Patent Publication Number: US-9844972-B2

Title: Writing and underline-drawing implement

Description:
BACKGROUND 
     Field of the Present Disclosure 
     The present disclosure relates to a writing and underline-drawing implement, and, more particularly, to a writing and underline-drawing implement to allow an underline to be drawn in a straight line with improved straightness. 
     Discussion of the Related Art 
     Conventionally, in order to draw an underline in a straight line, a separate elongate straight object, such as, a ruler may be used. 
     The convention approach brings the separate elongate straight object onto the note or paper and remove the object after completion of the drawing the line. Thus, this may prevent in-depth studies. Without the separate elongate straight object, this disallows an underline to be drawn in a straight line with improved straightness. 
     PRIOR ART DOCUMENTS 
     Patent Documents 
     
         
         Patent document 1: Korean utility model registration number 20-0460052 (Apr. 20, 2012) 
         Patent document 2: Korean utility model application publication number 20-2013-0000228 (Jan. 9, 2013) 
         Patent document 3: Korean patent number 10-0734903 (Jun. 27, 2007) 
       
    
     SUMMARY 
     From considerations of the above situations, the present disclosure provides a writing and underline-drawing implement to allow the user to quickly draw an underline in a straight line with improved straightness without the separate elongate straight object. 
     In an aspect of the present disclosure, there is provided a writing and underline-drawing implement comprising an upper elongate hollow body having an open top portion and a closed bottom portion; a lower elongate hollow body coupled to the upper hollow body, the lower elongate hollow body having a first tip hole; a primary elongate core received in the lower hollow body, the primary elongate core having a first tip portion; a secondary elongate core received in the upper elongate hollow body, the secondary elongate core having the second tip portion, wherein the secondary elongate core has a bottom portion contacting the bottom portion of the upper body; a cap having a second tip hole partially formed in a top portion thereof, the cap being hollow and having an open bottom portion to partially receive and/or passed through by the secondary elongate core, the cap being inserted into the top portion of the upper elongate hollow body, the cap being configured to at least partially move along a length of the upper elongate hollow body; and rotatable guide wheels coupled to the cap at an upper portion of the cap, the cap being disposed between the guide wheels, wherein the secondary elongate core is configured such that the second tip portion passes through and beyond the second tip hole out of the cap when the cap is further inserted in the upper elongate hollow body by a predetermined distance, thereby to reach an underline-drawing mode where when the guide wheels contact and run on a paper, the second tip portion draws a straight line on the paper. 
     In an aspect of the present disclosure, there is provided a writing and underline-drawing implement comprising an elongate hollow body having an open top portion and a closed bottom portion; an elongate core received in the elongate hollow body, the elongate core having the tip portion; wherein the elongate core has a bottom portion spaced from the bottom portion of the body; a cap having a tip hole partially formed in a top portion thereof, the cap being hollow and having an open bottom portion to partially receive and/or passed through by the elongate core, the cap being inserted into the top portion of the elongate hollow body, the cap being configured to at least partially move along a length of the elongate hollow body; and rotatable guide wheels coupled to the cap at an upper portion of the cap, the cap being disposed between the guide wheels, wherein the elongate core is configured such that the tip portion passes through and beyond the tip hole out of the cap when the cap is further inserted in the elongate hollow body by a predetermined distance, thereby to reach an underline-drawing mode where when the guide wheels contact and run on a paper, the tip portion draws a straight line on the paper. 
     In accordance with the above writing and underline-drawing implement, following effects may be realized. Both the writing and underline-drawing modes may be realized in a single pen. This may improve in-depth studies due to the fact that it may dispense the separate elongate straight object. Further, the present writing and underline-drawing implement may allow the user to quickly draw an underline in a straight line with improved straightness without the separate elongate straight object. 
    
    
     
       BRIEF DESCRIPTIONS OF THE DRAWINGS 
         FIG. 1  and  FIG. 2  show respectively perspective views of writing and underline-drawing implements respectively in accordance with a first embodiment and fourth embodiment of the present disclosure. 
         FIG. 3  shows a perspective view of an elongate-core controller of a writing and underline-drawing implement in accordance with a first embodiment and fourth embodiment of the present disclosure. 
         FIG. 4  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with a first embodiment of the present discourse. 
         FIG. 5  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with a second embodiment of the present discourse. 
         FIG. 6  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with a third embodiment of the present discourse. 
         FIG. 7  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with a fourth embodiment of the present discourse. 
         FIG. 8  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with a fifth embodiment of the present discourse. 
         FIG. 9  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with a sixth embodiment of the present discourse. 
         FIG. 10  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with a seventh embodiment of the present discourse. 
         FIG. 11  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with an eighth embodiment of the present discourse. 
         FIG. 12  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with a ninth embodiment of the present discourse. 
         FIG. 13  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with a tenth embodiment of the present discourse. 
         FIG. 14  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with an eleventh embodiment of the present discourse. 
     
    
    
     
       
         
           
               
             
               
                   
               
               
                 Reference numerals 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 100:  
                 upper hollow body 
                 120:  
                 elongate stopper hole 
               
               
                 120a: 
                 upper elongate stopper  
                 120b: 
                 lower elongate stopper 
               
               
                   
                 hole 
                   
                 hole 
               
               
                 130: 
                 isolator 
                 140: 
                 spring support 
               
               
                 150: 
                 body protrusion 
                 160: 
                 position limiter protrusion 
               
               
                 200: 
                 lower hollow body 
                 300: 
                 primary elongate core 
               
               
                 400: 
                 secondary elongate core 
                 420: 
                 the second tip portion 
               
               
                 430: 
                 second stopper protrusion 
                 500: 
                 cap 
               
               
                 520: 
                 cap protrusion 
                 600: 
                 guide wheels 
               
               
                 610: 
                 wheel shafts 
                 700: 
                 spring 
               
               
                 700a: 
                 upper spring 
                 700b: 
                 lower spring 
               
               
                 710: 
                 supporter 
                 720: 
                 coupling protrusion 
               
               
                 800: 
                 stopper 
               
               
                   
               
            
           
         
       
     
     DETAILED DESCRIPTIONS 
     Hereinafter, embodiments of the present disclosure will be described in details with reference to attached drawings. 
       FIG. 1  and  FIG. 2  show respectively perspective views of writing and underline-drawing implements respectively in accordance with a first embodiment and fourth embodiment of the present disclosure.  FIG. 3  shows a perspective view of an elongate-core controller of a writing and underline-drawing implement in accordance with a first embodiment and fourth embodiment of the present disclosure. 
     Referring to  FIG. 1  to  FIG. 3 , a present writing and underline-drawing implement may include an upper hollow body  100 , a lower hollow body  200 , a primary elongate core  300 , a secondary elongate core  400 , a cap  500 , guide wheels  600 , wheel shafts  610 , a spring  700 , a stopper  800  and an elongate-core controller  900 . As used herein, the term “core” may refer to a material to be used for writing or drawing the line, for example, an ink or graphite, etc. 
     The upper hollow body  100  and lower hollow body  200  may be coupled to each other at opposing ends thereof to form a single elongate linear body. 
     The upper hollow body  100  and lower hollow body  200  may have upper and lower inner spaces defined therein, which may be isolated from each other via an isolator  130 . 
     The lower hollow body  200  may have lower and upper portions detachably coupled to each other using a screw coupling. The lower portion of the lower hollow body  200  may taper toward the bottom thereof and may have a first tip hole formed in the bottom to allow entrance and exit of the primary elongate core  300 . 
     In the lower hollow body  200 , a primary elongate core  300  such as a ball-pen ink source core may be disposed. Within the lower hollow body  200  and between a protrusion from a bottom of the primary elongate core  300  and the bottom of the lower hollow body  200 , an elastic member may be disposed. The elongate-core controller  900  abutting to a top of the primary elongate core  300  may be disposed in an upper portion of the lower hollow body  200 . 
     In one upper side face of the lower hollow body  200 , two holes may be vertically-spacedly disposed. The elongate-core controller  900  may have two protrusions horizontally protruding therefrom which may be vertically-spacedly disposed. The two protrusions of the elongate-core controller  900  may vertically move and also move inwardly and outwardly in and from the body in an elastic manner. Thus, when the lower protrusion of the elongate-core controller  900  is engaged with the lower hole of the lower hollow body  200  and the upper protrusion of the elongate-core controller  900  is engaged with the upper hole of the lower hollow body  200 , the elongate-core controller  900  may be in a raised state such that the inner elastic member may push upwards the primary elongate core  300  which may be entirely concealed in the lower hollow body  200 . 
     Otherwise, the upper protrusion of the elongate-core controller  900  is pushed down to be disengaged with the upper hole of the lower hollow body  200 , and then, the upper protrusion of the elongate-core controller  900  may be engaged with the lower hole of the lower hollow body  200 . That is, both the upper and lower protrusions of the elongate-core controller  900  may be engaged with the lower hole of the lower hollow body  200 . Thus, the primary elongate core  300  may be lowered down such that the bottom or tip portion of the primary elongate core  300  may extend out of the lower hollow body  200 , thereby to achieve a writing mode. 
     The above configuration related to the primary elongate core  300 , lower hollow body  200  and primary elongate core  300  may be conventional. Thus, more details about the same may be omitted herein. 
     Further, a configuration of the lower hollow body  200  and primary elongate core  300  may be not limited to the above configuration, for example, including the controller  900 . For example, the configuration of the lower hollow body  200  and primary elongate core  300  may have any configuration applied to a conventional ball pen, sign-pen, sharp-pencil, pencil, etc. as well-known to the skilled person to the art. 
     A configuration including the upper hollow body  100 , secondary elongate core  400 , cap  500 , guide wheels  600  etc. may act as an underline-drawing implement. In use, in a writing mode, while the upper hollow body  100  faces upwards, the primary elongate core  300  may be used to write the content. In an underline-drawing mode, while the upper hollow body  100  faces the paper and the lower hollow body  200  faces upward, the secondary elongate core  400  may be used. 
     On one side face of the upper hollow body  100 , the elongate stopper hole  120  may extend vertically. A first stopper protrusion  810  of the stopper  800  may pass through the elongate stopper hole  120  and may vertically move along and in the vertically elongate stopper hole  120 . 
     The upper hollow body  100  may have an open top portion and may receive therein the secondary elongate core  400 . As used herein, the inner space of the upper hollow body  110  receiving the secondary elongate core  400  may be referred to as a “secondary elongate core space”. A cap  500  may have a core tip hole (or second tip hole) at a top thereof at a center and may have an open bottom portion. Into the open top portion of the upper hollow body  100 , the cap may partially move vertically. As used herein, the inner space of the cap  550  may be referred to as a “cap inner space”. 
     The secondary elongate core  400  in accordance with a first embodiment, second embodiment and third embodiment may be embodied as a conventional ball pen core or pencil core. The secondary elongate core  400  may be disposed in the secondary elongate core space and cap inner space. By a distance by which the cap  500  is inserted into the secondary elongate core space, a tip portion of the secondary elongate core  400  may pass through and beyond the second tip hole out of the cap  500 . The secondary elongate core  400  itself may be fixed in a position. Rather, the cap  500  may vertically move down to allow a tip portion of the secondary elongate core  400  to pass through and beyond the second tip hole out of the cap or vertically move up to allow a tip portion of the secondary elongate core  400  to pass through and beyond the second tip hole into the cap  500 . 
     Distant from the tip portion of the secondary elongate core  400  at a given distance, a second stopper protrusion  430  may be formed on the secondary elongate core  400 . A coil spring  700  may be passed through by the secondary elongate core  400 . The coil spring  700  may have a bottom thereof contacting the second stopper protrusion  430  and may have a top contacting the top of the cap  500 . When the cap  500  is pushed down, the coil spring  700  may be compressed. 
     The stopper  800  may extend downwardly to be coupled to a bottom end of the cap  500 . The stopper  800  may move vertically in a spring-loaded manner. The stopper  800  may have a first stopper protrusion  810  projecting from a bottom end thereof. In one example, as shown in  FIG. 4 , the first stopper protrusion  810  may have a top portion with a right-angled inner step and a downward-tapered outer step. The first stopper protrusion  810  may be inwardly or outwardly move in an elastic manner. 
     When the cap  500  move upwards and thus the right-angled inner step of the first stopper protrusion  810  contacts a top edge of the elongate stopper hole  120 , the cap  500  may stop there. Thus, normally, the cap  500  may not be removed from the upper body  100 . Otherwise, the first stopper protrusion  810  is moved inwardly using a sharp object into the upper hollow body  100 , and, at this state, the cap  500  may be pulled upwards to remove the cap  500  from the upper body. In this way, the secondary elongate core  400  may be replaced. 
     To both opposing side faces of an upper portion of the cap  500 , two wheel shafts  610  may be coupled respectively. In this connection, the two wheel shafts  610  may extend in the same straight line or not. To ends of the wheel shafts  610 , two guide wheels  600  may be coupled respectively to be rotatable. 
     Sizes of the guide wheels  600  may be configured such that while the guide wheels  600  contact the paper face, the cap  500  may be further inserted into the upper body by a certain distance, thereby to allow the tip portion of the secondary elongate core  400  to contact the paper face. 
     A material of the guide wheels  600  may be selected such that the guide wheels  600  may not slip along the paper to disallow drawing of a straight line. In this connection, factors to allow the guide wheels  600  to run in a straight line may include, for example, the wheel material being made of a rubber material with a high friction level; the wheel having an outer portion with small grooves formed along the outer portion to increase a friction force against the paper; an operation of running the wheel while pushing down the cap to increase a friction force against the paper; a suppression of the lateral movement of the wheel; a centering of the tip portion of the secondary core while contacting the paper, etc. 
     The present underline-drawing implement in accordance with the first embodiment, second embodiment and third embodiment will be described in details below in terms of an operation thereof. 
       FIG. 4  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the first embodiment of the present discourse. As shown in  FIG. 4 , in the first embodiment, in a writing mode, a writing module (not shown) including the lower hollow body  200  and primary elongate core  300  may be used to write the content. Then, in an underline-drawing mode, the upper hollow body  100  may turn upside down and the cap or guide wheels  600  may be pushed up to enable the tip portion of the secondary elongate core  400  to protrude out of the cap though the second tip hole and to contact the paper face. Then, the user may move the wheels horizontally with gripping the upper hollow body  100  and thus the two guide wheels  600  may run along with the tip portion of the secondary elongate core  400  in a straight line, thereby to draw an underline in a straight line. 
     After drawing the underline, the user may not push the guide wheels  600 , and thus using the restoration force of the spring  700 , the cap  500  may return to its original position. Thus, the tip portion of the secondary elongate core  400  may be inserted back in the inner space in the cap  500 . 
       FIG. 5  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the second embodiment of the present discourse. As shown in  FIG. 5 , the second embodiment may be different from the first embodiment in that two parallel-adjacent secondary elongate cores  400  to render different colors from each other may be disposed, and the secondary elongate core  400  may not have the second stopper protrusion  430  formed thereon but rather the spring  700  may be disposed between the bottom of the cap  500  and the isolator  130  between the upper and lower bodies. 
     In the second embodiment, the two tip portions of the two secondary elongate cores  400  respectively may protrude out of the cap concurrently. However, when the upper hollow body  100  is tilted, only one of the two tip portions of the two secondary elongate cores  400  respectively may be used to draw one line. 
       FIG. 6  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the third embodiment of the present discourse. As shown in  FIG. 6 , the third embodiment may be different from the first embodiment and second embodiment in that two elongate stopper holes are formed to be spaced vertically from each other in the side portion of the body  100 , that is, the upper elongate stopper hole  120   a  and lower elongate stopper hole  120   b  are formed, and, correspondingly, the first stopper protrusion  810  includes an upper first stopper protrusion  810   a  and lower first stopper protrusion  810   b.    
     In this connection, the upper first stopper protrusion  810   a  is engaged into the upper elongate stopper hole  120   a  and the lower first stopper protrusion  810   b  is engaged into the lower elongate stopper hole  120   b . In this way, the cap  500  may move upwards and the secondary elongate core  400  may be entirely received in the cap  500  and upper hollow body  100 . Otherwise, when both the upper first stopper protrusion  810   a  and lower first stopper protrusion  810   b  are engaged into the lower elongate stopper hole  120   b , the cap  500  may move down and the tip portion of the secondary elongate core  400  may protrude out of the cap  500 . This configuration may be similar to the entrance or exit of the tip portion in the first core as described above. 
     In accordance with the first embodiment, second embodiment and third embodiment, during drawing an underline, the user needs not pushing the guide wheels  600  down against the paper face. 
     In accordance with fourth to eleventh embodiments of the present disclosure as will be described in details below, in a wiring mode, the secondary elongate core  400  may be concealed in the secondary elongate core space and cap inner space, and in an underline-drawing mode, the user may push the guide wheels  600  down against the paper face and thus the cap  500  may be further pushed into the secondary elongate core space to enable the second tip portion  420  to protrude via the second tip hole out of the cap  500 . 
       FIG. 7  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the fourth embodiment of the present discourse. As shown in FIG.  7 , in the fourth embodiment, distant upwardly from the isolator  130  between the upper hollow body  100  and lower hollow body  200  at a given distance, a spring support  140  may be disposed in the upper hollow body  100 . The spring support  140  may have a core hole which may be passed through by the secondary elongate core  400 . The spring support  140  may have an outer edge coupled to the upper hollow body  100  at an inner periphery of the body  100 . Thus, the spring support  140  may have a ring shape. 
     Further, in the fourth embodiment, to a side face of a portion of the secondary elongate core  400  distant downwardly from the second tip portion at a given distance, the second stopper protrusion  430  may be disposed. A coil upper spring  700   a  may be passed through by the secondary elongate core  400  and may extend between the second stopper protrusion  430  and the cap  500 . The coil upper spring  700   a  may be compressed when the cap  500  is further inserted into the upper body  100 . Further, a coil lower spring  700   b  may be passed through by the secondary elongate core  400  and may extend between the second stopper protrusion  430  and the isolator  130 . The coil lower spring  700   b  may be compressed when the cap  500  is further inserted into the upper body  100 . In this connection, the second stopper protrusion  430  and lower spring  700   b  may act to prevent the secondary elongate core  400  from moving much toward the isolator  130 . The second stopper protrusion  430  and upper spring  700   a  may act to prevent the secondary elongate core  400  from moving out of the cap  500 . 
     The secondary elongate core  400  may be configured that the bottom thereof should not contact the isolator  130  even via maximum insertion of the cap  550  into the upper body  100 . Otherwise, when the secondary elongate core  400  contacts the isolator  130 , a contacting force of the guide wheels  600  against the paper may be reduced to form a poor straight line because the secondary elongate core  400  is fixed in a position and only the cap  500  move in an elastic manner. 
       FIG. 8  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the fifth embodiment of the present discourse. As shown in  FIG. 8 , in the fifth embodiment, an upper spring  700   a  may be disposed between a top of the cap  500  and second stopper protrusion  430 , wherein the second stopper protrusion  430  may be disposed at a given distance downwardly from the second tip portion of the secondary elongate core  400 . Further, a supporter  710  may be supported by a lower spring  700   b . The supporter  710  may have a coupling protrusion  720  extending upwardly from the supporter  710  to be fitted to a bottom groove of the secondary elongate core  400 . The lower spring  700   b  may be disposed between the bottom of the supporter  710  and the isolator  130  between the upper and lower hollow body  100  and  200 . 
     In the fifth embodiment, the secondary elongate core  400  may not contact the isolator  130  due to the lower spring  700   b  therebetween. Since the bottom hole of the secondary elongate core  400  is fitted with the coupling protrusion  720 , the secondary elongate core  400  may be prevented from entirely moving out of the cap  500 . 
     When the secondary elongate core  400  include two secondary elongate cores as shown in  FIG. 5 , the coupling protrusion  720  may include two coupling protrusions arranged side by side. 
     In the above-described fourth embodiment and fifth embodiment, while the secondary elongate core  400  is supported by the spring not to contact the isolator  130 , the secondary elongate core  400  may be prevented from entirely moving out of the cap  500 . In sixth to tenth embodiments as will be described later, the cap  500  may not be removed from the upper body  100  while the cap  500  may move vertically or may be fixed. Each of the fourth embodiment and fifth embodiment (two embodiments) may be applied to all of the sixth to tenth embodiments (five embodiments). Thus, combinations between the former two embodiments and the latter five embodiment may lead to ten embodiments. 
       FIG. 9  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the sixth embodiment of the present discourse. As shown in  FIG. 9 , in the sixth embodiment, on a side face of the upper hollow body  100 , an elongate stopper hole  120  may be defined vertically. The first stopper protrusion  810  of the stopper  800  may pass through the elongate stopper hole  120  and may move vertically along and in the elongate stopper hole  120 . 
     The stopper  800  may extend downwardly to be coupled to a bottom end of the cap  500 . The stopper  800  may move vertically in a spring-loaded manner. The stopper  800  may have a first stopper protrusion  810  projecting from a bottom end thereof. In one example, as shown in  FIG. 9 , the first stopper protrusion  810  may have a top portion with a right-angled inner step and a right-angled outer step. The first stopper protrusion  810  may be inwardly or outwardly move in an elastic manner. 
     When the cap  500  move upwards and thus the right-angled inner step of the first stopper protrusion  810  contacts a top edge of the elongate stopper hole  120 , the cap  500  may stop there. Thus, normally, the cap  500  may not be removed from the upper body  100 . Otherwise, the first stopper protrusion  810  is moved inwardly using a sharp object into the upper hollow body  100 , and, at this state, the cap  500  may be pulled upwards to remove the cap  500  from the upper body. In this way, the secondary elongate core  400  may be replaced. 
     To both opposing side faces of an upper portion of the cap  500 , two wheel shafts  610  may be coupled respectively. In this connection, each of the two wheel shafts  610  may extend in an oblique manner. To ends of the wheel shafts  610 , two guide wheels  600  may be coupled respectively to be rotatable. 
     Sizes of the guide wheels  600  may be configured such that while the guide wheels  600  contact the paper face, the cap  500  may be further inserted into the upper body by a certain distance, thereby to allow the tip portion of the secondary elongate core  400  to contact the paper face. 
     A material of the guide wheels  600  may be selected such that the guide wheels  600  may not slip along the paper to disallow drawing of a straight line. In this connection, factors to allow the guide wheels  600  to run in a straight line may include, for example, the wheel material being made of a rubber material with a high friction level; the wheel having an outer portion with small grooves formed along the outer portion to increase a friction force against the paper; an operation of running the wheel while pushing down the cap to increase a friction force against the paper; a suppression of the lateral movement of the wheel; a centering of the tip portion of the secondary core while contacting the paper, etc. 
     In one effective approach to increase a friction force against the paper, a shaft of each of the guide wheels  600  may extend to tilt toward the upper body  100 , and each of the guide wheels  600  encounters each of the wheel shafts  610  in a right angle, such that the two guide wheels  600  may be oriented not to be parallel with a length direction of the upper body  100  but be oblique relative to the length direction of the upper body  100 . Specifically, a virtual extension line in an orientation direction of each wheel may encounter the upper body as shown in  FIG. 9 . 
     Further, each of the guide wheels  600  may have a truncated conical shape. The shaft of each of the guide wheels  600  may extend to tilt toward the upper body  100 . In this way, the guide wheels  600  run in a straight line with more straightness. 
       FIG. 10  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the seventh embodiment of the present discourse. As shown in  FIG. 10 , the seventh embodiment may be different from the sixth embodiment in that two elongate stopper holes are formed to be spaced vertically from each other in the side portion of the body  100 , that is, the upper elongate stopper hole  120   a  and lower elongate stopper hole  120   b  are formed, and, correspondingly, the first stopper protrusion  810  includes an upper first stopper protrusion  810   a  and lower first stopper protrusion  810   b.    
     In this connection, the upper first stopper protrusion  810   a  is engaged into the upper elongate stopper hole  120   a  and the lower first stopper protrusion  810   b  is engaged into the lower elongate stopper hole  120   b . In this way, the cap  500  may move upwards and the secondary elongate core  400  may be entirely received in the cap  500  and upper hollow body  100 . Otherwise, when both the upper first stopper protrusion  810   a  and lower first stopper protrusion  810   b  are engaged into the lower elongate stopper hole  120   b , the cap  500  may move down and the tip portion of the secondary elongate core  400  may protrude out of the cap  500 . This configuration may be similar to the entrance or exit of the tip portion in the first core as described above. 
     In accordance with this embodiment, whether the second tip portion  420  is in a concealed or exposed state, the second tip portion in the concealed or exposed state may be fixed in a vertical position. Thus, during drawing an underline, the user needs not pushing the guide wheels  600  down against the paper face. 
       FIG. 11  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the eighth embodiment of the present discourse. As shown in  FIG. 11 , the eighth embodiment may be different from the sixth embodiment and seventh embodiment in that in place of the stopper  800  and first stopper protrusions  810   a  and  810   b , a cap protrusion  520 , body protrusions  150 , and a position limiter protrusion  160  may be disposed. 
     The cap  500  may have the cap protrusion  520  disposed in a ring shape at the bottom end thereof to protrude outwardly. The upper hollow body  100  may have two body protrusions  150  formed on an inner face thereof which may be vertically spaced from each other. Each of the two body protrusions  150  may protrude inwardly in a ring shape. The upper hollow body  100  may have a position limiter protrusion  160  formed on an inner face thereof below the lower body protrusion  150  at a given distance. The position limiter protrusion  160  may protrude inwardly in a ring shape. Via application of an external force above a given degree to the cap protrusion  520  and body protrusions  150 , the cap protrusion  520  overcomes the body protrusion  150  partially due to a rounded shape thereof. The position limiter protrusion  160  may stop the movement of the cap protrusion  520  partially due to an angled shape thereof. When the cap protrusion  520  is fitted between in the lower body protrusion  150  and the position limiter protrusion  160 , the cap  500  may be fixed in a position while the second tip portion  420  is exposed outwardly. In other words, the cap  500  may move vertically when the cap protrusion  520  is positioned between the two body protrusion  150 . In order to draw an underline, the guide wheels  600  is pushed against the paper face and thus the cap protrusion  520  is fitted between in the lower body protrusion  150  and the position limiter protrusion  160 , and, hence, the cap  500  may be fixed in a vertical position. During drawing the underline, the user needs not pushing the guide wheels  600  down against the paper face. 
       FIG. 12  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the ninth embodiment of the present discourse. As shown in  FIG. 12 , the ninth embodiment may be achieved by combining the sixth embodiment and eighth embodiment and removing the upper body protrusion  150  from the combination. In other words, the cap  500  may be position-fixed via the cap protrusion  520  being fitted between the lower body protrusion  150  and position limiter protrusion  160 , and the cap  500  may be prevented from being removed from the upper body using the stopper  800  and first stopper protrusion  810 . 
       FIG. 13  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the tenth embodiment of the present discourse. As shown in  FIG. 13 , in the tenth embodiment, two elongate stopper holes are formed to be spaced vertically from each other in a side portion of the upper hollow body  100 , that is, the upper elongate stopper hole  120   a  and lower elongate stopper hole  120   b  are formed. The stopper  800  may extend downwardly to be coupled to a bottom end of the cap  500 . The stopper  800  may be integrated with the cap  500 . The stopper  800  may move vertically in a spring-loaded manner. The stopper  800  may have a first stopper protrusion  810  projecting from a bottom end thereof. The first stopper protrusion  810  may move inwardly or outwardly in an elastic manner. The first stopper protrusion  810  may vertically move while engaged into the upper elongate stopper hole  120   a  and may be fixed in a position when engaged into the lower elongate stopper hole  120   b . The first stopper protrusion  810  may protrude from the stopper  800  outwardly. 
     When the first stopper protrusion  810  vertically moves while engaged into the upper elongate stopper hole  120   a  and reaches a top or bottom of the upper elongate stopper hole  120   a , the first stopper protrusion  810  may stop there, and, thus, the cap  500  also may stop there. When the first stopper protrusion  810  overcome the upper hollow body  100  and goes downs into the lower elongate stopper hole  120   b , the first stopper protrusion  810  may stop there, and, thus, the cap  500  also may stop there. 
     In other words, partially due to an angled shape of both the bottom and top of the first stopper protrusion  810 , when the cap  500  with the wheels is pushed against the paper face, the first stopper protrusion  810  may move down in and along the upper elongate stopper hole  120   a , and, then, may stop at a bottom of the upper elongate stopper hole  120   a . Via a release of the contacting force, the first stopper protrusion  810  may return to its original position due to the restoring force of the spring. However, the user may further push the cap  500  against the paper from the state in which the first stopper protrusion  810  stops at a bottom of the upper elongate stopper hole  120   a  while pushing the first stopper protrusion  810  inwardly, the first stopper protrusion  810  may be engaged into the lower elongate stopper hole  120   b  and thus the first stopper protrusion  810  stops there. In this state and is fixed in a position. In this fixed state, during drawing the underline, the user needs not pushing the guide wheels  600  down against the paper face. 
     A principal operation of the fourth embodiment to tenth embodiment will be describe as follows: 
     In a writing mode, a writing module including the lower hollow body  200  and primary elongate core  300  may be used to write the content. In an underline-drawing mode, the upper hollow body  100  may turn upside down and the cap or guide wheels  600  may be pushed up to enable the tip portion of the secondary elongate core  400  to protrude out of the cap though the second tip hole and to contact the paper face. Then, the user may move the wheels horizontally with gripping the upper hollow body  100  and thus the two guide wheels  600  may run along with the tip portion of the secondary elongate core  400  in a straight line, thereby to draw an underline in a straight line. 
     After drawing the underline, the user may not push the guide wheels  600 , and thus using the restoration force of the spring  700 , the cap  500  may return to its original position. Thus, the tip portion of the secondary elongate core  400  may be inserted back in the inner space in the cap  500 . 
       FIG. 14  shows a cross-sectional view of an underline-drawing module of a writing and underline-drawing implement in accordance with the eleventh embodiment of the present discourse. As shown in  FIG. 14 , the eleventh embodiment may be different from the fourth to tenth embodiments in that two secondary elongate cores  400  may be disposed side by side where the secondary elongate cores  400  may have different colors rendered. 
     In this embodiment, the two tip portions of the two secondary elongate cores  400  respectively may protrude out of the cap concurrently. However, when the upper hollow body  100  is tilted, only one of the two tip portions of the two secondary elongate cores  400  respectively may be used to draw one line. 
     In one embodiment, the secondary elongate core  400  may include a ball pen core. In one embodiment, the secondary elongate core  400  may include a non-ball type highlighter pen core. Since a tip portion of the non-ball type highlighter pen core may be dried due to a long time exposure to the air, a knock type highlighter pen is used. Specifically, in a non-use mode, the tip point of the non-ball type highlighter pen core is hidden. In a use mode, upon pressing of the core controller, an entrance of the tip point is opened, to allow the tip point of the non-ball type highlighter pen core to be extended out to be exposed. Then, upon further pressing of the core controller, the tip point of the non-ball type highlighter pen core to be retracted in to be concealed and then the entrance of the tip point is closed. Such a knock type highlighter pen is disclosed in details in the above patent document 2 and patent document 3, contents of which are incorporated herein by reference. 
     The above description is not to be taken in a limiting sense, but is made merely for the purpose of describing the general principles of exemplary embodiments, and many additional embodiments of this disclosure are possible. It is understood that no limitation of the scope of the disclosure is thereby intended. The scope of the disclosure should be determined with reference to the Claims. Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic that is described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment. 
     The present disclosure may have following industrial abilities. In accordance with the above writing and underline-drawing implement, both the writing and underline-drawing modes may be realized in a single pen. This may improve in-depth studies due to the fact that it may dispense the separate elongate straight object. Further, the present writing and underline-drawing implement may allow the user to quickly draw an underline in a straight line with improved straightness without the separate elongate straight object.