Exercise machine making use of body weight of exerciser as load weight thereof

An exercise machine making use of the body weight of an exerciser as a load weight thereof comprises a base, a fixation rod member, an upper rocking bar member, a lower rocking bar member, an expandable connection bar member, a seat pad, a back pad, a handle, and a cushioning member. Unlike a conventional exercise machine, the exercise machine so disclosed is composed of no weights. The fixation rod member can be adjusted in accordance with the height of an exerciser. The length of the expandable connection rod member can be adjusted by adjusting the pivoting position of the upper rocking bar member or the length of the fixation rod member. The exerciser can use the machine by seating or standing on the seat pad of the machine for doing the muscle-building exercise.

FIELD OF THE INVENTION 
The present invention relates generally to an exercise machine, and more 
particularly to an exercise machine which makes use of the body weight of 
an exerciser as a load weight of the machine. 
BACKGROUND OF THE INVENTION 
The conventional exercise machine is generally provided with various 
weights, which are lifted by means of steel cables and pulleys for the 
purpose of building the body of a person using the exercise machine. Such 
a conventional exercise machine as described above is defective in that 
its weights are costly and that it is expensive and inconvenient to 
transport the weights. 
SUMMARY OF THE INVENTION 
It is therefore the primary objective of the present invention to provide 
an exercise machine making use of the body weight of an exerciser as a 
load weight in place of a weight. 
The foregoing objective of the present invention is attained by an exercise 
machine, which comprises a base, a fixation rod, an upper rocking bar, a 
lower rocking bar, an expandable connection rod, a seat pad, a back pad, a 
handle, and a cushioning member. 
The fixation rod is fastened obliquely to the base. The upper rocking bar 
is provided with a plurality of through holes and fastened pivotally to 
the top end of the fixation rod. The lower rocking bar is pivoted to the 
fixation rod such that the lower rocking bar is located under the upper 
rocking bar. The expandable connection rod is pivoted respectively at both 
ends thereof to the upper and the lower rocking bars and is located behind 
the fixation rod. The seat pad is disposed on one end of the lower rocking 
bar. The back pad is pivoted at one end thereof to the lower rocking bar 
and fastened at another end thereof to the fixation rod. The handle is 
fastened to one end of the upper rocking rod. The cushioning member is 
pivoted at one end thereof to the lower rocking bar and fastened at 
another end thereof to the fixation rod.

DETAILED DESCRIPTION OF THE INVENTION 
As shown in FIG. 1, the exercise machine of the present invention is made 
up of the component parts described hereinafter. 
A base 10 is composed of a main tube 11, two cross tubes 12 fastened 
vertically and respectively to both ends of the main tube 11. The base 10 
is placed horizontally on a flat surface. 
A fixation rod member 20 comprises an outer tube 21 fastened obliquely to 
the main tube 11 of the base 10. The fixation rod member 20 has a front 
surface 211 which forms a greater angle with the upper surface of the main 
tube 11. The fixation rod member 20 is provided in one side of the top end 
thereof with a key hole 212, as shown in FIG. 2. The fixation rod member 
20 is further composed of an inner tube 22 received adjustably in the 
axial hole of the outer tube 21, as illustrated in FIG. 3. The inner tube 
22 is provided at the bottom thereof with a sleeve 23 fitted thereover for 
making the inner tube 22 to become more closely associated with the outer 
tube 21. The inner tube 22 is provided with a plurality of through holes 
221. The fixation rod member 20 is still further provided with an L-shaped 
insertion pin 24, which is put through the key hole 212 and one of the 
through holes 221 of the inner tube 22 for fastening and locating the 
inner tube 22 and the outer tube 21. The insertion pin 24 has a protruded 
portion 241 capable of working in conjunction with a slot 213 of the key 
hole 212 to prevent the insertion pin 24 from becoming disengaged. 
An upper rocking bar member 30 is provided with a predetermined number of 
through holes 31 and is pivoted by means of an L pin 32 to two lugs 222 
located at the top of the inner tube. As a result, the upper rocking bar 
member 30 is provided with an adjustable fulcrum. The upper rocking bar 
member 30 has a round tube 33 opposite to the back surface of the outer 
tube 21. The round tube 33 is provided centrally and radially with a long 
slot, which is not shown in the drawing. 
As shown in FIG. 4, a lower rocking rod member 40 comprises two parallel 
tubes 41, one support tube 42 fastened to the two parallel tubes 41, and a 
round tube 43 fastened to the two parallel tubes 41 and provided centrally 
and radially with a long slot 431. The outer tube 21 is provided at a 
predetermined position thereof with an inner sleeve 25. The lower rocking 
bar member 40 is arranged at both sides of the outer tube 21 by means of 
the two parallel tubes 41. Located between the outer tube 21 and the two 
parallel tubes 41 are two oily bearings 44. A threaded rod 45 is put 
through the inner sleeve 25, two bearings 44 and the two parallel tubes 
41, and is then fastened with a nut 46. 
As shown in FIG. 5, an expandable connection rod 50 comprises a nut 51 of 
long tubular construction and having respectively at both ends thereof a 
reverse threaded hole 511, and two threaded rods 52 engaging respectively 
the threaded hole 511 and capable of being caused to move simultaneously 
in opposite directions. These two threaded rods 52 are disposed pivotally 
and respectively at one end thereof in the long slots of the round tubes 
33 and 43 of the upper and the lower rocking bar members 30 and 40. In 
other words, the two threaded rods 52 are pivoted similarly to the upper 
and the lower rocking bar members 30 and 40. Therefore, only the pivoting 
method of the lower rocking bar member 40 is described here. As shown in 
FIGS. 6 and 7, the threaded rod 52 is put through the long slot 431 of the 
round tube 43 and a round rod 53 disposed in the round tube 43. An 
insertion pin 54 is put through the round rod 53 and the threaded rod 52 
which is capable of rocking in the long slot 431. The nut 51 is 
additionally provided with an elastic tube 55 for providing an easy grip 
on the nut 51. 
A seat pad is fastened securely to the support tube 42 of the lower rocking 
bar member 40. 
A back pad 70, as shown in FIGS. 1 and 4, is provided with two support 
tubes 71 under which a round tube 72 is disposed securely. An L pin 73 is 
detachably pivoted between the two parallel tubes 41 of the lower rocking 
bar member 40. A rolling wheel 74 is pivotally mounted on the support tube 
71 so that the back pad 70 is held on to the fixation rod member 20 when 
the lower rocking bar member 40 is caused to rock upwards and downwards. 
A handle 80 is fastened to one end of the upper rocking bar member 30. 
A cushioning member 90 of an oil-pressure cylinder is pivoted at one end 
thereof to the fixation rod member 20 (or the base 10) and at another end 
thereof to the lower rocking bar member 40, or the upper rocking bar 
member 30, or the connection bar member 50, for allowing the lower rocking 
bar member 40 to return to its stationary position at a moderate pace. 
A bracing tube 95 is fastened at one end thereof to the base 10 and at 
another end thereof to the fixation rod member 20. Provided respectively 
at both sides of the bracing tube 95 is an elastic padded tube 96. 
The operation of the exercise machine of the present invention is 
schematically illustrated in FIGS. 8, 9 and 10. 
An exerciser is seated on the seat pad 60, with both hands holding the 
handle 80, which is then pushed upwards. The force exerting upwardly on 
the handle 80 is designated as F. Through the two lever actions of the 
upper rocking bar member 30 and the lower rocking bar member 40, if the 
force F is greater than the force exerting on the seat pad 60 by the body 
weight W of the exerciser and the resultant force (F+W) of a reactive 
force F' of the seat pad 60, the handle 80 can be pushed upwards so as to 
cause the seat pad 60 to rise. It must be noted here that the displacement 
quantity .lambda.1 of the handle 80 must be greater than the displacement 
quantity .lambda.2 of the seat pad 60 so as to permit the exerciser to 
push the handle 80 upwards in a comfortable manner, as illustrated in FIG. 
10. Assuming that the force exerting on the handle is designated as F; the 
body weight of the exerciser, W; the force acting on the seat pad, F' 
(reactive forece)+W; the upper rocking bar, a1:a2; and the lower rocking 
bar, b1:b2; then 
##EQU1## 
let a1b1&gt;a2b2 
##EQU2## 
EXAMPLE 1 
##EQU3## 
EXAMPLE 2 
##EQU4## 
EXAMPLE 3 
EQU a1:a2=2:1 b1:b2=1:1.fwdarw.F.gtoreq.W 
The ratio of b1 and b2 is set in advance at the time when the exercise 
machine is manufactured. The ratio of a1 and a2 can be altered by 
adjusting the pivoting point of the upper rocking bar member 30. 
The fixation rod member 20 is adjustable and can be adjusted in accordance 
with the height of an exerciser. The length of the expandable connection 
rod member 50 can be adjusted by adjusting the pivoting position of the 
upper rocking bar member 30 or the length of the fixation rod member 20. 
An exerciser may use the exercise machine of the present invention by 
seating or standing on the seat pad 60.