Abstract:
An exercise machine in which a fan has a rotor that generates drag by causing air to move in response to exercising by a user. A deflection structure deflects air that the rotor has moved and is adjustable to control the amount of drag generated by the rotor.

Description:
This is a continuation of application Ser. No. 09/329,915, filed Jun. 10, 1999, now U.S. Pat. No. 6,561,955. 

   BACKGROUND  
   This invention relates to machine-assisted exercising. 
   Exercising is frequently done with the help of an exercise machine that resists motion of the exerciser&#39;s arms or legs. 
   Some machines, such as rowing machines and cycling machines, resistive forces that are small enough to permit aerobic exercising over a longer period of, say, 20 to 40 minutes. 
   Other machines, such as weight machines, offer higher resistive forces for so-called resistance exercising that entails fewer repetitions. 
   Some exercise machines use wind drag created by a fan to provide the resistance. 
   SUMMARY  
   In general, in one aspect, the invention features an exercise machine in which a fan has a rotor that generates drag by causing air to move in response to exercising by a user. A deflection structure deflects air that the rotor has moved and is adjustable to control the amount of drag generated by the rotor. 
   Implementations of the invention may include one or more of the following features. The rotor moves and the deflection structure remains stationary. The deflection structure has deflection surfaces, e.g., curved vanes, at least one of which is adjustable relative to the path of air that the rotor has moved. Each of the deflection surfaces is independently rotatable from an open position to a closed position. 
   The deflection structure and the rotor are located at different positions along an axis of the rotor. An air directing surface is positioned to deflect air from the deflection structure toward the fan rotor. A closed housing surrounds the rotor and the deflection structure. 
   In general, in another aspect of the invention an outer dimension of the fan rotor and in inner dimension of the housing define a cylindrical chamber, and the fan rotor vanes direct air from inside the rotor to the cylindrical chamber and cause swirling of the air in the chamber. 
   In general, in another aspect, the invention features an exercise machine that has a fan that generates drag by causing air motion, a beam, a carriage, and a seat. The carriage rides back and forth along the beam and is coupled to drive the fan in response to force applied by a user exercising. The fan is driven when the carriage is riding in one direction along the beam and is undriven when the carriage is riding in the other direction along the beam. A seat is configured to be movable to different positions along the beam relative to the carriage and to different orientations relative to the carriage. 
   Among the advantages of the invention may be one or more of the following. The wind resistance provided by the fan may be adjusted to provide different exercise experiences. Different exercise modes may be achieved by rearranging the seat relative to the moving carriage, adjusting the seat angle, and adjusting the handle height. In the case of strength training, wind resistance eliminates the need for hundreds of pounds of weight. The force experienced by the user is determined by the user effort. This means the muscles can be appropriately stressed through the entire range of motion. With commonly used weight-lifting equipment, the muscles may be stressed at the proper level only at the place in the exercise motion where the muscles are the weakest. 
   Other advantages and features will become apparent from the following description and from the claims. 

   
     DESCRIPTION OF THE DRAWINGS  
       FIGS. 1 and 2  are top and side views, respectively, of an exercise machine. 
       FIG. 3  is a perspective view of an opened fan canister. 
       FIGS. 4 and 5  are a wire frame perspective view and an end view, respectively, of a fan rotor. 
       FIG. 6  is a partial end view of stator vanes. 
       FIG. 7  is a perspective view of a fan canister viewed from the lid end. 
       FIGS. 8 and 9  are schematic views of airflow inside the fan canister. 
   

   DESCRIPTION  
   As seen in  FIGS. 1 and 2 , in an exercise machine  10 , a wind-generating fan  12  imposes a selectable amount of resistive force as a carriage  14  is pushed or pulled along a beam  16  by a user (not shown). 
   The wind-generating fan  12  is driven by motion of the carriage through a system of chain loops and pulleys. One chain loop  20  connects a pulley  22 , which is mounted between the fan&#39;s axle  24 , to a larger pulley  26 , which is mounted on a pair of brackets  27  (only one shown) at one end of the beam  16 . A second chain loop  30  connects a smaller pulley  32 , which is mounted on the same axle as pulley  26 , to a free wheeling pulley  40  mounted at the other end of the beam. A bracket  42 , which is attached to the carriage  14 , also grips the second chain loop  30 . 
   As the carriage is forced back and forth along the beam, the second chain loop drives pulley  26 , and pulley  32  in turn drives pulley  22 . A one-way clutch on the axle of the fan (not shown in  FIGS. 1 and 2  but seen in  FIG. 3 ) permits pulley  22  to drive the fan in direction  21  when the carriage is moving in a driving direction  23  along the beam. When driven, the fan spins, generating air resistance in a manner described below. The air resistance is converted to a force that resists linear motion of the carriage and enables a user to exercise by pushing or pulling on the carriage. 
   The one-way clutch allows the fan to freewheel when the carriage is moving in a coasting direction  25  along the beam. The user may return the carriage to its original position in the coasting direction with little effort and then may repeat the cycle for repetitive exercise. 
   The relationship between the linear velocity of the carriage and the rotational velocity of the fan, and the corresponding relationship between the air resistance generated by the fan and the linear resistance on the carriage, are determined by the sizes of the pulleys. The sizes are chosen to provide an appropriate exercise experience. 
   The carriage is configured to enable the user to apply force by pushing or pulling through his arms and hands or by pushing his legs and feet, or by doing both. In other possible configurations, the user&#39;s legs and feet could be pulled to move the carriage. 
   A handle bar  60  is mounted on the carriage to permit pushing or pulling by hand. A pair of rigid straps  62  with hand stirrups  64  are attached to the handle bar to permit pulling by hand. The handle bar may be adjustably mounted so that the height may be set to suit the user and the type of exercise. Footrests  70 ,  71  on either side of the carriage permit pushing with the feet. 
   A seat  72  (the seat is shown twice in  FIG. 1 , in two different positions, one position  72   a  for pulling, the other position  72   b  for pushing), includes a vertical seat back  80  and a horizontal seat bottom  82 . 
   In the pulling position  72   a,  the seat bottom is on the other side of the seat back from the carriage. In that position, the user sits on the seat bottom facing the carriage and his chest is supported against the vertical face of the seat back as he pulls. 
   In the pushing position  72   b,  the seat bottom is on the same side of the seat back from the carriage. In that position, the user sits on the seat bottom facing the carriage and his back is supported by the seat back as he pushes. 
   Other seat positions would also be possible such as one in which the user sits at the pull end and faces away from the carriage. 
   The seat back is mounted to the seat bottom through a bracket  89  that supports the seat back on one pivoting support  90  and a second adjustable support  92  that cooperates with a series of holes  94  on the seat back to permit the angle of the back to be adjusted. 
   The seat bottom  82  and the bracket  89  are part of a seat base  91  that also includes a square steel post  96 , which is held within one or the other of two square steel legs  100 ,  102  located at opposite ends of the beam. The post  96  has a vertical column of holes  97  that cooperate with one or more holes in the sides of the beam legs to permit the height of the seat to be adjusted using pins. 
   The leg  100  on the pull end of the exercise machine has a foot  101  at its bottom end that rests on the floor. The leg  102  on the push end of the exercise machine has a foot  103  at its bottom end that also rests on the floor. The pull end leg  100  has a bracket  131  that is connected to and supports the bottom of the beam at the pull end. The push end leg  102  supports the push end of the beam indirectly on brackets  27 . 
   As seen in  FIG. 3 , the fan  12  includes a closed canister  123  (shown open in  FIG. 3 ) comprising a cylindrical housing  122  and a lid  124 . As also seen in  FIGS. 4 and 5 , the fan includes a rotor  127  having a cylindrical cage  129  with a number (e.g.,  32 ) of curved fan blades  131  arranged with equal spacing around the axis of the cage. The rotor has a flange  133  to permit the rotor to be mounted on a rotating disk. The rotating disk is attached to a hub which contains the clutch and bearings. The outer diameter of the rotor could be, for example, 14 inches, and the inner diameter of the cage housing  122  could be, for example, 18 inches, leaving a cylindrical open chamber ( 184  in  FIG. 8 ) about 2 inches thick for circulation of air. When the rotor is being driven by motion of the carriage, it rotates in direction  141  shown in  FIG. 5 . 
   Referring again to  FIG. 3 , the lid supports a set of (e.g., eight) adjustable vanes  126  arranged in a circle at equal spacing around the axis of the lid to form a stator that interacts with the rotor through air flow within the canister to generate air drag. The stator also includes a bowl-shaped air deflector  130  mounted on the lid inside the ring of vanes. 
   As seen in  FIG. 6 , each vane  126  has an air deflection surface  140  in the shape of a section of a cylinder and a base  142 , which supports the air deflection surface. The base has a hole  144  that permits mounting the vane on the lid by a fitting  145  ( FIG. 7 ) that allows the vane to be rotated  146  around the fitting. 
   As seen in  FIG. 7 , on the outside of the lid, each vane has a positioning lever  158  that allows a user to turn the vane to a desired angular position to control the amount of air resistance generated by the fan. 
   The vane fitting  145  resists rotation so that the user can adjust the vane by hand, and the vane will not shift from its adjusted position until adjusted again. 
   Referring again to  FIG. 6 , each vane can be adjusted from a fully closed position  148  to a fully open position  150 . In the fully closed position, the tip  151  of the vane almost touches the other end  152  of the next vane  153  of the ring. In the fully open position, the tip of the vane touches the inner wall of the canister housing when the canister is closed. 
   As shown in  FIGS. 8 and 9 , the housing  122  is deeper  180  than the height of the rotor. The remaining space accommodates the stator when the canister is closed. The stator is about the same height as the rotor. 
   The vanes of the stator can be adjusted between two extreme configurations. At one extreme, shown in  FIG. 8 , all stator vanes are turned to the closed positions. This effectively divides the outer end of the canister into two chambers, a round central chamber  60  surrounded by a cylindrical outer chamber  62 , with only a small amount of leakage ( 182  in  FIG. 6 ) allowing air to flow between them. The outer chamber  62  is essentially an extension of the chamber that surrounds the rotor. 
   In the other extreme configuration, all vanes are open. The tips of all of the vanes touch the inner wall of the canister, effectively eliminating the outer cylindrical chamber  62 . 
   Although the exact details of the airflow within the canister are not known, it is believed that the following considerations apply. 
   Because of the one-direction clutch on the axle of the rotor, the rotor can only rotate in the direction  141  in  FIG. 5 , in which the curved vanes act as scoops to pick up air from the space within the rotor and direct it (arrows  191 ) to the cylindrical chamber outside of the rotor. This motion tends to set up a whirl of air  193  that rotates around the outer chambers of the canister in the same direction in which the rotor is rotating. 
   As seen in  FIG. 8 , when the stator vanes are in the fully closed configuration, the cylindrical chamber that surrounds the stator is in line with the donut shaped chamber that surrounds the rotor. Only a small proportion of the air leaks back  195  into the chamber within the rotor, where it is again thrown out into the donut-shaped chambers. Because there is relatively less re-circulation of the air within the canister the amount of drag resistance imparted to the user is also relatively less. 
   Conversely, when the stator vanes are in the fully open configuration, the air flow from the rotor is constantly striking the deflection surfaces of the stator vanes (shown, as to one stator  300 , in  FIG. 9 ) and is being redirected  302  into the central part of the canister where it can be re-circulated by the fan. The redirection of the air is aided by the surface  134  of the air deflector  130 . As seen in  FIG. 6 , the vanes of the stator are oriented to have the opposite curvature of the vanes  131  of the moving rotor  127 . 
   Because there is relatively more re-circulation of the air than in the fully closed case, the amount of drag resistance is also relatively greater. 
   By adjusting one or more of the vanes, a range of configurations between the two extremes can be set, such as the one shown in  FIG. 9 . Because each vane can be adjusted to any position between open and closed, virtually any desired resistance level between those achieved by the two extreme configurations can be obtained. 
   In any of the stator configurations, the faster the fan is rotated, the more drag is created. A so-called drag factor accounts for changing conditions of the fan including airflow to the fan and air density. As explained, the configuration of the stator vanes alters the airflow to the fan. When all stator vanes are closed the drag for a given rotational speed will be lowest. Opening each stator vane will increase the drag by a factor of about 45%. With all stator vanes open, the drag factor is about 20 times greater than when all are closed. The large range of drag factor makes the exercise machine useful for a variety of strength training exercises. 
   Referring again to  FIG. 1 , a magnetic sensor  180  is attached to the fan canister to measure the speed of the fan. A cable  182  carries the information to a display  184 , which is mounted in a position where the user can see it easily. The monitor displays exercise performance values such as force, time, speed, work, power and repetition information. These values are based on the principles described in U.S. Pat. No. 4,875,674, incorporated by reference. Other embodiments are within the scope of the following claims. For example, other configurations of exercise positions, beams, and carriages can be used.