Abstract:
A multi-color writing instrument such as a ballpoint pen or mechanical pencil, which is adapted such that a selection of a writing color can be easily performed even under poor lighting conditions and/or by a person with poor eyesight. The writing instrument includes a plurality of reservoir tubes containing different writing colors, which are accommodated in a barrel. Operating portions are provided on the reservoir tubes and exposed outside the barrel. The operating portions can be differentiated from each other by touch. Thereby a specific one of the reservoir tubes can be selected by the operating portions for use.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
   The invention relates to a writing instrument such as a ballpoint pen or mechanical pencil, having plural reservoir tubes possessing different writing colors. 
   A two-color ballpoint pen of different colors, for example, of black and red and a multiple-color ballpoint pen in which a suitable color such as blue is added to the former colors, or a writing instrument in which a ballpoint pen and a mechanical pencil are integrated has been widely known. 
   In case where an optional writing color is selected from plural different writing colors, it is selected by an operating portion relating to each writing color. However, since the operating portion has the same shape for all writing colors, the selection of the writing color has been exclusively performed only by a visual confirmation. Therefore, a person with poor eyesight can not use it and, even for people in general, the selection of the writing colors has been difficult when writing such as memorandum in a gloom place. 
   OBJECTS OF THE INVENTION 
   It is an object of the present invention to provide an improved multi-color writing instrument such as a ballpoint pen or mechanical pencil. Another object of the present invention is to provide a multi-color writing instrument such as a ballpoint pen or mechanical pencil, which permits easy recognition and judgment in the selection of a specific color, prevents an error of discrimination in a gloomy place or the like for users in general, and which allows users with poor eyesight to easily select a writing color. 
   SUMMARY OF THE INVENTION 
   These and other objects are attained in accordance with the present invention by a writing instrument adapted such that plural reservoir tubes having different writing colors are accommodated in a barrel, operating portions provided in the reservoir tubes are exposed outside the barrel, and any of the reservoir tubes is selected by the operating portion associated and used, in which touch feelings of the operating portions of the reservoir tubes are mutually differentiated. 
   According to preferred embodiment of the invention the external shapes of the operating portions of the reservoir tubes are mutually differentiated in order to provide different touch feelings to the operating portions. 
   According to another preferred embodiment of the invention convex portions or concave portions are provided in the operating portions, and the shapes of the convex portions or the concave portions in the operating portions of the reservoir tubes are mutually differentiated. 
   According to still another preferred embodiment of the invention convex portions or concave portions are provided in the operating portions, and the number of the convex portions or the concave portions in the operating portions of the reservoir tubes are mutually differentiated. 
   According to still another preferred embodiment of the invention convex portions or concave portions are provided in the operating portions, and the positions of the convex portions or the concave portions in the operating portions of the reservoir tubes are mutually differentiated. 
   Preferably the hardness of the operating portions of the reservoir tubes are mutually differentiated in order to provide different touch feelings to the operating portions. 
   Further preferably plural writing instruments in which the writing colors are differentiated for every writing instrument are made into one set, and the touch feelings of the operating portions of the writing instruments belonging to that set are mutually differentiated. 
   Further preferably the writing instrument is a ballpoint pen or a mechanical pencil. 
   According to another aspect of the present invention a writing instrument is provided which includes a number of reservoir tubes of different writing colors accommodated in a barrel, and a similar number of operating portions connected with the reservoir tubes, each for actuating a specific reservoir tube, said operating portions being exposed outside the barrel, each operating portion having a touch feeling means, the touch feeling means of each operating portion at least by one of the shape, hardness and position thereof being different from that of the touch feeling means of the other operating portions for differentiating by touch a specific one of the said operating portions for selecting one of the reservoir tubes for writing use. 
   Still according to another aspect of the invention a set of writing instruments is provided, in which each writing instrument includes a number of reservoir tubes of different writing colors accommodated in a barrel, and a similar number of operating portions connected with the reservoir tubes, each for actuating a specific reservoir tube, said operating portions being exposed outside the barrel, each operating portion having a touch feeling means, the touch feeling means of each operating portion at least by one of the shape, hardness and position thereof being different from that of the touch feeling means of the other operating portions for differentiating by touch a specific one of the said operating portions for selecting one of the reservoir tubes for writing use, each writing instrument further including further touch feeling means provided on the operating portions for differentiating the writing instruments of the set with each other. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be explained in more detail hereinafter with reference to the drawings and embodiments thereof. In the drawings: 
       FIG. 1  is a right side view showing a writing instrument according to an embodiment of the invention; 
       FIG. 2  is a sectional view along a line II—II in  FIG. 1 ; 
       FIG. 3  is a plan view of the embodiment of the invention shown in  FIG. 1 ; 
       FIG. 4  is a perspective view showing a detail of the embodiment of the invention shown in  FIG. 1  to  FIG. 3  illustrating the operating portions provided with three reservoir tubes being detached; 
       FIG. 5  is a perspective view similar to  FIG. 4  of a first modification of the operating portions; 
       FIG. 6  is a perspective view similar to  FIG. 4  of a second modification of the operating portions; 
       FIG. 7  is a perspective view similar to  FIG. 4  of a third modification of the operating portions; 
       FIG. 8  is a perspective view similar to  FIG. 4  of a fourth modification of the operating portions; 
       FIG. 9  is a perspective view similar to  FIG. 4  of a fifth modification of the operating portions; 
       FIG. 10  is a perspective view similar to  FIG. 4  of a sixth modification of the operating portions; 
       FIG. 11  is a perspective view similar to  FIG. 4  of a seventh modification of the operating portions; and 
       FIG. 12  is a perspective view similar to  FIG. 4  of an eighth modification of the operating portions. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  is a right side view showing an embodiment in which the invention is applied to a three-color ballpoint pen,  FIG. 2  a sectional view along a line II—II in  FIG. 1 , and  FIG. 3  a plan view. 
   A ballpoint pen  1  basically comprises a barrel  4  having an opening  2  at its front end and a clip  3  at its rear portion, and three reservoir tubes  5  accommodated in the barrel  4 . 
   The reservoir tube  5  includes a tubular ink storage portion  6  for storing an ink therein, a tip  7  and an operating portion attaching piece  8  respectively attached to its front end and rear end. An operating portion  9  is provided in a rear side face of the operating portion attaching piece  8 . 
   In the respective ink storage portions  6  of the tree reservoir tubes  5 , inks different in writing colors, e.g., black, red and blue are respectively stored. 
   In a front end of the tip  7 , a ball  10  for transferring the ink to a paper surface or the like is held such that a front end of the ball  10  is exposed. 
   The operating portion  9  is exposed outside from an axial slide hole  11  provided in a rear side face of the barrel  4 . If the reservoir tube  5  of the desired writing color is selected and the operating portion  9  is slid forward by one of the operating portions  9  respectively provided in the three reservoir tubes  5  in which the inks different in writing colors are stored, the front end of the tip  7  of the selected reservoir tube  5  is exposed outside from the opening  2  of the barrel  4 , so that a state ready for use is obtained. 
   After finishing the writing, by slightly sliding forward the operating portion  9  relating to any one of the other reservoir tubes  5  which have not been selected in the above, or by pushing the clip  3  in a center direction of the barrel  4 , the tip  7  selected and exposed outside is automatically accommodated in the barrel  4  by an action of a not-shown spring or the like. 
   A so-called feeding mechanism of the reservoir tube  5  in a ballpoint pen or the like, in which the front end of the tip  7  of the reservoir tube  5  relating to the selected writing color is put in and out from the opening  2  of the barrel  4  by the operation of the operating portion  9  in this manner, is well-known and widely used. 
   In this specification, although an explanation about the feeding mechanism is omitted in order to avoid a redundancy, the well-known feeding mechanism can be optionally used. 
   The invention is characterized in that the touch feeling of the operating portions  9  relating to the three reservoir tubes  5  different in the writing colors are mutually differentiated. 
   As concrete means for mutually differentiating the touch feelings, there is enumerated a form in which the external shapes or hardness of the operating portions are mutually differentiated. 
   Among these, as a typical means for differentiating the external shapes, there is enumerated a form in which a convex portion or a concave portion is provided in a surface of the operating portion  9 , and any of shape, number and position of the convex portion or the concave portion in the operating portion  9  of each reservoir tube  5  is differentiated. 
   Hereunder, it is concretely explained about this. 
     FIG. 4  is a perspective view of the operating portions  9  provided in the three reservoir tubes  5  being detached of a ballpoint pen  1  shown in  FIG. 1  to FIG.  3 . Each of the operating portions  9   a ,  9   b  and  9   c  has a small plate-like form long in an axial direction of the barrel  4 , and its rear portion is inwardly curved. 
   In a rear face of the operating portion  9 , there are provided two attaching protrusions  13  in a back-and-forth direction. The operating portion  9  is attached to the reservoir tube  5  by fitting the attaching protrusions  13  to fitting holes  14  of an operating portion attaching piece  8  (see  FIG. 2 ) in the reservoir tube  5 . In respective surfaces of the three operating portions  9 , convex portions are provided, namely a single central protrusion  16  of essentially triangle shape in side view is provided on a first operating portion  9   a , two protrusions  17  of a same triangle shape are provided spaced from each other in the back-and-forth direction on a second operating portion  9   b , and a single central protrusion  18  of trapezoid shape in side view is provided on a third operating portion  9   c.    
   In this manner, by mutually differentiating the numbers or shapes of the protrusions  16 ,  17  and  18  of the operating portions  9   a ,  9   b  and  9   c  of the reservoir tubes  5  different in writing colors, the desired writing color can be easily selected even in a gloomy place or by even a person with poor eyesight, owing to the different touch feelings in operating the operating portions  9   a ,  9   b  and  9   c  by a finger, e.g., thumb, of a hand to thereby allow it to be used. 
   FIG.  5  and  FIG. 6  are views showing another embodiment and corresponding to FIG.  4 . 
   In this embodiment, a first ballpoint pen having operating portions  19   a ,  19   b  and  19   c  shown in  FIG. 5 and a  second ballpoint pen having operating portions  20   a ,  20   b  and  20   c  shown in  FIG. 6  are made into one set. 
   The first ballpoint pen has different writing colors from the three writing colors of the second ballpoint pen, and therefore total six writing colors are differentiated to be used. 
   The operating portions  19   a ,  19   b  and  19   c , and  20   a ,  20   b  and  20   c  of the first and second ballpoint pens are respectively provided with protrusions  21 ,  22  and  23 , and  24 ,  25  and  26  similar to the case shown in FIG.  4 . 
   The operating portions  19   a ,  19   b  and  19   c , and  20   a ,  20   b  and  20   c  of the first and second ballpoint pens are additionally provided with discriminating elements  27  and  28  mutually different in their touch feelings in order to discriminate the first ballpoint pen from the second ballpoint pen. 
   That is, each of the operating portions  19   a ,  19   b  and  19   c  of the first ballpoint pen is provided in a surface of its curved portion  29  with one pen type discriminating protrusion  30 , and each of the operating portions  20   a ,  20   b  and  20   c  of the second ballpoint pen is provided in a surface of its curved portion  31  with two pen type discriminating protrusions  32 . 
   A user can easily discriminate the first ballpoint pen from the second ballpoint pen owing to the difference in the touch feeling of the pen type discriminating protrusions  30  and  32 . 
   Generally, by making plural (for example, three or more) ballpoint pens whose writing colors are different each other into one set and by mutually differentiating the touch feelings of the operating portions of the respective ballpoint pens belonging to that set, desired writing color can be easily selected from among the many writing colors over the plural ballpoint pens to thereby present it for use, similarly to the embodiment shown in FIG.  5  and FIG.  6 . 
   FIG.  7 - FIG. 12  are views showing other embodiments of the invention and corresponding to FIG.  4 . 
   In the embodiment shown in  FIG. 7 , single protrusions  34 ,  35  and  36  are provided on the rear portions of the operating portions  33   a ,  33   b  and  33   c , the touch feelings thereof are mutually differentiated. A first protrusion  34  provided on the associated operating portion  33   a  has a cylindrical shape protruding the operating portion  33   a , a second protrusion  35  provided on the operating portion  33   b  has a cylindrical shape with a wide rounded outer face not protruding the operating portion  33   b , and a third protrusion  36  has a cylindrical shape with a small plane outer face in a plane slightly below that the operating portion  33   b  terminates. 
   In the embodiment shown in  FIG. 8 , by differentiating the positions of the protrusions  38 ,  39  and  40  on the operating portions  37   a ,  37   b  and  37   c , the touch feelings are mutually differentiated. Namely a first protrusion  38  is located near the upper axial end of a first one of the operating portions  37   a ,  37   b  and  37   c , a second protrusion  39  at an intermediate location between the axial ends of a second one of the operating portions  37   a ,  37   b  and  37   c , and a third protrusion  40  near a lower axial end of a third one of the operating portions  37   a ,  37   b  and  37   c . Each protrusion  38 ,  39  and  40  can have a shape providing for a flat upper surface and an inclined lower surface. 
   In the embodiment shown in  FIG. 9 , by differentiating shapes of protrusions  42 ,  43  and  44  provided on the operating portions  41   a ,  41   b  and  41   c , the touch feelings are mutually differentiated. Namely one of the protrusions  42 ,  43  and  44  can have a half ball shape, another one of the protrusions  42 ,  43  and  44  a pyramid shape, and yet another one of the protrusions  42 ,  43  and  44  a rectangular shape. 
   In the embodiment shown in  FIG. 10 , by differentiating the shapes, positions and numbers of protrusions  46 ,  47  and  48  provided on, the touch feelings are mutually differentiated. Namely a single roof shaped protrusion  46  is located at a center of one of the operating portions  45   a ,  45   b  and  45   c , a single protrusion  47  having a triangular shape in side view is located near the upper axial end of another one of the operating portions  45   a ,  45   b  and  45   c , and a corrugation pattern comprising a number, e.g. three inclined ridges is at a location intermediate the axial ends of the associated operating portion  45   c.    
   In FIG.  11  and  FIG. 12  further embodiments of the invention are shown in which by differentiating the shapes of protrusions  50 ,  51  and  52 , and  54 ,  55  and  56  provided on the operating portions  49   a ,  49   b  and  49   c , and  53   a ,  53   b  and  53   c , the touch feelings thereof are mutually differentiated. 
   Besides the embodiments explained above, for example, by suitably combining the protrusions shown in FIG.  4 - FIG. 12 , one set of operating portions having mutually different touch feelings may be made. 
   Additionally, even for the protrusions whose shapes, numbers and positions are the same, the touch feelings may be mutually differentiated by differentiating the hardness or haptic properties of the protrusions. 
   According to the invention, since the touch feelings of the operating portions of the reservoir tubes having different writing colors are mutually differentiated, a desired writing color can be easily selected by the finger of hand even in a gloomy place and even by a person with poor eyesight to thereby present it for use. A desired writing color can be easily selected from among many writing colors of a number of ballpoint pens to thereby present a specific one for use. A ballpoint pen or a mechanical pencil which provides the above mentioned advantages can be obtained. 
   The above description of embodiments of the invention has been given by way of example. From the disclosure given, those skilled in the art will not only understand the present invention and the attendant advantages, but will also find apparent various changes and modifications to the structures disclosed. It is sought, therefore, to cover all such changes and modifications as within the spirit and scope of the invention, as defined by the appended claims, and equivalents thereof.