Abstract:
Modular fountain pens useable with inks of varying viscosities that utilize a nib with exterior grooves for conveying ink, which removably fits into a coupler that places the nib in fluid communication with a reservoir by way of a central ink tube. The coupler removably secures into a housing, which is closed on its opposite end by a rotating end cap designed to engage the ink reservoir so as to allow the pen user to adjust the internal volume of the reservoir. The pen allows for quick assembly and disassembly, which allows the pen to be easily cleaned between uses to accommodate fluid inks that may leave heavy residues and also allows for the appearance of the pen to be changed according to user tastes. The use of a quick-removing nib allows for a double-tipped nib to be used, with different writing tips, and easy swapping by the pen user between writing tips.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority to U.S. Provisional Application Ser. No. 62/118,392, filed on 19 Feb. 2015, which is hereby incorporated by reference for all purposes. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates generally to fountain pens. In particular, fountain pens that are capable of using a variety of different unconventional fluids for inks, such as wine, juice, soy sauce, etc., are described. 
         [0003]    Fountain pens, developed from historical writing instruments such as the dip pen and quill, is comprised of an ink reservoir which feeds a nib, with both components retained in a housing that facilitates use of the pen. These basic components and the essential design of a fountain pen have been known for centuries. Despite the widespread adoption of more modern writing implements such as ball-point pens, fountain pens continue to enjoy a widespread usage by enthusiasts who employ them for artistic purposes, nostalgia, or to provide a more formal flourish in communications. The nib of a typical modern fountain pen is made of metal, which tapers to a pointed tip, and is split from the tip down a portion of its length. The split forms a channel that conveys ink from the pen&#39;s reservoir to the tip, to enable writing. Due to the split in the nib, writing with a typical fountain pen results in strokes of varying sizes depending upon the pressure used in writing. The greater the pressure used, the more the split opens at the tip, resulting in an increasingly broad stroke. This split also results in a fountain pen having a somewhat flattened contact point with the writing surface, which causes the pen&#39;s writing performance to vary depending upon the angle with which the writer holds the pen. 
         [0004]    Dip pens, a predecessor to the fountain pen as mentioned above, can be purchased with nibs that are constructed using glass or a similarly hard material, shaped to a conical point. Instead of a split for conveying ink, multiple channels are cut into the surface of the nib, which act as small reservoirs. The pen is used by periodically dipping the nib into an ink well, which replenishes the ink held in the nib channels. These channels are often cut in a spiral fashion to increase the amount of ink the pen can retain between dips. The use of such a conical nib enables more consistent stroke widths, as the width of the nib in contact with the writing surface does not vary according to writing pressure. Furthermore, writing with a glass nib is slightly easier for left handed writers as compared to a fountain pen, as the nib comes to a slightly rounded conical point and is less sensitive to the angle at which the writer holds the pen. 
         [0005]    Known fountain pens are not entirely satisfactory for the range of applications in which they are employed. For example, the performance of existing pens is highly dependent upon the viscosity and type of ink used. The small channels and passageways present on metal nib fountain pens can become clogged if unsuitable fluids are used for ink, resulting in diminished writing performance. Similarly, ink with too high a viscosity may not flow easily. With their simplistic design, dip pens are more immune to clogging, but lack the reservoir of a fountain pen that enables relatively continuous writing. Furthermore, currently available glass nib dib pens usually have a nib that is integral to the body of the pen. Should the nib break, the pen is essentially rendered useless and must be discarded. 
         [0006]    Thus, there exists a need for improved fountain pens that improve upon and advance the design of known fountain and dip pens. Examples of new and useful fountain pens relevant to the needs existing in the field are discussed below. 
         [0007]    Disclosure addressing one or more of the identified existing needs is provided in the detailed description below. Examples of references relevant to fountain pens include U.S. Pat. No. 1,205,004, and Chinese Patent CN 202491558 U. The complete disclosures of the above patents and patent applications are herein incorporated by reference for all purposes. 
       SUMMARY 
       [0008]    The present disclosure is directed to a modular fountain pen useable with inks of varying viscosities. The fountain pen utilizes a nib with exterior grooves for conveying ink, which removably fits into a coupler that places the nib in fluid communication with a reservoir by way of a central ink tube. The coupler removably secures into a housing, which is closed on its opposite end by a rotating end cap designed to engage the ink reservoir so as to allow the pen user to adjust the internal volume of the reservoir. The use of O-rings to assemble the pen allows for quick assembly and disassembly, which further allows the pen to be easily cleaned between uses to accommodate fluid inks that may leave heavy residues. The quick assembly and disassembly also allows for the appearance of the pen to be changed according to user tastes. The use of a quick-removing nib allows for a double-tipped nib to be used, with different writing tips, and easy swapping by the pen user between writing tips. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1A  is a side elevation view of a first example of a modular fountain pen. 
           [0010]      FIG. 1B  is an exploded view of the modular fountain pen shown in  FIG. 1A  depicting he arrangement of it various components. 
           [0011]      FIG. 2  is a side elevation view of the nib that is part of the modular fountain pen shown in  FIG. 1B . 
           [0012]      FIG. 2A  is a cross section view from the center of the nib that is shown in  FIG. 2 . 
           [0013]      FIG. 2B  is a cross section view from the tip of the nib that is shown in  FIG. 2 . 
           [0014]      FIG. 3  is a cross section view of the coupler that is part of the modular fountain pen shown in  FIG. 1B . 
           [0015]      FIG. 4  is a cross section view of the nib grip that is part of the modular fountain pen shown in  FIG. 1B . 
           [0016]      FIG. 4A  is a cross section view through the center of the nib grip that is shown in  FIG. 4 . 
           [0017]      FIG. 5  is a cross section of the ink tube that is part of the modular fountain pen shown in  FIG. 1B . 
           [0018]      FIG. 6  is a side elevation view of the rotating end cap that is part of the modular fountain pen shown in  FIG. 1B . 
           [0019]      FIG. 7  is a series of side perspective views of possible variations of the exterior appearance of the modular fountain pen shown in  FIG. 1A . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The disclosed modular fountain pens will become better understood through review of the following detailed description in conjunction with the figures. The detailed description and figures provide merely examples of the various inventions described herein. Those skilled in the art will understand that the disclosed examples may be varied, modified, and altered without departing from the scope of the inventions described herein. Many variations are contemplated for different applications and design considerations; however, for the sake of brevity, each and every contemplated variation is not individually described in the following detailed description. 
         [0021]    Throughout the following detailed description, examples of various modular fountain pens are provided. Related features in the examples may be identical, similar, or dissimilar in different examples. For the sake of brevity, related features will not be redundantly explained in each example. Instead, the use of related feature names will cue the reader that the feature with a related feature name may be similar to the related feature in an example explained previously. Features specific to a given example will be described in that particular example. The reader should understand that a given feature need not be the same or similar to the specific portrayal of a related feature in any given figure or example. 
         [0022]    With reference to  FIGS. 1A and 1B  a first example of a fountain pen, fountain pen  10 , will now be described. Fountain pen  10  functions to incorporate the reservoir and ease of use found in a traditional metal nib fountain pen with the flexibility of usage of the glass nib dip pen. Additionally or alternatively, fountain pen  10  can be used to provide a modular fluid ink writing system. The various components can be made independently replaceable, with variations produced that are tailored to specific uses and types of inks. 
         [0023]    Fountain pen  10  addresses many of the shortcomings existing with conventional fountain pens. For example, the componentized design of fountain pen  10  enables the components that handle transfer of ink onto paper to be swapped according to the type of ink and writing surface that are used, thereby enabling use of a single pen with a greatly expanded variety of inks and writing media. The range of different inks available can also include nonconventional fluids, such as wine, soy sauce, juice, or any other staining fluid of suitable viscosity. Alternatively or in addition, the nib  100  can be swapped to change the shape of the nib tip to suit different writing styles, or if the nib  100  breaks for replacement. Further aiding in the use of a variety of non-conventional inks, the modular construction enables easy teardown of fountain pen  10  for cleaning, as various non-conventional inks may otherwise leave residues that build up over time and hinder performance. 
         [0024]    Depicted in  FIGS. 1A and 1B , the primary components of fountain pen  10  include a nib  100 , coupler  110 , ink reservoir  130 , main body  140 , and rotating end cap  150 . Nib  100  is protected by a cap  160  that can be removably secured to fountain pen  10  when the pen is not in use. Nib  100  inserts into coupler  110  by way of a nib grip  120 , which is in turn inserted into coupler  110 . Ink stored inside reservoir  130  is conveyed to nib  100  by means of an ink tube  170 . The various components can be held in place using a series of O-rings  112  to allow for easy tear-down and assembly. 
         [0025]    As can be seen in  FIG. 2 , nib  100  is double-ended, with a first end  200  and a second end  210 . Each end can optionally be identical, allowing either end of the nib  100  to be used for writing, and also allowing the nib  100  to be inserted either direction into fountain pen  10 . Running along the length of nib  100  are a series of ink channels  222 , from the tip on first end  200  to the tip on second end  210 , which deliver ink to the tip that is in contact with the writing surface. Nib  100  is ideally made of glass, plastic, metal, wood, foam, or any other material or combination of materials that is suitable for carrying ink to a writing surface and has durability sufficient to be used with the intended writing surfaces. 
         [0026]      FIGS. 2 and 2A  show the ink channels  222  preferably arranged in a spiral fashion, to increase their length and corresponding ink holding capacity, as well as to reduce or prevent excessive running of ink from the nib. The average number of channels ranges from 6 to 12 in total. As can be seen in  FIG. 2 , all or a portion of the ink channels  222  can alternatively be made straight, where first end  200  and second end  210  would have different arrangements of ink channels  222 . Ink channels  222  must run to each of first end  200  and second end  210 .  FIG. 2B  shows this arrangement in the context of second end  210 , with ink channels  222  sizing down but terminating at the end so as to convey ink directly onto the writing surface. The width of each of the ink channels  222  can vary as necessary to suit the type of ink to be used. For example, narrower, deeper ink channels  222  may better accommodate thinner and more fluid inks, while shallower, wider ink channels  222  could be employed where thicker, more viscous ink is employed. Still other variations could implement ink channels  222  as holes or tubes that run inside the body of nib  100  and exit proximate to first end  200  and/or second end  210 , thereby keeping ink from being exposed on the surface of nib  100 . 
         [0027]    The nib  100  depicted has approximate dimensions of 1 cm (10 mm) diameter, and 4 cm (40 mm) in length. However, these dimensions can be varied to suit the overall design of fountain pen  10 . Other implementations may have a narrower or larger diameter as necessary to fit within the coupler  110  and nib holder  120 . For more slender pen designs, a nib  100  diameter of less than 5 mm (0.5 cm) may be used. Nib  100  is placed into fountain pen  10  by inserting it into nib grip  120 , and thence into coupler  110 , which will be discussed in greater detail below. Ink channels  222  can be shaped around the midsection of nib  100 , between first end  200  and second end  210 , to facilitate retention of the nib  100  when it is inserted into nib grip  120 . While the example nib  100  shown in  FIG. 2  has differing first end  200 , which is rounded, and second end  210 , which is flat, these ends could be identical. In other variations, first end  200  and second end  210  may be tailored with different specific shapes to match a desired style of writing, e.g. first end  200  may have a broader point and second end  210  may have a finer point for varying stroke sizes. Other alternatives may have specific shaped tips, such as oblong, to enable the fountain pen  10  to be used for calligraphy. By way of example of shaping, the nib  100  may be tapered or ground on one end at an angle (e.g. 45 degrees) to enable a broader writing width. Still other alternatives may have second end  210  shaped to facilitate transfer of ink from the ink reservoir  130  to the tip of first end  200 , rather than providing a second tip for writing. Where the first end  200  and second end  210  of nib  100  are both functional for writing, a user of fountain pen  10  may easily convert from one writing tip to a second style by removing the nib  100  from the nib grip  120 , inverting it, and reinserting into the nib grip  120 . 
         [0028]    In the example shown in  FIG. 3 , coupler  110  is shown in greater detail. Coupler  110  includes a nib grip cavity  300 , an ink delivery channel  310  which connects the top of nib grip cavity  300  to the bottom of reservoir cavity  320 , and an attachment surface  340  which allows the coupler  110  to be removably affixed to main body  140  for assembly of the fountain pen  10 . As assembled into the main body  140 , coupler  110  serves as the lower half of fountain pen  10  as well as the grip for the pen user. Coupler  110  can be manufactured of plastic, metal, wood, composites, or any other material suitable to act as a grip surface and support the nib  100  and associated pressures experienced while being used for writing. The exterior of coupler  110  that is used as the grip for the user can optionally be further coated and/or shaped in such a fashion as to provide a more comfortable and contoured grip surface for writing. Into nib grip cavity  300  is inserted nib grip  120 , which in turn receives nib  100  and holds nib  100  in place. 
         [0029]    As can be seen in  FIGS. 1B and 3 , coupler  110  can be attached to main body  140  by way of attachment surface  340 , which possesses a series of channels for accommodating O-rings  112 . As coupler  110  is inserted into main body  140 , O-rings  112  are compressed and hold coupler  110  securely into main body  140  by friction. Alternatively, attachment surface  340  can be implemented as a threaded surface, with a corresponding threaded portion on main body  140  into which coupler  110  is screwed. A person skilled in the relevant art will appreciate that threaded and O-ring press-fit methods of attachment are only two possible examples of ways to removably affix the coupler  110  to the main body  140 . Any method for removably affixing the coupler  110  to the main body  140  in a fashion that allows for disassembly and reassembly, e.g. twist-lock, snapping mechanism, camming action, etc., can be utilized without deviating from the disclosed invention. 
         [0030]    O-rings  112  are standard O-rings that are well known in the mechanical arts, and can be manufactured of any material such as rubber, silicone, plastic, viso-elastic polymer, or other similar material now known or later developed that provides for a compression fit friction seal. 
         [0031]      FIG. 4  depicts nib grip  120  in a longitudinal cross-section. Nib grip  120  is substantially tubular, with a nib cavity  122  forming the center of nib grip  120 . Nib grip  120  is inserted into nib grip cavity  300  into coupler  110 . Nib  100  is in turn inserted into the nib cavity  122 , which is shaped to retain the nib  100  by pressure. As described above, nib  100  may be complementarily shaped to facilitate being retained in the nib cavity  300 . Nib holder  120  is shaped and constructed of a material so as to facilitate its retention within coupler  110 , which likewise may be complementarily shaped to facilitate the retention of nib holder  120 . Nib holder  120  may be manufactured of plastic, rubber, silicone, or any other material that is useful for retaining nib  100  under pressure, while simultaneously being retained in coupler  110 . Alternatively, nib grip  120  can be made integral to or as part of the coupler  110 . 
         [0032]      FIG. 4A  presents a cross-section across the axis of nib grip  120 , demonstrating the internal structure of nib cavity  122 . Specifically, the interior of nib cavity  122  includes a plurality of ridges  124 , which are interspaced with grooves  126 . Ridges  124  help improve upon the grip of nib  100 , while also facilitating ink transfer. Ridges  124  and grooves  126  preferably run the length of nib cavity  122 , but could only extend partially. Furthermore, while  FIG. 4A  presents a possible preferable internal structure for nib cavity  122 , nib cavity could also be implemented with a smooth surface, omitting ridges  124  and grooves  126 , or with more or less ridges, or potentially with any varying pattern that allows nib  100  to be removably secured within nib grip  120  in a fashion that promotes ink transfer across nib  100 . 
         [0033]    Referring to  FIG. 5 , ink tube  170  that conveys fluid ink from reservoir  130  to nib  100  is depicted. Ink tube  170 , as its name suggests, is substantially a cylindrical tube with a hollow central channel  172  through which fluid ink moves. Ink tube  170  inserts into ink delivery channel  310  within coupler  110 , and provides a reservoir interface  176  as well as a nib interface  174 . Nib interface  174 , as depicted in  FIG. 5 , is shown as a beveled surface at the end of hollow central channel  172 , which is shaped to closely accommodate an end of nib  100  so as to convey ink to ink channels  222 . The bevel angle preferably approximates the taper angle of nib  100 , as can be seen in  FIG. 2 . Reservoir interface  176  is shaped to insert into reservoir  130  to receive ink into hollow central channel  172 . Ink tube  170  is shaped to securely insert into ink delivery channel  310  and, in conjunction with the shape of the cavities in coupler  110 , hold both nib  100  and reservoir  130  in a secure position in fluid communication to facilitate writing. Ink tube  170  can be constructed from metal, plastic, rubber, wood, composites, or any combination of the foregoing or any other suitable material now known or later developed that can withstand the stresses imposed by contact with nib  100  during writing, and which will convey ink from reservoir  130  to nib  100  without unduly restricting flow. 
         [0034]      FIG. 1  also shows ink reservoir  130 , which can be filled with a desired fluid for ink. Ink reservoir  130  interfaces with reservoir interface  176  for transfer of the ink to the top of nib  100  through ink delivery tube  170 . In the example ink reservoir  130  shown in  FIG. 1 , the ink reservoir  130  has an ink control mechanism in the form of a piston assembly located opposite to where the ink reservoir  130  interfaces with ink tube  170 , to facilitate filling of the ink reservoir  130 , and to pressurize the ink reservoir  130  if necessary. In the selected reservoir  130 , this piston assembly is controlled by a knob located on the end of reservoir  130 , which raises or lowers the internal piston of reservoir  130  depending upon the direction in which the knob is rotated. As the internal piston is raised or lowered, the corresponding volume of reservoir  130  is increased or decreased, respectively, thereby enabling the reservoir to be filled or emptied. This type of reservoir mechanism is well known in the art. Other example ink control mechanisms may include a spring-powered piston, pneumatic piston, or air pressurization of the ink reservoir  130 . In some possible implementations, ink reservoir  130  may optionally interface with reservoir interface  176  by way of a one-way valve mechanism located within the ink reservoir  130 , in order to facilitate disassembly of the fountain pen  10  without the need to empty the ink reservoir  130  or risk spilling of any ink contained therein. 
         [0035]    Turning attention to  FIG. 6 , rotating end cap  150  is shown. End cap  150  has an attachment surface  602  which is designed to allow end cap  150  to be removably affixed to the top end of main body  140 . Attachment surface  602  is depicted as a channel for receiving an O-ring  112 , but can be implemented using screw threads, press fit, or any other method that enables secure yet removable attachment to the top of main body  140 . Inside end cap  150  is a mating surface  600  that can optionally contact ink reservoir  130  so as to allow any piston mechanism or other ink control mechanism in the ink reservoir  130  to be actuated without needing to disassemble fountain pen  10 . Correspondingly, end cap  150  has a top surface  610  which allows the ink control mechanism to be actuated when the fountain pen  10  is assembled. Preferably, end cap  150  is comprised of an annular outer sleeve that contacts main body  140 , into which a central assembly comprised of top surface  610  and mating surface  600  are inserted in such a fashion as to allow the central assembly to rotate. This rotational motion is conveyed via mating surface  600  to the mechanism in reservoir  130  that controls its volume, as described above. End cap  150  can be made of plastic, metal, wood, or any other material suitable for enclosing the fountain pen  10  and allowing for actuation of the ink control mechanism. A person skilled in the relevant art will appreciate that any method for removably affixing the end cap  150  to the main body  140  in a fashion that allows for disassembly and reassembly, e.g. twist-lock, snapping mechanism, camming action, etc., can be utilized without deviating from the disclosed invention. 
         [0036]    Examples of main body  140  are shown in  FIG. 7 . Main body  140  is essentially a hollow tube, with attachment surfaces located at either end. As depicted in  FIG. 7 , the exterior of the main body  140  can be fitted with a variety of decorations for aesthetic and/or functional purposes. The main body can be manufactured from plastic, metal, wood, composites, or any other material that is suitable for enduring typical stresses experienced by a fountain pen in use. Furthermore, owing to the modular nature of the fountain pen  10 , the fountain pen  10  can be easily disassembled and the main body  140  replaced with another main body  140  with a different exterior appearance, allowing a user to quickly change the aesthetic appearance of the fountain pen  10 . In alternative embodiments, the exterior of the main body  140  can be implemented as a separately removable sheath that fits over an inner tube to comprise main body  140 , where the removable sheath can be swapped to change the aesthetic appearance of the fountain pen  10 , with the interior tube being constructed of potentially different materials better suited to provide a durable structure to fountain pen  10 .  FIG. 7  shows some example usages of the fountain pen  10 . In addition, different aesthetic appearances of fountain pen  10  are demonstrated, including a different, transparent appearance for coupler  110 . 
         [0037]    Assembly of fountain pen  10  is accomplished by inserting nib grip  120  into nib grip cavity  300 , and then inserting ink tube  170  through nib grip  120  and through ink delivery channel  310  so as to protrude into both reservoir cavity  320  and nib grip cavity  300 . Ink reservoir  130  is then inserted into reservoir cavity  320  of coupler  110  so as to engage reservoir interface  176 . Coupler  110  with reservoir  130  is then inserted into the main body  140  so as to enclose the ink reservoir  130  inside main body  140 . The coupler  110  is then removably affixed to one end of the main body  140 , and rotating end cap  150  is removably affixed into the opposite end, with rotating end cap  150  potentially engaging an ink control mechanism located within the ink reservoir  130 . Nib  100  is inserted into nib grip  120  in nib grip cavity  300 . Cap  160  can be placed over nib  100  and the exposed end of coupler  110 , and removably secured to either coupler  110  or main body  140 . Cap  160  can be secured by a snap mechanism, press fit, threads, or any other method now known or later developed in the art for typically securing a cap to a pen when the pen is not in use. 
         [0038]    The disclosure above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in a particular form, the specific embodiments disclosed and illustrated above are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed above and inherent to those skilled in the art pertaining to such inventions. Where the disclosure or subsequently filed claims recite “a” element, “a first” element, or any such equivalent term, the disclosure or claims should be understood to incorporate one or more such elements, neither requiring nor excluding two or more such elements. 
         [0039]    Applicant(s) reserves the right to submit claims directed to combinations and subcombinations of the disclosed inventions that are believed to be novel and non-obvious. Inventions embodied in other combinations and subcombinations of features, functions, elements and/or properties may be claimed through amendment of those claims or presentation of new claims in the present application or in a related application. Such amended or new claims, whether they are directed to the same invention or a different invention and whether they are different, broader, narrower or equal in scope to the original claims, are to be considered within the subject matter of the inventions described herein.