Vertically adjustable caster wheel

A caster wheel assembly for an industrial vehicle comprising a lower housing connected to a wheel, an upper housing connectable to the industrial vehicle, and an inner alignment post disposed within the lower and upper housings. The upper housing is at least partially disposed within the lower housing. Rotation of the inner alignment post relative to the upper housing adjusts vertical displacement of the lower housing relative to the upper housing.

TECHNICAL FIELD

This disclosure relates to caster wheels, and more particularly to a caster wheel that is vertically adjustable from a top of the caster wheel.

BACKGROUND

Heavy-duty caster wheels are frequently used to support relatively heavy loads transported by small forklift trucks, material handling carts, and the like. To adjust the height of the caster wheel, many designs require the caster wheel to be partially or entirely disassembled. Other caster wheel designs provide angular or height adjustment by accessing fasteners and/or springs from the bottom or sides of the caster wheel. In either instance, adjusting the height of the caster wheel may be a timely and inconvenient task. Therefore, a need exists for a quick and simple method for providing vertical adjustment of the caster wheel.

SUMMARY

In one aspect of the present disclosure, a caster wheel assembly is described for use with an industrial vehicle, for example. The caster wheel assembly includes a lower housing connected to a wheel, an upper housing connectable to the industrial vehicle, and an inner alignment post disposed within the lower and upper housings. The upper housing is at least partially disposed within the lower housing. Rotation of the inner alignment post relative to the upper housing adjusts vertical displacement of the lower housing relative to the upper housing.

In another aspect of the present disclosure, an adjustable caster wheel assembly is described that includes a lower housing, an upper housing positioned with the lower housing and including a threaded portion, and an alignment post rotatably positioned within the upper housing. The alignment post includes a threaded portion that is configured and dimensioned for engagement with the threaded portion of the upper housing such that rotation of the alignment post in a first direction causes separation of the upper and lower housings to increase a height of the caster wheel assembly and rotation of the alignment post in a second direction causes approximation of the upper and lower housings to decrease a height of the caster wheel assembly.

In certain embodiments, the lower housing, the upper housing, and the alignment post may be positioned in concentric relation.

In certain embodiments, the alignment post may be configured, dimensioned, and positioned such that the alignment post is vertically accessible from above the upper housing.

In certain embodiments, the alignment post may include a first section including the threaded portion and a second, non-threaded section spaced longitudinally from the first section.

In certain embodiments, the alignment post may further include a shoulder positioned between the first and second sections.

In certain embodiments, the first section of the alignment post may define a first diameter, the second section of the alignment post may define a second diameter, and the shoulder may define a third diameter. In such embodiments, the third diameter may be greater than the first and second diameters.

In certain embodiments, the caster wheel assembly may further include a swivel bearing positioned within the lower housing. In such embodiments, the swivel bearing may include a bore that is configured and dimensioned to receive the alignment post.

In certain embodiments, the second section of the alignment post may be configured and dimensioned for insertion into the bore of the swivel bearing, for example, in a friction fit.

In certain embodiments, the caster wheel assembly may further include a rotation restriction member that is configured and dimensioned for engagement with the alignment post to restrict rotation of the alignment post.

In certain embodiments, the rotation restriction member may include an engagement structure that is configured and dimensioned for engagement with a corresponding receiving structure formed on the alignment post. For example, in certain embodiments, the engagement structure may include a pair of legs, and the receiving structure may include a pair of longitudinal cutouts that are configured and dimensioned to receive the legs.

In certain embodiments, the upper housing may include opposing ends each defining openings that are approximately equivalent in diameter and a bore extending between the opposing ends. In such embodiments, the bore may include a center region with a stepped configuration defining a diameter less than the diameters defined by the openings at the opposing ends of the upper housing whereby the center region of the bore includes an internal shoulder.

In certain embodiments, the center region of the bore may include a plurality of internal shoulders defining progressively smaller diameters.

In certain embodiments, the caster wheel assembly may further include a stop member to limit vertical adjustment of the caster assembly.

In certain embodiments, the stop member may be configured, dimensioned, and positioned for engagement with the lower housing.

In another aspect of the present disclosure, an adjustable caster wheel assembly is described that includes first and second housings that are configured and dimensioned for relative displacement along a vertical axis, and an alignment post that is positioned concentrically with respect to the first and second housings. The alignment post is configured and dimensioned for rotation to cause relative displacement between the first and second housings along the vertical axis to vary a height of the caster wheel assembly. The alignment post is also configured, dimensioned, and positioned such that the alignment post is vertically accessible from above the first and second housings.

In certain embodiments, the alignment post may include a threaded section configured and dimensioned for engagement with a corresponding threaded section in the first housing such that rotation of the alignment post in a first direction causes separation of the first and second housings and rotation of the alignment post in a second direction causes approximation of the first and second housings.

In certain embodiments, the caster wheel assembly may further include a rotation restriction member that is configured and dimensioned for engagement with the alignment post to restrict rotation of the alignment post.

In another aspect of the present disclosure, a method is disclosed for adjusting the height of a caster wheel assembly. The method includes vertically accessing an alignment post from above the caster wheel assembly and rotating the alignment post in relation to first and second housings of the caster wheel assembly to cause relative displacement of the first and second housings along a vertical axis.

DETAILED DESCRIPTION

FIGS. 1-4illustrate a caster wheel assembly10that can be vertically adjusted from the top of the caster wheel assembly10. As a result, the vertical height of the caster wheel assembly10can be increased or decreased while the caster wheel assembly10is attached to an industrial vehicle (not shown), such as a forklift truck. Consequently, the vertical height of the caster wheel assembly10can be adjusted by accessing the caster wheel assembly10through an aperture in the floor of the industrial vehicle, thereby avoiding the need to disassemble the caster wheel assembly10or accessing the caster wheel assembly10from underneath the industrial vehicle.

The caster wheel assembly10can include a mounting plate12, an upper housing14, a lower housing16, an axle housing18, an axle20, an inner alignment post22, a stop block24, and one or more wheels26. In order to connect the caster wheel assembly10to the industrial vehicle, the mounting plate12, as illustrated in detail inFIGS. 5-6, can be made from any suitable material, such as steel. As shown, the mounting plate12has a substantially rectangular cuboid configuration, although other configurations are possible. To assist with mounting the caster wheel assembly10to the industrial vehicle, the mounting plate12can be provided with first apertures28that extend through a top face30and a bottom face32of the mounting plate12. Each first aperture28can be capable of receiving a conventional fastener (not shown), such as a screw, that extends through the first aperture28and is received by a corresponding aperture in a frame of the industrial vehicle. As shown, there are four first apertures28that are positioned adjacent to four corners of the mounting plate12. The number and positioning of the first apertures28can vary depending on the implementation.

To limit the amount of vertical adjustment provided by the caster wheel assembly10, the stop block24is mounted to the mounting plate12through two second apertures34and/or a third aperture36that extend through the top face30and the bottom face32of the mounting plate12, wherein the third aperture36is between the second apertures34. The second apertures34are each capable of receiving a roll pin38(shown inFIG. 1), and the third aperture36can receive a conventional fastener, such as a screw40(shown inFIG. 1). The third aperture36can have a diameter larger than diameters of the second apertures34.

To assist with connecting the upper housing14to the mounting plate12, the mounting plate12can be provided with a fourth aperture42that is centrally located and has a diameter that is slightly larger than an outer diameter of a center region64of the upper housing14. The upper housing14and the mounting plate12can be welded together to form an integral unit. As shown inFIG. 6, the fourth aperture42extends through the mounting plate12from the top face30to the bottom face32. As shown, the diameter of the fourth aperture42is substantially constant adjacent to the top face30of the mounting plate12and tapers inward toward the bottom face32of the mounting plate12, forming a shoulder44where the diameter of the fourth aperture42tapers inward. The second apertures34and the third aperture36can be linearly aligned near the fourth aperture42so that the stop block24can interact with the lower housing16, as will be explained.

The upper housing14, shown inFIGS. 7-8, is matingly received by the fourth aperture42in the mounting plate12, wherein the outer diameter of the upper housing14can be larger at the first end48of the upper housing14so that a first chamfer58can be seated against the top face30of the mounting plate12when the upper housing14is connected to the mounting plate12via the fourth aperture42. A second chamfer60can be formed at the second end50of the upper housing14where the outer diameter of the upper housing14tapers further. The outer diameter of the upper housing14can remain substantially constant between the first chamfer58and the second chamfer60. The upper housing14can have a substantially tubular configuration with a bore46extending through the upper housing14that is coaxial with the fourth aperture42of the mounting plate12. The upper housing14can be fabricated from any suitable material, such as steel.

To prevent undesired vertical adjustment of the caster wheel assembly10through rotation of the inner alignment post22, the bore46extends between a first end48and a second end50of the upper housing14. As shown, the diameter of the bore46is stepped so that the first end48and the second end50of the upper housing14are substantially the same, and a center region62of the bore46is smaller than the first end48and the second end50, defining a first shoulder52and a second shoulder54. The center region62can be provided with threading. Cutouts56can extend into the upper housing14approximately half of the distance between the first shoulder52and the second shoulder54. The cutouts56can have a substantially arcuate or C-shape cross-sectional configuration that is complementary to legs144of a rotation restriction member142(shown inFIG. 1).

To allow vertical displacement of the lower housing16relative to the upper housing14, the upper housing14can be partially nested within a bore66of the lower housing16. The lower housing16is illustrated in detail inFIG. 9and can be made from any suitable material, such as steel. The lower housing16can have a substantially tubular configuration with the bore66extending through the lower housing16from a first end68to a second end70. The bore66can be coaxially aligned with the bore46of the upper housing14, and the diameter of the bore66may be stepped between the first end68and the second end70of the lower housing16. As shown, the diameter of the bore66is stepped to define shoulders72,74,76,78,80,82that house a snap ring84, a wear ring86, a flexible seal88, and a swivel bearing90(shown inFIG. 1) to allow for rotation of the lower housing16relative to the upper housing14.

The stepped diameter of the bore66of the lower housing16forms a first shoulder72near the first end68of the lower housing16. The diameter of the bore66between the first end68and the first shoulder72can be sized to house the flexible seal88. A second shoulder74and a corresponding third shoulder76are formed a short distance away from the first shoulder72. The diameter of the bore66between the second shoulder74and the third shoulder76can be sized to house the wear ring86. A fourth shoulder78and a corresponding fifth shoulder80can also be formed between the first end68and the second end70of the lower housing16. The diameter of the bore66between the fourth shoulder78and the fifth shoulder80can be sized to house the snap ring84. The diameter of the bore66between the first shoulder72and the second shoulder74and the diameter of the bore66between the second shoulder74and the third shoulder76can be substantially the same and can be sized to be slightly larger than the outer diameter of a center region64of the upper housing14. A sixth tapered shoulder82can be formed near the second end70of the lower housing16. The diameter of the bore66between the fifth shoulder80and the sixth shoulder82can be sized to house the swivel bearing90.

The snap ring84, the wear ring86, and the flexible seal88can be made from any suitable material. For example, the snap ring84could be made from a metal, such as steel, and the wear ring86and the flexible seal88could be made from nylon or rubber. As shown inFIG. 1, the snap ring84can have a substantially C-shaped configuration that is slightly larger than the diameter of the bore66of the lower housing16between the first end68and the first shoulder72of the lower housing16. As a result, ends108of the snap ring84can be close to touching or touching when the snap ring84is disposed within the lower housing16. The wear ring86can have a substantially ring-like configuration with the exception of a cut110that forms ends to assist with inserting the wear ring86into the lower housing16between the second shoulder74and the third shoulder76. The flexible seal88and the swivel bearing90can have substantially ring-like configurations. The swivel bearing90can be fabricated from any suitable material, such as steel, and have a thickness that is greater than a thickness of the flexible seal88. The swivel bearing90can be provided with a lubricant that the flexible seal88assists with containing.

The lower housing16can further include a lip92adjacent to the first end68, and a recess94formed on the second end70. The lip92can extend substantially perpendicular from an outer surface96of the lower housing16to interact with the stop block24. The recess94can have a substantially arcuate configuration, which allows the axle housing18to be mounted and/or welded flush against the lower housing16.

The axle housing18is illustrated in detail inFIGS. 10-11and can be made from any suitable material, such as steel. The axle housing18can have a substantially tubular configuration with a bore98extending through the axle housing18from a first end100to a second end102. The axle housing18can have a cutout104that allows the axle housing18to be mounted and/or welded flush against the lower housing16. As shown, the cutout104has a generally triangular configuration with two sides having a substantially linear configuration and a third side having a generally arcuate configuration. The axle housing18can also be provided with an aperture106that extends through the axle housing18substantially perpendicular to the bore98of the axle housing18and is in communication with the bore98of the axle housing18. The aperture106can be spaced approximately half way between the first end100and the second end102of the axle housing18.

To provide for rotation of the wheels26, the axle20is illustrated in detail inFIG. 12and can be fabricated from any suitable material, such as steel. The axle20can be substantially solid with threading on a first end112and a second end114, which allows lock nuts116to be secured to the first and second ends112,114of the axle20. A center portion118of the axle20can be disposed or press fit within the bore98of the axle housing18and is sized to accommodate such. The center portion118of the axle20can be provided with an aperture120capable of receiving a drive pin122(shown inFIG. 1). When the center portion118of the axle20is disposed within the bore98of the axle housing18, the aperture120of the axle20aligns with the aperture106so that the drive pin122can extend through the axle20and the axle housing18to prevent rotation of the axle20relative to the axle housing18.

Two intermediary portions124of the axle20can be disposed between the center portion118and the first and second ends112,114, respectively. The intermediary portions124can have substantially the same diameter, which can be less than the diameter of the center portion118and greater than the diameter of the first and second ends112,114. When the center portion118of the axle20is disposed within the bore98of the axle housing18, wheel bearings126can be seated against shoulders128formed between the center portion118and the first and second ends112,114of the axle20, followed by the wheels26, spacer tubes130, wheel bearings132, washers134, and the lock nuts116(shown inFIG. 1). The wheel bearings126,132can be provided with a lubricant.

To facilitate vertical adjustment of the caster wheel assembly10, the inner alignment post22is disposed within the upper housing14and the lower housing16so that the inner alignment post22, the upper housing14, and the lower housing16are concentric. The inner alignment post22is illustrated in detail inFIGS. 13-14and can be fabricated from any suitable material, such as steel. The inner alignment post22can have a generally cylindrical configuration with a threaded first portion140that is configured for threadably engaging the threaded center region62of the bore46of the upper housing14. The threaded first portion140can be provided with cutouts146in one end of the inner alignment post22that can have a substantially arcuate or C-shape cross-sectional configuration that is complementary to the legs144of the rotation restriction member142. As shown, there are two cutouts146that are opposite one another and can be aligned with two of the four cutouts56in the bore46of the upper housing14. A counterbored aperture148capable of receiving a conventional fastener (not shown) can extend into the inner alignment post22from a first end150.

A shoulder158formed on the inner alignment post22separates the threaded first portion140from a second portion156of the inner alignment post22. A chamfer or recess160can be formed between the threaded first portion140and the shoulder158. The shoulder158can have a transverse cross-sectional dimension (e.g., a diameter) greater than a transverse cross-sectional dimension (e.g., a diameter) of the threaded first portion140and a transverse cross-sectional dimension (e.g., a diameter) of the second portion156. The second portion156of the inner alignment post22can be configured so that the second portion156can be secured within a bore162of the swivel bearing90(shown inFIG. 1) via a friction fit with the shoulder158of the inner alignment post22resting on top of the swivel bearing90. An aperture154coaxially aligned with the counterbored aperture148can extend into the second portion156of the inner alignment post22from a second end152of the inner alignment post22. The aperture154is capable of receiving a conventional fastener, such as a screw138(shown inFIG. 1). A washer136(shown inFIG. 1) can also be used at the second end152of the inner alignment post22with the screw138.

To prevent the lower housing16from separating from the upper housing14through excessive rotation of the inner alignment post22, the stop block24can be mounted to the mounting plate12adjacent to the upper housing14. The stop block24is illustrated in detail inFIGS. 15-16and can be fabricated from any suitable material, such as steel or a polymer. The stop block24can have a generally rectangular cuboid configuration with a generally arcuate configuration on a first side164, which allows the stop block24to be mounted flush against the upper housing14. A counterbore170can extend through the stop block24from a bottom end168to a top end166, and apertures172can extend into the stop block24from the top end166. When the stop block24is positioned adjacent to the upper housing14, the apertures172of the stop block24align with the second apertures34of the mounting plate12to allow insertion of the roll pins38, and the counterbore170of the stop block24aligns with the third aperture36of the mounting plate12to allow insertion of the screw40. A lip174can protrude from the first side164of the stop block24near the bottom end168that can engage the lip92of the lower housing16when the caster wheel assembly10is at its greatest vertical height.

Once at a desired vertical height, the rotation restriction member142prevents rotation of the inner alignment post22. As shown inFIG. 1, the rotation restriction member142is comprised of the legs144and a base176that is substantially perpendicular to the legs144. The legs144can be mounted or welded to the base176. The base176can have a substantially disc-like configuration with an aperture178extending through a center of the base176that is capable of receiving a conventional fastener (not shown). As shown, there are two legs144that are linearly aligned with the aperture178. When the rotation restriction member142is disposed within the upper housing14, the base176is seated against the first shoulder52formed in the bore46with the legs144positioned within the cutouts56of the bore46and cutouts146of the inner alignment post22.

To adjust the vertical height of the caster wheel assembly10, the rotation restriction member142is removed from the upper housing14. If the caster wheel assembly10is attached to the industrial vehicle, the industrial vehicle can provide an aperture (not shown) in the floor of the industrial vehicle that allows access to the rotation restriction member142from above, thereby obviating any need for disassembly of the caster wheel assembly10and increasing the ease of operation in relation to known systems. Once the rotation restriction member142has been removed, the inner alignment post22can be rotated. For example, in one embodiment, it is envisioned that rotation of the inner alignment post22may be effected via rotation of the fastener inserted into the aperture148(FIG. 13).

Because of the complementary threading in the center region62of the bore46of the upper housing14and the threaded first portion140of the inner alignment post22, rotation in a first direction causes the vertical height of the caster wheel assembly10to increase and rotation in a second direction opposite the first direction causes the vertical height of the caster wheel assembly10to decrease. The lip174on the stop block24and the lip92on the lower housing16prevent the inner alignment post22from being rotated so far in the first direction that the lower housing16separates from the upper housing14.

Once the desired vertical height of the caster wheel assembly10has been obtained, the rotation restriction member142is replaced so that the base176is seated against the first shoulder52formed in the bore46and the legs144positioned within the cutouts56of the bore46and cutouts146of the inner alignment post22. A conventional fastener, such as a screw, can then be inserted into the aperture178of the rotation restriction member142and the counterbored aperture148of the inner alignment post22to secure the rotation restriction member142to the inner alignment post22.

In the preceding description, reference may be made to the spatial relationship between the various structures illustrated in the accompanying drawings, and to the spatial orientation of the structures. However, as will be recognized by those skilled in the art after a complete reading of this disclosure, the structures described herein may be positioned and oriented in any manner suitable for their intended purpose. Thus, the use of terms such as “above,” “below,” “upper,” “lower,” “inner,” “outer,” “upward,” “downward,” “inward,” “outward,” etc., should be understood to describe a relative relationship between structures and/or a spatial orientation of the structures. Those skilled in the art will also recognize that the use of such terms may be provided in the context of the illustrations provided by the corresponding figure(s).

Additionally, terms such as “approximately,” “generally,” “substantially,” and the like should be understood to allow for variations in any numerical range or concept with which they are associated. For example, it is intended that the use of terms such as “approximately” and “generally” should be understood to encompass variations on the order of 25%, or to allow for manufacturing tolerances and/or deviations in design.