Patent Publication Number: US-2013237379-A1

Title: Pedal lifting mechanism for elliptical trainer

Description:
BACKGROUND OF THE INVENTION  
     1. Field of the Invention 
     The present invention relates to elliptical trainers and more particularly, to a pedal lifting mechanism for an elliptical trainer. 
     2. Description of the Related Art 
     An elliptical trainer is a well-developed cardio-respiratory fitness exercise machine for shuffling the feet back and forth within the elliptically shaped paths to simulate walking, running, or stair climbing for achieving the purpose of exercising leg and thigh muscles. However, the conventional elliptical trainer has a monotonous operation because the pedals are moved along fixed paths, such that the conventional elliptical trainer can only be used to exercise the specific parts of the leg and thigh muscles. 
     Taiwan Patent No. I294294 discloses an elliptical trainer, comprising two pedals, a guide track bracket, and an inclination adjusting device. The inclination adjusting device includes a screw rod, a nut member screwingly coupled to the screw rod so as to be moved by the rotary motion of the screw rod, and a support rod connected with the screw member so as to be biased by the actuation of the nut member. Thus, when the support rod is biased, the guide track bracket can be controlled by the support rod to change the angle relative to the ground, thereby adjusting the slope of the pedals. Besides, Taiwan Patent No. M403355 discloses a lift device for an elliptical trainer, comprising a driver and a lift bracket pivotally connected with a retractable rod of the driver, such that the lift bracket can be biased by the driver to adjust the angle relative to the ground for changing the slope of the pedals. 
     According to the aforesaid prior arts, the inclination adjusting device or the lift device is difficult to be assembled within a limited space, and therefore this problem may lead to a complicated structure and high manufacturing cost. 
     SUMMARY OF THE INVENTION  
     The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a pedal lifting mechanism for an elliptical trainer, which is simple in structure and easy to be assembled, and has low manufacturing cost. 
     To achieve this object of the present invention, a pedal lifting mechanism for an elliptical trainer comprises a base for being placed on a support surface, a lift bracket having a rear end pivotally connected with the base, and an inclination adjusting device including a driver mounted on the base and spaced from a front end of the lift bracket, a driving rod having a front end connected with the driver to be changed in length through the actuation of the driver, and a frame pivotally connected with the front end of the lift bracket and a rear end of the driving rod so as to drive the lift bracket to bias upwards and downwards relative to the base through the actuation of the driving rod. By means of the biasing motion of the lift bracket upwards and downwards relative to the base, the paths of two pedals which are supported on the lift bracket can be changed to achieve the purpose of exercising different parts of the leg and thigh muscles; and further, by means of the space arrangement between the lift bracket and the inclination adjusting device, the structure of the pedal lifting mechanism can be simplified, and the manufacturing cost of the pedal lifting mechanism can be reduced. 
     Preferably, the lift bracket includes two lift tubes located at the left and right sides of the base, a bridge coupled between the front ends of the lift tubes and pivotally connected with the support frame, and a connecting tube connected with the rear ends of the lift tubes and provided with two ends pivotally connected with the base. 
     Preferably, the driving rod has a screw rod having one end connected with the driver so as to be rotated by the driver, and a sleeve screwed to the screw rod and pivotally connected with the frame so as to be movable along an axial direction of the screw rod by a rotary motion of the screw rod for enabling the driving rod to change its length. 
     Preferably, the frame includes a main rod pivotally connected between the front end of the lift bracket and the rear end of the driving rod, a shaft connected with the bottom end of the main rod, and two rollers rotatably connected with two ends of the shaft and abutted against the support surface, thereby enhancing the structural stabilization. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         FIG. 1  is a perspective view of an elliptical trainer equipped with a pedal lifting mechanism according to a preferred embodiment of the present invention; 
         FIG. 2  is a perspective view of the pedal lifting mechanism according to the preferred embodiment of the present invention; 
         FIG. 3  is a lateral view of the elliptical trainer, showing the lift bracket isn&#39;t raised; 
         FIG. 4  is an enlarged view of parts of the elliptical trainer of  FIG. 3 , showing the lift bracket isn&#39;t raised; 
         FIG. 5  is another lateral view of the elliptical trainer, showing the lift bracket is raised; and 
         FIG. 6  is an enlarged view of parts of the elliptical trainer of  FIG. 5 , showing the lift bracket is raised. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     As shown in  FIG. 1 , an elliptical trainer  10  equipped with a pedal lifting mechanism  20  in accordance with a preferred embodiment of the present invention comprises a main frame  12 , a flywheel set  14 , two pedal sets  16 , and two handles  18 . Since the elliptical trainer  10  is a well-known exercise machine, the structures of and the relationships among the aforesaid components aren&#39;t further detailedly described hereunder. As shown in  FIG. 2 , the pedal lifting mechanism  20  in accordance with the preferred embodiment of the present invention comprises a base  30 , a lift bracket  40 , and an inclination adjusting device  50 . 
     The base  30  is used to be placed on a support surface G (such as the ground) for installation of the main frame  12  of the elliptical trainer  10 . 
     The lift bracket  40  includes two lift tubes  42  located at the left and right sides of the base  30  for engagement of the pedal sets  16 , a bridge  44  having two ends respectively coupled to the front ends of the lift tubes  42 , and a connecting tube  46  connected with the rear ends of the lift tubes  42  and provided with two ends pivotally connected with two L-shaped lugs  32  of the base  30 . After the pedal lifting mechanism  20  is assembled, as shown in  FIG. 4 , the lift bracket  40  is higher in elevation than the base  30 . 
     As shown in  FIGS. 4 and 5 , the inclination adjusting device  50  includes a driver  60 , a driving rod  70 , and a frame  80 . The driver  60  is mounted on the base  30  and spaced from the front end of the lift bracket  40 . A screw rod  72  provided by the driving rod  70  has one end connected with the driver  60  so as to be rotated by the actuation of the driver  60 , and a sleeve  74  provided by the driving rod  70  is screwed to the screw rod  72  so as to be movable along an axial direction of the screw rod  72  by the rotary motion of the screw rod  72 . The frame  80  includes a main rod  82  having a top end pivotally connected with the bridge  44  of the lift bracket  40  and a middle part pivotally connected with the rear end of the sleeve  74  of the driving rod  70 , a shaft  84  transversely connected with the bottom end of the main rod  82 , and two rollers  86  rotatably connected with two ends of the shaft  84  and abutted against the support surface G for enhancing the structural stabilization. 
     To adjust the paths of the pedal sets  16 , the driver  60  is operated to rotate the screw rod  72  of the driving rod  70  to drive the sleeve  74  of the driving rod  70  to move and push the frame  80 , such that the frame  80  is stably moved backwards as the rollers  86  roll backwards on the support surface G. During the movement of the frame  80 , the lift tubes  42  of the lift bracket  40  are pivotally moved upwards around the center of the connecting tube  46  to create a predetermined angle relative to the support surface G, as shown in  FIGS. 5 and 6 . As a result, the inclination angle of the pedal sets  16  is changed in response to the rise of the lift tube  42  of the lift bracket  40 , so that the pedal sets  16  can be forced by a pressure from the user&#39;s foot to move along different paths, thereby exercising different parts of the leg and thigh muscles. 
     As indicated above, since the inclination adjust device  50  and the lift bracket  40  are arranged in a front-back manner, the pedal lifting mechanism  20  of the present invention can be assembled with less necessary components and without space restrictions to achieve the purpose of simple structure, easy assembly, and low manufacturing cost. Further, when the pedal lifting mechanism  20  of the present invention is in use, the user can adjust the pedal sets  16  to a desired position for exercising according to actual needs. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.