Return roller assemblies for conveyor

A return roller assembly that is designed for use as part of a conveyor assembly to improve the ability to clean the conveyor assembly. The return roller assembly includes a roller shaft that extends between side walls of a conveyor frame. A plurality of support rollers are positioned along the length of the roller shaft to support a lower run of a continuous conveyor belt. A spacer is positioned between each of the support rollers to define the position of the rollers along the roller shaft. The spacer can be snapped onto the roller shaft and includes a series of standoffs that space the inner surface of the spacer from the roller shaft. A series of cleaning fins extend radially from the outer surface of the spacer and impart rotation to the spacer relative to the roller shaft during cleaning with a spray of water. The spacer can be formed from an extrusion cut to length.

BACKGROUND

The present disclosure generally relates to return roller assemblies that are part of a conveyor having a conveyor belt. More specifically, the present disclosure relates to one or more extruded spacers that are used to space return rollers along a return roller shaft and can be installed and removed quickly and cleaned in place.

Presently, in food processing conveyor applications, conveyors must be manufactured such that the conveyor belt can be removed and the entire conveyor frame assembly sanitized. Following sanitation, the conveyor belt must be reinstalled for continued operation. Numerous guidelines exist to regulate the type of conveyor assembly that be used in a sanitary environment, such as in a food processing facility. Typically, these guidelines require that the conveyor frame assembly must be capable of being disassembled and sanitized on a regular, scheduled basis. Since the conveyor frame assembly must be sanitized regularly, the conveyor assembly must be capable of being quickly disassembled to allow complete cleaning. Preferably, the disassembly should require minimal tool to no tools.

The present inventors have recognized drawback and limitations with current conveyor assemblies that included return roller assemblies and have developed the system of the present disclosure.

SUMMARY

The present disclosure relates to a return roller assembly for use with a conveyor assembly. More specifically, the present disclosure relates to a return roller assembly that supports the lower run of a continuous conveyor belt and includes a series of spacers that can be easily removed and installed and cleaned in place when desired.

The return roller assembly designed for use in supporting a lower run of a continuous conveyor belt includes a roller shaft that extends across and is supported by side walls of a conveyor frame. the roller shaft is stationary and has a circular cross section defined by an outer surface. The roller shaft provides support for a plurality of rollers that are each movable along the longitudinal length of the roller shaft. The rollers each include an outer surface that contact the lower run of the conveyor belt to support the conveyor belt during operation.

The spacing between the rollers is dictated and defined by a plurality of spacers that are attached to the roller shaft between the plurality of rollers. The spacers are each formed from a section of an extruded plastic material that is cut to the desired length. The spacers each have a generally circular outer wall that extends between first and second ends. When the spacer is installed on the roller shaft, the first and second ends of each spacer contact either one of the rollers or one of the side walls to control the spacing of the rollers along the roller shaft.

Each of the spacers includes a access opening that is a missing portion of the outer wall. The access opening is defined by first and second edges. The width of the access opening is less than the outer diameter of the roller shaft. When the spacer is installed on the roller shaft, the outer wall of the spacer flexes to expand the width of the access opening, which allows the spacer to snap into place on the roller shaft. Once installed, the outer wall flexes to hold the spacer on the roller shaft.

The spacers each include a plurality of standoffs that extend radially inward from an inner surface on the outer wall of the spacer. The standoffs contact an outer surface of the roller shaft to create an air gap between the roller shaft and in outer wall of the spacer. The air gap allows water to pass between the spacer and the roller shaft during cleaning with water or another cleaning fluid.

The spacers further include a plurality of cleaning fins that extend radially outward from an outer surface of the outer wall of the spacer. The cleaning fins are spaced along the circular outer wall. During cleaning with a spray of water, the spray of water contacts the cleaning fins and causes the entire spacer to rotate around the roller shaft. Since the spacer includes the series of standoffs, the rotation created by the contact between the spray of water and the cleaning fins causes the standoffs to pass over the outer surface of the roller shaft to scrape material off of the roller shaft.

The present disclosure further relates to a conveyor assembly that includes a conveyor frame and a continuous conveyor belt that is movable along the length of the conveyor frame. The conveyor assembly includes a plurality of roller assemblies as described to support the lower run of a continuous conveyor belt.

DETAILED DESCRIPTION

FIG.1illustrates a conveyor assembly10constructed in accordance with the present disclosure. The conveyor assembly10generally includes a conveyor frame12that includes a pair of side walls14that define the width of the conveyor assembly10. The side walls14are each connected to a series of legs16that are spaced along the length of the conveyor frame12and support the entire conveyor assembly10above a support surface, such as a floor. The conveyor assembly10includes a continuous conveyor belt18that extends along the entire length of the conveyor assembly10. The continuous conveyor belt18defines an upper run20and a lower run22. The upper run20of the conveyor belt18supports objects as they move along the length of the conveyor assembly10while the lower run22returns the conveyor belt to the infeed end. The conveyor belt18moves along the length of the conveyor assembly and transitions between the upper and lower runs around a pair of end rollers24. One of the end rollers, shown inFIG.1, is an idler/tension roller while the opposite end roller (not shown) is driven by an electric drive motor to impart the required movement to the conveyor belt18. In the embodiment shown inFIG.1, the end roller24includes a tension adjustment assembly26that allows an operator to introduce the required tension into the conveyor belt18to compensate for stretching of the conveyor belt18over the life span of the conveyor belt18.

As shown inFIG.1, each of the side walls14includes a lower flange28that is used to support a plurality of return roller assemblies30along the length of the conveyor frame12. The return roller assemblies30each provide support for the lower run22of the conveyor belt18as the lower run22moves between the pair of spaced end rollers24. In the embodiment shown inFIG.2, a pair of return roller assemblies30are shown over the partial length of the conveyor belt18. It is contemplated that the number of return roller assemblies30would depend upon the overall length of the entire conveyor assembly10. The spacing between the return roller assemblies30is selected to prevent excess sagging of the lower run22of the conveyor belt and can vary depending on the type of conveyor belt, the operating speed of the conveyor belt and the width of the conveyor assembly.

FIGS.2and3illustrate the components of each of the return roller assemblies30constructed in accordance with the present disclosure.FIG.2shows the return roller assembly30in an assembled condition whileFIG.3is an exploded view showing the return roller assembly30in a disassembled condition.

As shown inFIG.3, the return roller assembly includes a roller shaft32that extends between a first end34and a second end36. Each of the first and second ends34,36includes a support tab38that extends from the respective end. The support tab38is designed to be received within a corresponding slot40formed in the lower flange28of the side wall14, as best shown inFIG.1. The interaction between the slot40and the support tab38prevents rotation of the roller shaft32when the roller shaft32is supported across the width of the conveyor frame between the side walls14. The roller shaft32has a circular cross section defined by an outer surface42that defines the diameter of the roller shaft32. In the embodiment illustrated, the roller shaft32is formed from a metallic material that is both durable and can be cleaned and sanitized, such as stainless steel. However, other materials could be used in place of stainless steel while operating within the scope of the present disclosure.

In the embodiment shown inFIGS.2and3, the return roller assembly30includes a plurality of support rollers44that are spaced along the length of the roller shaft32between the first end34and the second end36. Each of the rollers44includes a circular outer support surface46. The outer support surface46is designed to contact the lower run22of the conveyor belt18, as shown inFIG.1. The outer support surface46is reinforced and radially supported by a series of support spokes48that extend from a center hub50out to the support surface46. Each of the rollers44further includes a center wall52that extends from the hub50out to the support surface46. In the embodiment illustrated, each of the rollers44is formed from a molded plastic or nylon material that can be readily cleaned and is lightweight and sufficiently strong to support the weight of the lower run22of the conveyor belt as illustrated inFIG.1.

As can be seen inFIGS.2and3, the center hub50includes an open gap54that allows water to access the area of the roller shaft32directly below the roller diameter. The open gap54in the center hub50of each of the rollers44further aids the cleaning of the roller assembly30while the spacers56remain in place and provide the desired spacing between the rollers44. During operation, each of the rollers44are rotatable about the stationary roller shaft32as the lower run22of the conveyor belt18moves over the support rollers44.

In the embodiment of the disclosure shown inFIGS.2and3, a plurality of individual spacers56are used to provide the required and desired spacing between the individual rollers44along the length of the roller shaft32. A pair of end spacers56A and56D provide the required spacing between the outer most rollers44and the adjacent side wall14. The pair of center spacers56B and56C provide the required spacing between the individual rollers44as illustrated. In this manner, the length of each of the individual spacers56controls the position of the rollers44along the length of the roller shaft32and thus the spacing between the support rollers44along the length of the roller shaft32. In the embodiment shown best inFIG.3, each of the spacers56A-56D each have the same configuration and are each formed from the same extrusion of a plastic or nylon material. The individual spacers56are cut to the desired length to dictate the spacing between the side walls and the outermost rollers44as well as the spacing between the individual rollers44along the length of the roller shaft32.

Referring now toFIGS.3and4, each of the spacers56is defined by a generally cylindrical outer wall58that extends between a first end57and a second end59to define the longitudinal length of the spacer56. The outer wall58of each spacer56includes an outer surface60and an inner surface62that are spaced from each other to define the thickness of the outer wall58. The outer wall58has a generally circular cross section with a removed portion that defines an access opening64. The access opening64that is a missing portion of the otherwise circular outer wall58and is defined by a first edge66and a second edge68. The access opening64allows the spacer56to be installed onto the circular outer surface42of the roller shaft32when moving the spacer56in a direction shown by arrow70inFIG.4. In the embodiment illustrated, the diameter D of the roller shaft32is larger than the width W of the access opening64. When the spacer56is moved downward in the direction shown by arrow70, the first edge66and the second edge68contact the outer surface42and flex outward as shown by arrows72inFIG.5until the width W of the access opening64expands to be equal to the diameter D of the roller shaft32. The thickness of the outer wall58and the material used to create the extrusion are both factors in providing enough flexure in the spacer56to allow for the installation as shown.

Once the first and second edges66,68of the spacer56pass over the equator of the roller shaft32, the flexible material that forms the outer wall58causes the spacer56to flex back to its resting position to move the first edge66and the second edge68toward each other to securely hold the spacer56on the roller shaft32as is shown inFIG.6.

As illustrated inFIGS.4-6, the inner surface62of the outer wall58that defines the spacer56includes a series of standoffs74that each protrude radially inward from the inner surface62. The standoffs74in the embodiment illustrated extend along the entire length of the spacer56. However, it is contemplated that the standoffs74could be interrupted along the length of the spacer56to create sections of standoffs74. In the embodiment illustrated, the entire spacer56is an extruded plastic component and each of the standoffs74extends along the length of the standoff.

Referring now toFIG.6, when the spacer56is installed onto the roller shaft32, each of the standoffs74contacts the outer surface42of the roller shaft32to create an air gap76. The air gap76is the area that is located between the outer surface42of the roller shaft32and the inner surface62of the outer wall58of the spacer56. The air gap76extends along the entire length of the spacer56from the first end57to the second end59. The size of the air gap76is dictated by the distance the standoff74protrudes radially inward from the inner surface62.

As can be seen inFIGS.4-6, a standoff74is formed along both the first edge66and the second edge68such that each of the first and second edges is spaced away from the outer surface42of the roller shaft32.

As illustrated inFIGS.2-6, each of the spacers56is formed with a plurality of cleaning fins78that each extend radially from the outer surface60of the outer wall58. In the embodiment shown, the spacer56includes five cleaning fins78that are spaced around the outer periphery of the generally cylindrical outer wall58. However, fewer or more cleaning fins78could be included on the spacer56. As illustrated inFIGS.4-6, one of the cleaning fins78is formed at each of the first edge66and the second edge68that define the access opening64. The location of cleaning fins78at the first and second edges66,68allow for easier removal of the spacers56when needed. Specifically, when the spacer56needs to be removed, a user can apply outward pressure to each of the cleaning fins78at the first and second edges to expand the width of the access opening while also applying upward pressure. Such forces and movement will allow the spacer56to be removed in a sequence opposite to that shown inFIGS.4-6described during the installation process of the spacer56.

Referring back toFIG.6, when the spacer56is installed on the roller shaft32, the standoffs74create three points of contact between the spacer56and the roller shaft32. The air gap76created between the spacer56and the roller shaft32minimizes the points of contact, which creates a more sanitary configuration. In addition, the air gap76allows water to flow between the roller shaft32and the spacer56during cleaning and/or pressure washing of the entire conveyor assembly.

Referring now toFIGS.7-9, the operation of the return roller assemblies30in improving the cleaning of the conveyor assembly will be described. As shown inFIG.7, the outer support surface46of each of the rollers44contacts the lower surface80on the lower run22of the conveyor belt. If the operator of the conveyor assembly desires to clean the conveyor assembly, the operator can utilize a hose82to spray a supply of water84in a direction toward the roller shaft32when the spacer56remains installed on the roller shaft32. Typically, the conveyor belt will be removed from the conveyor assembly before the cleaning process begins. However, since the spacers56do not contact the conveyor belt, cleaning could take place with the conveyor belt still in place as illustrated. As shown inFIG.7, the spray of water84can be directed upward and tangential to the outer surface of the roller shaft32.

As water is sprayed upward and in a direction toward the spacer56, the spray of water contacts the series of cleaning fins78. Since the entire spacer56is rotatable about the roller shaft32and is contact with the roller shaft32at only the standoffs74, the spray of water84will cause the entire spacer56to rotate in a direction as illustrated by arrows86inFIG.8. Since the spacer56has a series of cleaning fins78spaced around its perimeter, the spacer56will continue to rotate even as the access opening64passes through the water spray84. The spacer56will continue to rotate in the direction shown by arrows86as long as the spray of water84is supplied.

During the rotation of the spacer56, the three points of contact created by the standoffs74tend to scrape and clean the outer surface of the roller shaft and act as a squeegee to remove any dirt or other material that may be present on the roller shaft. The air gap created by the standoffs74allows the cleaning water to pass between the spacer56and the outer surface of the roller shaft32. During the cleaning process, the spacer56will rotate at a relatively high RPM which will further aid in cleaning both the spacer56and the outer surface of the return shaft32. In this manner, the return roller assembly30can be cleaned in much less time than previous embodiments in which the rollers44are held in place by stationary clips along the length of the roller shaft30.

As can be understood inFIGS.1-3, each of the spacers56can be removed and installed onto the roller shaft32when the roller shaft is installed beneath the conveyor frame. Each of the individual spacers56can be snapped into place separately to define the required spacing between the rollers44. Since each of the spacers56is rotatable about the stationary roller shaft32, the spacers56can be pushed upward onto the roller shaft32and rotated into position as desired. Likewise, when any one of the spacers56needs to be removed, the spacer56can be rotated such that the user can access the cleaning fins78aligned with each of the first and second edges66,68. The user can then separate the first and second edges to remove the spacer from the roller shaft32.

In the embodiment shown in the figures, each of the spacers56is formed from a section of excluded material. Each of the spacers56can be cut to the desired length from a continuous piece of material that has the cross sectional configuration shown in the drawing figures. In this manner, the spacing between the individual rollers44can be dictated as desired and based upon the overall width of the conveyor assembly. In the embodiment illustrated, each of the spacers56is formed from a section of extruded plastic material that is both durable and can be sanitized during a cleaning process. However, it is contemplated that other materials could be used while operating within the scope of the present disclosure.