Abstract:
A drawing tool for creating stripped patterns or multi-colored lines, such as rainbows. The drawing tool includes a set of removable cartridges of varying sizes, nib shapes and colors, each of which is interchangeable with others of its own size or with a set ratio of lager or smaller cartridges.

Description:
BACKGROUND  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates to drawing tools. Specifically this invention relates to a drawing tool that allows several markers to be used simultaneously, the individual markers being replaceable and interchangeable.  
           [0003]    2. Background  
           [0004]    Conventional drawing utensils are primarily based on a pen or pencil design. A user grips the cylindrical body of the drawing utensil with the marking end pointing away from the user. The nib (i.e., the marking portion) of the utensil is applied to a flat surface of a receiving medium such as paper or canvas in order to color or mark its surface.  
           [0005]    Conventional markers are examples of drawing utensils. A conventional marker is a cylindrical tool with a nib protruding from the distal end. Ink is stored within the cylindrical body of the marker. The nib may have a removable covering or cap that protects the nib from drying out. A user grips the marker by the cylindrical body and applies the nib to a surface to dispense ink onto that surface. Each mark contains a single color of ink. Different colored markers may be used individually to create a picture or drawing.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    Embodiments of the invention are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.  
         [0007]    [0007]FIG. 1 a  is an illustration of a drawing tool with its cap removed.  
         [0008]    [0008]FIG. 1 b  is an illustration of a drawing tool with its cap covering a set of nibs.  
         [0009]    [0009]FIG. 2 a  is an illustration of a medium sized set of marker cartridges.  
         [0010]    [0010]FIG. 2 b  is an illustration of a side view of the medium sized marker cartridge of FIG. 2 a.    
         [0011]    [0011]FIG. 2 c  is an illustration of a small sized set of marker cartridges.  
         [0012]    [0012]FIG. 2 d  is an illustration of a side view of the medium sized marker cartridge of FIG. 2 c.    
         [0013]    [0013]FIG. 2 e  is an illustration of a flanged nib.  
         [0014]    [0014]FIG. 2 f  is an illustration of the flanged nib of FIG. 2 e  in an expanded position.  
         [0015]    [0015]FIG. 3 is an illustration of a drawing tool with a set of small markers.  
         [0016]    [0016]FIG. 4 a  is an illustration of small size drawing tool.  
         [0017]    [0017]FIG. 4 b  is an illustration of a medium size drawing tool.  
         [0018]    [0018]FIG. 4 c  is an illustration of a large size drawing tool.  
         [0019]    [0019]FIG. 4 d  is an illustration of a medium size drawing tool with angled nib position.  
         [0020]    [0020]FIG. 5 is an illustration of a retractable drawing tool.  
         [0021]    [0021]FIG. 6 is an illustration of a hinged case drawing tool.  
         [0022]    [0022]FIG. 7 is an illustration of a tiered marker drawing tool.  
         [0023]    [0023]FIG. 8 is an illustration of a snap fit marker set.  
     
    
     DETAILED DESCRIPTION  
       [0024]    [0024]FIG. 1 a  is an illustration of a drawing tool  101  for using multiple markers. Drawing tool  101  includes main housing  117 . Main housing  117  may be constructed of plastic, including thermoplastic and thermoset plastic, metal, natural materials or similar materials. Housing  117  defines an interior compartment or set of compartments for holding a set of cartridges  111 . In one embodiment, housing  117  is translucent enabling a user to easily discern the colors, number and placement of markers within the housing  117 . Markers are composed of a cartridge  111  and nib  103 . In another embodiment, housing  117  is opaque.  
         [0025]    In one embodiment, cartridges  111  have a squared or block shaped body. A single housing  117  may have sufficient space to hold several cartridges depending on the size of the cartridges  111 . In another embodiment, cartridges may have any shape, including cylindrical, triangular or similar shape. The interior chamber of housing  111  has a complementary shape to the shape of the cartridges  111  to be placed therein in order to facilitate holding the cartridges  111  in a firm position while the drawing tool  101  is in use.  
         [0026]    In one embodiment, cartridges  111  may be inserted into the back end of drawing tool  101 . A cover  119  may be snap fitted, latched or similarly connected to housing  117 . Cover  119  may be removed to provide access to cartridges  111 . Cartridges  111  slide into housing  117  nib  103  first. They are limited from exiting housing  117  at the front of marker  101  by the shape of a nib port  121 , which allows the nib  103  of cartridge  111  to protrude but prevents the wider body from moving forward.  
         [0027]    In one embodiment, drawing tool  101  has a set of ridges extending along the length of the walls of an interior cavity of the drawing tool  101 . These ridges serve to guide the placement of cartridges  111  within the drawing tool  101 . The ridges may match the width of a cartridge defining a set of slots in which to place each cartridge  111 . The ridges may match a groove in the cartridge  111  to guide its orientation and placement within the cavity. These ridges may interact with the cartridges to define their positions dependent on the size of the cartridges. A small size cartridge may fit in a ridge-defined slot. A medium sized or large size cartridge may have matching grooves for the same ridge pattern.  
         [0028]    In one embodiment, each cartridge has a groove  109  along its outer surface. This groove  109  has a shape that is complementary to a ridge in the interior cavity of housing  117 . The ridge must be matched with groove  109  in order to fit cartridge  111  into its slot. Aligning the ridge and groove  109  also aligns nib  103  of cartridge  111  so that it is properly oriented in relation to drawing tool  101  or the nibs of other cartridges. The ridge guides the cartridge as it slides forward preventing the nib  103 , if exposed, from contacting the inner surface of housing  117  thereby protecting the inner surface from repeated ink markings. Cartridges  111  slide forward until nib  103  reaches a nib port  121  of drawing tool  101  at the front end. Nib port  121  has dimensions that are less than that of the body of cartridge  111  thereby preventing cartridge  111  from sliding out through the front of drawing tool  101 . However, the nib  103  of cartridge  111  has a smaller dimension than the body allowing it to pass through nib port  121 .  
         [0029]    In another embodiment, cartridges may be front loaded by a user. A face of nib port  121  may be removed or altered to provide sufficient space to place the body of cartridge  111  into housing  117 . The face is replaced or nib port  121  returned to its original dimensions. The movement of the cartridge  111  through the interior of the drawing tool  101  is guided by the complementary groove  109  and ridge combination. The back end of the interior cavity is a limiting wall of the housing preventing the cartridge  111  from sliding past the position where the nib  103  of the cartridge  111  protrudes a desired distance from the front end of the drawing tool  101 .  
         [0030]    In another embodiment, the groove and ridge structure may be reversed with grooves in housing  117  and ridges on cartridges  111 . Similar engagement and guidance structures may be used to replace the groove and ridge structure or in combination with it. A form fit, rail, tapered fit, or similar guidance structure may be used. In a further embodiment, cartridges may be clamped, latched, snap-fit or similarly held in place.  
         [0031]    In one embodiment, housing  117  may define sufficient space for three medium sized cartridges  111 . Each cartridge  111  is a sealed container for holding an ink or similar liquid having a single outlet at its distal end. In one embodiment, the outlet is filled by a nib  103  that protrudes from the cartridge  111 . Nib  103  is composed of plastic, fiber, felt or similar material for dispensing ink and similar liquids at a predetermined rate. In one embodiment, nib  103  may have a chisel like shape with a linear surface  107  for a nib. Nib  103  is connected to a tampon in the interior of the cartridge, which is an absorbent material that holds the majority of the ink and maintains a supply of ink to nib  103 . In one embodiment, nib  103  has flange structures, which when used expand the width of the nib. These expanding flanges may fill in all or most of the gaps between the nibs  103  of drawing tool  101  to allow the creation of a striped or rainbow pattern without any gaps or with minimal gaps between the stripes. The flanges are sized so as to avoid contact with neighboring nibs to prevent bleeding of ink between nibs. In another embodiment, a roller ball or similar dispensing mechanism is attached to the cartridge  111  outlet.  
         [0032]    In one embodiment, the dimensions of each cartridge  111  body are roughly equivalent such that each cartridge  111  may be removed from drawing tool  101  and replaced by a standard sized cartridge, for example when one cartridge is empty. Similarly, the position of each cartridge  111  is interchangeable in drawing tool  101 . Each cartridge has the same groove structure or similar guidance structure to guide it into the desired position in drawing tool. Each cartridge may contain an ink of a different color, contain special ink such as a ‘magic ink’ a clear ink that reacts with other inks to alter their color, or contain a similar marking liquid. The cartridges can be arranged by desired color within drawing tool  101  to allow the easy creation of multicolor stripes or rainbows by applying drawing tool  101  to a surface with a single stroke. Multiple cartridges of the same color ink may be used to get a wider ink swath from each stroke.  
         [0033]    In another embodiment, cartridges  111  may have varying sizes. Cartridges of varying sizes may be interchangeable in defined ratios. A small size cartridge may have cartridge body dimensions roughly half that of a medium size cartridge. Two small size cartridges can then be placed in a medium size chamber or holding structure. The combination of cartridges can be mixed and matched to create a drawing tool  101  with the desired combination of colors and marker nib sizes.  
         [0034]    In one embodiment, a cap  105  covers the nibs  103  of cartridges  111  when in a closed position. FIG. 1 a  shows the cap in an open position. The cap when in an open position can be attached to the rear of drawing tool  101  by a form fit, snap fit, latch or similar mechanism. FIG. 1 b  shows drawing tool  101  with cap  105  in a closed position. Cap  105  in the closed position creates a seal around nibs  103  of cartridges  111  preventing the flow of air across the nibs and thereby preventing the drying out of nibs  103  and cartridges  111  when not in use.  
         [0035]    [0035]FIG. 2 a  is an illustration of a set of medium sized cartridges  111 . Each cartridge has a roughly identical body dimension with a width A. In one embodiment, the width of the medium sized cartridge is nine millimeters (mm). FIG. 2 b  is an illustration of a side view of the medium sized cartridge  111  having a chisel shaped nib  103 . This cartridge is medium sized with a height A′. FIG. 2 c  is an illustration of a set of small sized cartridges. Small cartridges  211  have a width B that is approximately half the width of medium sized cartridges  111  having width A. Thus, two small cartridges  211  can replace a single medium size cartridge  111 . In one embodiment, small cartridge width is approximately four millimeters. A and A′ may be but need not be equal.  
         [0036]    In one embodiment, small cartridges  211  have beveled edges such that two together form a groove similar to the groove of a medium sized cartridge. The beveled edges and ridge of the housing guide a cartridge  211  during insertion and hold a cartridge in place with a form fit. Each smaller cartridge  211  has a nib  203  with the same basic shape as the medium sized cartridge nib  103  such as pointed, chisel shaped and similar shapes. In another embodiment, the small cartridges  211  have straight edges and fit between the ridges of the housing.  
         [0037]    [0037]FIG. 2 d  illustrates a side view of a small sized cartridge  211  having a small sized nib  203 . The small sized cartridge  211  has a height A′ matching the height of the medium sized cartridge  111 . The sizes of cartridges can be any size appropriate for being held by a user in sets of one or more. The cartridge body dimensions of height, width and length can be varied such that a standard height, width and length are used for all cartridges. The relative height and width of cartridges can be varied such that the cartridge may have a roughly elongated square or rectangular shape. In another embodiment, the cartridges may have cylindrical, triangular or similar shaped body.  
         [0038]    [0038]FIG. 2 e  is an illustration of the nib end of a cartridge  231  with a nib  233  having flanged edges. Cartridge  231  and nib  233  may be of any size. Nib  233  has flanged edges  235 . Flanged edges  235  are flexible portions of the nib that bend to elongate the width of nib  233 . In one embodiment, flanged edges  235  may be created by forming a typical chisel shaped nib  233 . The nib is given a concave shape by cutting out a central convex section of the linear tip  237  surface of nib  233 . This results in a concave nib  233  shape including pointed or flanged edges  235 .  
         [0039]    [0039]FIG. 2 f  illustrates nib  233  in an expanded position. Nib  233  may be in an expanded state when pressed against a surface or under similar circumstances. The flanges  235  expand the width of the nib tip  237 . This enables the drawing of broader lines with less gap between the lines drawn by cartridges in a drawing tool such as described herein. The flanges are sized to prevent contact with nibs including other flanged nibs in adjacent cartridges to prevent the bleeding of ink between the nibs. Flanges  235  also function to provide a broader nib while allowing the nib to pass through the interior cavity and through the nib port  121  defined by the housing  117  without marking the interior of drawing tool  101  or obstructing the sliding of the cartridge.  
         [0040]    [0040]FIG. 3 is an illustration of a drawing tool  301  housing a set of small cartridges  307 . Two small cartridges  307 ,  309  are disposed within housing  303  in place of a single medium size cartridge. Nib port  311  is a single continuous opening in housing  303 . The nib port  311  opening may have any shape that allows the nibs of small and medium cartridges to protrude from drawing tool  301  when the drawing tool cap is in an open position.  
         [0041]    [0041]FIGS. 4 a - 4   d  illustrate different size drawing tools, and cartridge configurations demonstrating the interchangeability and flexibility of the drawing tool design. FIG. 4 a  is an illustration of a small size drawing tool  401 . Small drawing tool  401  can accommodate three small markers. In another embodiment, small drawing tool  401  may accommodate two through five small markers and one or two medium sized markers or various combinations thereof. FIG. 4 b  is an illustration of a medium sized drawing tool  403 , which can accommodate three or more medium markers, six or more small markers or combinations thereof. Cartridge slots may be left open so that fewer markers of any size may be used in any size drawing tool.  
         [0042]    [0042]FIG. 4 c  is an illustration of a large drawing tool  405  including a large marker  407 . A large marker may have any ratio to medium or small marker that is a ratio of whole numbers. In one embodiment, the large marker  407  has a ratio of one to three with the medium markers. In one embodiment, the large marker  407  has two sets of grooves in the cartridge body to allow it to slide into three chambers defined with the housing by two dividing ridges. In one embodiment, large marker  407  has a width of thirty millimeters. The large marker  407  may employ any of the guidance or attachment structures used by the medium or small sized cartridges.  
         [0043]    [0043]FIG. 4 d  is an end view illustration of a drawing tool  409  having an angled nib configuration. In one embodiment, drawing tool  409  houses the cartridges at an angle such that the flat linear edge of each nib  411  is set at an angle from the central plane of the drawing tool. The angle allows a striped rainbow pattern to be drawn in a single stroke having a minimal or no gap between the lines of the pattern. Also, this allows colors in a striped pattern to be deliberately overlapped depending on the angle at which the stroke is made. In another embodiment, an angled grip in line with the angle of the nibs  411  is provided to assist the user in drawing a striped pattern. The angled grip may be a part of the housing or attached to the housing of the drawing tool  409 .  
         [0044]    [0044]FIG. 5 is a drawing tool with retractable cartridges. In one embodiment, drawing tool  501  includes a base housing  503  and a rear cap  505  to allow access to cartridges  511  for replacement and exchange. An optional cap  507  is removably attached to cover the nib ports  517 . Each cartridge  511  is removably attached to brace  513 . Brace  513  includes a mechanism such as a form fit, snap fit, latch or similar device to hold each cartridge  511 . Brace  513  is attached to slide  515  through slit  519 . A user moves slide  515  to advance or retract the nibs of cartridges  511  through nib port  517 . In one embodiment, slide  515  locks into the advanced and retracted positions by a snap fitting, latching mechanism, friction fit, or similar device. In another embodiment, retracting and advancing the cartridges causes doors on nib ports  517  to open and close to prevent the nibs from drying out while not in use in the retracted position.  
         [0045]    [0045]FIG. 6 is an illustration of a hinged marker with extra storage space for spare cartridges. In one embodiment, drawing tool  601  includes a lower housing  603  and an upper housing  605 . Lower housing  603  is coupled to upper housing by a hinge mechanism  615  or similar mechanism. In the open position, drawing tool  601  allows access to cartridges  611  whose nibs are positioned for use and cartridges  613  in a storage area of drawing tool  601 . Upper housing  605  and lower housing  603  are held together by a latch, snap fit, form fit or similar mechanism when in a closed position. A set of ridges  607  in the upper housing  605  and lower housing  603  define positions for small cartridges  613 , medium cartridges or large cartridges to be inserted interchangeably. A limiting wall or ridge  609  prevents cartridges  611  from sliding out of position along with the ridges  607  and contours of the exit port  617 .  
         [0046]    [0046]FIG. 7 is an illustration of a tiered drawing tool  701 . In one embodiment, drawing tool  701  retains standard cartridges  711  in a tiered alignment. Nibs  703  of cartridges  711  each protrude a set distance from the drawing tool  701 . In one embodiment, nibs  703  have angled outer edges in line with the angle of the cartridge arrangement to create a linear alignment of outer nib edges to facilitate the application of the nibs  703  to a surface to be marked. This configuration may facilitate drawing by providing a more natural resting and gripping angle for a user when holding drawing tool  701  and applying it to mark a surface.  
         [0047]    [0047]FIG. 8 is an illustration of a set of cartridges that can be directly coupled to one another in an interchangeable manner. In one embodiment, each cartridge  811  has a male coupling  815  and female coupling  817 . Any cartridge  811  with the male female coupling mechanism may be coupled to any other cartridge with at least a male or female coupling. Cartridge  811  with both male and female couplings is interchangeable with any other cartridge with the same coupling mechanism. Thus, cartridges may be coupled together to form a single drawing tool allowing a user to determine the cartridges to be used in the combined drawing tool. The couplings are positioned to connect the cartridges  811  in any order allowing a user to determine the pattern to be drawn. The couplings also position the nibs of the cartridges to have a matching orientation in order to produce a defined pattern, such as a stripe pattern when stroked across a surface. In another embodiment, alternative coupling mechanisms may be employed including matching tongue and groove sections, latches, clamping devices, snap-fit or similar coupling devices.  
         [0048]    In another embodiment, each cartridge  811  has a female connection  817  on each side and discrete double-sided male connectors  815  are provided to permit maximal interchangeability of cartridges. Other embodiments contemplate interconnection with tongue and groove mechanisms, snaps, releasable adhesive, hook and loop material or any other manner in which the cartridges may be retained in interchangeable relation to each other.  
         [0049]    In the foregoing specification, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims. For example, an extra compartment in any of the designs may be included for the storage of markers. The general features of interchangeability, cartridge access mechanisms, retraction mechanisms, nib protection mechanisms and similar structures may be used in combination or omitted from any design in the spirit and scope of the invention. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.