Abstract:
A rowing trainer includes a frame, and a seat affixed to the frame. A sliding rigger, which supports an oar assembly, is movable back and forth along the frame. The oars are indirectly connected to a cord which passes around at least one pulley, and which turns a flywheel. Neither the flywheel nor the seat translates relative to the frame. The only component which translates is the rigger and the associated oar assembly. The device closely simulates the experience of rowing an actual boat or scull.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to the field of athletics training, and provides a rowing machine which closely simulates the feel of a scull or boat. 
     Rowing machines have been known for many years. Examples of such machines are shown in U.S. Pat. Nos. 228,845, 381,187, 641,596, 1,504,375, 2,586,024, 3,572,700, 4,047,715, 4,396,188, 4,743,011, 4,846,460, 4,880,224, 4,884,800, 4,984,986, 5,013,033, 5,092,581, 5,295,931, 5,441,469, and 5,779,600. The disclosures of the above-cited patents are incorporated by reference herein. 
     Rowing machines are used by the majority of rowing clubs and teams to improve fitness during inclement weather, as well as to supplement rowing training when there are a large number of athletes and insufficient coaches. 
     A typical rowing machine of the prior art has a sliding seat which moves along the longitudinal axis of a simulated boat. In an actual racing scull or boat, the seat is movable along a pair of tracks, so that the seat slides during each rowing stroke. 
     As the scull or boat moves through the water, its center of gravity translates with the athlete. The boat may weigh as little as thirty pounds, and may thus constitute only about 10-15% of the total mass of the system which includes the boat and the athlete. In relation to the motion of the center of mass of the entire system, it is more accurate to describe the boat as translating with respect to the athlete, than to characterize the athlete as moving on the slide. 
     Although rowing machines of the prior art have generally used a sliding seat to accommodate the rowing motion, they do not accurately reproduce the “feel” of the boat. Rowing machines typically incline the tracks, within which the seat translates, to simulate the actual feel of the boat, as the athlete progresses through a stroke. 
     Some of the rowing machines of the prior art do not simulate the motion of the oars about an oar lock, and therefore do not exercise the same muscles that would be used in actual rowing. In such cases, the athlete must deal with an abrupt transition between what is experienced during training and what is felt during actual rowing. 
     The present invention provides a rowing trainer which more closely simulates the actual experience of rowing a scull or boat. The device of the present invention also accurately simulates the movement of the oars. It also enables the athlete to monitor the progress of the rowing activity. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a rowing trainer having a frame and a seat which is affixed to the frame. The seat does not move relative to the frame when the rowing trainer is in use. The device further includes a rigger which supports an oar assembly, the rigger being slidable relative to the frame. The device also includes at least one flywheel, mounted to the frame, such that the flywheel does not translate relative to the frame. 
     The oar assembly includes at least one oar which is connected, by a link, to an underframe arm, the link being held within a hollow tube that is rigidly connected to a frame of the rigger. Pulling on the oar rotates the link, and therefore causes the underframe arm to rotate, in a manner similar to that of the oar. 
     The underframe arm has a free end to which there is attached a cord. The cord passes around a castering pulley, which is attached to the rigger, and then around a pulley or sprocket positioned at or near the flywheel. The cord then extends substantially the length of the frame, and is attached to the frame, preferably through a spring or other elastic component. When the athlete pulls the oar, the energy of the oar is transmitted to the underframe arm, through the cord, and to the flywheel. 
     The rigger preferably includes a foot rest, which translates with the rigger, relative to the frame. Thus, not only does the athlete push and pull on the oars, but the athlete also pushes on the foot rest, which will move back and forth with the rigger. 
     The rowing trainer of the present invention may also include a monitor or display screen, mounted to the frame, and positioned to be visible by the athlete using the machine. The monitor may display a comparison of the rotational velocities of two flywheels, to show the athlete the trajectory of the simulated boat. 
     The rowing trainer thus described minimizes the amount of energy consumed during the rowing operation, insofar as the majority of the mass of the athlete&#39;s body does not move during the rowing stroke, due to the fact that the seat is stationary. The only component which exhibits translational motion relative to the frame is the rigger and oar assembly. The motion of the flywheel is rotational only; the flywheel does not translate relative to the frame. 
     The invention also includes the method of operating the rowing trainer described above. 
     The present invention therefore has the primary object of providing a rowing trainer. 
     The invention has the further object of providing a rowing trainer which closely simulates the experience of rowing a boat or scull. 
     The invention has the further object of providing a rowing trainer which minimizes the energy expended in moving the athlete&#39;s body. 
     The invention has the further object of providing a rowing trainer with a non-translating flywheel, so that work can be performed in turning the flywheel by operation of the oars. 
     The invention has the further object of providing a rowing trainer which can be made with either one or two oars. 
     The invention has the further object of providing a rowing trainer which displays, to the user, information concerning the rowing operation. 
     The invention has the further object of providing a method of operating a rowing trainer. 
     The reader skilled in the art will recognize other objects and advantages of the present invention, from a reading of the following brief description of the drawings, the detailed description of the invention, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1   a ,  1   b , and  1   c  provide perspective views illustrating the three basic components of a rowing stroke, in the prior art. 
         FIG. 2  provides a perspective view of the rowing trainer of the present invention. 
         FIG. 3  provides a perspective view of the rowing trainer of the present invention, the view being taken from a direction which is generally opposite to that of  FIG. 2 . 
         FIG. 4  provides another perspective view of the rowing trainer of the present invention. 
         FIG. 5  provides a perspective view of the rowing trainer of the present invention, and also showing an athlete seated on the device. 
         FIG. 6  provides a top view of the rowing trainer of the present invention. 
         FIG. 7  provides a cross-sectional view of the rowing trainer of the present invention, taken along the line VII-VII of  FIG. 5 . 
         FIG. 8  provides a bottom view of the rowing trainer of the present invention. 
         FIG. 9  provides a perspective view of portions of the rowing trainer of the present invention, showing the connections of the cords and flywheels. 
         FIG. 10  provides a perspective view of the frame of the rigger used in the present invention. 
         FIG. 11  provides a perspective view of the entire rigger and oar system of the present invention. 
         FIG. 12  provides a fragmentary perspective view, showing an oar connected by a link to its associated underframe arm, as used in the present invention. 
         FIGS. 13   a  and  13   b  provide, respectively, a perspective view and a top view, of the rowing trainer of the present invention, in the “catch” position of the stroke. 
         FIGS. 14   a  and  14   b  provide, respectively, a perspective view and a top view, of the rowing trainer of the present invention, in the “drive” position of the stroke. 
         FIGS. 15   a  and  15   b  provide, respectively, a perspective view and a top view, of the rowing trainer of the present invention, in the “finish” position of the stroke. 
         FIG. 16  provides a perspective view of an alternative embodiment of the present invention, in which there is only one oar. 
         FIG. 17  provides a block diagram showing the connection of the flywheels to a computer, so as to enable real-time monitoring of the rowing action, in the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention comprises a rowing trainer which simulates the actual experience of rowing a scull or boat. 
       FIGS. 1   a - 1   c  illustrate the three major stages of a rowing stroke. These stages are labeled “catch”, “drive”, and “finish”, and apply both to the prior art and to the present invention. Reference will be made, later, to these stages, in describing the device of the present invention. 
       FIG. 1   a  shows a rower in a scull or boat, in the “catch” position. In this position, the athlete&#39;s legs are compressed, and the arms are extended. The oars are about to engage the water to perform the work of rowing. 
       FIG. 1   b  shows the rower in the “drive” position. The athlete&#39;s legs are nearly extended, and the arms are beginning to bend. This is the portion of the stroke which accomplishes most or all of the work of rowing, as the oars are moved through the water, with the oar blades oriented for maximum engagement with the water. 
       FIG. 1   c  shows the rower in the “finish” position. The athlete&#39;s legs are extended, the arms are bent, and the oar grips are at the athlete&#39;s side. The work of the rowing stroke has been completed. 
       FIGS. 2 ,  3 , and  4  provide perspective views of the rowing trainer of the present invention, taken from different directions. The rowing trainer includes frame  1  and seat  3 , the seat being affixed to the frame. The seat does not move relative to the frame during the rowing operation. Also, the frame is stationary with respect to the ground. A rigger  7 , which slides back and forth along the length of the frame, supports an assembly for holding oars  8  and  9 , and also supports foot rest  5 , which comprises a generally flat plate inclined from the horizontal. The rigger also provides partial support for a system of cords, to be described later. 
     Although the seat does not move relative to the frame while the rowing trainer is in use, the seat may be made adjustable, so that its position along the frame may be changed, to suit the preferences of an individual user. However, the movement of the seat occurs only while the device is not in use. When actual rowing is in progress, the seat remains fixed relative to the frame. 
     The foot rest may be provided with one or more straps or shoes (not shown) to secure the athlete&#39;s foot to the foot rest during the rowing operation. Such straps or shoes enable the athlete to pull the rigger simply by moving his or her feet towards the seat. Straps and shoes, attached to a foot rest of a rowing machine, are well known in the art, and are therefore not shown in the drawings. 
     The cords are visible, in part, in  FIGS. 2-4 . The cords comprise means for transmitting energy from the oars to a pair of flywheels  11 . The flywheels are affixed to the frame, and do not translate relative to the frame. That is, the motion of the flywheels is entirely rotational, and not translational. The purpose of the flywheels is to provide resistance to the rowing stroke, so as to simulate the experience of actual rowing. More details of the arrangement of the cords are given later. 
     Monitor  13  may be mounted on the frame, through flexible mount  14 , for the purpose of providing feedback to the athlete regarding the progress of the rowing activity. One type of such feedback could include information about whether the simulated boat is turning. To provide such feedback, the flywheels can be connected to encoders, or their equivalents, and the angular displacements, or velocities, or both, of the flywheels can be calculated by a computer, and compared. If the flywheels are turning at different rates, the computer can be programmed to indicate, either graphically or numerically, or both, through monitor or display screen  13 , that the simulated boat is not traveling along a straight line. 
       FIG. 4  also shows oar leveler  12 , which is optionally included with the oars. The oar leveler comprises a piston and cylinder combination which adjusts the orientation of the oar relative to underframe arm  19 . 
       FIG. 5  shows the rowing trainer of the present invention, with an athlete using the device. The view shown is generally similar to that of  FIG. 3 . The athlete sits on the seat, and grasps the ends of the oars, while pushing on the foot rest with his or her feet. 
     The rowing trainer of the present invention is shown further in the top view of  FIG. 6  and the cross-sectional view of  FIG. 7 .  FIG. 6  clearly illustrates frame  1 , seat  3 , rigger  7 , oars  8  and  9 , foot rest  5 , and flywheels  11 . 
       FIG. 8  provides a bottom view of the rowing trainer of the present invention, and provides a more complete view of the arrangement of the cords. As shown in  FIG. 8 , cords  15  and  17  are affixed, at one end, to the free ends of underframe arms  19 , which arms are pivotally connected, through vertical links, to be described later, to the respective oars. The cords pass around castering pulleys  23  and  25 , the castering pulleys being attached to the rigger. The castering pulleys thus translate with the rigger. The cords then pass around flywheel pulleys or sprockets  27  and  29 , and then extend substantially the length of the frame, where they are connected to the frame through springs  31  and  33 . The spring could be replaced by a block and tackle mechanism using a bungee cord. 
       FIG. 9  illustrates the transmission portion of the rowing trainer of the present invention. In particular,  FIG. 9  shows the path of the cords, as they extend from the free ends of the underframe arms, around the castering pulleys, around the flywheel pulleys, and along the length of the frame (the frame being omitted in  FIG. 9 ) to the springs. 
       FIG. 10  provides a perspective view of the frame of the rigger  7 . The rigger frame includes a generally rectangular portion  61 , a pair of outwardly extending arms  62 , and a pair of hollow tubes  63 , the tubes being rigidly affixed to the arms  62 . The rectangular portion  61  is the component of the rigger which comprises means for engaging the frame. 
     The frame of the rigger is intended to be a single, rigid component. In practice, it may be formed of various pieces that are welded together, like a bicycle frame. 
       FIG. 11  provides a perspective view, showing the rigger and the oars, as well as foot rest  5 .  FIG. 12  provides a detail showing oar  9  and underframe arm  19  connected by vertical link  21 . The vertical link fits within tube  63 . In the other figures, such as in  FIGS. 2-5 , the vertical links are not visible, as they are entirely contained within tubes  63 . 
     Because the rigger frame is a rigid structure, the angle formed by the arms  62 , relative to the rectangular portion  61 , is fixed. Thus, throughout the rowing stroke, the tubes, and thus the vertical links, are located at a fixed position relative to the rigger, and translate back and forth with the motion of the rigger. 
     As the sliding rigger translates, the athlete is pulling on the grip portions of the oars, and the work applied to the grip portions rotates the vertical links  21 . The vertical links cause movement of underframe arms  19 , such that the underframe arms move at substantially the same angular velocity as the oars. The underframe arms pull the cords which are looped around the castering pulleys, thereby redirecting tension in the cords to the flywheel pulleys, thus rotating the flywheels. 
       FIGS. 13   a  and  13   b  provide perspective and top views, respectively, of the rowing trainer of the present invention in the “catch” position.  FIGS. 14   a  and  14   b  provide perspective and top views, respectively, of the rowing trainer of the present invention in the “drive” position. During the “drive” stroke, the sliding rigger moves away from the seat, the seat being stationary with respect to the frame.  FIGS. 15   a  and  15   b  provide perspective and top views, respectively, of the rowing trainer of the present invention in the “finish” position. 
       FIG. 16  provides a perspective view of an alternative embodiment of the rowing trainer of the present invention, wherein there is only one oar. In this embodiment, the oar is bigger than the oars in the two-oared embodiment, as it is intended that the athlete place two hands on this single oar. But the device otherwise operates in substantially the same way as the two-oared embodiment. 
     In either or both of the single-oar and double-oar embodiments of the present invention, the oar can be provided with the oar handle described in U.S. Pat. No. 6,126,500, the disclosure of which is incorporated by reference herein. 
       FIG. 17  provides a block diagram of the circuitry used for monitoring the performance of the athlete using the rowing trainer of the present invention. Flywheels  51  and  52  are connected, respectively, to encoders  53  and  54 , which encode the angular displacements of the flywheels, and provide such data to microprocessor  55 . The microprocessor is programmed to compare the data taken from the two encoders, and to present these data on display  56 . Display  56  is the same as monitor  13  shown in the other figures. 
     The rowing trainer of the present invention therefore provides a device in which 1) the moving mass is minimized, 2) the oars realistically simulate the motion of oars in a boat, and 3) the seat is stationary. The moving mass is minimized, in part, by making both the seat and the flywheels stationary relative to the frame. It is only the rigger and oar assembly which slides back and forth. 
     The flywheel system of the present invention is illustrated as including a relatively massive wheel and a “squirrel cage” fan. Flywheels used in the prior art have included fans, as well as magnetic, fluid, and/or frictional resistance. The flywheels used in the present invention can be made with any or all of the foregoing constructions. 
     The rowing trainer of the present invention may be provided with covers (not shown) on the flywheels and cables to prevent injury, i.e. to prevent items of clothing, or body parts, from becoming caught in the moving parts of the device. 
     The rowing trainer of the present invention can be modified in various ways, as will be understood by the reader skilled in the art. For example, the transmission of energy from the oars to the flywheels could be varied. The parameters displayed on the monitor could be changed. The microprocessor could be programmed to provide a very detailed graphical and/or numerical summary of the movements of the simulated boat. All of the above modifications should be considered within the spirit and scope of the following claims.