US3788701A

US3788701A - Chair construction

Info

Publication number: US3788701A
Application number: US00257249A
Authority: US
Inventors: R Massaccesi
Original assignee: All Steel Inc
Current assignee: All Steel Equipment Inc
Priority date: 1972-05-26
Filing date: 1972-05-26
Publication date: 1974-01-29
Anticipated expiration: 1991-01-29
Also published as: CA975282A

Abstract

A chair construction comprising a frame in the form of a pair of L-shaped rigid frame members, defining the frame back and seat reinforcing portions secured together in side by side spaced apart relation by a pair of cross members applied between the frame member seat portions, contoured seat and back upholstery plates each having a separate cushion pad applied thereto, with the plates being made fast to the frame and between said frame members to form a seat subassembly, and with the plates having their side edges aligned about the rim of the subassembly, and a one piece shell of concavo-convex, L-shaped configuration having a continuous rim thereabout substantially complementing that of the subassembly, with the subassembly received in the shell and the shell secured to the subassembly at an indentation formed in the underseat portion of the shell, and about the rims of the shell and subassembly. A molding about the rim of the shell masks the fastening elements about the shell rim and forms a bumper for the chair, and a conventional chair base is affixed to the frame at the shell indentation.

Description

United States Patent [191 Massaccesi CHAIR CONSTRUCTION [75] Inventor: Raymond A. Massaccesi, Lombard,

[73] Assignee: All-Steel Inc., Aurora, 111.

[22] Filed: May 26, 1972 [21] Appl. No.: 257,249

[52] US. Cl 297/455, 297/449, 297/451 [51] Int. Cl A47c 7/02, A47c 1/12 [58] Field of Search 297/454-455, 420-421,

[56] References Cited UNITED STATES PATENTS 2,642,126 6/1953 Grabendike 297/451 3,026,145 3/1962 Galbraith 297/458 UX 3,159,428 12/1964 Schier 297/455 X 3,182,377 5/1965 Hoven et al. 297/DIG. 2 3,223,450 12/1965 Pollock 297/454 X 3,298,743 1/1967 Albinson et a1 297/445 3,482,874 12/1969 Henebry et a]. 297/452 X 3,630,566 12/1971 Barecki 297/454 3,669,499 6/1972 Semplonius 297/455 3,476,342 11/1969 Motl et a1. 297/445 X 2,965,161 12/1960 Knoll 297/440 Jan. 29, 1974 Primary Examiner-Paul R. Gilliam Attorney, Agent, or Firm-Robert C. Brown, Jr. et al.

[5 7] ABSTRACT A chair construction comprising a frame in the form of a pair of L-shaped rigid frame members, defining the frame back and seat reinforcing portions secured together in side by side spaced apart relation by a pair of cross members applied between the frame member seat portions, contoured seat and back upholstery plates each having a separate cushion pad applied thereto, with the plates being made fast to the frame and between said frame members to form a seat subassembly, and with the plates having their side edges aligned about the rim of the subassembly, and a one piece shell of concave-convex, L-shaped configuration having a continuous rim thereabout substantially complementing that of the subassembly, with the subassembly received in the shell and the shell secured to the subassembly at an indentation formed in the underseat portion of the shell, and about the rims of the shell and subassembly, A molding about the rim of the shell masks the fastening elements about the shell rim and forms a bumper for the chair, and a conventional chair base is affixed to the frame at the shell indentation.

7 Claims, 9 Drawing Figures PATENTEDJAN 29 m4 SHEEI 1 [IF 3 F l|||l II ommgnm 2 9 m1 SHEET 3 [IF 3 CHAIR CONSTRUCTION This invention relates to a chair construction, and more particularly, to a chair construction for office use.

A number of existing chair constructions for office use involve the use of an outer plastic shell that defines the visible portion of the chair back and seat underportion and that is shaped to define continuous sweeping curves from the top to the front of the chair and give the impression of sitting into a comfortable wraparound bucket seat. Existing constructions of this type, while having some appeal to the trade because of the aesthetic effect involved, have proved to be overly expensive due to the manner in which the parts are secured together, and the fact that in a number of these arrangements, the outer shell forms a part of the load bearing structure of the chair.

A principal object of the present invention is to provide a chair construction employing a one piece L- shaped shell that defines the back and undersurface of the chair and gives the desired smoothly rounded shell contour, in which the shell has essentially no load carrying functions and is secured to an Lshaped seat subassembly defined by an L-shaped rigid frame that forms the chassis of the chair and has secured to it the chair cushioning and the chair supporting base, as well as the chair arms (where employed).

Another principal object of the invention is to provide a chair construction in which the load bearing structure of the chair is a separate subassembly of L- shaped form defining seat and back portions to which is attached a non-load bearing shell that provides the distinctive shell shape, and which is arranged at the underseat portion of same for ready securement to the chair frame, through the shell, of the chair base employed.

Other objects of the invention are to provide a chair construction utilizing a non-structural and primarily decorative shell that forms the back and bottom of the chair seat, in conjunction with a rigid load-bearing frame that carries the chair cushions which frame is connected to the chair base through restricted and isolated portions of the shell, to provide a method of making a chair construction of the type indicated, and to provide an office furniture oriented chair arrangement that is economical of manufacture, distinctive in appearance, and long lived in use.

In accordance with this invention, there is provided a chair arrangement employing a seat subassembly comprising an L-shaped frame, formed by a pair of L shaped members fixed together in side by side spaced apart relation, and mounting seat and back upholstery plates to which are applied separate seat cushions, with the side edges of the plates being aligned about the rim of the subassembly, which is received in a one piece concavo-convex shell of L-shaped configuration that has no substantial load bearing function, and has its underseat portion indented upwardly to mask the attachment of same, and the chair base, to the frame. The shell defines a rim that complements the rim of the seat subassembly, and the seat subassembly and shell rims are secured together by fastening screws that are masked by a molding or trim applied about the shell rim. The back of the frame subassembly is shaped with a reverse bend to complement the back side of the human anatomy when seated. Chair arms of open centered, quadrilateral configuration are secured (when employed) to the frame subassembly, and are shaped for complementary positioning adjacent the frame subassembly back and seat. Seat cushions are secured to the respective upholstery plates by a decorator fabric stretched against the same and having its edges stapled against the back side of the respective plates to hold them in place.

Other objects, uses and advantages will be obvious or become apparent from a consideration of the following detailed description and the application drawings.

In the drawings: 2

FIG. 1 is a diagrammatic perspective view of a chair arranged in accordance with this invention, with the chair arms shown in outline form;

FIG. 2 is a side elevational view of the load supporting frame that is employed in connection with the chair of FIG. 1, with parts broken away;

FIG. 3 is an elevational view of the frame shown in FIG. 2, taken from the left hand side of FIG. 2, with parts broken away;

FIGS. 4 and 5 are rear and bottom views, respectively, of the frames of FIGS. 2 and 3, shown having applied thereto the cushion bearing upholstery plates, to form the seat subassembly of the chair of FIG. 1;

FIG. 6 is a transverse cross-sectional view through the chair seat, taken substantially along line 6-6 of FIG. 1, indicating the manner in which the seat frame, the chair shell, and the chair base are secured together;

FIG. 7 is a side elevational view of the chair shown in FIG. 1, with parts broken away along line 77 of FIG. 6;

FIG. 8 is a diagrammatic sectional view through the back of the chair, taken substantially along lines 88 of FIG. 7; and

FIG. 9 is a typical cross-sectional view of the molding that is used in connection with the chair shell, on an enlarged scale to better bring out the details of the molding, with the shell rim to which it is applied being shown in outline.

However, it is to be understood that the specific drawing illustrations provided are supplied primarily to comply with the requirements of the Patent Laws, and that the invention may have other embodiments that will be obvious to those skilled in the art, and that are intended to be covered by the appended claims.

GENERAL DESCRIPTION Reference numeral 10 of FIG. 1 generally indicates a chair construction in accordance with the present invention comprising seat .structure 12 mounted on a suitable conventional chair base 14. Chair 10 is arranged specifically for use as an office furniture chair for use in conjuction with desks and the like.

The chair seat 12 generally comprises a rigid skeletal frame 16 (see FIGS. 2 5), comprising a pair of

rigid frame members

18 and 20 secured rigidly together in spaced apart side by side parallel relation by a pair of spaced

cross members

22 and 24.

Affixed to the frame 16 is a seat bottom plate 26 and a pair of

seat back plates

28 and 30 that are secured to and between

frame members

18 and 20 by suitable fastening devices, such as screws 32 in the case of plate 26, and screws 34 in the case of plates 28 and 30 (see FIGS. 4 and 5).

Plates

26, 28 and 30 are formed from a suitable plastic material, contoured substantially in the manner indicated in FIGS. 6, 7 and 8, and each upholstery plate has secured thereto its own cushion pad and covering therefor. In the case of the plate 26, it has cushion pad secured thereto by a covering fabric 42 of a suitable decorator type that is stretched tightly against the cushion from all sides and has its edges 44 fixed to the back side of the plate by suitable staples 46.

In the case of plate 28, pad 48 is secured thereagainst by fabric covering 50 of a suitable decorator type that is stretched tight against the pad 48 and has its edges 52 secured to the back of the plate 28 by suitable staples 54.

Similarly, upholstery plate 30 has pad 56 secured thereagainst by fabric covering 58 stretched tight against the pad 56 and having its edges 60 affixed to the back side of the plate by suitable staples 62.

The frame 16,

upholstery plates

26, 28 and 30, and the cushion pads they carry form the seat subassembly 64 that is shown in FIGS. 4 and 5 that, in accordance with this invention, is operably associated with shell 66 that is generally L-shaped, concave-convex, in configuration, and is proportioned to receive the subassembly 64, with the seating area of the chair facing outwardly of the shell 66.

As indicated in FIGS. 4 and 5, the

decorator plates

26, 28 and 30 are proportioned so that their side edges are aligned to define a rim portion 68 for the subassembly 64 that is received in substantial complementary relation with a corresponding rim portion 70 defined by shell 66. The

rim portions

68 and 70 of the seat subassembly 64 and shell 66 are secured together thereabout by suitable screws 72 that are masked by a molding 74 carried by the rim portion 70 of the shell 66.

As indicated in FIGS. 6 and 7, the shell 66 defines a smoothly contoured seat back portion 76 which merges into a smoothly contoured seat underportion 78, with the outwardly facing surface 80 of the shell being convexly rounded in configuration, except for indentation 82 that is formed in theseat underportion 78 to receive the upper end of the chair base for connection of same to frame 16. I

In accordance with the embodiment illustrated, the conventional upper end of the housing 84 that houses the usual base swiveling and/or tilting mechanism 85 is secured to the respective

frame cross members

22 and 24 by suitable bolts 86 applied through holes 88 formed in shell 66 and holes 89 formed in the

respective cross members

22 and 24 to weld nuts 91 carried thereby. This, of course, also secures the shell 66 to the frame 16, but in accordance with this invention, the only connections of the shell 66 to the-frame 16 are by way of the bolts 86 and the screws 72 that fix the shell rim portion 70 to the seat subassembly rim portion 68.

Where chair arms are desired, the invention contemplates

chair arms

88 and 90, which in accordance with this invention are to form a part of subassembly 64 by being secured to same prior to the application of subassembly 64 to the shell 66. For this purpose, the arms 88 and are respectively provided with a pair of spaced

apart attachment lugs

92 and 94, respectively, which are affixed to correspondingly located spaced apart

brackets

96 and 98 by employing suitable fastener devices 100.

However, where the chair 10 is to be armless,

arms

88 and 90 would be omitted, together with their

brackets

96 and 98.

As indicated in FIGS. 2 and 7, the seat subassembly 64 defines a seat back portion 102 which is generally contoured to conform to the back side of the human anatomy when seated, and for this purpose defines the reverse bend that is generally indicated by reference numeral 104 and that projects forwardly in the nature of an apex. The seat subassembly 64, of course, further defines the chair seat portion 106 that the chair user sits on.

SPECIFIC DESCRIPTION The components making up frame 16 are formed from a suitable metallic substance, such as steel. The

frame members

18 and 20 in the form shown are tubular in nature and are quadrilateral in cross-sectional configuration (square in the form shown). As indicated in FIGS. 2,

members

18 and 20 each define a chair back portion 110 and a chair seat portion 112, with the

portions

110 and 112 merging together in a smoothly rounded curved portion 114. The back portion 110 is not straight throughout its length, but in the form shown includes

rectilinear segments

116 and 118 that merge together at curve portion 120 to define the reverse bend or curve 104.

Members

18 and 20 are formed with suitable holes 122 to accommodate screws 34.

Cross members

22 and 24 are of the hat style channel-shaped cross-sectional configuration indicated in FIG. 7 and each thus defines spaced side walls and 132 joined together by web 134 and having laterally extending flanges or wings 136 projecting outwardly of the

walls

130 and 132.

The

members

22 and 24 are curvilinear transversely of the chair (see FIG. 6) and are suitably affixed to the

frame members

18 and 20, as by welding. In the form shown, the

walls

130 and 132 of the

respective members

22 and 24 are recessed to receive the portions 112 of the

respective members

18 and 20, with the wall 134 and flanges or wings 136 being applied thereto in overlapping relation, and the parts suitably welded together. Weld nuts 91 are affixed to webs 134 of the

respective members

22 and 24 adjacent holes 89 and each includes a tapped opening 137 to which the respective screws 86 are applied.

Where the chair is to have

arms

88 and 90, the frame 16 includes the

brackets

96 and 98, each of which comprises a member 140 of channel-shaped cross-sectional configuration formed from steel or the like and'defining web 142, side flanges 144 and 146- and a tab 147 projecting from end 148 of member 140. The end 148 of the member 140 and its tab 147 are fixed as, by welding, to the

respective members

18 and 20 in the positions indicated in FIGS. 2 and 3 for each member 140, wherein members 140 are upwardly inclined, with their ends 149 projecting away from frame 16, to accommodate the contour of the shell 66 and have applied thereto the

respective lugs

92 and 94 of the re

spective handles

88 and 90. Members 140 are formed with suitable openings 149 to receive screws 150 that secure the respective handle lugs to the respective members 140.

The

upholstery plates

26, 28 and 30 are preferably formed from a suitable plastic material, such as styrene. Where formed by a molding operation, the

screws

32 and 34 will be of the self tapping type, but if the

plates

26, 28 and 30 are vacuum formed, a nut may be embedded in the plastic plates at each location of the

screws

32 and 34, in which case the latter may be stan- 'dard screws. Plate 26 and

frame members

22 and 24 are arced in a complementary manner (see FIG. 6) and

plates

28 and 30 arced as suggested in FIG. 8, for conformity with body contour.

The

plates

26, 28 and 30 at their edges that form a part of the rim portion 68 of seat assembly are shaped to define an angled flange 160 to which the screws 72, which may be of the self tapping type, are applied to secure the shell 66 to the respective plates.

Thus, the flange I60 appears along the front edge 162 and side edges 164 of bottom plate 26, the side edges 166 of back plate 28, and the side edges 168 and top edge 170 of back plate 30, with the flange 160 being angled appropriately in each instance for ready application of the securing screws 72 (see FIGS. 6, 7 and 8).

As indicated in FIGS. 5 and 6, the screws 32 that secure bottom plate 26 in place are applied to adjacent flanges 136 of the

respective cross members

22 and 24, and adjacent the ends of these members.

The cushion pads 40, 48 and 60 may be formed from any suitable cushioning material, such as a neoprene or soft plastic foam. The

cover fabrics

42, 50 and 58 may be of any suitable decorator fabric or the like that will serve the purpose. Tufting may be employed as desired, with this being effected before application of the upholstery plates to the frame 16.

While

upholstery plates

28 and 30 are separate in the form illustrated, they may be secured together along their adjacent edges, as by application to a steel strip with screws, and then be upholstered as one cushion to define the general outline indicated in the drawing without the joint that appears at reverse bend 104.

The

chair arms

88 and 90 are preferably formed from a suitable phenolic, ac'rylonitrile butadiene styrene (ABS) material, though they alternately may be die cast aluminum. Each arm is a one piece component having a body portion 180 (see FIG. 7) of generally quadrilateral, open centered, trapezoidal configuration. The body 180 of each arm defines

rectilinear portions

182, 184, 186 and 188, which the rectilinear portion 188 of each arm being in substantial parallelism with the portion 116 of

frame members

18 and 20, while the arm portion 186 is in substantial parallelism with the portions of the seat assembly and shell rims that underline same (see FIG. 7). The jucture of the seat bottom and back portions, the shell and seat assembly rims, and thus the molding 74, defines circular curve configuration 190, and the curved corner 192 of the respective handle bodies 180 is in complementary relation thereto. The other

curved corners

194, 196 and 198 join the handle portions indicated with the curved configurations indicated.

In the form shown, the handle lugs 92 and 94 have nut inserts 200 embedded therein with which the respective securing screws 150 cooperate to secure the respective lugs to the respective bracket members 140. Inserts 200 in the form shown comprise threaded sleeves 201 ultrasonically welded in place. Screws 150 and inserts 200 form the respective fastener devices 100, with handle lugs 92 and 94 being applied to the upper sides of webs 142 in the form shown.

The shell 66 is formed from a suitable plastic material, such as polypropylene, molded to the shape indicated. The shell 66 is primarily decorative in function, and servers no load supporting functions except in compression in the limited areas of screw holes 88. As indicated in FIGS. 6 and 7, the rim portion 70 of the shell 66 is formed to define angled edge 210 that is continuous thereabout, and which is covered by the molding 74.

The molding 74 is formed from a suitable vinyl material or the like such as polyvinyl chloride, and has the Ushaped cross-sectional configuration shown in FIG. 9 to define a side portion 212 that engages the inner surface 214 of the shell, and an outer side 216 that is to be applied over the outer surface 218 of the shell to mask the fastening screws 72. The side 216 is recessed as at 220 to complement the angled edge 210 of the shell, and is further recessed aa at 222 to receive the heads of the respective screws 72, it being understood that the

recesses

220 and 222 are continuous along the length of the molding 74. Molding 74 is applied to the shell in strip form prior to application thereto of the seat subassembly 64, and after the seat subassembly 64 has been positioned in the shell 66 and screws 86 applied thereto, the assembler moves about the rim portion of shell 66, lifting the molding sides 216 in overlying relation to the applied screw 72 to fully mask same. Screws 72 are applied through molding side 212.

Molding 74 additionally serves as a bumper for the chair to protect the shell 16. The molding is so formed that the

side portions

212 and 216 engage each other at their edges 224 and 226 after extrusion so as to resiliently grip the shell rim portion 70.

Chair base 14 may be of any conventional type, that shown including the usual supporting legs 230 mounting casters 232 and applied to pedestal 234 in any conventional manner.

It will therefore be seen that the invention provides a chair arrangement in the form of a load supporting framework that defines the basic seat contour of the chair and has affixed thereto the chair cushion padding and arms (where arms are employed), which is applied to an outer, essentially load free shell that masks the chair frame from the rear of the chair and provides the desired rounded wrap around bucket seat type look. The shell at its underseat portion also partially masks the upper portion of the chair base by the upwardly directed indentation formed in same which also serves to locate the chair base for securement to the chair frame through the material forming the shell.

The arrangement of the upholstery plates in permitting the cushion covering fabric to be stapled to the back sides of same to hold the padding in place provides significant simplification of assembly procedures.

The manner of applying the

chair arms

88 and 90, whereby they are secured to seat portion of the chair only, adapts the chair construction of this invention for utilizing an articulating posture" back structure for executive models of the chair.

The foregoing description and the drawings are given merely to explain and illustrate the invention and the invention is not to be limited thereto, except insofar as the appended claims are so limited, since those skilled in the art who have the disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention.

I claim:

1. In a shell chair including a chair base, a load bearing frame supported by the chair base and having seat and back cushion means secured thereto, and a load free shell of generally L'shaped concavo-convex configuration secured to said base and underlying said frame and defining a marginal rim thereabout, the improvement wherein:

said frame comprises a pair of generally L-shaped rigid frame members secured together in upright spaced apart substantially parallel relation to define a skeletal framework, with each of said frame members being shaped to define chair seat and back portions,

said frame members being secured together at said seat portions thereof by a pair of spaced apart cross members in substantial parallelism and in fixed relation to said frame members,

contoured seat and back upholstering plates made fast to and between said frame members in covering relation thereto and defining upwardly and forwardly facing load support surfaces, respectively,

said upholstering plates each having cushion means secured over said surfaces thereof in masking relation thereto,

said framework, said plates and said cushion means forming a subassembly of generally L-shaped configuration defining chair seat and back portions of which said cushion means defines the seating area of said chair,

said subassembly being received within said shell with the seating area of said chair facing outwardly of said shell,

said shell defining a chair seat under portion and a chair back portion, and the seat and back portions of said frame subassembly being received in said shell seat under portion and back portion respectively,

said shell and upholstering plates defining substantially complementing edge portions in substantial juxtaposition about the rim of said shell whereby said skeletal frame is enclosed between and masked by said shell and said cushion means,

meansfor anchoring said upholstery plates to said shell at spaced points about said edge portions,

said chair base being secured to said subassembly framework at said seat portion thereof,

with said shell seat under portion being interposed between said chair base and said subassembly seat portion,

and a molding overlying said shell edge portion and masking said anchoring means, said subassembly back portion being shaped to define along the back portion of the chair seating area a lower forwardly angled portion merging into an upper rearwardly angled portion to define a reverse bend in said subassembly back portion seating area in general conformity with the back side of the human anatomy in the sitting position, and having a forwardly projecting apex,

said upholstering plates of said subassembly back portion comprising a pair of said plates, with one plate of said pair being located at said lower subassembly back portion and the other of said plates being located at said upper subassembly portion,

with said cushion means of said pair of plates being in juxtaposition at said reverse bend and defining a joint forming indentation lying along said apex thereof.

2. The improvement set forth in claim 1 wherein:

said base is secured to said framework by fastener means making said base fast to said framework cross members,

said fastener means also making said shell seat under portion fast to said cross members.

3. The improvement set forth in claim 1 including:

a chair arm at each side of and secured to said subassembly seat portion,

said arms each being of open centered generally quadrilateral and planar configuration and each defining a pair of lugs extending downwardly thereof that are spaced apart in the plane of the respective arms,

and means for anchoring the respective arm lugs to the seat portions of the respective subassembly frame members and beneath said cushion means of said subassembly seat portion to mount the respective arms at each side of said subassembly.

4. The improvement set forth in claim 1 wherein:

said seat upholstering plate is concavely curved on its upwardly facing side and correspondingly convexly curved on its downwardly facing side, crosswise of the chair,

said frame cross members having a curvature complementing that of said seat plate and said seat plate resting on said cross members and being made fast thereto.

5. The improvement set forth in claim 1 wherein:

said upholstery plates are formed from a plastic material,

said cushion means for each of said plates comprising:

a pad of resilient material proportioned to cover the plate to which it is secured,

and a sheet of decorator fabric received over and bearing against the pad with the edges of the sheet anchored to the underside of the plate.

6. The improvement set forth in claim 1 wherein:

said molding comprises:

a stripping of resiliently flexible material of generally U-shaped cross-sectional configuration defining opposed molding sides,

said shell edge portion defining an outwardly angled rim portion thereabout,

said molding being received over said shell rim portion with the molding sides engaging the respective sides of said shell about the rim of said shell,

with the side of said molding engaging the convex side of said shell being formed to receive said shell edge portion and accommodate said anchoring means,

said molding serving as a bumper for said chair.

7. The improvement set forth in claim 3 wherein:

said means for anchoring the respective arm lugs to the respective frame members comprises:

a pair of channel elements secured to each of said frame members and projecting sidewise of the chair and spaced to receive the respective arm lugs,

and screw means for securing the respective arm lugs to the respective channel elements.

Claims

1. In a shell chair including a chair base, a load bearing frame supported by the chair base and having seat and back cushion means secured thereto, and a load free shell of generally Lshaped concavo-convex configuration secured to said base and underlying said frame and defining a marginal rim thereabout, the improvement wherein: said frame comprises a pair of generally L-shaped rigid frame members secured together in upright spaced apart substantially parallel relation to define a skeletal framework, with each of said frame members being shaped to define chair seat and back portions, said frame members being secured together at said seat portions thereof by a pair of spaced apart cross members in substantial parallelism and in fixed relation to said frame members, contoured seat and back upholstering plates made fast to and between said frame members in covering relation thereto and defining upwardly and forwardly facing load support surfaces, respectively, said upholstering plates each having cushion means secured over said surfaces thereof in masking relation thereto, said framework, said plates and said cushion means forming a subassembly of generally L-shaped configuration defining chair seat and back portions of which said cushion means defines the seating area of said chair, said subassembly being received within said shell with the seating area of said chair facing outwardly of said shell, said shell defining a chair seat under portion and a chair back portion, and the seat and back portions of said frame subassembly being received in said shell seat under portion and back portion respectively, said shell and upholstering plates defining substantially complementing edge portions in substantial juxtaposition about the rim of said shell whereby said skeletal frame is enclosed between and masked by said shell and said cushion means, means for anchoring said upholstery plates to said shell at spaced points about said edge portions, said chair base being secured to said subassembly framework at said seat portion thereof, with said shell seat under portion being interposed between said chair base and said subassembly seat portion, and a molding overlying said shell edge portion and masking said anchoring means, said subassembly back portion being shaped to define along the back portion of the chair seating area a lower forwardly angled portion merging into an upper rearwardly angled portion to define a reverse bend in said subassembly back portion seating area in general conformity with the back side of the human anatomy in the sitting position, and having a forwardly projecting apex, said upholstering plates of said subassembly back portion comprising a pair of said plates, with one plate of said pair being located at said lower subassembly back portion and the other of said plates being located at said upper subassembly portion, with said cushion means of said pair of plates being in juxtaposition at said reverse bend and defining a joint forming indentation lying along said apex thereof.

2. The improvement set forth in claim 1 wherein: said base is secured to said framework by fastener means making said base fast to said framework cross members, said fastener means also making said shell seat under portion fast to said cross members.

3. The improvement set forth in claim 1 including: a chair arm at each side of and secured to said subassembly seat portion, said arms each being of open centered generally quadrilateral and planar configuration and each defining a pair of lugs extending downwardly thereof that are spaced apart in the plane of the respective arms, and means for anchoring the respective arm lugs to the seat portions of the respective subassembly frame members and beneath said cushion means of said subassembly seat portion to mount the respective arms at each side of said subassembly.

4. The improvement set forth in claim 1 wherein: said seat upholstering plate is concavely curved on its upwardly facing side and correspondingly convexly curved on its downwardly facing side, crosswise of the chair, said frame cross members having a curvature complementing that of said seat plate and said seat plate resting on said cross members and being made fast thereto.

5. The improvement set forth in claim 1 wherein: said upholstery plates are formed from a plastic material, said cushion means for each of said plates comprising: a pad of resilient material proportioned to cover the plate to which it is secured, and a sheet of decorator fabric received over and bearing against the pad with the edges of the sheet anchored to the underside of the plate.

6. The improvement set forth in claim 1 wherein: said molding comprises: a stripping of resiliently flexible material of generally U-shaped cross-sectional configuration defining opposed molding sides, said shell edge portion defining an outwardly angled rim portion thereabout, said molding being received over said shell rim portion with the molding sides engaging the respective sides of said shell about the rim of said shell, with the side of said molding engaging the convex side of said shell being formed to receive said shell edge portion and accommodate said anchoring means, said molding serving as a bumper for said chair.

7. The improvement set forth in claim 3 wherein: said means for anchoring the respective arm lugs to the respective frame members comprises: a pair of channel elements secured to each of said frame members and projecting sidewise of the chair and spaced to receive the respective arm lugs, and screw means for securing the respective arm lugs to the respective channel elements.