CA1075561A - Foldable free-standing tent, frame and subframe therefor - Google Patents

Abstract

"FOLDABLE FREE-STANDING TENT, FRAME AND SUBFRAME THEREFOR"
ABSTRACT OF THE DISCLOSURE
This invention relates to a collapsible tent structure com-prising a pair of improved subframes hingedly interconnected at their adjacent corners and cooperating with one another in the fully unfolded condition.
A fabric connects the lower edges of the subframes together to define a free-standing assembly.

Description

In my earlier Canadian Patent No. 981,143,1 disclose a tent, ~rame and subframe which, despite it~ many advantages over the prior art units for the sa~e purpose~ nevertheless had a few shortcomings. One of these was the design of the subframe, particularly in the area of the connector. The rib-forming strut sections all extended radially outward ~rom the connector and each was attached to the latter for pivotal movement about an axis spaced outwardly from the center thereof 50 as to leave room for the four strut sections to move into a side-by-side ~olded relation. UnfortunatelY, this same connector had to carry the stops on the periphery thereof that limited the fully unfolded position of the strut sections to an angle greater than 18~ and less than approximately 220.
In so doing, the size of the connector had to be made inordinately large so as to spread the axis of pivotal movement and stop far enough apart to eliminate undue s~ress on the parts thus connected. Looking at this problem another way, if the distance separating the pivot pin mounting the strut section and the stop on the periphery of the connector is only an inch or so with a strut section a yard long, a mechanical advantage of some 30:1 or so is acting to deform, bend or otherwise damage the parts. Now, while the tension exerted by the stretchable cord reaved around the free ends of the strut sections can easily be adjusted so as to not overload this connection, other forces cannot such as , for example, pressing against the inside wall of the tent which is a very co~mon occurrence when confined in a small area. By the same token, a small gain by way of an increased spacing between the pivot axis and associated stop results in a considerable reduction in the mechanical advantage responsible for the excessive loads to which the assembly is subjected. Obviously, doubling the space between the pivot pin and stop results in the mechanical advantage being reduced by over 50X; however, the important thing to remember is that this can be achieved by moving the stop away from the pin perhaps as little as an inch or even less.

~075561 To accomplish. the foregoing by increasing the.size. of the connector, however, creates more prob.lems than it solves. ~eight i:~ always ; a problem in a portable structure such as this and enlargi'ng the.size of the connectors substantially contrlbutes to an undesirable increase in this area. Even more important, however, is the attendant i:ncrease in bulk of the assembly in folded condition. These connectors all end up in side-by-side nested relation to one another as shown in Fig. 3 of my earlier patent and it is easy to i~agi:ne what effect increasing the size '.
of the connectors would have upon the overall bulk of the bundle thus formed.
The tent of my earlier patent had no floor so as to provide access to an underground installation through an open manhole covered thereby. The cover, while attached to the frame, contributed nothing by way of cooperating therewith to produce a free-standing structure as the frame alone provided the necessary structural support. Also, while the stretchable cords outlining the subframes were attached to the cover by enclosing same within hems stitched along the borders thereof, no con-nection was provided between the frame and fabric in the center of the walls and roof. This proved to be a disadvantage because, when the tent was collapsed, the fabric covering the subframes did not follow the connector inwardly so as to fold inside the strut sections.
It has now been found that these and other shortcomings of my earli.er tent can be eliminated by, first of all, mounting the sections of ; each strut in transversely-spaced side-by-side relation with their adjoint ends slightly overlapped. By so doing, the same size connector can be rearranged to provide over twice the space separating the axis of pivotal " movement and s-top means as was possible with my earlier desi.gn. By so rearranging the connector, the center thereof is left free to accept a line from the adjoi'nt fabric wall coveri`ng same that cooperates wlth said connector to pull the fa6ric and fold same witfiin t~e bundle of strut secti`ons as tfie su6frame 1~ collapsed.

~07556~

The tent of the present invention i.s desi.gned primarily for .
camping rather than a cover for th.e entryway into underground installations, therefore, it can and does i.nclude a floor whi'ch cooperates with the subframes supporting the side walls to defi:ne a stable free-standing ..
structure whi.ch i't would not be without the floor or some analogous connection between the bottom margins of th.e side walls. This floor, in fact the ground-engaging underside thereof, ends up as the outside cover for the tent in collapsed conditi.on. As such, i't keeps mos.t of the dirt on the outside where it can most easi:l~ be removed. Also, by mak;ng the floor of heavier stock than the walls;, i:-t offers substantial protection for the remainder of the assembly folded inside thereof.
Finally, to further reduce the strai'n on the connector when the subframe is unfolded, the strut sections, wfi.ile stlll rigid, are preferably made of springable plastic rods that wi'll bow slightly under load and thus relieve some of the stress on the pivot pins, stops and the like. As the~e s.trut sections bow outwardly, they stretch the fabric coveri.ng them taut and pres~ent a much neater loo~ing tent as well as one having a slightly increased volume.
Broadly stated, the invention i.s a tent frame comprising in combination: a pair of collapsible subframes effective in open angularly disposed position to define a framework having lower edges capable of .
supporting a wall covering when stood on said lower edges, each of said subframes i:ncluding three or more substantially rigid strut sections and a centrally-located hub-forming connector, said strut sections each being pivotally connected at one end to said connector for hinged movement from a folded position lying alongside one another on the same side of said con-nector i'nto an unfolded position radiating from the latter in angularly-spaced relation; fastener means hingedly connecti`ng saîd subframes together at points remote from said lower edges; and, sheet fabric means connecting said lower edges of the subframes together so as to limit the maximum separation therebetween when unfolded, said sheet means also cooperating - - \

1~75~
with the fastener means and with s~aid subframes in open position to define a free-s:tanding structure, and said sheet means further cooperating with said subframes in cQllapsed condition to envelop same and form a protective covering therefor.
Fig. 1 is a perspective ~i:e~ looki`ng down and to the right upon the front of the tent, portions of the near si`de wall havi`ng been broken away to reveal the interior construction, Fig. 2 is a perspective view like Fig. 1 and to the same scale Qf the frame alone;
Fig. 3 is a front elevation;
Fig. 4 is a side elevation to a sli:ghtly reduced scale;
Fig. 5 is a section to the same scale as Fig. 3 taken along line 5--5 of Fig. 4;
Fig. 6 is an enlarged fragmentary section taken alang line 6--6 of Fig. 4;
Fig. 7 is a fragmentary section to the same scale as Fig. 6 taken along line 7--7 of Fig. 4;
Fig. 8 is a fragmentary section to the same scale as Figs. 6 and 7 taken along line 8--8 of Fig. 3;
Fig. 9 i~ a fragmentary section to the same scale as Figs. 6-8 inclusive, taken along line 9--9 of Fig~ 3;
Fig. 10 is a perspective view showing the tent in fully folded condition as it would be seen from a vantage point above and to the left thereof;
Fig. 11 is a fragmentary view to a further enlarged scale showing the connector, ctop and strut section subassembly;
Fig. 12 is a fragmentary section taken along line 12--12 of Fig. 11 to the same scale as the latter;

107~56~ , Fig. 13 i5 a fragmentary secti~n. to the same scale as Figs. 11 and 12 taken along line 13--13 of Fi'9. 11;
Fig. 14 is a fragmentary detail to the same scale as Fi'gs. 11-139 inclusive., showing the details of the corner subassembly where the floor S joins the side wall and end wall;
Fig. 15 is a fragmentary s~cti.on ta~en along line 15--15 of Fi.g. 14;
Fig~ 16 is an exploded view to the same scale as Fi'gs. 11-15 showing the end subassembly of Fig. '14;
Fig. 17 is a fragmentary view to the same scale as the fi5ures immediately preceding same sho~n'ng the hinged connection between the two subframes; and, Fig. 18 is a fragmentary corner detail of the same corner depicted i.n Fig. 14 except that it s~ows only the fabric cover without the associated hardware in perspective.
Referring next to the d~awings for a detailed description of the present invention and, initi.ally, to Figs. 1 - 5, inclusive, for this purpose, re~erence numeral 10 has been used to broadly designate the - ground tent in its entirety while numeral 12 similarly designates the frame thereof and numeral 14 the cover or skin. Frame 12 is further broken down into a pair of substantially identical subframes that have each been referred to in a general way by numeral 16.
In the particular fo m shown, the tent 10 is of traditional shape having a pair of generally rectangular side walls 18 joined together along their com~on upper margin 20. The walls slope downwardly and outwardly in divergent relati.on from the ridge defined by upper margin 20.
The ground i5 covered ~y a floor ~2 forming an integral part of the cover 12. As illustrated, t~s floor has an upstanding marginal cuff 24 : h~ich adj9îns t~e side walls and the trlangular end walls Z6. Cuff 24 ; 30 als-o provides poc~ets 28 along opposlte sl~des t~ereof t~at recel've and reta~n t~e lower marglnal edges 3~ of ~h~ ~rame su~assemblles'16 and prevents : !
: - 6 -them from spreading apart. The caver 12 thus~ coop~rates with the frame 14 in assembled relation to produce a stable free-standing structure that neither is capable of producing alone.
I`n Fias. 1 and 3 it can ~e seen that the front end wall 26F is divided in half by a vertical zipper fastener 32 that joins a horizontal zipper fastener 34 along the top of the cuff 24. Opening these two zippers frees a pair of flaps that provide both venti`lation and access in the usual manner. As illustrated, a net wall 36 simi1arly zippered is placed behind front wall 26F to Reep out insects while insuring the free circulation of air.
Rear wall 26 does not open up the same way as the front wall 26F
but, instead, is provided with a net-covered window 38 as shown in Figs. 1 and 5. This window is covered by a zippered flap 40. While features such as the construction of these end walls is optional and well within the skill of an ordinary artisan, the triangularly-shaped tube defined by the side walls and floor cooperates in a unique way with the frame 14 to produce a unitary collapsible assembly with no loose parts that can be set up or taken down without the use of any tools, stakes and the like by a completely unskilled person in literally a matter of a few seconds.
The manner in which this desirable end is achieved will now be set forth in detail with specific reference first of all to Figs. 2, 11, 12 and 13 for a description of the improved subframe 16.
Each subframe has a hub-forming connector 42 to which is pivotally attached two pairs of jointed struts 44 disposed in right-angular

2~ intersecting relation to one another. The sections of each strut have their adjacent ends 46 arranged in side-by-side transversely-offset slightly overlapped relation a$ revealed most clearly in Fig. 11. These ends thus offset and overlapped lie on opposite si`des of the center 48 of the colmector ~ut are mounted, in the partîcular fonm s~own, for independent pivotal mo~ement about a common axis 50 passing t~roug~ the latter. rt is, of course, po~si~le ~o mount eac~ stru~ section for pivotal movement about a separate axi.s a~ wel ~ 7O ~. ~ ~ dQe5 not pass through the.center of the connector. In fact, as pre.Yiousl~ noted, the greater th~ spacing 6etween.
axis 50 and the edge ~2 of the connector tfiat defines th~ stop which limi.ts the movem~nt of each section into fully-extended position, the fietter it is for loweri.ng the stress placed upon the 5ubassem61y 6y a strut section ~f a .- given length. Thus, by adopti.ng this offset and overlapped confîguration in preference to the design of my earlier patent where the ends of the strut sections were spaced apart on oppo5îte sides of the center of the connector ~.ut in longitudinal al.ignment wn~th one another, I am able to ; 10 easily double the distance separati.. ng axis 50 from the stop-defining edge 52 of the connector and thereby halve the stress on the latter element without increasing its size. Furthermore, one can greatly reduce. the overall size o~ connector 50 and still accomplish a significant reduction in stress through use of the improved subframe.
Now, the marginal edge 52 of connector 42 cooperates with the pivot axis 5a of the strut sections 44 in the same manner as my earlier patent to limit the fully unfolded relation between said sections of each foldable strut to one in which they bear an angular relationship to one another that exceeds 180 yet is less than approximately 220. This so-called "over center" condltion is re.leasably maintained by a stretchable . c-)rd 54 connected to the remote ends 56 of each strut section. In the collapsed or folded condition illustrated in Fig. 10, the strut sections lie in side-by-side more or less parallel relation wnth both connectors 42 a-, longside one another at the same end as shown.
2~ In Fig. 2, it will be noted that ~egment 54C of cord 54 is shared by the two subframes 16 and extends along the ridge defined by upper marginal edge 20. As such, t~is. segment permanently joins these . two subframe~ together to produce the tent frame 12. The frame thus fnrmed îs further permanently attached to the cover or skin 14 which ; 30 cooperates therewith to produce a unitarr assemfil~ to which detalled reA~erence ~ill be made presentl~. j ' I

. 8 ~075561 ln Fig5. 5-9, 11, 12 and 13 it can be seen that the strut sections include springable midsectionsi 58 fabricate.d from plastic rod~, the opposîte ends of which are permanently attached by means of pi'n~ 6a into sockets 62 provided in the fi'tti.ngs 64 and 66 that are located on the adjacent and remote ends thereof, respectively. Connector 42 has a hole 68 in the center thereof through which passes a short lanyard 70 that i's sewn as otherwise attached to a patch 72 ~Fi`g. 12~ similarly attached to the side wall 18 of the. tent S~lh 12. Accordingly, a pull upon lanyard 7C will draw the sl.de wall up ~nug against the connector 42 and thus return the strut sections. back over center into the folded condition of Fig. 10, all the while insuring that the side wall will be inside the strut sections in their bundled conditi'on. In my earlier tent, I showed no such connection and the struts could be folded leaving the fabric covering same on the outside.
Next, with reference to Fig. 5, it will be seen that the bendable nature of the strut sections i.s such that they will assume an outwardly bowed configuration when fully unfolded and held under stress by the tensioned cord 54 connected from the remote end of one strut section to the next. As thus bowed, the subframes serve to remoYe all slack from the side wall fabric thereby keeping it taut and free of the flapping noise which is so annoying wben the wind blows against the loose walls of the ordinary tent. This same bowable subframe makes it far easier to adjust cord 54 which can be pulled taut enough to establish the bowed condition illustrated knowing that the strut sections will yield and not break the cord as they move between their folded and unfolded positions relative to connector 42.
Now, the fittings 66 on the remote ends of the strut sections differ materially from those (64~ on t~e adjacent ends pivotally attached to connector 42 and they are most cle.arly revealed in Figs. 14-17 to which detailed re.f~rence ~ill now.6e made. A somewha~ shallower socket 62M is provided f'or plast~c mîdsecti'on 58 and tfie la~ter is held in place by .

crimping.the end of fitti.ng 66 aC shown at 74 rather than using a pin connector.
The other end of the ~itting opposite that contai:ning socket 62M
is longitudinally slotted as shown at 76. At the base of the slot is a relatively narrower keyway 78 of a widtfi adapted to pass the cord 54 while retaining ball 80 swaged on the end of said cord releasably locked within the slot în the manner clearly shown i`n Fig. 1~. Both terminal ends of the cord 54 are proYi`ded witfi balls 8~ and are thus detachably fastened with.in tfie fitting 66 on th~ remote end 56 of each. strut section.
In ~y previous patented construction, I use. a single long length of cord to connect all the strut ends of each individual subframe together, however, the instant construction wherein separate segments of cord 54 of a length selected to span the gap separating one unfolded strut section from the next is preferable. For one reason, in case of damage to one cord segment, i:t can be replaced quite easily without having to unthread and rethread the cord through the cord-retaining sleeves 82 that are provided at the corners between the side and end walls as well as between the walls and the floor.
Once the terminal ends of the cord segments are positioned in the keyslots 78 and the balls 80 retalned therebehind, D-rings 84 are passed onto one of the fingers 86 cooperating with slot 76 to.define a bifurcated end on fitting 66. This D-ring blocks the mouth of keyslot 78 in the manner shown most clearly in Fig. 14 and prevents tbe cord end from backing out of the latter. A large metal O-ring 88 is then inserted into slot 76 on top af the D-ring as shown in Figs. 14 and 17. Straps 90 in the four corners of the tent floor tie onto these rings 88 and thus provi.de a releasable connection 6etween the subframes and fabric cover at floor level. A slmflar strap at the front and rear corners of the ri.dge CFig. 171 ties onto O-rings 88, a sl~ngle one of which is ~hared b~ t~e corresponding strut sections of th~ two sl~de wall-supportlng ~' I
-lo- !

107556~ 1 subframes and used to connect ~ame together. A retaining pin.92 screwed into aligned internally-threaded openi'ngs 94 in the fingers 86 of the bifurcated fi.tting end bridges the slot 76 therein and retains the O-ring, D-ring and cord ends in assemhled relation. D-ring 84 can, of course, be opened up and removed to release t~e balls from the keyslots in case a cord needs to be replaced wlthout havi`ng to untie the O-ring from the corner straps.
Next, referring bri'efly to Figs. 6-9, 14, 17 and 18 i`t will be seen that cord-retaining sleeves:82 comprlse a single widtK of fabric folded over upon itself to form a tunnel, the margi'nal edges of which are then hemmed while, at the same ti'me, sewing the sleeve thus formed to the fabric of the tent. These sleeves extend along all corners formed between adjacent walls and these walls and the floor so as to shîeld the cord from wear and damage. They also terminate short of the corners when adjoini.ng side and end walls meet the floor as well as where the side walls adjoin one another along the ridge 20 to provide room for connecting the O-rings to the straps.
Finally, in connection with Figs. 1 - 5 and 10, it will become apparent that a pull on cords 70 from i.nside the tent will effect an instant folding of the subframes and a total collapse of the tent. The knots 94 in the ends of lanyard 7~ insure the fact that the side walls 18 w;ll fold into the bundle of folded strut sections as they define stops preventing withdrawal of the lanyard from central opening 68 in the ' connector. Obviously, as the subframes fold, the connectors 42 will drop down onto the floor and lie closely adjacent one another quite near the center thereof. Then, in folding the strut sections into bundled relation, the floor 22. of necessity ends up on the outside of the package thus formed so that all the fram~ members, walls:, cord and hard~are end up fully protected i'nside thereof. In addition, that portîon of the floor, namel~ the underside thereof that lay on the ground, ends up still on the outside of t~e package wfiere lt makes little. dlfference w~ether it is soiled or not. Furthenmore, t~e floor Is prefera61y made of stouter 1075561 1 ~
stock than the walls which further i.nsures, that the elements enve.loped there4y wfll.not be damaged during storage and handling of the tent in c~llapsed ccnditicn.

Claims (3)

What is claimed is:

1. A tent frame comprising in combination: a pair of collapsible subframes effective in open angularly disposed position to define a framework having lower edges capable of supporting a wall covering when stood on said lower edges, each of said subframes including three or more substantially rigid strut sections and a centrally-located hub-forming connector, said strut sections each being pivotally connected at one end to said connector for hinged movement from a folded position lying alongside one another on the same side of said connector into an unfolded position radiating from the latter in angularly-spaced relation; fastener means hingedly connecting said subframes together at points: remote from said lower edges; and, sheet fabric means connecting said lower edges of the subframes together so as to limit the maximum separation therebetween when unfolded, said sheet means also cooperating with the fastener means and with said subframes in open position to define a free-standing structure, and said sheet means further cooperating with said subframes in collapsed condition to envelop same and form a protective covering therefor.

2. The combination as set forth in claim 1 in which: the subframes fold inwardly toward one another.

3. The combination as set forth in claim 1 in which: the perpendicular distance from the connector to said lower edge of the same subframe is less than half the width of the sheet means measured between said lower edges.