BACKGROUND AND SUMMARY
The disclosure is directed to a sleeve for a wheel. More in particular, the disclosure is related to a sleeve for a wheel of a caster that may be removably inserted into a bore of a rotation surface, e.g., an inner race of a bearing, that is disposed in a hub of a wheel. The sleeve has an outer surface with a circumferential groove adapted and configured to receive a resilient ring. The resilient ring is configured to be compressible to allow the sleeve to be inserted into the bore of the rotation surface, e.g., the inner race of the bearing. The resilient ring is configured to be expandable outward when the sleeve is inserted through the bore of rotation surface, e.g., the inner race of the bearing, at distance that clears the effective axial length of the rotation surface. The outward expansion of the ring is greater than an inner diameter of the bore of rotation surface, e.g., the inner race of the bearing, and thus, the sleeve may be retained in the bore of the rotation surface to facilitate assembly of the caster with a yoke and axle pin. The resilient ring is also configured to be sufficiently deformable to allow the sleeve to be removed from the bore of the rotation surface as may be required during assembly of the caster.
DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view of an exemplary wheel used in a caster with an exemplary sleeve assembly installed in a hub of the wheel.
FIG. 2 is a perspective view of an exemplary sleeve assembly comprising a sleeve and resilient ring.
FIG. 3 is a cross-sectional view of the sleeve of FIG. 2 taken along a longitudinal axis of the sleeve assembly.
FIG. 4 is a cross-sectional view of the wheel of FIG. 1 taken along an axis of rotation of the wheel.
FIG. 5 is an enlarged view of detail area 5-5 of FIG. 4.
FIG. 6 is an exploded cross-sectional view of the wheel of FIG. 4 showing assembly with an axle pin and yoke of the caster.
DETAILED DESCRIPTION
The description that follows refers to a sleeve assembly that is used with a wheel for a caster. The sleeve assembly may be used with other wheels as well. Referring to FIG. 1, the exemplary caster 10 has a wheel 12 with a hub 14. The hub 14 may be monolithically formed with the wheel or may be integral with the wheel for instance, through an overmolding process, a press fit installation, mechanical and/or adhered connection as is known in the art. A rotation surface 16 may be disposed in the hub 14 and configured to allow the wheel 12 to rotate about a rotation axis 18. The rotation surface 16 may define the radially innermost rotation surface of the wheel hub 14. The rotation surface 16 may be a portion of the wheel hub, a bushing, a journal, a sleeve, or an inner race of a bearing disposed in the hub where the bearing has inner and outer races and rotational elements disposed between the inner and outer races. A rotation surface 16 may be provided on one axial end of the hub 14, and a second rotation surface may be provided on the other axial end of the hub. The rotation surface 16 may extend partially through the hub 14. The rotation surface 16 may have an axial length 20 and a bore 22 with an inner surface diameter 24. For instance, as best shown in FIG. 4, a rotary bearing 30 is inset in a recess 32 formed in the side face of the hub 14 with an inner race 34 defining the rotation surface 16 with the inner race having the bore 22 with the inner surface diameter 24 and the axial length 20 extending partially through the hub.
Referring to FIGS. 2 and 3, the caster wheel 12 includes a sleeve 40 that may be insertable in the bore 22 of the rotation surface 16. The sleeve 40 may have an outer surface 42, and first and second opposite axial ends 44,46. The first axial end 44 of the sleeve 40 may have a shoulder 48 extending radially outward from the outer surface 42 of the sleeve. The shoulder 48 may have inner and outer faces 50,52. The sleeve outer surface 42 of the sleeve 40 may have a circumferential groove 54. A resilient ring 56 may be disposed in the circumferential groove 54 of the sleeve outer surface 42. The resilient ring 56 and circumferential groove 54 may be configured and dimensioned to allow the resilient ring to be retained in the circumferential groove while allowing the resilient ring to expand and compress as needed in manner described below. The resilient ring 56 may have an outer diameter 58. The sleeve outer surface 42 may cylindrical and aside from the circumferential groove 54 may be devoid of other surface features. The resilient ring 56 may be an o-ring. The resilient ring 56 may be configured to be compressible in the circumferential groove 54 in a manner such that the resilient ring outer diameter 58 may be compressed to a resilient ring compression diameter sufficient to enable the sleeve 40 to be inserted in the bore 22 of the rotation surface 16. The resilient ring 56 may be configured to be expandable in the circumferential groove 54 such that the resilient ring outer diameter 58 may expand to a resilient ring expansion diameter greater than the inner surface diameter 24 of the bore 22 of the rotation surface 16 when the resilient ring 56 is unconstrained about the resilient ring outer diameter, for instance, when the resilient ring passes through the bore of the rotation surface and clears the effective axial length of the bore of the rotation surface. Referring to FIGS. 4 and 5, the inner face 52 of the shoulder 48 of the sleeve 40 may positioned to abut a face of the rotation surface 16 when inserted in the bore 22 of the rotation surface. Accordingly, the circumferential groove 54 of the sleeve outer surface 42 may be spaced from the shoulder inner face 52 at a distance sufficient to enable the resilient ring outer diameter 58 to expand to the expansion diameter when the sleeve 40 is inserted in the bore 22 of the rotation surface 16 and the shoulder inner face 52 abuts the rotation surface. In another example, a flinger structure or seal disk (not shown) may form the face of the rotation surface 16 and/or otherwise be disposed between the rotation surface and the shoulder inner face 52. In this configuration, the circumferential groove 54 of the sleeve outer surface 42 may be spaced from the inner face 52 of the shoulder 48 at a distance sufficient to enable the resilient ring outer diameter 58 to expand to the expansion diameter when the sleeve is inserted in the bore of the rotation surface and the shoulder inner face is adjacent the rotation surface and abutting the flinger structure or seal disk. In another example, as best shown in FIG. 5, the rotation surface 16 has an axial inner edge with an edge break, and the circumferential groove 54 of the sleeve outer surface 42 is spaced from the inner face 52 of the shoulder 48 at a distance sufficient to enable the resilient ring outer diameter 58 to expand to the expansion diameter adjacent the edge break when the sleeve 40 is inserted in the bore of the rotation surface and the shoulder inner face 52 is adjacent or abuts the rotation surface 16, as the case may be depending upon whether the rotation surface has an intermediate structure. In the last example, the circumferential groove 54 of the sleeve outer surface 42 is spaced from the inner face 52 of the shoulder 48 at a distance sufficient to enable the resilient ring 56 to clear the effective axial length of the rotation surface 16. Where no edge break condition is provided on the innermost axial edge of the rotation surface, the circumferential groove 54 of the sleeve outer surface 42 may be spaced from the inner face 52 of the shoulder 46 at a distance sufficient to enable the resilient ring 56 to clear the axial length of the rotation surface 16 and expand to the expansion diameter. In each of the examples above, the shoulder 48 may be pressed against the face of the rotation surface (or intermediate structure) to provide indication that the resilient ring has cleared the axial length of the rotation surface and has thus expanded to the resilient ring expansion diameter. The sleeve may also be dimensioned to allow some axial play between the shoulder and the face of the rotation surface (or intermediate structure) with the resilient ring cleared from the axial length of the rotation surface and at the resilient ring expansion diameter, for instance, to allow the sleeve to be grasped by the shoulder 48 and extracted from the bore 22 of the rotation surface. The resilient ring 56 may be configured to be sufficiently deformable such that the resilient ring outer diameter 58 may be compressed to an extraction diameter to enable the sleeve to be removed from the bore of the rotation surface the bearing with minimal force, as may be required during the assembly process. Accordingly, the resilient ring 56 may be configured so that the sleeve 40 is removably insertable in the bore of the rotation surface 10. The outer surface of the sleeve may have a close running fit (or with more accuracy a precision running fit) with the bore of the rotation surface thus allowing the sleeve to have a relatively small amount of clearance with the bore of the rotation surface with moderate requirements for accuracy. The outer surface of the sleeve may have a sliding fit (or with more accuracy a close sliding fit) with the bore of the rotation surface thus allowing the sleeve to have a relatively minimal amount of clearance with the bore of the rotation surface with higher requirements for accuracy. The resilient ring may deform to the compression and extraction diameter without otherwise changing the nature of the fit between the sleeve and the bore of the rotation surface.
Referring to FIG. 6, with the sleeve 40 installed in the respective bore 22 of the rotation surface 16, the sleeve forms a mounting surface for the rig fork or yoke 70 of the caster 10. In one example where first and second sleeves 40 are inserted in the respective bores 22 of the inner races 34 of the bearings 30 on axial opposite sides of the hub 14 of the wheel, the sleeves may abut against each other inside the hub of the wheel. The caster forks 70 may then be tightened against the sleeves 40 with an axle pin 80 and fastener 82. The caster forks 70 may bear against the shoulders 48 of the respective sleeves 40 which in turn loads the faces of the inner races 34 of the bearings 30. The wheel bearing 30 can then spin freely around the sleeves 40 without binding. Accordingly, each sleeve 40 is adapted and configured to receive an axle pin 80 of the caster to secure the respective fork 70 against the shoulder 48 of the sleeve 40.
In use, the sleeve 40 may be pushed into the bore 22 of the inner race 34 of the bearing 30 disposed in the hub 14 of the wheel 12. As the case may be, a second sleeve may be pushed into the bore of the inner race of a second bearing disposed on an axially opposite side of the hub of the wheel. The sleeve 40 may retained in the bore 22 of the inner race 34 of the bearing 30 by the resilient ring 56, e.g., an o-ring. The resilient ring 56 may be arranged on the sleeve 40 such that its outer diameter 58 compresses to a compression diameter as the sleeve is being inserted into and slides through the bore 22 of the inner race 34 of the bearing 30 disposed in the hub 14 of the wheel 12. The resilient ring 56 may be arranged on the sleeve 40 to return to its full or expansion diameter 58 once the resilient ring 58 passes through the bore 22 of the inner race 34 past the effective axial length of the bore of the inner race of the bearing. The result is that the sleeve 40 “snaps” into place within the bore 22 of the inner race 34 of the bearing 30 and is retained therein. This eliminates the need to use an external device, for instance, a tie or zip tie, to keep the sleeve 40 with the wheel 12 during the manufacturing and assembly process. The expansion of the resilient ring 56 is sufficient to retain the sleeve 40 in the bore 22 of inner race 34 of the bearing 30. However, the resilient ring 56 is sufficiently deformable to allow the resilient ring outer diameter 58 to compress to an extraction diameter to enable the sleeve 40 to be removed from the bore 22 of the inner race 34 of the bearing 30 with minimal force, as may be required during the assembly process.
Further embodiments can be envisioned by one of ordinary skill in the art after reading this disclosure. In other embodiments, combinations or sub-combinations of the above-disclosed invention can be advantageously made. The example arrangements of components are shown for purposes of illustration and it should be understood that combinations, additions, re-arrangements, and the like are contemplated in alternative embodiments of the present invention. Thus, various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims and that the invention is intended to cover all modifications and equivalents within the scope of the following claims.
Patent Application
20210188001
