A HUB AND STRUT-ENDCAP ASSEMBLY FOR A TENT FRAME

Abstract: This invention relates to a hub and strut-end assembly for the roof of a tent frame comprising two hub portions (20B,20L) fitted together in stacked relation to define therebetween a set of four sockets, each of which has a channel-shaped entryway adapted to receive a strut sleeve 26 projecting from a ball 24 on the inner end of one of the strut endcaps (14) and to permit limited side-to-side movement therein when in extended position as well as movement between its extended position and a folded position wherein the strut (18) connected thereto lies in nested essentially parallel relation to the other struts of the frame. Each entryway in the hub has its opposite walls (34,36) flared so that adjacent pairs of strut-­ endcaps retained in their respective entryway, can move from an extended right-angular relation to one another into an acute-angular relation thus cooperating with a like pair of sockets on the other side of the hub to enable the struts mounted therein to self-adjust and move from an essentially radial position from which a square wall or roof structure can be formed into non-radial relationship adapted for the formation of four-sided figures with at least two unequal side.

Description: This invention relates to a hub and strut-endcap assembly for a tent frame. In particular, the invention concerns a tent frame hub assembly of the type which, when made up in the form of a polygonal ring containing four or more hingedly interconnected strut end-receiving socket subassemblies, produces a self-adjusting structure that can be used to form multi-sided walls having sides of any desired length including all of them equal. Usually the struts used to connect the hub at the center with the corners of the tent frame are relatively thin and bendable to the extent that even though strut-receiving endcaps in the hub open out radially when in unfolded or extended position, the struts themselves can bend to th extent necessary to form a rectangular or trapezoidal wall structure. As the tubular plastic struts get bigger, say 0.75 inch (1.9 cms) outside diameter and larger, their walls become thicker and they will no longer bend to any significant degree, i.e. more than a few inches in a length of several feet. According to the present invention there is provided a hub and strut-endcap assembly for a tent which comprises a hub member shaped to provide four ball-­ receiving sockets arranged in equiangularly-spaced relation around the center thereof with each such socket adapted to receive and retain a ball for pivotal movement therein, said hub member including side-opening channel-forming entryways leading into each socket, said entryways each having divergent sidewalls bordering a pair of intersecting seats at the base thereof bearing an acute angular relation to one another, one of said pair of seats extending radially outward from its ball-receiving socket while the other end of said paired seats is skewed with respect to said radially-extending one, and adjacent pairs of said entryways having their radial seats or their skewed seats adjacent another, and four strut-­ endcap elements each having a ball on the inner end thereof and a sleeve projecting outwardly from said ball for receiving the inner end of a tent frame strut, said ball when seated in a said ball-receiving socket in the hub being shaped and adapted to align the sleeve extending therefrom for limited side-to-­ side movement between a first position seated in the radially-extending seat of the entryway and a second position seated in the skewed seat thereof, said hub member and strut-endcap elements cooperating with one another in assembled relation with the sleeves seated in their first positions to define an assembly specifically adapted to the formation of a square frame, and said member and elements cooperating with said sleeves seated in their second positions to define a four-sided polygonal frame having at least two unequal sides. The invention will now be particularly described by way of example, with̅̅reference to the accompanying drawings in which: Figure 1 is a fragmentary top plan view of a hub and strut-endcap assembly according to the invention showing in full lines the struts and their endcaps diagonally-aligned in their radially-extending positions in which adjacent pairs thereof are in right-angular relation to one another as well as the phantom line position in which the struts in opposite pairs lie in either non-radial acute or obtuse angular relation; Figure 2 is a fragmentary top plan view to a greatly enlarged scale, portions of which have been broken away; Figure 3 is a fragmentary side elevation to the same scale as Figure 3; and Figure 4 is a diametrical section taken along line 4-4 of Figure 2. As shown in the drawings, by way of example, a hub and strut endcap assembly 10 comprises a hub 12 and four identical endcaps 14 mounted for limited side-to-side movement when in extended or unfolded position as indicated by the full and phantom line representations of Figures 1 and 2. The ball-and-socket connection 16 (see Figure 4) also allows the endcaps and the struts 18 associated therewith to be folded into nested essentially parallel relation as seen on the left hand side of Figure 3. In Figures 2, 3 and 4, the hub 12 will be seen to comprise a two-part subassembly consisting of a base 20B covered by a lid element 20L which when bolted or otherwise fastened together define sockets 22 which retain therein the balls 24 on the inner ends of the endcaps 14 for the limited relative movement that will be described below. The balls 24, which comprise about three-quarters of a full sphere, merge through their truncated side with the tubular socket-forming sleeves 26 that receive the strut end as shown. The struts are joined to the endcaps using a suitable adhesive. In the particular form shown, the base and lid of the hub are detachably fastened together by four bolts 28 which pass through the areas between the sockets. The central opening 30 in the hub serves to receive a cord (not shown) by means of which the skin of the tent can be attached at its center to the frame therefor and thus be caused to fold inside the nested struts when the tent is stowed. In Figure 2 it can be seen that adjacent pairs of entryways 32A and 32B are the same shape but pairs A and B are mirror images of one another. Each of the entryways has an abutment-forming sidewall thereof 34 which lies in spaced parallel relation to a radial line emanating from the center of central opening 30. The extent of the lateral offset is the radius of the outside diameter of the tubular sleeve 26. Thus, as seen in full lines in Figure 1, when all four of the strut endcaps are positioned such that their socket-­ forming sleeves 26 abut up against their respective sidewalls 34, all four of the struts 18 will be extending out radially from the hub and bear a 90° angular relation to one another. However, two abutment-forming walls 34 are positioned to engage the anti-clockwise facing side of the sleeves 26 positioned in each of the entryways 32A whereas, the walls 34 in each of the entryways 34B engage the clockwise facing side of the sleeves 26 as seen from above. Nevertheless, if all four struts are the same length, as is usually the case in tent construction, then with the outer or remote ends thereof connected together by a cable, the resulting panel will be square. Obviously, by varying the length of the struts they can be assembled to form parallelograms, both irregular and regular trapezoids, the latter having some application in tent construction. Each of the entryways 32 also has a second abutment-­ forming wall 36 arranged in opposed divergent relation to the first wall 34. This arrangement, of course, places a wall 36 of adjacent entryways of the A pair and B pair next to one another as seen most clearly in Figure 2, so that entryway 32A' is a mirror image of the next adjacent entryway 32B', and 32A' ' is a mirror image of 32B' '. It is the walls 36 which form the abutments for the sleeves 26 when the sleeves are disposed to define the other than square wall and roof structures. In Figures 2 and 3, it will be seen that each of the four entryways contains a ridge 38 in the base thereof defined by the intersection of the divergent generally cylindrical seats 40 and 42 which merge into upstanding abutment-forming walls 34 and 36, respectfully. Seat 40 is the radially-extending one while the axis of seat 42 is skewed a few degrees to one side of the other of the axis of seat 40. In use, the sleeves 26 will rest in one or the other of the seats 40 and 42 abutting their respective abutment-­ forming walls 34 or 36. This happens because the hub itself is free to rotate clockwise or counterclockwise when the remote ends of the struts are tied together by cables (not shown). Thus, assuming that the abutment-forming wall 36 and its seat 42 diverges at an angle of 10° from its companion wall 34 and seat 40, then, whenever the strut pattern is such that the inclined angle between adjacent struts is less than 100° and over 80°, the strut-endcap sleeves will all likely lie seated in the radially-extending seats 40 abutting walls 34. Conversely, if the strut pattern is one in which the included angle therebetween is more than 100° and less than 80°, then the reverse is likely to take place and the hub will automatically rotate into a position in which the strut-endcap sleeves all lie in sets 42 resting up against wall 36. Thus regardless of the inclination of the struts relative to one another in the frame within the preset limits that accommodate some bending, say 10° or so, the strut-endcap sleeves in which they are seated will occupy one seated position or the other and never occupy an unstable intermediate position therebetween. Moreover, although a 10° flair will mathematically accommodate a ratio of side lengths approaching 1.5:1, the struts are not rigid and can easily bend a few degrees one way or another over their length of several feet. Therefore, a 10° divergence between abutment-forming walls 34 and 36 is entirely adequate for all but the most extreme situations. This provides a strut angle divergence totalling 20° without bending and probably at least 30° with it. Seats 44 in the lid-forming section 24 of the hub receive the sleeves 26 of the strut-endcaps when they, together with their struts, are in the folded or nested position (see the lefthand strut-endcap of Figure 3). While it is not critical, these seats have been shown with their axes parallel to the axis of central opening 30.

Claims: 1. A hub and strut-endcap assembly for a tent which is characterised by a hub member (12) shaped to provide four ball-receiving sockets (22) arranged in equiangularly-spaced relation around the center thereof with each such socket adapted to receive and retain a ball for pivotal movement therein, said hub member including side-opening channel-forming entryways leading into each socket, said entryways each having divergent sidewalls (34,36) bordering a pair of intersecting seats (40,42) at the base thereof bearing an acute angular relation to one another, one (40) of said pair of seats extending radially outward from its ball-receiving socket while the other (42) of said paired seats is skewed with respect to said radially-extending one, and adjacent pairs of said entryways having their radial seats or their skewed seats adjacent one another, and four strut-endcap elements (14) each having a ball (24) on the inner end thereof and a sleeve (26) projecting outwardly from said ball for receiving the inner end of a tent frame strut (18), said ball when seated in a said ball-­ receiving socket (22) in the hub being shaped and adapted to align the sleeve extending therefrom for limited side-to-side movement between a first position seated in the radially-extending seat (40) of the entryway and a second position seated in the skewed seat (42) thereof, said hub member (12) and strut-­ endcap elements (14) cooperating with one another in assembled relation with the sleeves seated in their first positions to define an assembly specifically adapted to the formation of a square frame, and said member and elements cooperating with said sleeves seated in their second positions to define a four-­ sided polygonal frame having at least two unequal sides. 2. A hub and strut-endcap assembly according to claim 1 characterised in that the paired seats are cylindrically concave and intersect to define a ridge (38) therebetween effective to cam the sleeve engaging therewith into one of its alternative positions when the remote strut ends are interconnected to form a frame. 3. A hub and strut-endcap assembly according to claim 1 or claim 2 characterised in that the sidewalls (34,36) of the entryways define fixed abutments effective to limit the side-to-side movement of the endcap sleeves. 4. A hub and strut-endcap assembly according to any preceding claim characterised in that the hub member comprises a base (20B) and a lid-forming element (20b) cooperating with one another when fastened together in stacked relation to define the ball-receiving sockets and flared entryways. 5. A hub and strut-endcap assembly according to any preceding claim characterised in that the hub member (12) includes third set of seats (44) on the opposite side of the sockets from the paired seats of the entryway, said third set of seats being positioned and adapted to abut the endcap sleeves (26) and maintain them in a position in which the axes thereof are essentially parallel to one another. 6. A hub and strut-endcap assembly according to any preceding claim characterised in that the hub member (12) has a central opening (30) therethrough for receiving fastening means for attaching the hub member to a tent frame skin. 7. A hub and strut-endcap assembly according to claim 2 characterised in that the paired seats of the entryways intersect at an angle no greater than 15°. 8. A hub and strut-endcap assembly according to claim 3 characterised in that the sidewalls of the entryway diverge at an angle no greater than 15°. 9. A hub and strut-endcap assembly according to claim 7 characterised in that the paired seats of the entryways intersect at an angle of 10°. 10. A hub and strut-endcap assembly according to claim 8 characterised in that one sidewall of each entryway lies in parallel relation to a radial line extending from the center of the hub member spaced to one side thereof a distance equal to the outside radius of the sleeve.

Inventors: BEAVERS, ALLAN E.
Applicants: T.A. PELSUE COMPANY
Application year: 1986
Main classification: E04B1
IPC codes: E04B1, E04H15, F16C11, F16B7