Abstract:
A weight machine is used for acceleration movement of heavy weights, and jumping and throwing exercises. The weight machine includes a hydraulic cylinder that will retard movement of the weight under gravity, and will permit free movement against the force of gravity.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a strength and power exercise machine that provides a system in which jumping and throwing exercises can be carried out safely with very low impact forces.  
           [0002]    In the prior art, various types of weight training machines have been advanced, but generally they involve maintaining the weight under the control of the person exercising when both raising and lowering the weights. Jumping and throwing exercises where substantial weight is thrown rapidly involved high impact forces and weight limitations.  
         SUMMARY OF THE INVENTION  
         [0003]    The present invention relates to a weight training apparatus that permits strength and power training with low impact forces. A weight machine that preferably is a squat/overhead press permits the user to grab the press handles or use the shoulder and throw the weight upwardly as rapidly as possible, or do other jumping and throwing exercises. The machine provides a controlled descent rate for the weight through the use of a hydraulic actuator that gives little or no resistance to upward movement of the weights, but controls the rate of descent to a safe level.  
           [0004]    The weights can be mounted onto any type of weight support frame usually on an arm that pivots on a frame, and a hydraulic cylinder or actuator is used between the frame and the weight support arm. A check valve in the hydraulic circuit of the actuator permits free flow between opposite sides of the internal piston in one direction and a controlled bleed back in the other direction.  
           [0005]    Specifically, as shown, the actuator has an internal sleeve with a piston. The piston has a check valve on it, so that when the cylinder is moved in a first direction, there is a free flow of hydraulic oil or fluid from one side of the piston to the other side, but upon movement in the opposite direction, the hydraulic oil that has to be displaced to permit such movement goes through a bleed passageway with a valve that controls the rate of flow so the movement of the piston is restricted to a desired rate. The check valve and bleed valve can be external as well.  
           [0006]    The machine arrangement is reliable, and greatly increases the possibilities for power training by permitting jumping and throwing exercises that are based upon essentially free weight movement in one direction that can be done rapidly, and safely.  
           [0007]    No spotters are required during the exercises, because the weight is maintained under control at all times, and the normal deceleration phase, which requires the athlete to catch and hold the weight during decent, is eliminated because the machine controls the descent of the weight.  
           [0008]    Again, various types of weight machines can be provided with the actuator that controls the descent rate of the weight. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]    [0009]FIG. 1 is a perspective view of a typical overhead press system modified to use the present invention for explosive power training;  
         [0010]    [0010]FIG. 2 is a vertical sectional view of a hydraulic control cylinder used for decelerating the weights and permitting them to return to a starting position;  
         [0011]    [0011]FIG. 3 is an enlarged sectional view of the piston portion of the cylinder shown in FIG. 2; and  
         [0012]    [0012]FIG. 4 is a schematic representation of an equivalent hydraulic control circuit used with the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]    [0013]FIG. 1 illustrates an exercise machine  10  that is essentially a squat/overhead press, which includes a frame  11  having a base  12 , and a platform  14  on which the person exercising will stand. The base  12  supports upright frame members  15  that are spaced apart and are used for supporting a weight system indicated generally at  16 . The weight system includes a first weight support pivoting frame  18  that is pivotally mounted to the frame members  15  on an axis  20  on suitable bearings  22 , in the normal manner. The bearings  22  are at the rear of the upright frame members  15 . The first pivoting frame  18  includes parallel side members  24 ,  24  that support a weight shaft  26  that extends transversely, and on which a number of weights  28  can be mounted. Only one weight is shown on each side of the shaft  26 , but additional weights can be added.  
         [0014]    Any type of weight machine can be used where the weights are on a support that is mounted for movement on a frame, and wherein an actuator can be mounted between the support and the frame.  
         [0015]    A connector bracket  30  is provided in the center of the shaft  26  between the frame members  24 , and a link  32  is pivotally mounted at one end to the bracket  30  on a suitable pin. The link  32  is made so that it can be adjusted in length, in that it has an outer tube  32 A and an inner telescoping tube  32 B that can be adjusted in length using a suitable lock pin  34  that can pass through a selected one of a series of holes on the inner telescoping member.  
         [0016]    The upper end of the link  32  is connected with a pivot connection  36  to a lift bar assembly  38 . The lift bar assembly  38  is also pivotally mounted to upper ends of the frame members  15 , about a horizontal axis  40 . The axis  40  is parallel to axis  20 . One bearing  42  is shown, but a bearing  42  on each frame member  15  is used to mount a suitable pivot mechanism for pivotally mounting the lift frame  38 . The lift frame  38  also has a pair of side frame members  44 , that are spaced apart and include handles  46  for the athlete doing the exercise.  
         [0017]    The first pivot frame  18  includes a cross member  48  between the side frame members  24 . The cross member  48  is positioned between the pivot axis  20  and the shaft  26 . The cross member  48  is also spaced from the link  32 . A hydraulic cylinder  50  has a rod end  51  pivotally mounted to the cross member on a suitable bracket  52 . The hydraulic cylinder  50  has a base end  53  that is pivotally mounted on a pin  54  to a frame cross member  56  that is fixedly supported between the upright frame members  15 .  
         [0018]    The weights  28  are shown in a lowered position, which can be a stopped position, and as shown in FIG. 1, the hydraulic cylinder  50  is extended, with the rod  58  extending out of the cylinder body  60 . Any suitable stop can be utilized for supporting the weights. The user stands on the platform  14 , and grasps the handles  46  in a desired manner and throws the weights  28  upwardly by pushing on the frame  38  as it pivots about the axis  40 . This will cause the weights to be lifted through the link  32  and compress or retract the rod  58  into the cylinder  60 .  
         [0019]    In operation, this throwing of the weights upwardly against the force of gravity is substantially unrestricted by the hydraulic cylinder. The user can actually let go of the weights and the hydraulic cylinder assembly  50  will control the descent of the weights under the force of gravity back to their stopped position for another throw by the athlete.  
         [0020]    In FIG. 2, a longitudinal sectional view of the cylinder assembly  50  is illustrated. The outer cylinder tube  60  and the rod  58  are illustrated in a retracted or compressed position with the rod inside the cylinder. The rod  58  is suitably sealed with a retainer plug  62  on the outer end of the cylinder. The rod  58  carries a piston and check valve assembly  64  on the interior of an inner cylinder tube  66  that is held on the end block  62 , and also is supported on pilot neck  67  on a base end block  68 . That closes the base end of the cylinder tube  60 . The base end block also supports the pin  54 . The piston and check valve assembly  64  includes a piston  69  that mates with check valve plate  70  that is mounted on the rod  58 , and is spring loaded with a conical spring  72  toward the piston  74 . The piston  69  is fixed on the rod  58  and moves with the rod. It can be seen that the check valve plate  70  is slidable on the rod  58 , and will move to the dotted line position shown in FIG. 3 against the force of the spring  72  under differential hydraulic pressure caused as the weights are lifted or thrown up. The check valve plate opens as the extended rod  58  is moved inwardly to uncover passageways  76  and  78  in the piston  74 . The spring  78  surrounds rod  58  and fits in a recess in the check valve plate. The spring is held from sliding on the rod with a snap ring  72 A.  
         [0021]    The end pilot neck  67  of block  68  has a chamber  80 , to permit flow between the passageways  76  and  78 . The interior cylinder  66  is filled with oil and the annular chamber  89  between the inner cylinder  66  and outer tube  60  is also filled with hydraulic oil. When the rod  58  extends to permit the weights to lower, the check valve plate is closed against the piston to prevent oil from flowing through the passageways in the piston. The oil is pressurized and flow out one or more openings  87  in the tube  66  and into the chamber  89 , which cause pressure in the chamber  89 . The block  68  also has a passage  82 , connected to a passageway  84  through a throttle valve assembly  86 , that can be adjusted to control the orifice opening  88  from the passage  82  to the passage  84 . The oil must flow through passageways  84  and  82  across orifice  88 . The rate of flow is controlled by the throttle valve  86 . The speed at which the cylinder rod extends under the force of gravity acting on weights  28  is capable of being controlled.  
         [0022]    A schematic representation of this hydraulic circuit arrangement is shown in FIG. 4, and in this case, the piston rod  58  is shown schematically along with the piston  69 . A check valve is represented at  90 , and will permit free flow through the check valve to the rod end of the cylinder when the piston is moved in the direction of arrow  91 . When the cylinder rod is loaded to extend again in opposite direction, the check valve  90  closes, and the fluid that comes out of the rod end of the cylinder has to go through a passage represented at line  92  and through throttle valve  94 , which is adjustable, and can control a rate of flow of non-compressible fluid (hydraulic oil) so that the rate of descent or movement of the rod  58  can be adjusted and controlled.  
         [0023]    Suitable seals to prevent leakage are provided, as necessary.  
         [0024]    Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.