US 3699609 A
An improved caster for the bottom of a stool or other furniture item, the caster comprising a casing containing a compression spring which bears adjustably against a spherical steel ball engaging a floor or supporting surface.
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Description (OCR text may contain errors)
United States Patent Spatz SPRING LOADED CASTER FOR SHOP TOOLS, BAR STOOLS AND THE LIKE Inventor: William L. Spatz, Route 2, PO. Box
194-A, Montevallo, Ala. 35115 Filed: April 12, 1971 Appl. No.: 133,245
Related us. Application Data Substitute for Ser. No. 801,982, Feb. 25, 1969, abandoned.
US. Cl. ..l6/44 Int. Cl. ..A47b 91/00 Field of Search .....l6/44, 26, 19; 248/l88.9, 21,
[ 1 Oct. 24, 1972  References Cited UNITED STATES PATENTS 2,176,551 10/1939 Solem ..16/44 7/1963 Rabelos "16/44 Primary Examiner-Bobby R. Gay Assistant Examiner-Doris L. Troutman  ABSTRACT An improved caster for the bottom of a stool or other furniture item, the caster comprising a casing containing a compression spring which bears adjustably against a spherical steel ball engaging a floor or supporting surface.
1 Claim, 2 Drawing Figures SPRING LOADED CASTER FOR SHOP TOOLS, BAR STOOLS AND THE LIKE This is a substitute application for my application filed Feb. 25, 1969, Ser. No. 801,982, Group Art Unit 357, now abandoned.
This invention relates generally to furniture casters.
A principal object of the present invention is to provide an improved caster having a rotatable spherical ball for engaging a supporting surface, and wherein the ball is spring loaded for frictional controlling of the rotation thereof.
Another object is to provide an improved caster wherein the spring tension on the ball is manually adjustable for controlling the slidable mobility of the stool across a floor.
Another object is to provide an improved caster wherein the ball is spring loaded in a selected angular direction so to absorb external shock in a specific direction, and which would accordingly be suitable in specific areas subject to the same.
Other objects are to provide a spring loaded caster for stools and the like which is simple in design, inexpensive to manufacture, rugged in construction, easy to use and efficient in operation.
These and other objects will be readily evident upon a study of the following specification and the accompanying drawing wherein:
FIG. 1 is a side cross Sectional view of one form of the present invention, and
FIG. 2 is a similar view of a modified form thereof.
Referring now to the drawing in detail, and more specifically to FIG. 1, the reference numeral represents a spring loaded caster for stools and the like according to the present invention, wherein there is a case 11 having a central chamber 12, the case having a cylindrical side wall 13, top wall 14 and bottom wall 15. The top wall has an opening 16 receiving a shaft 17 secured to a stool leg. A set screw 18 in the side wall secures the leg at a selected elevation. A flat end flange 19 on the shaft bears against one end of a compression coil spring 20, the opposite end of the spring bearing against washer 21 seated on spherical steel ball 22. The ball is rotatable within a seat 23 of the bottom wall the ball extending downward through the wall.
In operative use, tension against the ball is manually adjustable by means of the screw 18, so to control the rollability thereof.
In FIG. 2 a modifiedconstruction 24 includes the above parts, but additionally incorporated the following modification. The set screw 18 extends into a key way 25 of the shaft so to prevent rotation of the caster unit; the screw bearing against the key way bottom wall. Also the lower end of the spring 20 bears against a bearing block 26 fitted over the upper end of the ball; the block being angularly adjustable by a set screw 27 selectively receivable in threaded openings 28 in the case side wall 13; the block 26 having conical side 29 against which the screw 27 bears. Thus an angular direction of force is applied against a floor so to resist horizontal travel in a particular direction, such as when upon inclined floors such as on a ship deck or the like.
The novel features and the operation of this device will be apparent from the foregoing description. While the device has been shown and the structure described in detail, it is obvious that this is not to be considered limited to the exact for m disclosed, and that changes may be made therein within the scope and spirit 0 e invention.
Having thus set forth and disclosed the nature of this invention, what is claimed is: I
1. In a caster for stools and the like, the combination of a case, a rotatable ball supported on a lower end of said case for engaging a supporting floor, means for securement to a lower end of a stool leg, and means for frictional adjustable to control the rollability of said ball on said floor, wherein said securement means to said stool leg comprises a shaft secured to said leg, said shaft extending through an opening in an upper end wall of said case, a compression spring bearing against a bottom face of said shaft and at its opposite end bearing against a block fitted over said ball, and said adjustable means comprising a set screw in said case securable against a side of said shaft, wherein said block has a conical wall, said case has a plurality of radial, threaded openings selectively receiving a screw adjustably engaging said conical wall of said block for providing angular force by said spring against said ball.