US2272980A - Chair construction - Google Patents

Description

Fell 10, 1942- H. N. MCLELLAN ETAL C 2,272,980

' CHAIR CONSTRUCTION Filed Feb. 11, 1959 2 Sheets-Sheet 1 F1a. V.

INVENTORS. Hiram M9 Lellan BY Norman W. Taylor Q/M ATTORNEY 5'.

Feb. 10, 1942. H, N, McLi-:LLAN ETAL 2,272,980

CHAIR CONSTRUCTION Filed Feb. 11,A 1939 2* Sheets-Sheet 2 INVENTORL- Hiram N. MQLellan BY Norman W Taylor L WM ATTORNEY;

Patented Feb. 10, 1942 W. Taylor, Cleveland,Y Chio; said Taylor assignor to said McLellan f Application February 11, 1939, serialNo. 255,824rv (criss-77) This invention relates generally to chairs which are particularly suitable for mens executive oice chairs and stenographers chairs. One form of chair of this general character now in useembodies a seat which is rotatably mounted on a suitable base and has a back rest which is pivotally mounted and movable with respect to the seat, the back rest being hinged below the seat and swinging on a circular arc having a xed radius. In such a construction, the back,

rest is pivotally mounted below the seat at a point approximately six inches below the joint of the pelvic bone of a person seated in normal position in the chair. Such a back rest is uncomfortable and doesnot have the proper movement.

One of the objects of this invention is to provide a chair which consists essentially of a chair' base, a seat carried by the base and rotatably mounted thereon and an adjustable` backrest which is pivotally mounted so as to have a movement with respect to the seat substantially the same as the normal movementof the human back about the pelvic bone when seated in the chair in normal position, so that a person normally leaning back in the chair will be in a` relaxed position with the back comfortably supported.

Another object of the invention is to provide a chair seat construction and mounting therefor which includes a seat, a back rest pivotally mounted so as to move independently of the seat, together with means pivotally mounting and supporting said back rest andconstraining it to follow a path which will result in maximum comfort and relaxation.

Another object of the invention is to provide a chair of the character described which will overcome the difculties hereinbefore mentioned and which consists of relatively few parts; which are well adapted for production and assembly at a minimum cost.

A still further object of the'invention is to provide a chair of the character described which has a back rest which is pivotally mounted and movable with respect to the seatand which has at least three adjustments so that the chair may be adjusted t t the individual or the character of work being done. Y

A further feature of our improved chair resides in the fact that it has three adjustments, the first being an in-and-out or horizontal movement ofthe back rest with respect to the seat,v so that the back rest can be adjusted to` suit the individual with respect to his position in the able over a' range of nine inches at the top so *vide a chair having the above described dis- Fig. 1 is a view partly in section and partly in seat, the second being an up-and-down or verticalA adjustment which is required because no two individuals have the same shaped backs, and the third'being atilting adjustment of that part of theback rest which is disposed above the seat which is required because the particular type of work being done at the time determines the pitch of the back, for example: Aa ystenographer to support her back properly requires a back rest tilted forward much more than an executive -whose work is different and who normally assumes a diiierent position in the chair. In our improved construction the back rest has a maximum horizontal andv vertical adjustment of three inches and a tilting movement which is adjustthat the chair may be adjusted to properly t persons varying greately in height, weight and shape.

A still Vfurther objectV ofthe invention is to protinguishing and characteristic lfeatures and in which the 'chair seat and backrest are rotatably mounted as a unit'on a base, there being resilientv and adjustable means tending to re- 'sist the movement of the back rest about its axes.

Furtherl and more'limited objects will becomel apparent as the description proceeds 'and by reference to the accompanying drawings, in which elevation showing our improved chair as it'will appear when in one position; Fig. 2 is a horizontal sectionalv view on the line 2-2 of Fig. 1; Fig; 3 is a` fragmentary view in side elevation showing the opposite side of the chair from that seen' in Fig. 1 and" disclosing two positions of the back rest; Fig. 4 is a perspective View of the chair'rv seat and mounting therefor with parts removed to more clearly disclose the construction; and Fig. 5 is a perspective view showing one of the toggle links.

Referring now to the drawings, the reference character I designates the chair base which is supportedv uponsuitable casters and from which rises a columnor post 2 in which the chair seat issupported- Fitting within the column 2 and adjustably mounted thereon is a post 3 havingk afreduced end.. portion which receives thereover a bearing 4 which. is enclosed Within a suitable cover 5 which is attached to a chair seat supporting plate 6. The chair seat supporting plate B is somewhat U-shaped in section and has at each side thereofV a pair of downturned anges 1 and 8 each of which has therein a pair of straight parallel slots 9 and I 0, the purpose of which will hereinafter appear. Secured to the plate 6 are a pair of chair seat supporting arms II and I2 to which the chair seat proper I3 is secured. Pivotally and adjustably mounted on the plate 6 is a back rest supporting plate I4 which has a pair of downturned side flanges I5 and I6 each of which has therein an arcuate slot I'I, the purpose of which will hereinafter appear.

The plate I4 is pivotally secured to the anges 'I and 8 of the plate 6 by a pair of bolts I8 and I9 disposed at opposite sides thereof which bolts engage in the pair of straight slots 9 provided in the downturned flanges. It will thus be seen that the plate I4 is supported by and pivots about the bolts I8 and I9. Extending through the slots I and also through the pair of arcuate slots I'I in the downturned flanges I and I6 of the plate 6 are a pair of clamping bolts 20 and2| which are secured in place by a pair of clamping wheels 22 and 23. Disposed below the plate I4 and pivotally secured thereto is a back rest supporting member 24-which is preferably arcuate in shape and has the back rest proper secured thereto in a manner to be hereinafter described. The back rest supporting member 24 is secured to the plate I4 by a pair of links or arms 25 and 26, the link 26 being shown in perspective in Fig. 5. The link 25 is pivotally secured at its opposite ends by bolts 21 and 28 and the link 26 is secured at its opposite ends by bolts 29 and 30. The side walls I5 and I6 of the plate I4 have a pair of ears 3l and 32 cut out and bent inwardly therefrom, as shown in Fig. 2, each of which has an opening therein and through which extend a pair of bolts 33 and 34 which are preferably surrounded by a pair of rubber tubes 35 and 36. Fitting over the inner ends of the bolts 33 and 34 is a cross head 3`I which is secured in place by nuts 38 and 39. The arm 26 has on the outer face thereof a somewhat semi-circular depression 40 having an opening 4I therein. The cross head 31 is adjustably secured to the arm 26 by means of a bolt 42 and a nut 43 the opposite end of which is provided with a hand wheel 44. Disposed within the depression 40 is a circular pin 45 through which the bolt 42 extends. The side: iianges I5 and I6 have ears 46 and 41 cut out and bent upwardly therefrom, as shown in Fig. 2, which serve as stops to limit the rearward movement of the arm 26.

Carried by the upper end of the back rest supporting member 24 is the back rest proper which is indicated by the reference character 48 and which is shaped as shown most clearly in Fig. 4. 'I'he back rest 48 is pivotally secured to the back rest supporting member 24 by means of a pair of bolts or rivets 49 disposed at opposite sides thereof. The back rest 48 has a downwardly projecting portion 50 through which extends a bolt 5I having a T-shaped head 52 which is received in a depression provided in the portion 50. The bolt 5I extends through the arcuate supporting member 24 and threadedly receives thereover a hand wheel 53 which is rotatably secured to the member 24 and serves to adjust the pitch of the back rest. The hand wheel 53 engages in a keyhole slot 53a so as to permit assembly thereof. The back rest 48 is provided with suitable openings for receiving bolts therethrough and by means of which the wooden parts of the chair back proper may be secured in place. Substantially all of these parts may be formed of metal stampings of proper gauge to insure suiiicient rigidity of construction.

It will now be clear that the chair has three distinct controllable adjustments. The position of the back rest supporting member with respect to the seat may be adjusted in a horizontal plane in and out by sliding the back rest supporting plate I4, with respect to the seat supporting member 6, in the slots 9 and I0, the parts being clamped in the adjusted position by the hand wheels 22 and 23. The vertical position of the back rest with respect to the seat may be adjusted by swinging the member 24 which, by reason of the arcuate slots I'I, moves the plate I4 with respect to the plate 6. The hand wheels 22 and 23 likewise serve to secure the parts in this adjusted position. The pitch of the back rest 48 may be adjusted by turning the hand wheel 53 to turn the member about its pivots.

It will also be seen that the back rest is movable as a whole independent of these adjustments and swings about two xed axes, and that the path of travel of the back rest is such as to afford the maximum relaxation and comfort. The two xed axes are the bolts 28 and 30 and the two movable pivots are the bolts 2'I and 29. The seat and back rest are also rotatable on the post 3 as a unit.

In Fig. 3 the back rest supporting member 24 is shown in full lines in the upper position and in dot-and-dash lines in the position it will assume when a person is seated in the chair and leaning against the back rest. In Fig. 1 the parts are shown in the normal position with the chair unoccupied. When the back rest is moved rearwardly by a person leaning back in the chair, the member 24 swings on the- arms 25 and 26 and moves about two xed pivots and two movable pivots. The resilient rubber tubes tend to resist this motion and this resistance is adjustable by means of the hand wheel 44 which may be turned to place more or less tension on the rubber tubes. It is of course understood that spring means may be provided for this purpose, if desired.

It will now be clear that we have provided a chair seat construction and mounting therefor which will accomplish the objects of the invenf tion as hereinbefore stated. It is of course to be understood that the embodiment of the invention herein disclosed is to be considered merely as illustrative as various changes may be made in the details of construction and arrangement of parts without departing from the spirit of our invention and that the invention is limited only in accordance with the scope of the appended claims.

Having thus described our invention, what we claim is:

1. A chair comprising a base, a seat carried by said base, a member fixed with respect to said seat, a second member mounted on said first member and adjustable thereon in two directions, a back rest supporting member movable independent of said seat, and a pair of links pivotally securing said back rest supporting member to said second member.

2. A chair comprising a base, a seat carried by said base, a member xed with respect to said seat, a second member mounted on said first member and adjustable thereon in two directions, a back rest supporting member movable independent of said seat, a pair of links pivotally securing said back rest supporting member to said second member, a back rest pivotally secured said back rest carrying means including a back 10 rest supporting member, and link means connecting the same with said seat structure for movement about two axes iixed in relation to said seat structure and two pivots movable relative thereto, said back rest being hinged to said back rest supporting member, and means for adjusting the angular relation therebetween.

HIRAM N. MCLELLAN. NORMAN W. TAYLOR.

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