Patent Publication Number: US-7585256-B2

Title: Swimming simulation exercise apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   The present application claims the benefit of U.S. Provisional Patent Application No. 60/574,868, filed on May 27, 2004, entitled “SWIMMING SIMULATION APPARATUS”, the entire disclosure of which is incorporated herein by reference. 

   FIELD OF THE INVENTION 
   The present invention is directed to an exercise apparatus and, more specifically, to an apparatus for simulating swimming in the absence of water. 
   BACKGROUND OF THE INVENTION 
   A healthy lifestyle involves good diet and regular exercise. Poor diet and/or little or no regular exercise can have long term adverse health impacts. For example, a person who has a poor diet and who exercises infrequently (or not at all) may be obese, have high blood pressure, high cholesterol, and in many instances a reduced immune system. For these reasons, many doctors and other health industry experts strongly recommend a lifestyle having both a good diet along with a regular exercise routine. Unfortunately, time constraints and/or fiscal restraints reduce the ability for many people to practice such a healthy lifestyle. Furthermore, an injury or other medical condition may reduce a person&#39;s ability to obtain regular exercise. 
   Swimming is recognized to be one of the most beneficial exercise activities. Swimming is known to be a highly aerobic exercise which works many different muscle groups in both the upper and lower body. Swimming also has little or no impact on joints, unlike many other exercise activities. For example, running is known to cause significant joint damage in many individuals who participate in the sport over the long term. Swimming is many times therefore a very beneficial exercise routine for many people, providing many benefits while consuming relatively little time. 
   Swimming provides a cardiovascular workout due to the significant amount of activity involved. In many cases, this cardiovascular workout is equivalent or superior to, for example, running or cycling. In addition to the cardiovascular workout, swimming also provides an efficient and significant upper and/or lower body muscle workout. Many different forms of swimming may be practiced to exercise different muscle groups. For example, a crawl stroke provides a workout to arm muscles including the biceps and triceps, chest muscles including pectoral muscles, abdominal muscles, and back muscles including lats. The breast stroke provides a workout to arm muscles including the biceps and triceps, chest muscles including the pectorals, abdominal muscles, and back muscles including the lats. The back stroke provides a workout to similar muscle groups as well. 
   Many people recognize the positive aspect of swimming, and may desire to integrate swimming into their exercise routine, but choose to use other exercises as their primary aerobic/muscle exercises because of convenience. For example, many people may not have access to a swimming pool, and thus are not able to conveniently participate in a regular swimming exercise routine. Furthermore, certain people may have access to a swimming pool but still not swim because of the requirement to be submersed in water, which may be inconvenient, uncomfortable, and/or impossible. Some people may be restricted from swimming in water for medical reasons, such as, for example, recent surgery. Further, other people may prefer not to swim for more personal reasons, such as a dislike or fear of water, and some people may prefer not to be seen in a bathing suit. 
   SUMMARY OF THE INVENTION 
   The present invention provides a swimming simulation exercise apparatus that simulates the many forces a swimmer is subjected to, thus allowing a user to perform an exercise similar to swimming while not requiring the user to be submersed in water. The apparatus provides a resistance to arm and/or leg motions similar to the resistances a swimmer would experience, and also provides a simulation of the buoyancy that a swimmer would experience. 
   In one embodiment, a simulation exercise apparatus of the present invention comprises (a) a support frame having a first end and a second end; (b) a bench operatively interconnected to the support frame proximate to the first end; (c) an arm cable pulley assembly mounted on the support frame proximate to the second end having a handgrip and a cable interconnected to the handgrip; and (d) a resistance assembly operatively interconnected to the support frame and operatively interconnected to the arm cable pulley assembly. The bench, in an embodiment, has a lower bench portion and an upper bench portion, the upper bench portion distal to the first end. The upper bench portion may comprise an elongate fixed center support and at least first and second wings operably interconnected to the fixed center support on opposite sides thereof. The first and second wings are independently rotatable about said fixed center support. 
   The resistance assembly, in an embodiment, provides resistance against pulling the cable when a force is applied thereto, and provides a restoring force to retract the cable when substantially no force is applied thereto. The amount of resistance provided by the resistance assembly is variable based on the velocity at which the cable is pulled. The amount of resistance provided by the resistance assembly, in one embodiment, is proportional to the square of the velocity at which the cable is pulled. 
   The exercise apparatus may further include a foot cable pulley assembly mounted on the support frame proximate to the first end, comprising a foot support and a second cable interconnected to the foot support; and a second resistance assembly operatively interconnected to the support frame and operatively associated with the foot cable pulley assembly. The second resistance assembly provides resistance against pulling the second cable when a force is applied thereto, and provides a restoring force to retract the second cable when substantially no force is applied thereto. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective illustration of a swimming trainer according to an embodiment of the invention; 
       FIG. 2  is a perspective illustration of a bottom portion of a bench and related swimming trainer for an embodiment of the invention; and 
       FIG. 3  is a side elevation view of a swimming trainer of an embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   The present invention recognizes that numerous physical forces act on a swimmer in water. For example, gravity acts to pull a body and submerse it, and the relative densities of the body with respect to water determine if the body sinks. For example, a solid steel pellet will sink to the bottom of a pool of water, while an inflated plastic ball will float near the surface of the pool of water. The human body, in general, is a neutrally buoyant body and experiences little net external force. The force of gravity is largely offset by the buoyancy of the human body and, in the absence of any current, little net external force is present on the body. It is also recognized that water is a viscous fluid, and an object moving through water experiences viscous drag. Thus, in order to move in water, a swimmer must generate a mean thrust at least somewhat greater than viscous drag in the direction of desired travel. Due to the complex fluid dynamics of water, a swimmer is moving in a turbulent flow profile where inertial pressure forces normal to the surface of the object dominate the system. The inertial pressure forces arise from the average kinetic energy. Kinetic energy is characterized by:
 
½ mv 2   (Equation 1)
 
where m is the mass of the object and v is the velocity.
 
   The force that the swimmer experiences can be related by aerodynamic drag, that is, similar principals as used for designing aircraft. Because of the kinetic energy relationship in a turbulent system, the resistance can be found by evaluating the equation:
 
R=½C b pAv 2   (Equation 2)
 
where R is resistance force, C b  is a drag coefficient, p is the density of the fluid, A is cross-sectional area, and v is the velocity. A swimmer&#39;s body has many moving portions. The torso of a swimmer has a first area and velocity, the swimmer&#39;s hands each have associated second and third areas and velocities, and the swimmer&#39;s feet each have associated fourth and fifth areas and velocities. Taking a single hand, for example, the area and velocity of the hand are the predominant factors in the amount of force experienced at the hand. Because the area of the hand is largely constant, the changes in force felt by a swimmer result primarily from changes in the hand velocity. Accordingly, the present invention recognizes that in order to have a relatively accurate simulation of swimming, it is beneficial to capitalize on the velocity-squared relationship to the resistance force in order to achieve an accurate force profile on a user&#39;s body. In other words, when a user&#39;s hand is moving fastest through the water, the most force is being felt. The resistance mechanism of a swimming training machine of this invention emulates this velocity-squared resistance force to provide a realistic swimming simulation.
 
   With respect to a swimmer&#39;s torso, the presence of lungs, and thus air, in the torso provides additional buoyancy to this portion of a swimmer&#39;s body. When swimming, the torso also feels forces applied by the arms/hands and legs/feet. Many swimming motions result in alternating forces being applied to the sides of the torso. For example, the crawl stroke results in alternating forces being applied on opposite sides of the torso as the swimmer&#39;s arms/legs alternatively stroke/kick. These alternating forces result in the swimmer&#39;s torso rolling about a longitudinal center axis. Further, because the swimmer&#39;s arms and legs may be stroking/kicking at different times, the shoulder portion of the torso may roll about the center axis independently of the hips portion of the torso. Thus, the present invention further recognizes that in order to have a relatively accurate simulation of buoyancy in water, it is beneficial to achieve an accurate force profile on a user&#39;s torso. The bench mechanism of a swimming training machine of some embodiments of this invention emulates the roll of a swimmer&#39;s torso to provide a realistic swimming simulation. 
   Having discussed some of the principles of the act of swimming, some embodiments of the present invention are described with reference to the drawing figures. Referring first to  FIG. 1 , a swimming simulation system  100  of an embodiment of the present invention is illustrated. The system  100  is made of several assemblies, including a dynamic bench  104 , an arm cable pulley system  108  coupled with hand grips  112 , and a foot cable pulley system  116  coupled with a foot hold  120 , and a resistance assembly  124  with attached gearing systems (not shown). All of the assemblies are operatively connected to a support frame  128  which in an embodiment is formed from tubular aluminum, although any material of sufficient size and strength may be used. In this embodiment, users have the option of laying face forward on the dynamic bench  104 , or on their back on the dynamic bench  104 . 
   The dynamic bench  104  in the swimming simulation system  100  is designed to allow a user&#39;s torso to roll about a longitudinal center axis. This allows a user to experience the natural roll similar to that felt while swimming, and also helps prevent the user from injuring their shoulder muscles. Referring now to  FIG. 2 , the assembly of the dynamic bench  104  is now described in additional detail. In this embodiment, the dynamic bench  104  is a three-part bench having a front section  150 , a middle section  154 , and a back section  158 . The back section  158  may be used as leg support or as a seat. The front section  150  of the embodiment of  FIG. 2  has a fixed center portion  162 , and two independent wings  166  coupled to the fixed center portion  162 . In one embodiment, an inside edge of the wings  166  are attached to the fixed center portion  162  by a hinge, although any suitable connection may be used that secures the wings  166  to the fixed center portion  162  and allows the wings  166  to rotate about the point of securement. Similarly, the middle section  154  of the bench  104 , in the embodiment of  FIG. 2 , shares the fixed center portion  162  and has two separate independent wings  170  that are affixed to the fixed center portion  162  in a similar manner as described with respect to wings  166 . 
   The sets of independent wings  166  and  170  are biased in a neutral position by biasing devices  174 . Biasing devices, in the embodiment of  FIG. 2  are pneumatic pistons that are normally in the extended position and move to a retracted position when a force is applied thereto. However, it will be understood that numerous other types of biasing devices may be used, such as, for example, springs, hydraulic pistons, rubberized material, and electrical/magnetic systems, to name a few. The biasing devices  174  are attached to the independent wings  166 ,  170  at a location away from the fixed center portion  162 , and in the embodiment of  FIG. 2 , are affixed at about the midpoint between the inner edge of each wing  166 ,  170  and an outer edge of the wings  166 ,  170 . In this manner, the biasing devices  174  bias each of the wings  166 ,  170  in an upper, or neutral, position and allow the outside edge of a wing  166 ,  170  to move to a lower position when sufficient force is applied to the wing  166 ,  170 . Such a force, for example, may come from a user of the apparatus pulling on a handgrip of the apparatus and performing a swimming type of movement with one arm. The user&#39;s arm, when moving below the plane of the bench  104  exerts an upward force on that side of the user&#39;s body and a resultant downward force on the opposite side of the user&#39;s body. This downward force on the opposite side of the user&#39;s body may apply sufficient force to the respective wing  166  to overcome the biasing force of the biasing device  174  associated with that wing  166 , resulting in the outer edge of the wing  166  moving downward. As each of the wings  166 ,  170  are independently attached to the fixed center portion  162 , and each of the wings  166 ,  170  has an associated biasing device  174 , the bench  104  permits rotation in four independent rotating sections. The wings  170  associated with the middle section  154  of the bench  104  rotate independently of the wings  166  of the front section  150  of the bench  104 . The middle section  154  allows rotation for a user&#39;s hips, and the front section  150  permits rotation for a user&#39;s shoulders. In another embodiment, the front and middle sections of the bench  150 ,  154  may be raised or lowered together by moving an inclination support member (not shown) under the bench up and down an inclined path. In such an embodiment, one or more members of the support frame may telescope, or otherwise be extendable, to provide proper support for all inclinations of the bench, the design of such members being well within the abilities of one skilled in the art. By changing the inclination of the bench  104 , the user may find the position where they are ultimately the most comfortable while using the machine. In the embodiment of  FIG. 2 , there is also an optional third section  158  of the bench located at the back of the system. This section is static and does not rotate or incline, and can be used as extra leg support or as a seat when the other two sections of the bench are inclined. It may also be retracted if a user chooses not to use it. 
   The dynamic bench  104  may also include a head rest (not shown) which provides additional support to a user&#39;s head while using the system. The shape of the bench  104  is generally concave and its surface has a high friction coefficient to enhance safety while reducing the likelihood that a user will slide from the bench  104 . In the embodiment illustrated in  FIGS. 1 and 2 , hip supports  178  are also affixed to the middle section  154  to further help secure the user on the bench  104 . In this embodiment, hip supports  178  are affixed to each of the wings  170 , but may also be mounted on the support frame. If the hip supports  178  are affixed to the wings  170 , the hip supports  178  will also rotate about the fixed center axis  162  when sufficient force is applied to overcome the upward bias of the biasing device  174 . Alternatively, if such hip supports  178  are mounted to the support frame, the wings  170  of the middle section  154  will rotate about the fixed center axis  162  independently of the hip supports  178 . The bench  104  also includes, in an embodiment, a viscoelastic memory foam covering the upper surface of the bench  104 , thus providing additional comfort to a user when using the system. While the dynamic bench  104  illustrated in the drawing figures has two sets of independent wings, it will be understood that such a bench may have more or fewer sets of independent wings. Furthermore, the amount of force required to overcome the force applied by one or more of the biasing devices may be selectable, based on the requirements of the user. 
   The pulley systems of an embodiment of the invention are illustrated in  FIG. 3 . The arm cable pulley system  108  includes a cable  196  which connects hand grip  112  through a first pulley  200  and a second pulley  204  to the resistance assembly  124 . A spooling mechanism  208  is associated with the resistance assembly  124 , and the spools and cable  196 . From the spooling mechanism  208 , the cable  196  is threaded through the second pulley  204 . The cable  196  is then pulled to the top of the frame and threaded through the first pulley  200 . At this point, the cable  196  is attached to hand grip  112 , which the user may then pull when using the system. The top attachment point that attaches the pulleys to the frame may also be adjustable to provide a different height of the top pulleys  200 . In this manner, the height of the top pulleys  200  may be adjusted as appropriate for the particular user and for any inclination of the bench  104 . As a user pulls on the hand grip  112 , tension is created in the cable  196  resulting in the spooling mechanism  208  releasing cable  196  so that the user may start their stroke. Resistance is provided by the resistance assembly  124  as the cable  196  is pulled from the spooling mechanism  208 . 
   A monodirectional clutch is engaged to couple the spooling mechanism  208  to a resistance device  210 . Furthermore, as mentioned above, the resistance assembly  124 , in an embodiment, provides resistance to the cable  196  as is it being pulled, with the magnitude of the resistance depending upon the velocity at which the cable  196  is being pulled. In one embodiment, the resistance is proportional to the square of the velocity at which the cable  196  is pulled. Accordingly, as a user pulls the cable  196  faster, the resistance provided to the cable  196  is increased. When the user is on the recovery phase of the stroke, i.e., they are no longer pulling, a constant force spring within the spooling mechanism  208  retracts the cable  196 . When the user releases the tension from the cable  196 , the monodirectional clutch disengages the resistance device  210  from the spooling mechanism  208 , and the constant force spring provides a retracting force to re-spool the cable  196  onto the spooling mechanism  208 . In one embodiment, the constant force spring retracts the cable  196  with about five pounds of force. However, the amount of force is merely that force which would be required to retract the cable  196 , and may be different than five pounds of force. 
   The spooling mechanism  208  may also have different gearing to couple the resistance device  210  with the spooling mechanism  208 . In this manner, the resistance provided by the resistance device and spooling mechanism may be selected to provide relatively high resistance, relatively low resistance, or a range of resistances, depending upon the gear ratio selected. Such gearing may be accomplished, for example, by having different diameter gears that are available to couple the resistance device  210  to the spooling mechanism  128 . A particular gear may then be selected based on the amount of resistance desired. For example, if a user is a relatively strong swimmer, the user may desire that increased resistance be provided during the swimming strokes. A high gear ratio coupling the resistance device  210  and spooling mechanism  208  may be selected. The amount of force required to pull the cable  196  from the spooling mechanism  208  is thus increased relative to the amount of force required to pull the cable  196  if a lower gear ratio was selected. The resistance provided by the resistance assembly  124  continues to be variable depending upon the velocity at which the cable  196  is pulled as described above. Likewise, if a user desires to have a relatively low resistance provided by the resistance assembly  124 , a low gear ratio may be selected. The spooling mechanism and gearing associated therewith will be described in more detail below. 
   The foot design is such that a foot cable  212  traverses from a rear resistance assembly  124 A through the foot cable pulley system  116  to the foot support  120 . The rear resistance assembly  124 A is substantially similar to the resistance assembly  124  as described above with respect to the arm cable pulley system  108 . The rear resistance assembly  124 A contains a spooling mechanism  208 A, which spools cable  212 . Initially, a user positions the foot support  120  onto the user&#39;s feet by pulling the foot support  120  into position such that their feet may be inserted when the user is lying on the bench  104 . As a user pulls on the foot support  120 , tension is created in the cable  212  resulting in the spooling mechanism  208 A releasing cable  212  so that a user may start their stroke. The spooling mechanism  208 A is coupled to resistance device  210 A as described with respect to the arm resistance assembly  124 . When the user is on the recovery phase of the stroke, i.e., they are no longer pulling; a constant force spring within the spooling mechanism  208 A retracts the cable  212 . In one embodiment, similarly described above, the constant force spring retracts the cable with about five pounds of force. In this embodiment, the resistance assembly  124 A provides resistance to the foot cable  212  and foot support  120  when a user is pulling upward on the foot support  120 . However, in other embodiments additional pulleys may be included in the foot cable pulley system  116  in order to provide resistance when a user is pulling downward on the foot support  120 . In another embodiment, the user&#39;s feet are connected to an elastic device which replaces the rear resistance assembly  124 A and provides resistance in all directions. 
   The spooling mechanisms  208 ,  208 A are largely identical, and will be described with reference to spooling mechanism  208  only with the understanding that other spooling mechanisms for other portions of the system  100  operate in a similar fashion. As mentioned above, the spooling mechanism for the cable is attached to the shaft by a one-way, or monodirectional, clutch. The one-way clutch provides resistance when a torque is applied in a first direction and provides little or no resistance when torque is applied in a second direction. The spooling device is separated by two sections. The first section holds and spools the cable. The second section features a substantially smaller diameter than the first section and attaches the cable or constant force spring that provides a restoring/recoil force. The second section is designed with this smaller diameter in order to minimize the lever arm and overall torque produced by the recoil device. The spooling mechanism  208  includes a gearing system that transfers resistance from the resistance mechanism  124  to the user. The spooling mechanism  208  includes a shaft connected to the resistance mechanism  124 , so that when the cable  196  is pulled, the resistance mechanism  124  is engaged, creating tension in the cable  196  and resistance as felt by a user pulling hand grip  112 . Force transferred to the cable  196  is accomplished by the mono-directional clutch with mild restoring force attached to the cable spool. The restoring force, as mentioned, may be provided by a constant force spring. Force transferred to the user&#39;s arms and legs is accomplished through the cable pulley systems  108 ,  116 . Resistance may be adjusted by the gearing system that varies the gearing ratio, and hence the force output transferred to the user. In an embodiment, the resistance mechanism is an air resistance mechanism, although other types of resistance mechanisms may be utilized. In another embodiment, the resistance mechanism is an air resistance mechanism that provides a resistance that is proportional to the square of the velocity at which the cable is being pulled. 
   While described with reference to a swimming exercise simulation, the apparatus of the present invention may serve a multitude of user directed functions other than swimming simulation. In an inclined position, a user sitting on the bench may perform, for example, an incline press, flies, or a swim stroke in a sitting position. An optional seat that moves on a monorail, or is static, may be included in front of the bench near the pulley system. A user may sit in the seat and perform, for example, lat pull-downs, bench press, rowing exercises, and other exercise that isolate the biceps and triceps. As will be understood, these are just a few examples of the uses of the system. Other applications for fitness and/or rehabilitation are possible as will be readily observable by one of skill in the art. Furthermore, as an alternative to the optional seat in front of the bench near the front pulley system, a wheelchair could be moved into this position. 
   The foregoing discussion of the invention has been presented for purposes of illustration and description. Further, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teaching within the skill and knowledge of the relevant art are within the scope of the present invention. The embodiment described herein above are further intended to explain the best modes presently known of practicing the inventions and to enable others skilled in the art to utilize the invention in such or other embodiments, and with the various modifications required by their particular application or uses of the invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.