US2728379A - Chair back supporting and adjusting mechanism - Google Patents

Description

E. L. PERRY Dec. 27, 1955 CHAIR BACK SUPPORTING AND ADJUSTING MECHANISM Filed May 3, 1954 ELM/00D L. PEP/BY CHAIR BACK SUPPURTING AND ADJUSTlNG NIECHANISM Elwood L. Perry, Hickory,'N. C. Application May 3, 1954, Serial No. 427,260 Claims. (Cl. 155-456) The invention relates to chairs and similar articles of furniture having seats and backs, and it is more particularly concerned with improved mechanism for adjustably supporting the chair back.

One object of the invention is to provide mechanism of the above general character which permits angular adjustment of the chair back through a wide range, which is easily manipulable by a person sitting in the chair without rising therefrom, and which insures positive and rigid retention of the chair back in anyselected position of adjustment.

Another object is to provide chair back supporting and adjusting mechanism which is very sturdy, which is simple and reliable in operation and which can be manufactured at relatively low cost. I

Other objects and advantages of the invention will "become apparent from the following detailed description of the preferred embodiment illustratedin the accompanying drawing, in which:

Figure 1 is a side elevational 'view of a chair equipped with adjustable back supporting mechanism embodying the features of the invention.

Fig. 2 is a rear elevational view of the chair shown in Fig. 1.

Fig. 3 is -a sectional view taken in a'plane substantially on the line 33 of Fig. 1 showing the latch means in latching position.

Fig. 4 is a sectional view similarto Fig. ,3 showing the latch means actuated to release the chair back for.adjustment.

Fig. 5 is an exploded perspective view showing details of the latch means.

While a particular embodiment of the invention has been illustrated and will be described herein, it -is .not intended to limit the invention .to details of the particular form shown but, on the contrary, the intention is to cover all modifications and adaptations falling within the spirit and scope of the invention as e resse'd in the appended claims.

Referring to the drawing, the invention'has been shown as incorporated in an armchair for supportingthe back "B so that it may be angularly adjusted relative to the seat S. The exemplary chair has a frame comprising a .pair of side assemblies connected by crossmembers .11 which support the seat S, herein shown as'apad'orcushion 12. Additional cross braces 13 may be provided below "the seat support for strengthening the frame.

The side assembiles 10 are alike. As shown, eachcomprises a pair of upright supporting elements .or legs 14 joined at their upper ends by a top member 15 appropriately shaped to constitute an arm rest. Additional structural members 16 and 17 extend between the 'legs 14 below and spaced from the arm rest, those members in the present instance being parallel to the arm rest and rigidly attached to-the legs.

'The cha'irback B as showncomprisesa-pair'of side rails 18, a top rail '19 and a bottom rail 20 assembled and rigidly rjoined together to form a rectangular tramework.

tates PatentO This framework may be fitted with slats, webbing or other suitable structurewhic'h'inay constitute a back rest or may serveas a' supportfor"'a-removable backrest, such as a pad or cujshionZl. Aswill 'be seen .byrejference 'to Fig. '2o f the drawi g, the "back isdimensioned to fit between the'side assemblies 10 with suflicient clearance 'at each side to permit ittoswing freely.

In accordance with the invention, mechanism is pro vided for supporting the chair back B on the frame so that it may be swung about a transverse horizontal axis into selected angular positions with respect to the chair seatand securelyiatched "in any selected position "of adlong, fiat endportionsESand justment. The supporting mechanism in its preferred form includes a pair of elongated side bars 25 and .26 of "steel or other suitable material adapted to have the upper end portions rigidly attached to the side rails 18 of the chair back and to jgbe p'ivotajlly mounted on the chair frame. The mounting ispreferably effected through the medium of "brackets '27 fastened to the frame side assemblies 10 byscrew's .or other suitable fasteners.

The side bar 25, as shown, is formed with relatively 29 connected by an intermediate portion 30 bent at right angles to the end portions so that the latter are offset to lie-fin spacedparallel planes. The amount of offset .is suc'hithat when the end portion'28 is mounted :flush. against the side bar 18 of the chair back,the endportion'29 will extend along the outer side of the frame side assemblylt). For use with the particular 'chair'illustrated, the upper end ofthe side bar 25'is angled slightly'with respect to the lower ,end portion 50 that the chair back. slopes rearwardly when the lower end portion is approximately upright. The side bar 26 is substantially a duplicate of the bar 25 except that the lower endportion 29/ is somewhatshorter than thecorresponding portion of the companiouhar.

In the exemplary supportingmechanism, ,theside bars 25 and ,Zli'are ,p'ivotally eonnected to their respective brackets 27 below the transverse portions .30 of the bar h pi al c nn ction is provided by t a suitable pivot pin 31 which maybe in the form of va bolt or,rivet .the latter being Preferredsin eiit permitsthe ,parts to be permanently secured together asa unit, thus precluding ,their separation andloss'before installation.

The brackets 27 7 preferably have their intermediate .portions offset outwardly from .theends to afford clearance for the side ba s. The ends .of the brackets .aresuitably apertured ,for the accommodation .of the fasteners by which they are attaehed'to the .chair frame. .In the exemplary embodiment, .the brackets .are :disposed diagonally 'across the upper .rear corners of the frame ,side assembly .10 with their .ofisetrends attached respectively to .the arm .rest 15 and the rear .1eg..14. When :the arm rest '15 is relatively thick,-.as..sho.wn, it may be formed with a recess 32 .adjacent therear .leg.14tso as .to clear the intermediate portion of the side bar.

Attachment of the upper portionszsofthe side bars to .the .side mile 118 ofithetchair back B ,may be effected in any preferred ,manner. .As herein .shown, the .attaehment is by means .oftchannelrshaped :members 133 screwed or otherwise pennanently If stened to the side rails 18 -so as to define elongated-sockets for slidably receiving he end portion of .theibars. .AfterassfimblL theparts may be locked'in assembled relation by screws .34 inserted through apertures in the channels :and threaded ,into .the side lbars.

'The above described.mountingoflhechair.back B perrnits it to"be angularly adjusted .to the ,position most comfortable to the person sitting .inlhe chair and .without necessitating .rising from the chair. Theinvention also provides novel :latching means co-opera'ting withtthe supporting -struc'ture"for treleasably. retaining the chair backin any selected-position 'dfadjustment.

The latching means in its preferred form comprises an elonga ed latch bar 35 pivotally connected adjacent its rear end as at 36 with the extended lower end portion of the side bar 25 and extending forwardly therefrom as shown in Fig. l. Adjacent its forward end, the bar 35 has a series of longitudinally spaced latching apertures 37 adapted to be slipped over a stationarily supported latch pin 38 (Figs. 3-5) carried on the chair frame. As shown in Figs. 3 and 4, the pin 38 is rigidly fixed to a mounting plate 39 adapted to be secured by screws or other suitable fasteners to a suitable part of the chair frame, as for example, the intermediate member 16 of the frame side assembly 10. Each of the apertures 37 in the latch bar corresponds to a difierent angular position of the chair back and the engagement of the pin in any aperture serves to positively retain the back in the corresponding position.

To prevent accidental disengagement of the latch bar, the latch means includes means for yieldably retaining the bar in engagement with the latch pin, together with co-operating manually operable releasing means whereby the latch bar may be disengaged from the pin to permit adjustment of the chair back to a different position. The retaining and releasing means is desirably incorporated in a unitary structure so that there are no loose parts that can be mislaid or lost before or after assembly with the chair structure.

Referring to Figs. 3-5 of the drawing, the retaining and releasing means in its preferred form includes a plunger 40 supported in axial alinement with the pin 38 and urged by a spring 41 against the outer face of the bar 35. The plunger 40 is preferably formed with a head 42 for engagement with the bar and its shank portion is slidably received in an opening 43 in a stirrup-' shaped bracket 44 overlying the latch bar and the pin 38. As shown in Figs. 3 and 4, the bracket 44 is riveted or otherwise rigidly attached to the pin mounting plate 39 and the biasing spring 41 is interposed between the bracket and the plunger head 42.

The latch releasing means comprises a lifting cam 45 interposed between the mounting plate 39 and the latch bar 35 and rotatably supported on the latch pin 38 for limited rotation about the axis of the pin. Cam surfaces provided on the cam 45 arearranged for coaction with the bar 35 for shifting the bar axially of the locking pin to engage it with or disengage it from the pin. In the exemplary mechanism a hand lever 46 is provided on the cam for manual operation of the same, the hand lever being located for convenient access to a person sitting in the chair as will be seen by reference to Fig. 1.

In the preferred form shown, the lifting cam 45 is of cup-shape construction comprising a flat circular body member 47 with an integral upstanding rim 48 around its outer edge. The member 47 is centrally apertured to fit over the pin 38 which serves as a pivot about which the cam may be rotated. As will be seen by reference to Fig. 5, the rim 48 is cut away' or recessed at diametrically opposite sides of the body to define a channel for the reception of the bar 35 which, when disposed in the channel, lies flush against the outer face of the member 47. At one side of each recess, the rim terminates in an upright shoulder or abutment 49 engageable with the side of the bar 35 to define one limit position of the cam. This limit position is preferably such that the hand lever 46 extends substantially upright and is thus presented for easy manipulation by the occupant of the chair.

At the other side of each recess, the rim 48 is sloped upwardly from the member 47 to define an inclined cam surface 50 effective upon rotation of the cam to shift the bar outwardly against the force exerted by the spring 41. It will be understood that the height of the rim 48 is such that the bar 35 may be shifted far enough to disengage it from the pin 38.and thus free the bar so that it may be shifted endwise. The provision of the simultaneously acting cam surface 50 at opposite sides or the bar precludes cocking or skewing of the bar as it is lifted off the latch pin. Binding of the bar on the pin or at its connection with the side bar 25 is thus avoided and smooth and easy operation of the latch mechanism at all times is insured.

To facilitate adjustment of the chair back by a person sitting in the chair, provision is made for biasing theback to a substantially upright position. The biasing means preferably comprises a pair of coiled tensile springs 51 acting respectively between the side bars 25 and 26 andthe chair frame. As shown, each spring 51 is anchored at one end to the chair frame, in this instance, to the lower member 17 of the frame side assembly 10. At its other end, each spring is anchored to an arm 52 rigid with and projecting forwardly from the respective side bars 25 and 26 above their pivotal mounting on the chair frame. The arrangement is such that upon'release of the latch mechanism, the chair back B will automatically swing to an upright position unless opposed by force exerted on it by a person sitting in the chair. e

To change the position of the chair back, that is, to adjust it to a more nearly horizontal position, it is only necessary for the occupant of the chair to move the hand lever 46 to the latch releaseposition and then lean back in the chair until the chair back is pushed into the desired angular position. Upon release of the hand lever the latch mechanism automaticaly re-engages to hold the chair back securely and positively in the adjusted position. To adjust the chair back to a more upright position, the occupant of the chair first leans back to relieve the pressure of the latch bar on the latch pin 38. The hand lever 46 is then rocked to release position and, while held in such position, pressure on the chair back is gradually reduced. Springs 51 then act to swing the back toward upright position. Movement of the back can be interrupted at any desired point by simply releasing the hand lever to permit the latch mechanism to re-engage. It will be evident from the foregoing that the chair back adjusting mechanism provided by the present invention is extremely easy to manipulate. The mechanism is very sturdy and the construction is simple so that it can be manufactured at low cost. The mechanism is easy to install and it is readily applicable to a wide variety of chairs and similar articles of furniture equipped with adjustable backs. i

I claim as my invention: 1. The combination with a chair having a frame supporting a seat and back, of mechanism for adjustably supporting the back on the frame comprising, in combination, a pair of elongated side bars connectable respectively to opposite sides of the back, brackets adapted to be rigidly attached to the frame at opposite sides thereof, means pivotally connecting said side bars to the respective brackets to support the chair back for swinging about a transverse horizontal axis adjacent the rear of the chair frame and the lower end of the back, one of said side bars having its lower end portion extended a substantial distance below said axis, a latch bar pivoted at one end to the extended end of said side bar and projectingsaid pin, and cam means rotatable about the axis of said I pin to shift said latch bar axially along and out of en-.

gagement with said pin to thereby release the chair back for, adjustment to another position. 7

2. The combination with a chair having a frame supporting a seat and back, of mechanism for adjustably supporting the back on the frame comprising, in combination, a pair of elongated-side bars connectable respec tively to opposite sides of the back, brackets adapted to be rigidly attached to the frame at opposite sides thereof, means pivotally connecting said side bars to the respective brackets to support the chair back for swinging about a transverse horizontal axis adjacent the rear of the chair frame and the lower end of the back, one of said side bars having its lower end portion extended a substantial distance below said axis, a latch bar pivoted at one end to the extended end of said side bar and projecting forwardly therefrom along one side of the chair frame, a latch pin adapted to be mounted on the chair frame and projecting therefrom transversely of said latch bar, said latch bar having a series of apertures spaced apart longitudinally thereof for engagement selectively with said pin in different adjusted positions of the chair back, spring means yieldably urging said latch bar into engagement with said pin, a cam member supported for rotation on said pin, said cam member having a cam surface inclined with respect to said latch bar and coacting therewith when the cam member is rotated to shift the bar axially along the pin against the force exerted by said spring means and out of engagement with said pin, and a hand lever for rotating said cam member.

3. The combination with a chair having a seat frame and a back supported thereon for angular adjustment about a transverse horizontal axis adjacent the rear of the frame, of latch means for retaining the chair back in selected positions of adjustment comprising, a latch bar adapted to be connected to the chair back for endwise movement in a fore-and-aft direction as the chair back is adjusted from one position to another, a mounting plate adapted to be rigidly attached to the chair frame, a pin rigid with said plate and projecting therefrom transversely of said latch bar, said latch bar having a series of longitudinally spaced apertures for latching engagement with said pin, a bracket fixed to said plate so as to overlie said pin and said latch bar, means including a spring interposed between said bracket and said latch bar yieldably urging the latter into engagement with said pin, a cam member rotatably mounted on said pin between said plate and said latch bar, said cam having a recess accommodating said latch bar and permitting it to engage said pin, and an inclined cam surface at one side of said recess operative to shift said latch bar out of engagement with said pin upon rotation of said cam member, and a hand lever for rotating said cam member.

4. The combination with a chair having a seat frame and a back supported thereon for angular adjustment about a transverse horizontal axis adjacent the rear of the frame, of latch means for retaining the chair back in selected positions of adjustment comprising, a latch bar adapted to be connected to the chair back for endwise movement in a fore-and-aft direction as the chair back is adjusted from one position to another, a mounting plate adapted to be rigidly attached to the chair frame, a pin rigid with said plate and projecting therefrom transversely of said latch bar, said latch bar having a series of longitudinally spaced apertures for latching engagement with said pin, a bracket fixed to said plate so as to overlie said pin and said latch bar, means including a spring interposed between said bracket and said latch bar yieldably urging the latter into engagement with said pin,

cam means interposed between said plate and said latch bar for shifting the bar into and out of engaging relation to said pin, said cam means comprising a flat generally circular body centrally apertured for rotatable mounting on said pin, a rim upstanding from the edge of said body, said rim having recesses at diametrically opposite sides of said body dimensioned to receive said latch bar and allow it to lie in abutting relation to the body and in engagement with said pin, said rim at opposite sides of the respective recesses being formed to define an outwardly sloping cam surface upon which said latch bar rides into disengaged position with respect to said pin upon rotation of said body, and a hand lever for rotating said body.

5. The combination with a chair having a seat frame and a back supported thereon for angular adjustment about a transverse horizontal axis adjacent the rear of the frame, of latch means for retaining the chair back in selected positions of adjustment comprising, a latch bar adapted to be connected to the chair back for endwise movement in a fore-and-aft direction as the chair back is adjusted from one position to another, a mounting plate adapted to be rigidly attached to the chair frame, a pin rigid with said plate and projecting therefrom transversely of said latch bar, said latch bar having a series of longitudinally spaced apertures for latching engagement with said pin, a bracket fixed to said plate so as to overlie said pin and said latch bar, means including a spring interposed between said bracket and said latch bar yieldably urging the latter into engagement with said pin, cam means interposed between said plate and said latch bar for shifting the bar into and out of engaging relation to said pin, said cam means comprising a fiat generally circular body centrally apertured for rotatable mounting on said pin, a rim upstanding from the edge of said body, said rim having recesses at diametrically opposite sides of said body dimensioned to receive said latch bar and allow it to lie in abutting relation to the body and in engagement with said pin, said rim at opposite sides of the respective recesses being formed to define an out wardly sloping cam surface upon which said latch bar rides into disengaged position with respect to said pin upon rotation of said body, said cam surfaces having a slope such that the pressure exerted by said spring means through said latch bar is operative to turn said body into a position to aline the recesses with the latch bar, and manually operable means for rotating said body in a direction to cam said latch bar out of engagement with said pin.

References Cited in the file of this patent UNITED STATES PATENTS 298,065 Bush May 6, 1884 323,915 Collins Aug. 11, 1885 426,601 Muhl Apr. 29, 1890 1,173,075 Williamson Feb. 22, 1916 1,615,035 Rasmussen Jan. 18, 1927 1,821,298 Ferreira Sept. 1, 1931 1,893,128 Calvert Jan. 3, 1933 1,903,253 Austin Mar. 28, 1933 1,967,000 Van Derveer July 17, 1934

Images