WO2006014910A2

WO2006014910A2 - Modular plastic conveyor belt with large open area and self-cleaning at hinges

Info

Publication number: WO2006014910A2
Application number: PCT/US2005/026411
Authority: WO
Inventors: James J. Harrison
Original assignee: Kvp Falcon Plastic Belting, Inc.
Priority date: 2004-07-31
Filing date: 2005-07-26
Publication date: 2006-02-09
Also published as: WO2006014910A3

Abstract

A modular plastic conveyor belt is made up of molded plastic modules connected together by transverse pins and is intended to replace wire belting in bakery, breading, cooling, enrobing and transfer conveyors, for example. The modular belt can be made in nearly in any width, provides for easy repair and greatly reduces conveyor down-time. In one form the belt is about 56% open for maximum drainage, being formed in a grid-like arrangement of relatively thin, integrally molded pieces. 45° angled hinges provide for self-cleaning as the connecting rod or pin rotates, and the hinges are open at both sides to promote belt self-cleaning. The ribs of the modules preferably are T-shaped in cross section to allow a larger bottom open area. Other features help promote self-cleaning of the belt, add stiffness and strength, retain the pins and provide for longer hinge life.

Description

EXPRESS MAIL NO. EV 604784322 US

684/PCT

APPLICATION FOR UNITED STATES PATENT

MODULAR PLASTIC CONVEYOR BELT WITH LARGE OPEN AREA AND SELF-CLEANING AT HINGES

S P E C I F I C A T I O N

Background of the Invention

This invention concerns conveyor belts, and is concerned in particular with modular plastic conveyor belts assembled from a series of molded plastic modules serially connected by transverse connecting rods, with a very high percentage of open area. In particular the belts can replace wire mesh belting which has been used in bakeries and other applications. The invention is concerned with self-cleaning and clean ability features in such module plastic conveyor belts.

Conveyor belts used in various operations in bakeries have typically comprised wire mesh belting, with large open area. More and more in the past several decades, modular plastic belting has replaced wire belting in a number of industries, including bakeries. However, most modular plastic belting has not had the open belt area desired in many baking operations, usually needed for adequate convection and air flow in several baking operations, as well as for drainage. One plastic conveyor belt intended for the service described above has been sold by Intralox Inc., division of Laitram Corporation of Harahan, Louisiana, this belt is sold under the name "1500 Flush Grid Belt" commencing in approximately 2001. The belt was characterized as having a 48% open area for drainage. The belt was of one-half inch pitch, was characterized as being capable of nosebar transfers of one-half inch, and had partially open hinged structures. The ends of the modules, i.e. the left and right edges of the belt, had interlocking structure outboard of the end of the connecting rod, for engaging each module together with the preceding and succeeding modules in this edge region for belt cohesion and increased stiffness and strength.

Although partially effective for its intended purpose, the Intralox 1500 series belt did not have as much open area as the belt of the present invention described below, nor did it have the degree of open hinge construction of the invention, nor the self-cleaning features at the hinge which are incorporated in the invention.

Summary of the Invention

A modular plastic conveyor belt of the invention is made up of molded plastic modules connected together by transverse rods, the belt being an efficient replacement for wire belting in bakery breading, cooling, enrobing and transfer conveyors, for example. The modular belt can be made in nearly in any width, provides for easy repair and greatly reduces conveyor down time.

In one form the belt is about 53% open for maximum drainage, being formed in a grid-like arrangement of relatively thin, integrally molded pieces. 45°-angled ribs have holes supporting the rod or pin at hinges providing for self-cleaning as the connecting rod rotates, and the hinges are open at sides to promote belt self-cleaning. The angled ribs of the modules preferably are T-shaped in cross section to allow a larger bottom open area. Other features help promote self-cleaning of the belt, add stiffness and strength, retain the pins and provide for longer hinge life.

It is accordingly among the objects of the invention to provide an improved and effective alternative to wire mesh belting in bakery breading, cooling, enrobing and transfer conveyors, as well as other applications requiring a large open area in a belt, as well as to reduce conveyor down time, provide for quick repairs, and provide for self-cleaning of the belt and for an easy clean ability. These and other objects, advantages and features of the invention will be apparent from the following description of preferred embodiments, considered along with the drawings.

Description of the Drawings

Figure 1 is a plan view showing a plastic belt module according to the first embodiment of the invention. Figure 2 is a plan view showing a section of conveyor belt with the modules as in Figure 1.

Figure 3 is a perspective view showing a module such as in Figure 1.

Figure 3A is an end view of the module shown in Figure 1. Figure 4 is a perspective view the section of belt of Figure 2 made up of the modules of Figures 1 and 3.

Figure 5 is a top plan view showing a section of belt assembled from modules similar to those of Figures 1-4 but with different edge configuration. Figure 6 is a bottom plan view showing of the belt of Figure 5.

Figure 7 is an upper perspective view showing a belt module as in Figure 5.

Figure 8 is an end elevation view of a module which is not connected to a succeeding module.

Figure 9 is a transverse cross-sectional view in elevation, along a pin, showing pin retention in the assembled belt.

Figure 11 is an upper perspective view showing a portion of a belt assembly as in Figures 5-9.

Description of Preferred Embodiments

In the drawings, Figure 1 shows a plastic conveyor belt module which is configured generally in a zig-zag shape, or undulating shape across its width. The module pin is integrally molded of a suitable plastic material such as acetal, nylon, polyethylene, polypropylene, or amended materials such as glass filled plastics or metal detectable or other materials suitable for use particularly in the food industry, with good strength and capable of withstanding relatively high and low temperatures.

The module 10 has a first series of projections 12 extending one direction of motion of the belt, and a second series of preferably similar projections 14 extending in the opposite direction. End projections are shown at 16, at both left and right edges of the module, these edge projections aligning with the second series of projections 14. The module 10 is shown assembled with a series of other modules forming a section of belt 18 in Figure 2, the modules being assembled with their projections interdigited and secured together with connecting rods or pins 20. The module and belt section are also shown in perspective in Figures 3 and 4.

The belt of the invention has a very large open surface area, approximately 53% in the embodiment as shown in Figures 1 and 2. In addition, the pins that extend through apertures at 22 (Figures 3 and 4) in the projections are mostly exposed at fore and aft side's, since the apertures formed by the projections 12 and 14 are mostly open at the fore and aft sides. Each projection 12 or 14 is formed of an essentially cut-away barrel portion or cylindrical portion 24 and a pair of obliquely angled ribs 26, 28, that integrally connect the cut-away cylinders of the projections of the both the first and second series, as best seen in Figures 1 and 3.

The essentially cut-away cylinders 24 include an axial aperture for the pin, and each has an upper and lower pin- parallel elongated plate 30, 32 at top and bottom, as seen in Figures 1-4. The two parallel plates are connected together at left and right ends, but preferably only on one side, by the side facing toward the next module in the series of modules, as seen at 34 in Figures 1, 3 and 4. The pin, in fact, is almost nowhere fully surrounded by module structure. The pin is surrounded in an oblique plane at each point where an obliquely angled rib 26, 28 intersects with a barrel or cylinder member 24 in this preferred embodiment. Virtually along the entire length of the rod or pin, where module structure engages against the pin on one of the fore/aft sides, the directly opposite side of the pin is exposed. This is important in promoting self-cleaning of the pin during operation of the conveyor belt. The mostly open fore and aft sides are readily cleaned by air, water or other fluid. In addition, the pin tends to rotate during service, partially because of the angled ribs 26, 28 and the apertures which obliquely envelop the pin at these positions, and this rotation along with some vibration of the belt tends to self- clean the pin. Also, the pin "floats" and tends to migrate back and forth (left-right) in the assembled belt during movement of the belt, and this further promotes self-cleaning. The module 10 may be similar at top and bottom as regards the essentially cut-away cylinders or barrel members 34, but the ribs 26 and 28 preferably are narrower at bottom than at top. They may be essentially T-shaped in cross-section and in addition, the ribs may arch upwardly as they extend between the front and back of the belt, as can be seen in Figure 4 and Figure 3A, which is an end view of the belt module. The arch 36 is clearly seen from this view. As a result, the bottom is even more open than the top, allowing for better particle release and aiding clean ability.

As seen in Figure 2, the assembled belt section 18 has a very high percentage of open area. The belt in one application acts as a replacement for wire belting in bakery, breading, cooling, enrobing and transfer conveyors. The degree of open area is higher than that of previous modular plastic belts.

Pin retention in this embodiment is by rod heading. Rod or pin heads 20a are shown at one side of the belt, positioned between two prongs 16a and 16b of the edge projection 16 at one of the left and right sides of the belt, as seen in Figure 2. These rod heads 20a can be formed, with a reasonable degree of precision, before the rods or pins 20 are inserted into the belt, and then forced through the aperture of the outer prongs 16a of the edge projection 16 in the last about 1/4 inch of travel of the pin into the belt. The pin head must be large enough to ensure the rod cannot back out or move forward in the other direction through the belt, but small enough to allow its being forced through the aperture. This can be accomplished with a heated punch and die.

Although the modules and belt sections specifically shown in Figures 1-4 comprise a series of full-width modules making up the width of the assembled conveyor belt, it should be understood that multiple modules can be used to make up the width of the belt, allowing belts to be assembled in nearly any width. Accordingly, modules can be provided with the illustrated edge configuration at only one edge (left or right) , with the other end of such a module terminating at the middle of one of the barrel or cylinder members 24.

Alternatively, the termination point could be through one of the obliquely angled rib members 26, 28. Intermediate modules will have such termination points at both ends. Such a collection of modules can be manufactured in different widths such that the modules in a wide belt can be staggered or

"bricklaid" as to position in the belt, so that joints between adjacent side-by-side modules are not continuous through the length of the belt.

Figures 5-11 show a modified module and assembled belt wherein the modules are essentially the same as already described, but with different edge configuration.

Figure 5 shows several of the modified modules 40 attached together, revealing a section of belt in top plan view. Figure 6 shows a section of belt in bottom plan view. The modules have a modified edge configuration 42 by which pin insertion and pin retention are accomplished in a different way. In this case an extension or T-bar 44 extends in a longitudinal direction (of the belt) at the edge of each module row, an integral formation of the module 40. This T- bar has a rounded-top transverse portion 44a as seen particularly in Figures 7, 8 and 11. This portion 44a nests into a recess or pocket in the edge of an adjacent module, as can be seen in Figures 5, 6 and 9-11. The bottom view of Figure 6 shows the T bars 44 attached into the recesses 46 of adjacent modules. The shapes of the T-bar portion 44a and the mating socket are such as to permit relative rotation of the adjacent modules as the belt travels around a sprocket or guide roller. As is seen in Figures 9 and 10, the T-bar end portion 44a in the assembled belt is positioned to block part of the pin apertures 48, and these T-bar members 44a function in the assembled belt to prevent outward migration of the pin. However, in the module 40 prior to assembly, as shown in Figure 8, the T-bar is undeflected and does not obscure the pin apertures. Assembly of the belt is accomplished by positioning adjacent, successive modules such that their projections 12, 14 are interdigited, as in Figures 1 and 2. Then, while the T-bar 44 is pulled downwardly relative to the top surface of the belt (upwardly if belt is inverted) , far enough to clear the path defined by the pin apertures, a pin is inserted through the apertures of the interdigited projections, until it clears the position of the T-bar 44. This can be envisioned from Figure 9, if the T-bar transverse end 44a is pushed downwardly past the aperture space. The T-bar is then allowed to spring back toward its normal position, but is prevented by the structure of the adjacent module from fully reaching its normal position (see Figures 5, 9 and 10) . Figure 9 shows that a top or roof section 42a of the module edge configuration 42 holds the T-bar end 44a down. This captures the pin in place. This slight deflection of the T- bars in the assembled belt puts no noticeable stress on the belt and securely retains all pins in place without need for "heading" the ends of the pins.

The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to this preferred embodiment will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims.

I CLAIM:

Claims

684 /PCT

1. A modular plastic conveyor belt with a large open area, having a top and a bottom and of the type made up of a series of connected elongated molded plastic belt module rows each including one or more belt modules in the row such that belts of varying selected widths can be made up from the modules in a staggered pattern, with the belt module rows connected by pins extending transversely to the length of the conveyor belt, each row having a series of first spaced projections generally regularly spaced and extending in one direction from the row and a series of second spaced projections generally regularly spaced and extending in an opposite direction from the row, the first and second projections of serially adjacent module rows being longitudinally overlapping and juxtaposed when the modules are connected serially in the conveyor belt by the connecting pins extending through transverse openings in the projections, comprising: each module being of a zig zag configuration, with first and second projections comprising first intermittently positioned sections generally parallel to a pin and generally engaging around the pin and forming the first projections, and second intermittently positioned sections generally parallel to and generally engaging around a succeeding pin which is parallel to and spaced apart by a pitch distance from the first pin, the second sections being staggered in position in relation to the first sections, and the first and second sections being connected by integrally formed, obliquely angled ribs to form the zig zag configuration, and wherein the first and second sections are mostly open in exposing the pins for cleaning.

2. The conveyor belt of claim 1, wherein each of the first and second sections comprises spaced apart parallel top and bottom pieces, with the pin being completely surrounded essentially only at locations where the angled ribs connect to each section.

3. The conveyor belt of claim 1, wherein each pin is exposed through about 70% of its length on a front side of the pin, facing a fore direction of the assembled belt, and about 70% on a back side of the pin, facing an aft direction of the assembled conveyor belt.

4. The conveyor belt of claim 1, wherein a pin is fully encircled by a module only along obliquely angled lines of the ribs so that at substantially all locations on a front or fore side of the pin that are engaged by belt module structure, a directly opposite aft side of the rod is open and exposed.

5. The conveyor belt of claim 1, wherein the belt surface has approximately 53% open area.

6. The conveyor belt of claim 1, wherein the belt has open surface area greater than 50%.

7. The conveyor belt of claim 6, wherein the ribs are generally T-shaped in cross section, having greater width at the top of the belt than at the bottom of the belt.

8. The conveyor belt of claim 7, the T-shaped cross section of the ribs comprising a depending stem and a crossing top, and the stem's length making a slight angle with respect to the length of the crossing top such that the stem and top extend at different oblique angles relative to a vertical plane transverse to the path of travel of the belt, thus adding stiffness to the ribs.

9. The conveyor belt of claim 1, wherein the ribs are generally T-shaped in cross section, having greater width at the top of the belt than at the bottom of the belt.

10. The conveyor belt of claim 9, the T-shaped cross section of the ribs comprising a depending stem and a crossing top, and the stem's length making a slight angle with respect to the length of the crossing top such that the stem and top extend at different oblique angles relative to a vertical plane transverse to the path of travel of the belt, thus adding stiffness to the ribs.

11. The conveyor belt of claim 1, wherein the ribs are angled at approximately 45° to the rod.

12. The conveyor belt of claim 1, wherein the pins are positioned in the assembled conveyor belt so as to permit both rotation and lateral sliding movement of the pin to encourage self-cleaning of the pin.

13. The conveyor belt of claim 1, wherein each of the first and second sections comprises essentially a cylinder, elongated in the transverse direction of the belt, with a pin- receiving aperture through length of the cylinder, with portions of the cylinder removed at fore and aft sides of the cylinder relative to the direction of movement of the belt, said portions removed to expose the pin along the majority of the length of the cylinder at both fore and aft sides of the cylinder.

14. The conveyor belt of claim 13, wherein the section or cylinder is open, exposing the pin, in about 60% of the length of the cylinder at each of the fore and aft sides.

15. The conveyor belt of claim 13, wherein the cylinder or section is open, exposing the pin, at least in about 50% of the length of the cylinder or section at both fore and aft sides.

16. The conveyor belt of claim 15, wherein the ribs are T-shaped in cross section, greater in width at the top of the belt than at the bottom of the belt.

17. The conveyor belt of claim 1, wherein pin-receiving apertures are defined in each module at aligned series of intersections of the obliquely angled ribs with the first and second sections of the projections, such that fully pin- encircling apertures are formed essentially only at said intersections, by the obliquely angled ribs.

18. The conveyor belt of claim 17, wherein each of the first and second sections comprises essentially a pair of pin- parallel elongated plates at top and bottom of the section.

19. The conveyor belt of claim 18, wherein the parallel plates are connected at left and right ends, at only one of the fore and aft sides, in addition to being connected at the intersections with the obliquely angled ribs.

20. The conveyor belt of claim 1, wherein each of the first and second sections comprises essentially a pair of pin- parallel elongated plates at top and bottom of the section.

21. The conveyor belt of claim 20, where the parallel plates are connected at left and right ends, at only one of the fore and aft sides, in addition to being connected at the intersections with the obliquely angled ribs.

22. The conveyor belt of claim 1, including, at an end of each module row, a module edge configuration including a T- bar with a stem and a transverse end, the transverse end having a length oriented transversely to the path of travel of the conveyor belt and having a normal undeflected position just above or below the path of a pin to extend through said transverse openings in the projections, and the module edge configuration further including a T-bar receiving recess directly forward or aft of the T-bar and open at one of its top and bottom sides for receiving a T-bar of a succeeding module, the module edge configuration of one module in the assembled belt engaging the transverse end of the T-bar of an adjacent module and holding the T-bar in a deflected position such that the transverse end of the T-bar is blocking the path of a pin through said transverse openings to capture the pin in the assembled belt, whereby for removal of a pin from connecting succeeding module rows, the T-bar can be pushed toward its open side to further deflect the T-bar until the transverse end clears the path of the pin, allowing the pin to be slid out from the belt.

23. An open mesh plastic modular conveyor belt configured generally similarly to wire belting, the conveyor belt being made up of a series of interdigited plastic modules with connecting pins extending transversely through the belt, through apertures defined by the modules in fore projections and aft projections of each module, the fore projections of one module being interdigited with the aft projections of an adjacent module with a pin passing through such interdigited projections, the belt having a very large open surface area and comprising: the projections being formed as a first series of aligned and intermittently positioned essentially cut away cylinders with aligned axial apertures to retain a first pin and a similar second series of intermittently positioned essentially cut away cylinders, in a line parallel to and spaced away from the first series of cut away cylinders and in staggered relationship with the positions of the first series of cut away cylinders, with aligned apertures in the second series to retain a second pin which is parallel to the first pin and spaced therefrom by a pitch distance of the belt, and obliquely angled ribs connecting the first and second series of cut away cylinders, forming a zig zag or generally undulating configuration of each module, and each essentially cut away cylinder comprising upper and lower elongated, spaced apart plates forming upper and lower sides if the aperture and integrally connected to the obliquely angled ribs, with fore and aft sides of the cut away cylinder mostly open so as to expose the pins.

24. The modular conveyor belt of claim 23, wherein the pin in the aperture of the projection is fully surrounded by the projection essentially only at intersections of the angled ribs and the upper and lower plates of the essentially cut away cylinder.

25. The conveyor belt of claim 24, including, at an end of each module row, a module edge configuration including a T- bar with a stem and a transverse end, the transverse end having a length oriented transversely to the path of travel of the conveyor belt and having a normal undeflected position just above or below the path of a pin to extend through said apertures of the projections, and the module edge configuration further including a T-bar receiving recess directly forward or aft of the T-bar and open at one of its top and bottom sides for receiving a T-bar of a succeeding module, the module edge configuration of one module in the assembled belt engaging the transverse end of the T-bar of an adjacent module and holding the T-bar in a deflected position such that the transverse end of the T-bar is blocking the path of a pin through said apertures of the projections to capture the pin in the assembled belt, whereby for removal of a pin from connecting succeeding module rows, the T-bar can be pushed toward its open side to further deflect the T-bar until the transverse end clears the path of the pin, allowing the pin to be slid out from the belt.

26. A plastic modular conveyor belt made up of a series of interdigited plastic modules in succeeding module rows with connecting pins extending transversely through the belt, through apertures defined by the modules in fore projections and aft projections of each module, the fore projections of one module being interdigited with the aft projections of an adjacent module with a pin passing through such interdigited projections, the belt having a pin retention arrangement for preventing a pin from escaping transversely out of the belt, comprising: at an end of each module row, a module edge configuration including a T-bar, with a stem and a transverse end, the transverse end having a length oriented transversely to the path of travel of the conveyor belt and having a normal, undeflected position just above or below the path of a pin to extend through one set of said apertures in the projections, and the module edge configuration further including a T-bar receiving recess directly forward or aft of the T-bar, in line with another set of said apertures in the projections, opposite said one set, and open at one of its top and bottom sides, for receiving a T-bar of a succeeding module, the module edge configuration of one module in the assembled belt engaging the transverse end of the T-bar and holding the T-bar of an adjacent module in a deflected position such that the transverse end of the T-bar is blocking the path of a pin through said apertures of the projections to capture the pin in the assembled belt, whereby for removal or insertion of a pin to connect succeeding module rows, the T-bar can be pushed toward the open side of the recess to further deflect the T- bar until the transverse end clears the path of the pin, allowing the pin to be slid out from the belt or into the belt.

27. The conveyor belt of claim 26, wherein the module edge configuration comprises an end projection with an extension transverse to the direction of travel of the belt and providing an outermost aperture for a pin, the T-bar receiving recess being just inboard of the outermost aperture, and the stem of the T-bar being flexible and extending from said extension in the direction of said one. set of apertures to position the T-bar's transverse end adjacent to said one set of apertures so that the T-bar can engage with a succeeding module.