Manual treadmill and methods of operating the same

Abstract

A manually operated treadmill and methods of using the same are provided. The treadmill includes a treadmill frame having a front end and a rear end opposite the front end, a front shaft rotatably coupled to the treadmill frame at the front end, a rear shaft rotatably coupled to the treadmill frame at the rear end, and a running belt including a curved running surface upon which a user of the treadmill may run. The running belt is disposed about the front and rear shafts such that force generated by the user causes rotation of the front shaft and the rear shaft and also causes the running surface of the running belt to move from the front shaft toward the rear shaft. The treadmill is configured to control the speed of the running belt to facilitate the maintenance of the contour of the curved running surface.

1 . A manually operated treadmill comprising:
 a treadmill frame having a front end and a rear end opposite the front end;   a front shaft rotatably coupled to the treadmill frame at the front end;   a rear shaft rotatably coupled to the treadmill frame at the rear end; and   a running belt including a curved running surface upon which a user of the treadmill may run, wherein the running belt is disposed about the front and rear shafts such that force generated by the user causes rotation of the front shaft and the rear shaft and also causes the running surface of the running belt to move from the front shaft toward the rear shaft;   wherein the treadmill is configured to control the speed of the running belt to facilitate the maintenance of the contour of the curved running surface.   
     
     
         2 . The manually operated treadmill of  claim 1 , wherein the front shaft is configured such that the speed of the running belt at the front shaft is greater than the speed of the running belt at the rear shaft. 
     
     
         3 . The manually operated treadmill of  claim 2 , further comprising:
 a front pulley coupled to the front shaft; and   a rear pulley coupled to the rear shaft;   wherein the running belt is supported by and contacts the front and rear pulleys, wherein the radius of the front pulley is greater than the radius of the rear pulley.   
     
     
         4 . The manually operated treadmill of  claim 3 , wherein the difference between the radius of the front pulley and the radius of the rear pulley is less than approximately 0.1 inches. 
     
     
         5 . The manually operated treadmill of  claim 3 , wherein the difference between the radius of the front pulley and the radius of the rear pulley is between approximately 0.005 and 0.035 inches. 
     
     
         6 . The manually operated treadmill of  claim 2 , further comprising a braking system configured to slow rotation of the rear shaft resulting in the greater speed of the running belt at the front shaft. 
     
     
         7 . The manually operated treadmill of  claim 1 , further comprising a synchronizing system coupled to both the front and rear shafts, wherein the synchronizing system is configured to provide a force that acts to resist differential rotation of the front and rear shafts. 
     
     
         8 . The manually operated treadmill of  claim 7 , further comprising:
 a front pulley coupled to the front shaft;   a rear pulley coupled to the rear shaft, wherein the running belt contacts the front and rear pulleys;   wherein the synchronizing system comprises a synchronizing belt coupled between the front and rear shafts, wherein tension in the synchronizing belt provides the force which acts to resist differential rotation of the front and rear shafts.   
     
     
         9 . The manually operated treadmill of  claim 8 , wherein the synchronizing system further comprises a front synchronizing pulley coupled to the front shaft and a rear synchronizing pulley coupled to the rear shaft, the synchronizing belt coupled between the front and rear synchronizing pulleys. 
     
     
         10 . The manually operated treadmill of  claim 7 , wherein the synchronizing system comprises a synchronizing shaft having a front portion and a rear portion, wherein the front portion interconnects with the front shaft and the rear portion interconnects with the rear shaft, and the simultaneously interconnected front and rear portions and front and rear shafts provide the force which acts to resist differential rotation of the front and rear shafts. 
     
     
         11 . The manually operated treadmill of  claim 7 , wherein the synchronizing system further comprises:
 a first gear including a toothed surface, the first gear coupled to the front shaft;   a second gear including a toothed surface, the second gear coupled to the rear shaft;   a first threaded surface disposed on the front portion of the synchronizing shaft, the first threaded surface engages the toothed surface of the first gear; and   a second threaded surface disposed on the rear portion of the synchronizing shaft, the second threaded surface engages the toothed surface of the second gear;   wherein the simultaneously engaged front and rear threaded portions and toothed surfaces provides the force which acts to resist differential rotation of the front and rear shafts.   
     
     
         12 . The manually operated treadmill of  claim 1 , wherein the treadmill is configured to prevent movement of the running surface of the running belt in a direction from the rear shaft toward the front shaft. 
     
     
         13 . The manually operated treadmill of  claim 1 , further comprising a one-way bearing assembly coupled to at least one of the front shaft and the rear shaft, wherein the one-way bearing assembly prevents rotation of at least one of the front shaft and the rear shaft in one direction and permits rotation of at least one of the front shaft and the rear shaft in the opposite direction to restrict rotation of the running belt in a single direction. 
     
     
         14 . The manually operated treadmill of  claim 1 , further comprising a manual elevation adjustment system configured to elevate the front end of the running belt, the manual elevation adjustment system comprising a hand crank that is rotated to raise and lower the front end of the running belt. 
     
     
         15 . The manually operated treadmill of  claim 1 , wherein the curved running surface comprising at least a convex curved section and a concave curved section, wherein the concave curved section is located between the front shaft and the convex curved section. 
     
     
         16 . A manually operated treadmill comprising:
 a treadmill frame;   a front support member rotatably coupled to the treadmill frame;   a rear support member rotatably coupled to the treadmill frame;   a running belt including a curved running surface upon which a user of the treadmill may run, wherein the running belt is supported by the front support member and the rear support member, wherein the force generated by the user causes rotation of the front support member and the rear support member and also causes the running belt to rotate relative to the treadmill frame; and   a synchronizing system configured to cause the front support member and the rear support member to rotate at substantially the same speeds.   
     
     
         17 . The manually operated treadmill of  claim 16 , further comprising:
 a front shaft rotatably coupled to the treadmill frame, wherein the front support member is coupled to the front shaft; and   a rear shaft rotatably coupled to the treadmill frame, wherein the rear support member is coupled to the rear shaft;   wherein the synchronizing system comprises a synchronizing belt coupled between the front and rear shafts, wherein tension in the synchronizing belt provides a force which acts to resist the front and rear shafts from rotating at different speeds.   
     
     
         18 . The manually operated treadmill of  claim 17 , wherein the synchronizing system further comprises a front synchronizing pulley coupled to the front shaft and a rear synchronizing pulley coupled to the rear shaft, the synchronizing belt coupled between the front and rear synchronizing pulleys. 
     
     
         19 . The manually operated treadmill of  claim 16 , wherein the synchronizing system comprises a synchronizing shaft having a front portion and a rear portion, wherein the front portion interconnects with the front support member and the rear portion interconnects with the rear support member, and further wherein the simultaneously interconnected front and rear portions and front and rear support members provides the force which acts to resist the front and rear support members from rotating at different speeds. 
     
     
         20 . The manually operated treadmill of  claim 19 , wherein the synchronizing system comprises:
 a first gear including a toothed surface, the first gear coupled to the front support member;   a second gear including a toothed surface, the second gear coupled to the rear support member;   a first threaded surface disposed on the front portion of the synchronizing shaft, the first threaded surface engages the toothed surface of the first gear; and   a second threaded surface disposed on the rear portion of the synchronizing shaft, the second threaded surface engages the toothed surface of the second gear;   wherein the simultaneously engaged front and rear threaded portions and toothed surfaces provides the force which acts to resist the front and rear support members from rotating at different speeds.   
     
     
         21 . The manually operated treadmill of  claim 16 , wherein the front support member is configured such that the speed of the running belt at the front support member is greater than the speed of the running belt at the rear support member. 
     
     
         22 . The manually operated treadmill of  claim 21 , wherein the front support member comprises a front pulley and the rear support member comprises a rear pulley, wherein the running belt is disposed around and contacts the front and rear pulleys, wherein the radius of the front pulley is greater than the radius of the rear pulley resulting in the greater speed of the running belt at the front support. 
     
     
         23 . A manually operated treadmill comprising:
 a treadmill frame;   a front shaft rotatably coupled to the treadmill frame;   a rear shaft rotatably coupled to the treadmill frame;   a running belt including a contoured running surface upon which a user of the treadmill may run, wherein the running belt is disposed about the front and rear shafts such that force generated by the user causes rotation of the front shaft and the rear shaft and also causes the running belt to rotate about the front shaft and the rear shaft without the rotation of the running belt being generated by a motor; and   a one-way bearing assembly configured to prevent rotation of the running surface of the running belt in one direction.   
     
     
         24 . The manually operated treadmill of  claim 23 , wherein the one-way bearing assembly is rotatably coupled to the rear shaft and coupled to the treadmill frame. 
     
     
         25 . The manually operated treadmill of  claim 23 , further comprising:
 at least one track supported by the treadmill frame, at least a portion of the at least one track substantially replicating at least a portion of the contoured running surface; and   a plurality of roller assemblies supporting the running belt, the plurality of roller assemblies being movably coupled to at least a portion of the at least one track so that the running belt may rotate relative to the at least one track and will follow a relative contour of at least a portion of the contoured running surface.   
     
     
         26 . The manually operated treadmill of  claim 23 , further comprising:
 at least one magnet supported by one of the treadmill frame and the running belt and the other of the treadmill frame and the running belt being magnetically attracted to the at least one magnet adjacent to the running surface so that the running belt substantially follows a contour of the contoured running surface.   
     
     
         27 . A manually operated treadmill comprising:
 a treadmill frame;   a running belt including a running surface upon which a user of the treadmill may run;   a front support member rotatably coupled to the treadmill frame, the front support member comprising the forwardmost support for the running belt; and   a rear support member rotatably coupled to the treadmill frame, the rear support member comprising the rearwardmost support for the running belt;   wherein the running surface comprises at least in part a complex curve located intermediate the front support member and the rear support member and incorporating a minimum of two geometric configurations.