MXPA05004306A - Sprockets in a cleanable modular belt conveyor - Google Patents

Abstract

An easy-to-clean conveyor with sprockets that reveal the hinge area of a modular conveyor belt to a fluid spray. A conveyor includes a modular belt constructed of rows of belt modules hingedly linked together in series by hinge pins into an endless belt loop. A sprocket, mounted on a shaft for rotation, engages an inner surface of the belt in driving or driven contact. The sprocket extends from a central bored hub to an outer periphery, which is arranged to engage the inner surface of the belt along an area of contact that varies laterally across the inner surface of the belt in each rotation of the sprocket.

Description

WHEELS DENTED ON A CLEAN MODULAR CONVEYOR BELT FIELD OF THE INVENTION The invention relates in general to electrically powered conveyor belts and more particularly to modular conveyor belts which are articulated on a gear wheel having an outer periphery that does not rest on a single plane perpendicular to the axis of rotation of the wheel toothed BACKGROUND OF THE INVENTION The belts of modular conveyor belts constructed from rows of plastic belt modules connected in hinged joints by hinge shafts are frequently used to transport meat, poultry and other agricultural products. To comply with the requirements of the United States Department of Agriculture (USDA) and other sanitary requirements, the belts in these applications must be cleaned continuously. The hinged connection between consecutive rows of belt modules is one of the most difficult areas to clean. The corners and grooves in the hinges house bacteria that are not exposed to the spray by cleaning water. Moreover, the teeth of the sprockets that drive the conveyor belt compact the grease, blood and other debris in the hinge. To the extent that the belt is articulated on the sprockets in their transition from the path of travel to the return path, the hinges open to provide larger openings between the inner surface of the belt circuit and the outer surface. For this reason, water sprinklers are often directed to the bottom of the hinge in the vicinity of the sprockets. Unfortunately, conventional sprockets conceal the parts of the hinges along the contact lines of the sprockets with the inner surface of the belt. This problem has been addressed, for example, by the Kwik-Klean Belt Washer sold by Water Management Resources of O 'Fallon, Illinois, United States. In that device, a modular conveyor belt passes over and around at least one toothed wheel located on a non-rotating hollow shaft. The movement of the belt causes the rotation of the sprocket. The gear wheel includes a first pair of diametrically opposed sectors and a second pair of diametrically opposed sectors that are staggered laterally in relation to the first pair of sectors. Each sprocket is flanked by a pair of nozzles, each of which produces a spray in the form of a fan. The fan-shaped sprinklers overlap each other across the lateral extension of the belt, so as to clean the overall width of the belt. The stepped sector design of the sprockets ensures that all sections of the belt are exposed to spray. The nozzles are positioned to clean the belt hinges when they are open. But as a result of the hollow shaft being fixed, it can not operate as a drive shaft. Therefore, a conveyor belt is needed whose hinges can be completely cleaned on the drive sprockets as well as on the freewheels.

SUMMARY OF THE INVENTION This need, as well as others, is satisfied by a conveyor belt having characteristics of the invention. A version of such a conveyor belt consists of a modular belt constructed of rows of belt modules joined in series by hinge shafts on the hinges to form an endless belt circuit. The belt circuit has an outer transport surface and an internal surface facing between lateral edges spaced laterally. A shaft is aligned along an axis within the belt circuit. A gear wheel mounted on the shaft can rotate on the shaft. The gear includes a bushing that forms an internal diameter to receive the shaft. An outer periphery of the sprocket includes drive surfaces spaced circumferentially. An intermediate part of the gear wheel connects the outer periphery to the hub. The outer periphery is arranged to be in contact with the inner surface of the belt along a contact area that varies laterally across the inner surface of the belt at each rotation of the sprocket. In another aspect of the invention, a conveyor belt consists of a similar modular belt and a shaft defining an axis of rotation laterally aligned within the belt circuit. A gear wheel mounted on the shaft can rotate with the shaft on the axis of rotation. The cogwheel extends from a central hub that forms an internal diameter to receive the shaft to an outer periphery. The drive surfaces are spaced circumferentially over the periphery, which is arranged to make contact with the inner surface of the belt along a contact area that varies laterally across the inner surface of the belt at each rotation of the cogwheel.

In another version, a conveyor belt consists of a modular belt constructed of rows of belt modules hingedly connected in series by articulation shafts to form an endless belt circuit having a transport surface and an inner surface facing between edges laterally spaced laterally. A tree is aligned along an axis within the belt circuit. A cogwheel is mounted on the shaft for rotation on the shaft. The sprocket extends from a central hub that forms an internal diameter to receive the shaft at an outer periphery that comes into contact with the inner surface of the belt. At least a part of the external periphery of the gear defines a plane oblique to the axis. In another aspect of the invention, a sprocket that can be mounted on a shaft to rotate about an axis to engage a conveyor belt consists of a hub and an outer periphery connected by an intermediate portion. The bushing forms an internal diameter to receive a shaft that defines an axis. The outer periphery is to make contact with the inner surface of the belt circuit. At least a part of the outer periphery defines a plane oblique to the axis. According to another aspect, a toothed wheel that can be mounted on a shaft for rotation with the shaft on an axis of rotation for coupling the inner surface of a belt conveyor belt circuit consists of a bushing and an outer periphery connected by a intermediate part. The bushing forms an internal diameter to receive a shaft that defines an axis of rotation. The drive surfaces for contacting the inner surface of a conveyor belt are circumferentially spaced on the outer periphery, which is arranged to contact the inner surface of the belt along a contact area that varies laterally to the belt. Through the internal surface of the belt at each rotation of the gear.

BRIEF DESCRIPTION OF THE FIGURES These and other features, aspects and advantages of the invention are better understood by reference to the following description, claims and appended figures, wherein: Figure 1 is a pictorial view of an end of a conveyor belt incorporating characteristics of the invention; Figure 2A is a pictorial view of a version of a gear wheel usable on a conveyor belt of Figure 1, with two adjacent sections separable on a tree. Figure 2B is a side elevational view of one of the sections, and Figure 2C is a side elevational view of the other of the sections; Figure 3A is a pictorial view of another version of a sprocket used in the conveyor belt of Figure 1, with an oblique flat periphery, and Figure 3B is a front elevational view of the gear of Figure 3A; Figure 4A is a pictorial view of yet another version of a sprocket usable in the conveyor belt of Figure 1 with a pair of oblique sectors forming the periphery, and Figure 4B is a front elevation view of the sprocket of Figure 4A; and Figures 5A, 5B and 5C illustrate the contact area of the sprockets of Figures 2, 3 and 4 with the inner surface of a belt circuit.

DETAILED DESCRIPTION OF THE INVENTION A part of a conveyor belt including features of the invention is illustrated in Figure 1. The conveyor belt 10 includes a modular plastic conveyor belt 12 that is articulated on a pair of sprockets 13. The belt it is constructed from a series of rows of belt modules 15. Each row includes one or more belt modules and, if there are multiple modules per row, the belt is preferably arranged in a masonry pattern. Hinge rings are interspersed at the ends of the facing rows of the belt modules. The aligned rings form a lateral passage path between each row. An articulation shaft 16 is fitted in each passage path to connect the rows of modules in a worm loop circuit. The belt circuit extends in thickness from an external transport surface 18 to an inner surface 19. The plastic modules that make up the belt are typically injection md from a thermoplastic material, such as, for example, polypropylene, polyethylene and acetal. The sprockets are illustrated in Figure 1 mounted on a shaft 20 aligned laterally within the belt circuit at one end of a portion of the transport path of a typical transport path. However, the sprockets could be mounted in different locations along the belt path in other applications. The shaft defines an axis 22 on which the sprockets rotate. The illustrated tree is a square tree with round ends 24 supported on pedestals 27 at each end. The shaft can be either an intermediate shaft or a drive shaft. In this example, the shaft is a drive shaft driven by a motor 28 in a direction of travel of the belt 30. As the belt is articulated on the gears in its transition from the upper transport path to the return path lower, the hinges open between the rows of belts. A fluid spraying system 32 directs fluid within the hinges in the sprockets. The fluid spray system illustrated in this example includes a laterally disposed spout 34 with outlets 36 formed along its length. A pressurized source of fluid 38 is connected to one end of the pipe through a valve 40 and a hose 41. The outlets may be nozzles or slits in the pipe and may be arranged to supply a selected spray pattern to clean the best form the strap. The details of a sprocket 14 usable in the conveyor belt of Figure 1 are illustrated in Figures 2A-C. Each sprocket consists of two half sprockets 42-43. Each half cog has a central hub 44 with an internal diameter 45 therethrough. The illustrated inner diameter has four right angle corners 46 to accommodate a square shaft 20. The recesses 48 between the corners provide access for cleaning the internal diameter and the shaft. Each half sprocket extends outwardly from the hub through an intermediate portion 50 to an outer periphery 52. In this version, the outer periphery can be described, in a first approximation, as parts of a circular arc 53. The motor structure , including trailing motor cavities 56 on the periphery causes the periphery to deviate from a perfectly circular arc. Accordingly, the term "arc" is used for convenience in this context to define the part, or angular extent, of the periphery of a part in the form of sector of a cogwheel. However, if the wheel were non-motive and did not have to positively track a belt, the outer periphery could be smooth and define an exactly circular arc. Each of the halves of the gear of Figures 2B and 2C defines a pair of coplanar peripheral arcs circumferentially offset from each other by 180 °. Each arc covers a sector of exactly more than 90 °. When both halves of the sprocket are mounted adjacent to one another on the shaft 20, the peripheral arcs of one move 90 ° with respect to the peripheral arcs of the other. Since the two halves of the sprocket are separate pieces, they are also displaced from one another by the width of the hub. Although the toothed wheel of Figure 2 consists of two halves, it could be realized as a gear wheel of three thirds, four quarters and so on, with the corresponding peripheral arcs and angular compensations. In an axial view, the periphery looks continuous with a slight overlap at the ends of each arc. The windows 58 in the middle part of the sprocket halves make the sprocket lighter and easier to clean. But the middle part of the sprocket and the other sprockets described could be solid, without windows. Unlike a conventional flat gear, the periphery of the gear wheel of Figure 2A compensation makes contact with the inner surface of a conveyor belt along a contact area that varies laterally across the inner surface of the belt at each rotation of the sprocket. Figure 5A illustrates the pattern of the contact area of the gear of Figure 2A at the bottom of the belt. The compensation pattern is repeated every half rotation of the gear. The lateral displacement means that the parts of the inner surface of the belt are not hidden by the sprocket through the complete transition of the belt, from the transport path to the return path. In this way, the fluid sprayer can clean the belt more effectively by accessing the full width of the belt as it travels around the sprockets. The gear 13 illustrated on the conveyor belt of Figure 1 is illustrated in greater detail in Figures 3A and 3B. The sprocket extends from a central hub 64 to an outer periphery 66. An intermediate part 68, in the form of spokes separated through the window 70, connects the hub to the outer periphery. The motor structure on the outer periphery includes driving cavities 72 and driving teeth 74. The driving cavities receive complementary driving faces on the internal surface of the belt. A driving force is transmitted from the cavities to the drive faces on the belt when the sprocket is mounted on a drive shaft. When the sprocket is mounted on an intermediate shaft, the driving force is transmitted from the drive faces of the belt to the cavities in the sprocket. The hub also defines an internal diameter 76 for receiving the shaft and cleaning grooves 78 along the walls. As illustrated in Figure 3B, the periphery of the shaft generally rests on a plane 80 that is oblique to the axis 82 of the internal diameter 76. Since the axis of the periphery is oblique to the axial direction (the lateral direction of the belt), the driving surfaces are oblique to the lateral edges 84 of the periphery, in such a way that they adequately couple the complementary structure on the internal surface of the belt. Like the compensating sprocket of Figure 2, the angled sprocket of Figure 3 engages the belt along a contact area that varies laterally across the inner surface of the belt during each rotation of the wheel toothed The pattern is illustrated in Figure 5B. Unlike the pattern (Figure 5A) of the compensation sprocket, the resulting triangular wave pattern is continuous and repeated during each rotation. Another version of the sprocket usable on a conveyor belt, such as that of Figure 1, is illustrated in Figures 4A and 4B. In this version, the gear 86 is illustrated without the drive structure at its periphery 88. But the periphery could include the drive structure as that of the other versions or of any other configuration. The gear includes a bushing 90 with a central internal diameter 92. The bushing is connected to the periphery through the intermediate structure in the form of spokes 94 separated by windows 96. The periphery consists of two sections 88 A 88", each defines circular circumferential areas of approximately 180 °. Each section is generally supported on oblique intersecting planes 98 ', 98", which are also oblique to the axial direction 99 of the internal diameter and, consequently, the lateral dimension of the belt. The ends of each peripheral arc are connected to the ends of the other by connection parts 100. The contact area of the divided helical periphery of the gear of Figures 4A and 4B defines a sawtooth pattern along the inner surface of the belt, as illustrated in Figure 5C. The pattern is repeated in each half rotation of the cogwheel. Since the periphery of the sprocket moves laterally, the sprocket reveals the total width of the internal surface of the belt for washing. Although the invention has been described in detail with respect to a few versions, other versions are possible. For example, the drive structure in any of the sprockets may include drive teeth or drive cavities, or the periphery could be smooth or polygonal. The separable toothed sprockets of Figure 2 can be formed unitarily on a single bushing. Moreover, different numbers of sectors, or extensions of peripheral arcs, can be used in the compensation sprockets with similar effects. As another example, the bushings could define circular or multilateral internal diameters, instead of the square internal diameter illustrated. Instead of rotating with trees, the sprockets could be mounted on circular bearings arranged to rotate on fixed circular trees. Therefore, as the examples suggest, the claims are not intended to be limited to the versions described in detail.

Claims (39)

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, the content of the following is claimed as a priority: CLAIMS

1. A conveyor belt, CHARACTERIZED BECAUSE: a modular belt constructed of rows of belt modules connected in a hinged manner in series by means of articulation shafts to form an endless belt circuit having an external transport surface and an internal surface facing between the edges laterals spaced laterally; a tree aligned along an axis within the belt circuit; a wheel mounted on the shaft for rotation about the shaft where the sprocket includes: a bushing that forms an internal diameter to receive the shaft; an outer periphery forming motor surfaces spaced circumferentially; an intermediate part that connects the outer periphery to the hub; wherein the outer periphery is arranged to be in contact with the inner surface of the belt along a contact area that varies laterally across the inner surface of the belt at each rotation of the sprocket.

2. A conveyor belt, according to the definition of claim 1, characterized in that the outer periphery of the gear generally defines a circle that rests on a plane oblique to the axis.

3. A conveyor belt, according to the definition of claim 1, characterized in that the outer periphery of the gear defines a first arc that rests on a first plane oblique to the axis, and a second arc that rests on a second Oblique plane to the foreground.

4. A conveyor belt, as defined in claim 3, CHARACTERIZED BECAUSE the outer periphery of the sprocket further includes a connecting part connecting the first and second arc.

5. A conveyor belt, as defined in claim 1, CHARACTERIZED BECAUSE the outer periphery of the gear generally defines a first arc and a second arc axially and circumferentially offset from one another.

6. A conveyor belt, as defined in claim 5, CHARACTERIZED BECAUSE the outer periphery of the sprocket further defines a third arc circumferentially compensated for the first arc.

7. A conveyor belt, as defined in claim 5, characterized in that the outer periphery of the gear defines a third arc coplanar with and circumferentially compensated for the first arc and a fourth arc coplanar with and circumferentially compensated from the second arc. .

8. A conveyor belt, according to the definition of claim 1, characterized in that the gear wheel consists of two separate parts,

9. A conveyor belt, according to the definition of claim 1, characterized in that it also consists of a sprinkler by fluid positioned adjacent to the shaft and arranged to direct a fluid spray on the inner surface of the belt.

10. A conveyor belt, according to that defined in claim 1, CHARACTERIZED BECAUSE the shaft is a drive shaft for driving the belt.

11. A conveyor belt, CHARACTERIZED BECAUSE: a modular belt constructed of rows of belt modules connected in a hinged manner in series by articulation shafts to form an endless belt circuit having an outer transport surface and an internal surface facing between lateral edges laterally spaced; a shaft aligned laterally within the belt circuit and defining an axis of rotation; a gear wheel on the shaft for rotation with the shaft on the axis of rotation, wherein the gear extends from a bushing forming an internal diameter to receive the shaft to an outer periphery forming circumferentially spaced motor surfaces; wherein the outer periphery is arranged to come into contact with the inner surface of the belt along a contact area that varies laterally across the inner surface of the belt at each rotation of the sprocket.

12. A conveyor belt, as defined in claim 11, CHARACTERIZED BECAUSE the outer periphery of the sprocket generally defines a circle that rests on a plane oblique to the axis of rotation.

13. A conveyor belt, according to the definition of claim 11, characterized in that the outer periphery of the gear defines a first arc that rests on a first plane oblique to the axis of rotation and a second arc that rests on a oblique second plane to the foreground.

14. A conveyor belt, according to that defined in claim 13, CHARACTERIZED BECAUSE the outer periphery of the sprocket further includes a connecting part connecting the first and second arc.

15. A conveyor belt, as defined in claim 11, CHARACTERIZED BECAUSE the outer periphery of the gear generally defines a first arc and a second arc axially and circumferally offset from one another.

16. A conveyor belt, as defined in claim 15, CHARACTERIZED BECAUSE the outer periphery of the sprocket further defines a third arc circumferally compensated for the first arc.

17. A conveyor belt, as defined in claim 15, CHARACTERIZED BECAUSE the outer periphery of the gear defines a third arc coplanar with and circumferally compensated from the first arc and a fourth arc coplanar with and circumferally compensated from the second arc. arc.

18. A conveyor belt, according to that defined in claim 11, CHARACTERIZED BECAUSE the gear wheel consists of two separate parts.

19. A conveyor belt, as defined in claim 11, CHARACTERIZED BECAUSE it comprises a fluid sprayer positioned adjacthe shaft and arranged to direct a fluid spray on the inner surface of the belt.

20. A conveyor belt, as defined in claim 11, CHARACTERIZED BECAUSE the shaft is a drive shaft for driving the belt.

21. A conveyor belt, CHARACTERIZED BECAUSE: a modular belt constructed of rows of belt modules joined in series hinged by hinge shafts to form an endless belt circuit having an outer transport surface and an inner surface facing each other lateral edges spaced laterally; a shaft aligned along an axis within the belt circuit; a sprocket mounted on the shaft for rotation about the shaft, wherein the sprocket extends from a bushing forming an internal diameter to receive the shaft to an outer periphery that comes into contact with the inner surface of the belt; wherein at least a part of the outer periphery defines a plane oblique to that axis.

22. A conveyor belt, as defined in claim 21, CHARACTERIZED BECAUSE the entire outer periphery is generally coplanar.

23. A conveyor belt, as defined in claim 21, CHARACTERIZED BECAUSE another part of the outer periphery rests in another plane oblique to the axis,

24. A conveyor belt, as defined in claim 21, CHARACTERIZED BECAUSE the sprocket also includes teeth spaced around the periphery of the sprocket.

25. A conveyor belt, as defined in claim 21, CHARACTERIZED BECAUSE the sprocket further includes cavities spaced around the periphery of the sprocket.

26. A conveyor belt, as defined in claim 21, CHARACTERIZED BECAUSE it further comprises a fluid sprayer positioned adjacent to the shaft and arranged to direct the spray of fluid on the inner surface of the belt.

27. A cogwheel mountable on a shaft for rotation on an axis and engageable with a conveyor belt loop circuit, CHARACTERIZED BECAUSE it comprises: a bushing forming an internal diameter to receive a shaft defining an axis; an outer periphery for making contact with the inner surface of a belt circuit; an intermediate part that connects the outer periphery to the hub; wherein at least a part of the outer periphery defines a plane oblique to the axis.

28. A gear wheel, as defined in claim 27, CHARACTERIZED BECAUSE the entire outer periphery is generally coplanar.

29. A gear wheel, according to that defined in claim 27, CHARACTERIZED BECAUSE another part of the outer periphery is aligned in another plane oblique to the axis.

30. A gear wheel, as defined in claim 27, CHARACTERIZED BECAUSE the gear wheel also teeth spaced around the periphery of the gear wheel.

31. A sprocket, according to that defined in claim 27, CHARACTERIZED BECAUSE the sprocket further includes cavities spaced around the periphery of the sprocket.

32. A sprocket mountable on a shaft for rotation with the shaft on an axis of rotation and engageable with the inner surface of a conveyor belt loop, the sprocket CHARACTERIZED BECAUSE comprises: a bushing forming an internal diameter for receive a tree that defines an axis of rotation; an outer periphery forming circumferentially spaced motor surfaces contacting the inner surface of a belt; an intermediate part that connects the outer periphery to the hub; wherein the outer periphery is arranged to make contact with the inner surface of the belt along a contact area that varies laterally across the inner surface of the belt at each rotation of the sprocket.

33. A sprocket, according to that defined in claim 32, CHARACTERIZED BECAUSE the outer periphery of the sprocket generally defines a circle that rests on a plane oblique to the axis of rotation.

34. A sprocket, according to that defined in claim 32, CHARACTERIZED BECAUSE the outer periphery of the sprocket defines a first arc that rests on a first plane oblique to the axis of rotation and a second arc that rests on a oblique second plane to the foreground.

35. A sprocket, according to that defined in claim 34, CHARACTERIZED BECAUSE the outer periphery of the sprocket further includes a connecting part connecting the first and second arc.

36. A cogwheel, as defined in claim 32, CHARACTERIZED BECAUSE the outer periphery of the sprocket generally defines a first arc and a second arc axially and circumferentially offset from one another.

37. A gear wheel, according to that defined in claim 36, CHARACTERIZED BECAUSE the outer periphery of the gear defines a third circumferentially compensated arc of the first arc.

38. A gear wheel, as defined in claim 36, CHARACTERIZED BECAUSE the outer periphery of the gear defines a third coplanar arc with and circumferentially compensated from the first arc and a four coplanar arc with and circumferentially compensated from the second arc. arc .

39. A gear wheel, according to that defined in claim 32, CHARACTERIZED BECAUSE the gear wheel consists of two separable parts.