Abstract:
A windmill compressor apparatus has multiple double acting piston/cylinders actuated by the windmill. The windmill additionally has multiple pairs of blades to enhance power output and lift.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a Continuation-in-Part of two of my prior applications, namely WINDMILL WITH TWO PISTON COMPRESSOR SYSTEM, Serial No. 60/252,772, filed Nov. 22,2000; and APPARATUS AND METHOD OF MOUNTING MULTIPLE BLADES TO ENHANCE PERFORMANCE, Serial No. 60/252,812, filed Nov. 22,2000; the disclosures of which are incorporated herein by reference as if fully set forth. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Technical Field  
           [0003]    This invention relates to improvements in windmill compressed air systems, and more particularly, to a multiple double acting piston/cylinder system actuated by a windmill, which additionally has multiple airfoils in a stack to enhance power output and lift.  
           [0004]    2. Background Art  
           [0005]    In the prior art, it was known to use windmills to compress and store compressed air. Such a system is shown in my prior art U.S. Pat. No. 6,132,181, issued Oct. 17, 2000, which discloses windmill structures and systems. Therein I disclose a number of ways of attaching the rotating shaft of a windmill to various mechanical means and compressors.  
           [0006]    One of the problems that I have noted in my work with windmills is that there may be periods when the wind is either very slow or very fast for a sustained period of time. This can affect the usefulness of the windmill system in compressing and storing compressed air.  
           [0007]    Further, in the prior art, it has been known to mount air foils in stacks, such as the wing  5  arrangement in bi-planes and tri-planes. I have discovered that the performance of such arrangements may be enhanced depending on the mounting and relative positioning of the air foils.  
         DISCLOSURE OF THE INVENTION  
         [0008]    Summary of the Invention  
           [0009]    I have invented a windmill compressed air system which utilizes two double acting pistons and cylinders. These are most preferably of different volume, but have the same stroke length. They have pressure control valves to provide for alternative choices depending on wind availability. The larger diameter piston is used to quickly pump up the volume of the storage tank for the compressed air to a desired level. After that, the smaller diameter piston takes over.  
           [0010]    The larger diameter piston cuts off at lower air speeds, so that at least some useful work can be gained from the windmill turning and driving the smaller diameter piston.  
           [0011]    Further, the improved airfoil arrangement comprises airfoils in combination which provide needed structural strength while causing windmill air flow enhancement which is greater than the sum of the individual air flows (under the same air flow conditions).  
           [0012]    I have invented a windmill compressor apparatus comprising:  
           [0013]    windmill means mounted to a windmill shaft to rotate said shaft in response to air flow through said windmill means;  
           [0014]    multiple double-acting piston/cylinder means each having a piston operating within a cylinder to compress air upon movement of the piston within the cylinder;  
           [0015]    each of said cylinders having a piston shaft connected to said piston therein; said piston shaft extending from said cylinder;  
           [0016]    drive means connecting said piston shafts to said windmill shaft to drive said piston shafts in response to rotation of said windmill shaft; and  
           [0017]    conduit means connected to the piston/cylinder means to permit the flow of air into said cylinders to receive compressed air from said cylinders.  
           [0018]    I have further invented a windmill compressor apparatus in which I position the multiple double-acting piston/cylinder means such that the cylinders are radially space from one another.  
           [0019]    Most preferably, the cylinders are of different diameters. Pressure relief valves are disposed in discharge lines exiting said cylinders of different diameters. The pressure relief valve for the cylinder with the largest diameter is set to be actuated at a pressure which is less than the pressure relief valve for the cylinder with the smaller diameter.  
           [0020]    The drive means comprises a crank arm attached to the windmill shaft to rotate therewith; said crank arm having a portion thereof connected to the piston shafts to rotate said piston shafts, thereby withdrawing and inserting the shafts with respect to the cylinders to compress air. The crank arm has a portion thereof opposite to the end which is connected to the piston shafts, which portion acts as a counterbalance to the pistons.  
           [0021]    The windmill compressor apparatus as defined above may further comprise multiple pairs of windmill blades. The multiple pairs of blades are attached to multiple hubs on said windmill shaft.  
           [0022]    The blades in each pair of windmill blades are interconnected with braces.  
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0023]    [0023]FIG. 1 is a rear view of a windmill system;  
         [0024]    [0024]FIG. 2 is a side view of the windmill system shown in FIG. 1; and  
         [0025]    [0025]FIG. 3 is a top view of a portion of the windmill system shown in FIG. 2. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0026]    Referring to the Figures, they show a windmill system apparatus which comprises a windmill designated generally  10  having a plurality of blades  12  mounted to a hubs  14  and  15  connected to a shaft  16  which is journaled in bearings  18  mounted on a horizontal beam  20  which is rigidly connected to a vertical tube  22  and a base  24  supporting the entire structure.  
         [0027]    Referring to FIG. 2, this shows a side view of a plurality of air foils or blades  12  positioned with respect to one another. The blades are shown as being predominantly flat, of uniform crosssection and having a lip at the down wind edge (as shown in my prior U.S. patents for air foils and windmill structures such as U.S. Pat. No. 6,132,181, issued Oct. 17, 2000). The blades are positioned with respect to one another such that the center of the central portion of one blade is spaced approximately 50% of the blade cord length from the center to the center of the central portion of the other blade.  
         [0028]    I discovered that this arrangement provides for more air flow deflected in a downward direction.  
         [0029]    [0029]FIG. 2 shows the mounting at the ends of the blades to the hub plates  14  and  15 . In this arrangement, additional braces  17  and  19  may be provided for the purposes of stiffening.  
         [0030]    A plurality of such blade arrangements are provided spaced radially from one another.  
         [0031]    The outboard end of the shaft  16  is connected for rotation to a crank arm  28 . One end  29  of the crank arm  28  is “T” shaped and is used to counterbalance the stroke of the pistons in the piston/cylinders  42 , 44 . The other end  30  of the crank arm has a shaft  32  extending therefrom which supports bearings  34  and  36 . Mounting means disposed about these bearings support and are connected respectively to the piston shafts  38  and  40  of the dual acting piston/cylinders  42  and  44 , respectively. The other ends of the air cylinders are mounted to be pivoted on bases  46  and  48 , respectively.  
         [0032]    In operation, as the windmill rotates, it turns the shaft  16  which, in turn, rotates the crank arm  28 . Since the shafts  38  and  40  of the pistons are journaled to the shaft  32 , as the crank arm rotates, it drives the pistons in and out of their respective cylinders. One of these cylinders of the piston/cylinder  44  is of a greater diameter than the other,  42 . Both of the cylinders are double acting and both have the same stroke length on rotation of the crank arm. However, they are spaced radially so as to sequence top and bottom dead center points (by approximately 30 degrees), thereby distributing the loading over a longer duration of rotation and reducing the maximum force needed for a given pounds per square inch/cubic feet per minute rate.  
         [0033]    Referring to the Figures, they show the air exchange system using these two piston/cylinders.  
         [0034]    Since there are check valves at each end of the cylinders, each cylinder is double acting in that on the withdrawal stroke of the piston shafts  38 ,  40 , compressed air is forced out of the upper end of the cylinders of the piston/cylinders  42 ,  44  in FIG. 3; and on the down stroke, compressed air is forced out of the lower end of the cylinders. There are check valves  50 ,  52 , FIG. 2, at both ends to keep the air from flowing back in once it has been exhausted from the cylinder. There are also check valves  54 ,  56 , FIG. 2, at the air intake to keep the air from flowing out once it has been drawn into the cylinder. Down stream of the exhaust check valves, such as  50  and  52 , there are adjustment relief valves  57 ,  59  which will be discussed more fully hereinafter. Also, downstream of the check valves are check valves  58 ; to keep air from flowing back into the system. Downstream from that valve  58 , there is a hose or piping  60  to the compressed air reservoir tank  62 . The same piping system is provided for both cylinders.  
         [0035]    System Operation  
         [0036]    In operation, the pressure relief valves  57 ,  59  are set at predetermined pressures. For example, for the bigger diameter cylinder  44 ; relief valve  57  might be set at 55 or 60 pounds per square inch. For the smaller diameter cylinder, pressure relief valve  59  might be set at approximately 86 pounds per square inch pressure. Thus, after the pressure reaches 55 psi, the valve  57  simply exhausts its compressed air. Therefore, the windmill does not have to push against the combined forces of the bigger and smaller piston/cylinders. Once that pressure is reached, the smaller piston/cylinder nevertheless keeps working and keeps compressing air up to its limit of approximately 86 pounds.  
         [0037]    The smaller cylinder is designed to work with winds of approximately 6 to 10 mph. Once the volume is reached in the tank  62  and the lower pressure limit is reached, the bigger diameter cylinder drops out of the production of compressed air, so that at least something is gained from the windmill system. Otherwise, the windmill would stall because it cannot drive both pistons at low speeds. Thus, this arrangement extends the range of useful work that the windmill can perform.  
         [0038]    Note that when no pressure is in the tank  62  and the windmill first starts up, both cylinders pump compressed air into the storage tank as pressure in the tank climbs to the preset pressure of the larger cylinder.