Adjustable exercise bicycle

Abstract

An adjustable exercise bicycle includes a fixed frame, a seat, a movable frame, a locking device, a pedal device and an assisting device. The assisting device is arranged between the fixed frame and the movable frame. The assisting device is for forcing the movable frame and generating a first moment about the axis. The total weight of the movable frame and its loading generate a second moment about the axis. The resultant moment of the first moment and the second moment is a third moment which can move the movable frame from a second angle to a first angle when the movable frame is oriented at an unlocked state. The user can force the pedal device against the third moment for moving the movable frame from the first angle to the second angle.

What is claimed is: 
     
         1 . An adjustable exercise bicycle, comprising:
 a fixed frame;   a seat arranged on the fixed frame;   a movable frame pivotally coupled to the fixed frame about an axis for being swung between a first angle and a second angle;   a locking device located between the movable frame and the fixed frame for locking the movable frame at a chosen angle between the first angle and the second angle, the locking device having a control member arranged within reach of a user on the seat, the control member controlling the movable frame between a locked state and an unlocked state;   a pedal device pivotally coupled to the movable frame via a rotating shaft, the rotating shaft being at a first position when the movable frame is oriented at the first angle and at a second position when the movable frame is oriented at the second angle, the second position being more distant from the seat than the first position; and   an assisting device arranged between the fixed frame and the movable frame, the assisting device generating a first moment about the axis;   wherein a second moment about the axis is generated from the movable frame and the resultant moment of the first moment and the second moment is a third moment , the third moment being configured to be able to move the movable frame from the second angle toward the first angle when the movable frame is at the unlocked state.   
     
     
         2 . The adjustable exercise bicycle of  claim 1 , wherein the second position is at the lower front of the first position. 
     
     
         3 . The adjustable exercise bicycle of  claim 2 , wherein the top center of the seat and the rotating shaft define a straight line, the variation of an angle between the straight line and the horizontal plane being less than fifteen degrees in the lateral view when the movable frame is swung between the first angle and the second angle. 
     
     
         4 . The adjustable exercise bicycle of  claim 2 , wherein the rotating shaft is swung between the first position and the second position to form a swing track, the axis being located below the swing track. 
     
     
         5 . The adjustable exercise bicycle of  claim 1 , wherein the rotating shaft is swung between the first position and the second position to form a swing track, the axis being located below the swing track. 
     
     
         6 . The adjustable exercise bicycle of  claim 5 , wherein the direction of the second moment is the same as the direction of the first moment when the rotating shaft is oriented at the first position. 
     
     
         7 . The adjustable exercise bicycle of  claim 5 , wherein the direction of the second moment is opposite to the direction of the first moment when the rotating shaft is oriented at the second position. 
     
     
         8 . The adjustable exercise bicycle of  claim 1 , wherein the rotating shaft is swung between the first position and the second position to form a swing track, the position of the axis being higher than the position of the swing track. 
     
     
         9 . The adjustable exercise bicycle of  claim 1 , wherein the assisting device is a gas spring having two ends which are pivotally coupled to the fixed frame and the movable frame respectively. 
     
     
         10 . The adjustable exercise bicycle of  claim 1 , the locking device further comprising:
 a positioning frame arranged on the fixed frame and having several positioning holes which are arranged along a first direction, each positioning hole having a first hole wall and a second hole wall;   a restricted frame arranged on the movable frame and configured to be swung between the first angle and the second angle along the first direction, the restricted frame having a first resisting portion and a second resisting portion;   a linkage member selectively moveable between a locked position which is near the positioning frame and an unlocked position which is far from the positioning frame along a second direction, the control member being configured to move the linkage member from the locked position to the unlocked position;   at least one elastic member coupled between the restricted frame and the linkage member and pushing the linkage member toward the positioning frame;   a first pin pivotally coupled to the linkage member and comprising:
 a first guiding plane oriented at one end of the first pin which is near the positioning frame and being not parallel nor perpendicular to the second direction, the first guiding plane engaging with the first hole wall of the positioning hole when the linkage member is oriented at the locked position; and 
 a first pressed portion being far from the positioning frame than the first guiding plane, the first pressed portion engaging with the first resisting portion when the linkage member is oriented at the locked position; and 
   a second pin pivotally coupled to the linkage member and comprising:
 a second guiding plane oriented at one end of the second pin which is near the positioning frame and being not parallel nor perpendicular to the second direction, the second guiding plane engaging with the second hole wall of the positioning hole when the linkage member is oriented at the locked position; and 
 a second pressed portion being far from the positioning frame than the second guiding plane, the second pressed portion engaging with the second resisting portion when the linkage member is oriented at the locked position. 
   
     
     
         11 . The adjustable exercise bicycle of  claim 10 , wherein the first guiding plane and the second guiding plane are beveled. 
     
     
         12 . The adjustable exercise bicycle of  claim 10 , wherein the first guiding plane engages with the first hole wall of one of the positioning holes and the second guiding plane engages with the second wall hole of another positioning hole which is near the foregoing positioning hole when the linkage member is oriented at the locked position. 
     
     
         13 . The adjustable exercise bicycle of  claim 10 , wherein the second guiding plane is face to the first guiding plane. 
     
     
         14 . The adjustable exercise bicycle of  claim 10 , wherein the second guiding plane is opposite to the first guiding plane.