BALL POINT PEN WITH TWO AVAILABLE COLORS BACKGROUND OF THE INVENTION Field of the Invention: This invention relates to ball point pen with two leads of different colors, which can be easily selected by user while writing.

Description of the Prior Art: Generally, writing devices are composed of pencil which produces writing by leaving graphite on the paper due to the writing pressure and ball point pen or fountain pen which transcribes ink on the paper by the function of small ball on the tip of pen that revolves while writing due to the friction with paper and extracts ink from cartridge.

Since the above writing devices are monochromatic, users generally underline the important parts with writing devices of another color or fluorescent pen after writing with the above writing devices.

However, the above conventional writing devices take much time to underline or rewrite for differentiating important parts from other letters. What is worse, since they do not ensure uniform shape, the letters are not neat, thereby lowering user's concentration and work efficiency.

In order to solve this problem, as indicated in the figure 1, the present writing devices fix supporting part (20) with two perforating holes (21) inside the upper body (11) whose inside is perforated. Then, black and red leads of ball point pen are combined

from lower part to upper part through these perforating holes (21) to be protruded on the upper part of supporting part (20).

Spring (30) is attached to the upper surface of supporting part (20) by being inserted from upper part to lower part so that it can be positioned on the top of thus protruded black and red leads of ball point pen. Pressing each lead of ball point pen, the pressing part (40) with protrusion (41) is combined to the inside of lead of ball point pen in order to be consistently formed to the upper surface of upper body (11).

Then, setting the lower body (12) to the lower part and upper part of upper body (11) to assemble it by revolution, writing devices are (10) complete.

By the way, the writing devices recently constituted as above have problems, namely, as the pressing part is positioned at the top of writing device, the posture of hand is disheveled, because user switches the color by thumb, which impedes prompt color conversion, resulting in inconvenience.

SUMMARY OF THE INVENTION This invention relates to make case in which two leads of ball point pen of different colors are placed and working part that selects one of the leads by user's index finger. Since the user can easily switch the color while writing without largely changing the posture of his hand, this two colored ball point pen is very convenient to write with.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 indicates general ball point pen, a is slant figure,

b is cross section.

Figure 2 is the separate slant figure of this invention Figure 3 is the front cross section of this invention in the state of assembly Figure 4 is the lateral cross section of this invention in the state of assembly Figure 5 indicates the working state of black ball point pen to which this invention is applied, a is front cross section, b is lateral cross section.

Figure 6 indicates the working state of red ball point pen to which this invention is applied, a is front cross section, b is lateral cross section.

<Explanation on marks for main parts of the drawing > 100: case 110: body 113: settling groove 114: stopping hole 115: slide groove 120: upper cap 130: lower cap 200: working part 210: circular gear 220: the first balancing gear

230: the second balancing gear 240: stopper 250: converting part DETAILED DESCRIPTION Considering the above-mentioned conventional defects, This invention aims to enable user to easily select the two leads of ball point pen of different colors by index finger while writing without largely changing the posture of his hand, thereby providing writing devices with which user can easily write in two different colors.

In order to achieve this purpose, This invention consists of case in which two leads of ball point pen of different colors are placed ; working part with which the user can easily select one of the two leads of ball point pen by index finger.

COMPOSITION AND FUNCTION OF THE INVENTION On the basis of attached drawings, the actual example of using this invention is explained in details. Figure 2 is the separate slant figure of this invention.

This invention relates to case (100) in which two leads of ball point pen of different colors are placed and working part (200) that selects one of the two leads installed in the above case (100) by user's index finger. To be more specific, they are as follows.

The above case (100) has perforated inside and screw stairs (111) (112) at the upper and lower part. Settling groove (113) is formed on the upper surface and 4

perforated stopping holes (114) are formed at the lower part of this settling groove (113) in regular distance. Multi-layer slide groove (115) with broad lower part and narrow upper part is formed at lower part of the Body (110). Upper cap (120) that is combined to the upper screw stairs (lll) of the above body (HO) and has fixing prominence (121) inside is prepared. Lower cap (130) that is combined to the lower screw stairs (112) of the above body (110) and has perforated holes (131) inside is also prepared.

The above working part (200) is settled at the settling groove (113) of the above body (110) and circular gear (210) with circumferential saw tooth (211) is prepared.

Saw tooth (221) that moves upward and downward, being attached to the one side of saw tooth (211) of the above circular gear (210) is formed. At the bottom of this saw tooth (221) is protruded fixed protrusion (222). At the lower surface of the same saw tooth is prepared the first balancing gear (220) that has inserting protrusion (223) to which the upper part of lead of ball point pen is inserted. Saw tooth (231) that moves upward and downward, being attached to the other side of saw tooth (211) of the above circular gear (210) is formed. At the lower surface is prepared the second balancing gear (230) that has inserting protrusion (232) to which the upper part of lead of ball point pen is inserted. Fixed hole (241) that is combined to the fixed protrusion (222) of the first balancing gear (220) is perforated and at the lower part of this fixed hole (241) is prepared stopper (240) to which elastic piece (242) with slantwise protruded combining protrusion (243) is formed in opposite.

Moreover, guiding entrance (251) through which guiding hole (252) is perforated

so that the combining protrusion (243) of the above stopper (240) is slantwise inserted is formed. Connecting rod (253) that slides along the above slide groove (115), being attached to the lower part of the above guiding entrance is formed. Converting part (250) that protrudes in front of the above slide groove (115), being attached to the ending part of this connecting rod (253) and has the control knob (254) to select the above leads of ball point pen is prepared.

Here comes explanation on combining process of This invention which is constituted as above.

To begin with, as indicated in figure 3 and 4, fix the black lead of ball point pen (B) and red lead of ball point pen (R) at the inserting protrusions (223) (232) of the first and second gear (220) (230). Then, fix the fixed hole (241) of stopper (240) at the fixed protrusion (222) of the first balancing gear and make the saw tooth (221) (231) of the first and second balancing gear (220) (230) face each other.

At this state, attach the guiding entrance (251) of converting part (250) to the combining protrusion (243) of stopper (240) in order to position it inside the guiding hole (252) and move it from the lower part to the upper part of case (l 00) body (110).

Then, the stopper (240) in the body (110) moves upward by the elasticity of elastic piece (242), being attached to the inside of body (110).

As above, once stopper (240) moves upward in certain distance and combining protrusion (243) (243a) is fixed at the stopping hole (114b) (114a) of body (110), the guiding hole (252) of guiding entrance (251) presses combining protrusion (243) (243a) to detach it from stopping hole (114b) (114a). Then, the combining

protrusion (243) (243a) of stopper (240) moves downward along the inner surface of body (110), while being inserted in the guiding hole (252), to be positioned at rear of the stopping hole (l 14c) (114b). It is then combined to the stopping hole (114b) (114a) by the elasticity of elastic piece (242).

Then, once the controlling knob (254) of converting part (250) is exposed outside of the body (l 10) through the lower part of slide groove (l 15) and moves upward along the slide groove (115), the combining protrusion (243a) (243) of stopper (240) is detached from the stopping hole (114b) (114c) to be fixed, being stuck by stopping hole (114c) (114d).

As above, once the combining protrusion (243a) (243) of stopper (240) is fixed at the stopping hole (114c) (114d), the first and second balancing gear (210) (220) protrudes to the upper part of body (110). In order to position the circular gear (210) at the center of saw tooth (221) (231) of the first and second balancing gear (210) (220), saw tooth (211) moves toward the lower part of body, being combined. The guiding hole (252) of guiding entrance (251) presses the combining protrusion (243) (243a) and detaches from the stopping hole (114d) (114c) to move downward so that the circular gear (210) can be settled at the settling groove (l 13).

Then, the combining protrusion (243) (243a) of stopper (240) is fixed at the stopping hole (114c) (114b) and the combination of working part is completed.

If the combination of working part (200) is completed as above, the upper cap (120) is fixed at the screw stairs (111) of body (110), being revolved in regular direction, and the fixing prominence (121) of the upper cap is attached to the upper surface of

body (HO) so that circular protrusion (210) can be supported to revolve without being detached from the settling groove (113).

Once the lower cap (130) is revolved in regular direction and fixed to the screw stairs (l 12) of the above body (110), the combination of case (l00) is completed.

Next comes explanation on how to use This invention installed as above.

To use the black lead (B) of ball point pen, as indicated in figure 5, make the controlling knob (254) of converting part (250) move downward along the slide groove (115) using thumb. Then, the guiding hole (252) of guiding entrance (251) presses the combining protrusion (243) (243a) of stopper (240) to detach it from the stopping hole (l 14c) (114b).

Then, being inserted at the guiding hole (252), the combining protrusion (243) (243a) of stopper (240) moves downward along the inner surface of body (l 10) to be positioned at rear of the stopping hole (114b) (114a). It is then combined to the stopping hole (114b) (114a) by the elasticity of elastic piece (242).

If the first balancing gear (220) connected to the above stopper (240) moves downward, the circular gear (210) combined to the saw tooth (221) of the first balancing gear (220) revolves counterclockwise and the joining saw tooth (231) moves upward to move the second balancing gear (230) upward.

Then, the ending part of black lead (B) of ball point pen combined to the inserting protrusion (223) of the first balancing gear (220) protrudes through the perforating hole (131) of the lower cap (130), user can write with the black lead (B) of

ball point pen.

To use the red lead (R) of ball point pen, as indicated in figure 6, make the controlling knob (254) of converting part (250) move upward along the slide groove (115) using index finger. Then, the guiding hole (252) of guiding entrance (251) presses the combining protrusion (243) (243a) of stopper (240) to detach it from the stopping hole (l 14c) (114b).

Then, being inserted at the guiding hole (252), the combining protrusion (243) (243a) of stopper (240) moves upward along the inner surface of body (110) to be positioned at rear of the stopping hole (l 14d) (114c). It is then combined to the stopping hole (114d) (114c) by the elasticity of elastic piece (242).

If the first balancing gear (220) connected to the above stopper (240) moves upward, the circular gear (210) combined to the saw tooth (221) of the first balancing gear (220) revolves clockwise and the joining saw tooth (231) moves downward to move the second balancing gear (230) downward.

Then, the ending part of red lead (R) of ball point pen combined to the inserting protrusion (232) of the second balancing gear (230) protrudes through the perforating hole (131) of the lower cap (130), user can write or underline with the red lead (R) of ball point pen