US3439893A

US3439893A - Chair base

Info

Publication number: US3439893A
Application number: US594782A
Authority: US
Inventors: Kenneth N Paquette
Original assignee: Shaw Walker Co
Current assignee: Shaw Walker Co
Priority date: 1966-11-16
Filing date: 1966-11-16
Publication date: 1969-04-22
Anticipated expiration: 1986-04-22

Description

April 22, 1969 KQN. PAQUETTE CHAIR BASE Filed Nov. 16, 1966 ,W/JW Z Z7 8 f i 4 W 5 Unlted States Patent 3,439,893 CHAIR BASE Kenneth N. Paquette, Muskegon, Mich., assignor to The Shaw-Walker Company, Muskegon, Mich., a corporation of Michigan Filed Nov. 16, 1966, Ser. No. 594,782 Int. Cl. F16m 11/00, 13/00 U.S. Cl. 248405 1 Claim ABSTRACT OF THE DISCLOSURE A swivel chair base having a locking arrangement which permits assembly and disassembly and wherein the height of the chair is adjusted by manipulating a cylindrical sleeve which presents no outside irregularity and wherein a spring latch under ordinary circumstances holds the chair and base against vertical displacement while permitting free angular rotation.

Summary 07 the invention A base for a swivel chair seat, including a sleeve terminating at its upper end in an upwardly open, outwardly flared conical female bearing pocket, adapted to receive a conical male thrust bearing ring, a seat supporting screw slidably centered in the ring, a nut threaded on the screw, adapted to rest on the ring, an adjusting tube rigid on the nut adapted to enclose the bearing pocket, a latch spring fixed and enclosed in the tube projecting in wardly from the wall thereof, beyond the outer periphery of the pocket whereby upon downward assembly movement of the tube, screw and nut toward the pocket, the spring latch is compressed to permit seating of the nut on the bearing and as a result being below the pocket, yield ingly resists upward withdrawal of the nut, screw and tube.

Other objects will appear from time to time throughout the specification and claims.

The invention is illustrated more or less diagrammatically in the accompanying drawings, wherein FIGURE 1 is a side elevation in part section of the seat portion and the base in assembled working position;

FIGURE 2 is a detail elevation in part section on an enlarged scale showing the chair iron and base as they are about to be assembled;

FIGURE 3 is a similar elevation in part section showing the position of the parts as assembly continues;

FIGURE 4 is a plan view of the latch mechanism.

Like parts are indicated by like numerals throughout specification and drawings.

The chair iron 1 is the framework upon which the conventional type of seat adjustment is mounted for angu lar adjustment. The vertical downwardly depending adjusting screw 2 is rigidly attached to the chair iron 1 by the clamp 3. The cover tube 4 carried by the chair iron 1 extends downwardly therefrom and encircles the screw 2. An adjusting nut 5 threaded on the screw 2 carries the downwardly depending adjusting or nut rotating tube 6 which may telescope within the cover tube 4.

The nut 5 is radially grooved at 7 on its lower face to interlock with radial ridges 8 on the upper face of the annular, conical, male, nylon, thrust bearing ring 9. The screw 2 extends downwardly through the ring 9 into the base sleeve 10 which is conically flared at its upper end at 11 to define an upwardly disposed, female, bearing surface to receive the ring 9.

The base sleeve 10 is permanently mounted at its lower end on the base arms 12 so that with the parts in the position shown in FIGURE 1, the operator may rotate the adjusting tube 6 to rotate nut 5 to raise or lower it and the chair seat. The nylon ring 9 interlocking with the nut 5 is free to rotate in the female bearing surface 11 when the adjustment is made. In use, the chair seat may be turned in the usual manner. Turning the seat carries with it the screw, cover tube nut, adjusting tube and the bearing ring which all rotate in unison unless the adjusting tube is held manually against rotation.

The above description of the chair is necessary to provide a background for the particular invention here involved, namely-the hidden latch which makes it possible to assemble and disassemble the seat and base and which holds them together except when purposely disassembled.

The hidden latch includes a spring anchor 13 welded or otherwise attached at its ends to the inner wall of the adjusting sleeve 6 between its ends and spaced from the nut sleeve at 14 to form a pocket closed at the bottom by a lug 15 and recessed at 16. The pocket receives the lower end of a latch spring 17. A lug 18 pressed outwardly from the spring penetrates the recess 16. The latch spring is thus held in the position of FIGURE 2 with the central outwardly bowed portion thereof extending inwardly from the wall of the sleeve '5 a distance greater than the clearance between the flared end of the tube 10 and the sleeve wall.

As the seat and base portion of the chair are about to be assembled, the screw with the nut in the uppermost position are aligned with the base sleeve 10 and lowered into the position shown in FIGURE 2 with the latch spring extending inwardly above the thrust bearing 9 and the flared end 11. Further movement such as shown in FIG- URE 3 compresses the spring between the wall of the adjusting or nut tube and the flared end of the sleeve 10. Further movement brings the parts into the position shown in FIGURE 1 where the not 5 and the male bearing 8 interlock with the latch spring now below instead of above the flared support sleeve end. Downward movement of the latch spring is limited by contact of the end of the spring with the lug 15.

The strength of the latch spring and there might be, if desired, more than one is such that when the chair is lifted by holding on to the seat, the base comes along. Upward movement of the spring under those circumstances is prevented by penetration of the lug 18 into the recess 16, but if it is necessary to separate the base from the seat, all that is needed is to hold the base down, give a powerful jerk upwardly to the seat when the spring will be overcome in reverse direction and the parts will be separated.

The cover tube 4, the adjusting tube 6 and the fixed inner tube 19 on the base define a smooth walled cylindrical column like tubular shield to mask all the adjusting and working parts below the chair iron, thus lending themselves to a satisfactory stream-line design with the latch entirely masked.

I claim:

1. A vertically adjustable swivel chair, including a base, a seat assembly, a vertical screw permanently attached to the seat assembly, a base sleeve extending upwardly from the base, flared at its upper end to define an upwardly disposed, conical, female, thrust bearing surface, an annular, downwardly disposed, conical, male, thrust bearing ring, encircling the screw, adapted to penetrate the female bearing surface, a nut threaded on the screw, resting upon the bearing ring, an adjusting sleeve extending downwardly from the nut, latch means within the adjusting sleeve to yieldingly resist upward movement of the nut from the thrust bearing ring, said means including a latch leaf spring vertically disposed on the adjusting sleeve and extending inwardly from the inner Wall of the adjusting sleeve a distance greater than the clearance between the adjusting sleeve and the flared support sleeve, the lower end of the spring being socketed in a spring anchor on the inner wall of the adjusting sleeve which permits expansion and contraction of the sleeve but inhibits vertical longitudinal displacement thereof.

4 References Cited UNITED STATES PATENTS 3,059,888 10/1962 Lie 248-161 2,405,013 7/1946 Campbell 248408 2,999,665 9/1961 Ericson et al. 248-405 3,164,357 1/1965 Hage et a1. 248406 FOREIGN PATENTS 1,045,510 10/1966 Great Britain.

FRANCIS K. ZUGEL, Primary Examiner.

US. Cl. X.R. 248-159