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DETAILED DESCRIPTION OF THE INVENTION
In the particularly advantageous embodiment of the invention illustrated, tent frame 1 comprises four legs each comprising a lower section 2 and an upper section 3, the two sections being pivotally connected by a pivot connector 4 and the upper section being pivoted to the upper clevis member of a clevis assembly 5. Leg sections 2 and 3 are hollow extrusions of suitable polymeric material, typically polyvinyl chloride. Pivot connectors 4 are also of polymeric material and are advantageously formed by injection molding from glass fiber-reinforced polyester composition.The upper and lower leg sections are identical and, as seen in Fig. 3, have transverse cross sections which are in the form of an elongated rectangle having longer sides 6 and shorter sides 7. Inwardly projecting flanges 8, projecting from the longer sides and spaced apart equally from the center of the rectangle, are provided. Throughout its length, each leg section has a reinforcing insert 9 having a transverse cross section in the form of a right angle cross, the edges of the inserts being engaged respectively in the junctures between of flanges 8 with side walls of the rectangular leg sections.
Lower leg sections 2 are disposed with the long sides of their rectangular cross sections directed inwardly of the tent so that these sections are relatively stiff against forces directed inwardly from the outside of the tent frame. Upper leg sections 3 are disposed with the longer sides of their rectangular cross sections at right angles to the long sides of the rectangles of the cross sections of the lower leg sections so that the upper leg sections can more readily bend to follow the curvature necessary to lead to the upper clevis member of the clevis assembly 5.
Advantageously, clevis assembly 5 comprises an upper clevis member 10, a lower clevis member 11 identical to member 10, and a center post 12. Each clevis member comprises a main body 13 having a central through opening 14 and a downwardly opening generally cup-shaped recess 15. Spaced clevis flanges 16 project radially outwardly from main body 13. At the bottom of the main body, reinforcing flanges 17 interconnect the adjacent flanges 16, as seen in Fig. 4.
As best seen in Fig. 5., center post 12 has a main body 18 of larger diameter, an upper end 19 of smaller diameter joining body 18 in upwardly directed shoulder 20, and a smaller diameter lower portion 21 which joins main body 18 at downwardly facing shoulder 22 and is threaded at its lower end. Lower portion 21 extends downwardly through the central opening of lower clevis member 11 and is secured to that member by the combination of upper washer 23, lower washer 24 and nut 25, as seen in Fig. 5. Seated on upper shoulder 20 is a stop member 26 dimensioned and shaped to fit slidably within the downwardly opening recess 15 of the upper clevis member.
At a point intermediate its length, each upper leg section 3 is provided with a pivot member 27, Figs. 8 and 9, and radial brace members 28 each have one end pivoted to one of members 27 and the other end pivoted between one set of flanges 16 of lower clevis member 11. The positions of members 27 and the length of members 28 are such that when the tent is erected as seen in Fig. 1 lower clevis member 11 is forced upwardly, bringing stop member 26 fully into the recess 15 so that member 26 is stopped by clevis member 10 with portion 19 of center post 12 received in through bore 14 of the upper clevis member.
As seen in Figs. 6 and 7, pivot connectors 4 are of generally U-shaped transverse cross section, side wall portions 30 being spaced apart by a smaller distance than side wall portions 31 so that the right angle displacement between leg portions 2 and 3 can be accommodated in the manner shown. As seen in Fig.7, the bottom wall 32 has a first portion 33 and a second portion 34 and these portions are displaced from the pivotal axes of leg members 2 and 3 by distances such that taking into consideration the 90° displacement between the leg portions, the leg portions are freely pivotable between the positions shown in Figs. 1 and 2. Advantageously, an upstanding rib 35 is provided at the free end of portion 33 and a rib 36 is provided at the free end of portion 34, the heights of these ribs being such that, with parts positioned as seen in Fig. 1, the end portions of the leg portions engage the respective ribs in the manner seen in Fig. 7. A reinforcing rib 37 is advantageously provided at the juncture between portions 33 and 34, as seen in Fig. 7.
Members 27 are identical and are advantageously cut from extruded lengths having the cross-sectional configuration seen in Fig.8 . Each member 27 has a base portion 40 with a through bore 41 which is rectangular transverse cross section and dimensioned to slidably accommodate upper leg portion 3. Members 27 have flanges 42 which are parallel and spaced apart by a distance adequate to freely accommodate one end portion of one of the brace members 28.
Leg portions 2 and 3 are pivoted to members 4 by pivot pins 43 in any suitable manner. Members 27 are fixed to leg portions 3 by pins 44. Brace members 28 are pivoted to flanges 42 by pins 45. The upper ends of leg portions 3 are pivoted to flanges 16 of upper clevis member 10, as by pivot pins 46. The ends of brace members 28 are likewise pivoted to lower clevis member 11 by pivot pins 47, Fig. 5.
It will be apparent that various changes and modifications can be made without departing from the scope of the invention as defined in the claims. Thus flanges 8, Fig. 3, can be replaced by partitions 8', Fig. 3A and reinforcing extrusion 9, Fig. 3, can be replaced by a filling of polymeric foam 9', Fig. 3A.
