Abstract:
A puzzle pen of which the penholder is formed of a shaft holding a writing member for writing, puzzle rings mounted on the shaft each holding a plurality of axially slidable puzzle blocks, and a retaining device, which has a locating ring with a receiving groove for receiving one puzzle block from the puzzle rings for enabling the user to rearrange the combination of the puzzle blocks, a cover shell rotatably mounted on the shaft to close/open the receiving groove of the locating ring, and a spring member supported between the locating ring and the cover shell to force the locating ring against the puzzle rings.

Description:
BACKGROUND OF THE INVENTION 
   (a) Field of the Invention 
   The present invention relates to a pen and, more particularly, to a puzzle pen, which allows the user to play a picture puzzle. 
   (b) Description of the Prior Art 
   The penholder or barrel of a conventional writing implement, for example, a ballpoint pen, pencil, marker or color pen, has a fixed design, i.e., a user cannot change the outer design of the penholder or barrel of a writing implement. A writing implement of fixed outer design is monotonous. 
   U.S. Pat. No. 6,739,780, filed by the present inventor on Sep. 29, 2003, discloses a pen that has a plurality of ornamental rings that are rotatable individually to change the outer appearance of the penholder. 
   U.S. Pat. No. 6,966,717, filed by the present inventor on May 18, 2005, discloses a pen having a variable penholder. According to this design, a spring retainer is provided at one end of the penholder to hold ornamental rings against one another. When released from the spring retainer, the ornamental rings can be rotated to change the combination. 
   The aforesaid two prior art designs allow the user to rotate the ornamental rings individually so as to further change the outer appearance of the penholder. However, these two prior art designs do not allow the user to shift movable parts in longitudinal direction along the length of the penholder. 
   SUMMARY OF THE INVENTION 
   The present invention has been accomplished under the circumstances in view. According to one aspect of the present invention, the puzzle pen comprises a penholder formed of a shaft, a retaining device, and a plurality of puzzle rings. The shaft holds a writing member for writing. The puzzle rings are mounted on the shaft, each holding a plurality of axially slidable puzzle blocks. The retaining device comprises a locating ring with a receiving groove for receiving one puzzle block from the puzzle rings for enabling the user to rearrange the combination of the puzzle blocks, a cover shell rotatably mounted on the shaft to close/open the receiving groove of the locating ring, and a spring member supported between the locating ring and the cover shell to force the locating ring against the puzzle rings. According to another aspect of the present invention, the shaft has the top and bottom ends respectively mounted with a pen cap and a pen socket. According to another aspect of the present invention, the puzzle pen can be made in the form of a ballpoint pen, pencil, marker or color pen, or any of a variety of writing implement. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded view of a puzzle pen according to the present invention. 
       FIG. 2  is an elevational assembly view of the puzzle pen according to the present invention, showing the receiving groove of the locating ring being exposed to the outside. 
       FIG. 3  corresponds to  FIG. 2 , showing one puzzle block shifted from one puzzle ring into the receiving groove of the locating ring. 
       FIG. 4  is a schematic drawing of the present invention, showing the cover shell of the retaining device rotated through an angle to keep the receiving groove of the locating ring from sight. 
       FIG. 5  is an elevational view of the shaft of the puzzle pen according to the present invention. 
       FIG. 6  is an oblique top elevation of one puzzle ring for the puzzle pen according to the present invention. 
       FIG. 7  is an oblique bottom elevation of one puzzle ring for the puzzle pen according to the present invention. 
       FIG. 8  is an exploded view of one puzzle ring for the puzzle pen according to the present invention. 
       FIG. 9  is a cross sectional view of one puzzle ring for the puzzle pen according to the present invention. 
       FIG. 10  is a longitudinal sectional view of a part of the present invention, showing the receiving groove of the locating ring being exposed to the outside. 
       FIG. 11  is similar to  FIG. 10  but showing one puzzle block shifted into the receiving groove of the locating ring. 
       FIG. 12  is a longitudinal sectional view of the present invention, showing two puzzle rings separated. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1˜5 , a puzzle pen in accordance with the present invention is shown. It comprises a shaft  1 , a retaining device  2 , and a plurality of puzzle rings  3 . 
   The shaft  1  is a hollow member inserted through the retaining device  2  and the puzzle rings  3 , having a stop portion  11  at one end, namely, the bottom end, a first outer thread  111  extending around the periphery of the stop portion  11  for the mounting of a pen socket  4 , and a second outer thread  12  extending around the periphery of the other end, namely, the top end for the mounting of a pen cap  5 . 
   The retaining device  2  comprises a cover shell  21 , a spring member  22 , and a locating ring  23 . The cover shell  21  is sleeved onto the shaft  1  and stopped against the pen cap  5  to hold the spring member  22  and the locating ring  23  on the inside, having a side opening  211 . The locating ring  23  is sleeved onto the shaft  1  and stopped against the puzzle rings  3 , having at least one receiving groove  231  formed on the periphery and extending through the top and bottom sides. The spring member  22  is mounted inside the cover shell  21  and stopped between an inside wall of the cover shell  21  and one side of the locating ring  23  to force the locating ring  23  against the puzzle rings  3  and to push the puzzle rings  3  toward the stop portion  11  of the shaft  1 . 
   The puzzle rings  3  are sleeved onto the shaft  1  and stopped one against another between the stop portion  11  of the shaft  1  and the locating ring  23 . As shown in  FIGS. 6˜9 , each puzzle ring  3  comprises a body  31  and a plurality of puzzle blocks  32 . The body  31  has a plurality of locating grooves  311  formed on the periphery and extending through the top and bottom sides for receiving the puzzle blocks  32 , a plurality of coupling blocks  312  respectively protruded from the top side, and a plurality of coupling grooves  313  respectively formed on the bottom side. By means of coupling the coupling blocks  312  of the body  31  of one puzzle ring  3  to the coupling grooves  313  of the body  31  of another puzzle ring  3 , the puzzle rings  3  are connected in a stack. The puzzle blocks  32  can be made in any of a variety of shapes and colors or marked with any of a variety of signs. When the respective coupling blocks  312  of a first puzzle ring  3  are disengaged from the corresponding coupling grooves  313  of a second puzzle ring  3 , the two puzzle rings  3  can then be rotated relative to each other. 
   During the assembly process, the retaining device  2  and the puzzle rings  3  are sleeved onto the shaft  1 , and then a writing member  6  (ink cartridge and writing tip assembly or the like) is axially inserted into the shaft  1 , and then the pen socket  4  and the pen cap  5  are respectively threaded onto the first outer thread  111  and second outer thread  12  of the shaft  1 . 
   According to the present preferred embodiment, the body  31  of each puzzle ring  3  has a plurality of coupling blocks  312  respectively protruded from the top side and a plurality of coupling grooves  313  respectively formed on the bottom side. Alternatively, the body  31  of each puzzle ring  3  can be made to have a plurality of coupling blocks  312  at the bottom side and a plurality of coupling grooves  313  at the top side. Further, according to the present preferred embodiment, the pen socket  4  and the pen cap  5  are respectively fastened to the two distal ends by means of a respective screw joint. Any of a variety of other connection structures and means may be used to substitute for the screw joint. 
   As indicated above, the shaft  1  is a hollow member for accommodating the writing member  6 . Further, as shown in  FIG. 5 , the shaft  1  can be made having a plurality of coupling grooves  112  at the top portion  11  for receiving the coupling blocks  312  of one of the puzzle rings  3 . Alternatively, the shaft  1  can be made having a plurality of coupling blocks for engaging the coupling grooves  313  of one of the puzzle rings  3 . Further, the puzzle pen can be made in the form of an automatic pen or non-automatic pen. 
   When using the puzzle pen, rotate the cover shell  21  to have the side opening  211  in alignment with one receiving groove  231  of the locating ring  23  (see  FIGS. 2 and 10 ). At this time, the respective receiving groove  231  is exposed to the outside, and the corresponding puzzle block  32  of the first puzzle ring  3  can be moved into the receiving groove  231  of the locating ring  23  (see  FIGS. 3 and 11 ) to make the corresponding locating groove  311  available for receiving one puzzle block  32  of the second puzzle ring  3 . By means of shifting one puzzle block  32  from one puzzle ring  3  to one locating groove  231  of another puzzle ring  3 , the puzzle game is played. After the puzzle game is finished, the cover shell  31  is rotated through an angle to keep each receiving groove  231  of the locating ring  23  from sight, as in  FIG. 4 . 
   The main feature of the design of the present invention is to have the puzzle blocks  32  be respectively movable in longitudinal direction from one puzzle ring  3  to another and rotatable with the respective puzzle rings  3  in transverse direction so that the user can arrange the puzzle blocks  32  into one of a great number of combinations. 
   The retaining device  2  imparts a pressure to the puzzle rings  3  against the stop portion  11  of the shaft  1 , keeping the puzzle rings  3  abutted against one another. When pushing one puzzle ring  3  in longitudinal direction toward the retaining device  2  against the pen cap  5 , the retaining device  2  (the spring member  22 ) is compressed, and the respective puzzle ring  3  is disengaged from the next puzzle ring  3  for free rotation. 
   A prototype of puzzle pen has been constructed with the features of  FIGS. 1˜12 . The puzzle pen functions smoothly to provide all of the features disclosed earlier. 
   Although a particular embodiment of the invention has been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. For example, the puzzle pen can be made in the form of a ballpoint pen, pencil, marker, color pen, etc.; the shaft can be made having a stop portion at each of the two distal ends thereof for stopping the puzzle rings and the retaining device from falling out of the shaft. Accordingly, the invention is not to be limited except as by the appended claims.