Patent ID: 9114276
Filing Date: 2015-08-25
Classification: A63B

Abstract:
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 front pulley coupled to the front shaft; a rear shaft rotatably coupled to the treadmill frame at the rear end; a rear pulley coupled to the rear shaft; a running belt contacting the front and rear pulleys and 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 a first force generated by a 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; a synchronizing system coupled to both the front and rear shafts, the synchronizing system comprising a synchronizing belt coupled between the front and rear shafts, wherein tension in the synchronizing belt provides a second force which acts to resist differential rotation of the front and rear shafts; and 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.