Patent Publication Number: US-9884473-B1

Title: Carbon fiber tubular pole and method of manufacture

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     This invention relates generally to the construction and manufacture of tubular pole members having a distinctive appearance of black carbon fiber, and more particularly to such a pole or contoured support member and method of forming same at a substantially reduced cost of manufacture. 
     Description of the Related Art 
     Tubular poles and structural contoured members formed of sleeve carbon fiber are well known. The enhanced strength and overall appearance of the black carbon fiber material greatly enhances the strength and aesthetic value despite the greatly exaggerated cost of manufacturing such a product in lieu of similar conventional tubular aluminum product. However, the well-known method for manufacturing such a carbon fiber pole which may typically only be made in a shorter, straight configuration in the carbon fiber industry is through the use of high-tech procedures such as autoclaving and microfilament machines which enable the removal of a mandrel prior to the complete curing of resin saturated into the carbon fiber material. Moreover, when manufacturing smaller diameter carbon fiber tubular members having a diameter of less than 1″, removal of the support mandrel becomes exceedingly difficult. 
     Further, because the cured carbon fiber tubular structure cannot be formed to produce a curve such as for a bow support for a bimini top of a boat, there are no such carbon fiber products in the marketplace at this time. 
     The present invention provides both a structure and a method for producing both straight tubular and curved tubular support members formed of carbon fiber to provide the strength and distinctive appearance of the black sleeve while substantially reducing the cost of manufacture by simply leaving a sacrificial tubular mandrel in place within the end product structure. A mandrel is any tube made of a synthetic or fibrous material that has the properties of being round, hollow and lightweight. Examples of a synthetic pole may be PVC tubing, plastic tubing or fiberglass tubing. Such a mandrel is preferably in the form of either a light-weight tubular polyvinylchloride (PVC) tubing or cardboard tubing which are left in place and cured and become a monolithic part of the entire structure. 
     The foregoing has outlined some of the more pertinent objects of the present invention. These objects should be construed as being merely illustrative of some of the more prominent features and applications of the invention. Many other beneficial results can be obtained by modifying the invention within the scope of the invention. Accordingly other objects in a full understanding of the invention may be had by referring to the summary of the invention, the detailed description describing the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings. 
     SUMMARY OF THE INVENTION 
     The present invention is defined by the appended claims with specific embodiments being shown in the attached drawings. For the purpose of summarizing the invention, the invention relates to an improved carbon fiber tubular pole and curved tubular structural member and method of construction thereof. The end product includes a left in-place lightweight mandrel, preferably formed of tubular synthetic or fibrous, which substantially reduces cost of manufacture. Moreover, an outer tubular layer of glass fiber over a tubular carbon fiber layer and cured resin saturated through and through fiber layers maintains the aesthetic appearance of the black carbon fiber while substantially strengthening the end product. 
     The method is also incorporated into the forming of a socket in one end of the carbon fiber tubular pole for receiving a end of an adjacent fiber tubular pole. 
     It is therefore an object of this invention to provide carbon fiber tubular poles and curved support members which have the outward aesthetic appearance of flat black carbon fiber sleeve. 
     Still another object of this invention is to provide a carbon fiber tubular structure formed leaving an inner tubular mandrel in place within the structure as a manufacturing support to substantially reduce manufacturing costs. 
     Yet another object of this invention is to provide a carbon fiber tubular structure which is formed over a precontoured or curved tubular mandrel so as to overcome the limitation that tubular carbon fiber poles currently prohibit the contouring of cured carbon fiber pole stock after the resin has been hardened and cured. 
     Yet another object of this invention is to provide a method of forming tubular carbon fiber members utilizing slow rotation of the member as the resin is applied to fully saturate the carbon fiber and glass fiber layers all of the way to the tubular mandrel which insures a monolithic-like structure when cured. 
     The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative and not limiting in scope. In various embodiments one or more of the abovedescribed problems have been reduced or eliminated while other embodiments are directed to other improvements. In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions. 
     The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in connection with the accompanying drawings in which: 
         FIG. 1  is a side perspective of one end product produced by the methodology of the disclosure. 
         FIG. 2  is a side perspective view of another end product produced by the methodology of the disclosure. 
         FIG. 3  represents a first step in the manufacture of a pole by the teaching of this disclosure. 
         FIGS. 3 to 15  are side perspective views showing the preferred steps in implementing the method of this disclosure to produce one embodiment of an end pole product of this disclosure. 
         FIG. 16  is a side perspective view showing inserting an alternate support tube within the tubular mandrel for temporarily supporting larger diameter poles during manufacture. 
         FIG. 17  shows an optional step in the resin curing process for the tubular pole produced in  FIG. 16  within the scope of this disclosure. 
         FIGS. 18 and 19  show an optional and preferred step of applying a resin/silica coating over the cured resin ( FIG. 18 ) and hanging the end product vertically for curing. 
         FIG. 20  is a perspective view of a finished tubular carbon fiber pole. 
         FIG. 21  is a section view in the direction of arrows  21 - 21  in  FIG. 20 .  FIG. 21A  is an enlarged view of a segment of pole section in  FIG. 21 . 
         FIG. 22  shows three perspective views of two alternate embodiments of a bimini top support bow or member as well as an exploded view of the second embodiment thereof. 
         FIGS. 23 to 30  are side perspective views showing steps in implementing an alternate method of this disclosure to produce a socket in an end pole product of this disclosure. 
         FIG. 31  is an assembled view of a first pole section of  FIGS. 3 to 15  inserted into the socket of a second pole section of  FIGS. 23 to 30 . 
         FIG. 32  is a sectional view along line  32 - 32  in  FIG. 31 . 
         FIG. 33  is a view of the first and second pole sections of  FIG. 30  in a folded position. 
     
    
    
     Exemplary embodiments are illustrated in reference figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered to be illustrative rather than limiting. Similar reference characters refer to similar parts throughout the several Figures of the drawings. 
     DETAILED DISCUSSION 
     The following nomenclature is used throughout the specification and drawings.
       10 . boat pole assembly     12 . pole assembly     14 . pole     16 . boat hook     18 . finishing end cap     20 . bimini brace assembly     22 . brace assembly     24 . brace     26 . end pivot fitting     28 . mid-pivot bracket     30 . PVC mandrel     32 . support rod     34 . mandrel outer surface     36 . driving notch     38 . carbon fiber sleeve     40 . glass fiber sleeve     42 . uncured resin     42 ′. cured resin     44 . uncured resin/silica     44 ′. cured resin/silica     46 . pole assembly     48 . large pole     50 . PVC mandrel     52 . carbon fiber sleeve     54 . glass fiber mat     56 . cured resin     58 . cured resin/silica     60 . PVC bimini mandrel     62 . bow segment     64 . corner segment     66 . upright leg     70 . segmented PVC bimini mandrel     72 . bow segment     74 . upright leg     76 . corner segment     78 . connector tube     80  socket     90  bell mandrel     91  narrow cylindrical portion     92  tapered portion     93  enlarged cylindrical portion     101  first pole section     101  second pole section     110  end unit     111  end unit     112  washer stop     114  recess     120  elastic cord     122  canvas snap   

     Referring now to the drawings, and firstly to  FIGS. 1 and 2 , two finished products produced by the methodology of the present disclosure are there shown generally at numerals  10  and  20 . In  FIG. 1 , the boat pole assembly  10  is formed of an elongated pole assembly  12  which includes a tubular carbon fiber pole  14  having a finishing end cap  18  which lockingly receives a boat hook  16  held therewithin, the shaft of which extends partway into the tubular pole  14 . The finished appearance shown as being transparent is that of a longitudinally stranded carbon fiber linear sleeve therebeneath. In  FIG. 2 , a bimini brace is shown at  20  and also includes an elongated carbon fiber brace assembly  22  formed of an elongated tubular carbon fiber  6  pole  24 . The bimini brace  20 , being shown as a product example, also includes an end fitting  26  and a mid-span pivot bracket  28  lockingly positioned and functioning in a conventional manner. 
     Referring now to  FIGS. 3 to 15 , the methodology of this disclosure producing the product shown typically shown in  FIGS. 1 and 2 , is there shown. In  FIG. 3 , an elongated removable support rod  32 , preferably formed of aluminum or copper, is inserted into a length of polyvinylchloride (PVC) mandrel  30 , the PVC mandrel  30  forming a permanent part of each end product. The support rod  32  is slid into the hollow interior of the mandrel  30  in the direction of arrow A. Thereafter, the outer surface  34  of the mandrel  30 , supported by the support rod  32 , is sanded and roughened so as to better adhere to resin applied thereover in a later step. 
     As seen in  FIG. 5 , driving notches  36  are formed into one end of the mandrel  30  after which a plug guide is slid part way into that same end of the mandrel  30  in the direction of arrow B. The rounded distal end of the plug guide is left exposed so that, as seen in  FIG. 7 , a length of tubular carbon fiber sleeve  38  may be easily slidingly engaged onto the outer surface of the mandrel  30  in the direction of arrow C. Once this carbon fiber sleeve  38  is fully in place over the mandrel  30  as shown in  FIG. 8 , the carbon fiber sleeve  38  is manually stretched as arrow D in the direction of arrows E in  FIG. 9  so as to more tightly conform against the exterior surface of the mandrel  30 . Thereafter, as seen in  FIG. 10 , a length of tubular glass fiber sleeve  40  is slid over the top of the carbon fiber sleeve  38  in the direction of arrow F. Once the glass fiber sleeve  40  is in position over the previously stretched and tensioned carbon fiber sleeve  38 , the glass fiber sleeve  40  is also stretched in the direction of arrows G and tensioned in the direction of arrows H by manual manipulation thereof to insure outstretched and tightened position of the glass fiber sleeve  40 . This manipulation is similar to the collapsing and tightening of “Chinese handcuffs”. 
     The preferred carbon fiber sleeve is formed of either tubular biaxial or unidirectional carbon fiber material. The preferred glass fiber sleeve is roving biaxial sleeving. 
     This entire arrangement shown in  FIG. 12  is then positioned onto a rotary apparatus by sliding the driving notch  36  into engagement on driving pin of the drive shaft of the rotary, after which the support shaft is moved into the opposite end of the mandrel  30  in the direction of arrow J. 
     The rotary is then activated to slowly (about 1 to 5 RPM) rotate the mandrel  30  in the direction of arrow L simultaneously with brush application of uncured resin  42  applied over all of the exterior surface of the glass fiber sleeve  40 . The resin  42  may be vinyl or polyester epoxy and of sufficiently low viscosity so as to fully penetrate through both the glass fiber sleeve  40  and the carbon fiber sleeve  38  to fully saturate those layers down to the outer surface of the mandrel  30 . As seen in  FIG. 15 , thereafter a user wearing protective vinyl or latex gloves then smoothes the entire arrangement of resin  42 , glass fiber and carbon fiber sleeves  38  and  40  by movement manually in the direction of arrows M while squeezing. The preferred resin is a low viscosity epoxy using a non-flushing hardener, slow, medium, or fast curing depending upon ambient temperature. 
     For smaller diameter products, curing of the resin may take place while being held with or without rotation within the rotary shown in  FIG. 15 . However, where the diameter of the end product exceeds about 1″, it is preferred that a support tube be inserted into the mandrel  30  as shown in  FIG. 16 . The mandrel  30 , being non-porous with respect to uncured resin  42 , will prevent any resin  42  from contacting the outer surface of the support tube, eliminating any risk that the support tube may not be easily removed after the resin  42  applied to the outer surface shown in  FIGS. 14 and 15  has cured. 
     Once this support tube is inserted in the direction of arrow N as seen in  FIG. 16 , the ends of the support tube may be held horizontally or, as seen in  FIG. 17 , for larger diameter end product, the support tube may be attached to and hung vertically by a hanger at an upper end and, to prevent the mandrel  30  from sliding downwardly, a stop pin may be inserted through the opposite end of the support tube. The work product is being held vertically so as to insure a perfectly straight pole end product and without the risk of the resin running which is insured by the careful, even distribution of all uncured resin in the step shown in  FIG. 15 . 
     In  FIG. 18 , after the resin  42  has been cured and hardened, it is preferred that an outer layer of resin in combination with a small quantity of colloidal silica at  44  be brush applied while rotating the work product. Alternately, the entire arrangement is then removed from the rotary into an upright orientation shown in  FIG. 19  wherein the hanger is attached to an overhead support after a stop pin has been positioned through. 
     a transverse aperture through the support tube at the opposite end thereof. The colloidal silica/resin outer coat  44 ′ provides a more serviceable and smoother surface. 
     Referring now to  FIGS. 20, 21 and 21A , a segment of a length of carbon fiber pole is there shown at  46 . Again, the finished carbon fiber  48  has a translucent or transparent visual effect through the cured resin  56  and the outer glass fiber sleeve  54  so that the black carbon fiber sleeve  52  is visible through these combined layers of resin and glass fiber sleeve. As seen in  FIG. 21B , the preferred embodiment also includes the outer layer of cured resin with colloidal silica  58  which is applied manually over the cured surface of the resin  56  as previously described. 
     Referring now to  FIG. 22 , the tubular mandrel aspect of the present invention 
     is applied to curved tubular structural members such as the support bow of a bimini top of a sailboat or power boat. In one embodiment  60 , the PVC mandrel  62  is heated and formed at  64  so as to provide straight upright legs  66  and a large radius curved center portion  62  configured as aesthetically dictated for the bimini canvas. Alternately, the PVC mandrel may be formed in segmented portions at  70  wherein the center portion  72  is first heated and formed around a suitable form or manually and then interconnected to tightly bent corners  76  by connectors  78  for attachment to elongated upright tubular portions  74  to form the same desired configuration as with respect to the mandrel  60 . 
     It is again stressed that the important aspect of this invention is that the inner mandrel becomes a permanent part of each hollow carbon fiber pole or contoured product. The resin is saturated through the outer layer of glass fiber and through the inner layer of carbon fiber sleeve to reach and become a monolithic part with the inner tubular mandrel which again may be formed of polyvinylchloride material, cardboard material or any other suitable material which affords a lightweight tubular inner form over which the carbon fiber sleeve, the glass fiber sleeve, and the resin are applied. While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations and additions and subcombinations thereof. It is therefore intended that the following appended claims and claims hereinafter introduced are interpreted to include all such modifications, permutations, additions and subcombinations that are within their true spirit and scope. 
       FIGS. 23 to 30  are side perspective views showing steps in implementing an alternate method of this disclosure to produce a socket  80  in an end pole product of this disclosure. 
       FIG. 23  illustrates a plug guide being slid part way into one end of the mandrel  30  in the direction of arrow B. A bell mandrel  90  has a narrow cylindrical portion  91 , an enlarged cylindrical portion  92  and an intermediated tapered portion  93 . The narrow cylindrical portion  91  is inserted into the other end of the mandrel  30   
       FIG. 24  illustrates a length of tubular carbon fiber sleeve  38  being slidingly engaged onto the outer surface of the mandrel  30  in the direction of arrow C. 
       FIG. 25  illustrates the carbon fiber sleeve  38  is fully in place over the mandrel  30  and the intermediated tapered portion  93  and the enlarged cylindrical portion  92  of the bell mandrel  90 . 
       FIG. 26  illustrates the carbon fiber sleeve  38  being manually stretched as arrow D in the direction of arrows E so as to more tightly conform against the exterior surface of the mandrel  30  and the intermediated tapered portion  93  and the enlarged cylindrical portion  92  of the bell mandrel  90 . 
       FIG. 27  illustrates a length of tubular glass or carbon fiber sleeve  40  is slid over the top of the carbon fiber sleeve  38  in the direction of arrow F. 
       FIG. 28  illustrates the length of tubular glass or carbon fiber sleeve  40  positioned over the previously stretched and tensioned carbon fiber sleeve  38  overlaying the intermediated tapered portion  93  and the enlarged cylindrical portion  92  of the bell mandrel  90 . 
       FIG. 29  illustrates the glass or carbon fiber sleeve  40  being stretched in the direction of arrows G and tensioned in the direction of arrows H by manual manipulation thereof to insure outstretched and tightened position of the glass fiber sleeve  40 . 
       FIG. 30  illustrates the entire arrangement shown being positioned onto a rotary apparatus in a manner similar to the explanation previously referred to with reference to  FIG. 13 . The assembly is process in a manner as set forth in  FIGS. 14 to 19 . Thereafter the bell mandrel is removed to from the formed socket  80 . 
       FIG. 31  is an assembled view of a first pole section  101  of  FIGS. 3 to 15  inserted into the socket  80  of a second pole section  102  of  FIGS. 23 to 30 . The integral socket enables the first pole section  101  to be inserted into the socket  80  of the second pole section  102  without the need for ferrules. The integral socket provides an increased strength and reduced the cost of the carbon fiber tubular pole. 
       FIG. 32  is a sectional view along line  32 - 32  in  FIG. 31  illustrating an end unit  110  of the first pole sections  101 . The second pole section  102  is fitted with a similar end unit  111 . The end unit  110  comprises a washer stop  112  disposed in a recess  114  formed in the end of the first pole sections  101 . An elastic cord  120  is stretched between the end unit  110  of the first pole sections  101  and a similar end unit  111 . The elastic cord  120  maintains the first pole sections  101  inserted within the socket  80  of the second pole section  102 . The end units  110  and  11  also include a canvas snap  122  (lift-a-dot) for mounting a canvas awning or the like. 
       FIG. 33  is a view of the first and second pole sections of  FIG. 30  in a folded position. The first pole section  101  is removed from the second pole section  102  and may be bent 180 degrees for easy storage. 
     The present disclosure includes that contained in the appended claims as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.