Exercise bicycle for exercising arms and legs

An exercise bicycle has a wheel axle which is journalled on a frame. Two swing arms are secured to two opposite end portions of the wheel axle. Two hand operated swing levers are mounted pivotally on the frame at their lower ends. Each of the levers includes an upper lever portion, a lower lever portion, and two parallel rods interconnecting the upper and lower lever portions for defining a slide slot therebetween. Each of the swing arms has a crank pin member on which a sheave is sleeved rotatably. Each of the sheaves has an annular groove of a generally V-shaped cross-section which engages with the arcuated inner side portions of the rods so that the sheave can slide smoothly in the slide slot. A suspended wheel is sleeved rotatably on the wheel axle by a hub. A front pulley is sleeved rigidly on the hub and is connected to a rear pulley by a v-belt. The rear pulley can be indirectly rotated by a user's hands and/or feet.

BACKGROUND OF THE INVENTION 
This invention relates to an exercise bicycle, and more particularly to one 
which has a suspended wheel, the suspended wheel being indirectly 
rotatable by hands and/or feet. 
Although the exercise bicycle of Application Ser. No. 192,166 can offer a 
significant exercise effect to the user, it is noisy due to the fact that 
much noise exists between rotating sprockets and chains and between 
sliding rollers and swinging levers. 
SUMMARY OF THE INVENTION 
The main object of this invention is to provide an exercise bicycle for 
exercising arms and legs which can smooth the relative sliding movement 
between rollers and swing levers. 
Another object of this invention is to provide an exercise bicycle for 
exercising the arms and legs which can reduce noise in comparison with the 
exercise bicycle of application Ser. No. 192,166. 
According to this invention, an exercise bicycle has a wheel axle which is 
journalled on a frame. Two swing arms are secured to two opposite end 
portions of the wheel axle. Two hand operated swing levers are mounted 
pivotally on the frame at their lower ends. Each of the levers includes an 
upper lever portion, a lower lever portion, and two parallel rods 
interconnecting the upper and lower lever portions for defining a slide 
slot therebetween. Each of the swing arms has a crank pin member on which 
a sheave is sleeved rotatably. Each of the sheaves has an annular groove 
of a generally V-shaped cross-section which engages with the arcuated 
inner side portions of the rods so that the sheave can slide smoothly in 
the slide slot. Preferably, the sheaves are made of plastic, steel or 
nylon. A suspended wheel is sleeved rotatably on the wheel axle by a hub. 
A front pulley is sleeved rigidly on the hub and is connected to a rear 
pulley by a v-belt. The rear pulley can be indirectly driven by hands 
and/or feet. The v-belt may be made of polyurethane. To minimize the noise 
resulting from the engagement of two sprockets and a chain, a tensioning 
sprocket is biased by a spring to tension the chain.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIGS. 1 and 2, an exercise bicycle of this invention includes 
a frame assembly 10, a foot drive assembly 20, a driven shaft assembly 30, 
a wheel axle assembly 40, a swing lever assembly 50, and a driven wheel 
assembly 60. 
The frame assembly 10 has a base frame 11 on which a driven wheel frame 12 
and a seat frame 13 are fixed. The wheel frame 12 and the seat frame 13 
are coupled by a strut 14. A front bearing block 15 is provided at the 
juncture between the wheel frame 12 and the strut 14. A rear bearing block 
16 is provided at the juncture between the seat frame 13 and the strut 14. 
A saddle 17 is supported on the seat frame 13. 
The foot drive assembly 20 includes a driving shaft 21 journalled on the 
bearings of the rear bearing block 16. The driving shaft 21 includes a 
rear driving sprocket 22 sleeved rigidly thereon, and two crank arms 23 
secured to respective ends of the driving shaft 21. Each of the crank arms 
23 carries a pedal 24 on the end thereof. 
As shown more clearly in FIG. 2, the driven shaft assembly 30 includes a 
driven shaft 31 which is journalled on the middle of the base frame 11. 
The driven shaft 31 includes a foot driven sprocket 32 sleeved rotatably 
on the right portion thereof, a hand driven sprocket 33 sleeved rotatably 
on the middle portion of the driven shaft 31, and a rear pulley 34 sleeved 
rigidly on the driven shaft 31. A foot driven chain 35 is trained on the 
rear driving sprocket 22 and the foot driven sprocket 32. To minimize the 
noise resulting from the engagement of the chain 35 and the sprockets 22, 
32, a tensioning sprocket 36 is mounted rotatably on the strut 14 by a 
connecting arm 37 and is biased by a spring 38 to tension the foot driven 
chain 35. 
Referring to FIG. 5, a first spring-biased ratchet mechanism is provided 
between the foot driven sprocket 32 and the driven shaft 31 in a known 
manner so that, when the foot driven sprocket 32 is rotated clockwise by 
stepping on the pedals 24, it is locked on the driven shaft 31 by the 
first ratchet mechanism and thus also rotates clockwise. When the foot 
driven sprocket 32 is rotated counterclockwise, the first ratchet 
mechanism is released to unlock the driven shaft 31 from the foot driven 
sprocket-32. With the first ratchet mechanism provided between the foot 
driven sprocket 32 and the driven shaft 31, the foot driven sprocket 32 
can be driven by the driven shaft 31 only when the driven shaft 31 rotates 
counterclockwise. However, the driven shaft 31 cannot drive the foot 
driven sprocket 32 due to the fact that the driven shaft 31 never rotates 
counterclockwise, as described hereinafter. 
Referring to FIG. 6, a second ratchet mechanism is provided between the 
hand driven sprocket 33 and the driven shaft 31 to perform the same 
function as the first ratchet mechanism. Therefore, both the foot driven 
sprocket 32 and the hand driven sprocket 33 act as the power input 
sprockets of the driven shaft 31. Because the rear pulley 34 is sleeved 
rigidly on the driven shaft 31, it can be driven by the same and can thus 
act as a power output pulley. As a result, because the driven shaft 31 can 
rotate only when either the foot driven sprocket 32 or the hand driven 
sprocket 33 is rotated clockwise, the driven shaft 31 can only rotate 
clockwise and cannot drive the foot driven sprocket 32 and/or the hand 
driven sprocket 33. As another result of providing these ratchet 
mechanisms, when a first torque is applied to the driven shaft 31 through 
the foot driven sprocket 32 and a second torque is applied to the driven 
shaft 31 through the hand driven sprocket 33, the sum of the first and 
second torques is output from the driven shaft 31 through the rear pulley 
34. 
The wheel axle assembly 40 includes a wheel axle 41 journalled on axle 
bearings 150 which are mounted within the front bearing block 15. A front 
driving sprocket 42 is sleeved rigidly on the wheel axle 41. A hand driven 
chain 43 is trained on the front driving sprocket 42 and the hand driven 
sprocket 33. Two swing arms 44 are sleeved on respective ends of the wheel 
axle 41. The wheel axle 41 has a left key-way 410 formed in its left end 
portion, and two opposed second key-ways 411 formed in the opposite sides 
of the right end portion of the wheel axle 41. The left swing arm 44 has a 
key 45 projecting therefrom to engage with the left key-way 410. The right 
swing arm 44 may be rotated relative to the wheel axle 41 to engage either 
of the right key-ways 411 with the key 45. Accordingly, the swing arms 44 
may be freely adjusted to locate on opposite sides or the same side of the 
wheel axle 41. When the swing arms 44 are on opposite sides of the wheel 
axle 41, they can be swung by hand in opposite directions. When the swing 
arms 44 are on the same side of the wheel axle 41, they can be swung by 
hand in the same direction. The two manners in which the swing arms 44 are 
actuated can be selected according to the preference of the user. Because 
the swing arms 44 may be actuated in two manners, the exercise effect of 
the bicycle is increased. Each of the swing arms 44 includes a crank pin 
member 440 connected securely thereto and can rotate an angle smaller than 
180 degrees. 
Referring to FIG. 3, two butted rollers 46 are sleeved rotatably on the 
crank pin member 440 and have a large-diameter portion, a small-diameter 
portion, and a tapered shoulder 460 interconnecting the large-diameter and 
small-diameter portions so as to define an annular groove of a generally 
V-shaped cross-section between the rollers 46. The butted rollers 46 look 
like a sheave. To keep the rollers 46 in a quiet and smooth rolling 
condition, the rollers 46 are preferably made of plastic, steel or nylon. 
The crank pin member 440 has an annular groove 441 in the end portion 
thereof. A retaining ring 48 is sleeved on the crank pin member 440 and 
engaged with the annular groove 441 so as to retain the rollers 46 and a 
washer 47 on the crank pin member 440. 
The swing lever assembly 50 consists of two swing levers each of which 
includes an upper lever portion 50', a lower lever portion 50", a grip 51, 
a lower end sleeve 52 sleeved rotatably on a pivot pin 110 which is fixed 
on the base frame 11, and two cylindrical rods 53 interconnecting the 
upper lever portion 50' and the lower lever portion 50" for defining a 
slide slot 54 therebetween. It is understood that no tool is needed when 
the rollers 46 are coupled with both the crank pin member 440 and the 
swing lever. The inner side portions of the rods 53 are engaged with the 
annular groove of the sheave or the tapered shoulders 460 of the rollers 
46 so that the crank pin member 440 can slide smoothly in the slide slot 
54 of the swing lever. A shield 55 is in the form of a semi-cylinder and 
has a top wall 550 in which a retaining groove 551 is formed. The 
retaining groove 551 of the shield 55 is engaged with the upper lever 
portion 50' of the swing lever. The bottom wall of the shield 55 is 
retained on the lower lever portion 50" of the swing lever in the same 
manner in which the top wall 550 is retained on the upper lever portion 
50'. 
Alternatively, referring to FIG. 4, the rollers 46 may be replaced with a 
sheave 49 which is connected pivotally on a rotating wheel 491. The slide 
slot 54' of the swing lever has an enlarged upper end 540 through which 
the sheave 49 is inserted into the slide slot 54'. It should also be 
stressed that, when the sheave 449 is coupled with the swing lever, no 
tool is needed. The sheave 49 can only slide in the slide slot 54' below 
the enlarged upper end 540 when the levers are swung. 
The wheel assembly 60 includes a wheel hub 61, and a driven wheel 62 
sleeved rigidly on the wheel hub 61. The wheel hub 61 is sleeved rotatably 
on the wheel axle 41 by hub bearings 63 and includes a front pulley 64 
sleeved rigidly on the wheel hub 61. A v-belt 65 is engaged with the 
V-shaped grooves of both the rear pulley 34 and the front pulley 64. In 
this embodiment, to increase lifetime and reduce noise, the v-belt 65 is 
made of polyurethane. The driven wheel 62 is enclosed by a net shield, 
(not shown), in a known manner. 
When the pedals 24 are propelled forward, the power is transferred to the 
wheel 62 through the transmission line of the crank arms 23, driving shaft 
21, rear driving sprocket 22, foot driven chain 35, foot driven sprocket 
32, driven shaft 31, rear pulley 34, v-belt 65, front pulley 64 and hub 
61. 
When the levers 51 are swung manually to and fro, the power is transferred 
to the wheel 62 through the transmission line of the swing arms 44, wheel 
axle 41, front driving sprocket 42, hand driven chain 43, hand driven 
sprocket 33, driven shaft 31, rear pulley 34, v-belt 65, front pulley 64 
and hub 61. 
With this invention thus explained, it is apparent that numerous 
modifications and variations can be made without departing from the scope 
and spirit of this invention. It is therefore intended that this invention 
be limited only as indicated in the appended claims.