Patent Document

BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a pencil, and more particularly, to a variable length pencil structure, which seals the inside of a pencil before using the pencil in order to prevent penetration of foreign materials in the air such as powder and dust into the pencil. 
     2. Description of the Related Art 
     Well known to those skilled in the art, a pencil used for makeup is taken in custody with its leading end being capped so that a brush in the leading end may not be exposed to powder or dust in the air. 
     However, since the pencil is separately provided with the cap, using the pencil requires an additional operation to remove the cap causing inconvenience to a user. 
     Further, if the cap is lost, the brush is exposed to the dust in the air. When this brush is kept in a handbag, there is a probability that the brush contacts with the inner surface of the handbag thereby contaminating the inside of the handbag. 
     In order to solve such a problem, Korean Patent Application Laid-Open No. 1998-72127 discloses a variable length pencil which exposes a brush through an opening of the pencil while placing the brush inside the pencil before using the pencil. 
     Although such a variable length pencil is excellent in an effect of varying the length of the pencil, however, the foreign materials may penetrate into the pencil through the opening in the lower end of the pencil resultantly leaving a probability that the brush contained within the pencil can be exposed to the dust. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention has been made to solve the foregoing problems and it is an object of the present invention to provide a variable length pencil structure which seals the inside of a pencil before using the pencil in order to prevent penetration of foreign materials in the air such as powder and dust into the pencil. 
     According to an aspect of the invention to obtain the above object, it is provided a variable length pencil comprising: a vertically opened rectangular inner housing; a power transmission unit fixedly provided inside the inner housing and having a rectangular body, a gear-receiving section of a certain width inside the body, a pinion rotatably provided by fixing means inside the gear-receiving section, with the gear-receiving section having both opened sides for outwardly exposing both sides of the pinion received in the gear-receiving section, guides provided at both sides of the body to oppose each other along the entire length thereof, wherein the both opened sides of the gear-receiving section respectively correspond to the guides; a first outer housing for sliding on the inner housing while contacting with the outside thereof; a head unit having a head fixed to one end of the first outer housing, a rack shaft inside thereof for cooperating with the power transmission unit and a flexible piece provided at a leading end of the rack shaft; a second outer housing fixedly provided around a lower end of the inner housing and having a closed lower end and a through hole in the closed lower end; and a movable unit movably provided inside the inner housing and having a rack shaft extended in a position opposed to the rack shaft of the head unit for cooperating with the power transmission unit and a fixed portion provided at a lower end for being exposed out of the second outer housing, wherein the rack shaft of the head unit and the rack shaft of the movable unit are respectively guided by the guides of the power transmission unit. 
     Preferably, the invention may further comprise: a guide member provided inside the second outer housing by coupling with the same, wherein the guide member has a guide at one side for guiding the flexible piece in a longitudinal direction and a lower end which is rounded to readily curve the flexible piece, whereby the flexible piece is readily moved and curved. 
     According to the invention, it is preferable that the power transmission unit is made of an elastic material and has incisions at upper both sides to impart flexibility to the upper both sides so that the power transmission unit is elastically supported to the inner wall of the inner housing. 
     Preferably, the invention may further comprise: a projection at the leading end of the rack shaft of the head unit, wherein the flexible piece is attached to the projection. 
     Also according to the invention, it is preferable that the second housing is rounded at a lower end of the inner wall thereof to readily curve the flexible piece toward the through hole of the second outer housing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a longitudinal sectional view illustrating a variable length pencil of the invention before it is used; 
     FIG. 2 is an exploded sectional view of the variable length pencil of the invention; 
     FIG. 3 is a sectional view along a line A—A in FIG. 1; 
     FIG. 4 is a sectional view along a line B—B in FIG. 1; 
     FIG. 5 is a magnification illustrating a region C in FIG. 1; 
     FIG. 6 is a magnification illustrating a region D in FIG. 1; 
     FIG. 7 is a perspective view illustrating a power transmission unit of the variable length pencil of the invention; 
     FIG. 8 is a perspective view illustrating a guide member of the variable length pencil of the invention; 
     FIG. 9 is a perspective view illustrating the external appearance of the pencil of the invention before it is used; 
     FIG. 10 is a longitudinal sectional view illustrating the pencil of the invention in use; and 
     FIG. 11 is a perspective view illustrating the external appearance of the pencil of the invention in use. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The following detailed description will present a preferred embodiment of the invention in reference to the accompanying drawings. 
     FIG. 1 is a longitudinal sectional view illustrating a variable length pencil of the invention before it is used, and FIG. 2 is an exploded sectional view of the variable length pencil of the invention. The variable length pencil of the invention is constituted of a rectangular inner housing  20 , the first and second outer housings  30  and  40  respectively arranged around the upper and lower portions of the inner housing  20 , a power transmission unit  70  fixedly installed inside the inner housing  20 , a head unit  10  fixedly installed in the upper portion of the inner housing  20  and a movable unit  50  moving inside the second outer housing  40 . 
     The first housing  30  is so mounted vertically slidable in respect to the inner housing  20  while contacting with the outside of the inner housing  20 . Further, within the inner housing  20  is mounted the power transmission unit  70 . FIG. 7 is a perspective view of the power transmission unit  70 , and FIGS. 3 and 4 are sectional views illustrating the installed position thereof. 
     The power transmission unit  70  is constituted of a box-shaped body  72  and a pinion  60  rotatably mounted by fixing means such as a pin  62  within the body  72 . Describing this in more detail, inside the body  72  is formed a gear-receiving section  74  with a predetermined width in which the pinion  60  is rotatably mounted by the fixing means such as the pin  62 . 
     Further, the gear-receiving section  74  has opened portions at both sides thereof so that both sides of the received pinion  60  are outwardly exposed through the opened portions. In the meantime, the body  72  is provided at both sides with guides  72   a  and  72   b  opposing each other along the entire length thereof. The both opened sides of the gear-receiving section  74  respectively correspond to the guides  72   a  and  72   b  so that those portions of the pinion  60  exposed through the opened portions are projected from the bottoms of the guides  72   a  and  72   b  as shown in FIG.  3 . 
     In the meantime, as specifically shown in FIG. 7, the power transmission unit  70  is composed of an elastic material and has slits  76  at opposite upper portions. As the remaining portions at both sides of the incisions  76  have flexibility, the power transmission unit  70  is elastically supported to the inner wall of the inner housing  20 . 
     Further, in the upper portion of the power transmission unit  70  are provided projections  78  so that the power transmission unit  70  can be fixed to the inner housing  20  without any separate fixing means after the power transmission unit  70  is inserted into the inner housing  20 . Further, at one end of the first outer housing  30  is preferably provided a fixing protrusion so that the projections  78  are caught to the first outer housing  30  to prevent the first outer housing  30  from being separated or detached from the inner housing  20 . 
     In the upper end of the first outer housing  30  is fixedly installed the head unit  10 . The head unit  10  has a head  12  and the first rack shaft  14  integrally extending downward from the head  12  for a predetermined length. The first rack shaft  14  extends through the first outer housing  30  to mesh with a portion of the pinion  60  of the power transmission unit  70  installed within the inner housing  20  so as to provide vertical transport movement. 
     That is to say, when the first outer housing  30  is coupled with the inner housing  20 , the first rack shaft  14  is placed within the guide  72   a  formed at one side of the body  72  constituting the power transmission unit  70  while a portion of the first rack shaft  14  is meshed with an exposed portion of the pinion  60  mounted within the gear-receiving unit  74  of the power transmission unit  70 . 
     The second outer housing  40  and the inner housing  20  are fixedly attached to each other at their ends, and the movable unit  50  is received within the second outer housing  40 . The brush  54  is fixed to the lower end of the movable unit  50 , and the second rack shaft  52  is extended from the upper end of the movable unit  50 . When the second outer housing  40  receiving the movable unit  50  is fixedly coupled with the inner housing  20 , the second rack shaft  52  of the movable unit  50  is placed within the guide  72   b  in the body  72  of the power transmission unit  70  to mesh with an exposed portion of the pinion  60  mounted within the gear-receiving section  74  of the power transmission unit  70 . 
     As shown in FIG. 1, the first rack shaft  14  fixed to the head unit  10  and the second rack shaft  52  fixed to the movable unit  50  are opposed to each other in respect to the pinion  60  of the power transmission unit while mesh with each other in respect to the pinion  60  so that the rack shafts  14  and  52  carry out their transport movements in the opposite direction to each other. The rack shafts  14  and  52  are respectively received within the guides  72   a  and  72   b  of the body  72  constituting the power transmission unit  70  so that each of the rack shafts  14  and  52  can be transported within the guides  72   a  and  72   b  to carry out correct linear transport. 
     As shown in FIGS. 1 and 2, in the leading end of the first rack shaft  14  of the head unit  10  is installed a flexible piece  18 . The flexible piece  18  is made of a flexible material to naturally curve when the leading end thereof contacts with a blind end having a through hole  42  of the second housing  40 . Further, as shown in FIG. 5, the first rack shaft  14  is provided with a projection  14   a  at a portion of the leading end thereof to which the flexible piece  18  is attached so that the elastic piece  18  closely contacts with the inner wall of the second outer housing  40  as well as the transport movement of the first rack shaft  14  imparts smooth sliding and inflection to the flexible piece  18 . 
     The projection  14   a  permits the flexible piece  18  to further closely contact with the inner wall of the second outer housing  40  to enable smooth sliding. Further, when the movable unit  50  is drawn out as the first outer housing  30  slidingly contacts with the outside of the inner housing  20 , the projection  14   a  is caught by the end of the inner housing  20  to prevent separation or detachment between the first outer housing  30  and the inner housing  20  due to excessive transport. 
     In the meantime, as shown in FIG. 6, lower edges of the second outer housing  40  are rounded so that the flexible piece  18  moves toward the through hole  42  of the second outer housing  40 . 
     Although the flexible piece  18  opens/closes the through hole  42  like this, it is preferred to add a guide member  80  for the purpose of a smooth opening/closing operation of the through hole  42 . Such a guide member  80  is specifically shown in FIGS. 1,  2  and  8 . 
     As can be seen from FIGS. 1 and 2, the guide member  80  is mounted inside the second outer housing  40  by coupling with the inner periphery thereof. 
     Further, FIG. 8 is a perspective view illustrating the guide member  80 . As can be seen from FIG. 8, the guide member  80  is provided with a guide  82  in the longitudinal direction at one side, and rounded at the end of the guide  82 . 
     Therefore, the flexible piece  18  is guided along the guide  82  of the guide member  80  without lateral transformation and its leading end is rounded to readily curve toward the closed end having the through hole  42  of the second outer housing  40 . 
     In the meantime, FIG. 9 is a perspective view illustrating the external appearance of the pencil before it is used, in which the first outer housing and the second outer housing  40  closely contact with each other, and the through hole  42  of the second outer housing  40  is closed by the flexible piece  18 . 
     Further, FIG. 11 is a perspective view illustrating the external appearance of the pencil in use, in which the first outer housing  30  is separated from the second outer housing  40  to increase the entire length of the pencil while projecting the brush  54  via the through hole  42  of the second outer housing  40 . 
     A process of operating the invention constructed as above will be described in reference to the drawings as follows. 
     FIG. 1 is the longitudinal sectional view illustrating the variable length pencil of the invention before it is used, and FIG. 10 is the longitudinal view illustrating the variable length pencil of the invention in use. 
     As can be seen in the drawings, when the head  12  of the head unit  10  is drawn upward, the first outer housing  30  is transported by sliding for a predetermined length in the same direction along the inner housing  20 . 
     Therefore, the first rack shaft  14  fixed to the end of the head  12  is moved upward, and the pinion  60  of the power transmission unit  70  is rotated with its one side being meshed with the first rack shaft  14 . 
     Like this, as the pinion is rotated, the second rack shaft  52  of the movable unit  50  meshed with the other side of the pinion  60  is transported downward in a direction opposite to the transport direction of the first rack shaft  14  of the head unit  10 . 
     Therefore, the movable unit  50  is transported downward within the second outer housing  40 , and as a result, the brush  54  of the movable unit  50  is transported downward for a predetermined distance to outwardly expose itself. 
     At the same time, the flexible piece  18  installed in the first rack shaft  14  of the head unit  10  retreats along the guide  82  of the guide member  80  to reside within the guide  82 . 
     The above operation is carried out just before the pinion  60  is released from each of the rack shafts  14  and  52  with which the pinion  60  is meshed or the projection  14   a  is caught by the inner housing  20 . 
     As shown in FIG. 10, upon completion of drawing out the movable unit  50 , the entire length of the pencil is increased as much as the transport distances of the rack shafts  14  and  52  added thereto. 
     After the pencil is used, an operation of placing the exposed brush  54  into the second outer housing  40  is carried out in a reverse manner as above. 
     That is, if the head  12  of the head unit  10  is pushed downward, the first outer housing  30  is transported downward as sliding on the inner housing  20 . This causes the first rack shaft  14  to move downward, and through this operation, the pinion  60  of the power transmission unit  70  is rotated reversely in respect to the rotating direction thereof when the first rack shaft  14  moves upward. 
     Further, as the pinion  60  is rotated, the second rack shaft  52  of the movable unit  50  meshed with the other side of the pinion  60  is transported upward in a direction opposite to the first rack shaft  14  of the head unit  10 . Therefore, the movable unit  50  is transported upward inside the second outer housing  40 , and as a result, the brush  54  which was exposed outside the second outer housing  40  is received into the second outer housing  40 . 
     At the same time, the flexible piece  18  attached to the leading end of the rack shaft  14  of the head unit  10  is moved along the guide  82  of the guide member  80  to close the through hole  42  in the lower end of the second outer housing  40 . 
     In this case, the flexible piece  18  is readily curved since the inner lower end of the second outer housing  40  is rounded. 
     According to the variable length pencil of the invention as set forth above, the brush is outwardly exposed as the entire length of the pencil is increased, but as the entire length of the pencil is decreased, the brush is received into the pencil making the same compact and the flexible piece closes the through hole of the second outer housing to prevent any penetration of dust in the air into the pencil. Therefore, there is an effect of advantageously further enhancing the convenience of the pencil in use. 
     Also, the invention can prolong the life time of the pencil by preventing the brush within the pencil from being exposed to dust and the like. 
     Further, the invention prevents the pencil from directly contacting with the external air so that the brush may not be dried. 
     Therefore, the brush can be maintained in a suitable degree of wetness so that a user can have smooth feeling to the brush in use.

Technology Category: 7