Abstract:
A cam style hub and strut system for use in single panel fabric, cloth, or plastic units, or structures with an unlimited number of wall and/or roof panels. The purpose of the cam style hub is to compensate for certain fabric characteristics and to allow easier setup of structures containing flexible or rigid support struts connected to a central hub by lessening the distance of the diametrically opposing struts during assembly, and applying the force necessary to engage the self-supporting structure by engaging the cam, increasing the distance between the ends of the opposing struts. The amount the distance is increased can be dictated by materials used and the size of the panel. The hub may contain an optional “locking” feature activated when the hub cam is engaged for convenience and safety reasons. The principle can be used with any number of struts greater than one.

Description:
CROSS REFERENCES TO CO-PENDING APPLICATIONS 
     None. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is for a support system, and more particularly, pertains to a cam style hub and strut system for use in portable and semi-permanent structures. The present invention can be used in any number of structures, including but not limited to, portable or semi-permanent structures, such as ice fishing houses, movie screens, road crew signs, boat covers, tents, medical tents, hunting blinds, photography blinds, portable garages, and the like. 
     2. Description of the Prior Art 
     Portable or semi-permanent structures are popular and practical for many of the aforementioned applications. The shortcomings of the current art device centrally hubbed units lie in the impracticality of utilizing the proper amount of extra diagonal length between the rod or strut ends and the distance between corners of a panel. The diagonal distance between opposing strut ends must be sufficiently greater than the corresponding corner-to-corner measurement of the panel in order to hold the panel in place once the hub is forced through the center. When the struts used are of optimal length, the unit becomes very difficult to set up, and damage to the hub system or structure itself frequently occurs. Couple this with the fact that many optimal structural fabrics stretch and shrink when contacted with environmental conditions to which they are commonly exposed, for example, rain, high humidity, heat, sunlight, and the like, the optimal system then is one that can be adjustable. In systems utilizing fabrics prone to stretching or shrinking, the unit may be built so that the cam need only be engaged in conditions in which the fabric is found to be affected. This system couples ease of setup with the cam disengaged and application of the proper amount of pressure on the panel to hold the system in a fixed position with the cam engaged, utilizing either flexible or rigid struts depending upon the properties of the material used in the panel and the size of the panel. 
     SUMMARY OF THE INVENTION 
     The present invention incorporates a cam style hub and strut system with offset pivot points in the hub that when turned moves the opposing struts to a lineal orientation furthering the distance between the strut ends. This allows ease of setup partnered with the ability to apply a greater amount of diagonal force upon the panel in which they are installed, creating panels used in structures that were formerly prone to failure caused by (1) the forces exerted in erection, (2) changes in environmental conditions, (3) excessive wind or wind flap, specifically in wildlife concealment applications (wind flap equates to failure), (4) injury from sudden accidental collapse, and (5) inability to erect. The cam style hub also eliminates the need for excessive panel construction costs associated with current techniques incorporating elastic perimeters, no-stretch perimeters, spring-loaded strut end caps, and the use of various sizes of struts needed to match panel material weights and stretch properties. The framework of the cam need not go past 180 degrees and may incorporate a locking mechanism, if desired. The diagonal length of the struts is greater than the diagonal of the panel. The locking mechanism makes it possible to use same length struts if desired, meaning struts will not bow and the structure will stay up. 
     According to one embodiment of the present invention, there is provided a cam style hub and strut system, including a centrally located rotatable hub having a plurality of positionable struts extending outwardly therefrom to engage the outer regions of a flexible panel of cloth, tent material, canvas, sheet plastic or the like. 
     One significant aspect and feature of the present invention is a cam style hub and strut system having a centrally located rotatable hub which operates two or more struts outwardly. The cam style hub and strut system includes sockets which accommodate the ball ends of the outwardly extendable struts. The cam style hub and strut system incorporates over-the-center locks. 
     Another significant aspect and feature of the present invention is a cam style hub and strut system incorporating capture detents to lock the struts in the extended position. 
     Yet another significant aspect and feature of the present invention is a cam style hub and strut system having accommodational maneuvering channels, truncated slots and capture detents in which the struts can be positioned, maneuvered and locked or collapsed. 
     A further significant aspect and feature of the present invention is a cam style hub and strut system in which the struts are collapsible when not in use. 
     Having thus described one or more embodiments of the present invention, it is the principal objective hereof to provide a cam style hub and strut system. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects of the present invention and many of the attendant advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which like reference numerals designate like parts throughout the figures thereof and wherein: 
     FIG. 1 illustrates a cam style hub and strut system, the present invention, engaging a portable or semi-permanent panel; 
     FIG. 2 illustrates an isometric view of the hub and the inboard ends of the struts; 
     FIG. 3 illustrates a perspective and inverted bottom view of the hub; 
     FIG. 4 illustrates an isometric view of the capture plate with the actuator handle rotated at an angle with respect to the capture plate to reveal the inwardly facing planar surfaces of the capture plate and the actuator handle; 
     FIG. 5 illustrates a side view of the hub and an actuator strut end; 
     FIG. 6 illustrates a bottom view of the hub; 
     FIG. 7 illustrates a bottom view of the hub accommodating the inboard ends of a plurality of struts; 
     FIG. 8 illustrates a bottom view of the hub rotated counterclockwise, as viewed from the bottom, to outwardly position the struts; 
     FIG. 9 illustrates a side view of the cam style hub and strut system along line  9 — 9  of FIG. 8 having the struts locked in the extended position by the hub; and, 
     FIG. 10 illustrates a side view of the cam style hub and strut system where the hub has been rotated clockwise to disengage and unlock the struts from the over-the-center lock mode and from the capture detents. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 illustrates a cam style hub and strut system  10 , the present invention, engaging a portable or semi-permanent panel  12  shown in dashed lines. Although only one cam style hub and strut system  10  is shown engaging one panel, it should be appreciated that a plurality of panels such as panel  12  can be incorporated in juxtaposition to form a portable or semi-permanent structure incorporating several of the cam style hub and strut systems  10 . The cam style hub and strut system  10  includes a cam style hub herein called the hub  14  preferably of Zytel or other suitable plastic, metal, or suitable material. A plurality of struts  16   a,    16   b,    16   c  and  16   d  extend forcibly and outwardly from the hub  14  to engage the corners of the panel  12  to stretch or otherwise suitably form or shape the panel  12 . Pockets  58   a - 58   d  are sewn or glued onto ends of the panel  12  material for receiving the strut ends. In the alternative, any suitable panel fastening structure can be secured onto the ends of the struts by any suitable known process, such as glue, adhesives, lacing composed of string or thread, or even hook and loop materials. The struts  16   a - 16   d  are of flexible or rigid construction such as, but not limited to, fiberglass, plastic, steel rod and the like. The panel fastening structure can be on the panel, the struts, or both. 
     FIG. 2 illustrates an isometric view of the hub  14  and the inboard ends of the struts  16   a - 16   d . The hub  14  is a split and subsequently mated assembly having a configured actuator handle  18  and a configured capture plate  20 . The actuator handle  18  and the capture plate  20  secure over and about and capture the ball ends  22   a ,  22   b ,  22   c  and  22   d  of the struts  16   a ,  16   b ,  16   c  and  16   d , respectively, which are shown for clarity exterior to the hub  14 . A plurality of accommodational maneuvering channels  24 ,  26 ,  28  and  30  are located and formed between the actuator handle  18  and the capture plate  20 . The accommodational maneuvering channels  24 ,  26 ,  28  and  30  are spaced at 90 degree intervals with respect to each other to intersect sockets  32 ,  34 ,  36  and  38 , respectively, within the hub  14 , as partially illustrated in this figure and as illustrated in FIG.  6  and other figures as required. Movement of the ball ends  22   a ,  22   b ,  22   c  and  22   d  of the struts  16   a ,  16   b ,  16   c  and  16   d  within the accommodational maneuvering channels  24 ,  26 ,  28  and  30  is best understood by further description of the accommodational maneuvering channels  24 ,  26 ,  28  and  30 . Accommodational maneuvering channel  24 , being in all respects similar to and having features and components similar to accommodational maneuvering channels  26 ,  28  and  30  is now described. Reference is also made to FIGS. 4 and 6 wherein accommodational maneuvering channel  24  extends substantially horizontally within the hub  14  and is substantially V-shaped and, in the actuator handle  18 , includes a horizontally aligned planar surface  40  between an inwardly extending arced surface  42  and another inwardly extending arced surface  44 . The planar surface  40  and arced surfaces  42  and  44  form a contiguous surface which intersects an upper and partial socket portion  32   a . In the capture plate  20  a truncated slot  46  extends inwardly in juxtaposition with the arced surface  42  to intersect a lower and partial socket portion  32   b . Also intersecting the lower and partial socket portion  32   b  is an inwardly extending arced surface  48  which juxtaposes the arced surface  44  of the actuator handle  18 . The arced surface  48  is slightly greater than  450  and the arced surface  44  is 45° which in combination forms an arc of just slightly more than 90° which provides for a low pressure capture detent  50  useful for snap-engagement of the strut  16   a  within the capture detent  50  during operation of the invention. The ball end  22   a  is captured during assembly of the actuator handle  18  and the capture plate  20 . 
     With respect to the horizontal, the strut  16   a  can be accommodated and maneuvered horizontally about the intersection of the ball end  22   a  and the socket  32 . Horizontal movement of the strut  16   a  is allowed along the planar surface  40  and between the arced surface  42  and the capture detent  50 . Capture of the strut  16   a  within the capture detent  50  discourages horizontal movement and restricts vertical maneuvering of the strut  16   a . With respect to the vertical positioning of the strut  16   a  such as for collapsing of the cam style hub and strut system  10  and associated panel  12 , the strut  16   a  must be maneuvered and positioned out of the capture detent  50  and aligned to the arced surface  42  which also places the strut  16   a  in alignment with the truncated slot  46  whereby the strut may be rotatingly positioned along the truncated slot  46  and maneuvered vertically, thereby placing the axis of the strut  16   a  perpendicular to the hub  14 . 
     FIG. 3 illustrates a perspective and inverted bottom view of the hub  14 . Illustrated in particular is the truncated slot  46  typical to other truncated slots in the invention. Also visible are the heads of a plurality of screws  52   a - 52   n  which secure the capture plate  20  to the actuator handle  18 . Other securing processes can include gluing, adhesives, welding, snap-fit, etc. 
     FIG. 4 illustrates an isometric view of the capture plate  20  with the actuator handle  18  rotated at an angle with respect to the capture plate  20  to reveal the inwardly facing planar surfaces  54  and  56 , respectively, of the capture plate  20  and the actuator handle  18 . Illustrated in particular is the upper and partial socket portion  32   a  in the actuator handle  18  and the lower and partial socket portion  32   b  in the capture plate  20  which in joined and mated combination form the socket  32 . In a similar fashion, planar surface  56  on the lower region of the actuator handle  18  aligns and mates to a corresponding planar surface  54  on the upper region of the capture plate  20  to additionally align upper and partial socket portions  34   a,    36   a  and  38   a  of the actuator handle  18  with the corresponding lower and partial socket portions  34   b,    36   b  and  38   b  of the capture plate  20  to form sockets  34 ,  36  and  38 . 
     FIG. 5 illustrates a side view of the hub  14  and an end of actuator strut  16   a , where all numerals correspond to those previously described. 
     FIG. 6 illustrates a bottom view of the hub  14 , where all numerals correspond to those previously described. 
     MODE OF OPERATION 
     FIG. 7 illustrates a bottom view of the hub  14  accommodating the inboard ends of struts  16   a - 16   d . The outboard ends of the struts  16   a - 16   d  extend to the end of a panel such as panel  12  shown in FIG.  1  and are secured or captured thereto or therein. The struts  16   a - 16   d  are rotated, for purposes of illustration and example, to the fullest counterclockwise position about the respective ball ends  22   a  - 22   d , and are limited in travel in a counterclockwise position by one side such as the arced surface  42  of the accommodational maneuvering channels  24 ,  26 ,  28  and  30 , respectively, and to also lie against the planar surfaces of the accommodational maneuvering channels  24 ,  26 ,  28  and  30 , such as planar surface  40 . In addition, the inboard strut ends of the struts  16   a - 16   d  are also aligned to the truncated slots  46 . The position of the struts  16   a - 16   d  is shown in the relaxed and non-actuated position and the hub  14  is also shown in the relaxed and non-actuated position. Also referenced in the drawing is distance D 1 , being the distance between the centers of the ball ends  22   a  and  22   c  in the unactuated position. 
     FIG. 8 illustrates a bottom view of the hub  14  rotated counterclockwise, as viewed from the bottom, to outwardly position struts  16   a - 16   d  and tighten an accompanying panel  12 . As the hub  14  is rotated counterclockwise about its center, the ball ends are likewise urged in a counterclockwise direction. At the same time a new distance D 2  between the ball ends  22   a  and  22   c  is created, that distance being larger than distance D 1  in the previous FIG.  7 . With respect to and comparison of the old distance D 1  and the new distance D 2 , it can be seen that the ball ends  22   a  and  22   c  (and ball ends  22   b  and  22   d ) and thus the struts  16   a  and  16   c  (and the struts  16   b  and  16   d ) are further distanced to create a new and increased distance from the outboard tips of the struts  16   a - 16   d  which is applied to the outward reaches of the panel  12 . The struts  16   a - 16   d  are locked by (1) snappingly engaging the capture detents  50  and, (2) over-the-center positioning of opposing strut set  16   a  and  16   c  and strut set  16   b  and  16   d  with relation to each other. At full counter-rotation of the hub  14 , the inboard portion of the strut  16   a  and the remaining struts  16   b - 16   d  align in the capture detents  50 , typical to the accommodational maneuvering channels  24 ,  26 ,  28  and  30 , to opposingly lock over-the-center and positionally fix the struts  16   a - 16   d  with respect to the hub  14  and to each other. 
     FIG. 9 illustrates a side view of the cam style hub and strut system  10  along line  9 — 9  of FIG. 8 having the struts  16   a - 16   d  locked in the extended position by the hub  14 , where all numerals correspond to those elements previously described. Particularly noted is the strut  16   a  which is captured by the capture detent  50 . The elasticity of the hub material is such that entry of and exit from the capture detents  50  by the struts  16   a - 16   d  is accomplished with a nominal amount of rotational pressure as applied to the hub  14  for engagement or disengagement of the hub  14  with the struts  16   a - 16   d.    
     FIG. 10 illustrates a side view of the cam style hub and strut system  10  where the hub  14  has been rotated clockwise to disengage and unlock the struts  16   a - 16   d  from the over-the-center lock mode and from the capture detents  50 , where all numerals correspond to those elements previously described. The hub  14  can be rotated to the full clockwise position positioning the inboard ends of the struts  16   a - 16   d  fully away from the capture detents  50 , thus aligning the inboard ends of the struts  16   a - 16   d  to the opposing arced surfaces  42  at the ends of the accommodational maneuvering channels  24 ,  26 ,  28  and  30  which also places the inboard ends of the struts  16   a - 16   d  in alignment with the truncated slots  46 . Positioning of the inboard ends of the struts  16   a - 16   d  in the truncated slots  46  allows yet another positioning of the struts  16   a - 16   d  in the vertical position, as shown, for collapsing of the struts  16   a - 16   d  and the panel  12  attached thereto. 
     Various modifications can be made to the present invention without departing from the apparent scope hereof.