Patent Application
20080023303
The present invention relates to the conveyor art and, more particularly, to a modular link or link section for forming a “rodless” conveyor belt or a section thereof.
Today, in many modern manufacturing facilities, modular conveyor systems are extensively utilized to transport articles to and from various work stations during all stages of production. In recent years, manufacturers using production lines with conveyors as an integral component of the material handling system have realized reasonably significant gains in productivity and resource utilization. As a result, modular conveyor systems have become even more widely implemented and have been adapted to meet an even wider scope of the material handling needs of producers of a multitude of consumer and industrial goods. Therefore, the continual development of improved modular conveyors is necessary in order to keep pace with the demands and expectations of the users of such conveyors.
Conventional conveyor systems employing endless, modular link or roller chain belts are typically driven at one end of an elongated guide structure, such as a rail or the like supported above the ground by a frame. The driving force is transmitted from a motive device, such as a variable speed electric motor, to a plurality of gang-driven sprockets coupled to a rotating drive structure, such as a shaft or drum. At the opposite end of the guide structure, idler sprockets are coupled to a freely-rotating idler shaft or drum. As should be appreciated, the drive and idler sprockets assist in supporting and guiding the endless belt as it makes the transition from the forward run to the return run, or vice versa, at each respective end of the guide structure. Intermediate drive units, including frictional drives, may also be used in place of or in addition to the end drive unit.
Oftentimes, the belts are formed of a plurality of laterally repeating modular links, or unitary link sections comprising a plurality of laterally repeating link-shaped structures (collectively referred to as “links”). The links are typically formed of a low-cost high strength, wear resistant material, such as Acetal or UHMW polypropylene). To form the belt, a plurality of links or link sections are positioned in interdigitating, longitudinally repeating rows. Each row is then connected to the adjacent row by a transverse connecting rod that projects through one or more apertures in a first, usually leading portion of a first link or link section and one or more apertures or slots in a second, or trailing portion of the next-adjacent link or link section. At both lateral ends of each row, special side links are used that include slots for receiving a locking structure, such as a tab, that holds the transverse connector rod in place. Examples of this type of arrangement are found in commonly assigned U.S. Pat. Nos. 4,953,693 and 5,031,757, the disclosures of which are incorporated herein by reference. Due to their low-cost, adaptability and long service life, belts formed in this fashion have gained widespread acceptance among those seeking conveying solutions.
In the past, others have recognized the potential value of a “micropitch” belt formed of a plurality of interconnected links, but capable of behaving almost like it is formed of a continuous piece of material, such as a fabric. An example is found in U.S. Pat. No. 5,967,296 to Dolan. The belt disclosed in the '296 patent includes a plurality of link sections including laterally and longitudinally offset spherical beads having apertures for receiving a plastic transverse connector rod. Once inserted through the aligned apertures in a pair of interdigitated link sections, both ends of the connector rod are mutilated, such as by melting. This captures the rod in place between the link sections to form a belt section.
While the “micropitch” belt disclosed in the '296 patent is indeed capable of behaving more like a continuous piece of material than a conventional modular link conveyor belt, the primary disadvantage of this proposal is that it takes an extraordinary number of man hours to form the belt. The worker must position two tiny link sections adjacent to each other, align them in an interdigitating relationship, and then thread the narrow plastic rod through the aligned apertures. Both ends of the connector rod must then be melted to ensure that it remains held in place. These actions must be repeated hundreds of times to form even a couple feet of belting, which greatly contributes to the manufacturing time, effort, and expense. Also, if even a single transverse rod is not properly installed, it can slide out of position over time and possibly allow for a complete belt failure.
In the past, others have proposed different types of “regular” pitch conveyor chain or belting that eliminates the need for the transverse connector rod. For example, a “rodless” belt in which each link includes opposed integral stub shafts that are loosely received in open box-shaped receivers on the next-adjacent link is shown in U.S. Pat. No. 4,394,901 to Roinestad. A narrow-width example is found in U.S. Pat. No. 3,952,850 to Specht, in which each link includes a receiver that is open from above for receiving an integral rod forming a part of the next-adjacent link in a snap-fit engagement.
While these types of arrangements may generally serve a particular need or purpose, none are readily adaptable for being scaled down to create a “micropitch” belt. For example, the link disclosed in the '901 patent includes many intricate features that would be exceptionally difficult to replicate in a substantially smaller version (e.g., a link that is only 6 millimeters in height). Moreover, in the case of lightweight plastic materials, the strength of structures such as the opposed integral stub shafts projecting from each link may be compromised if made substantially smaller. The narrow-width chain in the '860 patent is arguably more amenable to downsizing. However, the resulting chain would be only a single link wide. With the exception of forming a conveyor with a plurality of these narrow-width chains positioned in a side-by-side fashion and driven at the same speed, this arrangement would thus not be practical for replacing the typical fabric belt or the like.
Accordingly, a need is identified for links or link sections that, among other things, are readily capable of being scaled down to form a “micropitch” belt. Regardless of size, the links would also be capable of being interconnected without the need for separate transverse connecting rods to form a relatively wide “rodless” belt. This would greatly reduce the assembly time, effort and expense without substantially compromising the durability, strength, or service life of the resulting belt. In cases where the links are formed of plastic materials, the use of integral connectors formed of the same materials would also result in a weight savings as compared to the conventional modular link belt including stainless steel transverse connector rods. Providing the belt with a relatively wide conveying surface would facilitate receiving and transporting many different types of articles, including possibly as part of a transfer assembly positioned between the ends of two adjacent conveyors. Driving the belt could also be accomplished using a sprocket or a friction drive, which would enhance the versatility and concomitantly increase the options available to the conveyor system designer. Overall, a “rodless” belt having these capabilities would be a substantial improvement over those known in the art.
In accordance with a first aspect of the invention, a unitary modular link section for intended use in coupling with an adjacent link section to form a part of a conveyor belt for conveying articles or products is disclosed. The link section comprises a plurality of laterally repeating link-shaped portions. Each link-shaped portion includes a surface capable of engaging or assisting in supporting the articles or products being conveyed, a pair of leg portions, at least one first integral connector extending between the leg portions, and a receiver capable of receiving a portion of the adjacent link in snap-fit engagement. The snap-fit engagement allows for the easy and secure assembly of the link section with the adjacent link section to form the part of the conveyor belt.
In one embodiment, the receiver includes an oversized entryway and opposed, inwardly sloping or tapered sidewalls that form a neck. In use, the portion of the adjacent link section passes through the oversized entryway, along the inwardly sloping sidewalls, and snaps past the neck to become captured in the receiver, thereby creating the desired snap-fit engagement. The leg portions of each link-shaped portion may also include an outer sidewall, and a second integral connector may be provided between the outer sidewall of one leg portion of a first link-shaped portion and the adjacent outer sidewall of one leg portion of a second, adjacent link-shaped portion. The second integral connector is adapted for engaging a tooth on a drive or idler sprocket for driving or guiding the belt.
In accordance with a second aspect of the invention, a unitary modular link for intended use in coupling with an adjacent link to form a part or section of a conveyor belt for conveying articles or products is disclosed. The link comprises a plurality of laterally repeating apex portions, each including a surface capable of engaging or assisting in supporting the articles or products being conveyed. A pair of leg portions extend from each apex portion, and at least one integral connector is positioned between the leg portions. Each apex portion includes a receiver capable of receiving a portion of the adjacent link in snap-fit engagement. This allows for the easy and secure assembly of the link with the adjacent link to form the part or section of the conveyor belt.
In one embodiment, the receiver in each apex portion includes an oversized entryway and opposed, inwardly sloping or tapered sidewalls that form a neck. Accordingly, the portion of the adjacent link passes through the oversized entryway, along the sloping sidewalls, and snaps past the neck to become captured in the receiver and create the desired snap-fit engagement. The leg portions of each apex portion may further include an outer sidewall. A second integral connector is provided between the outer sidewall of one leg portion of a first apex portion and the adjacent outer sidewall of one leg portion of a second, adjacent apex portion. The second integral connector is adapted for engaging a tooth on a drive or idler sprocket for driving or guiding the belt.
In a particularly preferred embodiment, each apex portion includes a pair of outer sidewalls, each having a taper in the vertical plane. Moreover, each leg portion includes an inner sidewall having a slope that corresponds to the taper. Hence, when two links constructed in this manner are interconnected, the sidewalls cooperate or match and permit a particular degree of relative pivoting movement.
In accordance with a third aspect of the invention, a unitary modular link; section for intended use in coupling with an adjacent link section to form a part or section of a conveyor belt for conveying articles or products is disclosed. The link section comprises at least two laterally repeating link-shaped portions, each including an upper surface for engaging or assisting in supporting the articles or products. First and second leg portions also form a part of each link-shaped portion, and at least one first integral connector is positioned between the first and second leg portions. A second integral connector is also provided between the first leg portion of a first link-shaped portion and the adjacent, second leg portion of a second link-shaped portion. Each link-shaped portion further includes a receiver capable of receiving and capturing a portion of the next-adjacent link section.
In one embodiment, the first and second integral connectors are substantially cylindrical, with the second integral connector being larger in diameter than the first integral connector. In any case, each first connector is adapted for being received in a receiver of the next adjacent link. Likewise, each second connector is adapted for being engaged by a tooth on a drive or idler sprocket for driving or guiding the belt.
In accordance with a fourth aspect of the invention, a modular link conveyor belt section for intended use in forming a part of an endless conveyor belt for conveying articles or products is disclosed. The belt section comprises a plurality of link sections. Each link section includes a plurality of laterally repeating link-shaped portions, each having a surface for engaging or assisting in supporting the articles or products, a pair of leg portions, and at least one first integral connector. The link-shaped portions of a first one of the link sections each further include a receiver for receiving the first integral connector of a second, adjacent link section in snap-fit engagement, such that the first link section is capable of pivoting movement relative to the second link section. The snap-fit engagement allows for the easy and secure assembly of the link sections to form the conveyor belt section.
In one embodiment, the first integral connector extends between the leg portions of the second link section, and the receiver of each link-shaped portion on the first link section includes an oversized entryway and inwardly sloping sidewalls forming a neck. Hence, each first integral connector of the second link section passes through the oversized entryway, along the sloped sidewalls, and snaps past the neck to become captured in the receiver and form the desired snap-fit engagement. The leg portions of each link-shaped portion on one or both of the first and second link sections may include an outer sidewall and a second integral connector may be provided between the outer sidewall of one leg portion of a first link-shaped portion and the adjacent outer sidewall of the leg portion of a second, adjacent link-shaped portion. The second integral connector provides a surface for engaging a tooth on a drive or idler sprocket for driving or guiding the belt.
In one particular embodiment, each link-shaped portion includes an apex portion having a pair of outer sidewalls, with each sidewall having a taper in the vertical plane. Each leg portion of the second link section includes an inner sidewall having a slope that matches the taper. Consequently, the matching sidewalls facilitate relative pivoting movement to a limited degree between the first and second link sections.
In another embodiment, the underside surfaces of the first and second link sections are specially contoured or curved. Consequently, when these link sections are pivoted a certain, preselected amount, the underside surfaces may correspond to the contour of an adjacent guide structure, such as a cylindrical nosebar. As a result, the belt section is capable of smoothly traversing over the guide structure.
Each link-shaped portion may further include an apex portion having a generally arcuate or rounded nose and a matching recess. When two adjacent link sections are interconnected, the nose of each apex portion on the first link section cooperates with the recess of each apex portion on the second link section during relative pivoting movement. Likewise, each leg portion may include a generally arcuate or rounded leading recess and a matching trailing surface. In use, the trailing surface of each leg portion on the first link section cooperates with the leading recess of each leg portion on the second link section during relative pivoting movement.
In accordance with a fifth aspect of the invention, a modular link conveyor belt section for intended use in forming a part of an endless conveyor belt capable of conveying articles or products and traversing over a guide structure having a relatively small diameter, such as a nose bar, is disclosed. The belt section comprises a plurality of link sections, each including a plurality of laterally repeating link-shaped portions having a surface for engaging or assisting in supporting the articles or products, a pair of leg portions, and an integral connector. The link-shaped portion of a first one of the link sections includes a receiver for receiving the integral connector of a second link section such that the first link section is capable of pivoting relative to the second link section. The underside surfaces of both of the first and second link sections are specially contoured or curved such that when the link sections are pivoted a preselected amount, the underside surfaces may correspond to the contour of the guide structure. As a result, smooth travel of the belt section over the guide structure is facilitated.
In one embodiment, the integral connector extends between the leg portions of the second link section and the receiver of each link-shaped portion on the first link section includes an oversized entryway and opposed, inwardly sloping sidewalls that form a neck. Hence, each integral connector of the second link section passes through the oversized entryway, along the sloping sidewalls, and snaps past the neck to become captured in the receiver and form the snap-fit engagement. The leg portions of each link-shaped portion on one or both of the first and second link sections may include an outer sidewall and a second integral connector may be provided between the outer sidewall of one leg portion of a first link-shaped portion and the adjacent outer sidewall of the leg portion of a second, adjacent link-shaped portion. The second integral connector provides a surface for engaging a tooth on a drive or idler sprocket for driving or guiding the belt.
In one particular embodiment, each n-shaped portion includes an apex portion having a pair of outer sidewalls, with each sidewall having a taper in the vertical plane. Each leg portion of the second link section includes an inner sidewall, with the inner sidewall having a slope that matches the taper. In use, the matching sidewalls facilitate relative pivoting movement to a limited degree between the first and second link sections.
In another embodiment, each link-shaped portion includes an apex portion having a generally arcuate leading nose and a matching recess. When adjacent link sections are interconnected, the nose of each apex portion on the first link section is positioned closely to and moves along the recess of each apex portion on the section link section during relative pivoting movement. Likewise, each leg portion includes a generally arcuate leading recess and a matching trailing surface. In use, the arcuate leading recess of each leg portion on the second link section is positioned closely to and moves along the trailing surface of each leg portion on the first link section during relative pivoting movement.
The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention.
In the drawings:
a is an enlarged, partially cross-sectional side view of two of the links or link sections of
b is an enlarged cross-sectional view showing the two interconnected links or link sections along line 6b-6b of
c is an enlarged side view showing the relative pivoting movement of one link or link section relative to the other when interconnected;
d is an enlarged top plan view showing the two interconnected links or link sections of
With reference to the exploded perspective view of
Turning first to the perspective view of
Two leg portions 22, 24 project or extend from the apex portion 14. The leg portions 22, 24 include a generally planar upper surface 26 that is capable of engaging or assisting in supporting articles being conveyed. Each leg portion 22, 24 further includes an outer sidewall 28, an inner sidewall 30, a leading recessed portion 32 that is generally arcuate, rounded or curved, and a trailing portion 34 that is also generally arcuate, rounded or curved. As will be understood better after reviewing the description that follows, the curvature of the leading recessed portion 32 generally matches the curvature of the trailing portion 34, such that the outer surfaces of these portions cooperate without interference when two of the link sections 10 are interconnected and caused to pivot relative to one another.
Positioned between the inner sidewalls 30 of the leg portions 22, 24 associated with each apex portion 14 is at least one first integral connector 36. In the illustrated embodiment, the first integral connector 36 is a single, continuous, generally cylindrical piece of material that extends between and is integrally formed in the opposed inner sidewalls 30 of each leg portion 22, 24. The first connector 36 is spaced from a recessed portion 38 of the corresponding apex portion 14. This recessed portion 38 is adapted for cooperating with the outer surface of the rounded nose 16 on the apex portion 14 of a next-adjacent link and, thus, is also generally arcuate, rounded or curved (see
In the illustrated embodiment, a second integral connector 40 extends between the outer walls 28 of the adjacent leg portions 22, 24 and, thus, connects the adjacent, substantially identical link-shaped portions 12a, 12b, 12c, 12d to form the unitary link section 10a . . . 10n. The second integral connector 40, like the first one, may also be barrel-shaped or cylindrical, but is preferably oversized as compared to the first connector 36 to ensure that a strong connection is established between the adjacent link-like portions 12a . . . 12n. As will further understood upon reviewing the description that follows, this second connector 40 is the structure designed for engaging a tooth on a drive or idler sprocket used to drive or guide a belt formed of the link sections 10a . . . 10n.
Turning now to
With specific reference now to
Turning now to
In the preferred embodiment, the link sections 10a, 10b are fabricated of lightweight, low-cost wear-resistant plastics materials (Acetal, UHMW polypropylene, etc.). While these materials are generally rigid, the design of the apex portion 14 is such that the nose portion 16 is capable of flexing outwardly relative to the remainder of the link section 10a or 10b. Consequently, each first connector 36 can pass through the neck N with the application of only a moderate amount of force, yet remains securely captured once in place in the receiver 18. It should also now be appreciated that providing the first integral connector 36 with a smaller diameter relative to the second connector 40 may be an important feature, since it may allow for the corresponding receiver 18 to consume less of the material forming the apex portion 14 and may contribute to the overall strength of the link section 10.
As can be appreciated from viewing
As perhaps best shown in
In the illustrated embodiment, the link sections 10a, 10b are capable of pivoting through a range of approximately 85° (from about positive 25° in the first quadrant to about negative 60° in the fourth quadrant (300° when measured from the horizontal or X-axis); note action arrow P in FIG. 6c and the position of phantom link section 10a′). As noted above, increasing or decreasing this range is possible by changing the relative orientation of the matching sidewalls 30, 42. For instance, orienting the sidewalls 30, 42 generally perpendicular to a transverse axis and substantially parallel to each other may allow for a greater degree of pivoting movement. Likewise, changing the taper of one sidewall 30, 42 without making a corresponding change to the other may serve to limit the degree of relative pivoting movement. The ultimate choice depends on the characteristics desired for a particular application. In any case, it should be appreciated that an extreme range of pivoting may at the upper and lower ends result in a “closing up” the space between the second integral connectors 40 for receiving a sprocket tooth (see
As perhaps best shown by viewing
For purposes of illustration, each link section 10 is shown as including a partial integral connector 58 projecting from the outer sidewall 28 of the outermost link-shaped portions 12a, 12d. While this feature is optional, it provides several advantages when present. First of all, it provides a surface for abutting with a guide structure, such as a guide rail, sidewall, or the like. Secondly, it may abut with a corresponding connector 58 projecting from a laterally-adjacent link section (not shown) in situations where shorter link sections are “brick-layered” with longer link sections (not shown) (e.g., two link sections spaced laterally side-by-side, each with four laterally repeating link-shaped portions, coupled to an upstream unitary link section having eight laterally repeating link-shaped portions). In this type of arrangement, the abutting connectors 58 not only cover the void that would otherwise exist between laterally adjacent link sections, but also provide a structure that may be engaged by a corresponding drive or idler sprocket positioned at the center of the longer link section (e.g., between the fourth and filth link-shaped portions, in the case where there are eight total). Thirdly, the connector 58 may be sized and shaped to fit into and slide along a corresponding channel (not shown) formed in a guide structure, such as a sidewall supported by a support structure such as a conveyor frame. This type of arrangement can also be used in assisting in supporting a belt formed of the link sections 10a . . . 10n along the return run of the conveyor, for providing guidance as it passes through an intermediate drive structure or the like, or for other types of arrangements where simultaneously capturing, guiding, and supporting a moving belt is necessary.
In the drawing figures, the link sections 10a . . . 10n are shown as being enlarged. In the most preferred embodiment, each link section 10a, 10b has a height H of approximately 6 millimeters (see
A conveyor belt C formed of the link sections 10a . . . 10n may be supported and guided using any conventional arrangement, including well-known types of support beds, rails, or the like. Instead of stub connectors 58, it is also possible to adapt the ends of the link section 10 to include depending side arms with inwardly projecting guide tabs for engaging a guide rail (not shown), as disclosed in the commonly assigned '757 patent. As should be appreciated, a “regular” sized, non-“micropitch” link is more amenable to having these types of depending and inwardly projecting structures, since weakening due to the smaller dimensions may be less of a concern.
Numerous modifications are possible in light of the foregoing teachings. For example, as briefly noted above, it is possible to orient the sidewalls 30, 42 such that each is generally perpendicular to an imaginary centerline axis extending through the transverse integral connector rods 36, 40. This design may provide the adjacent links with more freedom in terms of relative pivoting movement. Also, while four link-shaped portions 12a-12d are shown for purposes of illustration, it should be appreciated that as few as two may be included. The maximum number of link-shaped portions is limited only by constraints such as the strength of the material used in forming the link sections (which of course may depend on their size or the particular application).
Additionally, the number of second integral connectors 40 provided may also be adjusted as necessary or desired to achieve a particular purpose. For example, in the case where there are four link-shaped portions 12a-12d, it is possible to provide a second integral connector 40 between portions 12a and 12b and between portions 12c and 12d, each for engaging a corresponding drive or idler sprocket. Portions 12b and 12c can simply be merged together at the interface between the outer sidewalls 28 of the corresponding leg portions 22, 24 (not shown). In cases where a belt formed of the link sections 10a . . . 10n is not sprocket-driven, the second integral connectors 40 could be eliminated altogether, with the adjacent leg portions 22, 24 simply being merged together. However, it is preferable to create laterally symmetrical link sections 10a . . . 10n that laterally repeat with the same predictable frequency.
The relative size and width of the apex portion 14 and the leg portions 22, 24 may also be changed as necessary to achieve a particular result. For example, in the case where a slightly stronger link section is required, it may be beneficial to widen the leg portions 22, 24 and shorten the apex portion 14 in the transverse or width dimension. The sizes, shapes, and relative orientations of the receiver 18 and the connectors 36, 40 may also be changed as necessary, such as to strengthen the link section 10 or achieve any other desired result. It should be her appreciated that, in the “regular” pitch version of the link section 10 formed of lightweight plastic materials, the use of integral connectors in place of the conventional stainless steel connector rods may substantially reduce the weight of the resulting belt.
It is also possible to construct an embodiment of the link section 10 in which the first integral connector 36 is positioned between but does not extend completely from one inner sidewall 30 to the other. Instead, the connector may comprise two opposed, spaced stub shafts (not shown, but see partial projection 58) that project inwardly from each sidewall 30. With this embodiment, it should be further appreciated that the receiver 18 may be divided by a wall or partition (not shown) into two receivers, one of which receives each stub shaft comprising the integral connector 36. The wall or partition does serve to strengthen the resulting link section 10, but is generally considered optional. This embodiment is somewhat less preferred, since the opposed stub shafts are considerably weaker than the continuous connector 36, especially in the “micropitch” arrangement.
Also, it is fairly well-known in the art that the use of identical plastic materials in each adjacent link section may result in squeaking. While this does not affect the operational characteristics or performance of a belt or chain formed of these link sections, it can be an annoyance. Therefore, the desirability of forming the adjacent interconnected link sections of two different types of plastics materials is noted. It is believed to be a matter of ordinary or routine skill to select suitable plastic materials or combinations thereof to eliminate squeaking.
The foregoing description of the various embodiments of the link or link section forming one aspect of the invention is presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. For example, the terms “apex” or “legs” are merely used to describe structures of each link section 10, and are not intended to limit the link section to a particular shape, orientation or limit the bidirectional driving capabilities of a belt formed of such link sections. Modifications or variations are also possible in light of the above teachings. For example, a plurality of upwardly projecting fingers may be provided on the conveying surfaces of each link section 10 to enhance the article-engaging capabilities. The embodiments chosen were described to provide the best application to thereby enable one of ordinary skill in the art to utilize the invention 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 as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.
This is a continuation of U.S. patent application Ser. No. 10/505,943, which is the national stage of international application PCT/US03/05666, filed Feb. 26, 2003, the disclosures of which are incorporated herein by reference, which claim the benefit of U.S. Provisional Patent Application Ser. Nos. 60/359,582, 60/423,067, and 60/435,221.
| Number | Date | Country | |
|---|---|---|---|
| 60359582 | Feb 2002 | US | |
| 60423067 | Nov 2002 | US | |
| 60435221 | Dec 2002 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10505943 | Aug 2004 | US |
| Child | 11839284 | Aug 2007 | US |
