Abstract:
A marking device for writing or drawing on a given surface can be made of any material that leaves a residue or makes legible marks on a surface. The marking device can be used to make precise lines or shapes on any material, including rough surfaces, such as, wood, concrete, drywall, tiles, etc. The marking device can consistently produce thin lines without needing any sharpening. The marking device can be attached to a support frame, which can serve as a handle for grasping and using the marking device. The support frame can further provide a housing to shield the marking device from damage when not in use. The marking device can be shaped as a razorblade and be configured to fit into any standard utility knife, which may serve as the support frame. Such an arrangement allows a utility knife to be reversibly converted into a carpenter pencil.

Description:
This application is a continuation of application Ser. No. 13/835,920, filed Mar. 15, 2013, which claims priority to U.S. Provisional Application Nos. 61/660,715, filed Jun. 16, 2012; 61/664,049, filed Jun. 25, 2012; 61/714,172, filed Oct. 15, 2012; and 61/714,885, filed Oct. 17, 2012, all of which are incorporated herein by reference in their entirety. 
    
    
     The present disclosure relates generally to razorblades that can be used as marking tools, and more specifically, to the design of razorblades that can be used with standard utility knives for writing or drawing on various materials. 
     Carpenters, builders, designers, contractors, and tradesmen in general regularly use carpenter pencils to draw or make legible marks on a variety of materials. Carpenter pencils generally have a rectangular or elliptical cross-section, which allows thick or thin lines to be drawn by rotating the pencil. The lead of a carpenter pencil has to be strong enough to withstand the stress of making marks on rough surfaces; at the same time, the lead has to be thin on at least one side to make precise lines that can be followed with a saw blade or any other cutting/sculpting tool. Wood-encased carpenter pencils also have to be frequently sharpened in order to make thin, accurate lines. The sharpening is typically done with a knife to trim the wood around the pencil lead, followed by polishing the pencil lead with a sandpaper to achieve a sharp edge. Sharpening can be avoided with mechanical carpenter pencils; however, mechanical pencils generally have other disadvantages, for example, their complex design makes it difficult to insert/retract the pencil leads; the jaws supporting the pencil lead causes it to break frequently under the stress of writing or drawing on rough surfaces; and further, the jaws often give way during use and cause the lead to slip into the body of the pencil. Moreover, carpenter pencils and other carpentry marking tools lack precision because they cannot be placed accurately against a straight drawing edge (e.g., a ruler or set squares) because of their non-round shape and bulky casing. 
     The present disclosure is directed towards the design of a marking device that can be used in place of a carpenter pencil to draw legible lines or shapes on various material, including rough surfaces, for example, concrete, wood, carpet, tiles, cardboard, drywall, stones, etc. The marking device of the present disclosure allows thin lines to be drawn without needing any sharpening or polishing. This provides a distinct advantage over wood-encased carpenter pencils, which have to be repeatedly sharpened, especially when writing or drawing on course surfaces that tend to wear out the pencil lead quickly. The marking device, on the other hand, can consistently provide a sharp edge, even when used on course surfaces. Further, the marking device provides a planar edge that can be aligned substantially perpendicular to a working surface and it can be placed accurately against a drawing tool to make straight and precise lines even on course surfaces. The marking device can be used for drawing lines or shapes that can serve as guides in cutting or sculpting the material. The marking device can also be used for writing dimensions or other instructions on a piece of working material. 
     The marking device of the present disclosure is designed for use with a support frame, which is configured to house at least a portion of the marking device therein. Such an arrangement protects the marking device from damage when not in use. The support frame also provides a handle for grasping and using the device. The support frame has a user-friendly design, which allows for swift and easy mounting of the marking device on and off the frame. 
     A first embodiment of the present disclosure is a marking blade. The marking blade comprises a planar razorblade having a longitudinally extending marking edge. At least a portion of the marking edge comprises a marking material that makes legible marks on various surfaces. 
     A second embodiment of the present disclosure is another marking blade, which comprises a thin plate configured as a razorblade. The thin plate includes a longitudinally extending marking edge, and at least a portion of the marking edge comprises a pocket configured to a house a marking tip. The marking tip comprises a marking material that makes legible marks on various surfaces. 
     A third embodiment of the present disclosure is a marking device comprising a thin planar plate configured as a razorblade, and a support frame comprising a proximal end and a distal end. The proximal end of the support frame comprises a handle for grasping the support frame, and the distal end comprises a casing having a positioning member. The thin planar plate of the marking device comprises a longitudinally extending marking edge, and at least a portion of the marking edge comprises a marking material that makes legible marks on various surfaces. At least a portion of the thin planar plate comprises one or more alignment structures configured to attach to the positioning member of the casing. 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the various aspects of the invention. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1A  illustrates the front view of a marking device, in accordance with exemplary embodiments of the present disclosure; 
         FIG. 1B  illustrates a side perspective view of the marking device illustrated in  FIG. 1A ; 
         FIGS. 2A-2L  illustrate various exemplary shapes of the marking device depicted in  FIGS. 1A and 1B ; 
         FIGS. 3A-3C  illustrate various possible locations of marking material on a marking device, in accordance with exemplary embodiments of the present disclosure; 
         FIGS. 4A-4C  illustrate various possible configurations of overlays or reinforcement inserts on a marking device, in accordance with exemplary embodiments of the present disclosure; 
         FIGS. 5A and 5B  illustrate marking devices comprising one or more pockets for mounting marking members therein, in accordance with exemplary embodiments of the present disclosure; 
         FIGS. 6A-6D  illustrate various configurations of cut-outs or notches that may be formed on a longitudinal edge of a marking device, in accordance with exemplary embodiments of the present disclosure; 
         FIGS. 7A-7C  illustrate various configurations of cut-outs or notches that may be formed along two edges of a marking device, in accordance with exemplary embodiments of the present disclosure; 
         FIGS. 8A-8C  illustrate various configurations of cut-outs or notches that may be formed in the center of a marking device, in accordance with exemplary embodiments of the present disclosure; 
         FIG. 9  illustrates a marking device mounted on a utility knife, in accordance with exemplary embodiments of the present disclosure; and 
         FIG. 10A  illustrates a snap-off marking blade, in accordance with exemplary embodiments of the present disclosure; and 
         FIG. 10B  illustrates a snap-off marking blade mounted on a snap-off utility knife, in accordance with exemplary embodiments of the present disclosure 
     
    
    
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Reference will now be made to certain embodiments consistent with the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts. 
     In this application, the use of the singular includes the plural unless specifically stated otherwise. Also, the use of “or” means “and/or” unless stated otherwise. Furthermore, the use of the term “including”, as well as other forms, such as “includes” and “included,” is not limiting. The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. 
       FIGS. 1A and 1B  illustrate an exemplary marking device  10  for use in writing or drawing on different materials. Marking device  10  comprises a body  12  configured as a thin plate. Body  12  comprises a first longitudinal edge  14  and a second longitudinal edge  16 , the latter of which is referred to hereinafter as the “marking edge.” In some exemplary embodiments, marking device  10  is shaped as a quadrilateral (i.e., having four sides). The quadrilateral shape of marking device  10  can include, but is not limited to, square, rectangular, or trapezoidal shapes. In select embodiments, the corners of the quadrilateral-shaped marking device  10  are rounded or beveled, as depicted in  FIGS. 2A-2L . In other exemplary embodiments, marking device  10  can have circular, oval, or semi-circular profile. In some embodiments, the shape of marking device  10  can be a combination of a quadrilateral on one side and an oval on the opposite side, as depicted, for instance, in  FIG. 2G ,  FIG. 2J  and  FIG. 2L . 
       FIGS. 2A-2L  illustrates the various exemplary shapes of marking device  10 . The shapes illustrated in  FIGS. 2A-2L  are for representational purpose only, and are not intended to limit the various possible shapes of marking device  10 . 
     In one exemplary embodiment, marking device  10  is shaped as a razorblade and is configured to fit into any standard utility knife. In such an embodiment, marking device  10  can be inserted into a utility knife in place of a regular razorblade. Such an arrangement can reversibly convert an ordinary utility knife into a carpenter pencil. 
     In one exemplary embodiment, marking device  10  has the same thickness throughout body  12 . In another exemplary embodiment, the thickness of marking device  10  tapers gradually from the first longitudinal edge  14  to the marking edge  16 . Marking edge  16  is configured to have a very small thickness in order to make thin, accurate lines. In exemplary embodiments, the thickness of marking edge  16  is in the range of about 0.025″ to about 0.035″. 
     At least a portion of marking device  10  is made of a marking material. The marking material comprises any substance that leaves a mark, stain, or residue on a given surface. The marking material can include, but is not limited to, graphite, chalk, clay, coloring dyes or pigments, day-glow ink, fluorescent ink, etc. The marking material may be a single material, or a composite of two or more marking materials. In exemplary embodiments, one or more marking materials are combined with a reinforcing material to increase the overall strength and/or rigidity of the marking material. In select embodiments, the marking material comprises one or more of a whitening agent, organic coloring pigment, talc filler, thermoset resin and thermoplastic resin. 
     In select embodiments, the entire marking device  10  is made of the marking material. In other embodiments, only marking regions  18  of the marking device include the marking material. For example, marking edge  16 , or a portion thereof, may be made of the marking material, as illustrated in  FIGS. 3A-3C . In such embodiments, the remaining body  12  may be made of a stronger material, such as, metal or plastic, to increase the overall strength, rigidity, or durability of the marking device. Marking regions  18  may be attached to the rest of body  12  with an adhesive or other bonding material. In select embodiments, marking regions  18  are formed using an over-molding process. Prior to over-molding, marking regions  18  are made thinner than the rest of the marking device. Marking device  10  is then inserted into a mold and marking regions  18  are over-molded with the marking material. 
     In certain embodiments, marking device  10  is partially draped or encased with one or more overlays  25  to reinforce the marking device and increase its durability. Overlays  25  may be provided on one or both sides of the marking device. In addition to providing reinforcement, overlays  25  may also be used to print or etch a brand name onto the device. In some exemplary embodiments, a reinforcement insert  26  is embedded within marking device  10 . In such an embodiment, the reinforcement insert may be clad or encased with the marking material to form marking device  10 .  FIGS. 4A-4C  illustrate the various possible configurations of overlays  25  or reinforcement insert  26  on marking device  10 . 
     In some exemplary embodiments, as illustrated in  FIGS. 5A and 5B , marking device  10  comprises a pocket  20  for mounting a marking member  22 . In such embodiments, body  12  of marking device  10 , including pocket  20 , is made of plastic or metal (for example, stainless steel), and the marking member  22  is made of a marking material described earlier in this disclosure. Pocket  20  can be positioned anywhere along marking edge  16 , or at one or more corners of marking device  10 . In one such embodiment, illustrated in  FIG. 5A , pocket  20  comprises an extended flap  23 , which helps to guide the marking member  22  into the pocket. In another embodiment, pocket  20  comprises a spring-loaded tab to firmly secure marking member  22  in the pocket.  FIG. 5B  illustrates marking device  10  with marking member  22  mounted into pocket  20 . In such embodiments, only the marking member  22  has to be replaced when it wears out without having to dispose the entire marking device  10 . In select embodiments, marking member  22  is double edged, i.e., marking member  22  can be flipped around when one edge wears out, and thereby, the marking member can be used longer without requiring a replacement. 
     In illustrative embodiments, marking device  10  is configured to be mounted on a support frame  30 . In some embodiments, edge  14  of the marking device comprises one or more cut-outs, notches, indentations, or alignment tabs configured to connect to corresponding structures or positioning members on support frame  30 .  FIGS. 6A-6D  illustrate various cut-outs/notches  25  formed on edge  14  of the marking device to connect it to support frame  30 . In certain embodiments, cut-outs/notches  25  are formed on both edge  14  and marking edge  16 , as depicted in  FIGS. 7A-7C . In other embodiments, the cut-outs/notches  25  or other alignment features are positioned in the center portion of marking device  10 , as illustrated in  FIGS. 8A-8C . 
     In select embodiments, support frame  30  along with marking device  10  is disposable. In other embodiments, support frame  30  is reusable. In such embodiments, when marking device  10  wears out, it can be swapped with a replacement marking device  10 . 
     In exemplary embodiments, support frame  30  comprises a proximal end  32  and a distal end  34 . Distal end  34  is configured to mount marking device  10 , and the proximal end  32  is configured as a handle that may be gripped by an user while using the marking device. In one embodiment, distal end  34  comprises a safety casing configured to house marking device  10  when not in use. Marking device  10  can be pushed or folded out of the casing when needed to draw or write on a surface. In such embodiments, proximal end  32  may comprise a manual switch (for example, a thumb slider) that triggers an activation mechanism to push or slide marking device  10  out of the safety casing. Alternatively, the switch/trigger for pushing or sliding the marking device out may be positioned anywhere on support frame  30 . When not in use the marking device  10  can be retracted back into the safety casing. For example, marking device  10  may be automatically retracted into the safety casing when the switch/trigger on the proximal end  32  is released. Such an arrangement shields marking device  10  from damage. In another embodiment, distal end  34  is simply configured to fasten marking device  10  without providing a safety casing. Such an embodiment may comprise a removable cap or a guard to shield marking device  10  when not in use. 
     In illustrative embodiments, marking device  10  has the same dimensions as that of a conventional razorblade and is adapted to fit a retractable or folding utility knife (for example, a STANLEY knife). In such embodiments, the utility knife serves as support frame  30 . In select embodiments, marking device  10  is a combination of a conventional razorblade on one side for use in cutting/sculpting, and a marking tool on the opposite side for drawing or writing. The combination blade may be used with the utility knife. 
       FIG. 9  illustrates marking device  10  mounted on a support frame/utility knife  30 . In exemplary embodiments, the razorblade-shaped marking device  10  has an average thickness of about 0.025″ to about 0.035″, length of about 2.425″ and the height ranges from about 0.735″ to about 0.75″. In exemplary embodiments, marking edge  16  is razor-thin, and thus, it allows precise lines to be made on any given surface. In one such embodiment, the thickness of the lines made by marking device  10  is about 0.025″ to about 0.035′. 
     In select embodiments, marking device  10  is in the form of a snap-off razorblade configured to fit a snap-off utility knife  50 .  FIG. 10A  illustrates a snap-off marking device  10 , and  FIG. 10B  illustrates a snap-off marking device  10  mounted on a snap-off utility knife  50 . The blade sections of a snap-off marking device  10  can be broken to release fresh, sharp marking edge  16 . The blade can be retracted for safe storage when not in use. In some embodiments, snap-off marking device  10  is a solid planar blade, i.e., without the snap-off portions, and is configured to be mounted on a snap-off utility blade. 
     By configuring marking device  10  as a razorblade, a utility knife can be converted into a carpenter pencil as and when required. Such an arrangement has several advantages over standard carpenter pencils. For instance, a utility knife is easier to grip than a carpenter pencil, and also, utility knife is a common tool already used by carpenters, builders, contractors, and tradesmen in general. The razorblade of the utility knife can be easily swapped with marking device  10  to generate a carpenter pencil. Once mounted onto a utility knife, marking device  10  is easily protected from damage in the workplace environment, for example, when placed in a bag together with heavy tools. 
     Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.