US2792876A

US2792876A - Reclinable chair construction

Info

Publication number: US2792876A
Application number: US554667A
Authority: US
Inventors: Robert J Emary
Original assignee: COLSON CORP
Current assignee: COLSON CORP
Priority date: 1955-12-22
Filing date: 1955-12-22
Publication date: 1957-05-21
Anticipated expiration: 1974-05-21

Description

May 21, 1957 R. J. EMARY RECLINABLE CHAIR CONSTRUCTION Filed Dec. 22, 1955 INVENTOR. 05597 J EMA/Q) ATTORA/Efi RECLINABLE CHAER QQNSTRUCTFON RbbertJ; Emary, Elyria, Ohio, assignor to The (Poison Corporation, Elyria, Ohio, a corporation of Ohio ApplicationDecembe'r 22, IJSQSeriaINo. 554,667

7 (Ilaims. (Cl; 155-453) This invention relatesto adjustably reclinable' backs for chairs and particularly to an improved adjustably reclinable back assembly for foldableor collapsible chairs or wheel chairs.

The comfort of an occupant of a wheel chair, especially an invali dlwho may remain inthe chair foi' long periods, oftenis improved if the occupant can assume various-reclined positions in the chair with his back fully supported as with anadjustablyreclinable back rest. Prior practices Qfadjustingthe angle of recline of the backrestsof chairs have failedto solve the problems peculiar to folding chairs or. folding wheel chairs, either because of comprising mechanism incompatible with folding the chair, orfailing in. strength, facility or security if modified to permit the chair'to be folded. Similarly, the utility of a folding chair depends on the facility with which it can be handled andstoredor transported in its folded condition and on its lightness and compactness when folded, as well as its strengtharid dependabilitywhenopened for use. My invention.preserves theutility of the folding chair and provides an adjustable reclining. back rest compatible therewith and with it the added comfort and convenience of the user of the chair.

A generalobject of my invention isthe provision of a reclinable back rest which readily isv adjust-able to a plurality of recline-angles andwhich is especially useful with foldingchairs Another object is the provision ofa reclinable back rest having self-contained; substantially fully? enclosed and reliable, foolproof adjustment mech anism. Another object-is the provision of a reclinable backrest, the design of which is easily. incorporated into existing designs. of folding. chairs and wheel chairs. A further objectis" the provision ofa reclinable backrest assembly. for chairs whichlcan be mounted-on the rear of a chair without substantial modification of the forward and und'er parts of the' chair. A more specific object'is theprovision of tubular re'clinable back rest members for chairs in which the mechanism for limiting the angle -of incline of the members is carried withinthe members. Still another-object is the provision of-an adjustable "back restassemblythat is positively. lockable in a fixed position at each ofseveral angles of recline. A 'further object is the provision of -a reclinableback rest embodying a compact operating mechanism that is durable, .economical sturdy and efiicient, andwhich is especially compatible with folding chairs.

These and other objects of my invention 'will become apparent from the-following description ofa'preferr'ed embodimentthereof; which for the sakeiof illustration, but not by way of limitation, comprises my invention in and in the environment of afolding wheel-chair; reference being had to the accompanying-drawings in which:

Figure l is "aside elevation of 'awheel chair having a reclinable back re'sfembodying my invention Figure 3 is an enlargedelevatiorial viewof the 'rear 2,792,876 Fatented May 21, 195? 2 part of the chair of Figure l, the wheel having been omitted for clearness of the drawing.

Figure 4 is an enlarged fragmentary elevational view, partly in section, of the back rest showing the details of tlie'operating mechanism. H

Figure 5 is an enlarged transverse section showing the releasable locking pin for holding the backrest in adjusted positions, the section being taken on line 5-5 of Figure 3i Figure 6' is an enlarged transverse section taken on line 6-6 of Figure 4. V v

Referringnow' to the drawings, a preferred embodiment of my invention is illustrated therein in a folding wheel chair having laterally spaced side frames F, each comprising front and rear upright members 12-and 13, respectively, connected by a longitudinally extending bottom mer'nber14, an intermediate seat bar 15 on which the outer side of a folding seat S is supported, and an upper arm rest'b'ar' which carries an arm rest A. In the following description and claims, the term front refers tothe right end of the chair as viewed in Figure 1', and rear refers to'the'left end of the chair as so viewed.

The lower central parts of theside frames F may be connected X-braces 17 and 13, each of which'extends diagonally between a pivotal connection to the underside of a seat bar on one side frame and a swivel connection with the bottoni member on theopposite side frame, the X braces serving to guidernovenient of the side frames toward and awayfrom each other while folding or collapsingthe' chair, as well as to raise and lower the folding seat sections when the chair isc ollapsedand extended; The front part ofeach-side frame conventionally has a footrest R and a caster C on thehumped up'po'rtion of each bottom member 14. A wheel W is mounted at the rear on the lower part of each rear upright frame member lll. Compatible with my invention,-the upper end of rear frame member 13 is terminated at T slightly above arm rest bar 16, see Figure 3.

The back rest assembly20, to which the present invention is directed, supports the'back of the chair occupant and extends upwardly from about the level of seat S higher than the arm rests and is pivotally mounted on each of the chair sideframes directly behind rear frame members 13 at the points 3234 at about seat level on rearwardly disposed supporting structures presently to' be described; The back rest assembly is arranged to pivot forwardly and rearwardly about a horizontal axis at approximately the level of the seat S between an up position in which the plane of the back rest preferably is slightly inclined rea'rwardly from vertical, as shown in solid line in Figures 1, 3 and 4, and one of several reclined positions as indicated in broken line in Figures 1 and 4. Thecomponents of theback rest assembly on opposite sides ofthe-chair are substantially identical-and accordingly only one side of the assembly is particularly described; like reference characters indicating like or corresponding right and left parts in the drawings.

Each side of the'reclinable back rest assembly has a rigid preferably tubular L-shaped back member comprising an upwardly extending long leg 24 and a short rearwardly" extending leg 25 secured to the lower end of a long leg. and extending rearwardly therefrom in the vertical plane of the long leg and of the adjacent side frame of the chair. A hand bar or handle 26 extends rearwardly from the upper end of eachlong leg 24, and a back rest panel 27, which may be a flexible fabric material for the folding chair shown, is secured to the front side of each long leg and extends transversely of the rear end of the chair for supporting the back of the occupant. Reinforcement and alignment of the upper ends of the back members is provided by a transverseba'r 28 which,'when the chair is unfolded for use greases as shown, is firmly connected to each of the right and left handles 26, Figure 2. To permit folding the chair and the back rest, the bar 28 preferably has a pivotal connection with the left handle 26 about which it may swing down to parallelism with the adjacent leg 24 when the right end 29 of the bar is disconnected from the right handle 26; the rearward part of the handle 26 removably screwing into the forward part and detachably securing the end 29 of the bar therebetween. The long legs 24of both back members are constrained by the bar 28 to lie in a common transverse plane perpendicular to the longitudinal planes of the chair side frames, and the back members are pivotally supported as at 32-34 at their lower rear ends behind the rear frame members 13 so as to swing together to selected angles of recline by mechanism described below.

Support for the lower end of each back member is provided by a base bar 30 and inclined strut 31, preferably tubular in form, secured as by brazing to the rear of the upright frame member 13 at or slightly below the level of the seat bars 15 and extending rearwardly from member 13. Base bar 30 is reinforced by a diagonal strut 31 extending between the rearward end of the bar and the lower part of frame member 13. The back member is mounted above the base bar 30 with long leg 24 directly behind and adjacent to rear frame member 13 and with short leg 25 lying directly above the base bar 30. Short leg 25 is pivotally connected to the rearward end of the base bar for pivoting about a fixed horizontal transverse axis 32 by means of an inverted LJ-bracket 33 secured to and depending from the short leg and connected to the base bar by a pin 34. Each

back member

24, 25, 26, therefore, pivots in the vertical plane of the chair side frame about the fixed pivot axis 32. When the back rest assembly 20 is in the up position shown in solid line in Figures 1 and 4, long leg 24 of the back member is behind and preferably slightly inclined from the rear of frame member 13, and the lower open end 24' of the leg 24 is then elevated slightly above the top of base bar 30. As each back member pivots rearwardly about axis 32, that is, in a counterclockwise direction as viewed in the drawings, the lower end of each leg 24 moves up and rearwardly from its position proximate to the base bar 30, see Figure 4, and the end 24' of the leg moves in an are having a center on the pivot axis 32.

In order to control forward and rearward pivoting of the back member and thereby adjustably to position it in selected angles of recline, an elongated preferably rigid link 35 having a narrow lower part 35a and a Wide upper part 3512 is disposed within each long leg 24 and is pivotally connected at its lower end to the forward end of base bar Bit by a pin to a fixed pivot support 36 for pivoting about a transverse horizontal axis 37. Support 36 is secured to the top of base bar 30, by suitable means such as brazing, directly under the lower open end of leg 24 when the latter is in the up position as shown in Figure 4. It has been noted that long leg 24 of the back member, when pivoted about rear pivot 32 from an up to a recline" position, moves upwardly from the base bar because pivot 32 is offset rearwardly from leg 24. However, since link 35 is pivotally anchored to the base bar and does not have translatory movement relative to the base bar, there will be axial movement of long leg 24 relative to link 35 when the leg and link pivot simultaneously about their respective pivot axes. In accordance with my invention, this relative movement between link 35 and leg 24 is utilized to provide selecti e adjustment and locking of the back rest assembly in one of several angles of recline.

Leg 24 moves not only up from but also rearwardly of support 36 on the base bar 3%] during rearward pivot- 'ing of the back member, and to prevent interference between leg 24 and lower link part 35a, the cross-sectioual dimensions of lower link part 35a preferably are substantially smaller than the inside diameter of the leg. Alternatively,

members

24 and 25 may be slotted to accommodate greater reclining movement of the back rest beyond, for example, the position shown in Figure 4. The width W, see Figure 5, of upper link part 35b preferably is slightly less than the inside diameter of long leg 24 to provide a small clearance between these parts in the direction of the link width, Figures 5 and 6, so that relative axial movement between the link and leg can take place without undue transverse play. The upper and lower link parts preferably are separate pieces pivotally connected together by transverse pin 40, see Figure 6, and is but slightly less in length L than the inside diameter of leg 24 whereby to be retained in operative relation to the link parts.

In order to lock long leg 24 and link 35 releasably together and prevent relative longitudinal movement between the leg and link 35 and thus to prevent pivotal movement of the back member either forwardly or rearwardly, upper link part 35b is formed with a longitudinal row of closely spaced transverse locking apertures 42. A locking pin 44, see Figure 5, disposed with its axis parallel to the axis of apertures 42, is mounted in a cylindrical housing 45 on the outer side of each leg 24, preferably on a level with the arm rest bar 16 on the forward part of the chair, and extends through an opening 46 in the wall of the leg for engagement in one of the link apertures 42. Pin 44 normally is urged into engagement with the link apertures by compression spring 47 in housing 45. A knob 48 on the outer end of each pin facilitates retraction of the pins in each leg for unlocking the links in each leg when it is desired to adjust the recline angle of the back rest assembly.

When the back rest assembly is in the up position, locking pin 44 engages a lower aperture 42', see Figure 4, in upper link part 35b. When it is desired to recline the back rest, each pin 44 is withdrawn from engagement with aperture 42', the back rest assembly is pivoted about fixed pivot axis 32, and long leg 24 of each back member moves longitudinally relative to link 35. It will be noted that locking pin 44 is radially spaced from the fixed pivotal axis 32 of the back member by a distance R and moves through an are having this radius during the backward pivoting of back member. Link 35 simultaneously pivots about its lower end to an angle corresponding substantially to the recline angle of the long leg, the lower locking aperture 42 moving about link pivot axis 37 through an are having a radius r. The angle of recline to which the back rest assembly is adjustable is determined, inter alia, by the number and spacing of locking apertures 42 in the link; the arc of movement of locking pin 44 intersecting the axis of upper aperture 42" at the maximum (shown) angle of recline of the back members, as shown in Figure 4. The locking pin 44 is transversely aligned with and thus is engageable in the upper aperture to positively lock the entire back rest assembly in the maximum recline position. The intermediate apertures in the link permit similar adjustment of the back rest assembly to intermediate angles of recline.

The spring loaded lock pins 44 on both legs 24 of the back members must be disengaged from the links 35 in order to release the back rest assembly for pivoting about the lower fixed axes 32. Since the operator must consciously pull the locking pins outwardly against the force of the compression springs 47 to release the links, the danger of inadvertently tripping the lock is eliminated and safety of the occupant is assured. It is possible for the back rest assembly to pivot beyond the maximum normal angle of recline determined by engagement of lock pin 44 in upper link aperture 42". Since the back member pivot axes 32 are rearwardly offset from the link pivot axes 37, continued rearward pivoting of the back members beyond the position shown in broken line in Figure 4 would tend to cause wedging of the lower link i greases parts 35a in legs 24 and mightresult in undue stressing of these parts, if the same were not slotted to accommodate it. To prevent this, any suitable permanent stop means for positively limiting relative movement of long legs 24 with respect to the links 35 substantially beyond the'normal limit of recline is provided. Forexample, one ofthe screws, indicated at 51 in Figures 3 and 4, which fastens the backrest panel-to each long leg 24 and which is located slightly below the enlarged upper link part 35b when the back members are at the maximum recline position, extends into each leg 24 sufiiciently to underlie the lower edge of theupperlink part and thus is adapted to engage and prevent furtherrelative movement betweenthe leg and link;

The entire reclinable backrest assembly 20' is operatively independent of the forward part "of the chair and therefore can-be attached to andfunction efiiciently on a. variety of types of chairs without substantial modification of the basic chair structure; For example, in a nonreclinable wheel chair of: the generaltype illustrated and described herein, that is, a wheel chair that does not have a reclinable; back restassembly 20, base bars 30 and associated reinforcing struts 31, the upper parts of the rear upright frame members 30 normally would extend substantially above the arm rest bars 16 and would carry the back rest panel and the rear handles. To modify such a chair to include the reclinable back rest assembly herein described, the portions of the members 13 above the arm rests 16 are removed, the back rest panel on members 13 omitted, and base bar 30, strut 31 and the assembly 20 added to the rear of these frame members. No other modification of the basic chair structure is required to convert it into one having a reclinable back feature.

In practice, I have found that a maximum angle of recline of the back rest of approximately 35 measured with respect to the vertical plane, is satisfactory. The magnitude of this maximum angle of recline is determined by the length of offset of the rear pivot axis 32 from long leg 24, the axial spacing between upper and lower link apertures 42, the inside diameter or slotting of leg 24, the longitudinal position of locking pin 44 on the long leg, and the height of the link pivot axis 37 above base bar 30. By way of example, a reclinable back rest assembly constructed according to my invention and having the following dimensions is desirably adjustable between minimum and maximum recline angles of (up position) and 35 wherein the rear pivot axis 32 is offset 3" rearwardly from the longitudinal axis of the long leg 24, inside diameter of leg 24 is link pivot axis 37 is spaced above the top of the base bar 30, the radius r of the arc of movement of the lower link aperture is 9 center to center spacing between the lower and upper link apertures is approximately 1%, and the radius R of the arc of movement of the locking pin is approximately 10%". It is apparent that with desired modification of the linkage described, the back rest assembly may be made to move to an up position perpendicular to the plane of the seat and to greater angles of maximum recline, if such is desired.

It is intended that the patent shall cover by suitable expression in the appended claims whatever features of patentable novelty reside in the invention.

I claim:

1. In a chair having a seat and a pair of laterally spaced rear upright frame members supporting said seat, the improvement of an adjustably reclinable back rest assembly supported on said rear frame members, comprising base bars secured to and extending rearwardly from said frame members, respectively, at substantially the level of said seat, a pair of back members on said base members, respectively, a transverse panel interconnecting said back members and forming the chair back rest, each of said back members comprising a long vertical tubular leg and a short horizontal leg rigidly connected to the rear lower portion of-tlie vertical leg; area'r transverse pivot for piv otally connecting-said"shortl'leg to said base bar adjacent the outer rear end of-said base bar, an elongated link extending withinthelower end of'said vertical leg-of the back member, saidlirile being pivotally connected to said base bar forwardly of said-rear pivot, the axes of said pivots being parallel, said long leg being'axially movable relative to-said link as said back member and said link are pivoted about their respective pivots andin a vertical plane, said-link having a plurality of transverse axially spaced apertures remote" froni the pivotal connection thereof-to said base'bar and locking pin means mounted on anchextending transversely of and intosaid longleg adjacent said linlc apertures and selectively engageable within one of said apertures for locking said back member at'a predetermined angle of recline -relative to said basebar;

2; In a chair having a" pair of laterally spaced rear upright'fram'e members; the improvement of an adjustably reclinable back restass'embly supported on said rear framemernbers; comprising a base bar secured to and extending:rearwardly from 'e'a'chuof said frame members, a ba'clz member'associated with each rear frame-member and having a rearwardlyextending short leg and an upwardly extending long tubular leg connected to the front end of the short leg, rear pivot means for pivotally connecting the rear end of said short leg to the rear end of said base bar, an elongated link disposed within and extending upwardly from the lower end of said long leg, said link being pivotally connected to said base bar forwardly of said rear pivot means and adjacent said rear frame member, said long leg being axially movable relative to said link as said back member and link are simultaneously pivoted in a vertical plane, and locking means carried on and extending into said long leg and releasably engageable with said link for locking said back rest member at a predetermined angle of recline relative to said base bar.

3. An adjustably reclinable back rest for a chair having a frame, said back rest comprising a back member mounted on the rear of the chair frame, said back member having an upwardly extending open ended leg, means for pivotally supporting the lower end of said leg on said chair frame at a point rearwardly offset from said leg, a link extending into the lower end of said leg and pivotally connected at its lower end to said frame adjacent the lower end of said leg, said leg moving axially relative to said link as said leg and said link are pivoted relative to said chair frame, and means releasably interconnecting said leg and said link for preventing pivoting of said leg relative to said chair frame.

4. An adjustably reclinable back rest for a chair having a frame, said back rest being mounted on the rear of the chair frame comprising an upwardly extending leg open at its lower end, means for supporting the lower end of said leg on said chair frame for pivotal movement about an axis offset from said leg, a link extending into the lower end of said leg and being supported on said frame for pivoting about an axis lying in the arc of movement of the lower end of said leg, said leg being longitudinally movable relative to said link during pivotal movement of said leg and said link relative to said frame, and locking means selectively releasably interconnecting said link and said leg to prevent said relative longitudinal movement therebetween and thereby to lock said leg at a predetermined angular position relative to said frame.

5. A reclinable chair back rest assembly comprising a tubular member, a support base, means for pivotally connecting one end of said member on said base offset from said member whereby said member pivots in a single plane, a rigid link member disopsed within said member, means for pivotally connecting one end of said link member to said base at a point in said plane proximate to the arc of movement of said one of said tubular member, and releasable locking means interconavaasre 7 necting said members for preventing longitudinal movement of one member relative to the other.

6. In an adjustably reclinable assembly of the type described, a rigid tubular member, a link member telescoped within said tubular member, a support base, means for pivotally connecting said members, respectively, to said base, the pivotal connection of one of said members being offset from the pivotal connection of the other member whereby relative longitudinal movement between said members occurs during simultaneous pivoting of said members about their respective pivots, and lock means for releasably interconnecting said members to prevent said longitudinal movement therebetween and thereby to prevent pivoting of said members relative to said base.

I. In a chair having a rear upright frame member, a seat supported on said member, and an arm rest bar spaced up from said seat and connected to the upper end of said frame member, an adjustably reclinable back rest assembly for said chair comprising a rigid tubular member juxtaposed to the rear of said frame member and extending upwardly from about the level of said seat to substantially above the level of said arm rest bar, a back rest panel supported on said tubular memher, a base bar rigidly secured to and projecting rearwardly from said frame member at about the level of said seat, means for pivotally connecting said tubular member to said base bar for pivoting in the plane of said frame member,.a link disposed within said tubular member, means for pivotally connecting said link to said base bar for pivoting in said plane, the pivotal connection of said link being closer to said frame member than the pivotal connection of said tubular member whereby said tubular member moves longitudinally relative to said link when both are pivoted simultaneously relative to the base bar, said link having a plurality of transverse apertures arranged in a longitudinal row, a transverse pin longitudinally fixed on said tubular member proximate to said link apertures and selectively engageable in one of said apertures for preventing longitudinal movement of said tubular member relative to said link.

Conboy July 23, 1912 Wittwer Feb. 19, 1918