Patent Publication Number: US-2022227164-A1

Title: Retractable element for a writing implement

Description:
1. FIELD OF THE DISCLOSURE 
     This application claims benefit from U.S. provisional patent application U.S. 62/840,759 filed on 30 Apr. 2019 its content being incorporated herein by reference. The present disclosure relates to writing implements having a writing tip and a rubbing element that can rub against markings from the writing tip to erase or change the color thereof. More particularly, the present disclosure relates to a writing implement having a writing tip that extends from a barrel for marking and a rubbing element that surrounds the writing tip that is extendible from a housing to erase or change color of the markings and retractable into the housing for storage. 
    
    
     2. DESCRIPTION OF THE RELATED ART 
     Writing implements have erasers or friction members to erase markings or change color of markings, respectively. Typically, erasers and friction members are attached to a writing implement so that the eraser or friction member is always exposed. Such exposure can lead to damage or accumulation of dirt leading to diminished effectiveness for erasing or changing color of markings. In particular, these friction members and erasers are easily damaged or accumulate dirt when unintentionally contacting other items and surfaces. 
     Accordingly, there is a need to address these disadvantages of currently available writing implements. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure provides a writing implement having a writing tip extending from the barrel for marking, and a rubbing element that surrounds the writing tip and that is selectively extendable from a housing to erase or change color of the marking and retractable into the housing for storage. 
     The present disclosure also provides such a writing implement in which the extension and retraction of the writing tip is independent of the extension and retraction of the rubbing element. 
     The present disclosure further provides such a writing implement in which the extension and retraction of the writing tip is opposite to the extension and retraction of the rubbing element. 
     The present disclosure still further provides such a writing implement in which the extended position of the rubbing element is maintained, specifically by a blocking system. 
     The present disclosure yet further provides such a writing implement in which the rubbing element is maintained in the retracted position, specifically by a blocking system, when the user moves the writing tip to the extended position. 
     The above-described features of the present disclosure will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top, side perspective view of a first embodiment of a writing implement having a writing tip in a stored position and a rubbing element in a retracted position. 
         FIG. 2  is a bottom, side perspective view of the first embodiment of the writing implement of  FIG. 1 . 
         FIG. 3  is an exploded top, side perspective view of the first embodiment of the writing implement of  FIG. 1 . 
         FIG. 4A  is a partial cross-sectional view of the first embodiment of the writing implement of  FIG. 1 . 
         FIG. 4B  is a partial cross-sectional view of the first embodiment of the writing implement of  FIG. 1  having the rubbing element in an extended position. 
         FIG. 4C  is a partial cross-sectional view of the first embodiment of the writing implement of  FIG. 1  modified from  FIG. 4A  to include stoppers. 
         FIG. 5  is a top, side perspective view of a second embodiment of a writing implement having a writing tip in a stored position and a rubbing element in a retracted position. 
         FIG. 6  is a partial top, side perspective view of the second embodiment of the writing implement of  FIG. 5  showing a housing as transparent. 
         FIG. 7  is a top, side perspective view of a third embodiment of a writing implement having a writing tip in a stored position and a rubbing element in a retracted position. 
         FIG. 8  is a bottom, side perspective view of the third embodiment of the writing implement of  FIG. 7 . 
         FIG. 9  is an exploded top, side perspective view of the third embodiment of the writing implement of  FIG. 7 . 
         FIG. 10  is an exploded partial, top, side perspective view of the third embodiment of the writing implement of  FIG. 7  having a receiving portion removed. 
         FIG. 11  is a top, side perspective view of a fourth embodiment of a writing implement having a writing tip in a stored position and a rubbing element in a retracted position. 
         FIG. 12  is a top, front perspective view of the fourth embodiment of  FIG. 11 . 
         FIG. 13  is a partial bottom, side perspective view of the fourth embodiment of the writing implement of  FIG. 11  showing a housing removed. 
         FIG. 14  is a top, side perspective view of a fifth embodiment of a writing implement having a writing tip in a stored position and a rubbing element in a retracted position. 
         FIG. 15  is a partial top, side perspective view of the fifth embodiment of  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     Referring to  FIGS. 1 and 2 , there is provided a writing implement generally represented by reference numeral  100 . Writing implement  100  has a barrel  102 , a writing tip assembly  104  and a rubbing element assembly  200 . Writing implement  100  can also have a clip  106 . 
     Writing implement  100  may have thermochromic ink to write on a substrate such as paper. The thermochromic ink of writing implement  100  has a color that is changed when heat is applied to the markings. Heat is applied to the markings by a rubbing element  204  rubbing the paper so that the friction between the rubbing element  204  and the paper generates heat. In examples, a peelable ink such as inks with two phases, a dye and a resin, may be used. In this type of ink the color can be changed as the dye comes into the paper and the resin gets on to the paper, forming a different layer such that when one erases, the ink is peeled, particularly the resin layer is peeled thus making visible the dye layer which may have a different color. In examples, a combination of a thermochromic ink and a peelable ink may be used. Alternatively, writing implement  100  can have other erasable inks in which rubbing a rubbing element or eraser can erase or change the color of the ink, or writing implement  100  can use pencil lead and rubbing element assembly  200  can extend and retract as an eraser. Rubbing element assembly  200  selectively extends rubbing element  204  to rub the substrate and retracts a rubbing element  204  for storage. It is undesirable for rubbing element  204  to be exposed at all times because such exposure can lead to damage or accumulation of dirt leading to diminished effectiveness for erasing or changing color of markings. 
     Still referring to  FIGS. 1 and 2 , writing tip assembly  104  selectively extends a writing tip  110  for writing and retracts writing tip  110  for storage. Writing tip assembly  104  has a button  108  that moves into and out of barrel  102  through a hole  107  to extend writing tip  110  out of barrel  102  for writing and retract writing tip  110  into barrel  102  for storage. Writing tip assembly  104  selectively extends and retracts writing tip  110  by a click mechanism that is also called a ratchet mechanism or knock mechanism that is known in the art, and, thus, not discussed in detail herein. Writing tip  110  is shown as a ballpoint pen tip. However, writing tip  110  can be any writing tip, for example, a marker nib, mechanical pencil, or other writing tip. 
     Rubbing element assembly  200  has a housing  202  and rubbing element  204 . Housing  202  has a hole  203 . Housing  202  is rotatable relative to barrel  102 , as shown by arrows  206 , to selectively extend rubbing element  204  through hole  203  out of housing  202  and retract rubbing element  204  inside of housing  202 . Rubbing element  204  is a material that changes the color of thermochromic ink when rubbing element  204  rubs the thermochromic ink that is on paper or other substrate, an eraser material that erases pencil marks, or other eraser material that erases erasable inks. A material of rubbing element  204  is, for example, kneading silicone material (e.g. made by Toray Dow Chemical Silicone Co., Ltd., Product Name: DY32-7040U) to which can been added purple pigment (made by Shin-Etsu Chemical, Product Name: KE-Color R2301), 0.09 parts, and red pigment (made by Shin-Etsu Chemical, Product Name: KE-Color X-93-942), 0.13 parts. In general, any TPE (thermoplastic elastomer) materials having a Shore A hardness lower than 100 and that changes the color of thermochromic ink and/or a peelable ink may be used. Examples of such materials for the rubbing element  204  may be thermoplastic polyurethane polyether marketed as DESMOPAN DP 6064 A, 65 Shore A manufactured by COVESTRO. Still other examples of a material of rubbing element  204  may be cork and/or DESMOPAN DP 6084 A, with for example 84 Shore A manufactured by COVESTRO. In circumstances materials having 30-100 Shore A hardness may also be used. Rubbing element  204  may also be a tube forming a passage from opening  205  to opening  207  ( FIG. 3 ). The above examples shall not limit the scope of this disclosure. 
     Referring to  FIG. 3 , writing tip  110  is connected to a cartridge  112  that holds thermochromic ink. Rubbing element assembly  200  has a rubbing element connector  208 . Rubbing element connector  208  has a connecting portion  210 , a protrusion  212  and an extension  213 . Connecting portion  210  has a hole  216 . Protrusion  212  and extension  213  each protrude from connecting portion  210 . Connecting portion  210  connects to rubbing element  204  so that rubbing element  204  is fixed with rubbing element connector  208 . 
     Referring to  FIG. 4A , housing  202  has an exterior surface  218  and an interior surface  220  opposite exterior surface  218 . Exterior surface  218  can be gripped by a user. Interior surface  220  has a groove  222  that is a helix shape. Groove  222  is formed in a tube  224  that connected to interior surface  220  of housing  202 . Alternatively, groove  222  can be formed directly in interior surface  220 . Protrusion  212  fits in groove  222  so that protrusion  212  is movable along groove  222 . Protrusion  212  and connecting portion  210  are sized large enough so that rubbing element connector  208  cannot be removed from groove  222  to maintain a connection between rubbing element connector  208  and housing  202  and also connecting rubbing element  204  to housing  202  by rubbing element connector  208 . Cartridge  112  is positioned through hole  216  and passes into the passage in rubbing element  204 . 
     Barrel  102  has an interior surface  103 . Interior surface  103  has a groove  105 . Groove  105  has a shape and size to allow vertical movement of extension  213  between a first end  109  of groove  105  and a second end  111  of groove  105 . Groove  105  has a shape and size to prevent rotational movement of extension  213  relative to barrel  102 . Rubbing element connector  208  that has protrusion  212  enters in groove  222  to enable movement of rubbing element connector  208  by turning barrel  102  versus rubbing element assembly  200 , then rubbing element connector  208  is keyed/blocked in rotation. In other words, rotation is prevented by barrel  102  so that rubbing element connector  208  can only translate in directions shown by arrows  226  relatively to barrel  102 . Otherwise, rubbing element connector  208  will rotate without translating relatively to barrel  102  and rubbing element  204  will not emit from hole  203 . 
     Alternatively, rubbing element connector  208  can omit extension  213  and barrel  102  can omit groove  105  and hole  216  and cartridge  112  can be sized to prevent rotation between rubbing element connector  208  and cartridge  112  and allow relative movement between rubbing element connector  208  and cartridge  112  along direction  226  along a length of cartridge  112  with rotation prevented by a friction fit of cartridge  112  inside hole  216  of rubbing element connector  208 . Another alternative example, is that the cartridge  112  can have vertical protrusions or grooves that mate with corresponding protrusions or grooves formed inside hole  216  of rubbing element connector  208 . The click mechanism has a spring that urges cartridge  112  toward hole  107  in barrel  102  that is generally located in the nose; however, this is not standard. The spring of the knock mechanism can be located more upward if a crimp/shoulder is located higher on the cartridge. The spring of the click mechanism is positioned above a rubbing element connector  208  of rubbing element assembly  200  so as not to interfere in any way with rubbing element  204 , for example, by placing a shoulder inside of barrel  102  for one end of the spring to abut against and a crimp on cartridge  112  above rubbing element connector  208  for an opposite end of the spring to abut against. 
     In use, to extend a portion of rubbing element  204  outside of housing  202  to an extended position from a retracted position, a user grips housing  202  and rotates housing  202  in a direction as shown by arrow  230 , the user grips barrel  102  rotating barrel  102  in a direction as shown by arrow  228 , or the user grips both housing  202  to rotate housing  202  in the direction as shown by arrow  228  and the user grips barrel  102  to rotate barrel  102  in the direction as shown by arrow  230 , to move protrusion  212  along groove  222  moving rubbing element  204  in a axial direction as shown by arrow  231 . Since extension  213  is in groove  105 , rubbing element connector  208  and rubbing element  204  that is connected to rubbing element  204  do not rotate relative to barrel  102  moving protrusion  212  along groove  222  and extension  213  along groove  105  to move rubbing element connector  208  and rubbing element  204  in direction  231  relative to barrel  102 . Rubbing element connector  208  and rubbing element  204  move in direction  231  relative to barrel  102  until the user stops applying rotation, until a barrier in groove  222  blocks further movement of protrusion  212  in groove  222 , or until extension  213  abuts second end  111  of groove  105 . The barrier in groove  222  that blocks further movement or second end  111  of groove  105  is positioned so that movement of rubbing element  204  is stopped when rubbing element  204  has a desired portion outside of housing  202 . In further examples, as shown in  FIG. 4C , to partially lock the movement of the rubbing element connector  208  and rubbing element  204 , a stopper, e.g., first stopper  234  and a second stopper  236 , in the form of protrusions are able to make a click effect (or snap fit or press fit) that may be located in groove  105  and/or groove  222 . The provision of the stopper allows locking the rubbing element  204  in a deployed and in a retracted position. Thus, no accidental retraction of deployment may occur while in use. The stopper may comprise an inclined portion before the protrusion to serve for an easier use. The user shall apply a little more force in order to lock the rubbing element  204  in the deployed or retracted position. By this the rubbing element  204  becomes safer for use. Protrusion  212  can move along groove  222  until the portion of rubbing element  204  is extended outside of housing  202  as shown in  FIG. 4B . Movement of rubbing element connector  208  and rubbing element  204  is limited by groove  222  preventing movement of protrusion  212  in the direction as shown by arrow  232  so that rubbing element  204  is maintained in the extended position when the user is erasing with rubbing element  204 . This forms a blocking system for withstanding the vertical erasing force when the user is erasing with rubbing element  204 . 
     To retract the portion of rubbing element  204  outside of housing  202  from the extended position, the user can grip: housing  202  and rotates housing  202  in the direction as shown by arrow  228 , or barrel  102  rotating barrel  102  in the direction as shown by arrow  230 , or both housing  202  to rotate housing  202  in the direction as shown by arrow  228  and barrel  102  to rotate barrel  102  in the direction as shown by arrow  230 , to move protrusion  212  along groove  222  moving rubbing element  204  in a direction as shown by arrow  232 . Since extension  213  is in groove  105 , rubbing element connector  208  and rubbing element  204  that is connected to rubbing element  204  do not rotate relative to barrel  102  moving protrusion  212  along groove  222  and extension along groove  105  to move rubbing element connector  208  and rubbing element  204  in direction  232  relative to barrel  102 . Protrusion  212  moves along groove  222  until the user stops applying rotation, until a barrier in groove  222  blocks further movement of protrusion  212  in groove  222 , or until extension  213  abuts first end  109  of groove  105 . The barrier in groove  222  that blocks further movement or first end  109  of groove  105  is positioned so that movement of rubbing element  204  is stopped when rubbing element  204  is completely inside housing  202 . 
     Referring to  FIG. 1 , when the user applies a force to button  108  in a direction as shown by arrow  114  and releases the force when the writing tip  110  is in a stored position, cartridge  112  and writing tip  110  are moved in the direction as shown by arrow  114  to a writing position. Referring back to  FIG. 4A , when button  108  is moved in the direction as shown by arrow  114  in  FIG. 1 , cartridge  112  and writing tip  110  are moved through hole  216  of rubbing element connector  208  and through opening  205  shown in  FIG. 1 , the passage and opening  207  of rubbing element  204  shown in  FIG. 3 . Movement of rubbing element connector  208  and rubbing element  204  is limited by groove  222  preventing movement of protrusion  212  in the direction as shown by arrow  114  so that rubbing element  204  is maintained inside of housing  202  when button  108  is moved in the direction as shown by arrow  114 . When the user applies a force to button  108  in the direction as shown by arrow  114  and releases the force when the writing tip  110  is in the writing position, cartridge  112  and writing tip  110  are moved in a direction opposite to the direction as shown by arrow  114  to the stored position. Again, movement of rubbing element connector  208  and rubbing element  204  is limited by groove  222  preventing movement of protrusion  212  in the direction opposite to the direction as shown by arrow  114  so that rubbing element  204  is maintained inside of housing  202  when button  108  is moved. Accordingly, when user actuates on button  108 , rubbing element  204  does not move. As discussed herein, writing tip assembly  104  selectively extends and retracts writing tip  110  by the knock mechanism. The writing implement can be a top actuation as shown in  FIG. 1 , a side actuation or a stick. 
     Thus, rubbing element  204  is initially disposed inside housing  202 . Rubbing element  204  is operated by rubbing element assembly  200  that is separate from writing tip assembly  104 . Rubbing element  204  will project (and thus retract) from inside of housing  202  and to outside of a front end of housing  202  for use. Movement of rubbing element  204  is similar to a moving sleeve, namely rubbing element  204  and writing tip  110  are concentric with writing tip  110  being disposed inside of rubbing element  204  and writing tip  110  is projected/retracted from inside of rubbing element  204 . Writing tip assembly  104  is disposed at a rear end of barrel  102 . Rubbing element assembly  200  is a portion of the front end of writing implement  100 . The portion of the front end, namely, housing  202 , “twists/rotates” to initiate a projection/retraction movement of rubbing element  204  from inside of housing  202  to the outside of the front end of housing  202  and vice-versa. Accordingly, rubbing element  204  can be selectively stored and exposed for use in writing implement  100  avoiding damage or accumulation of dirt that can lead to diminished effectiveness for erasing or changing color of markings. 
     Referring to  FIG. 5 , a second embodiment of a writing implement  500  that has a writing tip assembly  504  and a rubbing element assembly  600  of the present disclosure is shown. Writing implement  500  has a barrel  502 , writing tip assembly  504  and a rubbing element assembly  600 . Writing implement  500  can also have a clip  506 . Writing tip assembly  504  is the same as writing tip assembly  104 . Accordingly, features that are the same for writing tip assembly  504  and writing tip assembly  104  have the same reference numerals. Writing tip  110  is connected to cartridge  512  that holds thermochromic ink. 
     Referring to  FIG. 6 , rubbing element assembly  600  has a housing  602  and rubbing element  604 . Housing  602  has a hole  603 . Housing  602  is connected to barrel  502 . No rotative movement is necessary between barrel  502  and housing  602  on writing implement  500 , and, thus, both barrel  502  and housing  602  can be fixed together. Housing  602  has side wall  617 . Side wall  617  has an opening  618 . Opening  618  is backward C-shape, C-shape, Z-shape or similar shape, having a top portion  619 , a middle portion  621  and a bottom portion  623 . Rubbing element  604  is the same as rubbing element  204  described herein. Rubbing element assembly  600  has a rubbing element connector  608 . Rubbing element connector  608  has a connecting portion  610  and a protrusion  612 . Connecting portion  610  has a hole  616 . Cartridge  512  is positioned through hole  616  and passes into the passage in rubbing element  604 . Protrusion  612  protrudes from connecting portion  610  through opening  618 . Connecting portion  610  connects to rubbing element  604  so that rubbing element  604  is movable, in a direction as shown by arrow  614 , to selectively extend rubbing element  604  through hole  603  out of housing  602  to an extended position, similar to the extended position of rubbing element  204  shown in  FIG. 4B , and retract rubbing element  604  inside of housing  602  in a retracted position. 
     In use, a user grips protrusion  612  and moves protrusion  612  from top portion  619  of opening  618  to middle portion  621 , and, then, from middle portion  621  to bottom portion  623  of opening  618  to move rubbing element  604  from the retracted position to the extended position. Positioning protrusion  612  in bottom portion  623  of opening  618  prevents movement of protrusion  612  in a direction that is opposite to the direction as shown by arrow  614  so that rubbing element  604  is maintained in the extended position when the user is erasing with rubbing element  604 . This forms a blocking system for withstanding the vertical erasing force when the user is erasing with rubbing element  604 . The user grips protrusion  612  and moves protrusion  612  from bottom portion  623  of opening  618  to middle portion  621 , and, then, from middle portion  621  to top portion  619  of opening  618  to move rubbing element  604  from the extended position to the retracted position. Positioning protrusion  612  in top portion  619  of opening  618  prevents movement of protrusion  612  in the direction as shown by arrow  614  so that rubbing element  604  is maintained in the retracted position when the user moves cartridge  512 . This forms a blocking system for maintaining rubbing element  604  inside of housing  602 . 
     Thus, after protrusion  612  is moved to middle portion  621  of opening  618 , protrusion  612  “slides” or is activated by a “press” action to initiate the projection/retraction movement of rubbing element  604  from inside of housing  602  to the outside of a front end of housing  602  and vice-versa. Rubbing element assembly  600  selectively extends and retracts rubbing element  604  by action on, or a force applied to, protrusion  612  following direction  614  as a simple translation, or rubbing element  604  can be moved by a click mechanism that is also called a knock mechanism that is known in the art, and, thus, not discussed in detail herein. 
     When writing tip  110  is moved to the writing position or the stored position and rubbing element  604  is in the extended position, then rubbing element  604  maintained in the extended position. When writing tip  110  is moved to the writing position or the stored position and rubbing element  604  is in the retracted position, then rubbing element  604  maintained in the retracted position. When rubbing element  604  is moved to the extended position or the retracted position and writing tip  110  is in the stored position, then writing tip  110  maintained in the stored position. When rubbing element  604  is moved to the extended position or the retracted position and writing tip  110  is in the writing position, then writing tip  110  maintained in the writing position. To achieve the foregoing, protrusion  612  that is attached to rubbing element  604  is “locked” into top portion  619  to maintain rubbing element  604  in the retracted position or bottom portion  623  to maintain rubbing element  604  in the extended position, and cartridge  512  is “locked” in extended or retracted position by the knock mechanism that is under button  108  that is attached to cartridge  512 . To summarize, cartridge  512  and rubbing element  604  have two “locked” positions that are independent from each, due to two special shaped mechanisms. Thus, the extended position and retracted position of cartridge  512  and rubbing element  604  are independent or opposite to each other. If rubbing element  604  extends at the same time as cartridge  512 , then rubbing element  604  must have an offset compared with the pen tip of cartridge  512 , otherwise, the user will rub at the same time he or she writes. Accordingly, rubbing element  604  can be selectively stored and exposed for use in writing implement  500  avoiding damage or accumulation of dirt that can lead to diminished effectiveness for erasing or changing color of markings. 
     Thus, rubbing element  604  is operated by rubbing element assembly  600  that is separate from writing tip assembly  504 . Writing tip assembly  504  is disposed at a rear end of barrel  502  and can be operated by click operation. Rubbing element  604  is projected/retracted from inside of housing  602  and moved to the outside of housing  602  at the front end of housing  602  for use. Movement of rubbing element  604  is similar to a moving sleeve, wherein the rubbing element  604  and writing tip  510  are concentric with writing tip  510  being disposed inside of rubbing element  604  and is projected/retracted from inside of rubbing element  604 . Protrusion  612  is located on an outer surface of housing  602  and can extend radially from the outside surface of housing  602  or may not extend radially from the outside surface. Rubbing element assembly  600  “slides” or is activated by a “press” action to initiate the projection/retraction movement of rubbing element  604  from inside of housing  602  to the outside of the front end of housing  602  and vice-versa. 
     Referring to  FIGS. 7 and 8 , a third embodiment of a writing implement  700  of the present disclosure is shown. Writing implement  700  has a writing tip assembly  704 , a barrel  705  and a rubbing element assembly  800 . Writing implement  700  can also have a clip  706 . Barrel  705  has side wall  717 . Side wall  717  has an opening  718 . Opening  718  is C-shape, backward C-shape, Z-shape or similar shape, having a top portion  719 , a middle portion  721  and a bottom portion  723 . Rubbing element assembly  800  has a rubbing element  804  and a protrusion  812  that is accessible through opening  718 . Writing tip assembly  704  has a housing  702 . Housing  702  has a hole  703 . Housing  702  is rotatable relative to barrel  705 , as shown by arrows  706 , to selectively extend writing tip  710 , shown in  FIG. 9 , through hole  703  out of housing  702  and retract writing tip  710  inside of housing  702 . 
     Referring to  FIGS. 9 and 10 , protrusion  812  is connected to a bridge  842 . When assembled, land  844  is connected to bridge  842 . Rubbing element  804  is connected to land  844 . 
     Referring in particular to  FIG. 9 , writing tip  710  is connected to a cartridge  712  that holds thermochromic ink. Cartridge  712  passes through in a hole  746  in a ring  748  so that cartridge  712  is fixed with ring  748  because ring  748  is the element that enables cartridge  712  to actuate from the retracted position to the extended position and vice versa. Ring  748  has a receiving portion  750 , a projection  752  and an extension  753 . Barrel  705  has an interior surface that has a groove similar to groove  105  of  FIG. 4  described herein. The groove in the interior surface of barrel  705  has a shape and size to allow vertical movement of extension  753  between a first end of the groove and a second end of the groove. The groove has a shape and size to prevent rotational movement of extension  753  relative to barrel  705 . Cartridge  712  passes through an opening  846  in land  844  into a passage in rubbing element  804 . Rubbing element  804  is the same as rubbing element  204  described herein. Cartridge  712 , opening  846  and rubbing element  804  are sized so that cartridge  712  can move in opening  846  and rubbing element  804  without modifying positions of opening  846  and rubbing element  804 . Projection  752  is inside a thread  754  in a band  756 . Ring  748  is sized so that ring  748  fits in band  756 . Bridge  842  can either be between receiving portion  750  and band  756  or outside of band  756  so that band  756  accommodates rotational movement of band  756 , bridge  842 , or band  756  and bridge  842  relative to one another. Bridge  842  can have a convex shape to abut a portion of band  756  so that bridge  842  guides movement of ring  748  in the direction shown by arrow  814  and in a direction opposite the direction shown by arrow  814 . Band  756  is connected inside of housing  702 . An alternative that is not shown replaces band  756  with opening through housing  702  that has a helix shape similar to opening  1177  described herein. 
     In use, when rubbing element  804  is in a stored position, a force applied to protrusion  812  moves protrusion  812  from top portion  719  of opening  718  to middle portion  721 , and, then, from middle portion  721  to bottom portion  723  of opening  718  to move rubbing element  804  from the retracted position to the extended position, similar to the extended position of rubbing element  204  shown in  FIG. 4B , outside of housing  702 . Positioning protrusion  812  in bottom portion  823  of opening  818  prevents movement of protrusion  812  in a direction that is opposite to the direction as shown by arrow  814  so that rubbing element  804  is maintained in the extended position when the user is erasing with rubbing element  804 . This forms a blocking system for withstanding the vertical erasing force when the user is erasing with rubbing element  804 . The user grips protrusion  812  and moves protrusion  812  from bottom portion  723  of opening  718  to middle portion  721 , and, then, from middle portion  721  to top portion  719  of opening  718  to move rubbing element  804  from the extended position to the retracted position. Positioning protrusion  812  in top portion  719  of opening  718  prevents movement of protrusion  812  in the direction as shown by arrow  814  so that rubbing element  804  is maintained in the retracted position when the user moves cartridge  712 . This forms a blocking system for maintaining rubbing element  804  inside of housing  702 . 
     After protrusion  812  is moved to middle portion  721  of opening  718 , bridge  842  selectively extends and retracts rubbing element  804  by protrusion  812  that “slides” or is activated by a “press” action to initiate the projection/retraction movement of rubbing element  804  from inside of housing  702  to the outside of a front end of housing  702  and vice-versa. Rubbing element assembly  800  selectively extends and retracts rubbing element  804  by action on, or a force applied to, protrusion  812  following direction  814  as a simple translation. Accordingly, rubbing element  804  can be selectively stored and exposed for use in writing implement  800  avoiding damage or accumulation of dirt that can lead to diminished effectiveness for erasing or changing color of markings. 
     To extend writing tip  710  from a stored position, a user grips barrel  705  and housing  702  and rotates one of or both of housing  702  in a direction as shown by arrow  764  and barrel  705  in a direction as shown by arrow  766  so that projection  752  rotates along thread  754  moving writing tip  710  in the direction as shown by arrow  814  out of hole  703  to be outside of housing  702  to a writing position. Since extension  753  is in the groove in the interior surface of barrel  705 , ring  748  and cartridge  712  that is connected to ring  748  do not rotate relative to barrel  705  moving protrusion  752  along thread  754  and extension  753  along the groove in the interior surface of barrel  705  to move extension  753  and writing tip  710  in direction  814  relative to barrel  705 . To retract writing tip  710  from the writing position, the user grips barrel  705  and housing  702  and rotates one of or both of housing  702  in a direction as shown by arrow  766  and barrel  705  in a direction as shown by arrow  764  so that projection  752  rotates along thread  754  moving writing tip  710  in the direction opposite to the direction as shown by arrow  814  to be inside of housing  702  to the stored position. Since extension  753  is in the groove in the interior surface of barrel  705 , ring  748  and cartridge  712  that is connected to ring  748  do not rotate relative to barrel  705  moving protrusion  752  along thread  754  and extension  753  along the groove in the interior surface of barrel  705  to move extension  753  and writing tip  710  in direction opposite direction  814  relative to barrel  705 . When user rotates housing  702 , writing tip  710  is extended or retracted depending on the direction of the rotation, e.g., direction of arrow  764  or direction of arrow  766  and writing tip  710  is retracted by the rotation of housing  702 , therefore, bridge  842  and cartridge  712  are independent from one other. 
     Thus, rubbing element  804  is disposed inside housing  702 . Rubbing element  804  is operated by rubbing element assembly  800 . Rubbing element assembly  800  can be protrusion  812  or a clip located at a rear end of barrel  705 . Rubbing element assembly  800  is separate from writing tip assembly  704 . Writing tip assembly  704  is disposed at a front end of barrel  705 . Writing tip assembly  704  is a portion of a front end of barrel  705 , namely the portion of the front end of barrel  705  “twists/rotates” to initiate a projection/retraction movement of writing tip  710  from inside of rubbing element  804  to the outside of the front end of housing  702  and vice-versa. To summarize, rubbing element  804 , bridge  842 , land  844  and protrusion  812  are moved by a translation movement in the direction shown by arrow  814  and opposite the direction shown by arrow  814  between the retracted position and the extended position. Writing tip  710 , cartridge  712  and ring  748  are moved between the retracted position and the extended position by a twisting mechanism including band  756 . To enable the translation of writing tip  710 , ring  748  should be keyed by extension  753  positioned in the groove in the interior surface of barrel  705  so that ring  748  can only translate in the direction shown by arrow  814  and opposite the direction shown by arrow  814  relative to barrel  705  and rotation of ring  748  relative to barrel  705  is prevented. 
     Rubbing element  804  is projected/retracted from inside of housing  702  and moved to an outside of housing  702  by a “slide” action, for example, by a clip linked with protrusion  812  or bridge  842  or similar structure located at the rear end of barrel  705 . Movement of rubbing element  804  would be similar to a moving sleeve, namely rubbing element  804  and writing tip  710  are concentric with writing tip  710  being disposed inside of rubbing element  804  and is projected/retracted from inside of rubbing element  804 . Accordingly, rubbing element  804  can be selectively stored and exposed for use in writing implement  700  avoiding damage or accumulation of dirt that can lead to diminished effectiveness for erasing or changing color of markings. 
     Referring to  FIGS. 11-13 , a fourth embodiment of a writing implement  1100  that has a barrel  1102 , a writing tip assembly  1104  and a rubbing element assembly  1200  of the present disclosure is shown. 
     Referring again to  FIG. 13 , barrel  1102  is the same as barrel  705  except barrel  1102  has opening  1101  at barrel end  1105  instead of opening  718  in side wall  717  and barrel  1102  does not include the groove on the interior surface of barrel  705 . Rubbing element assembly  1200  is the same as rubbing element assembly  800  except rubbing element assembly  1200  has bridge  842  connected to button  1212  through opening  1101  instead of protrusion  812  so that rubbing element  804  is moved up and down by a pressure on button  1212  via a click/knock/ratchet system located in the top of barrel  1102  instead of movement of protrusion  812  in opening  718 . Accordingly, features that are the same for rubbing element assembly  1200  and rubbing element assembly  800  have the same reference numerals. Writing tip assembly  1104  has the same cartridge  712  and writing tip  710  as writing tip assembly  704 , and, accordingly, the same reference numerals are used for cartridge  712  and writing tip  710  of writing tip assembly  1104 . Writing tip assembly  1104  has ring  749  instead of ring  748 . Ring  749  has protrusion  752 ; however, ring  749  does not include extension  753 . Cartridge  712  and ring  749  are not connected to and are free of barrel  1102 . Cartridge  712  passes through hole  747  in a body  751  of ring  749  so that ring  749  and cartridge  712  are fixed with each other. Rotation and translation of cartridge  712  relative to ring  749  is prevented so when protrusion  752  extending from ring  749  travels in opening  1177 , cartridge  712  moves downward or upward. Ring  749  can abut bridge  842  so that movement of ring  749  and cartridge  712  is guided by bridge  842  in a direction as shown by arrow  1114  and in a direction opposite to the direction as shown by arrow  1114 . Cartridge  712  passes through opening  846  in land  844  into the passage in rubbing element  804 . Cartridge  712 , opening  846  and rubbing element  804  are sized so that cartridge  712  can move in opening  846  and rubbing element  804  without modifying positions of each of opening  846  and rubbing element  804  and movements of cartridge  712  and rubbing element  804  are independent. Projection  752  is positioned inside opening  1177  in housing  1180 . Housing  1180  is connected to barrel  1102  so that barrel  1102  and housing  1180  are in a fixed position relative to one another. Opening  1177  is sized so that projection  752  can rotate from a first side  868  of bridge  842  to a second side  870  of bridge  842  a distance along opening  1177  that is long enough to extend writing tip  710  to the writing position. 
     In use, to extend writing tip  710  from a stored position, a user grips projection  752  and housing  1180  or barrel  1102  and rotates one of or both of projection  752  in a direction as shown by arrow  1182  and housing  1180  or barrel  1102  in a direction as shown by arrow  1184  so that projection  752  rotates along opening  1177  moving writing tip  710  in the direction as shown by arrow  1114  out of hole  1103  to be outside of housing  1180  to a writing position. To retract writing tip  710  from the writing position, the user grips projection  752  and housing  1180  or barrel  1102  and rotates one of or both of projection  752  in the direction as shown by arrow  1184  and housing  1180  or barrel  1102  in the direction as shown by arrow  1182  so that projection  752  rotates along opening  1177  moving writing tip  710  in a direction opposite the direction as shown by arrow  1114  to be inside of housing  1180  to the stored. 
     Rubbing element  804  is disposed inside housing  1180 . Rubbing element  804  is operated by a rubbing element assembly  1200 . Rubbing element assembly  1200  is located on an outer surface of barrel  1102  and can extend axially relatively to the barrel  1102 . Rubbing element assembly  1200  is activated by a “press” action to initiate the projection/retraction movement of the rubbing element  804  from inside of housing  1180  to the outside of the front end of housing  1180  and vice-versa. Rubbing element assembly  1200  is separate from writing tip assembly  1104 . Writing tip assembly  1104  is disposed at the front end of housing  1180 . Writing tip assembly  1104  has a portion of a front end of writing implement  1100 , namely housing  1180 , or protrusion  752  that “twists/rotates” to initiate a projection/retraction movement of writing tip  710  from inside of rubbing element  804  to an outside of housing  1180  and vice-versa. Rubbing element  804  is projected/retracted from inside housing  1180  and moved to the outside of housing  1180  by pressing on button  1212  located at the rear end of barrel  1102 . Movement of rubbing element  804  would be similar to a moving sleeve, namely rubbing element  804  and writing tip  710  are concentric and writing tip  710  is disposed inside of rubbing element  804  and is projected/retracted from inside of rubbing element  804 . Accordingly, rubbing element  804  can be selectively stored and exposed for use in writing implement  1100  avoiding damage or accumulation of dirt that can lead to diminished effectiveness for erasing or changing color of markings. 
     Referring to  FIGS. 14 and 15 , a fifth embodiment of a writing implement  1400  of the present disclosure. Writing implement  1400  has a barrel  1402 , a writing tip assembly  1404  and a rubbing element assembly  1500  of the present disclosure is shown. Rubbing element assembly  1500  is the same as rubbing element assembly  200  except rubbing element assembly  1500  has an opening  1577  in barrel  1402  instead of a thread  222  in housing  202  and does not include extension  213  and groove  102 . Writing tip assembly  1404  is the same as writing tip assembly  104 . Opening  1577  is in the shape of a helix. Accordingly, features that are the same for writing implement  1400  and writing implement  100  have the same reference numerals. In use, to move rubbing element  204  from the retracted position to the extended position, a user grasps barrel  1402  and protrusion  212  and rotates one or both of barrel  1402  in the direction as shown by arrow  228  and protrusion  212  in the direction as shown by arrow  230  to move rubbing element  204  to the extended position. To move rubbing element  204  from the extended position to the retracted position, a user grasps barrel  1402  and protrusion  212  and rotates one or both of barrel  1402  in the direction as shown by arrow  228  and protrusion  212  in the direction as shown by arrow  230  to move rubbing element  204  to the retracted position. 
     Accordingly, rubbing elements  204 ,  604 ,  804  can be stored when not in use so that rubbing elements  204 ,  604 ,  804  are not exposed at all times. Thus, exposure that can lead to damage or accumulation of dirt leading to diminished effectiveness for erasing or changing color of markings of rubbing elements  204 ,  604 ,  804  is minimized. Rubbing element  204 ,  604 ,  804  also does not contact any surface of barrels  102 ,  502 ,  705 ,  1102 ,  1402  or housings  202 ,  602 ,  704 ,  1180  during extending and retracting. This prevents damage or soiling of rubbing elements  204 ,  604 ,  804  as well. Rubbing elements  204 ,  604 ,  804  extend past writing tips when both are in extended positions in writing implements  100 ,  500 ,  700 ,  1100 ,  1400  so as to prevent accidental markings by the writing tips. 
     The present disclosure having been thus described with particular reference to some examples or embodiments thereof, it will be understood by those skilled in the art that other alternatives and obvious modifications and equivalents thereof are possible. Furthermore, the present disclosure covers all possible combinations of the particular embodiments described. Thus, the scope of the present disclosure should not be limited by the particular embodiments, but should be determined only by a fair reading of the appended claims. 
     It should be noted that the terms “first”, “second”, “third”, “fourth”, and the like may be used herein to modify various elements. These modifiers do not imply a spatial, sequential, or hierarchical order to the modified elements unless specifically stated. 
     While the present disclosure has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the disclosure without departing from the scope thereof. Therefore, it is intended that the present disclosure will not be limited to the particular embodiment(s) disclosed as the best mode contemplated, but that the disclosure will include all embodiments falling within the scope of the appended claims.