An in-line roller skate, which includes a boot, a front wheel frame and a rear wheel frame respectively pivoted to the sole of the boot by rivets and arranged in a line to hold a respective pair of longitudinally aligned wheels, a brake block selectively fastened to the front wheel frame or rear wheel frame, and two elastic blocks respectively mounted in between a respective bottom trough at the sole of the boot and a respective top trough at one of the wheel frames to absorb shocks and to compensate sideways component of force upon turning of the in-line roller skate.

BACKGROUND OF THE INVENTION 
The present invention relates to an in-line roller skate, and more 
particularly to such an in-line roller skate which comprises a foot, two 
wheel frames respectively pivoted to the sole of the boot by rivets to 
hold a plurality of wheels in a line, and two elastic blocks coupled 
between the boot and the wheel frames to absorb shocks and buffer tilting 
force. 
In conventional roller skates, wheels are arranged in pair. When skating, 
the wheels are moved along two parallel skating lines (see FIG. 2). 
Because of much contact area between the wheels and the ground, much 
resistance is produced when skating on a conventional roller skate. 
Further, the wheels of a conventional roller skate may be struck with 
stones or foreign objects during skating. Therefore, it is difficult to 
make a smooth skating on a conventional roller skate. Recently, in-line 
roller skates have become more and more popular for the advantages of high 
performance. An in-line roller skate, as shown in FIG. 1, is comprised of 
a plurality of wheels arranged in a line. The wheels for in-line roller 
skate commonly have a smoothly curved periphery (see FIG. 3). This design 
diminishes the contact area between the wheels and the ground. Because the 
wheels of the in-line roller skate are arranged on a wheel frame in a 
line, the in-line roller skate can be moved at a high speed. However, this 
design cannot make the skater take a turn except the skater lifts the toe 
or heel. When lifting the toe or heel, users must pay attention in order 
to keep the body in balance. Furthermore, because the wheel frame of an 
in-line roller skate is a solid frame, a single wheel receives much torque 
when the skater deflects the roller skate. So the wheel of an in-line 
roller skate wears quickly with use. Therefore, this conventional in-line 
roller skate is not durable in use. FIG. 4 shows another structure of 
roller skate according to the prior art. This structure of roller skate 
comprises a sole plate fixedly mounted on the sole of the boot thereof to 
hold a rear wheel and a heel stop (brake block). A bolt is raised from the 
sole plate near its front side to hold a bearing and a wheel spring 
holder. The wheel spring holder has two side lugs. A spherical wheel is 
coupled between the side lugs on the wheel spring holder. This structure 
of roller skate allows the skater to freely switch the skating direction. 
However, it is difficult to keep the roller skate in balance when making a 
turn or snake skating. Therefore, this structure of roller skate is not 
suitable for beginners. 
SUMMARY OF THE INVENTION 
The present invention provides an in-line roller skate which eliminates the 
aforesaid drawbacks. According to one aspect of the present invention, the 
in-line roller skate comprises a boot, a front wheel frame and a rear 
wheel frame mounted on the sole of the boot and arranged in a line to hold 
a respective pair of longitudinally aligned wheels, and two elastic blocks 
mounted in between a respective bottom trough at the sole of the boot and 
a respective top trough at one of the wheel frames to absorb shocks and to 
compensate sideways component of force upon turning of the in-line roller 
skate. According to another aspect of the present invention, the front 
wheel frame and the rear wheel frame are respectively pivoted to the sole 
of the boot thereof by rivets, therefore they can be respectively turned 
leftwards or rightwards about the respective rivet. According to still 
another aspect of the present invention, the front wheel frame has a 
bottom screw hole near its front end, the rear wheel frame has a bottom 
screw hole near its rear end, and a brake block can be selectively 
fastened to the bottom screw hole at the front wheel frame or the rear 
wheel frame as desired.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 5, an in-line roller skate in accordance with the present 
invention is generally comprised of a boot 1, a front wheel frame 2, a 
rear wheel frame 3, two rivets 4, two elastic blocks 5, a brake block 6, 
and four wheels 7. 
The boot 1 is injection-molded from plastics, comprising two studs 10 
raised from the sole thereof near two opposite ends, the studs 10 each 
defining a through hole 100 through the sole, a first bottom trough 12 and 
a second bottom trough 13 transversely disposed at the sole and spaced 
between the studs 10, and a plurality of mounting holes 120 and 130 
respectively provided in the bottom troughs 12 and 13 through the sole. 
The wheel frames 2;3 are respectively fixedly fastened to the sole of the 
boot 1 by the rivets 4, and longitudinally arranged in a line. Each wheel 
frame 2 or 3 comprises a through hole 20 or 30 respectively fastened to 
the through holes 100 in the studs 10 at the boot 1 by the rivets 4, a top 
trough 21 or 31 disposed at the top corresponding to one recess 12 or 13 
at the sole of the boot 1, a plurality of mounting holes 210 or 310 in the 
top trough 21 or 31 corresponding to the mounting holes 120 or 130 in the 
bottom trough 12 or 13 at the sole 1, two transverse axle holes 23 or 33, 
and two bolts 24 or 34 respectively mounted in the transverse axle holes 
23 or 34 to hold one pair of the wheels 7 in a line. One wheel frame 2 has 
a downwardly extended screw hole 22 near its front side. The other wheel 
frame 3 has a downwardly extended screw hole 32 near its rear side. The 
rivets 4 are respectively fastened to the through holes 100 in the studs 
10 at the boot 1 and the through holes 20;30 at the wheel frames 2;3 to 
secure the wheel frames 2;3 to the boot 1, enabling the wheel frames 2;3 
to be turned about the rivets 4 leftwards or rightwards. The elastic 
blocks 5 are molded from rubber, and respectively mounted in between the 
bottom troughs 12 and 13 at the sole of the boot 1 and the top troughs 21 
and 31 at the wheel frames 2 and 3 Each elastic block 5 comprises a side 
open chamber 50, and a plurality of mounting holes 51 through top and 
bottom side walls thereof in communication with the side open chamber 50. 
Further, two reinforcing rigid plates 52 are mounted in the side open 
chamber 50 in each elastic block 5 at top and bottom sides, each having a 
plurality of screw holes 520 respectively fastened to the mounting holes 
51 at the corresponding elastic block 5 by respective fastening elements 
53. The fastening elements 53 can be screws or rivets. The brake block 6 
can be fastened to the screw hole 22 at the front wheel frame 2 or the 
screw hole 32 at the rear wheel frame 3. The wheels 7 are respectively 
mounted in the wheel frames 2;3, and turned about the bolts 24;34. 
The assembly process of the in-line roller skate is outlined hereinafter 
with reference to FIG. from 5 through 7. The elastic blocks 5 are 
respectively mounted in between the bottom troughs 12 and 13 at the sole 
of the boot 1 and the top troughs 21 and 31 at the wheel frames 2 and 3, 
then fastening elements 53 are respectively inserted through the mounting 
holes 120 and 130 at the boot 1 and mounting holes 210 and 310 at the 
wheel frames 2 and 3 from top and bottom sides into the mounting holes 51 
at the elastic blocks 5, and then threaded into the screw holes 520 at the 
rigid plates 52, and then the rivets 4 are respectively mounted in the 
through holes 100 at the boot 1 and the through holes 20 and 30 at the 
wheel frames 2 and 3 to secure the boot 1 and the wheel frames 2 and 3 
together, and then the wheels 7 are respectively fastened to the front 
wheel frame 2 and the rear wheel frame 3 by the bolts 24;34, and then the 
brake block 6 is fastened to the screw hole 22 at the front wheel frame 2 
or the screw hole 32 at the rear wheel frame 3. 
Referring to FIGS. from 8 through 12 and FIG. 7 again, when the user skates 
straightway forwards, the four wheels 7 are longitudinally aligned, and 
the elastic blocks 5 are compressed at an amount "A" (see FIG. 10) to 
absorb shocks. When making a turn or changing the skating direction, the 
roller skate is slightly tilted leftwards or rightwards subject to the 
desired direction, thereby causing the wheels 7 to deviate from the 
longitudinal central line C at an angle .theta. (see FIG. 7), and 
therefore the wheels 7 are moved forwards along a curve line. When the 
wheels 7 are forced to deviate from the longitudinal central line C at a 
distance B (see FIG. 9), the elastic blocks 5 buffer the tilting force, 
therefore the skater can smoothly maintain the body in balance (such as 
riding a bicycle in hand free, but won't get fall). When the skater 
performs a fancy skating, the front wheel frame 2 and the rear wheel frame 
3 are suffering a downward pulling force. And then the elastic blocks 5 
and the rivets 4 can bear the downward pulling force and fix the front 
wheel frame 2 and the rear wheel frame 3 accordingly. When the tilting 
force is released, the elastic blocks 5 immediately return to their former 
shape (see FIG. 8), and the wheels 7 are returned to the longitudinally 
aligned position. If the skater is going to fall when skating, the wheels 
7 are a utomatically forced to deviate from the longitudinal central line 
C at an angle, so as to support the skater in a balanced manner. When the 
skater performs a fancy skating, the elastic blocks 5 are compressed or 
twisted to bear the force from the foot, so that the skater can be 
maintained in balance. When the skater jumps, the elastic blocks 5 are 
vertically compressed to absorb the pressure (see FIG. 12), enabling the 
skater to keep the body in balance. 
Further, because the wheels 7 are respectively mounted on the front wheel 
frame 2 and the rear wheel frame 3, the front wheel frame 2 and the rear 
wheel frame 3 are forced to deflect separately when the roller skate is 
tilted in one direction. Therefore, the front wheel frame 2 and the rear 
wheel frame 3 receive no torque when the skater changes the skating 
direction. This design greatly prolongs the service life of the in-line 
roller skate.