US3785700A

US3785700A - Chair

Info

Publication number: US3785700A
Application number: US00230256A
Authority: US
Inventors: S Kubo
Original assignee: KUBO SHOTEN KK
Current assignee: KUBO SHOTEN KK
Priority date: 1971-03-26
Filing date: 1972-02-29
Publication date: 1974-01-15
Anticipated expiration: 1991-01-15
Also published as: JPS5014585B1; AU466250B2; CA987578A; GB1330802A; SE370854B; AU3972472A

Abstract

A chair seat which is connected to a support leg through connecting means and free to be moved backwardly and rotated about said support leg and designed for automatic restoration to its former position, which is characterized in that an elongated resilient means acting linearly between the seat and the connecting means operates to control the backward movement of the seat and another elongated resilient means which is adapted to act angularly between the connecting means and the support leg operates to control the rotation of the seat.

Description

United States Patent [191 11] 3,705,700 Kubo Jan. 15, R974 [54] CHAIR 1,903,267 3/1933 Roberts 248/417 2,409,114 l0/l946' Elleman et al.. 248/417 UX [75] Invent sh'mhel Kulm Japan 3,637,185 1/1972 Mikos et al. 248/417 [73] Assignee: Kabushiki-Kaisha Kubo Shoten,

Tokyo, Japa Primary Examiner-Paul R. Gilliam [22] Filed: Feb. 29, 1972 Attorney-Schlesinger, Fitzsimmons & Schlesinger 7 [2!] Appl. No.: 230,256

[57] ABSTRACT [30] F i A li ti P i it D t A chair seat which is connected to a support leg Mar. 26 1971 Japan 46/17772 thmugh cmmwng means and free be "mved back wardly and rotated about said support leg and de- [52] US Cl 297/349 297/383 108/140 signed for automatic restoration to its former position, 248/417 which is characterized in that an elongated resilient 51 int. Cl. B60n 1/02, Fl6m 13/00 means acting nearly between the S and the [58] Field of Search 297/349 383' wing means Operates the backward 248/417425. g movement of the seat and another elongated resilient means which is adapted to act angularly between the [56] References Cited connecting means and the support leg operates to con- UNITED STATES PATENTS trol the rotation of the seat.

2,755,842 7/1956 Caramelli 248/417 UX 2 Claims, 7 Drawing Figures PAIENHUJANISBM 7 3 785 700 SHEET l} UF I CHAIR This invention relates to a chair which can be moved backwardly with respect to its support leg or revolved about its support leg and returned to its former position automatically and without the necessity of any particular manipulation. Backward movement and revolution of the chair can be obtained when a person seated on this chair applies his foot pressure to the floor surface or twists his body. Thus, a person seated on this chair can take anything around and behind him without any particular effort, or have a chat with others behind him.

A preferred embodiment of this invention will be explained in detail hereinbelow by referring to the accompanying drawings, in which:

FIG. 1 is a side elevation of a chair according to the present invention;

FIG. 2 is a plan view thereof, in which a part of seat is cut out;

FIG. 3 is a partially broken bottom view of substantial mechanical parts thereof;

FIG. 4 is a cross section taken on the line IV IV of FIG. 3;

FIG. 5 is a cross section taken on the line V V of FIG. 3 and shown with its frame plate removed from FIG. 3;

FIG. 6 is an enlarged longitudinal sectional view of substantial parts illustrated in FIG. 5; and

FIG. 7 is an enlarged bottom view of substantial parts of the chair, shown in FIG. 3.

A generally denotes a seat for a sofa-like chair having a chassis 6 fixed to its underside. A movable frame 2 rectangular form is fixedly accommodated within the chassis 6, so as to open towards the underside. The longitudinal sides of the guideframe 2 are formed with guide rails 20, 2b having both upper and lower rail faces. On either sides of a support I housed within said movable frame 2, there are provided three wheels 3 for rolling on the upper rail faces of the

guide rails

2a, 2b. Peripheral lugs 7a (FIG. 6) of a circular support plate 7 are secured to the inner upper surface of the support 1. Ball grooves 9 are formed on said support plate 7 on the circumference of a circle concentric therewith and so as to open towards the underside.

A support leg B for the chair has a support plate 10 (FIG. 1) at its lower end and a top part 4 to which a plate 5 having a substantially similar shape to said circular support plate 7 is secured at its lug parts 5a by bolts 8'. Ball grooves 11 are formed on said plate 5 on the circumference of a circle concentric therewith and so as to open towards the upper side. Six balls or rollers D fitted into retainers 12 are inserted for free rolling motion into spherical recesses defined by said ball grooves 9 on said support plate 7 and said ball grooves 11 on said plate 5. A bolt 13 is mounted to said support 1 as a center shaft for said circular support plate 7 and said plate 5. A nut 13 is threaded to said bolt 13 from the lower side of the plate 5.

C, C (FIG. 3) denote cables having sufficient elasticity and engaging at their both ends C1, C2 to a front plate la of the support 1 and a rear plate 2c of the frame 2 which is fixed to the seat A through the chassis 6 and movable with respect to the chair leg B being guided by the support 1 through the wheels 3. A further cable C having likewise a sufficient elasticity is engaged at both ends to the front plate 1a of the support 1, said cable C is coiled around circular grooves 14 (FIG. 6) formed on the outer circumferential surface of the

plates

7 and 5 and secured at its center to the outer surface of the plate 5 by mounting members 15 (FIGS. 3 and 7). l6 denotes a rubber stopper.

It should be noted that the cables C, C could each be a single cable or more than two. Though in the embodiment illustrated in the drawing and explained above with reference to the drawing, the cable C is a continuous single piece encircling around the circular grooves 14 and fixed at its both ends to the support 1, it should be noted also that said cable C could consist of a pair of cables of equal length each having one end fixed to the support 1 and another end fixed to the plate 5 independently of the other cable after partially encircling the grooves 14.

When a person seated on the seat A having the above-mentioned construction and, with the support leg B firmly placed on the floor, applies his foot pressure on the floor surface, for urging the chair seat A to be moved backward in the direction indicated by the arrow mark (X) (FIG. 2), the chair seat A is moved in said direction. More particularly, the movable frame 2 is moved, along with chair seat A and chassis 6, in the direction of the arrow mark (X) against the resiliency of the cables C, C, the

rollers

3, 3 then rolling on the guide rails 2a, 212 formed on the movable frame 2 so as to make the backward movement of the movable frame smooth. When the force acting in the direction of the arrow mark (X), that is, foot pressure applied on the floor surface, is released, the movable frame 2 will be moved, together with chair seat A and chassis 6, back to its former position or in a direction reverse to that shown by the arrow mark (X), under the recoiling force of the cables C, C.

When a person seated on the chair twists his body for partial rotation of the chair seat A in the direction shown by the arrow mark (Y) (FIG. 7), in either direction, the support 1 along with the plate 7 and the movable frame 2 will be revolved partially as a unit. It will be realized readily that a smooth revolution of the moving members is enabled at this time-because of balls D (FIG. 6) interposed between the stationary plate 5 and the circular support plate 7 which is forced into revolution concurrently with chair seat A, one of the cables C is subjected at this time to a tractive effort and elongated resiliently, while the remaining one C' is idle and out of operation. When the rotatory effort applied to the chair seat is released, the chair seat A will in a reverse direction, under the recoiling force of the cable C, and be restored to its former position.

When both rotatory and backward effort are applied to the chair seat A, in an intention to rotate and move it backward concurrently, both the cables C, C are elongated simultaneously, with the result that the clastic recoiling force is accumulated in said cables C, C. Thus, upon releasing the effort applied to chair seat A, the latter will be returned to its former position, the for ward movement and reverse rotation of the chair seat A then taking place concurrently. In the present embodiment of the invention, cables composed of strands of rubber and fiber etc. with sufficient strength and resiliency are used for producing resilient tractive force, but they can also be replaced by coil springs, other elastic filaments or other elongated resilient means without departing from the scope of the invention.

According to the present invention, as above described, the movable frame 2 for chair seat A in the form of a rectangular frame movably supported by support 1 therein is free to slide linearly backwards through a plurality of rollers 3, since at least one cable C with sufficient resiliency connects said support 1 and movable frame 2. On the other hand, the plate 5 secured to the upper part 5 of the support leg B is stationary relative to said support 1 which is rotatable with respect to the leg B through rollers D, since at least one cable C with sufficient resiliency works between said plate 5 and support 1. Thus, when desired to move the chair seat A, a light sliding movement will be brought about by virtue of rollers 3 interposed between the support 1 and the movable frame 2. The chair seat A thus moved backward can be returned to its former position smoothly and automatically under the recoiling force of the cable C which has been elongated with the backward movement of the chair seat A. Further, the chair seat A revolved partially can be restored to its former position smoothly and simultaneously under the recoil force of the cable C. In addition, the chair seat A can be revolved partially at the same time that it is moved backward and the chair seat A can be returned to its former position under simultaneous operation of the cables C, C. The construction of the present chair is highly simplified by virtue of provision of the resilient cables C, C.

In execution of the present invention, a plurality of cables C can also be utilized, while the cables C can be secured to any other positions than those specified in the present embodiment, at the manufacturers option.

What is claimed is: 1. A chair in which the seat is free to be simultaneously moved linearly backwardly from a forward position of rest and rotated about its support leg, and designed for automatic restoration to its rest position, comprising a movable frame member for the chair seat in the form of a rectangular frame,

a support member slidably fitted in said frame,

a plurality of rollers slidably supporting said frame member in a fixed plane on said support member,

at least one resilient cable placed intermediate said support member and said movable frame member and constantly urging said frame member linearly to rest position,

a plate secured to the upper part of the support leg,

means mounting said support member on said plate to rotate about the axis of said leg, and

at least one other resilient cable placed intermediate said plate and said support member and constantly urging said support member angularly about said axis to an angular rest position.

2. A swivel chair, comprising a seat,

a stationary leg,

an elongate frame member fixed to the underside of said seat,

a first support member fixed on said leg,

a second support member rotatably mounted on said first support member and secured against axial movement relative thereto,

means slidably mounting said frame member on said second support member for rotation therewith and for longitudinal reciprocation thereon in a fixed plane that extends transverse to said leg,

first elongate resilient means normally biasing said frame member forwardly to a first limit position on said second support member, and permitting said frame member to be slid rearwardly on said second support member upon exertion of a backward force through said seat to said frame member, and

second elongate resilient means connecting said second support member to said leg and normally resiliently resisting the rotation of the last-named member out of a position of rest on said first support member, and permitting rotation of said lastnamed member upon execution thereon of a turning moment through said seat,

said mounting means including means permitting simultaneous linear movement of said frame member and angular movement of said second support, I

wherein said support member comprises a pair of circular plates having a plurality of ball bearings interposed therebetween, and

said second resilient means comprises a resilient cable seated intermediate its ends in a circumferential groove formed between the confronting, marginal peripheral surfaces of said plates, and fastened at opposite ends to one of said plates and intermediate its ends to the other of said plates.

Claims

1. A chair in which the seat is free to be simultaneously moved linearly backwardly from a forward position of rest and rotated about its support leg, and designed for automatic restoration to its rest position, comprising a movable frame member for the chair seat in the form of a rectangular frame, a support member slidably fitted in said frame, a plurality of rollers slidably supporting said frame member in a fixed plane on said support member, at least one resilient cable placed intermediate said support member and said movable frame member and constantly urging said frame member linearly to rest position, a plate secured to the upper part of the support leg, means mounting said support member on said plate to rotate about the axis of said leg, and at least one other resilient cable placed intermediate said plate and said support member and constantly urging said support member angularly about said axis to an angular rest position.

2. A swivel chair, comprising a seat, a stationary leg, an elongate frame member fixed to the underside of said seat, a first support member fixed on said leg, a second support member rotatably mounted on said first support member and secured against axial movement relative thereto, means slidably mounting said frame member on said second support member for rotation therewith and for longitudinal reciprocation thereon in a fixed plane that extends transverse to said leg, first elongate resilient means normally biasing said frame member forwardly to a first limit position on said second support member, and permitting said frame member to be slid rearwardly on said second support member upon exertion of a backward force through said seat to said frame member, and second elongate resilient means connecting said second support member to said leg and normally resiliently resisting the rotation of the last-named member out of a position of rest on said first support member, and permitting rotation of said last-named member upon execution thereon of a turning moment through said seat, said mounting means including mEans permitting simultaneous linear movement of said frame member and angular movement of said second support, wherein said support member comprises a pair of circular plates having a plurality of ball bearings interposed therebetween, and said second resilient means comprises a resilient cable seated intermediate its ends in a circumferential groove formed between the confronting, marginal peripheral surfaces of said plates, and fastened at opposite ends to one of said plates and intermediate its ends to the other of said plates.