CA2178123A1

CA2178123A1 - Lightweight plastic furniture

Info

Publication number: CA2178123A1
Application number: CA002178123A
Authority: CA
Inventors: Clifford Raab
Original assignee: Clifford Raab; Virco Mfg. Corporation
Current assignee: Virco Manufacturing Corp
Priority date: 1995-10-24
Filing date: 1996-06-04
Publication date: 1997-04-25
Also published as: ATE237972T1; US5694865A; JPH11513605A; KR19990067058A; EP0876116A4; DE69627707D1; EP0876116A1; EP0876116B1; US5868081A; CN1202806A; AU6848496A; WO1997015212A1; US6058854A; CA2235784A1

Abstract

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 typical-ly used in modern office complexes. The support platform embod-ies a novel structural reinforcement core of a unique configura-tion which is both lightweight and exhibits superior strength and durability 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.

Description

2t78123 .
LIGE~TWEIGE~T PLASTIC ~U~NllU~;
,, Pi~ld Or the Invention ~ he p~esent lnvention relates generally to plastic furni-ture. Nore particularly, the invention concerns a lightweight plastic folding table having a novel, structurally reinforced support plat~orm providing a worX surface.

Discussion or t~e Invention Lightweight furniture which exhibits superior structural characteristics is in wide demand for many industrial and insti-tutional applications. Entities having great need for such furniture lnclude schools, convention centers, hotels, factories, business offices and various ~.,v~:L.~ .tal entities. Particularly in demand are lightweight ~olding tables and lightweight modular units for use in of ~ices and the like which are readily portable an~ easily storable when not in use.
While many types of lightweight furniture have been suggest-ed in the past, a typical drawback of such furniture is a lack Or LLu~LuL~l integrity which tends to contribute to limited useful life and to ~requent structural failures. As a general rule, when the prior art ~urniture designers have attempted to correct the ~~LLU~d U~ n~ C in the prior art design6, the furni-ture becomes excessively heavy and unduly bulky. As will bc A~c~ cc~ in greater dOEtail in the paragraphs that follow, the thrust o~ the present invention is to provide lightweight, readi-ly portable ~urniture which embodies a unique ~tructural reln-forceme~t core that provide superior structural integrity to the furniture without unduly increasing its weight or b~1kinr~c~.

,,- 1 ~ Exemplary of typical prior art plastic folding tables are those described ln U. 5. Patent 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, sand-wiohed therebetween. Another example of a prior art foldlng table is that described in U. S. Patent No. 5,394,808 issued to Dutro et al. 'rhis 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. 5. Patent ~o.
5,271,338 issued to Bonham and in U. S. Patent no. 3,628,470 issued to De~ucas.

surmary of the lllventio~
It is an ob~ ect of the present invention to provide a light-weight, 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.
~ ore particularly, it is an ob~ect of the invention to provide a lightweight support platform of the aforementioned character which embodies a highly novel structural reinforcement core which is both lightweight and exhibits ~iuperior 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 further includeS
pivotally mounted legs that can be pivoted from an extended operationa~ position into a retracted storage and LLa~l~Y.~I L
position wherein they abut the reinforcement core of the support 217~123 platform .
~ Another ob~ect o~ the invention is to provide a lightweight folding tQble of the aforementioned character which is unusually strong, is highly reliable in use and has a long usefuL life.
Another ob~ect of the invention is to provide a llghtweight, high-strength foldable table of the oharacter described which i5 ,LLu~.l ed from readily available moldable plastic materials and one which can be efficiently and inexpensively manufactured in high volume.
Still -nother object of the invention i8 to provide a light weight folding table of the class described in the preceding p~ yl~hS which i5 highly attractive and easy tc operate.

8riof Descr$ptio~ of tho Dr~wi~gs Figure 1 is a generally perspective view of one rmhoSi ~
of the lightweight plastic furniture o~ the present invention shown there as a lightweight folding table.
Flgures 2A and 2B together comprise a generally perspective, exploded view of the folding table construction shown in Figure 1 Figures 3A and 3B together comprise enlarged bottom plan view of the folding table construction shown in Figure 1.
Figure 4 is an enlarged, cross-s~r~;nn;-l view taken along lines 4-4 of Figure 3 3 .
Figure 5 is an enlarged, cross-sert~nnRl view taken along lines 5-5 of Figure 3B.
Figure 6 is a greatly enlarged, top plan view of a corner construction of the folding table of the invention partly broken away to show internal construction.
Figure 7 is an enlarged, cross-s~r~;nn~l view taken along lines 7-7 of Figure 6.
Figure 8 is an enlarged, oross-~r~rn~l view taken along lines 8-8 of Figure 6.

Figure g is a generally perspective, ~ragmentary, eYplodec 217812~
vlew of a portion of the support platform of the inventlon whLch is used in the construction of the folding tahle shown in Figure 1.
Pigure lo is a generally perspective, exploded view illustrating the construction of one corner of the reinforcement frame of the folding table construction shown in Figure 1.
Figure 11 is a greatly enlarged ~CL, ' ' ry plan view of an alternate îorm o~ support member of the lnvention.
Figure 12 is a l._LI~5~ Lional view taken along lines 12-12 of Figure 11.
Figure 13 is a generally perspective view of an alternatc m~nt of the lightweight plastic furniture o~ the present invention .
Figure 14A and 14B together comprise a generally perspec-tive, exploded view o~ the folding table construction shown in Figure 13.
Figure 1~ is a generally perspective view of one of the corner f~ _~Gmhl ~~c of the table construction shown in Figure 13.
Figure 16 is a generally perspective, f.~LeshoL L~ned view of the structural core of the table construction of this altern~te m.~nt of the invention.
Figure 17A and 17B together comprise a bottom view of the table ~vll .LLl~Lion partly broken away to show internal . -Ill=,L-u~-tion .
Figure 18 is an enlarged, cross-sectional view taken along lines 18-18 of Figure 17A.
Figure 19 is an enlarged, cross-s~~ nA ~ view taken along lines 19-19 of Figure 17B.
Figure 20 is an enlarged fragmentary, plan view o~ the t~ble construction partly broken away to show intQrnal construction.
Figure 21 is a cross-sectional view taken along lines 21-21 o~ FigUre 20.
Figure 22 is a cross-sectional view taken along lines 22-22 o~ Figure 21.

Figure 23 is a ~L~,,s-~e_LLonal view taken along lines 23-23 of Figure 20.

D~scriptior of the Inve~tio~
Referring to the drawings 2nd particularly to Figures 1, 2A
and 2B, one form of the lightweight, high ~trength folding table of the present invention is there illustrated and generally designated by the numeral 12. The folding table of this form of the invention comprises a support platform assembly 14 and first and second leg asEemblies 16 and 18, each of which comprisos ~
pair of downwardly extending legs designated in Figure 1 as 20 and 22, which legs are pivotally connected to platform 14.
An important feature of the present invention is the unique-ly configured support platform 14 which is used in the construc-tion of table 12. F~eferring particularly to Figures 2A and 2B, this novel support platform can be seen to comprise a support member or cover 24 which defines a work surface 24a and a struc-tural reinforcement panel 26 (Figure 2B) which is rrnnGr~G~l to support member 24 in a manner presently to bc described.
As best seen in Figures 2A and 4, support member 24 includes a generally planar first or work sur~ace 24a as well as a second generally planar surface 24b which is spaced apart from surface 242. Additionally, support member 24 includes a peripheral side wall 24c which circumscribes first surface 24a 2nd defines a downwardly ~GrGn5inq, skLrt-like portion of the character best seen Ln Figure 2A. support member 24 can be c~ Lu~_Lcd from a number of different types of moldable plastic materials such as polyethylene, styrene, polyproplyline and like materials. E~owev-er, acrylonitrile butadiene styrene (ABS) is preferred.
An important aspect of the support platform c~llGLLu~:~ion of the present invention is the uniquely conf igured, relatively thin plastic reinforcement panel 26. As illustrated in Figures 4 and 5 rein~orcement panel 26 is interconnected wlth support member 24 ~ and ~unctions in a novel manner to provide substantial structural support to member 24 so that work sur~ace 24a can withstand substantial vertical loading. Panel 26 can also be ~ PLLU~.L~
from various moldable plastic materials o~ the character de-scribed in the preceding paragraph, but Once again ABS is pre-ferred. DPrPn~ng upon the material selected, panel 26 can be vacuum ~ormed, injection molded or molded in a number o~ other ways well known to those skilled in the art.
Referring particularly to Figures 2B and 5, the novel rein-i~orcement panel 26 can be seen to include a central portion 30 and a peripheral portion 32 which circumscribes central portion 30. The central portion i5 uniquely formed to provide a multi-plicity of spaced-apart, specially con~igured upstanding protu-berances 34. As shown in Figure 5, each protuberance 34 compris-es a base portion 34a, a vertically spaced-apart, generally circular-shaped closure wall 34b (Flgure 9~, and a tapered con-necting wall 34c which interconnects base portion 34a and closure wall 34b (Figure 5). ~hile protuberances 34 are shown in thc drawings as being generally ~rustoconical in 3hape, the protuber-ances can take on a wide variety o~ shapes. For example, top wall 34b o~ each protuberance, rather than being circular in shape, could be hexagonal or octagonal in shape should the de-signer 50 desire. ~e~erring particularly to Figure 9, it is to be noted that a multiplicity o~ web-like ~ LU._I U~:S 36 intercon-nect prctuberances 34 so as to provide additional strength to the rein~orcement panel. As seen by also re~erring to Figure s, a multiplicity of cavities 3a are provided intermediate protuber-ances 34 . cavities 33 are also generally rL U' Lo..~LliCal in shape and terminate in base olosure walls 38a.
The pleripheral portLon o~ ~he rein~orcement panel is also uniquely con~igured and, as illustrated in Figure 5, oomprises a ~irst channel 40 which is de~inecl by a downwardly extending , ., -generally "U" shaped wall portlon 40a which forms a part o~
~ peripheral portion 32 of the reinforcement panel. A second ch~nnel 42 i3 also formed in peripneral portion 32 of the struc-tural panel and is defined by a generally ~'U" shaped, upwardly extending wall 42a which also forms a part of the I peripheral portion of the reinforcement panel. As best seen in Figures 3A
and 38, both channels circumscribe central portion 30 o~ the reinforcement panel with second channel 42 also circumscribing channel 40 (see also Figure 2A).
Receivable within channel-shaped portion 40 is a generally rectangular shaped réinforcement frame 44 (~igures 2A and 5).
Reinforcement frame 44 includes a pair of spaoed apart, longitu-dinally eXtcnaing structural beams or extrusions 44a and a pair of spaced apart transversely extending beams or extrusions 44b.
As illustrated in Figure L0, beams 44a and 44b are inter~ nnf.r~
by four corner assemblies 48 of novel design, each of which ln-cludes a pair of outwardly extending tongues 48a and 48b.
Tongues 48a and 48b are closely receivable within openings 49 and 50 respectively which are provided in beamG 44a. In similar manner, each corner assembly 48 also inoludes outwardly extendlng tongue-like portions 48c and 49d which are receivable in corre-spondingly shaped openings 51 and 52 provided in beam 44b (see also Figure 6). Beams or extrusions 44a and 44b are preferably formed o~ a rigid, high strength, plastic material as are the corner AR~7nh~ 48. As shown in Figure 2A, a corner assembly 48 is provided at each corner of reinforcement frame 44 to pro-vide a closed frame of substantial strength. Reinforcement fr~me 44 can simply rest within channel 40 or, if desired, can be secured within the channel by any suitable means such as by adhe-sive bonding.
Receiyable within channel-like portion 42 o~ the reinforce-ment pahel is a generally rectangular shaped edge support frame 56. As shown in Figure 2B, frame 56 also comprises a pair of sp~ced-apart, longitudinally extcnding beam-like members or extrusions 56a and a pair o~ transversely ~Yl-on~;ng bean-like extrusions or structural members 56b. Members 56a and 56b are ~oined at their ends to arcuately shaped, resiliently deformable corner members 58. Corner members 58 comprise cushioning means for r~ h~nn;ng impact forces imposed on the support platform during transport end storage and are preferably formed of a resiliently deformable, relatively hard elastomer such as natural or synthetic rubber. If desLred, corner members 58 can be inter-connected with beams 56a and 56b in any sultable manner such adhesive bonding. Similarly, edge support frame 56 can simply rest within channel 42 or, i~ desired, can be secured in place within the channel by any suitable means such as adhesive bond-ing. Reinforcement beams 44a, 44b, 56a, 56b can be constructed of various plastics of the character previously d; ~c~-cc~7 but onoe again ABS comprises the material of choice.
As illustrated in Figures 2B and S, a resiliently deformable sealing means or trim frame 60 is also receivable within channel 42 in the manner shown in the drawings More particularly, as best seen in Figures 7 and 8, trim member 60 includes a first upstanding finger-like pro~ection 60a which is disposed between edge frame 56 and outer wall of the channel-defining walls 42a of panel 26. ~o securely wedge frame 56 into channel 42 in the manner shown in Figures 8 and 9, a plurality of outwardly extend-ing rib-like protuberances 60c are provided on pro~ecticn 60a.
~rim member 60 also inoludes a second, upwardly extending, fin-ger-like pro~ection 60b which i8 spaced from pro~ection 60a so as to be closely receivable over a portion of skirt portion 24c o~
support member 24 when member 24 i5 A~~ over panel 26.
Irim or sealing frame 60 can be constructed of a variety of moldable plastic materials such as polyvinyl chlorido, polyeth-lyene, and butyrate and functions to seal and attractively trim out the lower edge portion of the platform assembly in the manner ~178123 hest seen Ln Fisure S.
~ Another important feature of the appar~tus of the present invention of the invention comprises anchor means for u~se in securely interconnecting leg assemblies 16 and 18 to the support , platform. These anchor means are here provided in the form of a plurality of anchor plates 65 to which the folding legs of the table can be securely interconnected In the ~ m~nt of the invention shown in the drawings, anchor plates 65 are positioned within transversely extending, longitudinally, spaced-apart anchor plate receiving grooves 63 which are formed in central portion 30 oî rein~rcement panel 26 (Figure 2B~. More particu-larly, those anchor plates designated in the drawings as 65a are received within the grooves designated in the drawings as 63a, while the anchor plates deslgnated as 65b are received within the grooves identified by the numerals 63b. A centrally disposed ~nchor plate 65c is closely received within a central groove 63c ~ormed in reinforcement panel 26. Groove 63c functicns to re-ceive the ground engaging extremities 16a and 18a of the leg mhli~s when the leg :~~~~mhl~.s are retracted in the manner shown in the Figure 2A and 2B.
Anchor plates 65 can be constructed of thin sheet metal such as steel or aluminum, and each is providcd with downwardly ex-tending end walls 67, which depend downwardly over the ~ v~
edges of grooves 63 tFigure 4). As can be seen by referring to Figures 3B, 4, and 5, anchor plate 65a is received within channel 63a and ls secured in place by fastenErs such as threaded bolts 69 which extend through the base wall 63ab which defines the bottom of channel 63a and then through the anchor plate 65a in the manner shown in Figure 5.
~ o pivotally support leg assemblies 16 and 18 relatlve to the support platform 14, novel ~eg support means are provided.
~hese lég support means here comprise ~our cradle-like support assemblles 76 each of which includes a concave portLon 76a that 21~8123 ls disposed between spaced-apart wing-llke elements ~6b. The two pairs of cradle assemblies are connected to base walls 63ab in the manner shown in Figures 3A, 3B and 5 by suitnble connectors such as the previously identi~ied threaded connectors 69 which extend through wind-like portions 76b, through base~ wall 63ab, and into anchor plates 65a in the manner best seen in Figures 3B
and 5. Also forming a part of each cradle assembly 76 is an end plate 76c which is connected to reinforcement panel 26 as well as to reinforcement frame 44 by means of elongated threaded fasten-ers 79 (see also Figure 5). More particularly, as best seen ln Figure 4, connectors 79 extend through end plate 76c, through Wall 40a of panel 26, through cnd w~lls 67 of the anchor plates and ehen into protuberances 45 which are forL3ed internally of frame assembly 44. Cradles 76 along with convex channels 26c ~Figure 5) formed in panel 26, function ~s bearing means for rotatably supporting the extremities 30a of each of the horizon-tally extending, generally tubular shaped, axle-like members 80 which comprise a part of the leg ~':q~mhl i eR 16 and 18 of the invention (Pigure 2).
Also forming a part of each of the leg assemblies 16 and 18 iB a yoke-like member 82, the arms 82a o~ whlch are pivotally rnnnl~ctl~/l to the downwardly extending legs of each of the leg ~ lR/~mhl; ~C. Pivotally connected to yoke 82 is a connector rod 84 which functions to pivotally interconnect yoke 82 with a pl~ee-like member 86 which is, in turn, affixed by ehreaded fasteners 86a to base wall 63bb of channel 63b ~nd to anchor plates 65b (Figures 3A and 3B). With this construction, leg assembly 16 can pivot in the manner illustrated in the drawings from its first extended position shown in ~igure 2B to its collapsed stowed position shown in Figure 3B. Similarly leg assembiy 18 can pivot from an extended position into~ the stowed position shown in Figure 3A. It is to be understood that various types of both ~ixed and pivotinq leg a~<:r'mhl i eS oan be connected to platform 14 and various types of m~ h~n;~-c can bR used to lnt~L~.,..,~e~l. thc leg A~ .C with the platform.
I:n constructing the support platform of the invention, reinforcement frame 44 is A~COmhl~orl together in the manner pre-, viously descr~bed with the four corner members 48 being securelyinterconnected wlth members 44a and 44b in the manncr illustrated in Flgure 10. As shown in Figures 4 and 5, the frame ~cc.~mhl~e is then seated into channel 40a. ~Jith frame 44 thusly seated, anchor plates 65a, 65b, and 65c are positioned within their reGpective anchcr-plate receiving grooves 53a, 63b, and 63c in the manner also shown in ~igures 4 and 5.
Next, the four cradle assemblies 76 are placed over the end6 80a of the tubular members or axles 80 of the leg :~c~.mhl ;F.c in the manner shown in Figures 3A and 3B and the cradle ::lcc~mhl; ~
are then ~nnn~ rl to the structural panel using the previously identified threaded fastener~ 69 and 79. In this regard, lt ls to be noted that, as previously mentioned, the interior wall surface 44i of frame assembly 44 is provided with portions 45 of substantially increased wall thiclcness which receive the self-tapping, threaded connectors 79 (Figure 4~. This construction provides extra rigidity to the structure to enable smooth, vibra-tion rree rotation of the axle mem}~ers 80 within the convex por~ions 26c of the reinforcement panel and the central portions 762 of the cradles. To complete the assembly of the various ~LLU~l~ULa1 components of support 14, rim assembly 56 is inserted into peripheral channel 42 in the manner shown in Figure 5.
To complete the alternating protuberance and cavity pattern of the central portion of the reinforcement panel and to provide a core assembly in which the ~rc~nS~n~ protuberances substantlally cover the entire upper surface of the reinforcement core, spe-cially configured reinforcement ~egments 90 are emplaced within channels 69 formed in the anchor plates ~see ~lgures 2~ and 9).

So as to provide structural contlnuity, segments 90 have a sur-,,.- 11 _, .

21~8123 face configuration similar to that of the centr~l portion 30 of ~ p~nel 26. More partlcularly, each of he segments 90 has a plu-r~lity Or upst~nding protuberances gOa whioh are slmilar to protuberances 34 with each having a base portion, a top closure wall 90b, and a side wall 90c which interconnects thc base por-tion and th- top closure wall 90b (Figure 2A and 9).
With reinforcement segments 90 in position within the chan-nels formed in the anchor plates 65, a suitable adhesive is sprayed, painted, rolled or otherwise deposited on closure walls 34b and 90b of the reinforcing panel and of the segments 90a.
Cover 24 is then placed over the reinforcement panel AC~' hl~r.e so that the central portion of undersurface 24b of the support member rests upon the adhesive coYered closure walls 34b and 90b of protuberances 34 and 90a. It is to be undcrstood that a number of different kinds of readily commercially available adhesives can be used to securely bond support member 24 to the protuberances 34 and 90a which make up the structural core o~ the reil.~.,L~ L panel.
Following the bonding step, trim member 60 is mated with the A~:s~mhlAqe by inserting projection 60a into the circumferentially extending space 93 formed between ~rame 56 and outer wall 42a of the reinforcement panel. Member 60a is secured in place within channel 42 by the previously identified resiliently deformable protuberances 60c which securely grip the inner wall of the longitudinally extending and transversely extending members 56a and 56b of frame assembly 56. As shown in Flgure 5, with pro~ec-tion 60a in position within gap 93, the outer lip, or pro~ection 60b, will circumscribe and frictionally engage skirt 24c of sup-port member 24 thereby neatly and attraotively trimming the rA~rF:~A~ of the support platform.
~ eferring next to Figures ll and 12, an alternate form of support platîorm of the present invention is there illustrated.

this form of support platform is identical in all respects to .
I

platform 14 and is constructed in the same manner using the same ~ components as previously described save thQt a second partlal reln~~.L.. ~ L panel i26a ls affixed to a full panel 126 which is of identical construction to panel 26 of the prevlously desoribed ' ~~ L. Panels 126 and 126a are Acs~hl~/l together in a bacX-to-bac3c relationship in the manner shown ln Plgure 12. The central por lon of each of the panels 126 and 126a is provided with a multlpliclty of upstandlng, generally frustoconical shaped protuberances identified in Pigure 12 by the numerals 134 and 134a. Each of the protuberances 134 has a base portion 135, a closure wall 137, and a connecting wall 139 illLeL~ le~ Ling base portion 135 and closure wall 137. Disposed intermediate protu-berances 134 are generally ~rust~ron~rAlly shaped cavities 141.
In Acc~mhl ;nr the plat~orm of this latest form o~ the lnven-tion, full reinforcement panels 126 and partial relnforcement panel 126a are interconnected by bonding the closure walls 137 of panel 126a to the base walls 143 of cavlties 141 of panel 126.
After panels 126 and 126a have been thusly lnterrrnn~r~o~, cover 24 is placed over the assemhlage thus formed and is bonded to panel 126 along the closure walls 137 of panel 126. As ls appar-ent from a study of Figure 12, thls double reinforcement p_nel _~11 LLu~ Lion provides additional strength to the support platform and enables the upper or work surface of support member 24 to carry loads of very large magnLtude.
Turnlng to Figures 13 through 23, another form of the llghtwelght, hlgh strength folding table of the present lnventlon ls there shown and generally designated oy the numeral 152. The folding table of this latest form of the invention is similar to the ~--"ho~T~ nt shown in Figures 1 thrDugh 10 and comprises a support platform assembly 154 and first and second leg Aec~ OC
156 and 15-3, each of which compri~es a pair of downwardly extend-ing legs designated in Figure 13 as 160 and 162, which legs are pivotally connected to platform 154.

~ 21~8123 Referrlng particularly to Figures 14A and 14B, support platform 154 can be seen to comprisc a support member or cover 164 which defines a work surface 164a and a structural reinforce-ment core 166 which is connected to member 164 in a manher pre-sently to be described.
As before, support member 164 includes the generally planar first or work sur~ace 164a as well as a second generally planar surface 164b which is spaced apart from surface 164a ~see Figure 19). Additionally, support member 164 includes a peripheral side wall 164c which circumscribes rirst surface 164a and defines a downwardly ~ r~nrl;n~ skirt-like portion of the character best seen in Flgure 14A. Support member 164 can be constructed from a number of different types of moldable plastic materials such as polyethylene, styrene, polyproplyline and like materials. Howev-er, acrylcnitrile h~ nG styrene (ABS) is preferred.
An important aspect of the support platform construction of this latest form o~ the invention is the uniquely configured, structural reinforcement core 166. As illustrated in Figures 18 and 19 reinforcement core 166 is internnnn~r~ with support member 164 as by adhesive bonding or the liXe and functions in a novel manner to provide substantial structural support to this member so that work surface 164a oan withstand substantial vorti-cal loading. Core 166 can also be .~ ,LLu~Led from various moldable plastic materials, but once again ABS is preferred.
D~r~nr~n~ upon the material selected, core 166, liXe panel 26, can be vacuum formed, in~ection molded or molded in a number of other ways well known to those skLlled in the art.
Referring particularly to Figures 14A, 16 and 18, the reinforcement ccre 166 can be seen to include a central portion 170 and a peripheral portion 172 which circumscribes central por-tion 170. ' The central portion is uni~uely formed to provide a multlplicity of spaced-apart, specially configured upstanding .

protuberances 174. As best seen in Figure 18, each protuberance ~ 174 comprises a base portion 174a, a vertically spaced-apart, generally circular-shaped closure wall 174b (Figure 16), and a t2pered t~-nnot~in~ wall 174c which interconnects base portion 174a and closure wall 174b (Figure 18). While protuborances 170 are shown in the drawings as being generally frustoconical in sh~pe, as before, the protuberances can take on a wide variety of shapes. ~s indicated in Figure 16, a multiplicity of web-like ~.-LU~,LUL~S 176 interconnect protuberances 174 so as to provide additional strength to the reinforcement core. As seen by also rererring to Figure 18, a multiplicity o~ cavitles 178 are pro-vided intermediate protuberances 174. Cavities 1.78 are also preferably generally frustoconical in shape and terminate in base closure walls 178a.
~ he peripheral portion of core 166 comprises a generally vertically extending, circumscribing wall 180 and a circumscrib-ing flange-like portion la2 which is integrally formed with wall 180. As best seen in Figure 18, flange-like portion 182 overlays and is connected to a mating flange-like portion 183 formed on a l~ottom enclosure panel 186 which also forms a part of support plat~orm assembly 154 (see also Figure 14B~. As shown in Figure lgB, a channel 188 is forned in the peripheral portion 190 of the enclosure panel and is defined by inner and outer spaced apart circumscribing walls 190 and 192 which also form a part of the peripheral portion 19 of the enclosure panel. As best seen in Figure 14B, a generally plan~r central wall 194 spans inner wall 190 and is preferably integrally formed therewith (see also Figures 18 and 19). Central wall 194 is provided with P plurali-ty of indentations 194a, the purpose of which will presently be Receivable within channel 188 of enclosure panel 186 is a generaliy rectangular shaped reinforcement frame 197 (F~ gures 14 and 18~ einforcement frame 197 includes a pair of spaced apart, longitudin~lly extending structural beams or extrusions ~ 197a and a pair of spaced apart transversely extending beams or extrusions 197b. As illustrate~ in Figures 14A and 15, beams 197a and 197b are interconnected by four corner ;~c- ~ lie5 198 of , novel design, each of which includes a pair of outwardly extend-ing tongues 198a and 198b (Figure 15~. To~gues 198a and 198b are closely receivable within generally "U" shaped channels 200a and 200b which are formed in beams 197a and 1~7b. Eaoh oorner assem-bly 198 also includes a central arcuate shaped, hub-like portLon 198c from which tongues 198a and 198b extend. As best seen in Figure 23, port:ion 198c terminates in an upper wall 199 which engages the lower surface 164b of cover 164 when frame 197 is positioned within channel 188 of enclosure panel 186. Beams or extrusions 197a and 197b are preferably formed of a rigid, high strength, plastic material as are the corner ~c~ 198. As shown in Figure 14A, a corner assembly 198 is provided at each corner of reinforcement frame 197 to provide a closed frame of substantial strength. Reinforcement frame 197 can simply rest within channel 186 or, if desired, can be secured within the channel by any suitable means such as by adhesive bonding.
Similarly, tongue 197a and 197b can simply rest within "U" shapea channels 200a and 2~0b, or, if desired, can be secured in place within the channels by any suitable means such as adhesive bond-ing .
As illustrated in Figures 14EI, 18 and 19, a resiliently deformable seallng means or trim frame 204 is also receivable between peripheral flange 164c of cover 164 and wall 192 of enclcsure panel 186 in the manner shown in the drawings. As be~ore, trim member 204 includes a central portion 206 which is disposed between flange 1640 and wall 192 of enclosure panel 186.
Trlm membe~ 204 also includes an ~upwardly extending, finger-like pro~ection 207 which is spaced from central portion 206 so a6 to be closely receivable over a portion of flange 164C of cover ~81~13 ~: ~
memOer 164 when member 164 is ACC~ over core 166 and enalo-~ sure panel 186. As before, trim or seallng frame 60 can be constructed o~ a variety o~ moldable plastLc materials such as polyvinyl chloride, polyethlyene, and butyrate and functions to seal and attractively trim out the lower edge portion of the platform assembly in the manner best seen in Figures 13 and 20.
Another important feature of the apparatus of this latest form o~ the invention comprises anchor means for use in securely inter~ nna~l in~ leg assemblies 160 and 162 to the support plat-form. These anchor means are here provided in the form of a plurality of anchor plates 210 to which the folding legs of the table can be securely interconnected. Anchor plates 210 are positioned within the previously identified, spaced-apart anchor plate recsiving indentations 194a which are formed in the central portion 30 o~ closure panel 186 ~Figure 14B). I~ore particularly, a pair of anchor plates are received within centrally disposed indentations while the remaining anchor plates are reoelved within indentations located proximate the side portions o~ the enclosure panel 186.
To pivotally support leg A~ 156 and 158 relative to the support platform, novel leg support means are provided.
These leg support means here comprise four bearing plates 214 each of which includes a concave portion 214a that is disposed between spaced-apart wing-like elements 214b. The two pairs Or cradle AC.' ' lif": are connected to enclosure panel 186 and to the side ahchor plates in the manner shown in Figures 14B, 17B, 17A
ana 17B and 18 by suitable ~ e~ s such as rivet-like connec-tors 216 which extend through winq-like portions through the centr~1 wall of enclosure panel 186 and into anchor plates 210 in the manner best seen in Figures 18 and 19. With this ~ JII~Lr 1l~
tion, the Iconvex channels or ce~ltral portions 214a of bearing plates 214 function as bearing means for rotatably supporting the ~Ytr-loities ~ f ea~ ~t t~e tori~ont~lly ~xtendlng, ge~er-llly - 21~8123 tubular shaped, axle-like members 218 which comprise a part of the leg assemblies 160 and 162 of the invention (Figures 17A and 17B) .
Also ~orming a part of each o~ the leg AC~ C 160 and 162 is a yoke-like member 220, the arms 220a of which are piv-otally rnnnr-r~r-A to the downwardly extending legs of each of the leg Ar- 'l;rc. Pivotally connecte~ to each yoke 220 is a con-nector rod 222 which functions to pivotally interconnect yoke 220 with a plate-like member 224 which is, in turn, affixed by threaded fasteners 226 to the central wall o~ enclosure panel 186 and to anchor plates 210 (Figures 17A, 17B, and 18). With this ,.l.Lion, the leg A~cr~hl~l~c can pivot relative to support platform 154 in the manner illustrated in the drawings and in the manner described in connection with the ~-imPnt of Figures 1 through 10. As before, various types of both fixed and pivoting leg Accrlnhl ~ ,.c can be connected to platform 154 and various types o~ ~ An~c can be used to interconnect the leg assemblies with the platform.
In assembling the leg assemblies to the support platform, the four bearing plates 214 are placed over the ends 218a of the tubular members or axles 218 of the leg assemblies. ~his done, the bearing plates are then connected to the enclosure panel and to the side anchor plates using the previously identified thread-ed fasteners 216. Similarly, with the yoke A~ C rnnn~r~
to the legs in the manner shown in Figures 17A and 17B, plates 224 are connected to the enclosure panel and to the central anchor plates using the previously identified connectors 226.
Elaving 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 modifica-tions 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 ~rom the scope and spirit of the invention, as set ~orth in the ~ollowing claims.

Claims

1. A lightweight, high-strength support platform for use in constructing plastic furniture, comprising:
(a) a support member having a generally planar first surface and a spaced apart second surface; and (b) a reinforcement core connected to said support member, said core having a first surface provided with a multiplicity of specially configured, outwardly extending protuberances covering a substantial portion of said first surface of said panel, each said protuberance including:
(i) a base portion;
(ii) a spaced apart closure wall; and (iii) a connector wall interconnecting said base portion and said closure wall; and (c) enclosure means connected to said support member for enclosing said reinforcement core between said enclosure means and said support member.

2. A platform as defined in Claim 1 in which said enclo-sure means comprises an enclosure panel having a channel formed therein.

3. A platform as defined in Claim 2 further including at least one reinforcement beam disposed within said channel of said enclosure panel for substantially spanning said enclosure panel.

4. A platform as defined in Claim 2 further including a reinforcement frame disposed within said channel of said enclo-sure panel.

5. A platform as defined in Claim 2 in which said protu-berances are substantially frustoconical in shape.

6. A platform as defined in Claim 2 in which said rein-forcement panel further includes a multiplicity of webs extending between said protuberances.

7. A platform as defined in Claim 2 in which said rein-forcement panel further includes a multiplicity of specially configured cavities disposed intermediate said outwardly extend-ing protuberances.

8. A lightweight, high-strength support platform for use in constructing plastic furniture, comprising:
(a) a support member having a generally planar first surface having a peripheral portion and a spaced apart second surface; and (b) a plastic structural reinforcement core connected to said support member, said core having a central portion and a peripheral flange circumscribing said central por-tions, said central portion being provided with a multiplic-ity of specially configured protuberances each comprising:
(i) a base portion;
(ii) a spaced apart closure wall; and (iii) a tapered connecting wall interconnecting said base portion and said closure wall;
(c) an enclosure panel connected to said peripheral flange of said core; and (d) a reinforcement frame disposed between said core and said enclosure panel.

9. A support platform as defined in Claim 8 in which said enclosure panel includes a central portion and a channel shaped portion circumscribing said central portion, said reinforcement frame being disposed substantially within said channel-shaped portion.

10. A support platform as defined in Claim 8 in which said reinforcement frame comprises a pair of longitudinally extending reinforcement beams, a pair of transversely extending reinforce-ment beams and corner members interconnecting said longitudinally extending reinforcement beams.

11. A support platform as defined in Claim 8 further in-cluding a pair of leg assemblies pivotally connected to said support platform for movement between a first extended position and a second retracted position.

12. A supporting platform as defined in Claim 11 in which said enclosure panel further includes anchor means for connecting said leg assemblies to said enclosure panel.

13. A support platform as defined in Claim 12 in which anchor mean? comprises a plurality of metal anchor plates.

14. A support platform as defined in Claim 13 in which said enclosure panel is provided with a plurality of spaced-apart anchor plate receiving indentations and in which each of said pair of leg assemblies includes a yoke-like member connected to a selected pair of said anchor plates.

15. A lightweight, high-strength support platform for use in constructing plastic furniture, comprising:
(a) a support member having a generally planar first surface having a peripheral portion and a spaced apart second surface; and (b) a plastic structural reinforcement core connected to said support member, said core having a central portion and a peripheral flange circumscribing said central por-tions, said central portion being provided with a multiplic-ity of generally frustoconically shaped protuberances;
(c) an enclosure panel connected to said peripheral flange of said core; and (d) a reinforcement frame disposed between said core and said enclosure panel, said reinforcement frame being disposed substantially within said channel-shaped portion and comprising a pair of transversely extending reinforce-ment beams and corner members interconnecting said longitu-dinally extending reinforcement beams.

16. A support platform as defined in Claim 15 further in-cluding a pair of leg assemblies pivotally connected to said support platform for movement between a first extended position and a second retracted position.

17. A supporting platform as defined in Claim 16 in which said enclosure panel further includes anchor means for connecting said leg assemblies to said enclosure panel.

18. A support platform as defined in Claim 17 in which anchor means comprises a plurality of metal anchor plates.

19. A support platform as defined in Claim 18 in which said enclosure panel is provided with a plurality of spaced-apart anchor plate receiving indentations and in which each of said pair of leg assemblies includes a yoke-like member connected to a selected pair of said anchor plates.

20. A support platform as defined in Claim 18 further including a yieldably deformable plastic trim strip circumscrib-ing said support member.