Patent Application
20080148514
This invention relates generally to casters for support of an object intended to roll along a floor surface. A variety of casters for such purposes is known. Many swivel freely to facilitate rolling an object in whatever direction the object is pushed or pulled. Some of them have a swivel locking feature. Some have a brake to prevent the caster from rolling. Some have a combination of swivel and lock.
A problem frequently encountered with swivel casters is a fluttering characteristic, particularly when the object supported on them is pushed or pulled and one or more of the casters encounter irregular surfaces. Fluttering can also occur when a frame which has four swivel casters on, has been bent or otherwise damaged so that one caster is not continuously and fully-engaged with the surface on which the object is being moved.
Another problem with swiveling casters is that, where the floor on which the casters are rolling is sloped to the side of a direction on which the cart or other object supported by the casters is being pushed or pulled, there is a tendency of the object to drift sideways down the slope and become difficult to control.
Another problem often associated with casters, particularly when exposed to or operating in an environment which is dusty or in which the floor surface is dirty, or wet with water or other fluids, is the accumulation of dirt on the caster wheel, axle, or swivel assembly, or all of these aspects. In addition to interfering with performance of such casters, such environments tend to deteriorate the appearance of the caster.
It is also possible for there to be instances in which a object supported by casters is adapted for operation by remote control or otherwise in a circumstance where the performance of a caster or casters is not readily detectable. In some such instances, a caster wheel or swivel or both may become jammed or impeded by dirt or in some other manner.
In view of the foregoing, and notwithstanding the many types of casters that have been developed in the prior art, there remains a need for a caster assembly which better addresses one or more of the foregoing problems.
A swivel caster assembly has an adapter for fixing to an object to be supported by the caster assembly for rolling the object along a floor in a direction. A wheel mounted horn is swivel mounted to the adapter. A first detent member is fixed to the adapter and has a detent recess. A second detent member is movably mounted to the horn and co-operable with the recess in the first detent member as the object is rolled along a floor to minimize flutter as the object moves along. The detent members are concealed under a top portion of the horn.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.
Referring now to the drawings in detail, and
Referring now to
The horn and bearing assembly are connected together by a kingpin 31, the upper end of which, prior to being staked, is passed through center holes in the lower retainer 14, the lower race 22, the upper retainer 30, the dust cap 16 and the mounting plate 18 to which the upper-end of the kingpin is staked at 33. Consequently, the mounting plate 18, kingpin 31, dust cap 16, upper retainer 30, lower race 22, and lower retainer 14 become fixed together when the king pin is staked to plate 18. They are fixed to the object 21 by screws 19 or the like through the four holes (
While the caster horn with wheel can freely swivel about the axis 32, the swiveling is controllable at two locations 180 degrees apart. For that purpose, the lower retainer 14, as best shown in
This detent arrangement being at opposite ends of line 25 through swivel axis 32, dictates that once the caster assembly is oriented, with the horn in one or the other of the two detented orientations relative to the mounting plate, the caster will remain in that orientation and acts like a rigid caster when moved forward or backward in straight-line movement. When sufficient side forces are applied, the plunger end can be forced out of the notch and down one or the other of the ramps adjoining the notch so the horn with wheel can swivel until returning to either an original forward position in
It is important that the mounting of the caster assembly to the object 21 being supported by it, makes the line 25 parallel to the intended rolling direction of the object 21. For example, the long axis of plate 18 is parallel to line 25. An adapter mounting the caster assembly to the object 21 could be shaped different from plate 18, but should align the detent line 25 with intended direction of forward or backward rolling of the object 21.
In either forward or backward position of the caster, because of the compact nature of the caster, the whole caster assembly, including the wheel, is within the downward projection (the dashed line 46 in
As noted above, the threaded cylinder 39 with internal plunger and spring are attached underneath the trailing side of the top portion of the caster horn. The detent notches are within the vertical downward projection of the lower retainer 14. Therefore they are not readily visible and do not cause interference with anything outside the swivel radius of the caster assembly. In addition, because the detent apparatus is totally under the top portion of the caster horn and has a minimal number of parts, simplicity and cleanliness are promoted. There is no interference with the caster mounting or with the grease fitting which is protected and hidden under the mounting plate. The combination offers simplicity of function while maintaining the neat appearance of the caster assembly. Moreover, it is well adapted to wash-down operations on the object to which such caster assemblies may be mounted. The detent adjustment feature makes the assembly easily adjustable for various applications and operating conditions.
The horn is shown in the illustrations herein, as having two spaced leg portions, with a top portion offset toward the center of the space at the top of the leg portions, forming a bridge connecting the leg portions. The invention can be practiced with a single leg portion supported by the wheel, and the top portion cantilevered from the leg portion and still provide bearing race retainers and swivel axis and detent apparatus coverage as in the illustrations herein. Therefore, while an embodiment of the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that all changes and modifications that come within the spirit of the invention are desired to be protected.
