Multi-piece sprocket

Abstract

A multi-piece sprocket for a conveyor belt or chain includes a first part and a second part that mates with the first part to form a sprocket having drive teeth distributed around the periphery and a central hub for holding a shaft. The second part is inserted into a space within the first part and rotated to an engaged position, whereby the curved hooks enter the curved channels of the first part to form a complete sprocket. A locking mechanism can secure the two parts together.

Description

[Technical Field]

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 450,147, entitled "Multi-Piece Sprocket," filed March 6, 2023, the contents of which are incorporated herein by reference. [Background technology]

[0002] FIELD OF THE INVENTION The present invention relates generally to sprockets and other conveyor components that can be assembled to shafts in endless conveyor belt systems.

[0003] Sprockets are used to drive endless transmission and conveyor belts and chains. Each sprocket is mounted on a shaft that is received by a hole extending axially through the sprocket. The shaft is supported at both ends by bearing blocks attached to the conveyor frame. A gearbox or belt drive pulley attached to the end of the shaft makes the shaft a drive shaft. Installing a one-piece sprocket onto a drive shaft requires removing at least one bearing block and sliding the sprocket axially onto the shaft. Typically, the shaft must also be lifted from the conveyor side frame. Other components that may be mounted on the shaft within a conveyor include, but are not limited to, rollers, position limiters, belt guards, belt supports, and other known components.

[0004] Split sprockets, which are split along seams in the bore, can be installed on a shaft without removing the bearing block. The first piece of the split sprocket is positioned on the shaft. A complementary second piece is then mated with the first piece. The two pieces are typically secured together by a pair of bolts or screws. One form of split sprocket used with conveyor belts has two identical halves that fit together in an interlocking puzzle-piece configuration. Screws passing through the puzzle-piece configuration at both seams fasten the pieces together. However, the two screws do not provide much resistance to axial movement of one sprocket half relative to the other. Additionally, the need for tools to assemble the sprocket complicates assembly and disassembly and can also present cleanliness issues, potentially limiting sanitation. Summary of the Invention

[0005] One form of multi-piece sprocket embodying features of the present invention includes first and second sprocket components that mate to form a sprocket with drive teeth distributed around its periphery. A central hub of the sprocket carries a shaft. The first component includes an open peripheral portion and an open hub connected to the open peripheral portion. The second component forms a cap for closing the peripheral portion and the open hub. The second component is inserted into a space formed by the first component in a first orientation and rotated to a second orientation to mate with the first component to form a complete sprocket.

[0006] According to one embodiment, a sprocket for a conveyor belt includes a first component having a passageway and a second component inserted into the passageway. The first component has a curved peripheral portion defining a drive element, a hub radially inward of the peripheral portion for receiving a shaft, a passageway extending along a radial axis from a space within the curved peripheral portion to the hub, and first curved channels extending through the first sprocket component from a first face to a second face. The first curved channels are curved about the radial axis. A second sprocket component completes the peripheral portion and the hub and includes first curved projections configured to be received in the curved channels when the second sprocket component is rotated about the radial axis from a first orientation in which the second sprocket component is inserted into the passageway to a mating position in which the second sprocket component completes the peripheral portion and the hub.

[0007] According to another aspect, a sprocket for a conveyor belt includes a curved peripheral portion defining a drive element, a hub radially inward of the peripheral portion for receiving a shaft, a passageway extending along a radial axis from a space within the curved peripheral portion to the hub, first curved channels on a peripheral surface of the peripheral portion forming a curved molding projection between the passageway and the first curved channels, and second curved channels adjacent the hub, intersecting the passageway and extending through the first sprocket component from the first face to the second face. The second sprocket component is inserted into the passageway to complete the peripheral portion and the hub. The second sprocket component includes hooks at a peripheral end configured to be received in the first curved channels and curved tabs at an inner end configured to be received in the second curved channels. The second sprocket component is rotated about the radial axis from a first orientation in which the second sprocket component is inserted into the passageway to a mating position in which the peripheral portion and the hub are completed.

[0008] According to another aspect, a sprocket assembly for a conveyor belt includes a shaft and a split sprocket attached to the shaft. The shaft includes an opening in an outer surface. The split sprocket includes a first sprocket component including an open hub for receiving the shaft, a locating nub in a wall of the open hub configured to engage the opening in the shaft, a peripheral portion, a passageway along a radial axis between the hub and the peripheral portion, and at least one curved channel extending from a first surface to a second surface. The second sprocket component includes at least one curved protrusion configured to be received in the curved channel. The second sprocket component is rotated about the radial axis from a first orientation in which the second sprocket component is inserted into the passageway to a mating position in which the peripheral portion and the hub are completed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a front view of an assembled multi-piece sprocket according to one embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the multi-piece sprocket of FIG. 1 mounted on a shaft. [Figure 3] FIG. 3 is an exploded view of the multi-piece sprocket and shaft of FIG. 2. [Figure 4] 4 is a perspective view of a cap portion of the multi-piece sprocket of FIG. 1. FIG. [Figure 5] FIG. 5 shows the multi-piece sprocket of FIG. 2 as it is being assembled onto a shaft. [Figure 6] FIG. 6 shows a defining portion of a multi-piece sprocket including a locating nub and a corresponding shaft including features for engaging the locating nub. [Figure 7] 7 is a cross-sectional view of the assembled multi-piece sprocket of FIG. 1. [Figure 8] 8 is another cross-sectional view of the assembled multi-piece sprocket of FIG. 1. [Figure 9]FIG. 9 is a perspective view of a tool used to assemble the multi-piece sprocket of FIG. 1 according to one embodiment. [Figure 10] FIG. 10 shows the tool of FIG. 9 with the cap portion of FIG. 4 attached. [Figure 11] 11A-11D show the steps involved in assembling a multi-piece sprocket onto a shaft. DETAILED DESCRIPTION OF THE INVENTION

[0010] A multi-piece sprocket or other conveyor component for driving or otherwise engaging a conveyor belt includes multiple portions that fit around a rotatable shaft. Although the present invention is described below with reference to certain exemplary embodiments, the invention is not limited to these exemplary embodiments.

[0011] One form of multi-piece sprocket mounted on a shaft 12 that embodies features of the present invention is shown in Figures 1-3. The exemplary multi-piece sprocket 10 includes two components: a first portion, designated as a base portion 20, and a second portion, designated as a cap portion 60. The cap portion 60 mates with the base portion 20 to form a complete sprocket, which has peripheral drive elements, designated as teeth 25, for engaging drive structure on a conveyor chain or belt. The exemplary teeth are evenly spaced at a constant pitch around the periphery. However, the present invention is not limited to this exemplary drive element configuration; the drive structure may have any suitable size, shape, pitch, and configuration suitable for engaging a conveyor belt or chain, and may alternatively include rollers without drive elements. In this exemplary embodiment, the base and cap portions are interconnected in a puzzle pattern to form a complete sprocket, although any suitable connection means may be used to join the two components together. The present invention is not limited to sprockets that drive conveyor belts, but can include any multi-piece conveyor component that is mounted on a shaft.

[0012] Each component 20, 60 may comprise a single unitary piece or multiple interconnected sub-pieces. In this example, the two components are different shapes, with the first component 20 being the larger component. This exemplary base portion 20 is curved and spans most of the circumference of the sprocket, excluding a space around the periphery, and the cap portion 60 is inserted into this space to complete the circumference when mated with the base portion 60. While the end faces of the components 20, 60 are aligned in the mated position, the invention is not so limited.

[0013] The sprocket 10 includes a collar or central hub 30 that defines a central opening 27 for receiving the shaft 12, as shown in Figures 2 and 3. The shaft is attached to or otherwise connected to the conveyor frame.

[0014] The hub portion 30 is formed within the base portion 20 and is connected to the curved peripheral portion 22 of the base portion 20 by webbing 28 having openings 29, although any suitable means for connecting the central hub portion 30 to the peripheral portion 22 may be used, such as spokes or a solid structure. The exemplary hub portion 30 includes three vertical walls 31, 32, 33 at the base for engaging the shaft 12 and an open end that extends to a passage 40 for receiving the cap portion 60. The passage extends from the peripheral space within the rim 22 to the hub 30 to receive and lock the cap portion 60. The hub portion 30 may have any suitable shape for engaging a shaft and is not limited to a square cross-section as shown.

[0015] The width of the passage 40 is greater than the thickness of the cap portion 60, thereby allowing the cap portion 60 to slide into the passage 40 when oriented perpendicular to the orientation of the assembled sprocket.

[0016] Hub 30 may include a cleaning recess on its interior surface to provide space between shaft 12 and hub 30 for improved cleanliness and ease of cleaning, although the invention is not so limited.

[0017] Base portion 20 further includes an inner curved channel 50 adjacent hub sidewalls 32, 33 and intersecting passageway 40. The inner curved channel extends through base portion from the first face to the second face and curves about radial axis 41 to define passageway 40, i.e., the center of curvature of the curve coincides with radial axis 41. Inner curved channel 50 includes a contoured rounded surface 52. Channel 50 may include two portions that are substantially perpendicular to one another, with a first portion opening into passageway 40 and a second portion parallel to radial axis 41, although the invention is not so limited.

[0018] Base portion 20 further includes an outer curved channel 54 in the peripheral surface. Outer curved channel 54 is also curved about radial axis 41 and extends through base portion from the first surface to the second surface, but is positioned further from radial axis 41 than inner curved channel 50. A curved molding projection 56 extends from passageway 40 between the passageway and outer curved channel 54. The exemplary outer curved channel 54 has a hook-shaped cross-section, although the invention is not so limited.

[0019] Cap portion 60 is configured to be inserted into mold passage 40 when in a first orientation, as described below, and then rotated to a locked position. Prior to inserting cap portion 60, shaft 12 is inserted through mold passage 40 and into central opening 27. Molded passage 40 is configured and sized to allow shaft 12 to pass therethrough.

[0020] The exemplary cap portion 60 includes a shaped body extending along the central axis 42 from a peripheral end 61 configured to complete the periphery of the sprocket 10 to an inner end 62 configured to complete the central opening 27, as shown in Figures 3 and 4. Connecting portions 65, shown as spokes, connect the peripheral end 61 to the inner end 62. The peripheral end 61 includes drive elements that complete the pattern of teeth 25.

[0021] Peripheral edge 61 terminates in a hook 64 configured to be received within outer curved channel 54. The hook forms a shaped curved recess 66 that engages with curved shaped protrusion 56 on base portion 20. This exemplary hook 64 has a flat bottom, a curved tip, and a sloped inner surface that engages with curved shaped protrusion 56 on the base portion, although the invention is not so limited.

[0022] The inner end 62 of the cap portion 60 is configured to engage the inner curved channel 50 and forming surface 52 of the base portion 20. The exemplary inner end includes a flat, radially outer wall 71. The curved sidewall 73 and the curved channel 74 form a curved tab that extends from the first side to the second side and curves around the central axis 42. The curved tab formed by the curved sidewall 73 and the curved channel 74 is designed to be received in the inner curved channel 50, which in turn receives the forming surface 52. The exemplary inner end 62 further includes a recess 76 between surfaces 77 that abut the shaft 12 when the sprocket is assembled.

[0023] An end face of the cap portion 60, such as end face 79, is substantially flat and configured to align with an end face of the base portion 20 when the sprocket is assembled.

[0024] Sprocket 10 may further include a latch for securing base portion 20 and cap portion 60 together. An exemplary latch includes a locking tab 68 on the outer surface of hook 64 of cap portion 60 that engages with a locking recess in outer curved channel 54 of base portion 20, although the invention is not so limited.

[0025] As shown in FIG. 5 , the sprocket 10 is assembled by first inserting the shaft 12 into the passage 40 so that the shaft 12 rests within the hub 30. Then, as shown in FIG. 5 , the cap portion 60 is oriented either perpendicular to the passage 40 or obliquely relative to the longitudinal axis of the shaft 12. In this orientation, the cap portion 60 protrudes longitudinally from the passage 40. The cap portion 60 is moved to an engaged position, where the flat surface 77 abuts the shaft 12 and the radial axes 41, 42 are aligned. The cap portion 60 is then rotated about the radial axis 42, whereby the hook 64 enters the channel 54, the projection formed by the curved sidewall 73 and the curved channel 74 enters the inner curved channel 50 of the base portion 20, and the curved channel 74 of the cap portion 60 receives the molding surface 52 of the base portion 20. The cap portion 60 is rotated, ultimately forming the complete sprocket 10.

[0026] Locking tabs 68 on cap portion 60 may snap into locking recesses 59 on base portion 20 to secure cap portion 60 in the mated position. Other suitable means for hooking the two portions together in the assembled position may also be used.

[0027] As shown in FIG. 6 , the base portion 20 may include an axial locating nub 38 in the wall 31 opposite the passage 40 to facilitate axial positioning of the sprocket 10 on the shaft 12. The exemplary shaft 12 includes locating recesses that engage the axial locating nub. One or more of the shaft locating recesses may be smaller openings, such as round holes 14, to lock the axial position of the sprocket. Other shaft locating recesses may be slots 16 that allow some floating of the mounted sprocket in its position. In other embodiments, the base portion and / or shaft may include cooperating chamfers and / or grooves to facilitate axial placement on the sprocket shaft. Other suitable shaft locating means may also be used, and the invention is not limited to nubs, recesses, grooves, and / or chamfers.

[0028] 7 and 8 are cross-sectional views of sprocket 10 assembled to shaft 12 with locating tabs 38 engaged with locating recesses 14, illustrating the engagement between the hooks and channels when cap portion 60 engages base portion 20.

[0029] 9 and 10, a tool 110 can be used to insert the cap portion 60 into the molding passage 40 of the base portion 20 and rotate it therein to form the complete sprocket 10. The exemplary tool 110 includes a handle 112 and a loading portion 114 extending from the handle 112. The loading portion 114 includes a base 116 and a pair of spaced apart parallel legs 118, 119 for holding the cap portion 60 therebetween, as shown in FIG.

[0030] The legs 118, 119 may have inner bars 120, 121 that contact corresponding recesses in the face of the cap portion 60 to facilitate handling of the cap portion 60.

[0031] 11A-11D illustrate the steps involved in assembling an exemplary sprocket 10 to a shaft 12 using a tool 110. First, as shown in FIG. 11A, the shaft 12 is inserted through the passage 40 into the hub 30 to a selected axial location. The cap portion 60 is loaded onto the tool 110 and carried above the passage 40. In the insertion orientation shown in FIGS. 11A and 11B, the legs 118, 119 of the tool 110 face the walls of the passage 40, and the cap portion 20 is oriented at an angle relative to the assembly position. For example, the cap portion 20 can be oriented such that the curved sidewall 73 and locking tab 68 face the length of the shaft 12 and protrude from the passage 40. In this orientation, the tool and cap portion fit into the passage 40, and the axis 42 of the cap portion 60 is aligned with the axis 41 of the passage.

[0032] Once the flat surface 77 on the inner end of the cap portion 60 abuts the shaft 12, the tool 110 rotates the cap portion 60 about the axes 41, 42 to engage the cap portion 60 with the base portion 20, as shown in Figures 11C and 11D.

[0033] The tool 110 can then be removed, leaving the completed sprocket 10 mounted on the shaft 12.

[0034] The sprocket can be disassembled by reversing the process.

[0035] Although the present invention has been described with respect to one form of sprocket, other forms are possible. For example, the periphery may be toothless, smooth like a roller, or grooved like a pulley. Thus, the term sprocket as used in the claims is intended to include a multi-piece wheel with or without teeth on its periphery.

Claims

1. 1. A sprocket for a conveyor belt, comprising: A first sprocket component, a curved peripheral portion that contacts the conveyor belt; a hub radially inward of said peripheral portion for receiving a shaft; a passageway extending along a radial axis from a space within the curved peripheral portion to the hub; a first set of curved channels extending through the first sprocket component from the first face to the second face, the first set of curved channels curving about the radial axis; a first sprocket component including: a second sprocket component inserted into the passageway to complete the peripheral portion and hub, a first set of curved projections configured to be received within the curved channel when the second sprocket component is rotated about the radial axis from a first orientation in which the second sprocket component is inserted into the passageway to a mating position that completes the peripheral portion and hub; a second sprocket component including: Including sprockets.

2. The sprocket of claim 1 , wherein said first set of curved channels is adjacent said hub.

3. 3. The sprocket of claim 2, wherein said first sprocket component includes second curved channels formed in said peripheral portion for receiving hooks of said second sprocket component.

4. 4. The sprocket of claim 3, wherein the second set of curved channels includes locking recesses for receiving locking tabs on outer surfaces of the hooks of the second sprocket component to lock the sprocket component to the second sprocket component.

5. 2. The sprocket of claim 1, wherein said curved peripheral portion includes a drive element for driving said conveyor belt.

6. 2. The sprocket of claim 1, wherein each curved channel includes a first portion that opens into the passageway and a second portion that is substantially perpendicular to the first portion.

7. 2. The sprocket of claim 1, wherein said hub includes an axial locating nub on said wall opposite said passageway to facilitate axial positioning of said sprocket on said shaft.

8. 2. The sprocket of claim 1, wherein the second sprocket component includes a neck extending along a central axis from a peripheral end configured to complete a curved peripheral edge to an inner end configured to complete the hub and define a central opening for a shaft.

9. 9. The sprocket of claim 8, wherein the peripheral edge of the second sprocket component includes hooks defining formed curved recesses configured to be received within the first set of curved channels of the first sprocket component.

10. 9. The sprocket of claim 8, wherein the inner end includes a curved sidewall and a curved channel inset from the curved sidewall to form a protrusion configured to be received in the curved channel of the first sprocket component, and wherein flat, radially outer and inner walls are configured to abut a shaft when the sprocket is assembled.

11. 1. A sprocket for a conveyor belt, comprising: A first sprocket component, a curved peripheral portion defining the drive element; a hub radially inward of said peripheral portion for receiving a shaft; a passageway extending along a radial axis from a space within the curved peripheral portion to the hub; a first set of curved channels in a peripheral surface of the peripheral portion forming a curved shaped projection between the passageway and the first set of curved channels; a second set of curved channels adjacent the hub, the second set of curved channels intersecting the passageway and extending through the first sprocket component from the first face to the second face; a first sprocket component including: a second sprocket component inserted into the passageway to complete the peripheral portion and hub, hooks at the peripheral edges configured to be received in the first set of curved channels; a second sprocket component including: a curved tab at an inner end configured to be received in the second set of curved channels; and wherein the second sprocket piece is rotated about the radial axis from a first orientation in which the second sprocket piece is inserted into the passageway to a mating position in which the second sprocket piece completes the peripheral portion and hub.

12. 12. The sprocket of claim 11, wherein said first and second sets of curved channels are curved about said radial axis.

13. 12. The sprocket of claim 11, wherein said hub includes an axial locating nub on a wall opposite said passageway to facilitate axial positioning of said sprocket on said shaft.

14. 12. The sprocket of claim 11, further comprising a locking tab and a corresponding locking recess for locking said first sprocket component to said second sprocket component in said mated position.

15. 15. The sprocket of claim 14, wherein said locking tabs are formed on outer surfaces of hooks of said second sprocket component and said locking recesses are formed in said first set of curved channels.

16. 1. A sprocket assembly for a conveyor belt, comprising: a shaft connected to the conveyor frame, the shaft including an opening in an outer surface; A split sprocket attached to the shaft, a first sprocket component including an open hub for receiving the shaft, a locating nub in a wall of the open hub configured to engage the opening in the shaft, a passage along a radial axis between the hub and the peripheral portion, and at least one curved channel extending from a first surface to a second surface; a second sprocket component including at least one curved projection configured to be received within the curved channel, the second sprocket component being rotated about the radial axis from a first orientation in which the second sprocket component is inserted into the passage to a mating position that completes the peripheral portion and the hub; Including the sprocket assembly.

17. The sprocket assembly of claim 16, wherein said openings on said shaft outer surface are slots.

18. 17. The sprocket assembly of claim 16, further comprising a tool including spaced parallel legs for holding the second sprocket component and rotating it about the radial axis to form the sprocket.

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