Abstract:
A wind machine comprises a plurality of fabrics that are removeably installed on a rotatable carrier. The carrier axis of rotation may be either horizontal or vertical. The carrier has pairs of first and second arms that support opposite ends of a fabric net. Side strands of the net may be reinforced. Each net has a loop that is supported on one carrier arm and a piece of material that is supported on the second carrier arm. The fabric piece of material has holes that receive associated studs on the carrier second arm, which is turnable. By turning the carrier second arm, a tension is imparted to the fabric. The carrier second arm is lockable to maintain the tension. Multiple panels are connected to the net for pivoting between closed and open positions. The panels resist the wind when they are in the closed position.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention pertains to energy conversion, and more particularly to apparatus that converts wind energy into mechanical or electrical energy. 
   2. Description of the Related Art 
   It has long been known to harness the wind to perform useful work. For example, sailboats and water-pumping windmills have been in use for centuries. 
   Many wind powered machines utilize blades that are fixed to a supporting frame. Those types of machines typically have an axis of rotation for the blades and frame that is generally parallel to the direction of wind flow. In that case, the blades rotate in a plane that is perpendicular to the direction of the wind. Another type of wind machine utilizes a frame that rotates about an axis that is perpendicular to the wind direction. In that type of machine, the blades are not fixed to the supporting frame. Rather, the blades pivot such that the wind strikes the blades&#39; full areas so as to push the blades against the frame when the blades move in the same direction as the wind. The blades pivot such that the wind passes through them when the blades move in the opposite direction as the wind. 
   Some specific applications of prior attempts to convert wind energy into mechanical energy by using pivotable blades may be seen in U.S. Pat. Nos. 23,932; 41,442; 1,753,302; 2,006,024; 2,129,652; 4,408,955; and 4,649,284. U.S. patent publication 2002/0187038 shows similar apparatus. U.S. Pat. Nos. 4,134,710 and 5,525,037 disclose prior machines that convert wind energy into electricity. 
   U.S. Pat. No. 3,920,354 teaches a wind machine in which the blades are hinged to a series of mutually perpendicular wires. In turn, the wires are part of a frame that rotates about an axis of rotation. A similar design is shown in U.S. Pat. No. 4,684,817 and United Kingdom patent application GB2048391. The wire and blade design of the two foregoing U.S. patents and the United Kingdom patent application suffer the disadvantage of having the wires integral with the frame. That is, the ends of the wires are permanently fixed directly to the associated machine frame component. Consequently, the assembly of the blades to the wires can be achieved only in the presence of the frame. Such assembly is often awkward. Further, if a blade or wire is damaged, the entire machine is out of operation while repairs are made. 
   Thus, a need exists for improvements to wind machines. 
   SUMMARY OF THE INVENTION 
   In accordance with the present invention, a wind machine is provided that includes a fabric that is independent of a machine carrier. This is accomplished by apparatus that includes a net that is removably supported on the carrier and multiple panels pivotally connected to the net. 
   The wind machine comprises a frame having a base in which the carrier rotates. A preferred carrier has at least three pairs of arms. The pairs of arms are preferably spaced equiangularly about a carrier axis of rotation. At least one arm of each pair is turnable and lockable relative to the rest of the carrier. On the turnable arm are a number of studs. 
   The fabric net is made with a number of first strands that intersect a number of second strands. Preferably, the first and second strands are perpendicular to each other and are joined at their intersections. A suitable material for the net is a flexible plastic. In that situation, the intersections of the strands may be heat welded to each other. 
   The fabric net may have a variety of shapes such as circular, triangular, or rectangular. The net periphery is designed to be removably supported on the carrier. For a rectangular net, for instance, at least two opposed ends are constructed to be supported on the carrier. Opposed sides of the net may be either supported or unsupported on the carrier. 
   According to one aspect of the invention, one of the ends of the fabric net is provided with a loop. The loop may be a separate piece of flexible material. Alternately, the net may be doubled over onto itself into a loop and overlapping strands joined to each other. On the other end of the net is flat piece of cloth or other flexible material. The cloth piece has a number of holes in it, which may be reinforced with grommets. The strands at the second sides of the net may be stiffened by using thicker strands or double strands. 
   The panels of the invention are made from any of a wide variety of materials such as plastic or metal. The panels may be rectangular in shape, but the particular shape is not critical to the operation of the invention. The panels are thin in relation to their lengths and widths. 
   A first edge of each panel is pivotally connected to a strand of the net. The connection may be on either a first strand or on a second strand. In the preferred embodiment, the panels are arranged in rows on the net, with several relatively small panels being connected along a particular common strand to make a row. The panels of one row may partially overlie the panels of an adjacent row. The pivotal connections may consist of one or more tabs along the panel first edge. The tab is bent over to capture the associated strand and to lie in flat facing contact with a panel plate section. Other pivotal connections such as clips, clasps, and hinges are also acceptable. By means of the pivotal connections, the panels are free to pivot between open and closed positions on the net. In the closed position, the panels lie alongside the net. In the open position, the panels are approximately 90 degrees to the closed position. 
   The fabrics are installed on the carrier by sliding the net loop over one arm of a pair. The grommets on the net cloth piece are slipped over the studs on the turnable arm of the pair. The two carrier arms are spaced apart such that the fabric lies in a generally flat plane. The carrier turnable arm is turned to impart a desired tension on the fabric, and the arm is locked in place. 
   At least three fabrics of the invention are installed on the carrier of the wind machine. In one embodiment of the invention, the carrier is journalled in the base for rotating about a vertical axis. The fabrics are oriented in a generally vertical plane with the net: first strands being generally horizontal and the net second strands being generally vertical. In that situation, the panels initially hang down by gravity alongside the net in the closed position if the panels are pivotally connected to the first strands. 
   The wind machine is placed out of doors in the path of wind. Regardless of its direction, the wind forces the panels on at least one first fabric to the closed position against the associated net. Simultaneously, the wind forces the panels of at least one second fabric to the open position. The force of the wind on the closed panels tends to cause the first fabric to move in the downstream direction. The open panels on the second fabric present only negligible resistance to the wind. As a result, the carrier rotates about its axis, with the first fabric moving in the downstream direction, and the second fabric moving in the upstream direction. As the carrier rotates, the fabrics remain vertically oriented, and the panels alternately open and close as the corresponding fabrics move upstream and downstream, respectively, relative to the wind. The rotating frame is connected to a device that converts the wind energy acting through the carrier into mechanical or electrical energy. 
   In a modified embodiment of the invention, the wind machine carrier rotates about a horizontal axis. The operation of the machine with the horizontal axis of rotation is generally similar to that of the machine with the vertical axis of rotation. The only significant difference is that the planes of the fabrics change between vertical and horizontal as the carrier rotates. 
   Should a fabric need repair or replacement, it is removed from the wind machine carrier by releasing the tension on the fabric. A new fabric is installed and tensioned, and the wind machine is quickly back in operation. In that manner, unproductive downtime is minimal. 
   The method and apparatus of the invention, using fabrics having pivotable panels, thus enables a wind machine to convert wind energy into mechanical or electrical energy. The fabrics are removable from the carrier, thereby enhancing the versatility and productivity of the wind machine. 
   Other advantages, benefits, and features of the invention will become apparent to those skilled in the art upon reading the detailed description of the invention and studying the drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the wind machine of the present invention. 
       FIG. 1A  is a perspective view on an enlarged scale showing a portion of a bottom arm of the wind machine of the invention. 
       FIG. 2  is an exploded perspective view of a portion of a typical fabric used with the wind machine of the invention at a first stage of assembly. 
       FIG. 3  is an exploded perspective view of the fabric of  FIG. 2  at a subsequent stage of assembly. 
       FIG. 4  is a perspective view of a partially assembled fabric installed on the wind machine of the invention. 
       FIG. 5  is a front view of a modified panel of the fabric used with the wind machine of the present invention. 
       FIG. 6  is a side view of a portion of the fabric with the panels thereof in a closed position. 
       FIG. 7  is a side view of a portion of the fabric with the panels thereof in an open position. 
       FIG. 8  is a top view of the wind machine in operation. 
       FIG. 9  is a perspective view of an alternate wind machine according to the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto. 
   Looking at  FIG. 1 , a wind machine  1  is illustrated that includes the present invention. The wind machine  1  is particularly useful for converting wind energy into mechanical or electrical energy. However, it will be understood that the invention is not limited to power conversion applications. 
   The particular wind machine  1  illustrated is comprised of a frame  2  having a base  3  and a carrier  7 . The carrier  7  includes an upstanding shaft  5  journalled in the base  3  for rotation about a vertical axis  6 . The particular carrier illustrated is in the form of four pairs  9 A,  9 B,  9 C, and  9 D of arms extending from the shaft  5  and equiangularly spaced about the shaft axis  6 . It will be appreciated, of course, that any number of pairs of arms greater than two is acceptable, but the arms should be equiangularly spaced. Each pair  9 A,  9 B,  9 C, and  9 D of arms consists of a fixed arm, such as top arm  11 , and a turnable arm, such as bottom arm  13 . Along each bottom arm  13  are a number of short studs  14 ,  FIG. 1A . The free ends  16  of the studs  14  may be hooked. The bottom arms are turnable in the directions of arrows  12  about their respective longitudinal centerlines  18  relative to the shaft  5 , and the arms are lockable to the shaft at a desired angular orientation. In  FIG. 1A , double nuts  20  are used on threaded ends  22  of the bottom arms to lock the arms in place. Other locking devices, such as a ratchet or a set screw, may also be used to lock the arms in place. 
   Installed on the carrier  7  are multiple fabrics  15 . Each fabric  15  is removably installed on one pair  9  of carrier arms. Specifically, one fabric is installed between the top and bottom arms  11  and  13 , respectively, of each pair of arms. Thus, the wind machine  1  utilizes four fabrics. 
   Turning to  FIGS. 2 and 3 , each fabric  15  is composed of a net  17  and a large number of panels  19 . The net  17  is preferably made from a flexible weather impervious material, such as plastic or stainless steel wire. The net has a large number of horizontal intermediate strands  21  that intersect and are joined to a number of vertical intermediate strands  23  at junctions  24 . For example, plastic strands  21  and  23  may be heat welded at the junctions  24 . The spacings between the strands is not critical. Typical spacings range from about one-fourth inch to over four inches. 
   The net  17  is bounded by a periphery  25 . The periphery  25  may be any practical geometric shape such as circular or triangular. In the particular fabric  15  shown, the net has a rectangular periphery. The net thus has a top end  26 , a bottom end  28 , and opposite sides  30 . At: the net top end  26  is a top strand  27 . The net also has a bottom strand  29  and opposed side strands  31 . 
   It is an important feature of the invention that the fabric  15  is easily installed onto and removed from the wind machine carrier  7 . For that purpose, the net  17  is constructed with a loop  33  along one of the ends  26  or  28 . In the preferred embodiment, the loop  33  is along the top end  26 . The loop  33  overlaps the top strand  27 , and it may overlap one or more intermediate strands  21 . As illustrated, the loop  33  is a long continuous loop between the side strands  31 . However, several short loops may be used instead of one long loop without departing from scope of the invention. The loop may be made from any suitable material, such as a plastic material. However, I prefer a woven cloth material for the loop. The cloth material is attached to the net in any convenient way, such as by being sewn to itself along one or more stitch lines  35 . 
   Along the net end opposite the loop  33  is a flat piece  37  of cloth or similar flexible material. The cloth piece  37  is shown at the net: bottom end  28 . In that case, the cloth piece  37  overlaps the bottom strand  29 , and, if desired, one or more intermediate strands  21 . The piece  37  is attached to the net by sewing along one or more stitch lines  39  or other suitable way. In the piece  37  are a number of holes with associated grommets  41 . Preferably, the side strands  31  are thicker than the top, bottom, and intermediate strands. Alternately, the side strands may be the same thickness as the other strands but doubled. 
   In the illustrated construction, the panels  19  are constructed with a plate section  43  bounded by a rectangular periphery  45 . It will be appreciated, of course, that the periphery  45  may be of different shapes, such as triangular or circular. On one edge  47  of the plate section periphery are a pair of spaced apart tabs  49 . The tabs  49  are preferably integral with the plate section. The panels may be made from a variety of materials, such as plastic or metal. The material is thin in relation to the plate section length and width. 
   For the fabric  15  of  FIGS. 2 and 3 , the panels  19  are assembled to the net  17  by placing the panel plate sections  43  in flat facing contact with the net. The panel tabs  49  are bent over in line with the edge  47  to capture a horizontal strand  21  between the tabs and the plate section. The tabs are bent so as to come into flat facing contact with the panel plate section, and the tabs are affixed to the plate section, such as with an adhesive. The panels are relatively small in comparison with the area of the net, and several panels are connected to a particular strand. The panels are arranged in rows. For instance, in  FIG. 4  one row R 1  of panels  19 A are connected to the net strand  21 A, and a second row R 2  of panels  19 B are connected to the net strand  21 B. The panels of one row, such as the panels  19 B of row R 2 , may partially overlie the panels of the adjacent row, such as the panels  19 A of row R 1 . If desired, however, the panels may be arranged such that edges  48  of the panels of one row are aligned with the edges  47  of the panels of the adjacent row. 
   The panels  19  normally hang generally vertically by gravity from the tabs  49  and lie in closed positions alongside the net  17 . Also see  FIG. 6 . The panels are pivotable about the net strands  21  to an open position as shown in  FIG. 7 , which is approximately 90 degrees to the closed position. As many panels are assembled to the net as needed to cover substantially the entire area of the net. 
   The fabric  15  is installed on the carrier  7  by supporting the net  17  on a pair  9  of carrier arms such that the fabric lies in a generally flat plane. The net loop  33  is slid over the top arm  11  of a pair of arms. See  FIG. 4 . The grommets  41  in the fabric piece  37  are aligned with and placed over respective studs  14  in the bottom arm  13 . The bottom arm is turned in the direction of arrow  12 A such that the studs cooperate with the top arm to impart a tension on the fabric. The bottom arm is locked in place. In  FIG. 4 , a set screw  50  is shown as locking the bottom arm, but the double nuts  20  of  FIG. 1A  or other means such as a ratchet may also be used. The installation process is repeated for all the fabrics and associated pairs of arms of the carrier. 
   When all the fabrics  15  have been installed on the carrier  7 , the wind machine  1  is complete and ready for operation. Looking at  FIGS. 6 and 8 , it will be assumed that the wind is blowing in the direction of arrow  51 , which is perpendicular to the plane of the fabric on the carrier arm pair  9 A. In that case, the wind  51  forces the closed panels  19  against the net  17  of the fabric on the pair  9 A of arms. Simultaneously, the wind forces the panels on the fabric on the pair  9 C of arms to pivot in the direction of the wind to their open positions,  FIG. 7 . The wind thus passes through the fabric on the arm pair  9 C with but minor resistance. The wind has little if any effect on the fabrics installed on the pairs  9 B and  9 D of arms. 
   The force differential of the wind  51  on the fabrics  15  on the pairs  9 A and  9 C of arms causes the carrier  7  to rotate in the direction of arrow  53  about the shaft axis of rotation  6 . AS the carrier rotates, arm pair  9 D approaches the position shown for arm pair  9 A, and arm pair  9 B approaches the position shown for the arm pair  9 C. The wind then blows against the closed panels  19  on the arm pair  9 D. The wind blows the panels to their open positions on the arm pair  9 B, and the cycle continuously repeats for all the arm pairs as the carrier rotates. 
   The carrier shaft  5  is connected to any of a wide variety of devices in the frame base  3  that utilize the torque available from the shaft. For instance, the shaft may geared to the armature of an electric generator. In that manner, the energy of the wind  51  is converted by the wind machine  1  into electrical energy. Known means, not illustrated, can be used to modify the raw electricity produced by the wind machine into a readily useful form. 
   Should a fabric  15  become worn or damaged, it is an easy task to replace it. The nuts  20 , set screw  50 , or other locking device is unlocked. The bottom arm  13  associated with the fabric to be removed is turned in the direction opposite arrow  12 A to release the tension on the fabric. The grommets  41  are removed from the studs  14 , and the loop  33  is pulled off the associated top arm  11 . A new fabric is installed as described above, and the wind machine  1  is ready for further service with but minimal downtime. 
   Turning to  FIG. 5 , a modified fabric panel  55  is depicted. The panel  55  has a plate section  43 ′ with a periphery  45 ′ that may be circular, triangular, or, as depicted, rectangular in shape. One edge  57  of the periphery  45 ′ is slit in a number of places with slits  59  to make a corresponding number of tabs  61 . The slits  59  are spaced apart the same distance as the spacings of the net strands  21  and  23 . To assemble the panels to the net  17 , the tabs  61  are bent over along respective fold lines  63  to capture a net strand  21  between the tab and the plate section  43 ′. Then the tabs are affixed to the plate section. 
   The versatility of the present invention is further exemplified in  FIG. 9 . A wind machine  69  has a base  71  that defines a horizontal axis  73 . A carrier  75  is free to rotate in the base  71  about the axis of rotation  73 . The carrier  75  has four arm pairs  79 A– 79 D. Each arm pair  79 A– 79 D has at least one arm  80  that is turnable and lockable in the carrier. The arm  80  is provided with a number of studs similar to the studs  14  of the wind machine  1  described previously. 
   Installed on each arm pair  79 A– 79 D is a fabric  81 . The fabric  81  may be substantially similar to the fabric  15  described in connection with  FIGS. 2 and 3 . The fabrics  81  are installed to the carrier  75  in the same way as the fabrics  15 . The planes of the fabrics  81  change between horizontal and vertical as the carrier  75  rotates. In all other respects, the operation of the fabrics  81  and the wind machine  67  are substantially similar to the operation of the fabrics  15  and the wind machine  1 , respectively. 
   In summary, the results and advantages of wind power can now be more fully realized. The wind machine of the invention provides both a way to harness wind energy as well as versatility in the design of the machine. This desireable result comes from using the combined functions of the fabric. The same fabric functions to both resist and yield to wind forces during a cycle of the machine. The fabric panels may be constructed in a variety of ways, and the panels may be assembled to either vertical or horizontal strands of the net. The net loop and grommets cooperate with turnable and lockable machine arms and studs to render the fabrics easy to install, tension, and remove from the carrier. 
   It will also be recognized that in addition to the superior performance of the wind machine of the invention, its construction is such as to cost considerably less that traditional wind powered machines. The independence of the fabrics from the rest of the machine is especially beneficial. That feature enables repair or replacement of a fabric to be made without lengthy machine downtime. 
   Thus, it is apparent that there has been provided, in accordance with the invention, a wind machine with independent fabrics that fully satisfies the objects, aims, and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.