Abstract:
In a preferred embodiment, an apparatus, including: an aircraft having rotatable blades; and the rotatable blades are movable between horizontal and vertical positions.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   The present application is a divisional of U.S. application Ser. No. 10/958,038, filed Oct. 4, 2004, now U.S. Pat. No. 7,226,017 and titled AERODYNAMICALLY STABLE, HIGH-LIFT, VERTICAL TAKE OFF AIRCRAFT. Benefit is claimed of the filing date of U.S. Provisional Application Ser. No. 60/507,530, filed Oct. 2, 2003, and titled FIVE-PIECE FUSELAGE, INCLUDING ENGINES AND WINGS, FOR AN AERODYNAMICALLY STABLE, HIGH-LIFT, VERTICAL TAKEOFF AIRCRAFT. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to vertical take-off aircraft generally and, more particularly, but not by way of limitation, to a novel rotating blade control system for such an aircraft. 
   2. Background Art 
   Vertical take-off aircraft are useful in various situations in which horizontal space is limited. Aircraft are well known means of air transport. Among conventional aircraft are: common airplanes with fixed wings, helicopters with rotating wings, common airplanes with tilting rotors (Osprey), gyrocopters with freely rotating wings creating lift by spinning because vehicle is pushed with regular horizontal motor with propeller, fighter jets with adjustable thrust downwards for takeoff and horizontal thrust to fly (Joint Air Strike Fighter), rockets, and disc-shaped aircraft with internal engine exhaust blowing over airfoil to create lift. 
   A disadvantage of many of these conventional aircraft is that they require a relatively long horizontal distance to take off. Others, such as rockets, are unsuitable for general use. 
   The Osprey suffers from the disadvantage that it has only a lift force or a push force by propellers and during transitional flight, this force is divided. Because of the tilting of the propellers, the vehicle bearing low pressure disc (created by the propellers) gets much smaller and is divided into a vertical part and a horizontal part. But the vertical part needs enough bearing capacity to lift. This is resolved by providing oversized propellers—more than necessary—and this requires more than necessary engine power that is not efficient. Huge propellers are not efficient and are disturbing for straight level flight. During the tilting process, the propellers cut through the downwards directed air stream, reduce efficiency, and make the aircraft very shaky and unsecured. The tilting rotating masses create a gyroeffect and make it very hard to stabilize the aircraft, one movement creating another effect and so on. Sometimes the aircraft is impossible to control and it falls down. 
   Some attempts to provide such an aircraft include the following: 
   U.S. Pat. No. 2,859,003, issued Nov. 4, 1958, to Servanty, and titled AERODYNE, describes a vertical take-off aircraft that has three equally spaced engines spaced apart from the base of a fuselage by vertical wings. Three vertical winglets are disposed near the top of the fuselage. The fuselage is generally bullet-shaped. 
   U.S. Pat. No. 3,045,951, issued Jul. 24, 1962, to Freeland, and titled AIRCRAFT, describes an aircraft in which the four engines thereof are disposed within a fuselage that slopes inwardly and downwardly from a dome-shaped upper portion, but the lower portion is flared outwardly at the bottom thereof. 
   U.S. Pat. No. 3,120,359, issued Feb. 4, 1964, to Sprecher, and titled AIRCRAFT WITH EQUI-SPACED POWER PLANT, describes an aircraft that has four equally spaced engines disposed at an upper end of a fuselage and joined thereto by wings and four interposed wings disposed at a lower end of the fuselage and bearing at their distal ends landing gears. The fuselage is generally bullet-shaped. 
   U.S. Pat. No. 3,252,673, issued May 24, 1966, to Reichert, and titled SUPERSONIC VTOL AIRCRAFT AND LAUNCH VEHICLE, describes an aircraft having two engines disposed on the outside of a cylindrical shroud disposed in approximately the middle of a bullet-shaped aircraft, the shroud being supported from the aircraft by struts. Three wings are disposed at a lower end of the fuselage. 
   U.S. Pat. No. 4,123,018, issued Oct. 31, 1978, to Tassin de Montaigu, and titled HELICOPTER WITH COAXIAL ROTORS, OF CONVERTIBLE TYPE IN PARTICULAR, describes a helicopter that is clearly non-symmetrical. 
   U.S. Pat. No. 4,433,819, issued Feb. 28, 1984, to Carrington, and titled AERODYNAMIC DEVICE, describes a rotatable disk affixed to a central, generally dome-shaped body, the disk including a plurality of selectively vectorable jets. A plurality of reaction jets are attached to the central body. 
   U.S. Pat. No. 5,178,344, issued Jan. 12, 1993, to Dlouhy, and titled VTOL AIRCRAFT, describes, insofar as pertinent, a disk-shaped aircraft having a plurality of rotating sets of rotor blades disposed at least partially beneath the disk. The rotor blades may be pivotable to provide for horizontal motion of the aircraft. 
   U.S. Pat. No. 5,595,358, issued Jan. 21, 1997, to Demidov et al., and titled MULTIPURPOSE AIRBORNE VEHICLE, describes an aircraft having a plurality of rotor units disposed below a ring-shaped fuselage. 
   U.S. Pat. No. 5,839,691, issued Nov. 24, 1998, to Lariviere, and titled VERTICAL TAKEOFF AND LANDING AIRCRAFT, describes such an aircraft that is clearly not symmetrical about its vertical axis. 
   U.S. Pat. No. 6,293,491, issued Sep. 25, 2001, to Wobben, and titled VERTICAL TAKE-OFF AND LANDING AIRCRAFT, describes another such aircraft that is clearly not symmetrical about its vertical axis. 
   Accordingly, it is a principal object of the present invention to provide a vertical takeoff aircraft that is aerodynamically stable. 
   It is a further object of the invention to provide such an aircraft that has high lift. 
   It is another object of the invention to provide such an aircraft that is highly symmetrical. 
   It is an additional object of the invention to provide novel landing gears, including ball wheels, for such an aircraft. 
   It is yet a further object of the invention to provide a novel method of adjusting pitches of rotating blades for such an aircraft. 
   Other objects of the present invention, as well as particular features, elements, and advantages thereof, will be elucidated in, or be apparent from, the following description and the accompanying drawing figures. 
   SUMMARY OF THE INVENTION 
   The present invention achieves the above objects, among others, by providing in a preferred embodiment, an apparatus, comprising: an aircraft having rotatable blades; and said rotatable blades are movable between horizontal and vertical positions. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     Understanding of the present invention and the various aspects thereof will be facilitated by reference to the accompanying drawing figures, provided for purposes of illustration only and not intended to define the scope of the invention, on which: 
       FIG. 1  is an isometric view of one embodiment of an aircraft according to the present invention. 
       FIG. 2  is a side elevational view of the embodiment of  FIG. 1 . 
       FIG. 3  is a fragmentary, isometric view of an alternative embodiment of the top mast of the aircraft. 
       FIG. 4  is a fragmentary, side elevational view of the alternative embodiment of  FIG. 3 . 
       FIG. 5  is a fragmentary, isometric view of an alternative embodiment of the covering of the upper part of the aircraft. 
       FIG. 6  is a side elevational view of the embodiment of  FIG. 1  with jet engines disposed on the wings of the aircraft. 
       FIG. 7  is a bottom plan view of the embodiment of  FIG. 6 . 
       FIG. 8  is a top plan view of the embodiments of  FIGS. 3 ,  4 , and  6 . 
       FIG. 9  is a side elevational, schematic view showing certain major elements of the aircraft of the present invention. 
       FIG. 10  is a fragmentary, isometric view showing a detail of the columns of the aircraft. 
       FIG. 11  is an isometric view of the aircraft with the landing gears thereof extended. 
       FIG. 12  is a fragmentary isometric view showing in more detail the mechanism of the landing gears of  FIG. 11 . 
       FIG. 13  is a top plan view of the locking mechanism of the landing gear of the aircraft, in unlocked position, but being locked. 
       FIG. 14  is a top plan view of the locking mechanism of the landing gear of the aircraft in locked position. 
       FIG. 15  is a partially exploded isometric view of a ball wheel with, inter alia, a drive shaft tube, a fixed axle, and drive gears. 
       FIG. 16  is a partially exploded view of the elements in partially assembled relationship. 
       FIG. 17  is an exploded isometric view of the major components of the ball wheel assembly. 
       FIG. 18  is an end elevational view, partially in cross-section, of some of the components of the ball wheel assembly in assembled relationship. 
       FIG. 19  is a fragmentary top elevational view, partially in cross-section, taken along line “ 19 - 19 ” of  FIG. 18 . 
       FIG. 20  is a fragmentary top elevational view, partially in cross-section, taken along line “ 20 - 20 ” of  FIG. 18 . 
       FIG. 21  is an isometric view showing some of the major elements of the propeller raising and lowering mechanism. 
       FIG. 22  is a fragmentary side elevational view showing, inter alia, the elements of  FIG. 21  installed in a column of the aircraft, two of the blades of the rotor in a raised or operating position. 
       FIG. 23  is a fragmentary isometric view showing a portion of a ball chain. 
       FIG. 24  is a fragmentary side elevational view showing a portion of a ball chain disposed over a ball chain engaging gear/pulley. 
       FIG. 25  is an isometric view of a gear/pulley for engaging a single ball chain. 
       FIG. 26  is an isometric view of a gear/pulley for engaging two ball chains. 
       FIG. 27  is a fragmentary side elevational view showing, inter alia, the elements of  FIG. 21  installed in a column of the aircraft, with two of the blades of the rotor in a lowered position. 
       FIG. 28  is a fragmentary side elevational view showing how the ball chains are used to adjust the pitch of the distal ends of two of the blades, the blades being shown in their raised position. 
       FIG. 29  is a fragmentary isometric view showing the routing of the ball chains to adjust the pitch of the distal ends of the blades using the ball chains. 
       FIG. 30  is a fragmentary isometric view showing the routing of the ball chains to adjust the pitch of the distal ends of the blades using miter gears. 
       FIG. 31  is a fragmentary side elevational view of an alternative embodiment of the routing of a chain  860 . 
       FIG. 32  is a fragmentary top plan view of the embodiment of  FIG. 31 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference should now be made to the drawing figures on which similar or identical elements are given consistent identifying numerals throughout the various figures thereof, and on which parenthetical references to figure numbers, when used, direct the reader to the view(s) on which the element(s) being described is (are) best seen, although the element(s) may be seen on other figures also. 
     FIGS. 1 and 2  illustrate an aircraft, constructed according to the present invention, and generally indicated by the reference numeral  100 . Aircraft  100  includes a transparent dome  110  near the top thereof, the dome being provided as a shield for the pilot of the aircraft. Aircraft  100  includes a centrally disposed upper portion  120  comprising an inverted hemisphere covered with a plurality of Z-shaped, overlapping zig-zag tiles, as at  122 . A plurality of windows, as at  130 , is disposed at the lower edge of the upper portion  120  and a plurality of lights, as at  132 , is disposed in an inverted truncated conical transitional portion  140  connecting the upper portion to a generally cylindrical lower portion  142 . The diameter of the upper end of generally cylindrical lower portion  142  is slightly greater than the diameter of the lower end thereof, while the diameter of the upper end thereof is less than the diameter of the lower end of the upper portion  120 . A horizontal air intake  144  for a rocket motor (not shown) disposed in generally cylindrical lower portion  142  is disposed at the intersection of the transitional portion  140  and the lower end of upper portion  120 . 
   Aircraft  100  includes four vertical columns  150  attached to lower portion  142  by four wings  152  and connected to transitional portion  140  by four support struts  154  (only three visible on  FIGS. 1 and 2 ). Sixteen generally horizontal blades, as at  160 , operatively connected to turboprop engines (not shown), four in each column  150 , are disposed near the top of the columns. Of course, other than turboprop engines may be provided as well. Each wing  152  contains an elevator  170  (only three visible on  FIG. 1  and only two visible on  FIG. 2 ). 
   Generally cylindrical lower portion  142  includes four radiator grills, as at  180  (only one shown on  FIG. 1  and none visible on  FIG. 2 ), the radiators being disposed for engine cooling. 
   At the base of each vertical column  150  is a support pad  190  (only three visible on  FIGS. 1 and 2 ) on which aircraft  100  generally is disposed. On each vertical column  150  is disposed an outwardly facing landing gear  200  (only three visible on  FIGS. 1 and 2 ) strapped to its respective vertical column by means of straps, as at  202 . The construction and operation of landing gears  200  is described in more detail, infra. 
   A vertical top mast centrally disposed atop and rising vertically from transparent dome  110  on upper portion  120  includes at the distal end thereof a shock ring  210 , a smooth primary sphere  212  underneath the shock ring, and a fluted secondary sphere  214  underneath the primary sphere. 
     FIGS. 3 and 4  illustrate an alternative embodiment of the vertical top mast and includes a vertical pointed spike  250  at the top thereof, underneath which is a first spherical globe  252 , underneath which is a second spherical globe  254  having a diameter greater than that of the first spherical globe, and underneath the second spherical globe is a third spherical globe  256  having a diameter greater that that of the second spherical globe. 
     FIG. 5  illustrates an alternative covering for upper portion  120 , here a plurality of rosettes, as at  260 , each disposed on a tile, as at  262 . 
     FIG. 6  illustrates pairs of vertically disposed jet engines  280  on each of wings  152  (only four shown on  FIG. 6 ). 
     FIG. 7  illustrates a bottom plan view of the embodiment of  FIG. 6  and also shows extending downwardly from a lower surface of generally cylindrical lower portion  142  four outlet nozzles  300  of the rocket engine (not shown) disposed in lower portion  142 . 
     FIG. 8  illustrates a top plan view of the embodiment of  FIGS. 3 ,  4 , or  6 , without the covering of top portion  120 . 
     FIG. 9  illustrates schematically the engines  320 , the generators  330  operatively connected to the engines, and fuel tanks  350 ,  352 , and  354 . Fuel tanks  350  may supply fuel to engines  320 , fuel tank  352  may supply fuel to the rocket engine (not shown), and fuel tanks  354  may supply fuel to jet engines  280  ( FIG. 6 ). Generators  330  may supply power to power-consuming elements of aircraft  100 . 
   The arrows on  FIG. 9  illustrate the symmetrical flow of air past aircraft  100  when the aircraft is in flight caused by the symmetry of aircraft  100 . The shape of the fuselage of aircraft  100  also contributes to high lift. 
     FIG. 10  illustrates that columns  150  ( FIG. 1 ) may have vertical flutes, as at  380 . 
     FIGS. 1-10  illustrate aircraft  100  in position for takeoff, or shortly after takeoff. At takeoff, aircraft  100  rests on support pads  190  ( FIG. 1 ) which are disposed on a generally horizontal surface (not shown). At takeoff, horizontal blades  160  are rotating and are adjusted to their maximum pitches. The rocket engine (nozzles  300  shown on  FIG. 7 ) is ignited. If jet engines  280  ( FIG. 6 ) are used, they have been ignited. The thrust thus developed by the various engines causes aircraft  100  to take off. 
     FIG. 11  illustrates landing gears  200  deployed for maneuvering aircraft  100  on a surface (not shown). 
     FIG. 12  illustrates in more detail the construction of a deployed landing gear  200 . Landing gear  200  includes a generally vertical outer housing  400  that is strapped to a column  150  with a plurality of straps, as at  202 . A support/drive housing  410  closes generally vertical outer housing  400  when the support/drive housing is in a retracted position ( FIG. 1 ). It will be understood that a ball wheel  420  disposed at the distal end of support/drive housing  410  is below support pad  190  when the support/drive housing  410  is in the extended position shown. 
   Internally of generally vertical outer housing  400  are fixedly mounted two hydraulic motors  430  that are operatively connected to a horizontal shaft  432  on which is mounted two vertical drive pulleys  434 . Drive pulleys  434  drive vertical two endless belts (or chains)  440  that are looped around at their bottoms two idler pulleys  442  fixedly disposed with respect to horizontal shaft  432 . A plate  450  is fixedly attached to two vertical belts  440  such that the plate rides up and down in generally vertical outer housing  400 . Rotatably attached to plate  450  and to support/drive housing  410  is a retraction/support strut  460 . It will be understood that, as plate  460  is lowered in generally vertical outer housing  400 , support/drive housing  410  will be extended as shown on  FIG. 12 , and, as plate  460  is raised in the generally vertical outer housing, the support/drive housing will be retracted to its closed position ( FIG. 1 ). 
   Ball wheel  420  is disposed in ball drive assembly  480  and disposed atop the ball wheel, as shown on  FIG. 12 , is locking member  500 , the structure and function of these elements being described in detail, infra. 
     FIG. 13  illustrates support/drive housing  410  being locked in retracted position. Two hydraulic cylinders  510  are fixedly mounted in column  150 . Two catches  520  are fixedly disposed at the ends of two pistons  522  movable within the hydraulic cylinders, the catches being disposed so as to lock locking member  500  in place in column  150  as the catches are moved in the direction indicated by the arrows on  FIG. 13 . 
   On  FIG. 14 , catches  520  have fully engaged locking member  500  and support/drive housing  410  securely closes generally vertical outer housing  400 . 
     FIG. 15  illustrates ball wheel  420  with a fixed axle  540  that is inserted through the ball wheel and a drive shaft tube  550  that fits rotatingly over the fixed axle. First and second drive gears  560  and  562 , respectively, are fixedly disposed at the ends of drive shaft tube and a counter gear  564  drives second drive gear  562 . As will be seen, infra, this arrangement permits first and second drive gears  560  and  562  to be driven by a ring gear (not shown on  FIG. 15 ). A bracket  570  is provided to hold counter gear  564 . Ball wheel hubs  580  are fixedly disposed on either side of ball wheel  420  through which fixed axle  540  and drive shaft tube  550  pass. 
     FIG. 16  illustrates the elements of  FIG. 15  in partially assembled relationship. 
     FIG. 17  is an exploded isometric view of the major elements of ball drive assembly  480 . Starting at the top and working downwardly, first there is the locking member  500 , then a top ball wheel cover  600 , then a top gasket  602 , then a ball housing cover  604 , then a cover member  606 , with four circumferentially equally spaced vertical slots formed on the outer periphery of the cover member, and then a first bearing ring  610 . First bearing ring  610  includes (not shown in detail) top and bottom bearing races between which is disposed a plurality of needle bearings. Subsequent bearing rings have a similar same structure. 
   Continuing to refer to  FIG. 17 , next, there is a drive gear ring  620  (shown on  FIG. 17  inverted for clarity), with teeth formed on its outer periphery and on its lower inside surface, followed by a second bearing ring  622 , and then ball wheel  420 . Next, is a ball wheel housing mid-section  630 , with seven upper idler gears  632  vertically disposed in an upper portion thereof, and with four circumferentially equally spaced vertical slots  634  formed on the outer periphery of the ball wheel housing mid-section. Also shown with ball wheel housing mid-section  630  is a ball wheel steering motor and gearing  636 , with the latter portion of that element extending into the interior of the ball wheel housing mid-section to engage teeth of a ball wheel steering gear. Also shown with ball wheel housing mid-section  630  is a ball wheel drive motor and gearing  638 , with the latter portion of that element extending into the interior of the ball wheel housing mid-section to engage the gear teeth formed on the outer periphery of drive gear ring  620 . 
   Then, there is a third bearing ring  640 , followed by a steering gear ring  642 , with two holes  643  (only one visible on  FIG. 17 ) for the journaling therein of fixed axle  540  and with teeth formed on its outer periphery, and then a fourth bearing ring  644 . Next, there is a ball wheel housing base  650 , with seven vertically disposed idler gears  652  rising from an upper surface of the ball wheel housing base, and with four circumferentially equally spaced slots  654  formed on the outer periphery of the ball wheel housing base. 
   Next, there is a ball wheel bearing housing  660  into the circular portion of which are disposed the above elements beginning with cover member  606 . Four vertical flanges are formed on the interior periphery of the circular portion of ball wheel housing  660  to engage slots  608 ,  634 , and  654  to keep the respective elements of which the slots are a part from rotating with respect to the wheel bearing housing. Also shown as part of ball wheel housing  660  are cutouts  680  and  682  to accommodate, respectively, steering motor and gearing  636  and drive motor and gearing  638 . Finally, there is a bottom gasket  690 . 
     FIG. 18  illustrates some of the major elements of wheel drive assembly  480  in assembled relationship. A description of these elements of ball drive assembly  480  is given with reference to  FIG. 17 . In addition, bearing balls, as at  700 , are disposed between ball wheel  420  and ball wheel cover  602  to bear some of the load presented by the ball wheel. 
     FIG. 19  illustrates some of the major elements of ball wheel drive assembly  480  in assembled relationship. A description of these elements of ball drive assembly  480  is given with reference to  FIG. 17 . 
     FIG. 20  illustrates some of the major elements of ball wheel drive assembly  480  in assembled relationship. A description of these elements of ball drive assembly  480  is given with reference to  FIG. 17 . 
     FIG. 21  illustrates some of the major elements of the mechanism to raise and lower blades  160  ( FIG. 1 ). At the heart of the mechanism is a vertical splined core  800  that, at its bottom, fits adjacent a clamp cap base  802 . A tooth ring  810  having complementarily shaped teeth on its inner periphery fits over splined core  800  and a spacer ring  812  also having complementarily shaped teeth on its inner periphery fits over the splined core and engages and separates adjacent tooth rings  810 . 
     FIG. 22  illustrates the elements of  FIG. 21  installed in a column  150 . Blades  160  have been raised to their operating position by the piston  820  of a stationary hydraulic cylinder  822  lowering splined core  800 , as is indicated by the arrows on  FIG. 22 , and a tooth ring  810  engaging uppermost indentations  830  in the proximal ends of blades  160 . It will be understood that a second pair of blades  160  (not shown on  FIG. 22 ) will be disposed orthogonal to the blades shown on  FIG. 22 . Rotational motion is imparted to the assembly by means of a rotating shaft  840  operatively connected to a motor  320  ( FIG. 9 ). A short spacer ring  842  is disposed at the top of splined core  800  and a long spacer ring  844  is disposed at the bottom of the splined core. 
   Also shown as rotating elements on  FIG. 22  are a vertical housing  850 , a truncated cone  852 , to compress incoming air, attached to the top of the vertical housing, four counterbalance balls  854  (only two shown on  FIG. 22 ) fixedly attached to the housing, pins  856  to attach all the spacers to splined core  800 , and ball chains  860 , the function of which is described, infra. 
   Non-rotating elements shown on  FIG. 22 , in addition to piston  820  and hydraulic cylinder  822 , include column  150 , supporting strut  154 , and a bull nose  870 . 
     FIG. 23  illustrates a ball chain  860  comprises a plurality of balls, as at  900 , adjacent pairs of which are held together by pins, as at  902 , having enlarged heads (not shown) at either end thereof. Ball chain  860  is highly flexible and strong. 
     FIG. 24  illustrates ball chain  860  being engaged by a circular gear/pulley  910 . Gear/pulley  910  has a plurality of teeth, as at  920 , equidistantly spaced about the outer periphery of the gear/pulley, adjacent pairs of which teeth about the outer periphery of the gear/pulley engage one of the balls  900  of ball chain  860 . Gear/pulley  910  may drive ball chain  860  or it may be an idler gear/pulley. 
     FIG. 25  illustrates a gear/pulley  930  for engaging a single ball chain  860 . It will be noticed that teeth  920  are disposed in side-by-side pairs, with each pair of teeth lying in a plane parallel to the central plane of gear/pulley  930 . 
     FIG. 26  illustrates a gear/pulley  940  for engaging two ball chains  860 . It will be noticed that teeth  920  are disposed side-by-side three abreast, with each triplet of teeth lying in a plane parallel to the central plane of gear/pulley  940 . 
     FIG. 27  illustrates blades  160  in a lowered position, the blades having been brought to this position by the raising of splined core  800 , in the direction of the arrow on  FIG. 27 , such that the lower of tooth rings  810  engages the lower of indentations  830  on the proximal ends of the blades. This is the position blades  160  assume when aircraft  100  ( FIG. 1 ) has reached a certain speed. Of course, motor  320  ( FIG. 9 ) would be shut off when blades  160  are lowered. 
     FIG. 28  illustrates how ball chains  860  are used to adjust the pitch of the distal ends of opposing blades  160 . Note that gear/pulley  1000  is driven by a hydraulic motor (not shown). The rest of the gear/pulleys are idlers. The opposite side is a mirror image of the side shown, including a hydraulic drive motor synchronized to the hydraulic motor driving gear/pulley  1000 . It will be understood that a second pair of drivers similar to that shown will be employed to adjust the distal ends of a pair of blades  160  orthogonal to those shown. 
     FIG. 29  illustrates the routing of ball chains  860  to adjust the pitches of the distal ends of blades  160  using the ball chains. Note that there are four motorized gear pulleys  1010  (only three visible on  FIG. 29 ) that drive the ball chains  860 . The rest of the gear/pulleys are idlers. For greater clarity, the teeth on the gear/pulleys have been omitted. 
     FIG. 30  illustrates the routing of ball chains  860  to adjust the pitch of the distal ends of blades  160  using miter gears. Again, there are only four motorized gear/pulleys that drive ball chains  860 , the rest of the gear/pulleys being idlers. Again, for greater clarity, the teeth on the gear/pulleys have been omitted. 
     FIG. 31  illustrates an alternative embodiment of the routing of ball chain  860 . Again, only gear/pulley  1020  is motorized. 
     FIG. 32  is another view of the alternative embodiment of  FIG. 31 . 
   It should be noted that the embodiment of  FIGS. 22-30  has four ball chains  860  per side for a total of sixteen chains, while the embodiment of  FIGS. 31 and 32  has only one ball chain per side for a total of four chains. 
   In the embodiments of the present invention described above, it will be recognized that individual elements and/or features thereof are not necessarily limited to a particular embodiment but, where applicable, are interchangeable and can be used in any selected embodiment even though such may not be specifically shown. 
   Spatially orienting terms such as “above”, “below”, “upper”, “lower”, “inner”, “outer”, “inwardly”, “outwardly”, “vertical”, “horizontal”, and the like, when used herein, refer to the positions of the respective elements shown on the accompanying drawing figures and the present invention is not necessarily limited to such positions. 
   It will thus be seen that the objects set forth above, among those elucidated in, or made apparent from, the preceding description, are efficiently attained and, since certain changes may be made in the above construction without departing from the scope of the invention, it is intended that all matter contained in the above description or shown on the accompanying drawing figures shall be interpreted as illustrative only and not in a limiting sense. 
   It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.