Patent Application
20070261933
The present invention relates to the field of conveyor rollers and, more particularly, to conveyor rollers having stub shafts and conveyor roller inserts for mounting conveyor rollers to support frames.
Conveyor systems utilizing rollers are widely used in a variety of industrial applications. In a typical configuration, a plurality of closely spaced, freely-rotating conveyor rollers are mounted in parallel to an elongate support frame. The structure for mounting the rollers to the support frame is integral with the rollers. In some conveyor roller designs, inserts are mounted in each end of the roller tube and include protrusions projecting outwardly from the ends of the tube which are received within opposing pairs of mounting holes provided on the conveyor frame. Consequently, each conveyor roller assembly is independently attachable to and removable from the conveyor support frame.
Such a structure is advantageous in terms of flexibility of design and ease of maintenance. However, in order to provide rollers of different diameters or rollers having one end which is larger than the other (e.g., tapered rollers), manufacturers must produce inserts having a variety of outer diameters.
One embodiment of the present invention provides a conveyor roller insert for a conveyor roller tube having:
Another embodiment of the present invention provides a conveyor roller, comprising an elongate roller tube having first and second ends and first and second roller inserts inserted into the first and second ends of the roller tube. Each of the roller inserts may comprise a cartridge, stub axle and at least one bearing, as described above. At least one (and optionally both) of the inserts further includes an annular sleeve configured to be inserted into an end of the roller tube, wherein the cartridge of that roller insert is securely and non-rotatably positioned within the annular sleeve.
The present invention also provides a conveyor roller having an elongate roller tube and a roller insert inserted into each end of the roller tube.
The following detailed description will be more fully understood in view of the drawings in which:
The embodiments set forth in the drawings are illustrative in nature and are not intended to be limiting of the invention defined by the claims. Moreover, individual features of the drawings and the invention will be more fully apparent and understood in view of the detailed description.
The present invention is directed to conveyer roller assemblies and conveyor roller inserts for use in conveyor roller tubes. In particular embodiments, a conveyor roller insert is provided, wherein that insert includes not only a cartridge having a stub axle rotatably mounted therein, but also an annular sleeve within which the cartridge is securely positioned. The inner diameter of the annular sleeve is sized and configured so as to snugly receive the cartridge therein, while the outer diameter of the sleeve is sized and configured such that it may be secured within the open end of a roller tube. The outer diameter of the sleeve may be varied in order to accommodate roller tubes of different sizes, without altering the size or configuration of the cartridge or any of the additional components of the insert positioned within the cartridge. In this manner, the same cartridge assembly may be used in roller tubes of varying sizes simply by inserting the cartridge into an annular sleeve having the appropriate outer diameter.
Other embodiments of the present invention provide conveyor roller assemblies comprising a roller tube and a roller insert inserted into each end of the roller tube. One or both of the inserts may utilize the annular sleeve described above. In one particular embodiment comprising a tapered conveyor roller assembly wherein the inner diameter of the roller tube at one end is greater than the inner diameter at the opposite end, one of the inserts may include the annular sleeve (which effectively increases the outer diameter of the insert) while the other does not. Alternatively, each of the inserts may employ an annular sleeve, wherein one of the sleeves has a larger outer diameter than the other. In this manner, tapered conveyor roller assemblies may be provided wherein the cartridge, stub axle and bearing assemblies are identical to one another.
In the embodiment of
In the embodiment shown in
First and second annular sleeves 25A and 25B may be sized and configured to fit into the opened end portions 12 and 13, respectively, of conveyor tube 11. In particular, the outer diameter of annular sleeves 25A and 25B may be equal to or slightly less than the inner diameter of the end portions 12 and 13 of conveyor roller tube 11. In this manner, annular sleeves 25A and 25B may be securely and non-rotatably positioned within opposite ends of roller tube 11. Once again, adhesives, heat welding or other means known to those skilled in the art may be employed to ensure that annular sleeves 25 remain securely and non-rotatably positioned within the ends of roller tube 11.
In the embodiment shown in
Sidewall 23 of annular sleeve 25 may also taper inwardly adjacent inner end 28 of the sleeve, as shown. Tapered portion 29 adjacent inner end wall 28 facilitates insertion of the annular sleeve into the end of roller tube 11 during assembly.
Cartridge 30 may also include a sloped shoulder 38 extending about the interior periphery adjacent inner end 37. As further described herein, and as described in the '825 patent, sloped shoulder 38 facilitates the attachment of a bearing retainer member 80 to the inner end 37 of cartridge 30.
Cartridge 30 further includes a bearing assembly 34 having inner and outer races and a ring of balls captured there between. The outer race of bearing assembly 34 is seated and captured within a groove 35 formed in the interior wall of cartridge 30 adjacent outer end 36. Since cartridge 30 (as well as sleeve 25) may be made from a polymeric material, such as an electrically conductive thermoplastic (e.g., electrically conductive polypropylene), cartridge 30 may be molded around bearing 34 in order to encapsulate and retain bearing 34 within cartridge 30.
As best seen in
In the exemplary embodiment of
In the embodiment shown in
As mentioned previously, a bushing 60 may be positioned within bearing 34, as seen in
Bushing 60 also includes a circumferential groove 62 extending about its outer surface, wherein groove 62 is sized and configured such that the inner race of bearing 34 may be at least partially positioned within the groove 62. When positioned in this manner, the inner race of bearing 34 will essentially be attached to bushing 60 such that cartridge 30 is rotatable with respect to bushing 60.
Bushing 60 may further include a flange 63 located distally with respect to groove 62. Flange 63 is configured to cover and protect bearing 34, and may have an outer diameter slightly less than the inner diameter of outer end 36 of cartridge 30. In this manner, flange 63 will not interfere with the rotation of cartridge 30 with respect to bushing 60 and axle 40. In addition, flange 63 may be slightly spaced distally from groove 62 such that, when bushing 60 is installed as shown, a slight gap will exist between inner surface 69 of flange 63 and bearing 34. Bushing 60 may further include an extension 64 located between distal end surface 65 and flange 63. Extension 64 will provide additional support for axle 40, and its outer surface may have a hexagonal cross-sectional shape corresponding to the hexagonal shape of central bore 61.
At its proximal end, bushing 60 may be slotted such that a plurality of fingers 67 are provided. In particular, and as shown in FIGS. 6 and 7 of the '825 patent, a plurality of grooves 70 extend from proximal end 66 of bushing 60 in the axial direction. With respect to hexagonal central bore 61, grooves 70 are located on the flat portion of the hexagonal cross-section. In this manner, six fingers 67 are provided. When viewed in cross-section, the outer surface of each finger 67 will comprise a circular segment. The cross-sectional shape of the inner surface 68 of each finger 67 will be angular in nature, as best seen in the end view of FIG. 7 of the '825 patent.
In the embodiment shown in FIGS. 5-7 of the '825 patent, grooves 70 extend beyond the midpoint of outer circumferential groove 62. In addition, at least a portion of the inner surface 68 of fingers 67 taper outwardly, as indicated by angle A in FIG. 6 of the '825 patent. In the embodiment shown therein, inner surface 68 is not tapered along the entire length of each finger 67. In particular, inner surface 68 of finger 67, when viewed in the axial cross-section of FIG. 6 of the '825 patent, tapers outwardly from a line 72 spaced away from the base 73 of finger 67. In this manner, each finger 67 is cantilevered from line 72. In other words, each finger 67 includes a base portion having a non-tapered inner surface, and a cantilevered portion having a tapered inner surface.
Because the inner surface 68 of fingers 67 taper outwardly, a force applied axially against proximal end surface 66 of bushing 60 will cause fingers 67 to flex outwardly. For example, and as further described herein, axle 40 may include a flange 46 positioned such that flange 46 is biased against proximal end surface 66 of bushing 60. As fingers 67 of bushing 60 are urged outwardly, projections 72 which define the proximal end wall of groove 62 on bushing 60 will prevent bushing 60 from being forced out of roller insert 20. The proximal end wall 71 of projections 72 may be tapered in order to facilitate the insertion of bushing 60 into roller insert 20.
In the embodiment shown in
Bearing retainer assembly 80 is generally tubular in nature, and includes a central passageway 86. The outer race of bearing 84 is seated and captured within a groove 85 formed in the interior side wall of bearing retainer member 80. Like cartridge 30, bearing retainer assembly 80 may be made from a polymeric material, particularly an electrically conductive thermoplastic such as electrically conductive polypropylene. Therefore, bearing retainer assembly 80 may be molded around bearing 84 in order to encapsulate and retain bearing 84 therein. The inner race of bearing 84 defines a central passageway 87 which is sized and configured to slidingly receive and support a rod portion 47 provided an axle 40, as further described herein.
On its outer surface, bearing retainer assembly 80 includes an outer lip 88 extending about the outer circumference of bearing retaining assembly 80. Outer lip 88 is sized and configured such that bearing retainer assembly 80 may be inserted into the inner end portion of cartridge 30 with lip 88 seated against inner end wall 37 of cartridge 30. A shoulder 89 is also provided, and is spaced distally from lip 88. When bearing retainer assembly 80 is inserted into the inner end portion of cartridge 30, shoulder 89 will abut against sloped shoulder 38 on cartridge 30. This configuration will facilitate the welding (such as by sonic welding) of bearing retainer assembly 80 to the inner end portion of cartridge 30. Furthermore, bearing retainer assembly 80 includes a distal end portion 90 having a cylindrical outer surface. Distal end portion 90 is sized and configured to be snugly received into the inner end portion of cartridge 30, as shown in
Stub axle 40 may include a rod portion 47 extending away from elongate body portion 41 at the proximal end thereof. The proximal or inner end 48 of rod portion 47 may also be tapered as shown in order to facilitate insertion of rod portion 47 into central passageway 87 formed by the inner race of second bearing 84. Rod portion 47 is sized and configured to be slidably received in central passageway 87. In this manner, the inner race of second bearing 84 will support rod portion 47 while still allowing slidable movement of the axle relative to both first bearing 34 and second bearing 84. Second bearing 84 will also facilitate rotational movement of cartridge 30 relative to axle 40.
As mentioned previously, axle 40 may be biased outwardly from cartridge 30 such that the outer end portion of the axle will project outwardly from outer end 36 of cartridge 30. However, the outer end portion of the axle can be urged inwardly in order to facilitate insertion of the outer end portion of the axle into a mounting hole on a conveyor frame.
In the embodiment shown, axle 40 further includes a flange 46 located between elongate body portion 41 and rod portion 47. In the embodiment shown, flange 46 may be any of a variety of shapes. However, the outer diameter of flange 46 should be greater than the outer diameter of bushing 60 at proximal end surface 66. In the exemplary embodiment shown, flange 46 has a circular cross-sectional shape.
As best seen in
In the embodiment shown in
All of the components of conveyor roller insert 20 may be made from electrically conductive materials. For example, axle 40, other than end cap 50, may be made from a metal such as steel. As mentioned previously, end cap 50 may be made from an electrically conductive polymeric material such as electrically conductive polyurethane. Cartridge 30, annular sleeve 25, bushing 60 and bearing retainer assembly 80 may also be made from an electrically conductive polymeric material, such as an electrically conductive thermoplastic (e.g., electrically conductive, glass-reinforced polypropylene). Of course any of a variety of other materials may be used for each of these components.
The conveyor rollers of the present invention may also include sound-absorptive material within the roller tube, as further described in the '099 application.
The specific illustrations and embodiments described herein are exemplary only in nature and are not intended to be limiting of the invention defined by the claims. Further embodiments and examples will be apparent to one of ordinary skill in the art in view of this specification and are within the scope of the claimed invention.
