Abstract:
Au automatic pencil comprising an outer pencil tube, a pencil head, a clipping device, a guiding tube and a pencil lead cylinder, characterized in that a resilient element is mounted between the guiding tube and the clipping device allowing the guiding tube to reciprocate upward and downward within the stopper. The resilient element urges the guiding tube to rise upward if the pencil lead cylinder is not depressed, and to keep a distance from the pencil lead, and to allow another pencil lead to be inserted. The pencil lead cylinder can adapt a plurality of pencil lead.

Description:
BACKGROUND OF THE INVENTION 
   (a) Technical Field of the Invention 
   The present invention relates to automatic pencil, and in particular, an automatic pencil allowing vertically depressing of a pencil lead to protruded from the tip of the automatic pencil. 
   (b) Description of the Prior Art 
     FIG. 1  is a conventional automatic pencil. The pencil has a hollow pencil shaft  1  having a bottom end linked to a pencil head  10 . The center region of the pencil head  10  is being mounted with a pencil tip  11 . The pencil head  10  is extended to mount a mounting cylinder  100  and is positioned with a pencil shaft. The pencil tip  11  is a banding ring  110  having frictional force to pull a pencil lead  12 . A stopper is provided on the pencil tip  11  which is formed from two semi-circular stopping plates  13 . The bottom end is extended until the slot within the top end of the pencil tip  11  and is mounted with a spring  14 , allowing the pencil tip  11  to reciprocate upward and downward. 
   The bottom section of the stopping plates  13  is a slot  131  for the mounting of rolling ball  15 , and is in combination with the inner wall of the inner cylinder  16 . The top section of the inner cylinder  16  is mounted with a guiding tube  17  and the utmost end has a capping body  18 . The top end of the capping body is an eraser  181 . 
   Pencil leads  12  are inserted via the guiding tube  17 . When the pencil leads  12  are depressed downwardly to the stopping plates  13 , the depression of the pencil tip  11  when writing will automatically push out the pencil lead  12  without any other operation action, and can continuously in writing, which is very convenient in application. Conventional pencil leads are generally very long and when pencil leads are placed within the guiding tube  17 , there is no any device to downward depress of the pencil leads, therefore the pencil shaft  1  has to be shaked so that the lead will side down to the stopping plate  13  and via the depressed pencil tip  11 , the compression spring  14  causes the pencil tip  11  to inwardly contracted into the pencil shaft  1 . When depression force is released, the spring  14  causes the tip  11  to protrude out from the pencil head  10  and at the same time, a pencil is withdraw at a great length. Repeating the action for several times, the pencil lead  12  is pushed out for utilization. 
   Whether or not there are pencil leads  12  contains in the pencil shaft  1 , it can not be seen from outside of the pencil shaft  1 , even the remaining of the lead cannot be determined. Thus, when the user opens the capping body  18  and inserts another pencil lead, the guiding hole  19  may be blocked and the pencil lead  12  is broken or is being blocked. In the conventional automatic pencil, no pencil lead cylinder is provided to the pencil shaft  1  and therefore, the pencil shaft  1  cannot hold extra pencil leads. 
   SUMMARY OF THE INVENTION 
   The primary purpose of the present invention is to provide an automatic pencil comprising an outer pencil tube, a pencil head, a clipping device, a guiding tube and a pencil lead cylinder, characterized in that a resilient element is mounted between the guiding tube and the clipping device allowing the guiding tube to reciprocate upward and downward within the stopper. 
   A further object of the present invention is to provide an automatic pencil, wherein the pencil lead cylinder has a sealing cap having an end face forming into a guiding arch surface. 
   Yet a further object of the present invention is to provide an automatic pencil, wherein the top end face of the guiding tube is formed into a guiding arch surface which is extended to a through hole formed at the center of the guiding tube. 
   Still a further object of the present invention is to provide an automatic pencil, wherein the guiding tube is provided with a hollow guiding shaft. 
   Yet still an object of the present invention is to provide an automatic pencil, wherein the bottom end of the guiding shaft is downwardly formed into a guiding hole. 
   An advantage of the present invention is that the resilient element  50  mounted between the guiding tube  6  and the clipping device  5  allows the insertion of a second pencil lead  40 , and the pencil lead  40  will not be engaged at the arch surface  62 . 
   Yet another advantage is that the pencil lead cylinder  4  can contain a plurality of pencil lead  40  and can be inserted to the pencil shaft  2 . 
   Still another advantage is that the pencil lead cylinder can be replaced with a new one. 
   Further advantage of the present invention is that the lead is guided by the arch surface  421  and the pencil lead  40  is moved vertically downward without breaking. 
   Still a further advantage of the invention is that when the guiding rod  64  is depressed, the pencil lead can be guided to the pencil shaft  2  via the guiding hole  641  and smoothly passes through the through hole  63  of the guiding tube without engagement or breaking the pencil lead  40 . 
   The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts. 
   Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a sectional view of a conventional automatic pencil. 
       FIG. 2  is a perspective view of an automatic pencil in accordance with the present invention. 
       FIG. 3  is a perspective exploded view of an automatic pencil in accordance with the present invention. 
       FIG. 4  is a perspective view of the pencil lead cylinder in accordance with the present invention. 
       FIG. 5  is an exploded perspective view of the pencil leads cylinder in accordance with the present invention. 
       FIG. 6  is a perspective view showing the change of the pencil lead cylinder in accordance with the present invention. 
       FIG. 7  is a perspective view showing the movement of the pencil lead within the pencil lead cylinder of the present invention. 
       FIGS. 8 and 9  are sectional views indicating the pencil lead within the pencil lead cylinder of the present invention. 
       FIG. 10  is a sectional view showing the stopping of the pencil lead within the pencil lead cylinder of the present invention. 
       FIG. 11  is a schematic view showing the withdrawal of the pencil lead cylinder of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims. 
   The present invention will now be described in connection with  FIG. 2 . There is shown an automatic pencil comprising a pencil shaft  2 , a pencil head  3 , a pencil lead cylinder  4  and a clipping device  5  within the pencil shaft  2 , and a guiding tube  6 , and a resilient element  50  mounted thereto. The pencil head  3  is connected to the bottom end of the pencil shaft  2  such that the pencil tip  30  is protruded out of the pencil head  3 , and the pencil lead cylinder  4  at the top end is inserted into the hollow interior of the pencil shaft  2 . As regards to the structure of the guiding tube  6  and the clipping device  5  and the resilient element,  FIG. 3  indicates this structure. The top end of the pencil head  3  is connected to the clipping device  5  and the resilient element  50  is mounted onto the clipping device  5  and is then mounted with the guiding tube  6  such that the resilient element  50  is connected between the mounting rod  61  of the guiding tube  6  and the combination rod  51  of the clipping device  5  which can press the resilient element  50  onto the combination rod  51  to cause an upward and downward movement, and the top end face of the guiding tube  6  is provided with a guiding arch face  62  and the center of the guiding tube  6  is a through hole  63  allowing the pencil lead  40  to pass through. A guiding rod  64  is positioned within the guiding tube  6  and formed with a guiding hole  641 . Further, the pencil lead cylinder  4  matches the pencil shaft  2  which has a hollow interior. The upper or top end of the cylinder  4  is an end head  41  which has a top end for mounting an eraser  410 . The bottom end of the cylinder  4  is a sealing cap  42  to cap the pencil leads for spare use. 
   As shown in  FIG. 4 , the resilient element  50  is connecting the clipping device  5  and the guiding tube  6  and the clipping device  5  is connected on the top end of the pencil head  3 , and the combined structure is inserted to the bottom end of the pencil shaft  2 . The pencil lead cylinder  4  is tubular having the top end being the end head  41  which can be engaged at the top end of the pencil shaft  2 . The top end of the end head  41  is mounted with an eraser  410 , and the bottom end of the pencil lead cylinder  4  is a sealing cap  42  which could vertically hold the pencil lead  40 . 
   As shown in  FIG. 5 , there is shown the structure of the pencil lead cylinder  4 . The pencil lead cylinder  4  has an end head  41  which can hold an eraser  410 . The sealing cap  42  can be uncapped, and the end side is a guiding arch surface  421 . When the sealing cap  42  is withdrawn, the pencil lead  40  can be inserted via the through hole  431  of the mounting rod  43  and is then capped by the sealing cap  42 , which can hold a plurality of spare pencil leads  40 . When the pencil lead cylinder  4  is inserted into the top end of the pencil shaft  2  as shown in  FIG. 6 , the end head  41  or the eraser  410  may be damaged if it is bitten (by children). At this instance, only the pencil lead cylinder  4  is replaced. 
   Referring to  FIG. 7 , when in use, the pencil lead cylinder  40  is pulled out, disengaged from the through hole  20  of the pencil shaft  2  and the pencil lead  40  is inserted through the through hole  20 , and then the pencil lead cylinder  4  is inserted and the sealing cap  42  is capped to depress the pencil lead  40 . Thus, the insertion of pencil lead  40  is complete. 
     FIGS. 8-11  show the movement of the insertion of pencil lead  40  in accordance with the present invention. When the pencil lead  40  is inserted into the interior of the pencil shaft  2  (shown in  FIG. 8 ), one end of the pencil lead  40  will directly contact the guiding arch surface  62  at the top end of the guiding tube  6 . Due to the slanting angle of the arch surface  62 , the end section of the pencil lead  40  is guided to the through hole  63  (referring to  FIG. 9 ). At this point of time, when the pencil lead cylinder  4  is inserted, the sealing cap  42  is lowered to contact the other end of the pencil lead  40 . The guiding arch surface  421  guides the end portion of the pencil lead  40  to the center region (as shown in  FIG. 10 ) so that the pencil lead  40  is in a vertical position. Thus, when the top end is depressed, the pencil lead end  40  urged at the through hole  63  of the guiding tube  6  depresses the guiding tube  6 , and the resilient element  50  is compressed until the guiding tube  6  cannot be lowered. Due to the continuous depression force on the pencil lead  40 , it will pass through the guiding shaft  64  of the guiding tube  6  and to the through hole at the center of the combination rod  51  of the clipping device  5 , and is lowered to the pencil head  3 . The length of the pencil lead  40  can be set such that when the pencil lead cylinder  4  is depressed at the end portion, the pencil lead  40  is protruded from the pencil tip  30  sufficient for writing. If the pencil lead  40  is not pushed out from the pencil tip  30  or if the lead  40  is ended, the depression while writing will slowly withdraw the pencil lead. Thus, when the pencil lead  40  is inserted, no depression is needed the pencil lead  40  will continuously push out after the pencil lead  40  is used. 
   When the pencil lead  40  is to be used completely, and a new pencil lead  40  is inserted, as shown in  FIG. 11 , the pencil lead cylinder  4  is withdrawn from the end head  41 , the depression force on the guiding tube  6  is disappeared. The restoration of the resilient element  50  causes the guiding tube  6  to move upward to keep a distance from the original pencil lead  40 . The space allows a new pencil lead  40  to be inserted. When the guiding tube  6  is depressed, due to the distance between the pencil lead and the combination rod  51 , the original pencil lead  40  will not align with the through hole  63 . In accordance with the present invention, the guiding rod  64  is mounted within the guiding tube  6  and the guiding rod  64  is hollow, the top end aligns with the through hole  63 , and the bottom end is formed into a guiding hole  641 . When the guiding rod  64  is depressed till the end head of the pencil lead  40 , the guiding hole  641  will lead the pencil lead to the hollow interior of the guiding rod  64 , and passes along the guiding hole  63  of the guiding tube. The pencil lead  40  will not be broken or engaged. Repeating the depress movement will push out the pencil lead  40  of the pencil tip  30  for writing. 
   It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above. 
   While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention.