Abstract:
A multipurpose exercise machine comprising a compact movable frame, a large diameter pulley and a plurality of novel low friction vacuum springs for generating a force is disclosed. The vacuum springs are comprised of two rigid end pieces that are movable relative to each other. A flexible membrane couples the two rigid end pieces to each other and encloses a hermetically sealed region in between the movable bodies and the flexible membrane. A user operating the machine exerts a force that pulls the two end pieces are apart which forms a vacuum that opposes the motion.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    Most exercise machines utilize weights that rely on gravity to create a force that the user of the equipment must overcome. This method of generating a force is reliable however it has many drawbacks, including the high cost of the raw materials of the weights and the high costs of shipping the heavy weights. 
         [0002]    Most exercise machines utilize weights that rely on gravity to create a force that the user of the equipment must overcome. This method of generating a force is reliable however it has many drawbacks, including the high cost of the raw materials of the weights and the high costs of shipping the heavy weights. 
         [0003]    Many exercise machines also use elastic materials to generate a desired force. Unfortunately however, elastic materials degrade over time and the cost of a sufficient amount of the elastic material to generate a large force can be high. 
         [0004]    It is also known in the prior art to create an exercise machine that creates a vacuum to generate a force. Most such exercise machines are comprised of slidable pistons disposed within a cylinder. As the piston moves away from the base of the cylinder a vacuum is created and a force is generated that pulls the piston towards the base of the cylinder. Rubber gaskets typically surround the piston to create an airtight seal between the piston and the cylinder. 
         [0005]    This piston and cylinder arrangement works however it has several drawbacks. For example, to maintain a seal of sufficient quality to keep air from entering the cylinder the seals around the piston have to be very tight and thus they generate a lot of friction. This means that the force of the return stroke will not be as great as the force of the forward stroke. Also any air that does enter the cylinder past the seals must be purged from the cylinder. So such devices often utilize expensive vacuum pumps to maintain the vacuum in the cylinder. 
         [0006]    It has also been disclosed in the prior art to use a bellows like structure to create a vacuum. Unfortunately, however to make a bellows like structure withstand the pressure forces created by high quality vacuum the material that the structure is made from has to be very rigid. And distorting the rigid material would not give the user of the machine a smooth consistent force that would effectively simulate the workout a user could achieve using free weights. Furthermore the inventions disclosed in the prior are that utilize bellows like structures are unable to deliver a constant resistive force to the user. 
       BRIEF SUMMARY OF THE INVENTION 
       [0007]    Accordingly it is an object of this invention to create a multipurpose exercise machine that generates a force by creating a vacuum spring that does not have the drawbacks of a slidable piston disposed within a cylinder or of a bellows like structure. 
         [0008]    Briefly described in a preferred embodiment. The disclosed invention is an exercise machine comprising a compact movable frame, a shaft rotatably mounted on the frame, a large diameter pulley coupled to a shaft, four cams coupled to the shaft, and four novel vacuum springs having one end coupled to the frame and one end that can be coupled to the cams via a flexible linkages such as a strap or cable. 
         [0009]    The vacuum springs are comprised of two rigid end pieces that are movable relative to each other. A flexible membrane couples the two movable bodies to each other and encloses a hermetically sealed region in between the two end pieces and the flexible membrane. The flexible membrane has a concaved shape wherein the bases of the concave are coupled to the end pieces and the apex of the flexible membrane points towards the center of the vacuum spring. 
         [0010]    The two end pieces both have dome shaped surfaces in their center. The apexes of the domes both point in the same direction allowing the domes to interlock with one another and eliminate any open space between the when they are in the closed position. 
         [0011]    When the end pieces move apart no air is able to move into the space between them and a powerful vacuum is created almost instantaneously. The force exerted by the vacuum on the end pieces is almost constant. However as the end pieces move further apart the geometry of the flexible membrane changes and the tensile force exerted by the flexible membrane on the end pieces increases. To compensate for the increasing force and deliver a smooth constant force to the user, the movable end of the vacuum spring is coupled via a strap to a cam that is integrated into shaft. The distance between axis of rotation of the cam and the point where the cam surface and the strap separate decreases as the cam is rotated through the forward stroke. And that distances increases as the cam is rotated through the reverse stroke. 
         [0012]    The four vacuum springs are all made at different sizes so they each generate different resistances. Likewise the sizes of the four cams are also made in different sizes to match the different stroke lengths of the four vacuum springs. One of the vacuum spring and cam combinations provides 15 lbs of resistance to the user, another provides 20 lbs, another provides 25 lbs, and the largest spring provides 30 lbs. One or more of the vacuum springs can be coupled to the cams at any one time. This enables to the user to adjust the resistance of the machine in 5 lb increments from 15 lbs all the way up to 90 lbs. Other size combinations are also possible. 
         [0013]    The base of the frame is mounted on a hinge that allows the machine to tilt about a horizontal axis. The base of the frame of the machine is then mounted to a foundation that the user can stand on or a bench or seat can be placed on. Two of the disclosed machines are utilized in the preferred embodiment so that the user can exercise two arms or legs at one time. Also the foundation has multiple mounting locations so that the two instances of the machine can be positioned in different locations allowing for different types of exercises and to accommodate people of different sizes. 
         [0014]    These and other features and advantages of the present invention will become more apparent to one skilled in the art from the following description and claims when read in light of the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         [0015]    The technology described herein will be better understood by reading the detailed description of the invention with reference to the accompanying drawing figures, in which like reference numerals denote similar structure and refer to like elements throughout, and in which: 
           [0016]      FIGS. 1A and 1B  are front views of the vacuum spring used by the present invention; 
           [0017]      FIG. 2  is a side view of the vacuum spring of the present invention; 
           [0018]      FIG. 3  is a cross-sectional view of the components of the vacuum spring of the present invention; 
           [0019]      FIG. 4A  is a left side view of a preferred embodiment of the present invention; 
           [0020]      FIG. 4B  is a front view of a preferred embodiment of the present invention; 
           [0021]      FIG. 4C  is a right side view of a preferred embodiment of the present invention; 
           [0022]      FIG. 5  is a left side view of a preferred embodiment of the present invention with the left side plate removed to show the internal components; 
           [0023]      FIG. 6  is a front view of a preferred embodiment of the present invention with the front plates of the frame removed to show the internal components; 
           [0024]      FIGS. 7A and 7B  are cross sectional views of a cam utilized by the present invention; 
           [0025]      FIG. 8  is a front view of a complete exercise system utilizing two instances of the present invention; 
           [0026]      FIG. 9  is a top view of a complete exercise system utilizing two instances of the present invention; 
           [0027]      FIG. 10  is a cross-sectional view of the two end pieces positioned next to each other. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    In describing the preferred and alternate embodiments of the present invention, as illustrated in  FIGS. 1-10 , specific terminology is employed for the sake of clarity. The invention, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish similar functions. 
         [0029]    Referring now to  FIG. 1A , illustrated therein is a front view of a vacuum spring  20  used by the present invention in the closed position. A rigid moveable end piece  21  is at the top of the vacuum spring. A fixed rigid end piece  26  is at the bottom. A flexible membrane  25  couples the two end pieces together. Two clamps  24  couple the top and the bottom of the flexible membrane to the end pieces whereby an airtight seal is created between the end pieces and the flexible membrane  25 . An attachment structure  22  protrudes from the movable en piece  21 . The attachment structure  22  is used for connecting the movable end piece to a flexible linkage that is attached to a cam. In this embodiment the attachment structure  22  has three holes in it that will allow three hooks that are attached to a strap to hook onto the attachment structure. The moveable end piece  21  also has two guide surfaces  23  (only one is visible here) that protrude from it. The guide surfaces  23  ensure that the end piece  21  moves only in the desired direction, which in the case is directly upward from the fixed end piece  26 . This is necessary because 
         [0030]    Referring now to  FIG. 1B , illustrated therein is a front view of the same vacuum spring  20  in  FIG. 1A . However in  FIG. 1B  the vacuum is in the open position as the two end pieces  21  and  26  have been pulled apart and a vacuum has been created in the region between the end pieces and the flexible membrane  25 . Thus the atmosphere is now exerting a force on the two end pieces  21  and  26  and the flexible membrane  25  that pushes the two end pieces toward each other. 
         [0031]    Referring now to  FIG. 2 , illustrated therein is a side view of the vacuum spring  20 . 
         [0032]    Referring now to  FIG. 3 , illustrated therein is a cross-sectional view of the components of the vacuum spring  20  of the present invention. Here the dome shaped structures that make up the two interlocking end pieces  21  and  26  are clearly visible. The interlocking surfaces of the end pieces  21  and  26  could simply be flat surfaces, however this design would be very inefficient as much more material would be required to enable a flat surface to withstand the pressure forces exerted by the atmosphere than a dome shaped surface would. The dome also transfers the forces exerted on the movable end piece to the center where the attachment structure is. 
         [0033]    Also clearly illustrated in  FIG. 3  are the two base ends  27  of the flexible membrane  25  and the apex  28  of the membrane  25  that loops around the membrane and points toward the center of the vacuum spring  20 . Also shown are two high tensile strength filaments  29  that are embedded into the flexible membrane. A large number of these filaments can be embedded into the membrane. They are oriented parallel to each other and traverse the membrane  25  from one base end  27  to the other through the apex  28  of the membrane  25 . They transfer pressure forces exerted by the atmosphere on the flexible membrane  25  to the end pieces  21  and  26 . 
         [0034]    Also shown in  FIG. 3  is a hole  31  in the middle of the end piece  26  and a one-way valve  32 . The hole and the valve can be used to purge any air they may leak into the vacuum chamber out of the chamber. This feature is not necessary for the spring to operate however it would be useful if any air ever leaks into the vacuum spring  20 . 
         [0035]    Referring now to  FIG. 4A , illustrated therein is a side view of a preferred embodiment of the present invention  1 . A handle  2  is attached to a cable  3 . A top handle  4  attaches to the top of the invention  1  so that it can be easily moved. A left side wall  5  covers the side of the invention  1  and comprises part of the frame of the invention. Two knobs  6  (only one is visible here) protrude from the front of the invention. There are there so that the cable  3  can be wrapped around them when the machine is not in use. Four force selection knobs  15  protrude from the side wall  5 . They are used to engage or disengage the four vacuum springs used by the invention. They operate by being pulled slightly outward and then slid from one side to the other. 
         [0036]    A base  7  is positioned beneath the frame. A hinge  8  couples the bottom of the frame to the base  7 . The hinge  8  allows the frame to tilt about a horizontal axis so that the user of the invention can pull the cable  3  in multiple directions. Two springs  10  (only one is visible here) are positioned on both sides of the hinge  8  and keep the exercise machine completely upright when no force is exerted on it. 
         [0037]    Referring now to  FIG. 4B , illustrated therein is a front view of the present invention. Here the front of the large diameter pulley  9  is visible. The cable  3  is wrapped around the pulley  9 . The large diameter pulley  9  is sufficient in size to allow the uses to complete a stroke of an exercise without rotating the pulley more than 360 degrees. The enables the cams utilized by the invention to work properly. 
         [0038]    When a user pulls on the handle  2  the pulley rotates and provides a resistance to the user that opposes his motion. However on the return stroke the pulley pulls the cable away from the user and effectively simulates a workout that can be achieved with free weights. The arrow  11  shows the additional range of motion provided by the hinge  8 . 
         [0039]    Referring now to  FIG. 4C , illustrated therein is a right side view of the present invention. Here the side of the large diameter pulley  9  is visible. The arrow  12  shows the additional range of motion provided by the large diameter pulley  9 . The combined degrees of freedom of motion provided by the hinge and the pulley make the invention  1  very flexible and useful for a large number of exercises. 
         [0040]    Referring now to  FIG. 5 , illustrated therein is a left side view of a preferred embodiment of the present invention with the left side plate removed to show the internal components. A rotatable shaft  16  is mounted on bearing in the center of the frame. Four rtraps or flexible linkages  31  are attached to cams that are machine into the shaft. The other ends of the four straps are connected to hook structures  32 . The hook structures have three prongs that protrude from them and can engage the holes on the vacuum spring attachment structures  22 . Eight guide posts  30  protrude from the side of the frame and are positioned next to the guide surfaces  23 . These guide posts ensure that the movable ends of the vacuum springs move only in the desired direction. 
         [0041]    Referring now to  FIG. 6 , illustrated therein is a front side view of a preferred embodiment of the present invention with the front plates of the frame removed to show the internal components. However only two of the four vacuum springs  20  are shown for the sake of clarity. Two elastic ropes  17  traverse the frame from the right wall to the hook structures  32  and then to the force selection knobs  15 . When the force selection knobs  15  are slide back and forth, the hook structures  32  slide back and forth and the prongs of the hook structures engage and disengage the attachment structures of the vacuum springs  20 . 
         [0042]    Referring now to  FIGS. 7A and 7B , illustrated therein are cross sectional views of a cam  34  utilized by the present invention. The cam  34  is machined into the shaft  16 . A flexible linkage  31  is attached to the cam via a mechanical fastener  35 . The arrow in  FIG. 8A  shows the direction that the cam will rotate during the forward stroke. The arrow in  FIG. 8B  shows the direction that the cam will rotate during the reverse stroke. 
         [0043]    Referring now to  FIG. 8 , illustrated therein is a front view of a complete exercise system utilizing two instances of the present invention. Two of the exercise machines  1  are attached to a foundation  43 . The only difference between the two machines  1  is that the pulleys are mounted on different sides. The foundation has multiple points where the exercise machines  1  can be positioned so that the user can perform a huge range of different exercises. The exercise machines  1  can also be rotated in different directions about a vertical axis so that even more exercises can be performed. 
         [0044]    A bench  40  can be positioned on top of the foundation  43  so that exercises like bench presses can be performed. The bench also has two attachment structures  41  that the bases of the exercise machines  1  can be mounted on. Footrests  42  also protrude from two of the benches legs for use in exercises like seated lat rows. 
         [0045]    Referring now to  FIG. 9 , illustrated therein is a top view of a complete exercise system utilizing two instances of the present invention previously illustrated in  FIG. 8 . Also visible here is a plurality of mounting holes  44  where the exercise machines  1  can be positioned on. The attachment structures  41  that are mounted on the bench  40  also have mounting holes. 
         [0046]    An optional leg curl attachment could be added to the bench. And one or both of the exercise machines  1  could be drivenly connected to the leg curl attachment. One or more of the mounting holes in at the top middle of the foundation could be uses for the purpose. 
         [0047]    Referring now to  FIG. 10 , illustrated therein another cross-sectional view of the two end pieces wherein they are positioned right next to each other to show how are gaps between them are eliminated. 
         [0048]    Of course a huge number of alternative embodiments of the present invention could also be created. In one alternative embodiment adhesives could be used rather than a mechanical fastener to couple the membrane to the end pieces. Also an enormous number of different configurations could be used to engage the vacuum springs could be employed. For example the user could connect the hooks to the movable ends of the vacuum springs manually. In another embodiment the components of the frame and the stationary end pieces of the vacuum springs could be integrated into one solid piece. Furthermore all of the vacuum springs could be permanently attached to the cams and valves could be used to control air into and out of the vacuum springs. The valves could be opened to essentially eliminate the resistance created by the vacuum springs. Also the fixed end pieces of the vacuum springs could be welded, bolted, clamped, etc. to the frame. Also the shaft, cams and pulley could all be created from one solid piece of material. Additionally, the multiple filament segments used in the flexible membrane could be made from one long filament that is looped back and forth from one base of the membrane to the other wherein the segments of the filament are still oriented parallel to each other. A guard to cover the pulley could extend outward from the frame. 
         [0049]    Having thus described exemplary embodiments of the technology described herein, it should be noted by those skilled in the art that the within disclosures are exemplary only, and that various other alternatives, adaptations, and modifications may be made within the scope of the technology described herein. Accordingly, the technology described herein is not limited to the specific embodiments illustrated herein, but is limited only by the following claims.