Arm lever for an exercise bicycle

An arm lever for an exercise bicycle has a pivot portion to be mounted pivotally on a front end portion of a bicycle frame and a bottom end to be connected to an end of a crank arm. The bottom end of the arm lever is provided with a locking plate which has a forked extension with a distal bottom end, an upright slit that opens from the distal bottom end, and a plurality of spaced locking holes that extend through the slit. The slit permits the extension of the end of the crank arm therein. The forked extension is connected to the crank arm at a selected one of the locking holes to vary the distance of the end of the crank arm from the pivot portion and vary correspondingly the range of pivoting movement of the arm lever to suit the user's physique.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention relates to an exercise bicycle, more particularly to an 
improved arm lever construction for an exercise bicycle, 
2. Description of the Related Art 
Referring to FIG. 1, a conventional exercise bicycle 10 is shown to 
comprise a frame 11, a foot pedal assembly 12, a reciprocating arm 
assembly 13, a resistance wheel 14, and a transmission system 15. 
The transmission system 15 includes a drive shaft 121 mounted rotatably on 
a rear end portion of the frame 11, and a pair of eccentric arms 122 
mounted securely on two ends of the drive shaft 121 (only one eccentric 
arm 122 is shown). The foot pedal assembly 12 includes a pair of foot 
pedal cranks 123 mounted on a distal end of a respective one of the 
eccentric arms 122 (only one foot pedal crank 123 is shown). The 
reciprocating arm assembly 13 includes a pair of reciprocating arm levers 
131 mounted pivotally on a front end portion of the frame 11 on two sides 
of the latter, and a pair of crank arms 132 (only one of the arm levers 
131 and the crank arms 132 is shown). Each of the crank arms 132 has a 
first end connected to the distal end of a respective one of the eccentric 
arms 122 and a second end connected pivotally to a lower end of a 
respective one of the arm levers 131. Thus, operation of the foot pedal 
cranks 123 results in forward and rearward movement of the crank arms 132 
to produce reciprocating movement of the arm levers 131. 
The resistance wheel 14 is mounted rotatably on the front end portion of 
the frame 11 between the arm levers 131. The transmission system 15 is 
used to link the foot pedal cranks 123 to the resistance wheel 14, thus 
permitting the rotation of the resistance wheel 14 when the foot pedal 
cranks 123 are operated. When the arm levers 131 are oscillated, the crank 
arms 132 cause the drive shaft 121 to rotate, thereby similarly driving 
the transmission system 15 to rotate the resistance wheel 14. The 
conventional exercise bicycle can thus be used to exercise the upper and 
lower parts of the body. Referring to FIG. 2, the range of pivoting 
movement of the arm levers 131 is fixed and cannot be varied so as to suit 
the physique of the user. For example, if the user has long hands, it is 
quite possible that the hands of the user are not fully stretched when the 
arm levers 131 reach the front limit of the pivoting range. This often 
results in fatigue, poor exercise results and can affect the user's 
interest in using the conventional exercise bicycle 10. If the user has 
short hands, it is possible that the user has to lean forward in order to 
move the arm levers 131 to the front limit of the pivoting range. This can 
also cause the user to tire easily. 
SUMMARY OF THE INVENTION 
Therefore, the objective of the present invention is to provide an improved 
arm lever construction for an exercise bicycle which can permit 
adjustments in the range of pivoting movement of the same so as to suit 
the physique of a user. 
Accordingly, the arm lever of the present invention is to be used in an 
exercise bicycle which includes a frame, a drive shaft mounted rotatably 
on a rear end portion of the frame, and a crank arm with a first end 
connected eccentrically to one end of the drive shaft and a second end. 
The arm lever has a top end, a bottom end and an intermediate pivot 
portion between the top and bottom ends. The pivot portion is to be 
mounted pivotally on a front end portion of the frame. The bottom end of 
the arm lever is to be connected to the second end of the crank arm and is 
provided with a locking plate. The locking plate has a forked extension 
with a distal bottom end and an upright slit which opens from the distal 
bottom end. The forked extension is further formed with a plurality of 
spaced locking holes which extend through the slit and which are arranged 
along a curved line. The slit permits the extension of the second end of 
the crank arm therein. The forked extension is connected to the second end 
of the crank arm at a selected one of the locking holes to vary the 
distance of the second end of the crank arm from the pivot portion and 
vary correspondingly the range of pivoting movement of the arm lever.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 3 illustrates an exercise bicycle which incorporates a pair of arm 
levers 30 (only one arm lever 30 is shown) according to a first preferred 
embodiment of the present invention. The exercise bicycle comprises a 
frame 20 and a reciprocating arm assembly, which includes the arm levers 
30 and a pair of crank arms 40, mounted on the frame 20. A drive shaft 21 
is mounted rotatably on a rear end portion of the frame 20, and a pair of 
eccentric arms 22 are mounted securely on two ends of the drive shaft 21 
(only one eccentric arm 22 is shown). Each of the crank arms 40 has a 
first end connected to a distal end of a respective one of the eccentric 
arms 22 and a second end connected to a bottom end of a respective one of 
the arm levers 30. The arm levers 30 are disposed on two sides of a front 
end portion of the frame 20. 
Referring to FIG. 4, the bottom end of the arm lever 30 is provided with a 
locking plate 31. In this embodiment, the locking plate 31 has a forked 
extension 311 which curves rearwardly. The forked extension 311 has an 
upright slit 32 which opens from a distal bottom end thereof. The forked 
extension 311 is further formed with a plurality of spaced locking holes 
33 which extend through the slit 32 and which are disposed along a curved 
line. In this embodiment, there are two locking holes 331, 332. The arm 
lever 30 further has a top end which is formed with a hand grip portion 
34. 
Referring once more to FIG. 3, the second end of each crank arm 40 extends 
into the slit 32 of the forked extension 311 of the respective arm lever 
30. A locking pin 41 is inserted into a selected one of the locking holes 
331, 332 so as to connect pivotally the crank arm 40 to the respective arm 
lever 30. 
The phantom lines of FIG. 5 illustrate one of the crank arms 40 when 
connected to the respective arm lever 30 at the upper locking hole 331. 
When it is desired to connect the crank arm 40 to the respective arm lever 
30 at the lower locking hole 332, it is preferable to pivot the arm lever 
30 to the rear limit of the pivoting range before removing the locking pin 
41. The crank arm 40 is movable within the slit 32 when the respective 
locking pin 41 is removed. At this stage, since the locking holes 331, 332 
lie along the path of movement of the second end of the crank arm 40, the 
crank arm 40 can be easily connected to the arm lever 30 at the lower 
locking hole 332. 
Each arm lever 30 has an intermediate pivot portion 35 disposed between the 
hand grip portion 34 and the locking plate 31 for mounting pivotally the 
arm lever 30 on the front end portion of the frame 20. When the arm lever 
30 is oscillated, forward and rearward movement of the respective crank 
arm 40 occurs so as to cause rotation of the drive shaft 21. Since linear 
movement of the crank arm 40 is limited by the displacement of the first 
end of the crank arm 40 from the drive shaft 21, the range of pivoting 
movement of the hand grip portion 34 of the arm lever 30 is also affected 
thereby. 
Referring to FIG. 6, when the second end of the crank arm 40 is connected 
to the lower locking hole 332, a smaller range of pivoting movement by the 
arm lever 30 is permitted because the second end of the crank arm 40 is 
disposed farther from the pivot portion 35. Whereas, when the second end 
of the crank arm 40 is connected to the upper locking hole 331, a larger 
range of pivoting movement by the arm lever 30 is permitted because the 
second end of the crank arm 30 is disposed closer to the pivot portion 35 
(as shown by the phantom lines). 
Before using an exercise bicycle which incorporates the arm lever 30 of the 
present invention, it is necessary to adjust the connection between the 
arm levers 30 and the crank arms 40 in order to suit the length of one's 
arms. If the user's arms are short, the crank arms 40 are connected to the 
arm levers 30 at the lower locking hole 332 in order to reduce the range 
of pivoting movement by the arm levers 30, thereby obviating the need for 
the user to lean forward when moving the arm levers 30 to the front limit 
of the pivoting range. If the user's arms are long, the crank arms 40 are 
connected to the arm levers 30 at the upper locking hole 331 in order to 
increase the range of pivoting movement by the arm levers 30, thereby 
ensuring that the arms of the user can be stretched fully when the arm 
levers 30 are oscillated. 
FIG. 7 illustrates the second preferred embodiment of an arm lever 50 for 
an exercise bicycle in accordance with the present invention. The arm 
lever 50 also has a bottom end which is provided with a locking plate 51. 
In this embodiment, the locking plate 51 has a forked extension 511 which 
is L-shaped in cross-section and which has an upright slit 52 that opens 
from a distal bottom end thereof. The forked extension 511 is further 
formed with three spaced locking holes 53 which extend through the slit 52 
and which are arranged along a curved line. As with the previous 
embodiment, one end of a crank arm (not shown) extends into the slit 52 of 
the forked extension 511 and can be connected pivotally to the arm lever 
50 at a selected one of the locking holes 53. 
It has thus been shown that the shape of the forked extension is 
unimportant, as long as a plurality of locking holes may be formed 
therethrough in a curved line arrangement. 
While the present invention has been described in connection with what is 
considered the most practical and preferred embodiments, it is understood 
that this invention is not limited to the disclosed embodiments but is 
intended to cover various arrangements included within the spirit and 
scope of the broadest interpretation so as to encompass all such 
modifications and equivalent arrangements.