US3250509A - Chair structure - Google Patents

Description

y 1966 R. P. MOLLOY 3,250,509

CHAIR STRUCTURE Filed July 20, 1954 50 INVENTOR. RICHARD P. MOLLOY BY A! W 464mm! (dings.

United States Patent 3,250,509 CHAIR STRUCTURE Richard P. Molloy, Kalamazoo, Mich, assignor to Bruns- Wick Corporation, a corporation of Delaware Filed July 20, 1964, Ser. No. 383,606 Claims. (Cl. 248-417) This invention relates to a chair structure or the like, and more particularly to a structure including a tubular upright support containing mounting means for adapting the tube to carry a swivel seat or the like.

It is a general object of this invention to provide a new and improved seat assembly.

It is another object to provide a new and improved swivel chair constructed in part from commencially available tubing of any desirable cross-sectional shape.

Another object is to provide a new and improved swivel chair having an upright tubular support which carries a tube adapter fixably secured in its upper end for rotatably supporting a seat mounted thereon.

Further objects are to provide a chair having a mounting adapter for enabling an upright tubular support on the chair to receive a swivel seat, the adapter including means for aligning the adapter inside said tubular support and also having means for locking the adapter to the support; and to provide the mounting adapter with locking means in the form of a horizontally expandable element which may be expanded into engagement with the chair with the seat portion removed and partly in section along the line 22 of FIG. 1 to show the structure used to pi-vota-lly mount the seat;

FIG. 3 is an enlarged axial section view of the assembly mounting device prior to locking it to the seat assembly; and

FIG. 4 is a plan view of an expandable element used to lock the mounting device to an upright tubular support.

While a preferred illustrative embodiment of the invention is shown in the drawings and will be described in detail herein, the invention is susceptible of embodiment in many different forms, and it should be understood that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodimentillustrated herein. The scope of the invention will be pointed out in the appended claims.

Referring now to the drawings in more detail, a chair assembly shown generally at 10 consists of a floor-engaging support or structure 12 supporting an upright tubular member or support 14 having an outer wall or surface 14a, and an inner wall or surface 141) to which is afiixed at its upper end a mounting device or adapter 16 for enabling the tubular support 14 to rotatably carry a forwardly biased swivel seat assembly 18.

The structure 12, as shown, consists of five vertical legs 20 connected together at their top ends as by circular foot rest 22, each leg having a horizontal spoke 24 directed inwardly from its midportions and connected to the lower end of the support 14. Tubular support 14 consists of an elongate tube of generally circular cross-section having its upper portions extending vertically above pedestal L2. The lowermost end 30 of the tube is open to permit entry therein by a socket wrench, to be described more fully "ice later. It will be understood that the specific shape of tube 14 and the manner in which it is supported at its lower portionsmay be varied considerably.

Upper edge 3-2 of the support 14 lies in a horizontal plane, and the upper inner edge of inner wall 14b is beveled as at 34 to facilitate the mounting of adapter 16, as will be described hereinafter.

Adapter or mounting means 16 consists of a main hollow member 36, preferably made of die cast aluminum, having an upper horizontal annular flange 38 forming a downwardly facing horizontal shoulder 40 which rests on the upwardly facing horizontal edge 32 of tubular support 14. Immediately below flange 38 of member 36 is a relatively short taper 42 having an average diameter slightly in excess of the average diameter of bevel 34 on support 14 so as to cause an interference fit therebetween when shoulder 40 is moved down into contact with edge 32. Central portions of member 36 form a sleeve that tapers downwardly to a horizontal shoulder 44 which faces downwardly towards a reduced diameter portion 46, also on member 36, which is threaded to the lower end 50 toreceive a nut 48. Mounted above nut 48, and also on the threads 46, is a vertically movable washer 52. Above washer 52, and similarly mounted for vertical movement over threads 46 is an expandable locking or gripping element 54 having a generally three bladed propeller-like shape in plan view, as can be seen in FIG. 4. Element .54 is formed of metal and has a hole 56- .therethrough for mounting over the threaded portion 46 of the adapter body 36. Element 54 also includes a plurality of outwardly extending and angularly spaced projections 58 having outer edges 60 adapted to engage and grip the inner wall 14b of upright support 14. Projections 58 are tilted downwardly at an acute angle with the horizontal as shown at 62 providing element 54 with an outer diameter sufficiently small to allow its insertion into the tube 14. As will be described in great detail later, nut 48 may be screwed upwardly after insertion of the adapter 16 into the upper portion of the tube 14 to urge washer 52 upwardly into engagement with projections 58 thereby driving them upwardly and into engagement with the inner surface 14b of the tubular support 14. It will be understood that element 54 is compressed vertically and expanded horizontally to lock it incompression to the support 14.

The member 3-6 of mounting adapter 16 includes an integrally cast socket 64 defining a bore 66 of circular cross section therein opening upwardly as at 68, best seen in FIG. 3. Disposed within bore 66 is a piston assembly 7 0 including a spring 72, a follower or piston 74 above the spring and biased upwardly thereby, and a spherical ball 76 supported by and above piston 74.

Member 36 also has a centrally located bore 80 of circular cross section extending vertically therethrough and aligned with tube 14, bore 80 being adapted to receive and support a portion of the seat assembly 18. A circula-r recess 82 of greater diameter than bore 80 is provided in the upper surface of member 36 to form a seat for a plurality of freely rotatable washers 84 (FIG. 2) which act as thrust hearings in rotatably supporting the seat assembly and loads placed thereon.

Seat assembly 18 consists generally of a lower seat supporting casting 86, a seat 88 mounted on casting 86 by suitable fasteners (not shown) which extend through casting 86 as at 90, said seat having an integral bottom portion 92 and backrest portion 94 (preferablyrnolded of plastic), and, if .desired, a cushion resting on or affixed to the upper surface of bottom portion 92 as at 96.

Casting 86 carries a shaft 98 having an upper portion 100 rigidly embedded in casting 86, as by casting it therein, and a lower portion 104 extending through the bore 80 of adapter 16, said bottom portion 104 having threads 106 at its lower extremity extending below shoulder 50 of adapter 16. A plurality of washers 168 are impaled by threaded portion 166 of shaft 98, each having a. central hole 'of a diameter sufficiently large to slide over threads 106 but not sufiiciently large to slide over threads 46 of adapter 16. Washers 108 are held in place by acorn nut v110 which is screwed up on threaded portion .106 of shaft 98 sufficiently to take up any vertical play of shaft 98 without putting it in compression. This mounting prevents seat assembly :18 from being lifted vertically off the support 14 but allows f-ree rotation relative thereto about its vertical axis.

Seat casting 86 also has a cam surface 112 cast into its lower surface, having a circular configuration when viewed from the bottom, and being inclined at an acute angle from the horizontal. C am surface 112 is engaged by ball 76 of piston assembly 70 under the upward bias of spring 72 which tends to rotate the sea-t toward a predetermined forwardly facing position, such as vfacing a table or a bar. 4

In assembling the seat structure, washers 84 are well lubricated and placed over shaft 98 which is then also lubricated and inserted through hole 80 of the adapter assembly 16 so as to have its threaded end portions 106 exposed below the shoulder 50 of the adapter member 36. Washers 108 are then well lubricated, placed over threaded portions 106 of shaft 98, and secured in place by acorn nut 110 which is drawn up to permit relative rotation between shaft 98 and adapter 16 but prevent relative translation therebetween along their common axes. The adapter 16 of the adapter and seat assembly combination is then inserted into the upper open end of the tubular support 14 and pushed downwardly therein to cause taper 42 on the adapter body to mate with bevel 34 on the upper end of the tubular support 14, this taper and bevel forming upper centering means for centering the upper end of adapter body 36 in the tube.

-An extension socket wrench is then inserted through the lower hole 30 of the tube 14 so as to engage nut 48, acorn nut 100 being of somewhat smaller diameter than the nut 48 so that the socket wrench may he slipped over acorn nut 110 so as to turn nut 48 without turning acorn nut 102. Friction between bevel 34 and taper 42 prevents turning of the adapter body 36 relative to tube 14 as nut 48 is rotated. Nut 48 is then drawn up against washer 52 which bears against projections 58 so as to bend them upwardly and outwardly forcing edges 56 into locking engagement with the inner surface 14b of the tubular support 14. Equal spreading of extensions 58 outwardly centers the lower portions of adapter body 36, :which, together with the upper centering means, properly aligns bore 80 with the axis of support 14.

Further tightening of nut 48 creates a downward force on member 36 of the adapter so as to draw shoulder 40 down into abutting engagement with upper edge 32 of the support thereby creating an interference fit be tween taper 42 and bevel 34. It will be understood that the adapter assembly -16 is now fixedly secured to the support 14, and seat assembly 18 is free to rotate but cannot be lifted up and away from the support 14. When provided with the swivel return mechanism, seat assembly 18 may be rotated about a vertical axis and will always return to its forward position when released.

Although the invention is shown including a bar stool mounted on a tube of circular cross section, it will be appreciated that the principles disclosed herein may be incorporated into swivel seats having supports of various configurations and cross-sectional shapes as well as with other types of seats.

I claim:

-1. A swivel seat capable of returning itself to a forwardly facing position, comprising: a floor-engaging support including a hollow tube at the upper end thereof, a swivel seat mounting member carried by said tube in its upper end having an upper flange in part resting on and in .part fitted within the upper end of said tube, a sleeve portion below said flange extending downwardly within the tube and having an externally threaded reduced portion at its lower end, said member having a bore extending vertically therethrough, and a substantially vertical hole offset from said .bore and opening upwardly through the flange; an expandable gripping element mounted over said threaded portion and against a shoulder thereabove and having a plurality of radially extending projections tilted slightly downwardly from the horizontal and engaging the inner wall of the tube; a washer carried by said threaded portion below said element and in contact with said projections; and a nut on said threaded portion below said washer to hold said projections in their extended positions in locked engagement with the tube, thereby securing said member to the tube; a seat assembly having bearing means rotatably carried on said mounting member flange and having a depending shaft extending through said bore, said shaft having a lower threaded portion extending below said member, a nut on the lower threaded portions of said shaft for preventing removal of said seat assembly from said mounting member; said seat assembly also having a generally downwardly facing and arcuately curved cam surface inclined in a plane making an acute angle with the horizontal; and a compression spring carried in said hole with a generally vertically biased follower member thereabove for exerting a force against said cam surface and biasing said seat assembly toward its forwardly facing position.

2. A swivel seat capable of returning itself to a forwardly facing position, comprising: a floor-engaging support including a hollow tube at the upper end thereof,

a swivel seat mounting member carried by said tube in its upper end having an upper flange in part resting on and in part fitted within the upper end of said tube, a sleeve portion below said flange extending downwardly within the tube and having a threaded portion at its lower end, said member having a bore extending vertically therethrough, and a substantially vertical hole offset from said bore and opening upwardly through the flange; an expandable gripping element mounted on said lower end and having a plurality of radially extending projections tilted slightly downwardly from the horizontal and engaging the inner wall of the tube; and a threaded fastener in mating engagement with said threaded portion and exerting a force against said elebore; means for preventing removal of the seat assembly from the mounting member; said seat assembly also having a generally downwardly facing and arcuately curved cam surface inclined in a plane making an acute angle with the horizontal; and a compression spring carried in said hole with a generally vertically biased follower member thereabove for exerting force against said cam surface and biasing said seat assembly toward its forwardly facing position.

3. A swivel seat comprising: a fioor-engaging support including a hollow tube at the upper end thereof, a swivel seat mounting member carried by said tube in its upper end having an upper flange in part resting on and in part fitted within the upper end. of said tube and a sleeve portion below said flange extending downwardly within the tube and having an externally threaded reduced portion at its lower end, said member having a bore extending vertically therethrough; an expandable gripping element mounted over said threaded portion and against a shoulder thereabove and having a plurality of radially extending projections tilted slightly downwardly from the horizontal and engaging the inner wall of the tube;

a washer carried by said threaded portion below said element and in contact with said projections; and a nut on said threaded portion below said washer to hold said projections in their extended positions in locked engage ment with the tube, thereby securing said member to the tube; and a seat assembly having bearing means rotatably carried on said mounting-member flange and having a depending shaft extending through said bore, said shaft having a lower threaded portion extending below said member and a nut on said lower threaded portions for preventing removal of said seat assembly from said mounting member.

4. A swivel seat comprising: a floor-engaging support including a hollow tube at the upper end thereof, a swivel seat mounting member carried by said tube in its upper end having an upper flange in part resting on and in part fitted within the upper end of said tube and a sleeve portion below said flange extending downwardly within the tube and having an externally threaded reduced portion at its lower end, said member having a bore extending vertically therethrough; an expandable gripping element mounted over said threaded portion and against a shoulder thereabove and having a plurality of radially extending projections tilted slightly downwardly from the horizontal and engaging the inner wall of the tube; a washer carried by said threaded portion below said element and in contact with said projections; and a nut on said threaded portion below said washer to hold said projections in their extended positions in locked engagement with the tube, thereby securing said member to the tube; and a seat assembly having bearing means rotatably carried on said mounting member flange and having :2. depending shaft extending through said bore.

5. A swivel seat comprising: a floor-engaging support including a hollow tube at the upper end thereof, a swivel seat mounting member carried by said tube in its upper end having an upper flange in part resting on and in part fitted within the upper end of said tube and a sleeve portion below said flange extending downwardly within the tube and having a threaded portion at its lower end, an expandable gripping element below said lower end and having a plurality of radially extending projections tilted slightly downwardly from the horizontal and en gaging the inner wall of the tube; a threaded fastener in mating engagement with said threaded portions and exerting a force on said projections to hold said projections in locked engagement with the tube, thereby securing said member to the tube; and a seat assembly having bearing means rotatably mounting said seat assembly to said mounting member.

6. A seat supporting structure, comprising: a floorengaging support including a uniform upwardly extending tube; and an adapter assembly carried in the upper and inner portions of said tube for adapting said tube to rotatably carry a seat thereabove consisting of an elongated body portion, a taper near its upper end for forming an interference fit between said body and the inner surface of said tube, a downwardly facing shoulder below said tapered portions, a threaded portion adjacent said shoulder, an expandable element having a central hole therethrough abutting said shoulder and having a plurality of outwardly extending angularly bent projec- .tions with end edges adapted to be pressed into locking 6 engagement with the inner wall of said tube, a threaded fastener screwably engaging said threaded portions and locking said expandable element to said body; and means for rotatably supporting a seat thereabove.

7. A swivel chair structure, comprising: a lower floorengaging support; a uniform tube forming a part of said support and extending substantially vertically upward therefrom; a member carried inside said tube at its upper end having a hole extending generally vertically therethrough and having means for centering and supporting it in said tube; a seat assembly mounted for rotation relative to said member and having a shaft depending downwardly from its middle. lower portions and extending through said hole, lower portions of said shaft being threaded and extending below the bottom of said member; gripping means fixedly locking said member to the inner wall of said tube; and other threaded means for engaging the threaded portions of said shaft and preventing said seat assembly from being lifted olf said tube.

8. A rotatable chair assembly, comprising: a supporting structure including an elongate upright tubular member; a seat mounting adapter mounted inside said tubular member including means for aligning said adapter in said tube; a compression element on the adapter having portions extending laterally into engagement with the inner surface of said tube for fixedly locking said adapter to said tube; means for creating compression in said compression element; means providing a vertical bore in said adapter; and a seat structure carried by said adapter including a depending shaft rotatably received in said bore.

9. A rotatable seat assembly comprising, in combinat-ion: a floor-engaging support including an upright hollow tube, a mounting device carried inside the tube at its upper end, said device having expandable means and means for expanding the same into contact with said hollow tube fixahly locking the device to the tube, a swivel seat rotatably carried by said mounting device, and cooperating means forming a part of said swivel seat and mounting device for biasing said swivel seat to a predetermined position relative to said support when said mounting device is locked to said tube.

10. In a swivel chair including an upright supporting tube and a seat thereabove, the improvement comprising: a mounting member mounted in the tube at its upper end to rotatably support said seat thereabove and including a hollow sleeve portion extending downwardly into said tube means for centering the mounting member in the tube, and means carried by the mounting member for locking the mounting member to the tube.

References Cited by the Examiner UNITED STATES PATENTS 1,870,833 8/ 1932 Burr 287-414- X 2,816,769 12/ 1957 Noble 2-87- 1 14 X 3,055,628 9/ 1962 Savage 248-417 3,107,891 10/ 1963 Burke 248-417 FOREIGN PATENTS Ad. 22,965 3/ 1921 France.

CLAUDE A. LE ROY, Primary Examiner,

Claims (1)

1. A SWIVEL SEAT CAPABLE OF RETURNING ITSELF TO A FORWARDLY FACING POSITION, COMPRISING: A FLOOR-ENGAGING SUPPORT INCLUDING A HOLLOW TUBE AT THE UPPER END THEREOF, A SWIVEL SEAT MOUNTING MEMBER CARRIED BY SAID TUBE IN ITS UPPER END HAVING AN UPPER FLANGE IN PART RESTING ON AND IN PART FITTED WITHIN THE UPPER END OF SAID TUBE, A SLEEVE PORTION BELOW SAID FLANGE EXTENDING DOWWARDLY WITHIN THE TUBE AND HAVING AN EXTERNALLY THREADED REDUCED PORTION AT ITS LOWER END, SAID MEMBER HAVING A BORE EXTENDING VERTICALLY THERETHROUG, AND A SUBSTANTIALLY VERTICAL HOLE OFFSET FROM SAID BORE AND OPENING UPWARDLY THROUGH THE FLANGE; AN EXPANDABLE GRIPPING ELEMENT MOUNTED OVER SAID THREADED PORTION AND AGAINST A SHOULDER THEREABOVE AND HAVING A PLURALITY OF RADIALLY EXTENDING PROJECTIONS TILTED SLIGHTLY DOWNWARDLY FROM THE HORIZONTAL AND ENGAGING THE INNER WALL OF THE TUBE; A WASHER CARRIED BY SAID THREADED PORTION BELOW SAID ELEMENT AND IN CONTACT WITH SAID PROJECTIONS; AND A NUT ON SAID THREADED PORTION BELOW SAID WASHER TO HOLD SAID PROJECTIONS IN THEIR EXTENDED POSITIONS IN LOCKED ENGAGEMENT WITH THE TUBE, THEREBY SECURING SAID MEMBER TO THE TUBE; A SEAT ASSEMBLY HAVING BEARING MEANS ROTATABLY CARRIED ON SAID MOUNTING MEMBER FLANGE AND HAVING A DEPENDING SHAFT EXTENDING THROUGH SAID BORE, SAID SHAFT HAVING A LOWER THREADED PORTION EXTENDING BELOW SAID MEMBER, A NUT ON THE LOWER THREADED PORTIONS OF SAID SHAFT FOR PREVENTING REMOVAL OF SAID SEAT ASSEMBLY FROM SAID MOUNTING MEMBER; SAID SEAT ASSEMBLY ALSO HAVING A GENERALLY DOWNWARDLY FACING AND ARCUATELY CURVED CAM SURFACE INCLINED IN A PLANE MAKING AN ACUTE ANGLE WITH THE HORIZONTAL; AND A COMPRESSION SPRING CARRIED IN SAID HOLE WITH A GENERALLY VERTICALLY BIASED FOLLOWER MEMBER THEREABOVE FOR EXERTING A FORCE AGAINST SAID CAM SURFACE AND BIASING SAID SEAT ASSEMBLY TOWARDS ITS FORWARDLY FACING POSITION.

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