Abstract:
A handheld tool for engraving concrete, wood, composite or other surfaces using a motor is described. The surface engraver includes an adjustable depth stop, a cutter assembly, and various adjustable guides for controlling the engraving process. The cutter assembly is mounted on a chassis for moving the engraver over the surface during use, and is provided with a means for evacuating particles and other dust and debris created by the engraving process.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority of U.S. provisional patent application Ser. No. 61/416,514, filed Nov. 23, 2010. This application is also a continuation-in-part of U.S. patent application Ser. No. 29/379,035, filed Nov. 12, 2010. The disclosures of aforementioned patent applications are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The surface engraver described herein relates to devices for engraving surfaces of concrete, wood, composite or other materials. More specifically, the surface engraver is in the field of tools for engraving surfaces with decorative and structural grooves and other patterns. 
         [0004]    2. Summary of the Invention 
         [0005]    A surface engraver is described comprising a chassis, having a front member, a rear member and a right side member, with four wheels rotatably mounted at each corner of the chassis and a cutter assembly for supporting a motor with a blade; the cutter assembly is pivotally mounted on the chassis adjacent to the front end of the chassis; the cutter assembly further comprises a blade shield, a handle member, a depth stop assembly, and an actuator for the motor. 
         [0006]    In embodiments of the surface engraver, the blade shield further comprises an exhaust port in a rear surface of the blade shield, and a drive port for a drive shaft of the motor; and the blade shield defines an interior volume substantially shielded on three sides by the blade shield. 
         [0007]    In the described embodiment of the surface engraver, the depth stop assembly comprises a mounting block attached to the blade shield, a depth stop pin adjustably engaged by the mounting block, and a depth stop adjustment knob attached to the depth stop pin. In some embodiments of the surface engraver, the depth stop pin is threaded, and the mounting block is provided with a threaded hole for engaging the threads on the depth stop pin. 
         [0008]    The actuator for the motor comprises an actuator member pivotally attached to the handle member, and the actuator member further comprises a grip member substantially parallel to the handle member and pivotally attached thereto at a first end thereof, an elbow member depending from the grip member adjacent to the pivotal attachment, and a pin extending substantially perpendicularly to the elbow member from the end thereof for engaging an actuator lever on the motor. 
         [0009]    The surface engraver may be provided with a front line guide attached to the front end of the chassis for indicating the line of the blade, and a rear line guide attached to the rear end of the chassis. The surface engraver may also be provided with a plurality of mounting holes provided in the side member, and a front guide and a rear guide attached to the side member by the mounting holes; wherein the front guide indicates the leading cutting edge of the blade and the rear guide indicates the trailing cutting edge of the blade. 
         [0010]    A guide support may be mounted on the chassis adjacent to the front end thereof, with a guide arm, having a first and second end, pivotally attached to the guide support by a first end thereof, a guide wheel rotatably attached to a second end of the guide arm; wherein the guide arm indicates the line of the blade. 
         [0011]    In some embodiments of the surface engraver, a spring is provided between the depth stop mounting block and the chassis for pivoting the cutter assembly away from the chassis when not in use. An exhaust pipe may also be provided for directing debris through the exhaust port on the blade shield. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a perspective view of an embodiment of the surface engraver. 
           [0013]      FIG. 1A  is an exploded perspective view of an embodiment of the surface engraver. 
           [0014]      FIG. 2  is a right side view of an embodiment of the surface engraver. 
           [0015]      FIG. 3  is a left side view of an embodiment of the surface engraver. 
           [0016]      FIG. 4  is a top plan view of an embodiment of the surface engraver. 
           [0017]      FIG. 5  is a bottom plan view of an embodiment of the surface engraver. 
           [0018]      FIG. 6  is a rear plan view of an embodiment of the surface engraver. 
           [0019]      FIG. 7  is a front plan view of an embodiment of the surface engraver. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The surface engraver is an improved and inventive tool for engraving the surface of concrete, wood, composite or other materials to provide decorative and functional scoring or grooving of the surfaces. The surface engraver is a convenient and economical handheld tool for precisely and consistently engraving such surfaces. The surface engraver may utilize commonly available pneumatic, electric or hydraulic motor to engrave the surface, and allows a user to control the motor with ease and precision. 
         [0021]    Referring now to  FIG. 1 , a perspective view of an embodiment of the surface engraver is depicted. The chassis  100  provides a support frame on which the other components of the surface engraver are attached. In the embodiment shown in the figures, the chassis comprises a front member extending across the front end of the engraver, a rear member extending across the rear end of the engraver, and a right side member connecting the front and rear members of the chassis. In other embodiments of the chassis there may be more members, such as a left side member without departing from the spirit of the invention. 
         [0022]    The chassis  100  is mounted on wheels  102 , which may be formed from machined or cast metal and provided with tires  104  formed from rubber, plastic or some other similar suitable material. The wheels  102  may be rotatably mounted on bolts that engage threaded mounting holes on chassis  100 , or wheels  102  may be mounted on an axle that extend through the width of chassis  100  and are rotatably supported therein. 
         [0023]    Chassis  100  may be machined or cast from metal or other material of appropriate strength and hardness. Although the chassis may be cast or machined from various materials, in some embodiments the chassis is machined from a metal such as aluminum. Alternatively it may be formed from components attached to each other by means of welding, bolts or other means of attachment. 
         [0024]    A cutter assembly  106  is attached to the chassis  100 . The cutter assembly  106  provides the support and control mechanism for controlling the motor  108  attached to the surface engraver. The motor  108  incorporates a blade  110  that is located inside the cutter assembly  106  when in use. Motor  108  and blade  110  are depicted in a later figure. 
         [0025]    The cutter assembly  106  is pivotally attached to the chassis  100  at a point near the front end  112  of the chassis  100  to allow the motor  108  to be raised and lowered to control contact between the blade  110  and the surface. As will be described below, the cutter assembly  106  incorporates components to control the depth of the engraving, to actuate the motor, and to control the particulate matter that is released by the blade. 
         [0026]    A guide support  114  is also attached to chassis  100  adjacent to the front end  112  of the chassis  100 . A guide arm  116  is pivotally attached at a first end thereof to the guide support  114  by means of a fastener  118 . The fastener  118  may be a nut and bolt combination or some other commonly used fastener for secure pivotal attachment. The guide support  114  may be provided with a plurality of mounting holes  120  for attaching the guide arm  116  to the guide support  114  at different spots as necessary. Guide support  114  also provides a mechanical stop to limit the rotation of cutter assembly  106 . 
         [0027]    Guide wheel  122  is attached adjacent to the second end of guide arm  116  and may freely rotate about the point of attachment. In the embodiment shown in the figures, guide wheel  122  is attached to a shaft  124 , which is attached to a mounting hole in guide arm  116 . In other embodiments, other means of attaching guide wheel  122  to guide arm  116  may be utilized. 
         [0028]    The guide wheel  122  is disposed in line with blade  110  to provide the user with an external point of reference regarding the location of the blade  110  during operation of the engraver. When the guide wheel  122  is not needed for or would interfere with operation of the engraver, guide arm  116  may be pivoted around fastener  118  up and into a retracted position. The figures depict guide arm  116  in an extended position. 
         [0029]    Cutter assembly  106  is pivotally attached to the chassis  100  adjacent to the first end  112  thereof. The cutter assembly comprises a blade shield  126  for blocking material ejected by the blade  110  and preventing unintended contact between the blade  110  and the user. In embodiments the blade shield may be formed from metal such as aluminum, but other metals or non-metal materials of appropriate strength and hardness may be utilized as well. The blade shield  126  may be machined or cast as a solid piece of material, or may be formed from various components attached together with welds, bolts, or other similar methods of fastening. In the embodiment shown in the figures, the right side of blade shield  126  is attached by means of a plurality of bolts and may be removed as necessary to access blade  110 . 
         [0030]    The blade shield  126  may have a handle member  128  attached to or incorporated into it for the user of the surface engraver during operation. The handle member  128  may also incorporate a means of actuating the motor  108 , as will be described in relation to a later figure. 
         [0031]    In embodiments of the surface engraver, a depth stop assembly  130  may be attached to the cutter assembly  106 . The depth stop assembly  130  provides the user of the surface engraver with a device for controlling the depth of the cut made by the blade  110  when the user actuates the motor  108  and depresses the cutter assembly  106 . 
         [0032]    In the embodiment shown in the figures, the depth stop assembly comprises a mounting block  132 , a depth adjustment knob  134  and a depth stop pin  136 . The depth stop pin  136  may be translated up and down within mounting block  132  by turning depth adjustment knob  134 . In the embodiment shown in the figures, user rotation of depth adjustment knob  134  causes pin  136  to translate up and down through mounting block  132  by means of threads on the pin and mounting block  132 . Other methods of securing, releasing and adjusting depth stop pin  136  may be utilized by other embodiments of the engraver. 
         [0033]    During use of the engraver, the bottom end of pin  136  contacts a portion of chassis  100  comprising a depth stop pad  140  and prevents cutter assembly  106  from pivoting further down and thus prevents blade  110  from cutting further into the surface being engraved than desired by the user. 
         [0034]    A spring  138  may also be provided between mounting block  132  and pad  140  on chassis  100 . The spring  138  forces cutter assembly  106  and chassis  100  apart and maintains blade  110  above the surface to be engraved until the user depresses the cutter assembly  106  by means of handle member  128  to overcome the force of spring  138 . 
         [0035]    A front line guide  142  is attached to chassis  100  on the front end  112  thereof. Front line guide  142  is aligned with the blade  110  and provides an external point of reference for the axis of the blade  110  as it is rolled on tires  104 . Front line guide  142  may be attached to chassis  100  by screws, bolts or other commonly known methods of attachment. In the embodiment shown in the figures, the mounting holes in guide  182  for receiving bolts  184  may be slotted to allow the guide  182  to be adjusted for the thickness of blade  110 . 
         [0036]    Referring now to  FIG. 1A , an exploded perspective view of an embodiment of the surface engraver is depicted. The grinder assembly can be seen removed from chassis  100 . Mounting holes are provided in chassis  100  for accepting mounting bolts to secure the grinder assembly  106  to chassis  100  and allow it to pivot. In embodiments the mounting holes are threaded. In the embodiment shown in  FIG. 1A  the mounting bolts comprise set screws with conical ends. The set screws engage the threaded mounting holes and are disposed therein with the conical ends extending into holes or indentations provided in the grinder assembly  106 . In other embodiments the mounting bolts may be common bolts, and bushings, bearings or other common methods of providing pivotal attachment may be utilized in place of conical ends on the bolts to engage the grinder assembly. 
         [0037]    A portion of grinder shield  126  is shown removed from the other portions of the grinder shield  126  which are a unitary part of grinder assembly  106 . The bolt or screw used to secure guide support  114  in mounting groove  190  is clearly depicted as removed from mounting hole  188 . 
         [0038]    Referring now to  FIG. 2 , a right side view of an embodiment of the surface engraver is depicted. As described in relation to  FIG. 1 , the chassis  100  is supported by wheels  102  and tires  104 . Cutter assembly  106  is pivotally attached to chassis  100  at a front end of assembly  106 . Guide support  114  extends upwardly from chassis  100  adjacent to the front end of the chassis  100 . Guide arm  116  is pivotally attached to guide support  114  at a first end thereof by a fastener  118 . Guide arm  116  is depicted in  FIG. 2  in a slightly raised position, with blade  122  above the location of the surface to be engraved. 
         [0039]    Depth stop assembly  130  is attached to cutter assembly  106  as described in relation to  FIG. 1 . In the embodiment shown in the figures, bolts  144  are provided to adjustably attach mounting block  132  to cutter assembly  106 . 
         [0040]    Cutter assembly  106  is provided with an exhaust port  146  in the rear surface thereof, for guiding particulate matter, dust and debris out of the area of the blade  110 . An exhaust pipe  148  may be provided to guide the debris from port  146  away from the engraver and the user of the engraver, or may be coupled to a vacuum hose attached to a debris containment system. In the embodiment shown in the figures, exhaust pipe  148  transitions from a circular cross-section near the outward end thereof to a rectangular cross-section at its interface with exhaust port  146  by means of parabolic surfaces  150 . In other embodiments of the engraver, the exhaust pipe may be of uniform elliptical, rectangular or any other cross-section, or may have elbows, bends or curves as desired. The exact shape and configuration of exhaust pipe  148  is not limiting of the surface engraver described herein. 
         [0041]    Referring now to  FIG. 3 , a left side view of an embodiment of the surface engraver is depicted. Motor  108  is attached to the left side of blade shield  126 . The motor  108  shown in the figures is in the form of a pneumatic angle grinder, though this is not limiting of the invention. In the optional configuration shown in the figure, the handle area of the motor  108  extends upwardly and along the side of cutter assembly  106 . In the embodiment the motor  108  incorporates an angle drive mechanism  152  which is releasably attached to blade shield  126  by bolts attached to mounting holes  154 . The configuration of holes  154  may vary as needed to match mounting holes provided on motor  108 . The drive shaft of motor  108  extends through drive port  156  into the interior volume of blade shield  126 . Blade  110  is disposed on the end of drive shaft  156  inside shield  126 . 
         [0042]    The motor actuation mechanism incorporated in the engraver is more clearly depicted in this figure. Various manufacturers provide varying means of actuating their motors  108 , and the actuation mechanism provided in an embodiment of the engraver may vary as necessary to engage the motor  108 . In some embodiments, the actuation mechanism may mechanically actuate motor  108  and in others it may electrically, hydraulically or pneumatically actuate motor  108 . 
         [0043]    In many motors  108 , actuation is accomplished by means of a lever  158  attached to the handle of the motor  108 . When lever  158  is depressed the motor actuates, and engages the drive motor thus spinning the blade  110 . The figures depict an embodiment of the engraver for engaging this type of motor actuator. In other embodiments of the surface engraver, differing motor actuation mechanisms may be provided for actuating motors with other means of actuation. 
         [0044]    In the embodiment shown in the figures, actuator  160  is pivotally attached to handle  128 . The actuator  160  comprises a grip area  162  and elbow  164  extending at right angles to one another from a point near pivot point  166 . The actuator  160  is pivotally mounted to handle  126  at pivot point  166  by means of a fastener  168  such as a bolt. A pin  170  extends outward from elbow  164  and engages actuation lever  158  on motor  108 . 
         [0045]    During operation of the engraver, a user grips handle  128  with her fingers extending underneath grip  162 . When the user desires to being engraving, the user squeezes the grip  162  against handle  128 , thus pivoting actuator  160  around pivot point  166  and causing pin  170  to depress actuator lever  158 . When lever  158  is sufficiently depressed it actuates the motor  108  and initiates grinding by blade  110 . 
         [0046]    Referring now to  FIG. 4 , a top plan view of an embodiment of the surface engraver is depicted. The open-sided design of chassis  100  can clearly be seen in this figure, as there is a side member  174  on the right side of chassis  100 , but no side member on the left side of chassis  100 . 
         [0047]    Front guide  176  and rear guide  178  are provided on side member  174  to provide the user of the surface engraver with a visual reference to the front and back cutting edges of the blade  110 . Guides  176  and  178  allow the user of the surface engraver to begin and end cuts with precision. Guides  176  and  178  are mounted on side member  174  by bolts  180  which engage threads in mounting holes  172  in side member  174 . Multiple mounting holes  172  may be provided to allow the guides  176  and  178  to be adjusted for differing diameters of blades  110 . The mounting holes provided in guides  176  and  178  may be slotted to allow the position of the guides to be adjusted for changes in the diameter of blade  110  due to wear. 
         [0048]    Referring now to  FIG. 5 , a bottom plan view of an embodiment of the surface engraver is provided. A rear line guide  182  is attached to the rear of chassis  100  by bolts  184  in line with blade  110 . The mounting holes in guide  182  for receiving bolts  184  may be slotted to allow the guide  182  to be adjusted for the thickness of blade  110 . The opening  186  in the bottom of blade shield  126  allows blade  110  to extend below the blade shield  126 . 
         [0049]    Referring now to  FIGS. 6 and 7  respectively, a rear plan view and a front plan view of an embodiment of the surface engraver is depicted. The groove  190  adjacent to the front end of chassis  100  provides an alternative mounting location for guide support  114 . The mounting hole  188  provides a means of attaching support  114  in groove  190 . The bolt holding support  114  in its depicted position may be removed and the support  114  moved over to the groove  190 , and the bolt replaced in its position. Arm  116  can then be removed and mounted on the opposite side of support  114  if necessary. Similarly shaft  124  may be removed from arm  116  and flipped horizontally to keep guide  122  in line with blade  110 . 
         [0050]    Many different arrangements of the various components depicted, as well as components not shown, are possible without departing from the spirit and scope of the present invention. Embodiments of the present invention have been described with the intent to be illustrative rather than restrictive. Alternative embodiments will become apparent to those skilled in the art that do not depart from its scope. A skilled artisan may develop alternative means of implementing the aforementioned improvements without departing from the scope of the present invention. 
         [0051]    It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated within the scope of the claims. Not all steps listed in the various figures need be carried out in the specific order described.