Lightweight plastic furniture

A lightweight, high-strength support platform for use in furniture construction, which has superior structural integrity and can be used, by way of example, in portable folding tables, in work tables and in modular furniture of the character typically used in modern office complexes. The support platform embodies a novel structural reinforcement core, and exhibits superior strength characteristics. In one form of the invention, the support platform is used in the construction of a lightweight, readily portable folding table which includes two pair of legs that are pivotally connected to the platform for pivotal movement between an extended operational position and a retracted storage and transport position.

BACKGROUND OF THE INVENTION 
Field of the Invention 
The present invention relates generally to plastic furniture. More 
particularly, the invention concerns a lightweight plastic folding table 
having a novel, structurally reinforced support platform providing a work 
surface. 
DISCUSSION OF THE INVENTION 
Lightweight furniture which exhibits superior structural characteristics is 
in wide demand for many industrial and institutional applications. 
Entities having great need for such furniture include schools, convention 
centers, hotels, factories, business offices and various governmental 
entities. Particularly in demand are lightweight folding tables and 
lightweight modular units for use in offices and the like which are 
readily portable and easily storable when not in use. 
While many types of lightweight furniture have been suggested in the past, 
a typical drawback of such furniture is a lack of structural integrity 
which tends to contribute to limited useful life and to frequent 
structural failures. As a general rule, when the prior art furniture 
designers have attempted to correct the structural deficiencies in the 
prior art designs, the furniture becomes excessively heavy and unduly 
bulky. As will be discussed in greater detail in the paragraphs that 
follow, the thrust of the present invention is to provide lightweight, 
readily portable furniture which embodies a unique structural 
reinforcement core that provide superior structural integrity to the 
furniture without unduly increasing its weight or bulkiness. 
Exemplary of typical prior art plastic folding tables are those described 
in U.S. Pat. No. 4,951,576 issued to Cobos et al. The Cobos et al tables 
include upper and lower plastic table top halves and a framework grid, 
preferably made of wood, sandwiched therebetween. Another example of a 
prior art folding table is that described in U.S. Pat. No. 5,394,808 
issued to Dutro et al. This table has a unitary table top formed of molded 
plastic preferably having an outer shell of non-cellular plastic with a 
filling of lightweight hardened foam. Other examples of prior art table 
constructions can be found in U.S. Pat. No. 5,271,338 issued to Bonham and 
in U.S. Pat. No. 3,628,470 issued to DeLucas. French Patent No. 1371706 
issued to Evans shows a reinforcement member having a multiplicity of 
upstanding protuberances. However, the balance of the Evans structure is 
totally dissimilar to that of the present invention. 
Because of the general similarities between the table of the present 
application and the table described in U.S. Ser. No. 08/592,458, of which 
this application is a Continuation-In-Part, application Ser. No. 
08/592,458 filed by one of the present inventors on Jan. 26, 1996 is 
hereby incorporated by reference as though fully set forth herein. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a lightweight, 
high-strength support platform for use in furniture construction, which 
has superior structural integrity and can be used, by way of example, in 
portable folding tables, in work tables and in modular furniture of the 
character typically used in modern office complexes. 
More particularly, it is an object of the invention to provide a 
lightweight support platform of the aforementioned character which 
embodies a novel structural reinforcement core which is both lightweight 
and exhibits superior strength and durability characteristics. 
Another object of the invention is to provide a lightweight, readily 
portable folding table which embodies a lightweight plastic support 
platform of the character described in the preceding paragraphs and which 
the table includes structural reinforcement beams (which are generally "C" 
shaped in cross section) and further includes pivotally mounted legs that 
can be pivoted from an extended operational position into a retracted 
storage and transport position wherein they abut the reinforcement core of 
the support platform. 
Another object of the invention is to provide a lightweight folding table 
which includes a uniquely configured top, the margins of which are 
reinforced by a novel structural reinforcement frame. 
Another object of the invention is to provide a lightweight folding table 
of the aforementioned character which is unusually strong, is highly 
reliable in use and has a long useful life. 
Another object of the invention is to provide a lightweight, high-strength 
foldable table of the character described which is constructed from 
readily available moldable plastic materials and one which can be 
efficiently and inexpensively manufactured in high volume. 
Still another object of the invention is to provide a light weight folding 
table of the class described in the preceding paragraphs which is highly 
attractive and easy to operate.

DESCRIPTION OF THE INVENTION 
Referring to the drawings and particularly to FIGS. 1, 2A and 2B, one 
embodiment of the lightweight, high strength folding table of the present 
invention is there illustrated and generally designated by the numeral 11. 
The folding table of this form of the invention is similar in many 
respects to the folding tables shown in incorporated by reference Ser. No. 
08/592,458 and comprises a support platform assembly 12 and first and 
second leg assemblies 14 and 15, each of which comprises a pair of 
downwardly extending legs designated in FIG. 1 as 18 and 20, which legs 
are pivotally connected to platform 12. 
An important feature of the present invention is the uniquely configured 
support platform 12 which is used in the construction of table 11. 
Referring particularly to FIGS. 2A and 2B, this novel support platform can 
be seen to comprise a support member or cover 22 which defines a work 
surface 22a and a structural reinforcement panel 24 (FIG. 2B) which is 
connected to support member 22 in a manner presently to be described. 
As best seen in FIGS. 2A and 3, support member 22 includes a generally 
planar first or work surface 22a as well as a second generally planar 
surface 22b which is spaced apart from surface 22a. Additionally, support 
member 22 includes a peripheral side wall 22c which circumscribes first 
surface 22a and defines a downwardly depending, skirt-like portion of the 
character best seen in FIG. 2A. Support member 22 can be constructed from 
a number of different types of moldable plastic materials such as 
polyethylene, styrene, polyproplylene and like materials. However, 
acrylonitrile butadiene styrene (ABS) is preferred. 
An important aspect of the support platform construction of the present 
invention is the uniquely configured, relatively thin plastic 
reinforcement panel 24. As illustrated in FIGS. 4 and 5 reinforcement 
panel 24 is interconnected with support member 22 and functions in a novel 
manner to provide substantial structural support to member 22 so that work 
surface 22a can withstand substantial vertical loading. Panel 24 can be of 
various configurations and can also be constructed from a number of 
moldable plastic materials of the character described in the preceding 
paragraph, but once again ABS is preferred. Depending upon the material 
selected, panel 24 can be vacuum formed, injection molded or molded in a 
number of other ways well known to those skilled in the art. 
Referring particularly to FIGS. 2A, 3 and 4, the novel reinforcement panel 
24 can be seen to include a central portion 28 and a peripheral portion 30 
which circumscribes central portion 28. The central portion is uniquely 
formed to provide a multiplicity of spaced-apart, specially configured 
upstanding protuberances 34. As shown in FIGS. 3 and 4, each protuberance 
34 comprises a base portion 34a, a vertically spaced-apart, generally 
circular-shaped closure wall 34b, and a tapered connecting wall 34c which 
interconnects base portion 34a and closure wall 34b. While protuberances 
34 are shown in the drawings as being generally frustoconical in shape, 
the protuberances can take on a wide variety of shapes. For example, top 
wall 34b of each protuberance, rather than being circular in shape, could 
be hexagonal or octagonal in shape should the designer so desire. As was 
the case in the table described in incorporated by reference application, 
Ser. No. 08/592,458 (FIG. 9), a multiplicity of web-like structures 
interconnect protuberances 34 so as to provide additional strength to the 
reinforcement panel. Additionally, a multiplicity of cavities 37 are 
provided intermediate protuberances 34. Cavities 37 are also generally 
frustoconical in shape and terminate in base closure walls 37a (see also 
FIG. 5). 
The peripheral portion of reinforcement panel or core 24 comprises a 
circumscribing flange-like portion 40 which defines generally planar upper 
and lower surfaces 40a and 40b. As best seen in FIGS. 3 and 8, flange-like 
portion 40 overlays and is connected to a mating flange-like portion 42 
formed on a bottom enclosure panel 44 which also forms a part of support 
platform assembly of the invention. As shown in FIGS. 3 and 4, a channel 
46 is formed in the peripheral portion of the enclosure panel and is 
defined by inner and outer spaced apart circumscribing walls 50 and 52 
which also form a part of the peripheral portion of the enclosure panel. 
As best seen in FIG. 4, a generally planar central wall 54 spans inner 
wall 50 and is preferably integrally formed therewith. Central wall 54 is 
provided with a plurality of indentations 54a (FIG. 2B), the purpose of 
which will presently be described. 
Receivable within channel 46 of enclosure panel 44 is a novel, 
strategically shaped reinforcement frame 57 (FIGS. 3, 4, and 6). 
Reinforcement frame 57 includes a pair of spaced apart, longitudinally 
extending structural beams or extrusions 57a and a pair of spaced apart 
transversely extending beams or extrusions 57b. As illustrated in FIGS. 2A 
and 5, beams 57a and 57b are interconnected by four uniquely configured 
corner assemblies 60. As best seen in FIG. 11, each corner assembly 60 
includes a central arcuate shaped, hollow portion 60a which is closed by 
end walls 60b. As indicated in FIGS. 5 and 11, end walls 60b abut the 
longitudinally and transversely extending support beams 57a and 57b when 
frame 57 is positioned within channel 46 of enclosure panel 44. Beams or 
extrusions 57a and 57b (are generally "C") shaped in cross section (FIG. 
11) and are preferably formed of a rigid, high strength, plastic or metal 
material as are the corner assemblies 60. As shown in FIGS. 3 and 4, beams 
57a and 57b each have an upper and lower segment 59a and 59b respectively 
and a vertical segment 59c. Segment 59a includes a generally planar upper 
surface 59d. Reinforcement frame 57 can simply rest within channel 46 or, 
if desired, can be secured within the channel by any suitable means such 
as by adhesive bonding. 
As illustrated in FIGS. 2B, 3, 4 and 6, a novel edge reinforcing frame 64 
is also receivable between peripheral flange 22c of cover 22 and wall 52 
of enclosure panel 44 in the manner shown in the drawings. As best seen in 
FIG. 2B, frame 64 includes a pair of longitudinally extending tubular 
members 64a and a pair of transversely extending tubular members 64b. 
Members 64a and 64b are interconnected by novel corner members 66. As best 
seen in FIG. 12, each corner member 66 includes an arcuate central portion 
66a having outwardly extending, fingerlike projection 67 which are closely 
receivable within tubular members 64a and 64b when the members are 
assembled in the manner shown in FIG. 2B. Reinforcing frame 64 can be 
constructed of a variety of moldable plastic materials such as polyvinyl 
chloride, polyethlyene, and butyrate and functions to effectively support 
and attractively trim out the edge portions of the platform assembly in 
the manner best seen in FIGS. 3 and 4. 
Another important feature of the apparatus of this latest form of the 
invention comprises anchor means for use in securely interconnecting leg 
assemblies 14 and 15 to the support platform. These anchor means are here 
provided in the form of a plurality of anchor plates 70 to which the 
folding legs of the table can be securely interconnected. Anchor plates 70 
are positioned within the previously identified, spaced-apart anchor plate 
receiving indentations 54a which are formed in the central portion of 
closure panel 44. More particularly, a pair of anchor plates 70a are 
received within centrally disposed indentations 54a while the remaining 
anchor plates are received within indentations 54a located proximate the 
side portions of the enclosure panel 44. 
To pivotally support leg assemblies 14 and 15 relative to the support 
platform, novel leg support means are provided. These leg support means 
here comprise four bearing plates or clamps 74 each of which includes. a 
concave portion 74a that is disposed between spaced-apart wing-like 
elements 74b. The two pairs of cradle assemblies are connected to 
enclosure panel 44 and to the side anchor plates 70 in the manner shown in 
FIGS. 3 and 4 by suitable connectors such as self-drilling and tapping 
threaded fasteners 76 which extend through wing-like portions through the 
central wall of enclosure panel 44 and into anchor plates 70 in the manner 
shown in the drawings. With this construction, the convex channels or 
central portions 74a of bearing plates 74 function as bearing means for 
rotatably supporting the extremities 78a of each of the horizontally 
extending, generally tubular shaped, axle-like members 78 which comprise a 
part of the leg assemblies 15 and 16 of the invention (FIGS. 2B and 4). 
Also forming a part of each of the leg assemblies 15 and 16 is a yoke-like 
member 80, the arms 80a of which are pivotally connected to the downwardly 
extending legs of each of the leg assemblies. Pivotally connected to each 
yoke 80 is a connector rod 82 which functions to pivotally interconnect 
yoke 80 with a plate-like member 84 which is, in turn, affixed by 
self-drilling and tapping threaded fasteners 86 to the central wall of 
enclosure panel 44 and to anchor plates 70a (FIGS. 2B, and 3). With this 
construction, the leg assemblies can pivot relative to support platform 22 
in the manner illustrated in the drawings. Various types of both fixed and 
pivoting leg assemblies can be connected to platform 22 and various types 
of mechanisms can be used to interconnect the leg assemblies with the 
platform. 
In assembling the leg assemblies to the support platform, the four bearing 
plates 74 are placed over the ends of the tubular members or axles 78 of 
the leg assemblies. This done, the bearing plates are then connected to 
the enclosure panel and to the side anchor plates using the previously 
identified threaded fasteners 76. Similarly, with the yoke assemblies 
connected to the legs in the manner shown in FIG. 3, plates 84 are 
connected to the enclosure panel and to the central anchor plates using 
the previously identified connectors 86. 
To complete the assembly of this first form of foldable table, a generally 
U-shaped, plastic trim strip 89 is slipped over the lower edge of flange 
22c of cover 22 in the manner shown in FIGS. 3 and 4. 
Turning to FIG. 7, still another form of the lightweight, high strength 
folding table of the present invention is there shown. The folding table 
of this latest form of the invention is virtually identical to the 
embodiment shown in FIGS. 1 through 6, but includes a different 
reinforcement frame 100 having reinforcement beams 100a and 100b which are 
generally box-shaped in cross section. This latest embodiment comprises a 
support platform assembly 12 and first and second leg assemblies of the 
character earlier described. 
More particularly, support platform 12 comprises a support member or cover 
22 which defines a work surface 22a and includes a peripheral side wall 
22c which circumscribes surface 22a and defines a downwardly depending, 
skirt-like portion of the character shown in FIG. 7. The enclosure panel 
44 and the reinforcement core 24 are identical to those previously 
described and frame 100 is disposed within channel 46 of the enclosure 
panel in the same manner as previously discussed. 
Turning next to FIGS. 8 through 10 still another form of the invention is 
there illustrated. This form of the invention is identical to that 
previously described, but includes a uniquely configured structural 
reinforcement core 102 of the character illustrated in FIGS. 8, 9 and 10. 
As there shown, reinforcement core 102 comprises a panel which is 
preferably vacuum formed or injection molded into the configuration show 
in FIG. 8, As indicated in FIGS. 8, 9 and 10, core 102 comprises a 
multiplicity of generally perpendicularly extending ribs 104 which are 
generally U-shaped in configuration. These ribs function in the same 
manner as the frustoconically shaped protuberances 34 previously 
described. 
More particularly, when core 102 is assembled with a support member 22 and 
an enclosure panel 44 of the character previously described so that panel 
102 is disposed between the enclosure panel and the lower surface of the 
support member ribs 104 will provide substantial structural support to 
support member 22. Additionally, core 102 is provided with a peripheral 
flange 102a, which is adapted to reside between the reinforcement frame, 
which may be of the C-shaped configuration shown in FIGS. 1 through 6 or 
of the box-shaped configuration shown in FIG. 7, so as to impart further 
structural strength and rigidity to the support platform of the invention. 
Having now described the invention in detail in accordance with the 
requirements of the patent statutes, those skilled in this art will have 
no difficulty in making changes and modifications in the individual parts 
or their relative assembly in order to meet specific requirements or 
conditions. Such changes and modifications may be made without departing 
from the scope and spirit of the invention, as set forth in the following 
claims.