US1428899A - Caster - Google Patents

Description

A. K. NIXON.

EASTER- APPLICATION FILED JULY 27.1921.

PatentedSept. 12, 19220 I 121M822 tor A ll) ion KNizon fliiorn egr Patented Sept. 12, 1922.

- UNITED STATES 1,428,899 PATENT orrlcs.

ALBION K. NIXON, OF SAN FRANCISCO, CAL]:IEQIRNJLL, ASSIGNOR O'F ONEFH'IALF TO ALBERT GASFER, 0F VALLEJO, CALIFORNIA.

(FASTER Application filed July 27, 1921. Serial No. 487,935.

To all whom it may concern:

Be it known. that I, A BI K. NIXQN, a citizen of the United States, residing in the city and county of San Francisco and State of California, have invented new and useful Improvements in Casters, of which the following is a specification 'This invention relates to a caster, and especially to a caster of the compound roller type.

One of the objects of the present invention is to generally improve and simplify casters such as are used in conjunction with heavy furniture, pianos or the like, and especially to. provide a caster in which rolling friction is greatly reduced, 1narring of the floor surface, etc}, prevented, and in which jarring of the article supported and resistance to override an obstruction when encountered is reduced to a minimum.

Further objects will hereinafter appear. The invention consists of the, parts and the construction, combination and arrangement of parts as hereinafter more fully de scribed and claimed, having reference to the accompanying drawings, in which Fig.1 is. a side elevation of one form of the caster,

Fig. 2 is a cross section of the same. Fig. 3 is a perspective view of the roller guard.

Fig. 4 is. a side elevation of another form of thecaster.

I Fig. 5 is a cross section of the same.

i Referrin to the drawings in detail, and particularly to Fig. l, A indicates the shank of a caster, 2 the upper head, 3 the lower head, and 4 the bearing arms of the caster. The heads 2 and 3 are secured with relation to each other in the usual manner as indicated at 5, and a ball bearing race 6 is interposed between the head members to permit a free swivel action between the same. The arms 4: of the caster are interposed as shown in Fig. 2, and connecting the lower ends of the arms is a bearing pin 7, upon which is journaled a roller 8. This roller is disposed within a second roller generally indicated at 9 which will hereinafter be termed the track rmg. This ring is formed of shee me or any suitable material, and is considerably largerin diameter than the roller 8. Formed. on the inner side of the ring is an annular rib or ridge l0, and formed in the center p on f the roller 81s a gr v ll, which permits the roller 8 to straddle the rib 10,

thus permitting the rib to form a track for the'roller 8, which secures said roller against lateral movement with relation to the track member.

By referring to Figs. 1 and 2, it will be seen that the diameter of the roller 8 is so small when comparison is made with the interior diameter of the track member 9, that unless means were provided for main-. taining the roller 8 in constant engagement with the inner side of the track member. displacement of the ring or roller 8 might take place. To avoid such displacement, a guard generally indicated at 12, has been provided. This guard consists of a pair of arms 14:, the lower ends of which are per.- forated as at 15 to permit the pin 7 to pass therethrough. The upper ends of the arms 14 are connected by a cross-piece 16, and this piece is bent or grooved as at 17 to straddie the rib or track 10. The guardthus formed maintains the roller in constant engagement with the inner surface of the track member and the rib 10, and thus prevents displacement of the roller with relation to the track member or vice versa.

In the other form of the invention illustrated in Figs. 4 and 5, a track ring 18 is employed. The inner surface of the 'ring is concaved as at .19 to form a track for aroller 20. The exterior surface. of this roller is convex to conform with the inner formation of the track ring. The caster in general, illustrated in Figs. 4 and 5, is also provided with a pair of connected swivel heads 21 and 22 and the bearing lugs shown at 23 support the bearing pin 24:, upon which the roller 20 is journaled.

For the purpose of securing the roller against lateral movement, and also for the purpose of maintaining it in engagement with the inner track surface 19, a pair of side plates 25 and 26 have been provided. These side plates enter annular recesses 27 and 28 formed in the respective sides of the track ring, and they. are freely turnable in these recessesandi they are also freely turnable upon the pin 24. i

To prevent unnecessary friction between the track ring and the side plates 25 and 26, and between theend surfaces of the roller 20, the pin 24: is shouldered as at 30. This shouldering of the pin maintains a predetermined spacing between the roller 20 and the the same function as the guard 12 and the annular rib or track member 10. 7

There are three main objects sought in the present invention: First, to minimize rolling friction; second, to prevent marrin of I surfaces rolled over or upon, and thir to I 65 iat41, the track ring remains stationary and prevent jarring of the article supported and resistance to override an obstruction when encountered.

The first object is obtained by-providing the compound rollers indicated at 8 and 9. The rolling friction takes place between the I outer surface of the smallroller and the in ner surface of the trackring. The inner surface of said track ring, where depressions would have a tendencyto exist, is composed of material of a harder substance than the planes which sustain the outer'ring when in motion. The depressions which would be caused on the'surface of the material: rolled upon, when a load is applied to the roller, will be minimized. The inner surface of the track ring being curved gives more of a bearing surface to the small roller than would be given if the roller came in direct contact with a plane surface, such as a'wooden floor, thereby decreasing depression and minimizing friction.

The second object is obtained by applying soft rubber, or other suitable material, to the outer portion of the track ring as indicated at 40. This surface comes in contact with the hard wood floor when in motion; the rubber forming a' cushion between the roller, the track ring and the floor. Actual rolling wear and tear take place on the insidesurface of the track ring, that is the ring acts as a track only when the roller is in motion.- The soft rubber on the outer surface of the track ring gives a large bearing support when a load isvapplied, and it does not hinder the rolling effect of the track ring.

T e third object is obtained by employing the track ring. When it approaches: an obstruction, for instance, such as indicated forms an inclined track for the roller 8 between thepoints indicated at 42 and 43. The roller 8 rolls within the track ring while this remains stationary, that'is the roller 8 moves from the point 43 to the point 42 and when it passes the high pointof the obstruction, which is indicated at 42, it is obvious that the :track'ring will'follow and that the track ring'and the roller will become centered with relation to each ether when a plane} or even surface" is again reached. I i a This action of the two rollers one with relation to the other is important as it not only lessens the jar to the article supported, but it materially reduces the amount of power or force required to override an obstruction.

While certain features of the present invention are more or less specifically illustrated, I wish it' understood that various changes in form and proportion may be resorted to within the scope of the appended claims, similarly that the materials and finish of the several parts employed may be, such as the experience and judgment .of the manufacturer may dictate or varying. uses yd ma d- Having thus described my invention, what I claim and desire to secure by Letters Pat ent is g '1. In a device of the character described, a compound roller support comprising a circulartrack member, and a roller adapted to travel on the inner surface of the tr'ack mem-. ber'gone'of said members having a groove therein and the other of said'me'mbers being formed to operate in said groove. 7

2. In a device of the character described, a compound roller support comprising a circular track member, and a roller adapted to travel on the inner surface of the track member, one of said members having'a groove therein and the other of -said meme bers being formed 'to operate in said groove, and a guard device arranged between. the track member and the roller members to maintain said members in cooperative relation.

3. A device of the character described comprisin a swivel head, a pair of bearing arms carried by the head, a bearingpin disposed between the arms, a roller journaled thereon, a track ring exterior of theiroller thereon, a track ring exterior of the roller having an inner track surface for the reception of the roller and an exterior-track surface for engagement with the surface rolled upon, and a guard member pivotally supported by the bearing pinand engage able with the track ring to maintain" the roller in constant engagement therewith.

5. A device of the character described comprising a swivelhead,"a pair of bearing arms carried by the head, a bearing pin disposed betWeen the arms, a roller Journaled thereon, a track ring exterior of the roller having an inner track surface for the reception of the roller and an exterior track surface for engagement With the surface rolled upon, an annular rib formed on the inner track surface and centrally thereof, an annular central groove in the roller permitting the roller to straddle the rib, and a bailshaped guard pivotally mounted on the bearing pin, the upper end of said guard being recessed to straddle the annular track rib.

6. In a device of the character described a swivel head, a pair of bearing arms carried thereby, abearing pin supported by the arms, a roller journaled thereon, a track ring surrounding the roller and having a track surface on its inner side for the reception of the roller, and an exterior track surface for engagement with a surface to be rolled upon, an annular recess formed in each side of the track ring, and a circular plate forming a closure for each side of the track ring, and adapted to be received by said recesses, said plates being eccentrically journaled upon the bearing pin.

7. In a device of the character described a swivel head, a pair of bearing arms carried thereby, a bearing pin supported by the arms, a roller journaled thereon, a track ring surrounding the roller and having a track surface on its inner side for the reception of the roller, and an exterior track sur face for engagement with a surface to be rolled upon, an annular recess formed in each side of the track ring, a circular plate forming a closure for each side of the track ring and adapted to be received by said recesses, said plates being eccentrically journaled upon the bearing pin, and means for maintaining said-plates out of frictional engagement With the roller and the track ring.

ALBION K. NIXON.

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