Quick adjusting device for bicycle brake cable

The present invention relates to a quick adjusting device for bicycle cables, and especially to a device having a substantially S-shaped base which cooperates with a cam, a worm and a worm gear to adjust a bicycle brake cable. Two plates formed on the bottom of the base to define an area. A wheel is slidably mounted on the cam. The worm gear and the wheel, together, clamp the brake cable. The brake cable is driven and adjusted by the worm gear and the wheel by inserting a hexagon wrench into a hexagonal slotted head of the worm and turning. A pulley is rotatably received in an area of the base for adjusting the relative position of the left side and the right side brake arms.

BACKGROUND OF THE INVENTION 
The present invention relates to a quick adjusting device for bicycle brake 
cables, and especially to a device having a substantially S-shaped base, a 
camshaft, a worm, a worm gear shaft, and a pulley. Two plates are formed 
on the bottom of the base and define an area. The worm gear and the wheel, 
together, clamp a brake cable. The wheel is located on the camshaft. The 
brake cable is driven by the worm to move upwards or downwards via the 
worm gear and the wheel. A pulley is received in an area of the base and 
used to adjust the relative position of the left side and the right side 
brake arms. 
Conventional bicycles use cross-type brake arm in their brake devices. In 
another type of bicycle brake device, the brake arms is installed 
independently on a right side and a left side of the front and rear forks 
of the bicycles. The brake cables of these bicycle brake devices are easy 
to loosen but not easy to adjust after it has been used for a period of 
time. Furthermore, if two brake arms of the bicycle are not in the right 
position, it is very difficult to adjust. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide a quick adjusting 
device for bicycle cables. 
Another object of the present invention is to provide a device having a 
base which cooperates with a worm, a worm gear, and a wheel to adjust the 
brake cable to an optimum length. 
It is still another object of the present invention to provide a pulley to 
adjust the brake arms easily. 
Other objects and advantages will be apparent to those skilled in the art 
upon reading the detailed description provided hereinbelow with 
appropriate reference to the accompanied drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIG. 1 and 2, a quick adjusting device for bicycle cables 
of the present invention comprises a base 1, a camshaft 2, a worm gear 
shaft 3, a worm 4 and a pulley 5. 
The base 1 is substantially S-shaped and has a top wall 11, a front wall 
12, a rear wall 13, a right wall 14 and two plates 15. The two plates 15 
are forked from a bottom portion of the rear wall 13 and define an area 
16. The top wall 11 has an aperture 111 to let the brake cable 6 pass 
through. The right wall 14 has an opening 142 for installing the worm 4. 
The right wall 14 and a small plate 112, having a hole, together form a 
worm bracket 141. The small plate 112 protrudes from an inner side of the 
top wall 11. The front wall 12 has a cam-hole 121 which includes a first 
slot 122 and a worm-gear-hole 123. The worm-gear-hole 123 also has a 
second slot 124 thereon. The cam-hole 121 and the wormgear-hole 123 are in 
the same plane. The first slot 122 and second slot 124 extend outward in 
approximate opposite directions to each other. The rear wall 13 has a 
first hole (not shown) and a second hole 126, respectively in line with 
the cam-hole 121 and the worm-gear-hole 123 in the front wall 12. A pair 
of pulley holes 151 are formed symmetrically on the two plates 15. A 
fixing hole 131 is formed at a lower part of the rear wall 13. 
The camshaft 2 has a cam 21 formed thereon and a wheel 22 rotatably mounted 
on the cam 21. An annular slot 23 is formed on the wheel 22. A first 
journal 24 is formed adjacent to the cam 21. The camshaft 2 is mounted to 
the cam-hole 121 and the first hole via the first journal 24 through the 
first slot 122 and riveted to to base 1. 
The worm gear shaft 3 has a worm gear 31 which is slidably and rotatably 
mounted thereon, and a second journal 32 formed adjacent to the worm gear 
31. The worm gear shaft 3 is mounted to the worm-gear-hole 123 and the 
second hole 126 via the second journal 32 through the second slot 124 and 
riveted to the base 1. 
The worm 4 is mounted on the worm bracket 141 and attached above and in 
contact with the worm gear 31. The worm 4 has a hexagon slotted head 41. 
The worm gear 31 is driven by the worm 4 by means of inserting a hexagonal 
wrench into the hexagonal slotted head 41 and turning. 
The pulley 5 is rotatably mounted on a pulley shaft 51 within the area 16 
between the two plates 15. The pulley shaft 51 is put into the pair of 
pulley holes 151 and riveted to the base 1. 
The wheel 22 is preferably made of elastic material. The brake cable 6 
first passes through the aperture 111 of the top wall 11 and then passes 
through the space between the annular slot 23 and the worm gear 31. The 
annular slot 23 and the worm gear 31, together, clamp the brake cable 6 
tightly. Since the wheel 22 is elastic, the brake cable 6 is pushed to 
contact the worm gear 31. When the brake cable 6 is too loose and needs 
tightening, a hexagon wrench is inserted into the hexagonal slotted head 
41 of the worm gear 4 to drive the worm gear 31 and adjust the brake cable 
6. When the worm gear 31 is driven counterclockwise, the teeth of the worm 
gear 31 and the wheel 22 together force the cable 6 to move downward. 
Since the wheel 22 is slidably and rotatably mounted on the cam 21, the 
wheel 22 slides relative to the cam 21 while the cam 21 does not move to 
assure the wheel 22 contacts to the worm gear 31. A screw 7, two washers 
72 and a nut 73 are used to fix the end of the brake cable 6 in a cable 
hole 71 of the screw 7. The whole adjusting or installing procedure is 
completed after the brake cable 6 is released. 
Furthermore, the brake arm cable 82 first encircles the pulley 5, and then 
attaches to two brake arms 8. The two brake arms 8 extend outward due to 
two springs (not shown in the Figures) on the two brake arms 8. The brake 
arm cable 82 also is in tension and provides sufficient friction between 
the pulley 5 and the brake cable 82. When the pulley 5 turns, the brake 
arm cable 82 also moves due to the frictional force. When the two brake 
arms 8 are not in a proper position, the two brakes 81 of the two brake 
arms 8 can not touch the bicycle wheel simultaneously. Adjustment is made 
simply by turning the pulley 5 to move the brake arm cable 82 and make the 
two brake arms 8 adjust to the correct proper position. 
As various possible embodiments might be made of the above invention 
without departing from the scope of the invention, it is to be understood 
that all matter herein described or shown in the accompanying drawings is 
to be interpreted as illustrative and not in a limiting sense. Thus it 
will be appreciated that the drawings are exemplary of a preferred 
embodiment of the invention.