Caster device for movably supporting a load

A caster device is disclosed for movably supporting a load. The caster device includes a wheel for supporting the load and a wheel support having a first and a second extremity. The first extremity of the wheel support supports the wheel for rotation of the wheel about an axis of rotation. The second extremity of the wheel support defines an aperture and the wheel support has a first surface and a second surface. A support stem has a first and a second end, the support stem extending through the aperture such that the aperture is disposed between the first and the second end of the support stem. The second end of the support stem is connected to the load for supporting the load. Also, a leaf spring is disposed between the aperture and the second end of the support stem such that the leaf spring resiliently contacts the load and cushions the load relative to the wheel.

FIELD OF THE INVENTION

The present invention relates to a caster device for movably supporting a load. More particularly, the present invention relates to a caster device having a leaf spring for resiliently supporting a load.

BACKGROUND OF THE INVENTION

Casters are used in many applications for movably supporting loads. One such application is a creeper that is used by auto mechanics or auto owners when inspecting the underside of an automobile. The creeper includes a padded base and a headrest carried by a caster supported frame. The arrangement is such that the mechanic supported on the base is able to slide under the automobile for inspecting and working on the automobile.

However, the creeper is often moved to different locations and there is a tendency for the user to drop the creeper onto the concrete floor of the workstation rather than carefully placing the creeper on the floor at the correct location. Consequently, after prolonged usage of the creeper, the shock of dropping the creeper onto the hard floor causes the casters thereof and/or the frame supported by the casters to be damaged, thereby usually resulting in the ball bearings of the casters to drop out of the casters.

SUMMARY OF THE INVENTION

The present invention overcomes the aforementioned problems and other problems by the provision of a leaf spring which resiliently contacts the frame or load to be supported and cushions the casters so that any shock on the caster is primarily absorbed by the leaf spring. More particularly, the present invention includes a caster device having a wheel for supporting the load and a wheel support for supporting the wheel for rotation about an axis of rotation. A support stem extends through an aperture in the wheel support and between the load and the wheel. A leaf spring is disposed between the load and the wheel, such that the leaf spring resiliently contacts the load and cushions the load relative to the wheel when a force is applied to the caster device, thereby inhibiting any damage to the caster device on account of the force applied thereto. According to one aspect of the invention, the leaf spring is adapted to provide a degree of lateral support to the load. Furthermore, the leaf spring improves the comfort and ride. In the case of a garage creeper, the user of the creeper is able to move on the creeper more smoothly than was the case with prior art arrangements.

Therefore, another feature of the present invention is the provision of a caster device for movably supporting a load that reduces the chances of a caster and/or frame supported by the caster from being damaged after repeated use.

A further feature of the present invention is the provision of a caster device which provides a degree of lateral support to the load carried by the caster.

Yet another feature of the present invention is the provision of a caster device for movably supporting a load that provides smoother movement of the load supported by the caster.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1is a side elevational view partially in section of a caster device generally designated10according to the present invention for movably supporting a load L. As shown inFIG. 1, the caster device10includes a wheel12for supporting the load L and a wheel support14having a first and a second extremity16and18respectively. The first extremity16of the wheel support14supports the wheel12for rotation of the wheel12about an axis of rotation20. The second extremity18of the wheel support14defines an aperture22and the wheel support14has a first surface24and a second surface26. A support stem28has a first and a second end30and32respectively, the support stem28extending through the aperture22such that the aperture22is disposed between the first and the second ends30and32respectively of the support stem28. The second end32of the support stem28is connected to a load member L for supporting the load L. Also, spring member, preferably a leaf spring, generally designated34is disposed between the aperture22and the second end32of the support stem28such that the leaf spring34resiliently contacts the load L and cushions the load L relative to the wheel12.

FIG. 2is a sectional view taken on the line2—2of FIG.1. As shown inFIG. 2, the wheel12is a caster having a first and a second side36and38respectively, the caster12defining a bore40which extends between the first and the second sides36and38respectively of the caster12. An axle42has a first and a second termination44and46respectively, the axle42extending through the bore40such that the caster12is rotatably supported by the axle42for rotation thereof about the axis of rotation20.

Furthermore, the wheel support14is a horn, the first extremity16of the wheel support14supporting the first and a second termination44and46respectively of the axle42.

Additionally, the first surface24of the second extremity18of the wheel support14defines an annular depression48, the depression48being disposed concentrically relative to the aperture22. A bearing race50is secured to the first end30of the support stem28, the bearing race50being disposed concentrically relative to the depression48. A plurality of bearings52and54are disposed between the bearing race50and the depression48so that the bearings52and54are captured between the depression48and the bearing race50, the depression48being disposed between the bearing race50and the second end32of the support stem28. More specifically, the bearings52and54are ball bearings.

Moreover, the second surface26of the second extremity18of the wheel support14defines a further annular depression56, the further annular depression56being disposed concentrically relative to the aperture22. The further annular depression56has a greater diameter D than a diameter d of the annular depression48.

The caster device10also includes a further plurality of bearings58and60that are captured between the further annular depression56and the leaf spring34. The further plurality of bearings58and60are preferably further ball bearings.

Also, the support stem28includes a head62which is disposed adjacent to the first end30of the support stem28for preventing axial movement of the wheel support14relative to the support stem28.

Additionally, the support stem28includes a radially extending flange64which is disposed between the first and the second ends30and32respectively of the support stem28, the wheel support14and the leaf spring34being disposed between the head62and the flange64of the support stem28.

The leaf spring34has a first and a second face66and68respectively, the first face66of the leaf spring34defining an annular recess70which cooperates with the further annular depression56. The arrangement is such that the further plurality of bearings58and60are captured between the further annular depression56and the annular recess70of the leaf spring34.

Moreover, the leaf spring34defines a hole72for the reception therethrough of the support stem28such that the leaf spring34is anchored to the support stem28.

Furthermore, as shown inFIG. 1, the leaf spring34includes a first arm74which extends away from the hole72and a second arm76which extends away from the first arm74and the hole72. The arms74and76respectively cooperate with and resiliently support the load.

More specifically, as shown inFIG. 2, the first arm74includes a first wing78and a second wing80which is disposed spaced and parallel relative to the first wing78.

FIG. 3is a sectional view taken on the line3—3of FIG.1. As shown inFIG. 3, the second arm76(FIG. 1) includes a first wall82and a second wall84which is disposed spaced and parallel relative to the first wall82. The wings78and80and the walls82and84cooperate with the load L in order to provide lateral support for the load L. The wings78and80and walls82and84are adapted to also stabilize the leaf spring34with respect to the load member L. Moreover, the wings78and80and walls82and84are configured such that when a force or load is applied to the caster device10to activate the leaf spring34, the tabs or wings78and80and walls82and84do not completely disengage the load member L. Thus, It should be noted that although not shown inFIGS. 2 and 3, the tab members78,80,82and84are preferably engageable with the load member L.

FIG. 4is a top plan view of the leaf spring34shown inFIGS. 1-3. As shown inFIG. 4, the leaf spring34includes arms74and76and wings78and80and walls82and84. Also, as shown inFIG. 4, the leaf spring34is preferably fabricated from a metallic spring sheet pressing. Although, the spring member34could be made of other suitable resilient materials.

FIG. 5is a sectional view taken on the line5—5of FIG.4. As shown inFIG. 5, it can be appreciated that the wing80and the wall84provide a certain amount of lateral stability to the load L supported by the caster device10.

FIG. 6is a sectional view taken on the line6—6of FIG.4. As shown inFIG. 6, the wings78and80and arm74define a generally U-shaped configuration.

In operation of the caster device10, the support stem28is inserted through the hole72of the leaf spring34and the ball bearings58and60are placed within the annular recess70. The support stem28is inserted through aperture22of the wheel support14so that the further annular depression captures the bearings58and60. The plurality of smaller bearings52and54are located within the annular depression48and the bearing race50is placed over the first end30of the support stem so that the bearings52and54are captured between the bearing race50and the annular depression48. The first end30of the support stem28is then deformed or otherwise configured to provide the head62for locking the various components together. The second end32of the support stem is inserted within a complementary cavity86defined by the load L so that the load L is supported by the caster device10with the arms, wings and walls of the leaf spring34resiliently supporting the load L on the caster device. As can be observed inFIG. 1, a gap is provided between the leaf spring34and load member L, so as to desirably accommodate the movement of the spring34when subjected to a load.

The present invention provides a unique arrangement for resiliently supporting a load on a caster thereby prolonging the life of the caster.