Abstract:
The present invention is a collapsible retractable pen for attachment to a hand-held device, such as a cell phone. The pen extends from a compact size to an extended size to provide a comfortable fit in the hand. The extension exposes, in a coordinating movement, the writing point of a retracted ink refill. The movements are governed by a system of keys and keyways between the telescoping housing components. The nested keys and keyways allow a narrow profile while providing an intuitive operational sequence. The invention includes a sheath, or alternatively a clip, for holding the pen and attaching it an object.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims U.S. Provisional Application No. 60/999,646, filed on Nov. 28, 2007, as a priority application. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to writing instruments and more particularly to pens attachable to a hand-held device, such as a cell phone. 
       BACKGROUND OF THE INVENTION 
       [0003]    There are instances, such as when talking on the phone or watching TV, where a need arises to jot down information. Typically, this involves searching for an instrument to write with and sometime to write on. The latter is usually accessible in such instances. One may find a scrap of paper, a margin of a book or newspaper, a napkin, or a sales receipt stored in a wallet or purse, for example, within easy reach. 
         [0004]    The complementary writing instrument, on the other hand, although a ubiquitous item in most household environments, never seems to be conveniently located. This is particularly true when the instance occurs while moving about with a mobile personal device, such as a cell phone. A pen, for example, attachable to an object often found in one&#39;s hand, such as a cell phone, PDA, pocket calculator, TV remote, makeup case, or even a checkbook, would be a useful implement when the need for note-jotting arises. 
         [0005]    Standard-sized pens, however, typically with a length of six inches or more, and are too bulky for such applications. A size of about half that length would be optimal for fitting within the profile of most mobile electronic devices. 
         [0006]    U.S. Pat. No. 6,409,404 to Piech discloses a pen of such a length in a sheath attachable to a phone with an adhesive strip. Piech&#39;s pen, however, while small in size, is also inconvenient in practice. The short length does not bridge the gap between the fingertips holding the pen and the usual bracing position against the thumb-index finger crotch. Also, the pen in this instance is itself the naked refill cartridge, which lacks sufficient body and stiffness for a customary “hand feel”. What is needed is a grippable barrel that can be extended to a comfortable cradling position in the hand. 
         [0007]    U.S. Design Pat. D438,564 to Green illustrates what appears to be a telescopically collapsible pen in a holder attached to a cell phone. While the telescoping mechanism would conceptually provide extension sufficient for a holding position as described above, it appears that the tip end of the pen remains exposed. This not only provides the potential for the ink to dry out, but also presents the hazard of accidentally marking something. A desirable improvement would be for the tip of the pen to retract within the pen housing for protection during the collapse of the structure, and extend for use simultaneously with the extension thereof. 
         [0008]    Such a means for bilateral collapse and extension is provided in one embodiment by U.S. Pat. No. 6,273,627 to Mittersinker. Mittersinker teaches that a cam postured laterally inside a pen casing is turned to a longitudinal posture, thereby camming a refill cartridge outwardly by the sliding extension of a casing component. Because the lateral posture of the cam must comprehend the length of an arm of the cam providing the extension distance, the body of the casing must be necessarily bulky in girth. Such a bulk would be incompatible with the size of a cell phone, for example. 
         [0009]    A collapsible and retractable pen, which is, at once, sufficiently small in both breadth and length to fit on a cell phone as other than an unwieldy appendage thereto, and sufficiently expandable as to provide a comfortable and pleasingly substantial feel in the hand of a user, is absent in the prior art. 
       SUMMARY OF THE INVENTION 
       [0010]    In view of the above-mentioned unfulfilled needs, the present invention embodies, but is not limited by, the following objects and advantages: 
         [0011]    A first object of the invention is to provide a readily-accessible ball point pen having a refill in a barrel to accompany a hand-held device, such as a cell phone. 
         [0012]    A second object of the invention is to provide a means for collapsing the barrel structure to a length of substantially three inches or less. 
         [0013]    A third object of the invention is to provide a means for retracting the pen refill into the protection of the barrel. 
         [0014]    A fourth object of the invention is to provide a means for extending the pen to a comfortable gripping length while also extending the refill from within the barrel. 
         [0015]    A fourth object of the invention is to maintain a girth dimension of a half inch or less. 
         [0016]    A fifth object of the invention is to provide a means to assemble and disassemble the pen barrel to provide access to the refill for replacement purposes while, at the same time, preventing inadvertent disassembly. 
         [0017]    A sixth object of the invention is to provide an operating means for all functionalities which is essentially “goof-proof”. 
         [0018]    A seventh object of the invention is to provide a means for attaching a collapsible and retractable pen to a hand-held device, such as a cell phone. 
         [0019]    In a preferred embodiment, the pen of the present invention is comprised of two telescoping, essentially tubular, components. The first tubular component, the barrel, houses a ballpoint ink refill with a coaxially disposed spring. The spring biases the refill from a base on the barrel to a retracted position within. The second tubular component, the plunger, essentially surrounds the refill and spring and travels on a parallel axis from a collapsed to an extended position by sliding within the barrel. 
         [0020]    The travel of the plunger is restricted by a plurality of keys and keyways. The keyways, positioned in the inner wall of the barrel, have both longitudinal and transverse extent. The longitudinal, or translational, keyways permit the telescoping of the plunger with respect to the barrel, and the transverse, or rotational, keyways move the barrel and plunger into an interlocking position relative to one another. One particular set of rotational keyways moves the plunger eccentrically with respect to the barrel, thereby shifting the lateral position of the plunger with respect to the refill. One particular translational keyway separates the barrel and plunger for servicing of the ink refill. 
         [0021]    The plunger is provided with a pair of keys, essentially oppositely disposed on the outer surface thereof, which ride in the keyways and traverse the barrel in a manner proscribed by the layout of the paths. The two keys are different is size so that the travel is further limited by a match of key and path. In fact, the system provides only one degree of freedom at each juncture of travel and, in so doing, eliminates any possibility of making a mistake. 
         [0022]    The plunger is also provided with a pawl on the inner surface thereof. The pawl functions to engage the top of the refill when the axis of eccentricity of the plunger is shifted to a position overlapping the refill. The plunger is thus enabled to extend the refill by a short plunging stroke. 
         [0023]    Locking positions are provided in the key and keyway system, both at the end of the plunging stroke and at the fully collapsed position, to secure the operating and storage configurations. A disassembly position is also provided by the key and keyway system. In this case, a purposeful maneuver of the components is required to avoid unintentional separation. 
         [0024]    Another aspect of the preferred embodiment is the provision of a sheath to house the collapsible retractable pen. One side of the sheath is flat to provide a surface for attaching an adhesive means, such as double-faced tape, to bond the sheath to the hand-held device. 
         [0025]    In an alternate embodiment, a clip is provided to hold the collapsible retractable pen in place of the sheath. The clip also has a flat surface for adhesively attaching the pen to a hand-held device of choice. 
         [0026]    The method of using the preferred embodiment begins with the collapsed and retracted position and ends with the fully extended position. The method of collapsing is the reverse procedure. The extension procedure includes the steps: Turning the plunger counterclockwise until stopped to unlock; pulling the plunger up until stopped to extend; turning the plunger counterclockwise again until stopped to cam the barrel to an eccentric position with the pawl extending over the top of the ink refill; pushing the plunger and ink refill down until stopped to compress the spring and expose the writing point; and turning the plunger clockwise until stopped to lock the new configuration. In the collapsing procedure, the retraction of the ink refill becomes facilitated by the spring. 
         [0027]    The method of disassembling the plunger from the barrel to change the refill includes the steps: Turning the plunger counterclockwise until stopped to unlock; pulling the plunger up until stopped to extend; pushing the plunger back down with a slight clockwise twisting pressure until the plunger slips clockwise until stopped; and lifting the plunger free from the outer barrel. The assembly steps are essentially the reverse procedure. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0028]    Various other objects, features and attendant advantages of the present invention will become fully appreciated as the same becomes better understood through the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein: 
           [0029]      FIG. 1  is a perspective view of the collapsible retractable pen in a collapsed position; 
           [0030]      FIG. 2  is a perspective view of the collapsible retractable pen in an extended position; 
           [0031]      FIG. 3  is an exploded view in perspective of the components of the collapsible retractable pen; 
           [0032]      FIG. 4  is a perspective view of the barrel from the top showing one of the two camming keyways; 
           [0033]      FIG. 5  is a perspective view of the barrel from the top at a different angle to show the other camming keyway; 
           [0034]      FIG. 6  is a perspective sectional view along C-C of  FIG. 5 ; 
           [0035]      FIG. 7  is a sectional view along A-A of  FIG. 1  showing the components in a collapsed position; 
           [0036]      FIG. 8  is a sectional view along B-B of  FIG. 2  showing the components in an extended position; 
           [0037]      FIG. 9  is a perspective view of the plunger showing the dissimilar keys; 
           [0038]      FIG. 10  is a perspective view of the plunger from the bottom showing the pawl; 
           [0039]      FIG. 11  is a perspective view of the collapsible retractable pen inserted in the sheath; 
           [0040]      FIG. 12  is a perspective view of the collapsible retractable pen held in the clip. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0041]    The collapsible retractable pen of the present invention, hereinafter pen  10 , is shown in a collapsed configuration in  FIG. 1  and in an extended configuration in  FIG. 2 . The various components of pen  10  are shown in the exploded view of  FIG. 3 . By way of assembly, ink refill  40  is inserted into spring  50  and the refill-spring sub-assembly is inserted into barrel  20 . Plunger  30  is inserted over ink refill  40  and spring  50  within barrel  20  such that the refill-spring sub-assembly resides within the plunger. The ink refill is lidded with refill cap  60  and the plunger with plunger cap  70 . The completed assembly is best shown in the sectional view of  FIG. 8 . 
         [0042]      FIGS. 4-6  further illustrate barrel  20 . Barrel  20  is essentially a tubular housing having a length not exceeding three inches and girth not exceeding one-half inch. It is of unitary construction, preferably molded. Barrel  20  necks to a narrowed orifice  23  at its proximal end  25 . The distal end  26  of barrel  20  is essentially open. Barrel  20  additionally has a network of keyways  200  (the keyways will be discussed in a following passage) recessed in the inner wall thereof. 
         [0043]    Referring to  FIG. 6 , spring  50  ( FIG. 3 ) is inserted into spring recess  21  in the barrel and is supported thereon by spring ledge  22 . Spring recess  21  holds the spring in coaxial alignment with the barrel. Spring  50  is of the steel-coil type commonly used with ballpoint pens. One or more spring lugs  42  on ink refill  40  ( FIG. 3 ) rests on the top of spring  50  in assembly. The length of spring  50  and the location of spring lugs  42  are such that writing point  41  of the ink refill is retracted within barrel  20  when the spring is relaxed. The spring holds the ink refill in coaxially alignment. 
         [0044]    Ink refill  40  is of the common ballpoint pen type found at many merchandisers and, particularly, at office supply stores. Refills of this type are available as replacement ink supplies and are essentially generic in form. Ink refill  40  is customized by cutting the ink reservoir to a preferred size, nominally two and half inches. Because the ink reservoir is generally comprised of plastic tubing, this is easily done with a pair of scissors. The lugs  42 , which typically are formed by pinching the tubing, are standard issue. Refill cap  60  is frictionally fit over the cut end of ink refill  40  to prevent leakage of the ink. Refill cap  60  also functions to provide a dimensionally consistent shape for interaction with the plunger. 
         [0045]      FIGS. 9 and 10  further illustrate plunger  30 . Plunger  30  is essentially tubular in form and of unitary construction, preferably molded. A pair of keys  31  extends radially outward from the outside surface of plunger  30  at or near the proximal end  35  thereof. The extension of keys  31  is substantially equal to the depth of keyways  200 , within which keys  31  are slidingly interposed when assembled thereto. Plunger  30  also has pawl  34  extending radially inward by an equivalent distance from the inside surface of plunger  30 . The pawl  34  has an outside surface  38  which defines a free space inside plunger  30  substantially equivalent to the diameter of spring  50 . The pawl  34  additionally has a proximal end  37  located so as to be at the level of the retracted refill cap top surface  61  when the plunger is fully extended from the barrel, as best shown in  FIG. 8 . 
         [0046]    Plunger  30  is additionally provided with plunger cap  70  fitted to plunger distal end  36 . Plunger cap  70  serves the cosmetic purpose of closing the open end and serves the functional purpose of providing a means for gripping and manipulating the plunger. Plunger cap  70  is preferably adhesively attached to plunger  30 , but such methods as screw-threading, welding, or other known techniques for attaching, are alternatives. 
         [0047]    The keys  31  are of dissimilar shape and size. Key  32  is tall and narrow while key  33  is short and wide. These features match similarly shaped and dimensioned keyways  200 . The short and wide features prevent the assembly of, and relative movement between, the plunger and the barrel in any other than a proscribed way. It is useful for at least one of the keys to be tall, in order to reduce wobble of the plunger when extended, and for the other to be short, so as to permit a short stroke distance. Keys  32  and  33  are positioned oppositely on a diameter that is collinear with pawl  34 . Except as noted in the discussion of camming below, only one of keys  31  will be in interposition with keyways  200  at any one time, the other of keys  31  being positioned at the inner wall surface of barrel  20 . This gives rise to an eccentric posture of plunger  30  with respect to barrel  20 , such that the axis of the plunger is offset from the axis of the barrel on the diameter of co-linearity, on which the keys and the pawl are aligned, by a distance equivalent to a keyway depth.  FIG. 8  illustrates the eccentric posture while  FIG. 7  shows a non-eccentric perpendicular view. 
         [0048]    The movement of the plunger within the barrel is governed by the keys interacting in the keyways along proscribed routes, or paths. Returning to  FIGS. 4-6 , keyways  200  are divided into translational keyways  210  and rotational keyways  220 . Translational keyways  210  provide the means for moving plunger  30  in and out of barrel  20 . Rotational keyways  220  provide, in a counterclockwise sense, the means for shifting the eccentricity of plunger  30  with respect to barrel  20 , or, in a clockwise sense, the means for locking the plunger  30  in place with respect to barrel  20 . The purpose for the eccentricity shift is to move the pawl  34  into position over the refill  49  so that the plunger is in place to urge the refill downwardly in a motion exposing the writing point  41  through the orifice  23 . 
         [0049]    Accordingly, there are camming keyways  221  and locking keyways  222 . Tall camming keyway  223 , best shown in  FIG. 5 , accepts tall narrow key  32  and moves it in rotational progression through continuously diminishing depth to the inner wall surface of the barrel. At the same time, diametrically-opposite short camming keyway  224 , best shown in  FIG. 4 , receives short wide key  33  and moves it simultaneously from the wall surface into continuously increasing depth. This counterclockwise camming rotation shifts the eccentricity of the members and places the pawl proximal end  37 , previously free of interference for travel, over the refill cap top surface  61 . From this position, short wide key  33  can be translated a short distance downward by means of wide keyway  212 , best shown in  FIG. 4 , and into a locking position in upper locking keyway  225  by performing a clockwise twist, best shown in  FIG. 8 . 
         [0050]    Plunger proximal end  35  is assembled to barrel distal end  26  by threading the tall narrow key  32  into exit keyway  211 . Exit keyway  211  is offset from narrow keyway  213 . Narrow keyway  213  routes the plunger for extension by translating it up and down. The purpose of the offset is to prevent accidental disassembly. Exit keyway  211  communicates with narrow keyway  213  by means of connecting keyway  227 . Connecting keyway  227  can only be accessed by applying a clockwise twisting pressure while forcing the plunger up or down. Otherwise, tall narrow key  32  bypasses connecting keyway  227  and continues on to the extended position defined by the upper end of narrow keyway  213 . The collapsed position is achieved by pushing the plunger downward with tall narrow key  32  riding in narrow keyway  213  until plunger  30  is seated against plunger ledge  24 . From that position, tall narrow key  32  can be rotated to a locked position by performing a clockwise twist into lower locking keyway  226 . 
         [0051]    With the exception of exit keyway  211 , which is open to the top, there are abutting sidewalls at all junctures between translational keyways  210  and rotational keyways  220  and at the end of locking keyways  222 . Thus it can be seen that each path has an abutment stop and only option for continuing on at each stop. In this manner, the network of keys and keyways prevents wrong-way operation while avoiding reliance upon operating instructions. 
         [0052]    Referring to  FIGS. 11 and 12 , pen  10  is shown with two means for attachment to a hand-held device, such as a cell phone. Sheath  80  provides a housing into which pen  10  can be inserted and held therein with frictional fit. Venting air during insertion can escape through a hole in the bottom (not shown), or by a polygonal shape, as shown in  FIG. 14 , where the vertices provide interstitial spaces. Sheath  80  has at least one flat side  81  to support a means to adhesively secure the sheath to a host object, such means including double-faced tape, adhesively-backed hook-and-loop fasteners, or any other known means for attachment. In an alternative embodiment, shown in  FIG. 15 , clip  90  is provided for an attachable holder. Clip  90  also has a flat side  91  to support an adhesive means. 
         [0053]    In a preferred embodiment, the barrel  20 , plunger  30 , refill cap  60  and plunger cap  70  are injection molded with thermoplastic materials. The material of choice would have a degree of toughness in addition to hardness for durability. Polypropylene and impact polystyrene are readily available and economical choices having these properties, but numerous other resins would be suitable, including polyolefins and recycled blends. The barrel could be molded in two halves in a family mold and subsequently joined post-molding by such means as ultrasonic welding. Alternatively, it could be molded in a traditional identical-cavity mold with a collapsible core. The other components would present little challenge to moldability. 
         [0054]    It is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the above description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and a carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of the description and should not be regarded as limiting.