CA1282680C - Knock-down furniture coupling device - Google Patents

Abstract

Abstract of the Disclosure An article of knock-down furniture that can be easily assembled by an end-user comprises a plurality of pieces and contact joint arrangements that prevent unwanted separation of the pieces, while permitting the pieces to rotate and flex relative to each other. The contact joint arrangements also have lateral flexibility to permit the pieces to be coupled and shaped into a contour. The contact joint arrangement has a flexible tube that is extended through a continuous bore through each of the pieces. A hanger bolt is threaded into each end of the tube. A cap nut is threaded onto each hanger bolt and is in bearing contact with the end pieces. Each of the cap nuts are tightened against the end surface of the end pieces in order to place the tube in tension. The pieces are, consequently, held in longitudinal compression between the two cap nuts, while remaining free to rotate about the longitudinal axis of the tube. The hanger bolt and cap nut arrangement can be replaced by a screw assembly threaded into each end of the tube and contacting the end surfaces of the end pieces. The screw assembly in one end of the tube is threaded into the tube through a hole or notch cut near the particular end of the tube.
Once the screw assembly has been engaged through the hole or notch, the excess lead portion of the tube can be separated from the tube. Additionally. the screw assembly, or the hanger bolt and cap nut arrangement, at one end of the flexible cube can be replaced by a restraining element situated in fixed relationship with the tube. such as a molded stop or a cotter pin inserted through a transverse hole in cut one end of the tube.

Description

XNOC~-DOW~ FUR~ I ~URE COuPLIN~ DEVICE

~ackqround of the lnvencion This inven~idn relates Co dn ar~icle o~ knock~doWn ~urniture that c'an be easily assembled b~ the end-user.
~ rticles o~ niture that consis~ o~ several pieces, each capable of ro~ation relative to each other, a~e w~ll known. ~ typic~l example i~ ~he ~olding chair. O~e ~ype of ~olding chai~, known as ~knock-down~ ~urniture, h~
several pieces making up ~he seat, back ~nd legs oE the chalr. In a ty~ical desi~n, each piece has a bore through which a mecal rod is passed. Each pie~e i strung on this rod li~e beads on a stri'ng until the full cornplement o~
pieces~~hàs be-~n---reached to cc~a~e a-port~on~ he chaLr.
The pieces are held in pl~c~ on che rod by some fasCenin~
means at the ends of the cod. When the article of ~u~ ure is com~lece~y a~sembled, e~ch por~ion vf the chair is capable of cocation relative to each other, thereby allowing the ~nock:down c~ai.r tv fold out inco an oeen posi~ion ~or use, or to fold in~o a ~los~d compact positi`on suitahle for stor~e.
When the article o~ furni~ure has some contouf to its seat or ba¢k por~ions, th~ metal rod ha~ been replaced by metal wire, suc~ as 1~ y~ugc ~ence wire. The ~lexibiliCy o the wire allows it ~o confo~ln to this oon~our. This transverse ~lexibili~ necessd~y when the corttoured article of furniCuce is ~olded into iCs closed posicion.

~e wice is typ~cdlly bent ar the ends and d~ivcn b~ck in~o the end piece~. A knock-down chair o~ chi~ d~ig~
u6ually ha6 to be assembled by the manu~acturer ~ecause the procedure and ~0016 required are beyond the means of ~he average con~ume~.
A common problem with mo~t knock-down furnituLe i~ems is tha~ they are;not dasigned to be ea6ily assembled by the end-user. Pre~assembly of ~he ~u~n.iture by the manu~actureL i6 typically required, the~e~y increasing the production and shipping costs of the item. ~In ~ddition.
the end-user cannot easily adjus~ the pre-a6s~mbled urnitu~e should the item become 1006e. This inven~ion addresses these proble~s of ease of a~embly, ease of adjustment and cost-effectivenes6. by replacing the u~e o~
me~al rod or ~etal wire ~o couple the pieceS o an article o~ knock-down furnit~re.

~ 3 Summary o~ che Znvencion Described brief1y, in a typical em~odi.ment o~ ~he p~esent invention, a kit is compri ed of a plurality o~
pieces that, when assem~led, ~orm an ar~icle of knock-down fu~nitule. In the assembled ~onfiguration, the pieces are combined at a pl~rality of hinge ar~angements, each hinge arrange~ent hav~g a ~irst ~nd a second end piece and a selection of pieces sandwiched between these end piece6.
~n aligned bore extends through ea~h of the plurality o~
pieces a~ each of the hinge a~r~n~em~nt0. A~ each of the hinge arrangements a plasti~ ~ub~ is extended through each of the aligned bores. The tube has a leng~h slighCly ~horter than the efective length o~ the aligned bore. A
hanger bolt is threaded in~o each end of the plas~ic tube.
p~ior to assembly. A c~p nu~ is th~eaded onto the exposed th~eads o each h~nqe~ bol~, once the pl~stic tube has been loca~d within the aligned bo~e in each of the hinge arr~ngements. The cap nuts at ea~h end o~ the plas~ic tube are in bearing contac~ with the end pieces, and are tightened against these end Pieces in order to place t~e tube in tension. The furnituLe piece~ are, consequently.
held in longitudinal compression be~ween the two cap nut~, while ~emainin~ ~ree ~o rotate about ~he longi~udinal axi~
o~ the tu~e. Each elemen~ o~ the particular article of knock-down furniture, e.g.. ~he 6eat, back and legs in the c~se of a chai~ thus combined and interfaced u~ing this tube assembl~ a~ each hin~e ar~angemen~ in such a manner t~at the article of ~urnitu~e is fully collapsib~e in a closed position, and ex~endable to i~s normally operative arrangement in an open position.

B~ie~ DescriPtion of_~he ~awinq~

FIG. 1 is per~pective view of an article o~ knock-down fu~niture e~bodying ~he preRenr invention, ~hown in the open posi~ion.
FIG. 2 is a perspective view o~ the ar~icle of fuLniture of FIG.~ 1, shown in che closed po~ition.
FIG. 3 is a~enlarged exploded ~iew o~ a ~on~ac~ 30int o~ the ~rticle o~ furniture o~ FIG. 1.
FIG. 4 is ~n enlarged front elevational view of ~he contact joint in FIG. 3, shown in the a~embled con~i~uration.
~ IG. 5 i~ an enlarged ccoss-sectional ~iew o~ a Roction of the section S-5 o~ ~IG. 4, viewed in ~he direc~ion o~ the arrows.
FIG. 6 is an enlarg~d cross-sectional view o~ a porti~n o~ a second embodiment of the pLe ent inven~ion showing one end of ~he means or coueling a plurali~y o~
pieces in the ~s~embled posi~ion and ano~her ènd in the unassembled con~igura~ion.

~ iment Fo~ the purposes of promoting an ~nde~standing of the principles o~ the inven~ion, ~eferense will now be made to the embodiments illustrated in the drawing~ and s~ecific lang~ge will oe used to describe the same. It will nevertheles~ ~e ~ndelstood that no limi~ation of ~he sco~e of the inventio~'is thereby intended, such alterations and ful~her modifica~io~ in the il~u6trated de~ices, and such ~ur~he~ applications of the pcinciples o ~he inv~ntion a~
illujtrated therein ceing contempl~ted a6 would normally o~ur to one skilled in the art to which ~he invention rela~es, In one embodiment of this invention, an article o~
knock-down fu~nituce 5, shown in F'IG. 1 in the ~sse~bled con~iguration, com~ri&e~ a pluralit~ of pieces 8. ~hese ~iece~ ~ are ormed to con6titute ~he elements oF thi~
article of furnitu~e - namely, ~he legs. sea~ and back o~
the chair. T~e pieces are held in ~his con~igucation by a numbe~ of conta~t ioin~ arLangements 18, each adjus~ably constrained against end pieces, such as pieces 6 a~d 7 in ~G. 1. ~ach contac~ joint a~rangement is ~lexible ~o a}low the pieces to be ~ocmed into a contour 19. In addition, the eontact joint aLrangement is designed to allow the pieces to rotate celative to each o~her so that the a~ticle of ~ucnituc~ 5 can be folded into a closed position, as shown in ~IG. 2.
~ he basic ele~ents o~ the cont~ct joint arran~ement ale illustrated in the exploded vie~ o~ FIG. 3. An aligned bore ~9 extends thLough each of the pieces 6, 7 and ~. A ~lexible plas~ic ~ube lo has hanger bolts 20 and 25 threaded in~o ea~h end o~ ~he tube. The tuhe and han~er bo~ 8~mbly 1~ pa~ed Chrollgh th~ bore ~9. ~ c~p nut 30 i6 ~h~eaded onto each hany~r bolt 20 and Z5 at cach end o~ the ~cube. Th~ cap nuts a~ each end are Cighten~d against the oute~ surface 57 and 52 o~ the end piece~ 6 and 7, respecti~ely, as shown in FIG. 4. A6 the cap nut~
~re Ciqhtened, t~e ~be 10 is plac~d in tension. whi~h i~
reacted a~ a compressi~e or~e ~hrough ~he cap nut~ 30 to re~train the piece6 6, 7 and B. The eieces contact eac~
other at joints 53. The contact joint arra~gement can flex at t~es2 joints 53 to allow the pieces to assume a contou~, or .to change conto~ when the article of fucniture is folded into its closed co~figu~a~ion. ~he amount of tension in the tube 10 dete~mines the ~au~ness of ~he contact joint acrangement and, con~equently, the rigidit~ of the contour ~orm~d ~y ~he piece6 6, 7 and 8.
The details o~ the contac~ joint ar~angemen~ are shown in FIG. 5. Fo~ purposes of cla~ity, only a ~i~s~ end piece 50 and a ~e~ond end piece 55 are shown, although it is understoo~ that a nu~nbe~ of similar pieces can be sandwiched between these end ~ieces in a final confi~uration. The pieces 50 and 55 each have a bore 51 and 56, respec~ively, with the central axis o~ the bores in ali~nment on a common a~is 4a to form the common bore 49. In the pre~en~ embodiment, the flexible tube lo having an inner ci~cum~erential sur~ace ~1 and ~n outer sur~ce 12, is cut to a length slightly shortee ~han the combined length of` the common bore 49, ~o that Che Cube can be lo~ated ~ully within the combin~d ~ore when the pi~ces a~e ~t~ung togethe~, a~ illus~ated in FIG. ~.

~2~
So~e mean~ o~ restraining the tube within ~he ~ore 18 provided. Typically, a hangec bolt ZO i~ threaded into the inner surface 11 o~ Che tube 10 prior to the ~ube being inserted into the common bore 49. The hang~ bolt 20 has a f irst threaded sec~ion 21, in threaded enq~g~ment with the inner ~urface 11. a gcipping section 23 to facilitate threading the ~irsc threaded seccion 21 into the tube 10, and ~ second threaded section 22. Ducing installation, th~ bolt ZO is threaded into one en~ of the ~ube 10 le~ving ~t le~st the second threaded sectio~ ~2 exposed bey~nd ~e ehd of the tube. Similarly, anothe~
hanger bolt ZS, having a first threaded ~ection 26, a ~ripping ~e~ion 2~, and ~ second thLeaded ~e~tion 27, is threaded in~o the inner sur~ace 11 a~ ~he op~osi~e end of the tu~e 10. ~lso, prior to the tube ~0 being inserted into the common bore 49, some mean~ i6 provided to co~st~ain ~he hanger bolts ZO and ~S against the pieces 50 and 55, respectivel~ . One preferred means h~s ~een a ca~
nut 30 th~eaded onto the second threaded sec~io~ 2Z of the hange~ bolt 20. The cap nut 30 has a head poction 31 having a mounting surface 33, and a threaded portion 32 extendin~ perpendicularly from the mounting surace 33.
The mounting surface 33 has an efec~ive diameter greater than the e~ective diameter o~ the com~on ~ore 4g so that the head por~ion cannot gass through ~he bore. The threaded portion 32 has an interior circumferen~ial surface 3~ with intefn~1 receiving threads 35 ~ormed in the surfa~e 34. The second threaded section ~Z of the bolt 20 is, thus. in th~eaded engagement with these inte~nal ~ecei~ing ~hreads when ~he cap nut ~0 is threaded onto ~he h~nge~ bolt 20. ~ny mean~ to tight~n thc cap nut onto the hanger bolt is acceptable, however, th~ p~efe~red method to date ha~ ~een the provi~ion o~ a screwdri~rer 610C 36 in the head portion ~1 of the cap nut ~0 to receive a screwdriver fo~ f~cilit~ting th~eading ~he ~ap nut 30 onto the hangel bol~ Z0.
During assem~ly, one end of the tu4e 10 is inserted into the co~on bore 49 u~til the mounting ~u~ace 33 of the cap nut 30 abuttingly engages the end outer surface 52 o~ the ~irst piece 50. ~n this configurati~n, ~he opposite end of the tube, and pac~icularly the second th~eaded section 27 of ~he h~nger bolt 2~, i8 nea~ ~he end outer surface 57 of the second piece 5S. A second ca~ nut 30 i~ then engaqed ~i~h the hanger bo~t 25 so that the second threaded section Z7 is thceaded into the receiving in~ernal thread~ 35 o~ the threaded poe~ion 3Z. This threaded enqagement is tightened until the mounting surface 33 of the h~ad portion 31 o~ the cap nut 30 is abuttingly engaged with the outer surface 57 of ~he second plece 55.
In chi~ pre~erred embodimen~, each cap nu~ 30 abutting the end outer surfaces 5Z and 57 ~an c,e ti~htened onto the hanger ~olts 20 ana 25 using a sclewdriver in the slot ~6. As ~he cap nuts are tightened, the tube 10 is pUt into increasing longitudinal ~ension. This longi~udinal tension holds the mounting sur~aces 33 of the cap nuts against the end ou~ec sureaces 5Z and 57, consequen~ly holding tlle first and second pieces S0 and 55 in compressed enSagement. The longitudinal ten~ion in ~he tube 10 holds the pieces together while permit~ing each ~z~
piece to ro~ate about ~he longitudinal a~is o~ ~he ~u~e ~elative to the tube and rela~ive to each other. The flexibility of the tube and the degree of tension put on i~ also allow the cube, and conse~uenrly ~he pieces, to ~ssume a contour ~hape. It i& unde~stood ~hat additional piece6, each hav~ng a bore, can be ~run~ on~o ~he tub~
between the f i~ and ~econd end piece6, and held in position by the longitudinal ~ension in the tube.
It is also understood that v~ria~ions on this preferred embodiment are pecmissible, including ~he repl~cement of t~e hanger bolt 20 a~ one e~d o~ t~e flexible tube ~ith ~ome ot~er re~training mean~ ~or ~teven~ing the tube from pulling through the common bore 4g. Suc~ restraining m~ans can compcise a ~top ~olded into the end of the tube. the stop having an effective diame~er larqer than the effective diameter of ~he ~ore 49. The hanger bo~t may ~lso ~e replaced by a co~ter pin in~erted throu~h a trans~erse bor~ cut in one end of the tube adjacent to the end outer sur~ace 52. In a ~urther variation on this embodiment, the ~ube 10 ~ay be longer than t~e e~fective length of the common bore 4g. ~uring ~sembly, the tub2 is stretched within t~e bore, a notch or a hole i6 cut in the tube adjacen~ to the end outer ~urfa~e SZ, and a hanger bolt and ~ap nut are inserted therein. ~he excess tube can be severed and discarded.
A beneficial feature of this invention is th~ this arCicle o~ knock-down furniture 5 and t~e contact joint assembly 18 herein descrihed aLe not ~omplicated and do not require special ~vols or procedure6 to assemble.
g Thus, the end~usec con6umec can easily as~emble an entiro article of ~noc~-down fu~nicure ln ~ 6ho~t pe~iod of time. Further, ~he contact joint a~embly in the prefe~red embodiment o~ the present invention allows adju~tment o~ the ten~ion i~ the tube 50 that as the tube strecches a~ter &everal u~es the r~lting slack in t~e tube C~tQ be elim~nated. Ano~he~ bene~it of ~e present embodiment is th~t the ar~icle of ~urnituce can be ~ust as easily disassembled.
~ he m~erial of the ~lexib~e tubin~ can be any material havîng high-~trength ~nd flexibi~ity characteris~ics. The t~be must have sufficient tensile str~ngth to wit~stand che ten~ion under whieh i~
opera~es . It must have ~uf~icient flexu~al strength ~o endu~e p~riodic f lexin~ ~$ the furnitur~ i5 opened and closed or subje~ So e~ernal loads. For this embodiment, the tubing must also ~e capable o~ receiving and re~aining threads. The ~lexible euhing c~n ~e a hi~h-stren~th ny~on tubing o~ the ~pe produce~ by The Polymet Co~por~tiPn under the ~ark ~ylaflow. For example, in a~licant's pre~erred work to da~e, ~he cube has an outer diame~er o~
1~4 in~h and an inner diamete~ o~ 1~8 inch. Each hanger holt is of a type commercially a~ailable at mosc hazdwace ~tores and is 1 1~2 inches long and has a diameter o 3~16 inch. ~lightly ~arger ~han the inne~ diameter of the ~lexible cube so that che hanger bolt can cut ~hceads into the tube when assembled. The hanger bolt i~ th~eaded into the tube so that about 1~2 inches of the second th~eaded go~tion i~ exposed beyond the tube. ~he cap nut i~ al60 comme~ciall~ availa~le and has a th~eaded por~ion 5/8 inches long with a~ outer diameter of 1/~ inch and an inne~ thread diame~ec o~ 3/16 inch to receive the ~/16 inch diameter ~hreads o~ the hanger bol~. The mounting sur~e o~ the head po~ion of ~he cap nut has a di~meter o~ 1~2 inch. thu6 the common bo~e in the first and second piece6 ~ust have a ~iamete~ b~tween 1~4 and 1~2 inch in o~der Co ~eceive,;the cap ~ut thr~aded ~ortlo~ wi~hout having the cae nu~ fall into the com~on bore.
In another embodi~en~ of the present invention, the first and second eieces ~0 and 55 each haYe~a bore 51 and 56, ~espec~ively, and are abutted a~ previou~1y described to form a common bo~e 49. ~ ~lexihl.e ~ube 70 has a hole or a rounded no~h 71 cut near one end of the tube and qxtending subs~antially through the tube ~o a teaI segment 72, as shown in FIG. ~ is under6tood ~hat ~hi6 not~h can be cut into the tu~e prio~ to or a~ter the tube '70 has been inserted into the commvn bo~e 49. ~n exsess lead portion 73 is extended f~om the notch 71 to the end of ~he tube 70. The tube is of su~ficient length ~o that the exce~s lead portion 73 extends beyond the common bore 4g when the ~emainder of ~he tube is fully within the common bore. ~ SCL~W a~sembly 60 is threaded i~to the interior circumferencial su~ace 75 9~ tne Cube 70 at the end oppo~ite the end with the notch 71. Th~ screw as~emb1y 60 comprises a typical sheet metal sc~e~ 61 extending through a washer 62. The washe~ 62 has an e~ective diameter greater than the e~fective diameter of the common bore ~9 to ~revent the 6crew assemb1y 60 from passing throu~h the common bore. The ~etal screw h~s a ~hreaded por~ion 65 that is threadad into ~he t~be.

~21~
The end of the Cube 10 havinq ~he no~ch 71 i~ extended Chrough the common bore ~9 until ehe w~sher 62 abuts the end outer surface 5~ of ~he f iCSt piece 50. In this po6ition, the notch 71 and ~ear segment 7~ will be slightly recessed within the ~ommon bore 4g, while the excess lead portion 73 wil~ extend beyond the end oute~
surface 57 of th~ second piece 55. ~he ~ead por~ion 73 i~
~ulled until the hollow tube 70 is taut. A ~econd screw assembly 60 is inse~ted through the noech 71 and ~hr~aded into the inner ~i~cum~eren~ia~ sucface 75 o~ the ~ube 70, as shown in FIG. 6. The lead portion 73 is held ~gainst Che end o~ter surace 57 while the scre~ assembly is inserted in orde~ to pcevent rotation o~ ~he ~ube 70 ~hile the s~ew assembly is th~eaded in~o the inner circumfecential su~face 75. The ~h~eaded po~ion 65 of the s~eet metal screw 61 is Chceadea inCo t~e tube un~il the w~sher ~2 abuts ~he end ou~ec surface 57 o~ the ~cond piece SS. The tea~ segment 72 and a portion of the excess lead portio~ i~ pinched het~een the washer 61 and the end ou~er sur~a~e 57. The exce~s lead por~ior3 73 is separa~ed rom the ~ube 70 at the tea~ segment 72 ~o that no piece of the tube projects beyond che washer 61 and the remainder o~ the tube 70 i8 contained within ~he commo~
bore 49. The ~crew assembly 60 in either end of the t~be is tightened to pl~ce the tube in longit~dinal ~ension.
At this ~oint, this second embodiment has functional features substantially similar ~o those ~reviously described in connection with the ei~S~ embodiment.
~ ach of che e~bodiments o~ the pLe~en~ invention herein described represent a new and useful means for Coupling tWO or mo~e pieCe8 in an artlcl~ of knook-down ~urniture. ~ach is inexpenslve and easy to undeL~and and assemhle by an end-u~er consume~. ~he components o~ the assembly, namely the ~lexible ~be. hangee bolts, cap nuts, oe, alterna~iYely, ~he ~heet metal screws and wa6he~s, ~e all commeccially a~ailable in most hardware ~tore~. !' While ~he inventions have been illustrated and described in de~ail in the drawings and fo~egolng description. the same is to be considered a~ illust~ative and not restrictive 1~ cha~acter, it bein~ understood that only ~he prefer~ed embodiments have been ~hown and describe~ and that all cha~ges and modifi~ations that come within the s~i~it o~ the in~ention are d~sired to be protected.

Claims (20)

1. An article of knock-down furniture that can be easily assembled by the end user, comprising:
a plurality of pieces formed to constitute said article of knock-down furniture when said pieces are in an assembled configuration;
said assembled configuration having at least one contact joint formed by a number of said pieces each having a correspondingly aligned bore therein;
means, including a flexible non-rigid member passing through said bores, for adjustably stringing together said pieces and for adjustably securing said pieces under compression in a manner to form said assembled configuration of said furniture; and wherein said flexible non-rigid member comprises a plastic tube having an interior engagement surface extending at least partially therethrough, said tube further having a length sufficiently short for said interior engagement surface to reside entirely within said aligned bores of said number of pieces when in said assembled configuration.

2. The article of knock-down furniture of claim 1, wherein said means for adjustably stringing together and securing said pieces is removable.

3. The article of knock-down furniture of claim 2, wherein said means further comprises:
a threaded fastener having a threaded portion and a head portion;
said threaded portion being in threaded engagement with said interior surface at one end of the flexible tube; and said head portion having an effective diameter larger than the effective diameter of said aligned bore such that the head portion cannot pass through said bore.

4. The article of knock-down furniture of claim 3, wherein said threaded fastener further comprises:
said head portion being separable from said threaded portion;
said head portion being in threaded engagement with said threaded portion and being so arranged to permit variation in the axial tension in said plastic tube when in the assembled configuration.

5. The article of knock-down furniture of claim 4, wherein said means further comprises:
an additional threaded fastener, having a threaded portion and a head portion, in threaded engagement with said interior surface at the other end of the flexible tube.

6. The article of knock-down furniture of claim 4, wherein said means further comprises:
a non-adjustable restraining element in fixed relationship with the other end of said flexible tube, said restraining element being configured so that said element cannot pass through said bore.

7. The article of knock-down furniture of claim 6, wherein said restraining element comprises a cotter pin passing through a transverse bore in one end of said flexible tube.

8. The article of knock-down furniture of claim 6, wherein said restraining element comprises a stop formed into one end of said flexible tube.

9. The article of knock-down furniture of claim 4, wherein:
said head portion engages said threaded portion at an engagement region, said engagement region residing entirely within said aligned bore of one of said number of pieces when in said assembled configuration.

10. An article of knock-down furniture that can be easily assembled by the end user, comprising:
a plurality of pieces formed to constitute said article of knock-down furniture when said pieces are in an assembled configuration;
said assembled configuration having at least one contact joint formed by a number of said pieces each having a correspondingly aligned bore therein;
means, including a flexible non-rigid member passing through said bores, for adjustably stringing together said pieces and for adjustably securing said pieces under compression in a manner to form said assembled configuration of said furniture; and wherein said flexible non-rigid member includes:
a flexible tube having;
a first end and a second end;
a notch through a portion of said tube situated near said first end and defining a lead portion between said notch and said first end;
a first interior engagement surface at said notch and extending at least partially therethrough; and said flexible tube further having a length measured from said notch to said second end adapted to allow said notch to reside entirely within said aligned bore of one of said number of pieces when in said assembled configuration while said lead portion extends beyond the end of said contact joint.

11. The article of knock-down furniture of claim 10, wherein:
said notch further defines a tear portion connecting said lead portion to the remainder of said tube so that said tube can be placed in tension on application of a pulling force to said lead portion, said tear portion being adapted to be severed to separate said lead portion from said tube on application of a separation force to said lead portion; and said means for adjustably stringing together and securing said pieces includes:
a first screw assembly adapted to be threaded into said first interior engagement surface, said first screw assembly having a head portion with an effective diameter larger than the effective diameter of said aligned bore such that said head portion cannot pass through said bore.

12. The article of knock-down furniture of claim 11, wherein:
said flexible tube includes a second interior engagement surface extending at least partially therethrough at said second end; and said means for adjustably stringing together and securing said pieces further includes:
a second screw assembly adapted to be threaded into said second interior engagement surface, said second screw assembly having a head portion with an effective diameter larger than the effective diameter of said aligned bore such that said head portion cannot pass through said bore.

13. The article of knock-down furniture of claim 11, wherein said means for adjustably stringing together and securing said pieces further includes:

a non-adjustable restraining element in fixed relationship with said first end of said flexible tube, said restraining element being configured so that said element cannot pass through said bore.

14. The article of knock-down furniture of claim 13, wherein said restraining element includes a stop formed into said second end of said flexible tube.

15. An assembly for coupling a plurality of pieces, comprising:
an aligned bore extending through each of said plurality of pieces, said plurality of pieces comprising at least a first end piece and a second end piece;
an axially stretchable tube made from an elastomeric material, said tube having an interior surface at least partially therethrough and passing through said aligned bore; and means for removably securing said stretchable tube to, and in axial tension between, each of said first and second end pieces, thereby holding each of said pieces in a fixed longitudinal relationship, while permitting relative rotation between each of said plurality of pieces.

16. The assembly of claim 15 wherein said means for removably securing said tube comprises:
threaded fastener means having a threaded portion and a head portion;
said head portion having an effective diameter larger than the effective diameter of said aligned bore such that the head portion cannot pass through said bore; and said threaded portion having a first threaded section, said first threaded section being engaged with the interior surface of one end of said tube wherein rotation of either portion of said fastener means will cause a change in the axial length of said tube.

17. The assembly of claim 16 wherein said threaded fastener means further comprises:
said threaded portion separable from said head portion;
the head portion having a bore with longitudinally extending receiving threads on the interior surface of said bore; and the threaded portion having a second threaded section extending beyond the end of said tube when the threaded portion is engaged therein, said second threaded section engaged with said receiving threads to removably secure the threaded portion to the head portion so that the engagement of the second threaded section and the receiving threads is sufficient to permit variation in the axial tension in the tube when the assembly is complete.

18. The assembly of claim 17 wherein said engagement of the second threaded section and the receiving threads is situated substantially within said aligned bore without extending beyond the outer surface of said end piece.

19. The assembly of claim 15 wherein said stretchable tube is made of nylon.

20. The assembly of claim 15 wherein the length of said tube can be increased by said securing means acting on said tube.