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Publication numberUS793612 A
Publication typeGrant
Publication dateJun 27, 1905
Filing dateOct 22, 1903
Priority dateOct 22, 1903
Publication numberUS 793612 A, US 793612A, US-A-793612, US793612 A, US793612A
InventorsJohn W Self
Original AssigneeJohn W Self
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Bal-bearing caster.
US 793612 A
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Description  (OCR text may contain errors)

No. 793,612. PATENTBD JUNE 27, 1905.

' J. W. SELF.



l Fly. 2- f 22 20 2g 21 /]8 NTTED STATES Patented June 27, 1905.

PATENT Crrrcs.


SPECIFICATION forming part of Letters Patent No. 793,612, dated June 27, 1905.

Application filed October 22, 1908. Serial No. 178,098.

To all whom it may concern.-

Be it known that I, J OHN W. SELF, a citizen of the United States, and a resident of Kansas City, in the county of Jackson and State of Missouri, have invented new and useful Improvements in Ball-Bearing Casters, of which the following is a specification.

My invention relates to swivel ball-bearing casters for pianos and other purposes for which casters are used, but mainly for pianos.

My first object in producing such a caster is to provide means by which a heavy piano or other weighty objects carried by the caster may be easily moved or shifted from one place in the house to another.

Another object that I have in view for producing such a caster is that it is susceptible of long durability and not liable to get out of repair.

Referring now to the accompanying drawings, Figure 1 illustrates the end view of a piano with my invention in position in the base thereof. Fig. 2 illustrates an enlarged view of my invention in section in position in the base of the piano, the base portion being also in section with a supporting-yoke and caster-wheel in elevation. Fig. 3 illustrates the casing in elevation that incloses the balls and ball-bearing mechanism, which are shown in section at Fig. 2. Fig. 4 is a screwthreaded stem, the lower end of which is bifurcated or provided with a yoke adapted to straddle the caster-wheel, the screw-threaded end being adapted to hold the casing and its interior parts that carry the balls in position, as seen also at Fig. 2. Fig. 5 is a sectional view of the caster-wheel supported by the yoke portion of Fig. 4, taken on line a a of Fig. 4. Fig. 6 is a plan in elevation of either side of Fig. 4, disclosing the position of the balls when the nuts and convex-faced disk are removed. Fig. 7 is a top plan view of my invention as seen in Fig. 1 when the cap of the encasement and the annular series of small balls, together with the small convex disk and the inverted convex disk,are removed, disclosing the position of the annular series of large balls in position. Fig. 8 discloses a washer and its position on the shaft as seen at Fig. 5, the shaft being in section taken on line 6 b of said figure. Fig. 9 is a top plan view of my invention as seen before it is inserted in the base of a piano, the same as seen in section at Fig. 2.

With the above explanation I will now further proceed to describe my invention by referring to corresponding numerals on the drawings and specification, in which 1 illustrates a piano, and 2 the base of the same with my invention in position in the base portion thereof. The portion that is inserted in the base is inclosed in a circumferential casing 3. Said casing is screwthreaded externally at the top, as indicated. by 4, and is provided with a flange or base 5 at the bottom, as shown. The casing is secured to the piano by means of screws 6, inserted through screw-holes? of said base 5. I have further provided a vertical stem 8 and a castersupporting yoke 9 integral therewith with a caster or roller in position, as shown. Said stem is screw-threaded with a reduced screw-threaded extension 10 at the top. The object of said stem is to extend vertically through the casing 3, and the object of said yoke is to support a caster-wheel, as shown, which will be referred to later on.

At the lower portion of the stem resting on a shoulder 11 is a convex-faced disk or cone 12. Resting over said cone and supported. on the screw-threaded stem is an inverted cup 13. Between the cup 13 and the cone is an annular series of balls 14. Said cup is provided with an annular flange 15, which is adapted to engage a recess 16 in the ease or the casing 3. Said flange so engaging said recess forms a firm support to said cup in maintaining the balls in position against a convex-faced disk 12. A short distance above said inverted cup 13 is another cup 17 of the same dimensions. This cup is also provided with an outward-extending annular flange 18, said flange 18 resting on the top portion of the casing 3. Said cup 17 supports another annular series of balls, as shown. Supported on said screw-threaded stem above said balls is an inverted convex-faced disk 19, said cup 17 and said disk 19 forming a pathway for the second annular series of balls above the first series below, as shown. Mounted on the extended portion of said vertical stem and screwed down theretois a small convex-faced disk 20, and supported on the upper portion of the encasement 3 is an internal-screwthreaded cap 21. Said cap is provided with an upward extension 22, central thereof, of suflicient dimensions to embrace the said disk 20. In the angles of said extension and the convex-faced disk is a third annular series of balls 23, as shown in Fig. 2. I have further provided a pair of outwardly-extending lugs 24, integral with the top of the casing 3. These lugs engage recesses in the outwardly-extending flange of the cup 17. The object of these lugs in engaging the recesses is to prevent the cup from changing its position on the extended screw-threaded stern. I have further provided recesses 26 in the faces of the disks. The object of these recesses is to be engaged with a suitable tool, so that they can be turned either way for insuring proper tension or hearing against the several series of balls. The caster-wheel that engages the floor (seen at Fig. 5) is similarly constructed to the parts inserted in the base of the piano.

27 is a rim or tire. Said rim is engaged and held in position by flanges 28, as shown. The openings through said flanges are screwthreaded and are screwed to a hollow shaft or sleeve 29, and rigidly secured in the bore of said sleeve is a pair of ball-supporting cups 30 and 31, as shown, with their open ends outward toward the open ends of the sleeve. These cups are provided with center openings of a suflicient size to admit a horizontal shaft 31 to loosely pass therethrough. Said shaft is screw threaded right and left, as

at Fig. 2 and Fig. 4:, are provided with openlngs at the lower ends, through which the ends of shaft 31 pass. Said arms when in position loosely impinge the outer faces of disks 32 and are held in position by screwtaps 34 and washers 35 between said taps and the lower ends of arms 9. In order to prevent the washers from turning on said shaft,

I have provided a slot 36 therein and a corresponding lug 37 in the bore of the washer to engage said slot. The outer edges of the flanges 28 are provided with notches or slots 38. The object of these slots is for convenience in tightening the said flanges against the sides of the rim 27.

Having now fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is

In a bali-bearing swivel-caster of the character described, the combination of an annular flanged recessed casing, a detachable recessed cap supported on the casing; a vertical ball-supporting stem central of the casing, a convex-faced disk supported on the lower portion of the stem, an inverted flanged cup supported on said stem inclosing said disk, the flange thereof engaging the recess in the lower end of the casing, an annular series of balls supported by the disk and the inverted cup, a flanged rim-cup 17 supported on the vertical stem above the inverted cup. the flange thereof resting on the upper end of the casing, an inverted disk 19, and said cup 17 supporting a second annular series of balls, a disk mounted on the reduced extended portion of the vertical stem 8, an extended cap adapted to inclose said disk and the reduced portion of the stem and an annular series of balls supported by the angles of the cap and the convex face of the disk, substantially as described.

In testimony whereof I affix my signature in the presence of two witnesses.




Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4316305 *Jun 13, 1980Feb 23, 1982Wil-Mat CorporationSwivel caster assembly
Cooperative ClassificationB60B33/0002