US 2673590 A
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March 30, 1954 TON 2,673,590
VERTICALLY ADJUSTABLE PEDESTAL CHAIR Fild July 24, 1950 3 Sheets-Sheet l INVENTOR. flaw/s EHHM/L row, BY
March 30, 1954 B. F. HAMILTON VERTICALLY ADJUSTABLE PEDESTAL CHAIR 3 Sheets-Sheet 2 Filed July 24, 1950 ENE Y5.
March 30, 1954 B. F. HAMILTON 2,673,590 VERTICALLY ADJUSTABLE PEDESTAL CHAIR Filed July 24, 1950 3 Sheets-Sheet 3 17 I J "r6 l I 43 i k I 44 INV EN TOR. 5597/5 fflfimw r01;
Patented Mar. 30, 1954 VERTICALLY ADJUST CHAI ABLE PEDESTAL R Bertis F. Hamilton, Columbus, Ind. Application July 24, 1950, Serial No. 175,603
This invention relates to chairs, and more particularly to office chairs having swiveled, vertically adjustable seats.
It is an object of the invention to produce a chair of the type indicated which will lend itself to construction with sheet-metal and metal tubing, which can be simply and economically manufactured, which will prove sturdy and durable in use, and which will possess a pleasing appearance. Another object of the invention is to facilitate the vertical adjustment of a chair seat. Still another object of the invention is to provide an improved means for adjusting a chairback horizontally with reference to the chairseat.
In carrying out the invention in the preferred form, I provide for the chair a base having a central, hollow housing formed of two complementary sheet-metal stampings. Desirably the base has four legs two of which are bolted to each of such stampings, and the two stampings are then bolted together to complete a stable chair-base. Extending through the housing is a vertical guide in which a seat-supporting rod is slidably received, and on the upper end of such rod the chair-seat is swiveled. To look the rod in any desired position of vertical adjustment it passes through a hole in a lock plate which is pivotally supported from the base on a horizontal axis offset from the rod, the arrangement being such that the downward load transmitted from the rod to the plate by frictional engagement will tend to cant the plate and increase friction between it and the rod. The chair-seat includes a cross-member having a pair of sheet-metal bearing supports in which is mounted a sleeve hearing rotatably receiving the upper end of the seat-supporting rod. A chair-back includes a back-support having two general horizontal, parallel arms which are slidably received in the aforesaid cross member, and means are provided for releasably holding such arms in any desired position of adjustment.
The accompanying drawings illustrate the invention: Fig. 1 is a front elevation of a chair in which the invention is embodied; Fig. 2 is a fragmental side elevation of the chair in partial section on the line 22 of Fig. 3; Fig. 3 is a horizontal section on the line 3-3 of Fig. 2; Fig. 4 is a fragmental horizontal section on the line i4 of Fig. 2; Fig. 5 is a vertical section on the line 5-5 of Fig. 4; Fig. 6 is a horizontal section on the line 6-5 of Fig. 5; and Fig. 7 is a fragmental vertical section on the line 1-1 of Fig. 1.
The chair illustrated in the drawing comprises a base having a central housing I 0 to Which radial legs ii are secured as by bolts I2. To increase the rigidity of the base and relieve the bolts l2 of strain, the legs Il may be interconnected intermediate their radial extent by a ring-like brace it.
As will be clear from Fig. 6, the housing I0 is formed of two complementary sheet-metal stampings having at their ends flanges I5 adapted to be clamped together by bolts I6. The legs H are desirably formed of metal tubing shaped at their inner ends to fit against and extend vertically along the outer surface of the housing Iii. Two legs are associated with each of the sheet-metal stampings constituting the housing 13, being secured thereto by the bolts I2. After the two legs associated with each housingstamp-ing are secured thereto, the two housinghalves are brought together in opposed relationship and secured together by the bolts IS.
The stampings constituting the housing Ill are provided at their upper and lower ends with vertically extending, coaxial semi-circular flanges I? which, when the housing is assembled embrace a vertical tubular guide l8 which slidably receives a seat-supporting rod l9. To 10- cate the guide I8 axially of itself in the housing It, it is provided at its ends with out-turned flanges which engage the ends of the flanges H.
The chair-seat see Fig. 2) desirably comprises a frame in the form of a sheet-metal stamping shaped to provide a generally horizontal floor 2! and an integral, downwardly extending, peripheral flange 22. Padding 23 for the seat is supported on the floor 2i and covered by a covering 2 of fabric or the like which extends down Wardly over the flange 22 and around the lower edge thereof.
The frame 2 l22 is supported on a cross member 25, which desirably is a box-like sheet-metal stamping having out-turned flanges 26 at the upper edges of its front and rear walls. The floor 2| rests on top of the cross member 25 and may be secured thereto through the medium of tongues 27 struck downwardly from the floor and embracing the outer edges of the flanges 23.
To the upper and lower sides of the bottom of the cross member 25 are secured oppositely disposed, dished bearing supports 3! conveniently formed as sheet-metal stampings and provided with peripheral flanges secured to the bottom. wall of the cross member by rivets 3 l. The bearing supports 33 are provided with aligned openings receiving a tubular member 32 in which a sleeve bearing 33 is in turn received. The upper end of the rod l9 extends through the sleeve bearing 33 to support the seat for rotation about the axis of the rod. The load on the seat is transmitted to the rod 19 through a collar 34 secured to the rod l9 as by a pin or rivet 35 and engageable with the flanged lower end of the sleeve bearing 33. A pin 36 extending through the upper end of the rod l9 above the upper end of the sleeve bearing 33. prevents removal of the seat from the rod.
To hold the rod IS in any position of vertical adjustment in the base, and hence to hold the chair-seat at any desired elevation, I employ the clamp means illustrated in Figs. 4 and 5. Such means comprises a clamp plate 40 desirably formed of sheet metal and provided with a hole which receives the rod l9 and which is of slightly larger diameter than such rod. At one end, the material of the plate 40 is bent back on itseli'to provide a flange 4| spaced from the body of the plate and adapted to support the plate in rocking relationship on the. upper end of the housing Hi. Atlits. center, the flange 4| is provided with a notch received beneath the head 42 of a bolt v43 which extends downwardly throughthe upper wall of the housing 10 into the interior of such housing, where it is surrounded by a compression spring 44 acting between the upper housing-wall and a nut 45 on the lower end of the bolt. As will be obvious from Fig. 5, the parts just described are so arranged that the spring 44, acting through the bolt 43, will tend to rock the plate 4llabout the point of contact between the flange 4|- and the upper wall of the housing Hi, the rocking tendency being in a direction which would move downward that portion of the plate 40 containing the hole through which the rod I9 passes. The construction is further such that the. spring 44 is capable of canting the plate 40 to an extent limited only by the binding of its hole with the rod l9.
Normally, the spring 44 holds the plate 40 in the position indicated in Fig. 5, in which the plate 40' is canted to bring the edges of its hole into gripping engagement with the rod l9. Downward load on the rod tends to increase canting of the plate 40 and hence to increase the binding or gripping effect of such plate on the rod. To release the rod I9 for vertical adjustment of the seat, the plate 40 is swung in a clockwise direction against the force exerted by the spring 44 until it occupies a position more nearly normal to the axis of the rod l9, when the rod I9 will be freely slidable through the hole in the plate. To facilitate this manipulation of the plate, it may be provided with an extension 46 which projects outwardly far enough to be manipulated by one or more fingers of a hand grasping the seat.
The chair shown in the drawings comprises a back support 50 to which a back of any desired type is secured in any convenient manner. The support 50 is desirably a length of metal tubing bent into a general inverted. U-shape and having its lower end portions 52 bent to extend forwardly in parallel relation. The horizontal portions 52 of the back support 50 extend through appropriately positioned holes in the rear side of the flange 22 and also through pairs of aligned holes in the front and rear walls of the cross member 25. The horizontally extending portions 52 are slidable in the holes which receive them, thus permitting, the back .5| to be adjusted. forwardly and. rearwardly or the, seat. To holdthe' back support in. any desired position of fore, and aft adjustment, I may employ set screws 53 which extend through the bottom of the cross member 25 into clamping engagement with the back-support portions 52.
In assembling the chair described, the legs II are attached to the two halves of the housing I0 by the bolts l2, the bolt 43 and spring 44 are assembled with the one half of the housing I0, and the housing-halves are clamped together by the bolts It, the tubular guide I8 being inserted between the two housing-halves to be clamped in. position by tightening of the bolts Hi. The two bearing supports 30 are secured to the cross member 25, the sleeve bearing 33 is put in place, the rod IS with the collar 34 secured to it is inserted into the sleeve bearing from below, and the pin 36 is put in place to prevent withdrawal of the rod. The stamping 2|-22 with the tongues 21 bent downwardly to clear the flanges 26, is positioned on the cross member, and the tongues 21 are then bent into the positionsshown in Fig. 2 to embracethe edges of the flanges 25 and secure the seat and cross-member 25 together. The upholstery may be applied to the seat either before or after its, assembly with the crossmember 25.
When the seat and base. sub-assemblies are to be united, the head 42 of the bolt 43 is elevated against the force of the spring 44, and the notched flange 4| of the clamp plate 40 is inserted beneath the bolt head. With the plate-extension 46 held elevated to bring the body of the plate 40 into a position approximately normal with the axis of the guide l8, the rod I9 is lowered through the hole in the plate and through the guide l8 until its lower end projects below the bottom of the guide l8. To prevent inadvertent separation of the seat and base sub-assemblies, a transverse pin 55 (Fig. 2) may be mounted in the lower end of the rod l9 with its ends projecting therefrom. If desired, the housing [0 may be provided with a tubular extension 56 secured in any convenient way to the lower housing-flanges IT and extending downwardly to conceal the lower end of the rod l9 and the pin 55 therein.
The back and back support may be mounted on the seat either before or after the seat is applied to the base. In mounting the back support on the seat, the horizontal portions 52 of the support are passed forwardly through the holes in the rear side of the seat-flange 22 and through the aligned openings in the front and rear walls of the cross member 25. A transverse pin 58, similar to the pin 55, may be provided in each of the horizontal portions 52 of the back support to prevent inadvertent withdrawal thereof from the cross member.
After assembly of the seatand base, the spring 44 acts as above described to cant the plate 40 away from a position of perpendicularity with respect to the rod I9, whereby to cause theedges of the hole in the plate to grip the rod frictionally and thus support the weight of the seat. When a load is applied to the seat, the downward force transmitted to the plate 40 from, the rod l3 tends to cant the plate even further, thus increasing the rod-gripping tendency. When it is desired to change the elevation of the seat, the occupant of the chair grasps the edges of the seat on each side with a finger of one hand disposed beneath the plate-extension 4.6; With the seat temporarily relieved of load, the plate-extension 46 is raised by the finger engagingit tobring. the body, of the plate into a substantially horizontal position, thus permitting free vertical movement of the rod I 9 and adjustment of the seat to the desired elevation. When the seat has been brought to the desired elevation, the plate-extension 46 is released, thus permitting the spring M to swing the plate 40 into a position where it grips the rod I9.
I claim as my invention:
1. In a chair of the type described, a base having an upper wall, a vertical rod slidable longitudinally of itself in said base, a seat mounted on said rod above the base, and a lock member rockably resting on said upper wall for swinging movement about a horizontal axis spaced laterally from said rod, said lock member having a rod-receiving opening slightly larger than said rod whereby the rod may slide freely in the opening when the axes of the rod and opening are coincident, said lock member being downwardly swingable to cause the edges of the opening to grip the rod, said wall having an opening, a tension member extending through said opening and connected to said lock member between the rod and the point at which the lock mem ber engages said wall, and a coiled compression spring located below said wall and acting between it and said tension member to urge the latter downwardly.
2. In a chair of the type described, a base comprising a vertically split, two-part, hollow housing having upper and lower end walls, radial legs having inner ends extending upwardly along the sides of said housing, a vertical tubular guide extending axially through said housing, means securing said inner leg-ends to the housing, means for clamping the two housing-parts together about said guide, a rod vertically slidable in said guide, a seat on the upper end of said rod, releasable lock means supported from said housing for holding said rod in fixed axial position, and a spring disposed inside said housing and urging said lock means to operative position.
3. The invention set forth in claim 2 with the addition that said lock means comprises a lock member having a downwardly retroverted end portion resting on the upper wall of said housing,
said member having an opening in which said rod is received, said member being rockable downwardly about the point of engagement between its end portion and the upper housing wall to cause the edges of the opening to grip the rod, said end portion and upper housing-wall being provided with aligned openings, and a bolt extending through said openings, said spring being a helical compression spring surrounding said bolt.
4. In a chair of the type described, a base, a vertical rod slidable longitudinally of itself in said base, a seat mounted on said rod above the base, a lock member having an opening receiving said rod, said member having a downwardly retroverted end portion engaging said base at a point spaced from said rod and being downwardly rockable about such point to cause the edges of the opening to grip the rod, said end portion being provided with an opening between the rod and the point at which it engages the base, and a rigid element extending generally vertically through said second opening and into the base for preventing said member from rotating relative to the base about the axis of said rod.
5. The invention set forth in claim 4 with the addition of a compression spring acting between said rigid element and said base and to urge said member downwardly.
BERTIS F. HAMILTON.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 836,303 Christensen Nov. 20, 1906 1,578,784 Walton Mar. 30, 1 26 1,606,840 Koenigkramer Nov. 16, 1926 1,674,081 Adams June 19, 1928 1,691,035 Adams Nov. 13, 1928 1,997,486 Hallowell Apr. 1935 2,392,477 Holm Jan. 8, 1946 2,432,245 Lundquist Dec. 9, 1947 2,454,057 Grunwald Nov. 16, 1948 2,529,780 Miller Nov. 1 1950