Bearings – Linear bearing – Roller bearing
Reexamination Certificate
1999-01-30
2001-06-19
Footland, Lenard A. (Department: 3682)
Bearings
Linear bearing
Roller bearing
C384S565000, C384S572000, C384S577000
Reexamination Certificate
active
06247847
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to cages for rotatably retaining bearings, aligning the bearings, and for separating them from one another.
BACKGROUND OF THE INVENTION
Bearing retaining cages retain bearings such that the bearings are held in place but are allowed to freely rotate. Generally, the cages are circular or linear. In this manner a bearing cage may be used to hold bearings in alignment with one another and to keep the bearings separate from one another so that they do not rub against one another. The bearings may be contained between an inner and outer race to facilitate relative movement of one about the other. Bearing cages may also include a protruding member for alignment in a slot along a race to align the bearings and to limit their movement in a direction perpendicular to the slot.
Examples of bearing retaining cages include those as disclosed in U.S. Pat. Nos. 1,018,324 to Kempster; 2,016,526 to Tyson; 3,980,359 to Weatherbee; and 5,154,401 to Schramm. The bearing cages as disclosed in these patents and as otherwise known in the art, however, have in common heretofor unresolved problems.
Such bearing retaining cages may be difficult to install, particularly if they are circular and include a protruding member for insertion into a slot on one of the inner or outer races. Such retaining cages are typically snap fit into place. Snap fitting of the cages, however, can lead to failure of the retaining cage or of the protruding member.
Also, as many different bearing applications exist, it is required to manufacture bearing retaining cages of many different sizes. For instance, a given diameter race will require a retaining cage of that diameter. Further, for applications having a race that is not circular shaped but is instead oval or otherwise features an oddly shaped race, bearing retaining cages as presently known may not be appropriate.
There is therefor an unresolved need in industry for an improved bearing retaining cage.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a bearing retaining cage that is flexible.
It is a further object of the invention to provide a bearing cage assembly having a flexible cage.
SUMMARY OF THE INVENTION
The present invention comprises a flexible bearing retaining cage for rotatably retaining bearings. The cage generally comprises a flexible spine having retaining means for rotatably retaining bearings. The present invention further comprises a flexible bearing retaining cage assembly generally having a flexible spine with bearing retaining means, and bearings rotatably retained by said means.
The flexible retaining cage of the invention has a spine preferably comprised of a resilient, deformable plastic. The flexible cage retaining means preferably comprise a plurality of notches spaced along the spine for snap fitting a plurality of roller bearings, or a plurality of annular rings for snap fitting a plurality of ball bearings. One each of the plurality of bearings is snap fit into each respective notch or ring. The bearings are held by the retaining means so as to allow for relatively low resistance rotation of the bearings. The bearings may be comprised of any suitable material, and are preferably comprised of a relatively hard, durable plastic. The flexible bearing retaining cage of the invention comprises the flexible spine with bearings snap fit into place. Snap fitting of the bearings provides for easy installation of bearings to the cage. Bearings that are snap fit in a cage also greatly improves the ease of installation of the bearings into a race as the snap fit assembly eliminates the need to handle and install each bearing individually. This is of particular advantage for applications using small bearings that may be difficult to handle.
The flexible bearing retaining cage and cage assembly of the invention provide several advantages over the cages and assemblies of the prior art. Because the cage is flexible, it may be configured in a variety of different shapes, including, but not limited to, a circle, an oval, or a straight line. Prior to the present invention, races having shapes other than circular could not use bearing retaining cages.
The spine of the cage of the present invention may protrude beyond the retained bearing surfaces so that it may be movably held in a groove on an inner or outer race. The spine movably held in the groove thereby helps to align the bearings, and to prevent bearing movement in a direction perpendicular to the direction of the groove.
Further, because it is flexible, the bearing retaining cage of the invention may be manufactured in generally bulk quantities, and then cut to a desired length to fit a race of a given size. For example, a circular race having a 10 inch circumference can be accommodated by the cage of the invention by cutting a 10 inch length from a bulk quantity. Likewise, a circular race having a 20 inch circumference may be accommodated by the cage of the invention by cutting a 20 inch length from the bulk quantity. Also, the cage of the invention may be used in applications using a linear race. In this manner, advantage may be taken of economies of scale available through manufacturing bulk quantities of the cage. Great savings will be realized by eliminating the need to manufacture and stock a number of differently sized and shaped cages.
Also, the flexible cage of the invention provides for easier installation to a race than cages of the prior art. Using the cage of the invention, the flexible spine with bearings snap fit into place may be easily fed into or wrapped about a race where it will bend to follow the shape of the race. When a sufficient length of the cage has been fed or into or wrapped about the race, it can be cut. This eliminates the need to snap fit a cage and the frequent breakage that accompanied such snap fitting.
The above brief description sets forth rather broadly the more important features and advantages of the present disclosure so that the detailed description that follows may be better understood, and so that the present contributions to the art may be better appreciated. There are, of course, additional features of the disclosure that will be described hereinafter which will form the subject matter of the claims appended hereto. In this respect, before explaining the embodiment of the disclosure in detail, it is to be understood that the disclosure is not limited in its application to the details of the construction and the arrangements set forth in the following description or illustrated in the drawings. The present invention is capable of other embodiments and of being practiced and carried out in various ways, as will be appreciated by those skilled in the art. Also, it is to be understood that the phraseology and terminology employed herein are for description and not limitation.
REFERENCES:
patent: 1018324 (1912-02-01), Kempster
patent: 1080288 (1913-12-01), Lockwood
patent: 1173719 (1916-02-01), Hirth
patent: 2016526 (1935-10-01), Tyson
patent: 2334227 (1943-11-01), Stallman
patent: 2365154 (1944-12-01), Storz
patent: 3344682 (1967-10-01), Bratz
patent: 3399008 (1968-08-01), Farrell
patent: 3806213 (1974-04-01), Nagai
patent: 3920292 (1975-11-01), Haussels
patent: 3980359 (1976-09-01), Wetherbee, Jr.
patent: 4391476 (1983-07-01), Negele et al.
patent: 4541819 (1985-09-01), Mazziotti
patent: 4557614 (1985-12-01), Knappe
patent: 4837909 (1989-06-01), Schalk
patent: 4915515 (1990-04-01), Rohrer et al.
patent: 5001831 (1991-03-01), Vinciguerra et al.
patent: 5154401 (1992-10-01), Schramm
patent: 5156378 (1992-10-01), Harken et al.
patent: 5284395 (1994-02-01), Sternberger
Footland Lenard A.
Harken, Inc.
Pyle & Piontek
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