20, wherein the side links include depending arms with transversely projecting guide tabs, and the method includes the step of suspending the chain along the return run by engaging the guide tabs with a support structure.