US3059888A

US3059888A - Rotary seat construction having novel bearing means therein

Info

Publication number: US3059888A
Application number: US11292A
Authority: US
Inventors: Lie Finn
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-02-26
Filing date: 1960-02-26
Publication date: 1962-10-23
Anticipated expiration: 1979-10-23

Description

Oct. 23, 1962 F. LIE 3,059,888

ROTARY SEAT CONSTRUCTION HAVING NOVEL BEARING MEANS THEREIN Filed Feb. 26, 1960 INVENTOR.

FINN LIE BY 46 45 v Wmsom, Lewls Mc EAE A TTORN EYS EJ315938 Un1ted States Patent Office 0,. 23,1962

3,059,388 ROTARY SEAT CONSTRUCTIUN HAVING NOVEL BEARHNG MEANS TIEEREHN Finn Lie, Ring tation, near Hamar, Norway Filed Feb. 26, 196i), Ser. No. 11,292 3 Claims. (Cl. 248-161) This invention relates to a seat construction, and particularly to a swivel seat construction and novel bearing mechanism for permitting free rotary movement of the seat and vertical adjustment thereof when desired.

In rotary seat constructions, and particularly in oflice chair seats, it is desirable that the seat be capable of easy swivelling motion without wobble or play such as would make the seat unstable or unsafe for the user. Additionally the seat construction should be capable of ready vertical adjustment in accordance with the particular needs of individual users. The features of non-wobble action, easy rotatability, and ready vertical adjustment should be available in a construction having relatively low cost so as to enable the complete assembly to be supplied competitively with other prior art structures.

With the above points in mind, it is a primary object of the invention to provide a seat structure having improved features of low cost, easy rotatability, and rapid vertical adjustment.

A further object of the invention is to provide a seat construction having a vertical adjustment structure which may be operated by a stenographer or other persons having a minimum knowledge of mechanical structures.

It is an additional object of the invention to provide a rotary seat structure having an improved novel bearing structure of long life and improved anti-wobble construction.

Another objects of the invention is to provide a hearing structure having design features for incorporation of lubricant therein.

A further object of the invention is to provide a bearing structure having a relatively silent operation.

Another object of the invention is to provide a bearing structure adapted to handle radial and end thrust loads in a manner to prevent any wobble of the rotary element.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a vertical sectional view taken through a chair construction incorporating features of the present invention.

FIG. 2 is a sectional view taken on line 22 in FIG. 1.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring to the drawing there is shown a chair construction including a conventional base structure 10, a conventional seat structure 12 having a threaded spindle 14 carried therebeneath, and a novel mechanism 16 for rotatably 'adjustably mounting the seat structure and spindle structure on the base structure 10.

Base structure comprises a generally conventional leg structure 18. Structure 18 carries an upwardly opening steel tube 20 having a lower end 22 and a flaring upper end 24 defining a general conical bearing surface 26. The threaded spindle 14, provided with threads 14a extends into the tube 20 through a frustro-conical bearing element 30 having a relatively large annular end face 32 and a relatively small annular end face 34. The central opening 36 of bearing element 30 clears the threads 14a. Element 3% is preferably formed of nylon or other plastic material having good impact resistance and anti-friction properties.

The bearing element is prevented from having any rotation with respect to spindle 14 by means of a key extending into a groove 4G in the spindle 14.

Seated on the upper face 32 of element 30 is a nut 42 having diametrically opposite grooves '44 formed in its lower face to receive projections 46 formed on hearing element 30. if desired, additional grooves and projections could be provided between members 30' and 42 for ensuring a locking action. The nut 42 is of course threaded on the spindle 14 the arrangement being such that when the occupant is seated on the chair the assembly of elements 14, 3t} and 42 is keyed together; as a result the occupant is enabled to freely rotate the seat structure around the axis of tube 2th. The bearing element 30 takes the end thrust as well as the radial thrust so as to cooperate with tube 20 in preventing any wobble or play of the seat structure. In this manner the seat structure is confined to rotary motion, and the occupant feels a sense of safety and ease which is not present with wobbly chair construction.

Conical surface 5i) of bearing element 30 is preferably provided with a series of annular indentations or grooves 52 which have the effect of preventing squeaking noises such as are sometimes encountered with plastic bearing constructions. Additionally the grooves may receive grease or other lubricant for further enhancing the selflubricating qualities of the plastic bearing element material, the arrangement being such as to provide a noiseless, long-life construction requiring a minimum of maintenance.

The long-life character of the construction is further enhanced by the fact that the bearing element is enclosed on its surfaces by the other components so as to preclude any cold flow of the bearing plastic material during application of heavy loads onto the seat structure. Thus, the upper face 32 of the bearing element 30 is engaged by the lower surface of the nut 42, the concal surface 5%] of the bearing element 30 is completely encompassed by the flaring portion 24 of tube 20, and the annular surface 36 of the bearing element is engaged by the surface of spindle 14. The result is such that abnormal loads do not provide any appreciable deformation or cold flow.

It will be noted from FIG. 2 that the bearing element 30 is provided with a vertical slit 54. The purpose in this slit is to enable the bearing element 30 to change dimension circumferentially under load so as to make intimate bearing engagement with as much of the bearing surface 26 as possible. This compensates for manufacturing inaccuracies in forming the flare 24. The action is such as to provide an automatic centering of the spindle relative to the axis of the tube 20 so as to cooperate with the tube in providing a smooth anti-friction, antiwobble arrangement. In this connection it will be noted that the spindle is accurately guided at two widely spaced points, i.e., by element 30 and at the lower end portion of sleeve 20. The threads 14a are of slightly less major diameter than the internal diameter of tube 2% in order to prevent wear.

It has been previously pointed out that seat structure 12 is preferably mounted for vertical adjustment relative to base structure 10. In performing the vertical adjust ment operation, seat structure 12 is lifted so as to lift spindle 14 relative to the tube 20. The nut 42 is meshed with the spindle threads 14a and it will accordingly be lifted with the spindle 14. However, bearing element is somewhat loosely received on the spindle and the bearing element 30 may not lift with the spindle 14 from the tube 20, i.e., there may be a lowering of the bearing element 30 on the spindle 14 when the seat structure is lifted. When the spindle 14 is lifted nut 42 may be rotated on the spindle 14 to a new position of adjustment, either upwardly or downwardly from its illustrated position. The seat structure can then be lowered, with the bearing element 30 seating on the conical bearing surface 26. If the projections 46 do not register with recesses 44 the seat structure and spindle assembly can be rotated until the recesses drop down onto the projections. Thereafter the projections serve to automatically lock the nut onto the bearing element 30. Since as previously noted, the bearing element 30 is locked onto the spindle 14 by the lug-groove means 38, 40, the entire assembly of

elements

12, 14, 30 and 42 is adapted for rotation relative to the base structure 10.

It is an object of the present invention to provide a rotary seat-support arrangement having improved anti- Wobble action over a relatively long service life, and accordingly it is preferred to eliminate any steel-to-steel engagement of movable parts such as would cause ex cessive wear or noise. To eliminate such wear, particularly at the lower end of the spindle, there may be provided one or more nylon or other plastic collars 39, each preferably having bevelled faces as at 41 for defining grooves 43 to accommodate grease or other lubricant if desired.

The collars 39 may be provided with a lug (not shown) similar to previously discussed lug 38, and the collars are secured against axial displacement along the spindle by any suitable means, as for example press fit, set screw means, or flanging of the spindle.

It vw'll be understood that use of collars 39 in combination with bearing 30 provides two spaced supports for the spindle. By this arrangement there is a minimum tendency of the chair to wobble in service. The pre ferred use of nylon or other plastic material for hearing 30 and collars 39 results in minimum Wear, long service life, and minimum noise. In some instances the plastic may give a slight squeaking noise, and in order to counteract such noise the tube 20 may be filled with grease, oil or other lubricant. A suitable closure 45 may be provided on the lower end of tube 20 to retain the lubricant within the tube.

It will be seen that the illustrated construction is susceptible to very low cost manufacture since a minimum number of component parts are required. In operation the elements have a smooth, trouble free movement which contributes materially to prolonged service life. It will \be understood that various modifications may be resorted to without departing from the spirit of the invention as defined in the appended claims.

I claim:

1. In a chair construction the combination comprising a base structure defined by a vertical tube having a flaring upper end portion forming a conical bearing surface; an annular deformable bearing element having a conical face, said face being seated substantially entirely within said bearing surface; a nut removably carried on said bearing element; means between said bearing element and nut for preventing relative rotary movement therebetween when the nut and bearing element are engaged with one another; a seat structure having spindle threaded into the nut and extending through the bearing element into the vertical tube; means between the bearing element and spindle for preventing relative rotary movement between the spindle and bearing element while permitting axial movement of the spindle relative to the bearing element; the arrangement between the bearing element, nut and spindle being such that when the bearing element is pressed against the conical bearing surface the bearing element-nut-spindle assembly can be rotated as a unit relative to the tube, but when the spindle is lifted relative to the tube the nut can be disengaged from the bearing element and threaded along the spindle to a new position for establishing a vertical adjustment of the spindle and seat structure relative to the base structure.

2. In a chair construction the combination comprising a base structure defining an annular upwardly flaring bearing surface; an annular plastic bearing element having an annular upwardly flaring face rotatably seated on said bearing surface; a nut removably carried on said bearing element; the spacing between the nut and the outermost portion of the bearing surface being such that the bearing element is substantially completely enclosed by the nut and bearing surface to prevent cold flow of the plastic bearing element material; means between said bearing element and nut for preventing relative rotary movement therebetween when the nut and bearing element are engaged with one another; a seat structure having a threaded spindle meshingly engaged with the nut threads and extending through the bearing element; and means between the bearing element and spindle for restricting the spindle to axial movement relative to the bearing element; the arrangement between the bearing element, nut and spindle being such that when the bearing element is pressed against the bearing surface the bearing element-nut-spindle assembly can be rotated as a unit relative to the base structure, but when the spindle is lifted relative to the base structure the nut can be disengaged from the bearing element and threaded along the spindle to a new position for establishing a vertical adjustment of the spindle and seat structure relative to the base structure.

3. An axially adjustable rotatable connection compris ing means forming an annular dish-shaped bearing surface; an annular bearing element rotatably engaging said bearing surface; a nut removably engaged with said bearing element; means between said bearing element and nut for preventing relative movement therebetween when the bearing element and nut are engaged with one another; a spindle threaded into the nut and extending through the bearing element; and means between said bearing element and spindle for restricting said spindle to axial movement relative to the bearing element; said bearing element having an axial slit therethrough to permit circumferential change of dimension of the bear ing element under change of axial load.

References Cited in the file of this patent UNITED STATES PATENTS 504,460 Snider Sept. 5, 1893 682,844 Ellenbecker Sept. 17, 1901 1,332,200 Borgarello Mar. 2, 1920 1,937,892 Huntley Dec. 5, 1933 2,542,469 Bolens Feb. 20, 1951 2,561,102 Elleman July 17, 1951 2,742,082 Lief Apr. 17, 1956 2,859,799 Moore Nov. 11, 1958 2,936,166 Wise May 10, 1960 2,939,517 Saarinen June 7, 1960 FOREIGN PATENTS 800,885 Germany July 8, 1949