Abstract:
A spiral mass launcher for moving a mass including a spindle support assembly; connected to a swing-arm pair module. The spindle support assembly rotates on a motor shaft, allowing the swing-arm pair module to swing on a parallel bearing shaft. A spiral track passes through a radial opening in the bearing shaft. Thus, the swinging motion of the swing-arm pair modules allows the spiral track to move in a gyrating motion. The spiral track has a first end and a second end, the first end adapted to receive a mass or projectile and a second end adapted to launch the mass. A mass can be fed into the spiral mass launcher by either a feed mechanism that feeds the mass into the first end of the spiral. Such feed mechanisms include a feed mechanism that linearly oscillates and picks up the mass at a first amplitude of oscillation and feeds the mass into the first end of the spiral track at a second amplitude of oscillation; or a feed mechanism that includes a continuous tube and “crank arm” feed. The mass can also be fed into the spiral track by a low jitter gun.

Description:
RELATED APPLICATIONS  
       [0001]    This application relates to U.S. application Ser. No. 10/091,025 now U.S. Pat. No. 6,712,055, filed on Mar. 6, 2002, which claims priority to U.S. Provisional Patent Application Number 60/273,640, filed on Mar. 7, 2001, which are both incorporated herein by reference in their entirety. This application also claims priority to U.S. Provisional Patent Application No. 60/467,551, which is incorporated herein by reference in its entirety. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to a device that moves a mass, and more particularly, to an apparatus with a spiral or arcuate track that launches a mass. The present invention may be used to launch objects into space.  
           [0004]    2. Description of the Related Art  
           [0005]    Mass launchers are generally known. Some examples include U.S. Pat. No. 5,699,779 to Tidman, entitled “Method of and Apparatus for Moving a Mass,” U.S. Pat. No. 5,950,608 to Tidman, entitled, “Method of and Apparatus for Moving a Mass,” and U.S. Pat. No. 6,014,964 to Tidman, entitled, “Method and Apparatus for Moving a Mass in a Spiral Track,” all of which are herein incorporated by reference in their entirety.  
           [0006]    While earlier mass launchers were serviceable, they did not permit higher gyration speeds because of structural shortcomings. For example, previous designs would have difficulty achieving higher gyration speeds because they would not be able to safely handle the forces imposed by those higher rotational rates.  
           [0007]    Another problem facing previous designs is the aerodynamic or fluid dynamic drag. As the spiral track is gyrated at higher and higher speeds, drag would impose greater and greater loads on many of the components of the spiral mass launcher. Another problem facing spiral mass launchers is the lack of an adequate feed mechanism. One theoretical advantage of spiral mass launchers is their ability to provide a high rate of fire. However, previous designs could not achieve this advantage due to a lack of a suitable feed mechanism that would be able to deliver masses or projectiles into the mass launcher at requisite rates.  
           [0008]    In adapting mass launchers to specific applications, those skilled in the art are continually in search of designs that are easy to fabricate and that reduce the loads on the individual components of the mass launchers to therefore increase service life.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention relates to mass launchers. More specifically, the present invention is directed to a mass launcher having a spiral or arcuate track. The mass launcher of the present invention includes an arm pair module comprised of a spindle support assembly, swing arms, and a launch ring pivot bearing assembly. The spindle support assembly is connected to the launch ring pivot bearing assembly through the swing arms. The swing arm pair module includes an upper arm and a lower arm. The upper arm has a first end and a second end, the first end is pivotally connected to the spindle support assembly, and the second end has a first cup. The lower arm has a first end and a second end, the first end is pivotally connected to the spindle support assembly, and the second end has a second cup. A vertically stacked or radially nested bearing and bearing shaft are disposed within the first and second cups. The bearing shaft includes a radial opening along its longitudinal length so that an arcuate launch tube can pass therethrough. The present invention also includes one or more embodiments as discussed below.  
           [0010]    In one embodiment of the present invention, there are a plurality of adjacent arm pair modules. Each of the bearing shafts has a radial opening therethrough so that the launch tube can pass through one bearing shaft to another bearing shaft in the adjacent arm pair module. This configuration eliminates the need for an attachment plate between the tube and a swing arm, and therefore reduces the swinging mass.  
           [0011]    In another embodiment of the present invention, the swing arms are flat horizontally arranged arms which allow for easy construction of the mass launcher.  
           [0012]    In another embodiment of the present invention, the cups are vertically arranged at the second end of the upper and lower swing arms, to house the bearings around the bearing shaft. For example, in one embodiment, two stacked bearings are provided in each of the upper and lower swing arms. This configuration shares the load carried per bearing at the end of the arm.  
           [0013]    In another embodiment of the present invention, concentrically nested bearings allow bearings with a higher rated load to be used while providing a sufficient total speed f 1 +f 2  since the inner bearing turns inside the outer bearing.  
           [0014]    Enabled by the above design embodiments, a relatively larger diameter launch tube is formed to allow the launching of larger mass projectiles. The above embodiments provide bearing assemblies with relatively long life spans and a relatively stiff launch tube span located between adjacent swing arm pair modules.  
           [0015]    In another embodiment of the present invention, the mass or projectile is fed into the launch tube using unique projectile-feed approaches such as a low jitter gun, an oscillating feed block, or a centrifugal feed system.  
           [0016]    Another embodiment of the present invention includes a phase swing launch method in which a “soft elastic collision” occurs between a projectile traveling in the spiral launch tube and a track displacement wave traveling at high speed around the spiral launch tube. The projectile executes a swing in phase relative to the traveling wave as the projectile accelerates and is thrown forward. The phase swing approach is used to reduce the size of both the ring and spiral mass launcher accelerators.  
           [0017]    Another embodiment of the present invention includes a multi-turn spiral launch tube with close turns to approximate a ring that launches a stream of projectiles at a relatively high velocity.  
           [0018]    Additional aspects, features, and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The aspects, features, and advantages of the invention will be realized and attained by the structure and steps particularly pointed out in the written description, the claims, and the drawings.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0019]    [0019]FIG. 1 is an isometric diagram of a portion of an exemplary spiral mass launcher having a launch tube mounted through an opening in a bearing shaft, according to an embodiment of the present invention;  
         [0020]    [0020]FIG. 2 is a schematic diagram of a cross-sectional side view of an exemplary swing-arm pair module showing a launch tube passing through a bearing shaft, according to an embodiment of the present invention;  
         [0021]    [0021]FIGS. 3A and 3B are schematic diagrams of cross-sectional side views of a launch tube passing through an exemplary bearing shaft, according to an embodiment of the present invention;  
         [0022]    [0022]FIG. 4A is a schematic diagram of a top view of an exemplary swing-arm, according to an embodiment of the present invention;  
         [0023]    [0023]FIG. 4B is a schematic diagram of a side view of an exemplary swing-arm pair module, according to an embodiment of the present invention;  
         [0024]    [0024]FIG. 5A is an isometric diagram of a ring bearing;  
         [0025]    [0025]FIG. 5B is a schematic diagram of a ring bearing having a stationary ring with a shaft spinning at frequency f 1 ;  
         [0026]    [0026]FIG. 5C is a schematic diagram of a ring bearing having a ring spinning at frequency f 2  and a shaft spinning at frequency f 1 +f 2 ;  
         [0027]    [0027]FIG. 5D is a schematic diagram of an exemplary nested bearing, according to an embodiment of the present invention;  
         [0028]    [0028]FIG. 6 is a schematic diagram of an exemplary two-turn system, according to an embodiment of the present invention;  
         [0029]    [0029]FIG. 7 is a schematic diagram of an exemplary linearly oscillating projectile feed block, according to an embodiment of the present invention;  
         [0030]    [0030]FIGS. 8A-8F are isometric diagrams illustrating an exemplary operation of the feed block of FIG. 7, according to an embodiment of the present invention;  
         [0031]    [0031]FIG. 9 is an isometric diagram of an exemplary gun injection feed system, according to an embodiment of the present invention; and  
         [0032]    [0032]FIG. 10 is schematic diagram of an exemplary centrifugal feed system, according to an embodiment of the present invention. 
     
    
       [0033]    Exhibit 1 is an article titled “Constant-Frequency Hypervelocity Slings,” by D. A. Tidman, which describes further aspects and details of the present invention.  
         [0034]    Exhibit 2 is a list of publications providing background for the subject matter of the present invention.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0035]    [0035]FIGS. 1-10 illustrate embodiments of the mass launcher of the present invention.  
         [0036]    [0036]FIG. 1 illustrates a portion of an exemplary spiral mass launcher. A spiral mass launcher of the present invention preferably comprises a track with a hollow or U-shaped channel and includes openings or access points at both ends for a mass or projectile to enter and exit the track. The projectile enters the track at a first end and exits through a second end. As the mass launcher gyrates, relative to the ground, the projectile is subjected to various forces and the motion of the mass launcher tends to move the projectile around the track toward the second end.  
         [0037]    The mass launcher of the present invention includes a spindle support assembly  2  including an upper swing arm  4  having a first end  6  and a second end  8 , and a lower swing arm  14  having a first end  16  and a second end  18 . The first end  6  of the upper swing arm  4  is pivotally connected to the spindle support assembly  2 . Counterweights  36  are provided at the second end  8  and  18  of each swing arm  4  and  14 . The second end  8  of the upper swing arm  4  includes a first cup  10 . The first end  16  of the lower swing arm  14  is pivotally connected to the spindle support assembly  2 . The second end  18  of the lower swing arm  14  has a second cup  20 . A bearing shaft  12  is disposed within the first cup  10  and the second cup  20 .  
         [0038]    The bearing shaft  12  is connected to the upper  4  and lower  14  swing arms, which are swingably fixed to the spindle support assembly  2 . In one embodiment, two needle bearing  26  are stacked in each swing arm  4  and  14 , respectively, providing four needle bearings in each arm-pair module, which is also referred to as a launch ring pivot bearing assembly. See FIG. 2.  
         [0039]    The bearing shaft  12  is illustrated in FIGS. 2 and 3A as having a radial opening  22  in which a launch tube  24  is disposed.  
         [0040]    In one embodiment of the present invention, the launch tube  24  forms a spiral track as shown in FIG. 6 for example.  
         [0041]    [0041]FIG. 2 shows a cross-sectional side view of an exemplary swing-arm pair module showing the launch tube  24  passing through a bearing shaft  12 , according to an embodiment of the present invention. This cross-sectional view shows two needle bearings  26  stacked in each swing arm  4 ,  14 . FIG. 3A shows the bearing shaft  12  disposed inside of the needle bearing  26 . The spindle support assembly  2  also includes a plurality of tapered roller bearings  32  disposed on the outer surface of a motor shaft  40 . The motor shaft  40  is operatively connected to a motor  38 , which turns the shaft  40  for rotating the spindle support assembly  2 .  
         [0042]    [0042]FIG. 2 illustrates an exemplary swing arm module and launch track enclosed in a housing  28  to reduce drag on the individual components of the swing-arm pair module.  
         [0043]    [0043]FIGS. 3A and 3B show cross-sectional side views of a launch tube  24  passing through the opening  22  of the exemplary bearing shaft  12 , according to an embodiment of the present invention. The launch tube  24  also has a plurality of venting slots  42  extending along the length of the tube. The venting slots  42  permit the escape of air, thus reducing air drag and resistance on the projectile. Preferably, the slots  42  are formed on the inner curve of the track. In other words, slots  42  are disposed in a region away from the path of contact between the projectile and the track. The launch tube  24  is formed from a material having a low friction coefficient, such as, for example, steel.  
         [0044]    The needle bearings  26  in the cups  10 ,  20  rotate along the outer surface of the bearing shaft  12 , between the bearing shaft  12  and the inner surfaces of the first and second cups,  10 ,  20 , respectively. Thrust bearings  44  are disposed on a shoulder portion of the bearing shaft  12  to retain the bearing shaft  12  in a stable position with respect to the cups  10 ,  20 , and also reduce friction between the shoulder portion of the bearing shaft  12  and the washer  46 . The bearing shaft  12  is also formed from a material having a low friction coefficient, such as, for example, steel.  
         [0045]    [0045]FIG. 4A illustrates a top view of an exemplary swing-arm, according to an embodiment of the present invention. FIG. 4B shows a side view of an exemplary swing-arm pair module, according to an embodiment of the present invention. Each swing arm  4 ,  14  is flat and disposed horizontally relative to the ground to allow for easy construction of the launcher. The first end  6 ,  16  of swing arm  4 ,  14  includes an aperture  58  to receive the motor shaft  40 . The second end  8 ,  18  of the swing arm  4 ,  14  includes an aperture  30  for inserting the bearing shaft  12 . The swing arm  4 ,  14  also includes a center aperture  56  to reduce the weight of the arm. The swing arms  4 ,  14  and spindle support assembly  2  can be made from steel, or a lighter weight material such as titanium alloy.  
         [0046]    [0046]FIG. 5A illustrates a ring of needle bearings, or ring bearing  26 . FIG. 5B shows the ring bearing having a stationary ring  26   a  with a bearing shaft  12  disposed therein. The bearing shaft  12  spins at frequency f 1 . FIG. 5C shows a ring bearing having a ring  26   a  spinning at frequency f 2  and a bearing shaft  12  disposed in the ring  26   a  spinning at frequency f 1 +f 2 . FIG. 5D illustrates an exemplary nested bearing, according to an embodiment of the present invention. In the nested bearing of FIG. 5D, the ring  26   b  of the outer bearing is stationary and the outer bearing encloses the inner spinning bearing. The radial nesting of the bearings for large rated loads and high gyrations allow the swing arm module to have a larger diameter shaft resulting in less flexure for load sharing.  
         [0047]    The present invention contemplates at least two ways to increase the load capacity of bearings at the end of a swing arm of given swing radius r. One method is to vertically stack bearings  26  in the upper  4  and lower  14  arms as shown, for example, in FIGS. 2 and 3A. A second method of increasing the bearing load capacity is to radially or concentrically nest two bearings as shown in FIG. 5D. In a further embodiment, both of these methods are used.  
         [0048]    Typically, as the radius of the bearing (r brg ) shown in FIG. 5B, and axial length of a bearing of fixed design shown in FIG. 5A, increases, the rated load of the bearing increases as r brg   2 , and the maximum speed of the bearing in revolutions per minute decreases at a rate equal to the inverse of the bearing radius, or 1/r brg . If a sufficiently large bearing  26   a  is chosen to satisfy a desired rated load L 1 , but has a maximum speed of f 1  that is too small, then the bearing  26   a  should be enclosed in an even larger bearing  26   b  so that the outer race of bearing  26   a  spins inside bearing  26   b  with a maximum speed of f 2 . See FIGS. 5B-5D. This provides the desired shaft speed f 1 +f 2  without reducing the desired rated load L 1 . However, the rated load L 2  of the larger outer bearing  26   b  must then suffice for both the original shaft load plus the additional load due to the mass of the inner bearing, i.e., in this case:  
           L   2     &gt;       L   1     +       m   1          (       v   2     r     )           ,                         
 
         [0049]    where m 1 , is the mass of the inner bearing.  
         [0050]    Those skilled in the art of bearing design would appreciate how to optimize the gain from this combination.  
         [0051]    Thus, the present invention provides multiple ways by which to increase the rated load for high speed, namely by vertical stacking, by radial nesting, or by a combination thereof.  
         [0052]    As shown in FIG. 5D, the center ring  26   a  (between the bearing shaft  12  and the outermost ring  26   b ) is located (floats) between two rings of rollers. If the bearing shaft  12  is powered up to speed, and the outermost ring is anchored to be stationary, rolling friction between the bearing shaft  12  and outer ring  26   b  will spin the center ring. The rollers adjacent to the shaft accelerate the center ring, and the rollers in the outer bearing  26   b  will decelerate the center ring. The center ring is rapidly brought up to a speed for which these two rolling friction forces come into equilibrium, which occurs very rapidly when the load forces are large. Analysis shows that the center ring reaches a speed between the surface speed of the shaft and zero, and this equilibrium speed is a function of roller radii (assuming all rollers and races have the same surface quality).  
         [0053]    [0053]FIG. 6 illustrates an exemplary two-turn system, according to an embodiment of the present invention. In this embodiment, a plurality of electric motors  38  is distributed around the system, such that one electric motor  38  provides power to more than one swing arm module. For example, it is envisioned that a single motor  38  provide power to three or four swing-arm pair modules. As such, the cost of manufacturing the spiral mass launcher can be reduced. The number of motors per swing-arm pair module depends upon how much power is needed to swing the arms. Few relatively large motors are able to provide the same power as smaller motors for each swing-arm pair module because with the larger motors, the swing-arm pair modules are locked together due to the rigidity of the tube. Therefore, the arms swing at the same rate.  
         [0054]    There are several ways to feed a series of projectiles into an gyrating spiral tube. For example, FIG. 7 illustrates an exemplary linearly oscillating projectile feed block, according to an embodiment of the present invention. FIGS. 8A-8F illustrate an exemplary operation of the feed block of FIG. 7, according to an embodiment of the present invention. As shown in these progressive schematics, the projectiles  50  are injected from a feed block  52  that linearly oscillates on rails  54  and matches speed and position with the feed block entrance  62  at the mid-point of the rails  54 . See FIGS. 8A and 8B. The feed block  52  briefly comes to rest at a maximum amplitude on the right side of the rails  54 , as illustrated in FIG. 8C, where the feed block  52  picks up a projectile  50  from the projectile feeder  60 , through which the projectiles  50  are fed to the feed block  52 . The projectile  50  is fed into the projectile entrance  62  of the feed block  52 . As illustrated in FIG. 7, for example, the projectiles are arranged as a belt and individually fed into the projectile feeder  60 .  
         [0055]    As shown in FIG. 8A, the projectiles  50  are transferred from the feed block  52  to the launch tube  24  when the feed block  52  contacts the launch tube during the feed block travel to the right at the midpoint of the rails  54 .  
         [0056]    Once the projectile  50  is fed into the feed block  52 , as illustrated in FIG. 8C, the center piston  66  then carries the injection block with a projectile  50  back along the rails  54 , as illustrated in FIG. 8D, after which, as illustrated in FIG. 8E, the feed block  52  returns to the left and then returns to the right, and passes through a center position very close to the launch tube entrance  64  with the same velocity as the entrance. The projectile  50  is then injected into the launch tube  24  during the close pass. See FIG. 8F.  
         [0057]    [0057]FIG. 9 illustrates an exemplary gun injection feed system, according to an embodiment of the present invention. The projectile  50  is injected into the spiral launch tube entrance  64  when the entrance to the tube is aligned with, and moving away from, the gun tube  34 . Projectiles are transferred from the feed block  52  to the launch tube  24  when the feed block is gently touching the launch tube during the feed block travel to the right at the midpoint of the rails.  
         [0058]    Another embodiment of the present invention includes a phase swing launch method in which a “soft elastic collision” occurs between a projectile  50  traveling in the spiral launch tube  24  and a track displacement wave traveling at high speed around the track. As such, the projectile  50  executes a swing in phase relative to the traveling wave as the projectile  50  accelerates and is thrown forward. The phase swing approach is used to reduce the size of both the ring and spiral mass launcher accelerators.  
         [0059]    [0059]FIG. 10 shows an exemplary centrifugal feed system, according to an embodiment of the present invention. In this system, a rotating feed tube  74  shaped like a “crank arm” extends perpendicular relative to the spiral plane of the launch tube  24 . The lower pivot  68  swings around the gyration circle and the upper pivot  70  is stationary relative thereto. A projectile  50  is propelled into the stationary feed inlet  72  and is accelerated by centripetal force to swing speed v as it moves out through the tube between the pivots  68 ,  70 . The projectile  50  then passes down into the spiral where the projectile is further accelerated. This has the advantage that the entrance tube  72  is stationary and connects continuously to the gyrating spiral launch tube  24 , but the feed involves a small radius of curvature tube that limits the projectile length.  
         [0060]    Further details and aspects of the present invention are described in the article included herein as Exhibit 1, entitled “Constant-Frequency Hypervelocity Slings.” The article of Exhibit 1 provides further explanations of FIGS. 1, 6,  7 ,  9 , and  10 . The article also provides additional descriptions and figures of embodiments of the present invention and is incorporated by reference herein in their entirety.  
         [0061]    In light of the above descriptions, a mass launcher according to the present invention can have one or more of the following characteristics: tube of constant wall thickness; rapid fire stream; hypervelocity; off-the-shelf components such as electric motors or turbines, and bearings; an inertial storage device in which projectiles passing through extract energy with no pulsed power train; and mechanical rolling and projectile sliding friction coefficients decrease with increasing size.  
         [0062]    Further background for the present invention is provided by the publications and patents listed in Exhibit 1, which are incorporated by reference herein in their entirety.  
         [0063]    The foregoing disclosure of the preferred embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many variations and modifications of the embodiments described herein will be obvious to one of ordinary skill in the art in light of the above disclosure. The scope of the invention is to be defined only by the claims appended hereto, and by their equivalents.  
         [0064]    Further, in describing representative embodiments of the present invention, the specification may have presented the method and/or process of the present invention as a particular sequence of steps. However, to the extent that the method or process does not rely on the particular order of steps set forth herein, the method or process should not be limited to the particular sequence of steps described. As one of ordinary skill in the art would appreciate, other sequences of steps may be possible. Therefore, the particular order of the steps set forth in the specification should not be construed as limitations on the claims. In addition, the claims directed to the method and/or process of the present invention should not be limited to the performance of their steps in the order written, and one skilled in the art can readily appreciate that the sequences may be varied and still remain within the spirit and scope of the present invention.