Tilting chair

B. F. HAMILTON

TILTING CHAIR

Aug. 24, 1954

Filed April 4, 1S52

2,687,166

Sheets-Sheet 1

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Aug. 24, 1954 _{B F} Hamilton 2,687,166

TILTING CHAIR

Filed April 4, 1952 2 Sheets-Sheet 2

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BY

Patented Aug. 24, 1954

2,687,166

UNITED STATES PATENT OFFICE

2,687,166 TILTING CHAIR Bertis F. Hamilton, Columbus, Ind. Application April 4, 1952, Serial No. 280,499

Claims.

This invention relates to a type of chair- embodying a vertically adjustable seat mounted for rotation about a vertical axis and for, tilting movement about a horizontal axis and provided with a back adjustable fore and aft with respect to the seat. Chairs of this type are commonly used in offices.

It is an object of this invention to improve, simplify and cheapen the construction of such chairs especially with respect to the manner in which the seat is mounted for rotation about the vertical axis, to the. manner in which the seat is supported for tilting movement, and to the manner in which the back is supported for fore and aft adjustment relative to the seat.

In carrying out the invention in its preferred form I employ a seat pan, conveniently formed of sheet metal, and adapted for the application of any desired form of upholstery. To the underside of this seat pan I secure a reinforcing plate having pairs of struck-down ears provided with holes which slidably receive horizontal members of a back support. An additional pair of ears struck-down from the reinforcing- plate are pivotally connected at their lower ends to a bracket rotatably supported at the upper end of a vertically adjustable rod. The bracket has vertically spaced, horizontal walls provided with aligned openings rotatably receiving such rod; and between the walls there is secured to the- rod a thrust collar by means of which vertical forces are transmitted from the seat to the rod. A spring means acting between the bracket and the reinforcing plate opposes rearward tilting of the seat.

The accompanying drawings illustrate the invention; Fig. 1 is a side elevation of an office chair; Fig. 2 is a fragmental vertical section on the line 2—2 of Fig. 4; Fig. 3 is a bottom plan view of the chair-seat; and Fig. 4 is a generally vertical section on the line 4—4 of Fig. 2.

The chair illustrated comprises a base 10 in which a seat-supporting rod 11 is mounted for vertical adjustment. A releasable locking device 12 holds the rod 11 at any desired elevation. The present invention is not concerned with details of construction of the base 10 or of the locking device 12, the construction shown being one more fully illustrated and described in my copending patent application Serial No. 175,603, filed March 30, 1950.

The seat, which is rotatably mounted on the upper end of the vertically adjustable rod 11, comprises a seat pan i 5 desirably in the form of a sheet-metal stamping having a downwardly (Cl. 155—77) extending peripheral flange 16 the lower edge of which is turned inwardly to form a lip 17. The body portion of the seat pan IS is conveniently concave upwardly to receive padding 18 covered 5 with any convenient type of upholstery material 19 which extends downwardly over the outer surface of the flange 16 and inwardly around the lip 17.

Secured to the under surface of the seat pan 10 15 is a reinforcing plate 21 conveniently of a generally rectangular shape. Adjacent each side edge of such plate, pairs of front and rear tongues 22 and 23 are struck downwardly from the plate to occupy parallel planes extending transversely 15 of the seat. The pairs of front and rear tongues are provided with aligned holes for the reception respectively of horizontal portions 24 of a back-support 25 which, in rear of the seat, extends upwardly to. support a chair-back 26. Con20 veniently, the back-support 25 is a single length of metal tubing the ends of which extend through openings in the rear portion of the seat-flange 16 and constitute the horizontal portions 24 slidably received in the tongues 22 and 23. As 25 shown, the lower end of each of the front tongues 22 is bent to provide a horizontally extending ear 28 tapped for the reception of a set screw 29 by means of which the back-support can be locked in any desired position of fore and aft ad30 justment.

The seat is desirably supported at the upper end of the rod 11 through the medium of a bracket comprising upper and lower members 31 and 32 respectively. The members 31 and 32 are 35 desirably of relatively heavy sheet metal, and the member 32 is formed in a U-shape to provide at its sides upwardly extending parallel flanges 33 the upper ends of which are turned outwardly to form lips 34 secured to the lower 40 surface of the upper bracket member 31, as by rivets 35. The upper and lower bracket members 31 and 32 are provided with vertically aligned openings which receive the upper- end of the rod 11, and between such two bracket 15 members there lies a thrust collar 37 secured to the rod 11 as by means of a transverse pin or rivet 38. If desired, a bearing washer 39 may be interposed between the thrust collar 37 and each of the bracket members 31 and 32. To pro50 vide a more effective bearing and support on the rod 11, the upper and lower bracket members 31 and 32 may be formed with annular bearing flanges 40.

The seat is conveniently connected to the 55 bracket 31—32 by means of a pair of tongues 45

2,687,166 struck downwardly from the reinforcing plate 21 into spaced, vertical positions. The two tongues 45 overlie the flanges 33 of the bracket member 32 and are pivotally secured to such flanges by means of a horizontal pivot pin 46 extending through aligned openings in the tongues and bracket-flanges.

To oppose rearward tilting of the seat about the axis of the pivot pin 46, I may employ a compression spring 50 acting between a forward extension 51 of the upper bracket member 31 and a nut 52 mounted on the threaded lower end of a bolt 53 the upper end of which is connected to the seat. As shown, the reinforcing plate 21 has near its front edge a downwardly offset portion 54 providing clearance below the seat pan 15 for a head on the upper end of the bolt 53, and such bolt extends downwardly through generally aligned holes in the downwardly offset portion 54 and extension 51 of the upper bracket member. Tongues 56 (Figs. 3 and 4) struck downwardly from the extension 51 provide a seat for the upper end of the spring 50. The lower end of such spring may be received in a cup 59 slidable on the bolt 53 above the nut 52.

Forward swinging movement of the seat under the influence of the spring 56 may be limited by a stop screw 60 (Figs. 3 and 4) screw-threadedly supported from the bracket-member extension 51 in position to engage the reinforcing plate 21 near the front edge thereof.

The reinforcing plate 2! may be attached to the seat pan 15 in any desired manner. As shown, series of offset clips 62 are located along the front and rear edges of the reinforcing plate 21, each of such clips having two vertically offset portions, one of which underlies the reinforcing plate 21 and the other of which is secured to the seat pan 15 as by spot welding. To locate the reinforcing plate 21 transversely of the seat pan, I may employ angle members 63 each having one leg secured to the seat pan 15 by spot welding and another leg extending downwardly past the adjacent edge of the reinforcing plate 21.

It will be obvious from the above description that I have provided a seat and seat-supporting structure which, because it lends itself to sheetmetal construction, may be simply and economically manufactured. The seat may swivel about the axis of the vertical rod 11, being supported in such swiveling movement by the thrust collar 37 and the flanges 40. The seat may be tilted rearwardly about the axis of the pivot pin 46 in opposition to the force transmitted to the seat through the bolt 53 by the spring 50. The back 26 may be adjusted forwardly or rearwardly of the seat by sliding the horizontal portions 24 of the back-support in the ears 22 and 23. The set screws 29 lock the back-support in any desired position of fore-and-aft adjustment.