US 2905229 A
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Description (OCR text may contain errors)
Sept. 22, 1959 R. N. ADAMS 2,905,229
ROTARY STOOL Filed NOV. 8, 1955 r-ni? 76 I INVEN TOR. RAYMOND N. ADAMS ATTORN I- a ROTARY STOOL Raymond N. Adams, Cincinnati, Ohio Application November 8, 1955, Serial No. 545,736 3 Claims. ((31. 155-95) The present invention relates to a rotary stool, that is, a stool in which the seat element may rotate on a vertical axis relative to the base of the stool.
An object of the invention is to provide a rotary stool comprising duplicate seat and base elements which are made identical and interchangeable, so that manufacture and assembly costs are reduced to an absolute minimum.
Another object is to provide a rotary stool of the character stated, Whichis so constructed as to sustain extraordinary weight without danger of collapse or injury to the stool or its user.
A further object of the invention is to provide a stool having the advantages above stated, which may be fabricated almost wholly of a light-weight durable plastic material which requires no finishing or decorating other than that which is inherent in the material itself, with the result that great savings in time and labor costs are achieved.
Another object is to provide a stool of the type above described, which is easily shipped, moved, and stored due to its light weight characteristic, and which may be used without danger of tilting or collapsing even when subjected to extraordinary abuse.
Another object is to provide a stool having the characteristics above mentioned, whose duplicate base and seat elements are inexpensively mounted on unique roller bearings, the bearing being Wholly non-metallic and requiring no lubrication or other servicing.
The foregoing and other objects are attained by the means described herein and as illustrated upon the accompanying drawing, in which:
Fig. 1 is a perspective view of the rotary stool embodying the invention.
Fig. 2 is a cross-sectional view of the same, taken on line 2-2 of Fig. 1.
Fig. 3 is an enlarged cross-sectional view taken on line 3-3 of Fig. 2.
Fig. 4 is a fragmentary cross-sectional view of a bearing retainer forming a detail of the invention.
With reference to the drawing, Fig. 1 shows the stool of the invention to comprise a pair of generally frustoconical body elements A and B each having a constricted inner end 10, 12, and an outer enlarged end 14, 16, the latter being permanently closed by means of upper and lower end members or heads 18 and 20. For simplicity and ease of manufacture, the body elements may be made identical in form and size; however, if for any reason it should be considered desirable to construct the stool with one body element larger than the other, or of a different form or shape, that may be done without departing from the scope and purpose of the invention. It will be obvious, however, that the use of the same dies or forming equipment in fabricating the upper and lower body elements, will necessarily result in economies in manufacture and assembly.
As best illustrated in Fig. 2, the body elements A and B are rotatably interconnected by means of a central 2,905,229 Patented Sept. 22, 1959 shaft or stud 30 and an anti-friction bearing denoted generally by the numeral 32.
The following description of the body element A will sufiice also for the body element B, as the parts are preferably identical. The constricted inner end portion .10 of the body element is spanned by a transverse end wall 22 which preferably is formed integrally with the body element. The wall 22 may be substantially planar in form, with its plane normal to the axis of rotation of the body element. Centrally of the Wall 22 is formed a hub 24 which extends inwardly toward the head 18, and this hub also is formed integrally with the body element and with the transverse wall 22. The hub is cylindrical and has a central bore or bearing 26 to accommodate the stud 30 which may rotate therein.
Along the outer periphery of the transverse wall 22 there is formed an annular channel 34 providing a race for the rollers 36 of the bearing 32. The depth of the channel forming the race is slightly less than half the diameter of the rollers, and an annular lip 38' formed on the frusto-conical wall of the body element may serve as a cover for the bearing. A similar lip on the secondbody element coincides with the lip 38, and forms therewith a very constricted annular slit 40 sufficiently limited in width to preclude entry of the fingers of the hand, into the bearing area.
For imparting rigidity to the bearing race and the hub 24, a series of radial reinforcing ribs 42 is integrally formed with the wall 22 and the adjacent conical wall of the body element. The reinforcing ribs are integral also with the hub 24, and they extend inwardly of the body element toward the head 18, concealed within the structure. The outer ends of the reinforcing ribs may be en-I larged and extended along the inner face of the body element Wall, as indicated at 44, to further reinforce the junction between the body element wall and the transverse end wall 22.
The roller bearing structure includes the series of cylindrical rollers 36, which rollers are maintained individually spaced by means of the retainer illustrated by Fig. 4. The retainer may consist of a plastic ring having inner and outer concentric upright Walls 52 and 54 spaced apart a distance slightly greater than the length of a roller 36. At intervals, the walls 52 and 54 are spanned and connected by horizontal webs 56 which are confined between two radially extending upright abutments, indicated at 58 and 69, leaving an open space 62 into which a roller 36 may be loosely fitted for rotation. The rings 52, 54, and the abutments 58, 60, form cages for the rollers as the rollers travel in the raceways provided by the transverse wall structures of the upper and lower body elements A and B.
As will be understood, the height of the ring portions 52 and 54 of the retainer is slightly less than the diameter.
of a roller, so that the rollers are free to travel in the races without interference from the retainer other than the roller spacing effect thereof. By referring to Fig. 2, it will be noted that the retainer as well as the rollers, rides Within the confines of the raceways. The retainer is a floating structure, that is, it has no attachment to any part of the raceway or the wall 22, and may therefore shift rotationally within the bearing raceway as the body ele ments A and B are rotated relatively.
In the preferred form of the invention, the rollers 36 of the bearing are made of nylon or other appropriate plastic material which is highly resistant to wear, noiseless in operation,and requires no lubrication. Rollers of this type are light in weight, and possess the further advantage that they do not cut or wear the plastic raceways of the body elements. 'In the environment shown, assembly of the bearing is a simple and rapid procedure involving only the placement of the retainer within the raceway, of one body element such as B, then dropping the rollers into the 7 spaces 62. Thereafter, the other body element A may be placed atop the body element B, as shown in Fig. 2, with both raceways embracing the bearing, whereupon the stud 30 may be passed'through the hubs 24 and secured against displacement to join the body elements for rotational movement. The assembly procedure just described is performed prior to application of the heads 18 and 20, as will be understood.
One satisfactory form of means to secure the stud 30 in position is exemplified by Fig. 2, and may involve the use of a stud having annular grooves 70-70 formed near its opposite ends, to receive the resilient split rings 72 72 which clamp onto the studs. Washers 7 4-74' may be interposed between the split rings and the adjacent ends of the hubs, to take up any end play and preclude scoring of the hubs by the split rings. The Washers, the stud, and the split rings may be of metal by preference, and may constitute the only metal parts in the entire stool structure.
Like the body elements A and B, the end members or heads 18 and 20 are formed of comparatively flexible molded plastic, and are preferably identical to one another. Each head is made in the form of a concave disc, bounded at its periphery by a reinforcing rim 76 grooved on the underside as at 78 to receive the annular enlarged end 14 of the conical body element. The joint formed at groove 78 may be cemented, fused, or otherwise made secure, as the final step in the assemblby of the stool.
By preforming the concavity in each head as shown, maximum structural strength of the structure is assured without any tendency of head distortion to break the joint at 78 when Weight is applied to the head. Moreover, the concavity overcomes any possibility of head distortion to bulge the head outwardly and thereby render the stool unstable while standing upright, as in Fig. 2. Tests for structural strength of the construction above described have proven highly satisfactory from the standpoints of safety and insurance against collapse due to structural weakness even when greatly abnormal weight and stress are applied to the concave heads. Tipping of the stool is virtually impossible, due to the flare of the body elements and the extensive diameter of the roller bearing between said elements. In this connection it may be noted that the diameter of the roller bearing approximates the height of a body element, to achieve the assurance against initial tipping.
As previously mentioned herein, manufacturing and assembly costs may be greatly reduced by use of the same dies, jigs, and forming equipment in fabricating the identical parts of the stool structure. With the possible exception of the center stud 30, the washers 74, and the split rings 72, the entire structure may be formed from molded plastic material which is light in weight and requires no decorating or surface finishing. The parts may be colored or otherwise decorated incidental to the molding process if desired, and as previously suggested herein the flared body elements may be frusto-conical as shown,
or made generally in that shape with the use of polygonal dies if desired. These and various other modifications and changes in structural details may be resorted to, within the scope of the appended claims, without departing from the spirit of the invention.
What is claimed is:
1. A rotary stool comprising in combination, a pair of identical closed drums each of generally frusto-conical form and each including a head providing identical seats for alternative use, a solid continuous side wall, and a centrally apertured circular end wall in spaced substantial parallelism with a head, said end walls of the drums being equal in diameter, substantially flat, and
' each having an outer margin in close coincidence with the outer margin of the end wall of the other drum, identical annular bearing channels formed in the circular end walls in close proximity to the outer margins thereof and in remote relationship to the central aperture thereof, rolling bearing elements within the bearing channels of both drum end walls adjacent to the outer margins, and a pivot member Within the central apertures of said end walls to rotationally mount the drums one upon the other in axial alignment with the outer margins of the end walls in close parallelism to one another, said pivot member including means concealed inside the closed drums to preclude lateral separation of the drum end walls one from the other, thereby to retain the rolling bearing elements within the bearing channels.
2. The rotary stool as set forth in claim 1, and wherein the diameter of the bearing channel of each drum approximates the height of each drum.
3. The rotary stool as set forth in claim 1, including in combination with the annular bearing channels in the end wall of each drum a molded plastic retainer consisting of a pair of spaced concentric rings connected at intervals by a series of spaced webs molded integrally with the rings and wherein the adjacent edges. of adjoining Webs define spaces for the reception of cylindrical roller bearings.
References Cited in the file of this patent UNITED STATES PATENTS D. 118,295 Tropauer Dec. 26, 1939 899,563 Riebe Sept. 29, 1908 2,641,310 Simjian June 9, 1 953 2,726,907 Krauss Dec. 13, 1955 FOREIGN PATENTS 695,195 Great Britain Aug. 5, 1953 730,426 Great Britain May 25, 1955 OTHER REFERENCES Popular Mechanics Shopnotes, pg. 70, 1936. Popular Mechanics, pg. 199, Nov. 1939.
Product Engineering, pp. 102-107, July 1950. Automotive Industries, pp. 107-108, Sept. 1, 1954.