Balancing structure of brake cables hoisting seat of bicycle

A cable-hoisting apparatus of a bicycle brake comprises a cable-hoisting seat having an axial hole dimensioned to receive therein a bushing which is provided longitudinally with an eccentric through hole serving to enable the cable-hoisting seat to act evenly on the two brake cables so as to cause both brake shoes to arrest simultaneously the rim of a bicycle wheel in motion.

BACKGROUND OF THE INVENTION 
The present invention relates generally to the braking system of a bicycle, 
and more particularly to the balancing structure of brake cables hoisting 
seat of a bicycle. 
As shown in FIGS. 3 and 4, the braking system of a conventional bicycle 
comprises a V-shaped cable-hoisting seat 1 and two linked brake seats 2 
and 2'. Located in one wing of the cable-hoisting seat 1 is a fixed end 12 
provided with a cable hole 121 in which a steel brake cable 13 is received 
securely. The brake cable 13 is fastened at one end thereof with the brake 
seat 2'. Located in another wing of the cable-hoisting seat 1 is an urging 
end 15 provided therein concentrically with an upper hole 151 and a lower 
hole 152, which have different diameters. The upper hole 151 is 
dimensioned to hold a sheathed fitting head 171 of another steel brake 
cable 16 which is received securely in the lower hole 152 and is fastened 
at one end thereof with another brake seat 2. As shown in FIG. 3, the 
steel brake cable 16 has a sheathed end 17 which is fastened at one end 
thereof with a brake lever. As the brake lever is triggered with hand, the 
brake seat 2 is caused to turn toward the rim 3 of the wheel 32 of the 
bicycle. In the meantime, the urging end 15 of the cable-hoisting seat 1 
is caused to move downwards, thereby bringing about an upward movement of 
the fixed end 12 of the cable-hoisting seat 1. As a result, the brake seat 
2' is caused to move toward the rim 3 of the wheel 32 of the bicycle. As 
the brake shoes 21 and 21' of the brake seats 2 and 2' are forced against 
both side edges 31 of the rim 3 of the wheel 32, the bicycle is brought to 
a halt. 
The conventional bicycle braking system described above is defective in 
design in that the effect of the braking system is often undermined by the 
fact that both brake shoes 21 and 21' of the brake seats 2 and 2' often 
fail to make contact simultaneously with the rim 3 of the wheel 32. In 
addition, the cable-hoisting seat 1 and the brake seats 2 and 2' are 
fastened respectively to an upper support tube 42 and a lower support tube 
41, which are welded to the fork tube 4. If the job of welding the lower 
support tube 41 and the upper support tube 42 is done poorly, the 
operation of the cable-hoisting seat 1 and the brake seats 2 and 2' can be 
further undermined. 
SUMMARY OF THE INVENTION 
It is therefore the primary objective of the present invention to provide a 
cable-hoisting seat of a bicycle braking system with an eccentric bushing 
fitted into the axial hole of the cable-hoisting seat for enabling the 
cable-hoisting seat to pull both brake cables in a balancing manner, so as 
to cause both brake shoes to arrest simultaneously the rim of the wheel of 
a bicycle. 
The foregoing objective of the present invention is attained by a 
cable-hoisting means which comprises an axial hole dimensioned to receive 
therein a bushing provided longitudinally with an eccentric through hole 
for enabling both brake shoes mounted respectively on two brake seats to 
arrest the rim of a bicycle wheel simultaneously.

DETAILED DESCRIPTION OF THE INVENTION 
Referring to FIGS. 1, 2 and 3, the present invention is shown to comprise 
the component parts which are described explicitly hereinafter. 
A fork tube 4 is provided with two symmetrically disposed lower support 
rods 41, and with an upper support rod 42 having longitudinally a threaded 
hole 421. 
A cable-hoisting seat 1 of a U-shaped construction is provided with an 
axial hole 11, a fixed end 12, and an urging end 15. The fixed end 12 is 
provided with a cable hole 121 for receiving therein a steel brake cable 
13 which is fastened at one end thereof with a brake seat 2'. The urging 
end 15 is provided concentrically with an upper hole 151 and a lower hole 
152. The upper hole 151 is dimensioned to hold therein a sheathed fitting 
head 171 of another brake cable 16 passing through the lower hole 152 to 
become fastened at one end thereof with another brake seat 2. 
A bushing 6 has a head 61 and a body 63. The head 61 is provided with a 
flange 611 rotatable with finger. The body 63 is provided axially with an 
eccentric through hole 62. The bushing 6 may be provided with a head 612 
of a hexagonal construction, as shown in FIG. 2A. 
In combination, the bushing 6 is fitted into the axial hole 11 of the 
cable-hoisting seat 1 which is then fastened to the upper support rod 42 
by a fastening shaft 7 engageable with the eccentric through hole 62 of 
the bushing 6 and the threaded hole 421 of the upper support rod 42 in 
conjunction with a nut 5 and a washer 51. 
In the process of adjusting the brake system, the fastening shaft 7 is 
first loosened to allow the bushing 5 to be rotated with finger until such 
time when an appropriate fulcrum position of the cable-hoisting seat 1 is 
so attained as to enable both brake cables 13 and 16 to be evenly acted on 
by the cable-hoisting seat 1. As a result, the working of the bicycle 
braking system is so improved that both brake shoes mounted repectively on 
the two brake seats 2 and 2' can be caused to arrest simultaneously the 
rim of the wheel of the bicycle. 
It must be noted here that the body 63 of the bushing 6 has a length that 
is slightly greater than the thickness of the cable-hoisting seat 1 so as 
to enable the cable-hoisting seat 1 to be moved axially along the body 63 
of the bushing 6 at the time when the cable-hoisting seat 1 is acting on 
the brake cables 13 and 16. The use of the nut 5 and the washer 51 between 
the threaded hole 421 of the upper support rod 42 and the cable-hoisting 
seat 1 is to facilitate the process of adjusting the position of the 
bushing 6 on the fastening shaft 7. 
The embodiments of the present invention described above are to be regarded 
in all respects as merely illustrative and not restrictive. Accordingly, 
the present invention may be embodied in other specific forms without 
deviating from the spirit thereof. The present invention is therefore to 
be limited only by the scope of the following appended claims.