Abstract:
A sky diving training device for training a student to assume the correct position for free fall. The device has a platform mounted on a swivel. The student lies face down on the platform with his shoulders on a steering bar. When the student diver allows one shoulder to drop, the device begins rotating in a predetermined direction. When the student corrects his shoulder position, the device stops rotating, however if the student over corrects the shoulders, the device begins rotating in the opposite direction. The rotation simulates what happens in a free fall if the diver allows one shoulder to drop even slightly.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a sky diving training device which is used during the ground training of a new diver. 
     Sky diving is the term used for the sport of parachuting. The diver jumps from an airplane, experiences free fall for an approximate predetermined period of time and then opens his chute and somewhat slowly falls to the ground. When a potential diver is receiving his preliminary training on the ground before diving and between his first few dives, it is important that he be taught the correct body position to be maintained during the free fall part of the dive. This body position emulates lying on one&#39;s stomach with the arms extended overhead and the legs moderately spread apart. 
     During the free fall, the air velocity striking the free falling body, is approximately 130 miles per hour. If the diver allows one shoulder to drop below the level of the other shoulder, the air velocity causes the diver to rotate clockwise if the right shoulder drops or counterclockwise if the left shoulder drops. The rotation increases in speed without correction by the diver making it difficult to deploy the parachute. The device of the present invention teaches the diver to recognize the start of rotation of the body and how to instinctively correct it. 
     Devices to teach body response to external conditions have been developed. For example, U.S. Pat. No. 5,328,427 to R. Sleamaker provides a skating/skiing simulator with ergometric input-responsive resistance. U.S. Pat. No. 4,505,477 to J. Wilkinson provides a balancing board to teach the user to respond to changes of his footing while maintaining his balance. U.S. Pat. No. 5,545,115 to A. Corcoran provides a snowboard simulator apparatus to teach the skills required to snowboard. U.S. Pat. No. 5,895,340 to M. Keller provides a training device especially adapted for use in teaching techniques for snow boarding and skiing. None of these devices assists a sky diver in his endeavor to improve his skills for parachuting. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention provides a device suitable for teaching the skills required of a sky diver to prevent the diver from spinning uncontrollably during free fall. The sky diving training device is comprised of a base having a ring gear mounted thereon. A swivel is mounted to the ring gear, the axis of the swivel being directly above the axis of the ring gear. An elongated platform is mounted substantially centered on the swivel, the platform having attached thereto at one end a shoulder steering bar and at the opposite end of the platform an attached leg separation means. The shoulder steering bar pivots on a center allowing either end of the bar to be depressed downwardly so as to impact one of two switches placed under the ends of the steering bar. A dual polarity motor with a rotating gear is mounted on the underside of the platform. The motor and rotating gear are placed so as to engage the ring gear in a manner so as to result in rotation of the platform about the axis of the ring gear in a counterclockwise direction when the first switch is impacted or a clockwise direction when the second switch is impacted. A power source for running the motor is provided. 
     When using the training device, the user lies face down on the platform with the right shoulder on the end of the steering bar which impacts the second switch and the left shoulder on the end of the steering bar which impacts the first switch. The user&#39;s legs are separated by the separation means, which may be a battery, a box like structure, a pillow or the like. 
     When falling in a free fall, the diver needs to have the legs separated to allow maximum air flow without adversely changing the position of the diver&#39;s body. By using the device of the present invention, the student diver learns to assume the proper body position for the free fall phase of parachuting. The device requires maintaining the shoulders and torso in the necessary flat position for if a shoulder drops even slightly, the device immediately begins to spin the student simulating what happens during free fall if the proper body position is not maintained. 
     Leg rests may be added to the device by being fastened to the platform, one on each side of the leg separation means. The leg rests further enhance the proper position of the legs when practicing the free fall body position. As the student advances, the leg rests may be removed thus challenging the student to maintain proper position of the legs without the rests. 
     The dual polarity motor with the rotating gear allows relatively simple wiring to be used to have the gear change direction of rotation depending on which switch is activated. The switches preferably are four pole switches, again to allow simplicity when providing the circuitry of the device. 
     The power source for running the motor may simply be conventional electricity, a battery or other suitable power such as a generator or engine. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     FIG. 1 is a perspective view of one embodiment of the present invention; 
     FIG. 2 is a perspective view of the device of the present invention illustrating the position of a student using the device; 
     FIG. 3 is a side elevational view of one embodiment of the present invention; 
     FIG. 4 is a front elevational view showing the steering bar in a neutral position; 
     FIG. 5 is a front elevational view showing the steering bar with the right switch depressed; 
     FIG. 6 is a top plan view of one embodiment of the present invention; 
     FIG. 7 is a top plan view of the ring gear, the swivel, the motor and the rotating gear; and 
     FIG. 8 illustrates the electrical circuitry for the device of the present invention. 
     Corresponding reference characters denote corresponding parts throughout the several views of the drawings. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description illustrates the invention by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the invention, and includes what presently is believed to be the best mode of carrying out the invention. Because changes can be made in the described device without departing from the spirit and scope of the invention, it is intended that all matter contained in this description or shown in the accompanying drawings shall be interpreted as illustrative and not as limiting. 
     FIGS. 1,  2  and  3  illustrate one embodiment of the sky diving training device  10 . To a base  12  is attached a ring gear  30 . A swivel  32  is affixed to the ring gear  30  with the axis of the swivel  32  being directly above the axis of the ring gear  30 . An elongated platform  14  is mounted substantially centered on the swivel  32 . 
     A dual polarity motor  34  is mounted on the underside of the platform  14 . The motor  34  has a rotating gear  36  which engages the ring gear  30  to result in rotation of the platform  14  about the axis of the ring gear  30 . At one end of the platform  14  is attached a shoulder steering bar  16 . The bar  16  is attached to the platform  14  by means of a bracket  24 . The shoulder steering bar  16  pivots from its center and has shoulder pads  18  and  19  so that if the left shoulder of the student  40  pushes downwardly on the shoulder pad  18 , an impact switch  22  is activated and the platform  14  rotates in a counterclockwise direction. If the right shoulder of the student  40  pushes downwardly on the shoulder pad  19 , an impact switch  21  is activated and the platform  14  rotates in a clockwise direction. The impact switches  21  and  22  are mounted on a stationary bar  20 . 
     At the end of the platform  14  opposite the end where the steering bar  16  is mounted, there is a leg separating means  28  mounted on the platform  14 . The leg separating means  28  may be a battery  28  resting on a small platform  38  or other separating means such as a pillow, a box, or other means effecting separation of the legs of the student  40 . In a preferred embodiment, leg rests  26  are mounted onto the platform  14  by means of a bracket  25  on each side of the leg separating means  28 . The leg rests  26  may be removable so as the student  40  progresses, the leg rests  26  are removed thereby requiring the student  40  to hold his legs in the proper position without the benefit of the leg rests  26 . 
     FIGS. 4 and 5 are front elevational views which depict in FIG. 4 the shoulder steering bar  16  at rest with neither the switch  21  nor the switch  22  activated. In FIG. 5, the steering bar  16  has been pressed downward by the right shoulder and thus the switch  21  has been activated causing the platform  14  to rotate in a clockwise direction. When the student  40  realizes that the switch  21  has been activated thus commencing rotation of the platform  14 , the student tends to correct his position by lowering the left shoulder thus activating the switch  22 . When the switch  22  is activated, the platform  14  begins to rotate in a counterclockwise direction. Until the student  40  masters the correct position of the shoulders, the platform  14  will be rotating first in one direction and then in the other direction. The switching bar  20  containing the switches  21  and  22 , can be placed closer to the shoulder steering bar  16  as the student advances to make the shoulder steering bar  16  more sensitive to depression of one of the switches  21  or  22  by one of the shoulder pads  18  or  19 . In summary, the higher the switch bar  20  is moved toward the steering bar  16 , the less depression required to activate one of the switches  21  and  22  thus training the student to become more exact in his body position required for a satisfactory free fall without rotation of the student&#39;s body. 
     FIG. 6 is a top plan view of the device  10 , depicting the platform  14  with the relative positions of the steering bar  16  with the left shoulder pad  18  and the right shoulder pad  19 , and the leg rests  26  attached by the mounting brackets  25 . A battery  28  is depicted mounted so as to be positioned between the legs of the student to remind the student that the legs should be apart to assume the proper free fall position. Other leg separation means can be used when the device is not powered by a battery. For instance, a small box, a pillow or other object can be used as an effective leg separation means. Wires  42  extend from the switching bar  20  under the platform  14  to the power source, in this case, the battery  28 . 
     FIG. 7 presents in detail the manner provided for the platform  14  rotation. A dual polarity motor  34  is activated by the switch bar  20  to rotate a rotating gear  36  either in a clockwise direction or a counterclockwise direction causing the motor  34  (which is attached to the platform  14 ) to rotate about the ring gear  30  resulting in rotation of the swivel  32  about its axis in turn resulting in rotation of the platform  14 . 
     FIG. 8 is a wiring diagram illustrating a power source  28  providing power through a fuse  44  to a switch  46 . The switch  46  is an on-off switch to activate or deactivate the device  10 . When the switch  46  is in the on position, power is provided to each of the switches  21  and  22 . Each switch  21  or  22  is a 4-pole switch requiring depression to complete the circuit and send power to the motor  34 . The motor  34  is a dual polarity motor so as to be responsive to the signal from either of switches  21  or  22 . If the signal is generated by the switch  21  the signal directs the dual polarity motor  34  to rotate the gear  36  in a clockwise direction. If the signal is generated by the switch  22 , the signal directs the dual polarity motor  34  to rotate the gear  36  in a counterclockwise direction. Although the illustration in FIG. 7 depicts a battery  28  as the power source, the power source may be a standard  110  volt AC line, a gasoline generator for generating electricity, a battery or other suitable source. Preferably the power source  28  provides electricity to power the dual polarity motor  34  which motor is sufficiently small to fit on the underside of the platform  14 . 
     The base  12  is any convenient size and shape. For instance, the base  12  can be a platform which is rectangular, oval, elliptical, circular or other desired shape. The base  12  should be of sufficient size to accommodate the ring gear  30 . As an alternative, the base  12  may be a pedestal or a pole so as to mount the device  10  at a desired height from the floor to enable an instructor to easily work with the student. 
     The elongated platform  14  is sufficiently long and wide to easily accommodate the torso of the average student. The leg rests  26  are attached to the platform  14  by use of a mounting bracket  25 . The mounting bracket  25  may extend so as to adjust the distance from the edge of the platform  14  for the leg rests  26  for the comfort of the student. The leg rests  26  may be removed as the student advances thus requiring the student to maintain the proper position without assistance. 
     The leg separating means  28  is a battery, if it is desired that the power source be a battery, or the leg separating means  28  is an object placed so that the student&#39;s legs remain apart when the student is using the device  10 . The object  28  is a battery, a pillow, a foam block, a box or other suitable leg separation means.