Automatic pencil assembly

Information

  • Patent Grant
  • 6767150
  • Patent Number
    6,767,150
  • Date Filed
    Friday, December 19, 2003
    20 years ago
  • Date Issued
    Tuesday, July 27, 2004
    19 years ago
Abstract
An automatic pencil assembly includes a barrel, a point, an urging member, two clamping members, a slide, a guide pipe, a lead, a cap, and a push member. Thus, the lead is pressed downward by the first plug or second plug of the push member to overcome the holding force of the clamping members, so that the lead is inserted into and protruded outward from the slide easily and conveniently.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to an automatic pencil assembly, and more particularly to an automatic pencil assembly, wherein the lead is pressed downward to overcome the holding force of the clamping members, so that the lead is inserted into and protruded outward from the slide easily and conveniently.




2. Description of the Related Art




A conventional automatic pencil in accordance with the prior art shown in

FIG. 16

comprises a barrel


100


, a point


200


mounted on a first end of the barrel


100


and having a first end formed with a sleeve


201


inserted into the first end of the barrel


100


, an urging member


203


secured in the sleeve


201


of the point


200


and having an inner wall formed with a tapered face


207


, two clamping members


202


each slidably mounted in the urging member


203


and having an outer wall formed with a cavity


204


for receiving a plurality of balls


205


which are urged on the tapered face


207


of the urging member


203


to contract the two clamping members


202


inward, a slide


300


slidably mounted in the point


200


and having a first end provided with a retaining race


400


and a second end protruded outward from a second end of the point


200


, a spring


206


mounted in the first end of the slide


300


and urged between the slide


300


and the clamping members


202


, a guide pipe


600


mounted in the barrel and rested on an end of the urging member


203


, a lead


500


in turn extended through the guide pipe


600


, the clamping members


202


, the retaining race


400


and the slide


300


and protruded outward from the slide


300


, and a cap


700


mounted on a second end of the barrel


100


and provided with an eraser


701


.




In operation, the cap


700


is removed from the barrel


100


, so that the lead


500


is placed into the barrel


100


. Then, the lead


500


is in turn extended through the guide pipe


600


, the clamping members


202


, the retaining race


400


and the slide


300


and protruded outward from the slide


300


. Thus, when the lead


500


is rested on a paper (not shown), the paper applies a reaction force on the slide


300


to draw the lead


500


outward from the slide


300


automatically.




However, the user needs to slightly shake the barrel


100


to facilitate the lead


500


sliding into the slide


300


, thereby causing inconvenience to the user. In addition, when the lead


500


has a greater length, the lead


500


is slightly bent due to its greater length, so that the lead


500


cannot pass through the slide


300


smoothly and is easily jammed or broken. Further, the barrel


100


cannot carry spare leads, thereby causing inconvenience to the user.




SUMMARY OF THE INVENTION




The primary objective of the present invention is to provide an automatic pencil assembly, wherein the lead is pressed downward by the first plug or second plug of the push member to overcome the holding force of the clamping members, so that the lead is inserted into and protruded outward from the slide easily and conveniently.




Another objective of the present invention is to provide an automatic pencil assembly, wherein the extension of the cap is used to store a plurality of spare leads, thereby facilitating the user carrying the leads.




A further objective of the present invention is to provide an automatic pencil assembly, wherein the rectangular guide hole of the guide pipe only allows passage of one lead, thereby preventing the leads from jamming.




A further objective of the present invention is to provide an automatic pencil assembly, wherein the guide pipe is formed be combining two semi-circular tubular together, so that the guide pipe is made easily and rapidly, thereby decreasing costs of fabrication.




A further objective of the present invention is to provide an automatic pencil assembly, wherein the rectangular guide hole of the guide pipe facilitates passage of the lead, so that the lead is moved in the rectangular guide hole of the guide pipe smoothly and conveniently.




A further objective of the present invention is to provide an automatic pencil assembly, wherein the first end of the barrel is formed with an inner thread, and the sleeve of the point is formed with an outer thread screwed into the inner thread of the barrel, so that the point is combined with the barrel easily and conveniently.




In accordance with the present invention, there is provided an automatic pencil assembly, comprising:




a barrel, a point, an urging member, two clamping members, a slide, a guide pipe, a lead, a cap, and a push member, wherein:




the barrel has a first end and a second end;




the point is mounted on the first end of the barrel and has a first end formed with a sleeve inserted into the first end of the barrel;




the urging member is mounted in the first end of the barrel and is secured in the sleeve of the point;




each of the two clamping members is slidably mounted in the urging member;




the slide is slidably mounted in the point and has a first end provided with a retaining race and a second end protruded outward from a second end of the point;




the guide pipe is mounted in the barrel and is rested on an end of the urging member;




the lead is in turn extended through the guide pipe, the clamping members, the retaining race and the slide and has a first end protruded outward from the guide pipe and a second end protruded outward from the slide;




the cap is mounted on the second end of the barrel and has an end formed with a cylindrical extension extended into the barrel; and




the push member is mounted on an end of the extension of the cap to seal the extension of the cap and is rested on the first end of the lead, the push member has a first end formed with a first plug that is insertable into the extension of the cap and a second end formed with a second plug that is insertable into the extension of the cap.




Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of an automatic pencil assembly in accordance with the preferred embodiment of the present invention;





FIG. 2

is a partially exploded perspective view of the automatic pencil assembly as shown in

FIG. 1

;





FIG. 3

is a partially enlarged view of a guide pipe of the automatic pencil assembly as shown in

FIG. 2

;





FIG. 4

is a plan cross-sectional view of the automatic pencil assembly as shown in

FIG. 1

;





FIG. 5

is a schematic operational view of the automatic pencil assembly as shown in

FIG. 4

;





FIG. 6

is another plan cross-sectional view of the automatic pencil assembly as shown in

FIG. 1

;





FIG. 7

is a partially perspective view of an automatic pencil assembly in accordance with another embodiment of the present invention;





FIG. 8

is a plan cross-sectional view of the automatic pencil assembly as shown in

FIG. 7

;





FIG. 9

is a partially enlarged view of the automatic pencil assembly as shown in

FIG. 8

;





FIG. 10

is a partially perspective view of an automatic pencil assembly in accordance with another embodiment of the present invention;





FIG. 11

is a plan cross-sectional view of the automatic pencil assembly as shown in

FIG. 10

;





FIG. 12

is a partially enlarged view of the automatic pencil assembly as shown in

FIG. 11

;





FIG. 13

is a plan cross-sectional view of an automatic pencil assembly in accordance with another embodiment of the present invention;





FIG. 14

is a plan cross-sectional view of an automatic pencil assembly in accordance with another embodiment of the present invention;





FIG. 15

is a schematic operational view of the automatic pencil assembly as shown in

FIG. 14

; and





FIG. 16

is a plan cross-sectional view of a conventional automatic pencil in accordance with the prior art.











DETAILED DESCRIPTION OF THE INVENTION




Referring to the drawings and initially to

FIGS. 1-4

, an automatic pencil assembly in accordance with the preferred embodiment of the present invention comprises a barrel


10


, a point


20


, an urging member


30


, two clamping members


41


, a slide


40


, a guide pipe


60


, a lead


50


, a cap


70


, and a push member


73


.




The barrel


10


has a first end and a second end.




The point


20


is mounted on the first end of the barrel


10


and has a first end formed with a sleeve


21


inserted into the first end of the barrel


10


.




The urging member


30


is mounted in the first end of the barrel


10


and is secured in the sleeve


21


of the point


20


. The urging member


30


has an inner wall formed with a tapered face


31


.




Each of the two clamping members


41


is slidably mounted in the urging member


30


and has an outer wall formed with a cavity


43


for receiving a plurality of balls


43


which are urged on the tapered face


31


of the urging member


30


to contract the two clamping members


41


inward.




The slide


40


is slidably mounted in the point


20


and has a first end provided with a retaining race


45


and a second end protruded outward from a second end of the point


20


. A spring


42


is mounted in the first end of the slide


40


and is urged between the slide


40


and the clamping members


41


.




The guide pipe


60


is mounted in the barrel


10


and is rested on an end of the urging member


30


. The guide pipe


60


has an inside formed with a rectangular guide hole


62


communicating with the two clamping members


41


and having an end formed with an arcuate guide portion


63


. Preferably, the guide pipe


60


consists of two semi-circular tubular


61


combined with each other.




The lead


50


is in turn extended through the guide hole


62


of the guide pipe


60


, the clamping members


41


, the retaining race


45


and the slide


40


and is protruded outward from the slide


40


.




The cap


70


is mounted on the second end of the barrel


10


and is provided with an eraser


71


. The cap


70


has an end formed with a cylindrical extension


72


extended into the barrel


10


.




The push member


73


is mounted on an end of the extension


72


of the cap


70


to seal the extension


72


of the cap


70


and has a first end formed with a first plug


74


that is insertable into the extension


72


of the cap


70


and a second end formed with a second plug


75


that is insertable into the extension


72


of the cap


70


. The first plug


74


of the push member


73


has an outer diameter equal to an inner diameter of the extension


72


of the cap


70


and is formed with a tapered hole


76


. The second plug


75


of the push member


73


has an outer diameter equal to the inner diameter of the extension


72


of the cap


70


. As shown in

FIG. 4

, the extension


72


of the cap


70


is used to store a plurality of spare leads


50


which are partially received in the tapered hole


76


of the first plug


74


of the push member


73


.




As shown in

FIG. 4

, the first plug


74


of the push member


73


is inserted into the extension


72


of the cap


70


, and the second plug


75


of the push member


73


is protruded outward from the extension


72


of the cap


70


.




When in use, referring to

FIGS. 1-5

, the cap


70


is removed from the barrel


10


, so that the lead


50


is guided through the guide portion


63


of the guide pipe


60


into the guide hole


62


of the guide pipe


60


. Then, the lead


50


is extended through the guide hole


62


of the guide pipe


60


and is slid into the clamping members


41


. Then, the cap


70


is mounted on the second end of the barrel


10


, with the second plug


75


of the push member


73


pressing the upper end of the lead


50


to overcome the holding force of the clamping members


41


, so that the lead


50


is in turn extended through the clamping members


41


, the retaining race


45


and the slide


40


as shown in

FIG. 5

, and is then protruded outward from the slide


40


for use as shown in FIG.


4


.




As shown in

FIG. 6

, the second plug


75


of the push member


73


is inserted into the extension


72


of the cap


70


, and the first plug


74


of the push member


73


is protruded outward from the extension


72


of the cap


70


, with the upper end of the lead


50


being received in the tapered hole


76


of the first plug


74


of the push member


73


, so that the automatic pencil is available for leads


50


of different length.




In operation, referring to

FIG. 4

, when a user exerts a downward force “A” on the cap


70


to press the lead


50


downward by the second plug


75


of the push member


73


, the clamping members


41


are moved downward through a small distance by the friction between the clamping members


41


and the lead


50


, so that the balls


43


are moved downward by the clamping members


41


to slide into a wider portion the tapered face


31


of the urging member


30


to release the clamping members


41


from the balls


43


, such that the clamping members


41


are slightly expanded outward by their elasticity.




Thus, the holding force of the clamping members


41


applied on the lead


50


is released, so that the lead


50


is in turn extended through the clamping members


41


, the retaining race


45


and the slide


40


as shown in

FIG. 5

, and is then protruded outward from the slide


40


for use as shown in FIG.


4


. At this time, the friction between the retaining race


45


and the lead


50


overcomes the gravity of the lead


50


, so that the lead


50


is positioned in place without further movement.




As shown in

FIG. 4

, when the lead


50


is rested on a paper “P”, the paper “P” applies a reaction force “B” on the lead


50


to move the lead


50


upward, so that the clamping members


41


are moved upward through a small distance by the friction between the clamping members


41


and the lead


50


.




In such a manner, the balls


43


are moved upward by the clamping members


41


to slide into a narrower portion the tapered face


31


of the urging member


30


to press the clamping members


41


inward, such that the clamping members


41


are contracted inward by the balls


43


to clamp the lead


50


, thereby stopping upward movement of the lead


50


. At this time, the balls


43


have a much shorter travel, so that the clamping members


41


and the lead


50


are moved upward through a very small distance, about 0.01 mm, so that the moving distance of the clamping members


41


and the lead


50


can be neglected without affecting the user's writing action.




Accordingly, the tapered face


31


of the urging member


30


, the clamping members


41


and the balls


43


form a oneway clamping mechanism, so that the lead


50


can be moved downward and cannot be moved upward. In addition, the slide


40


forms a sliding mechanism, so that when the slide


40


is subjected to the reaction force “B” of the paper “P”, the slide


40


is moved through a small distance to pull the lead


50


outward through a small length.




Referring to

FIGS. 7-9

, in accordance with another embodiment of the present invention, the urging member


30


is formed with a receiving recess


32


for receiving the guide pipe


60


.




Referring to

FIGS. 10-12

, in accordance with another embodiment of the present invention, the first end of the barrel


10


is formed with an inner thread


12


, and the sleeve


21


of the point


20


is formed with an outer thread


22


screwed into the inner thread


12


of the barrel


10


, so that the point


20


is combined with the barrel


10


easily and conveniently.




Referring to

FIG. 13

, in accordance with another embodiment of the present invention, the barrel


10


has an inside formed with a receiving chamber


11


for receiving the leads


50


. The receiving chamber


11


of the barrel


10


has a closed first end and an opened second end, and the eraser


71


is directly mounted on the opened second end of the receiving chamber


11


of the barrel


10


.




Referring to

FIGS. 14 and 15

, in accordance with another embodiment of the present invention, the automatic pencil assembly further comprises a movable pipe


80


movably mounted in the barrel


10


and formed with a through hole


82


, and a spring


83


mounted between the movable pipe


80


and the guide pipe


60


. Preferably, the guide pipe


60


has an outer wall formed with an annular mounting portion


64


for mounting a first end of the spring


83


, and the movable pipe


80


has an outer wall formed with an annular mounting portion


64


for mounting a second end of the spring


83


.




When the lead


50


has a shorter length as shown in

FIG. 14

, a new lead


50


is inserted into the through hole


82


of the movable pipe


80


. Then, the cap


70


is mounted on the second end of the barrel


10


as shown in

FIG. 15

, with the second plug


75


of the push member


73


pressing the upper end of the new lead


50


, so that the new lead


50


is inserted into the guide hole


62


of the guide pipe


60


. At the same time, the movable pipe


80


is pressed downward to overcome the elastic force of the spring


83


, so that the new lead


50


is moved downward to abut the smaller lead


50


as shown in FIG.


15


.




Accordingly, the rectangular guide hole


62


of the guide pipe


60


only allows passage of one lead


50


, thereby preventing the leads


50


from jamming. In addition, the guide pipe


60


is formed be combining two semi-circular tubular


61


together, so that the guide pipe


60


is made easily and rapidly, thereby decreasing costs of fabrication. Further, the rectangular guide hole


62


of the guide pipe


60


facilitates passage of the lead


50


, so that the lead


50


is moved in the rectangular guide hole


62


of the guide pipe


60


smoothly and conveniently. Further, the lead


50


is pressed downward by the first plug


74


or second plug


75


of the push member


73


to overcome the holding force of the clamping members


41


, so that the lead


50


is inserted into and protruded outward from the slide


40


easily and conveniently. Further, the extension


72


of the cap


70


is used to store a plurality of spare leads


50


, thereby facilitating the user carrying the leads


50


. Further, the first end of the barrel


10


is formed with an inner thread


12


, and the sleeve


21


of the point


20


is formed with an outer thread


22


screwed into the inner thread


12


of the barrel


10


, so that the point


20


is combined with the barrel


10


easily and conveniently.




Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.



Claims
  • 1. An automatic pencil assembly, comprising:a barrel, a point, an urging member, two clamping members, a slide, a guide pipe, a lead, a cap, and a push member, wherein: the barrel has a first end and a second end; the point is mounted on the first end of the barrel and has a first end formed with a sleeve inserted into the first end of the barrel; the urging member is mounted in the first end of the barrel and is secured in the sleeve of the point; each of the two clamping members is slidably mounted in the urging member; the slide is slidably mounted in the point and has a first end provided with a retaining race and a second end protruded outward from a second end of the point; the guide pipe is mounted in the barrel and is rested on an end of the urging member; the lead is in turn extended through the guide pipe, the clamping members, the retaining race and the slide and has a first end protruded outward from the guide pipe and a second end protruded outward from the slide; the cap is mounted on the second end of the barrel and has an end formed with a cylindrical extension extended into the barrel; and the push member is mounted on an end of the extension of the cap to seal the extension of the cap and is rested on the first end of the lead, the push member has a first end formed with a first plug that is insertable into the extension of the cap and a second end formed with a second plug that is insertable into the extension of the cap.
  • 2. The automatic pencil assembly in accordance with claim 1, wherein the first plug of the push member is formed with a tapered hole.
  • 3. The automatic pencil assembly in accordance with claim 2, wherein the extension of the cap receives therein a plurality of spare leads which are partially received in the tapered hole of the first plug of the push member.
  • 4. The automatic pencil assembly in accordance with claim 1, wherein the first plug of the push member has an outer diameter equal to an inner diameter of the extension of the cap.
  • 5. The automatic pencil assembly in accordance with claim 1, wherein the second plug of the push member has an outer diameter equal to an inner diameter of the extension of the cap.
  • 6. The automatic pencil assembly in accordance with claim 1, wherein the first plug of the push member is inserted into the extension of the cap, and the second plug of the push member is protruded outward from the extension of the cap and is rested on the first end of the lead.
  • 7. The automatic pencil assembly in accordance with claim 1, wherein the second plug of the push member is inserted into the extension of the cap, and the first plug of the push member is protruded outward from the extension of the cap and is rested on the first end of the lead.
  • 8. The automatic pencil assembly in accordance with claim 1, wherein the urging member is formed with a receiving recess for receiving the guide pipe.
  • 9. The automatic pencil assembly in accordance with claim 1, wherein the first end of the barrel is formed with an inner thread, and the sleeve of the point is formed with an outer thread screwed into the inner thread of the barrel.
  • 10. The automatic pencil assembly in accordance with claim 1, wherein the barrel has an inside formed with a receiving chamber for receiving the lead.
  • 11. The automatic pencil assembly in accordance with claim 1, wherein the receiving chamber of the barrel has a closed first end and an opened second end, and the automatic pencil assembly further comprises an eraser mounted on the opened second end of the receiving chamber of the barrel.
  • 12. The automatic pencil assembly in accordance with claim 1, further comprising a movable pipe movably mounted in the barrel and formed with a through hole for passage of the lead, and a spring mounted between the movable pipe and the guide pipe.
  • 13. The automatic pencil assembly in accordance with claim 12, wherein the guide pipe has an outer wall formed with an annular mounting portion for mounting a first end of the spring, and the movable pipe has an outer wall formed with an annular mounting portion for mounting a second end of the spring.
  • 14. The automatic pencil assembly in accordance with claim 1, wherein the urging member has an inner wall formed with a tapered face, and each of the two clamping members has an outer wall formed with a cavity for receiving a plurality of balls which are urged on the tapered face, so that the balls are moved by the clamping members between a first position where the balls are rested on a narrower portion the tapered face of the urging member to press the clamping members inward, and a second position where the balls are rested on a wider portion the tapered face of the urging member to release the clamping members from the balls.
  • 15. The automatic pencil assembly in accordance with claim 1, further comprising a spring mounted in the first end of the slide and urged between the slide and the clamping members.
  • 16. The automatic pencil assembly in accordance with claim 1, wherein the guide pipe has an inside formed with a rectangular guide hole communicating with the two clamping members, and the lead is extended through the guide hole of the guide pipe.
  • 17. The automatic pencil assembly in accordance with claim 1, wherein the guide pipe consists of two semi-circular tubular combined with each other.
US Referenced Citations (3)
Number Name Date Kind
3947133 Kageyama et al. Mar 1976 A
4538934 Brunner Sep 1985 A
6254296 Sheu Jul 2001 B1