High-speed, hand-held reciprocating method for cutting, carving, sawing, chiseling, filing, sanding, and engraving

[0002] This application is entitled to the benefit of Provisional Patent Application No. 60/318,895, filed Sep. 13, 2001.

[0003] 1. Field of Invention

[0004] This present invention relates to hand-held tools, specifically to a hand-held reciprocating attachment for power rotary tools.

[0005] 2. Discussion of Prior Art

[0006] Power-driven hand-held rotary tools and reciprocating tools are known to exist in prior art. Such tools currently available exhibit problems in regards to delicate, detail work.

[0007] Rotary tools rotate tool attachments, such as ball grinders, sanding discs and drums, and cutting wheels, at a variable RPM up to very high RPM. Although such rotary tools are very useful in numerous applications they do have limitations. When trying to perform detailed shaping or precise removal of material from a work piece with a hand-held rotating tool, a ball grinder, sanding disc or drum, or cutting wheel attachment can grab a material and cause a tool to be pulled in an unwanted direction thereby blemishing or even destroying a work piece. For one example of a professional application, this potentially damaging scenario is a real concern when modifying or repairing very expensive electronic printed circuit board assemblies. It is common practice to use either a manual razor knife or a rotary tool with a small cutting ball to sever small clad runs on electronic printed circuit boards where a connection needs to be broken. When the operator loses control of a rotary cutting tool due to grabbing numerous unwanted clad traces can be severed, sometimes in an un-repairable area of the board, resulting in hundreds or thousands of dollars in wasted inventory. Also, using a manual hobby razor knife in such as application requires quite a bit of force that can promote slipping and loss of control. Cutting with a rotary tool is limited to the use of a spinning, abrasive cutting wheel, and gaining access to a desired area of a work piece at a desired cutting angle is sometimes impossible to achieve. This is because rotary cutting tools have a limitation in that some of the parts comprising the drive mechanism of the cutting wheel are either above, below, to the right, or to the left of the plane of the cutting wheel depending on orientation. Carving with a hand-held rotary tool requires the use of a spinning, course-cutting attachment that, too, can catch on a material, cause a tool to be pulled in an unwanted direction, and cause damage to a work piece. Sawing with a hand-held rotary tool is limited to the use of a spinning, abrasive cutting wheel, or a round saw with teeth, and gaining access to a desired area of a work piece at a desired cutting angle is sometimes impossible to achieve. Also, the depth of cut realized with a cutting wheel or round saw is limited to slightly less than its radius. Chiseling with a hand-held rotary tool using only rotating motion is potentially dangerous because it requires a rotating bit containing cutting blades that is difficult to control and certainly not suited for fine, detail work. Filing with a hand-held rotary tool is limited to a use of a spinning, abrasive cutting wheel or a spinning abrasive bit. Gaining access to a desired area of a work piece at a desired angle with an abrasive wheel for filing is sometimes impossible to achieve, and filing with a spinning abrasive bit can cause unwanted variable-depth cuts, or unwanted grooves, in a work surface. Sanding with a hand-held rotary tool requires a spinning sanding disc or a sanding drum attachment that can grab a material, cause a tool to be pulled in an unwanted direction, and either cause damage to or destroy a work piece.

[0008] Some available hand-held reciprocating tools are too large and too heavy to hold properly for extreme detail work because they include an AC motor or a DC motor with batteries. Also, they are more dedicated to certain applications, such as just sanding or just carving, and don't allow for an assortment of tool attachment types. Some do not hold tool attachments firmly enough for extremely fine control of a tool attachment.

[0009] Reciprocating carving tools that don't activate until the cutting edge is pressed against the work piece with a force parallel to the longitudinal axis are not suited for knife blades, saw blades, files, and sanders because such tool attachments require pressure to be applied perpendicular to the tool's longitudinal axis. Therefore, force-activated tools are typically limited to chisels and gouges and are not suited for delicate work because the required force to active may exceed the mechanical strength of the work piece.

[0010] Hammer-type reciprocating tools impart a potentially damaging impulse to delicate work pieces. Also, the impact and spring return mechanisms do not have a high frequency response. They do not allow for a fine degree of force control required for delicate work pieces.

[0011] Engravers are reciprocating tools, but they are limited in their ability to provide a variable-speed, variable-length stroke. They also are not suited for the use of other types of cutting tools and are dedicated to engraving only.

[0012] A reciprocating hand tool for flexible shafts in U.S. Pat. No. 1,866,529 to Farkas, is provided for general reference. The referenced inclined annular groove will result in large acceleration and deceleration forces between the annular groove and the ball and socket set screw.

[0013] A solenoid-powered surgical osteotome in U.S. Pat. No. 2,984,241 to Carlson, is in a different technical field as compared to the invention claimed in this application.

[0014] A saber saw attachment in U.S. Pat. No. 3,260,289 to Whitten, claims a saber saw attachment, to the exclusion of other types of cutting tools.

[0015] A reciprocating chisel blade power hoe in U.S. Pat. No. 4,452,316 to Edwards, is in a different technical field as compared to the invention claimed in this application.

[0016] A reciprocating knife in U.S. Pat. No. 4,644,653 to Bacon, Feb. 24, 1987, claimed a reciprocating knife tool, to the exclusion of other types of tools. Additionally, the invention claimed the use of two opposed elastic members for biasing, which has a limited frequency response, and screws to affix a cutting blade section to a blade, which can loosen due to vibration and which require additional tools for assembly.

[0017] A power operated reciprocating hand tool in U.S. Pat. No. 4,727,941 to Fulton, Feb. 24, 1986, claimed a flexible sleeve and utilized a flexible reciprocating cable, coil spring, and mallot that applied a fixed impact force to a cutting tool that limits its applications. Furthermore, a spring's response limited the attainable reciprocating frequency.

[0018] A power tool in U.S. Pat. No. 5,042,592 to Fisher, Aug. 27, 1991, was designed for heavier-duty home project applications such as paint scraper and a wallpaper stripper, as opposed to highly detailed and/or more delicate applications, and claims a sinusoidal cam track and cam follower mechanism with a pair of struts, and intermediate gearing interposed between the drive mechanism and the output shaft. Furthermore, this is in a different technical field as compared to the invention claimed in this application.

[0019] A power tool in U.S. Pat. No. 5,513,709 to Fisher, May 7, 1996, was designed for heavier-duty home project applications such as paint scraper and a power spade, as opposed to highly detailed and/or more delicate applications, and claims a sinusoidal cam track and cam follower mechanism with at least two studs, struts, or bosses, and intermediate gearing interposed between the drive mechanism and the output shaft. Furthermore, this is in a different technical field as compared to the invention claimed in this application

[0020] The reciprocating attachment for hand drills in U.S. Pat. No. 5,607,265 to Lane, Mar. 4, 1997, is designed to work only with saw blades while being powered by a lower-RPM hand drill. Furthermore, the saw blade is attached with screws that are subject to loosening under vibration and the saw blade mounting method requires that either special, non-standard saw blades be purchased by the consumer or requires that the consumer modify existing saw blades for adequate mounting.

[0021] The power drill-saw with simultaneous rotation and reciprocation action in U.S. Pat. No. 5,676,497 to Kim, Oct. 14, 1997, claims a cam key and a cam groove with an elliptical orbit about a cam cylinder. The elliptical orbit will result in large acceleration and deceleration forces between the cam groove and the cam key resulting in excessive wear.

[0022] The electric oscillating abrasive file in U.S. Pat. No. 5,759,093 to Rodriguez, Jun. 2, 1998, claimed an electric abrasive file, to the exclusion of other types of tools, and included a U-shaped spring clip to hold a file tool that had limited resistance to applied forces.

[0023] A variable angle reciprocating tool in U.S. Pat. No. 5,832,611 to Schmitz, Nov. 10, 1998, claimed a motor housing and motor and is bulky and heavy, which is a negative in regards to fine detail work.

[0024] A low vibration motion translation system in U.S. Pat. No. 6,012,346 to Vo, Jan. 11, 2000, claims a low vibration motion translation system but it neither provides a detailed solution for affixing an outside housing, which would thereby make a hand-held device for an end user, nor does it provide detailed solutions for easily affixing various tools to the reciprocating piece.

[0025] A motorized reciprocating surgical file apparatus and method in U.S. Pat. No. 6,048,345 to Berke, Apr. 11, 2000, is in a different technical field as compared to the invention claimed in this application.

[0026] A miniature impact tool in U.S. Pat. No. 6,085,850 to Phillips, Jul. 11, 2000, is primarily used to impact a cutting tool (chisel) against a work piece. It utilizes a spring in its design and therefore its frequency response is limited. Furthermore, its hammer-type action could impart a potentially damaging impulse to delicate work pieces

[0027] A reciprocating apparatus and cam follower for winding a package in U.S. Pat. No. 6,119,973 to Galloway, Sep. 19, 2000, is in a different technical field as compared to the invention claimed in this application. Furthermore, a reciprocating apparatus and cam follower for winding a package claimed a strand guide intended for glass strands.

[0028] A variable angle reciprocating tool in U.S. Pat. No. 6,138,364 to Schmitz, Oct. 31, 2000, employed multiple gears and multiple bearings which make the assembly more complex and therefore more prone to mechanical problems.

[0029] Powered surgical handpiece assemblies and handpiece adapter assemblies in U.S. Pat. No. 6,368,324 B1 to Dinger et al, Apr. 9, 2002, is in a different technical field as compared to the invention claimed in this application. Furthermore, front housing and rear housing are multiplied piece assemblies as opposed to much simplified one-piece front enclosure and one-piece rear enclosure of the invention claimed in this application. Also, the suction tube is not required for the invention claimed in this application.

[0030] No prior art directly germane to this invention was found which anticipates the inventive combination disclosed below. Furthermore, I am very familiar with both the hobby industry and the tool industry and have never seen anything like my hand-held, reciprocating attachment promoted for sale.

[0031] A high-speed, hand-held reciprocating method for cutting, carving, sawing, chiseling, filing, sanding, and engraving of the subject invention provides for greatly improved ease in cutting, carving, sawing, chiseling, filing, sanding, and engraving in a multitude of applications. My hand-held, reciprocating attachment allows for more delicate control of a desired operation by reducing the amount of required force applied to a work piece while reciprocating a cutting tool at a high-frequency to minimize the process time. By reducing the required amount of force applied to a work piece, safety of a user is enhanced, fine control over material removal is enhanced, and the chance of damage to a work piece is reduced. A preferred embodiment is described herein but in no way is intended to limit the design details of the subject invention. Applications include, but are not limited to, odd jobs, home repair jobs, arts and crafts, hobby projects, sculpture, electronic printed-circuit board rework, mat cutting for picture frames, and professional model building.

[0032] Accordingly, several objects and advantages of my hand-held, reciprocating attachment are that it is compact and easy to hold and manipulate in your hand and fingertips for very precise work. It is held in one's hand more like a small hobby knife rather than like a more bulky power tool and is therefore very comfortable to use. It is capable of accepting a wide assortment of flat and round cutting tools such as knife blades, saw blades, carving blades, chisels, gouges, round and flat files, and sanding paddles. As an attachment, it converts popular, commercially available, variable-speed rotor tools into even more versatile variable-speed reciprocating tools. One example of such a rotor tool is a DREMEL® tool and optional flex rotor shaft, manufactured by, and a registered trademark of, DREMEL of Racine, Wisc., which is the subject of the preferred embodiment. My hand-held reciprocating attachment can be altered to conform to other rotor tools. Installation onto an end of a rotating flex cable drive source is quick and easy. No assembly tools are required to assemble my hand-held reciprocating attachment nor to install it onto a flex cable nor to install any of a plurality of cutting tools. It is very user-friendly and allows a user to make quick changes in cutting tools. My hand-held, reciprocating attachment is capable of running at very high reciprocating frequencies, being limited mainly by the rotating drive source. Loss of control of a spinning rotary cutting tool, and subsequent damage to the work piece, is eliminated with this current invention.

[0033] Rotary cutting wheels and rotary saw blades have a limitation in that the depth of any cut cannot exceed their radius due to the interfering axial drive. Unlike rotary cutting wheels and rotary saw blades that have parts above or below the plane of the wheel, my hand-held, reciprocating attachment, with its reciprocating cutting tool being on the assembly's extremity with no interfering pieces, allows deep, perpendicular cuts, as well as cuts at any angle, in cramped spaces.

[0034] My hand-held, reciprocating attachment is also capable of being used as an engraver. By installing the proper hardened point tool the variable-speed, variable-stroke reciprocating attachment accommodates finely controlled engraving.

[0035] My hand-held, reciprocating attachment is comprising of a minimum of pieces. Accordingly, my hand-held, reciprocating attachment is very reliable. My hand-held, reciprocating attachment eliminates the need for gears, springs, elastic members, and clips, thereby saving cost and complexity and improving overall reliability. Not using springs in my hand-held reciprocating attachment allows for improved frequency response at the higher reciprocating frequencies. No use of gears allows for improved wear by eliminating more wear surfaces and minimizing potential mechanical problems. Using tool holder/collets instead of clips results in improved, more positive holding force for the cutting tools and accommodates both flat and round cutting tools allowing a wide array of tool selection.

[0036] Other objects and advantages are illustrated as follows. Using razor knives, wood carving blades, saw blades, gouges, chisels, files and sanding paddles mounted in handles for holding in one's hand without the aid of mechanical power, in other words, manual tools, is very common in both professional and hobby-related model building, all types of arts and crafts, and in all types of odd-jobs. The need to place excessive pressure on a cutting edge for some applications is dangerous and can injure a user if the cutting edge slips, and can also be damaging to the work piece. Also excessive pressure on a cutting edge can reduce accuracy. Also, numerous strokes are quite often required, at the expense of time and energy, to cut through material or to remove a desired amount of material. This leads to user fatigue and loss of accuracy. The lesser the amount of force that is used in the operation, in the interest of improving safety and minimizing damage, the greater the number of strokes that are required to achieve the desired results. A greater number of strokes, again, leads to user fatigue and loss of accuracy.

[0037] My high-speed, hand-held reciprocating method for cutting, carving, sawing, chiseling, filing, sanding, and engraving of the subject invention imparts a very high-speed reciprocating motion to a cutting or carving blade, gouge, saw, chisel, file or sanding device. This in turn allows a user to apply a cutting edge accurately while using significantly reduced force thereby greatly reducing fatigue, improving delicate control, and reducing the chance of damage or injury to both the user and the work piece. A reduced force applied to the cutting tool, compensated for by a variable speed, up to a very high-speed, reciprocating motion, in concert with a very short but variable-length stroke, provides exceptional results.

[0038] My hand-held, reciprocating attachment is not a force-activated device and therefore accommodates a multiplicity of reciprocating cutting tools, not just chisel-like cutting tools. Since it is not a force-activated device, my hand-held, reciprocating attachment is very useful for delicate and highly detailed work because a force does not need to be applied before the cutting action starts. Since, my hand-held, reciprocating attachment does not require force-activation, it will function even with feather-light applied forces and will therefore not overwhelm delicate work pieces.

[0039] Variations of my hand-held, reciprocating attachment will allow attachment directly to a power rotary tool instead of to a flex rotor shaft for users so inclined.

[0040] Further objects and advantages of my hand-held, reciprocating attachment will become apparent from a consideration of the drawings and ensuing description.

[0041] Description of Drawings

[0042] FIG. 1 shows a perspective view with flex rotor shaft and power rotary tool

[0043] FIG. 2 shows an exploded view

[0044] FIG. 3A shows an end view of a one-piece enclosure

[0045] FIG. 3B shows a side view of a one-piece enclosure

[0046] FIG. 4A shows an end view of a rear one-piece enclosure

[0047] FIG. 4B shows a side view of a rear one-piece enclosure

[0048] FIG. 5A shows an end view of a rotating piece

[0049] FIG. 5B shows a side view of a rotating piece

[0050] FIG. 6A shows an end view of a reciprocating piece

[0051] FIG. 6B shows a side view of a reciprocating piece

[0052] FIG. 7A shows a rear one-piece enclosure and flex rotor shaft installation view

[0053] FIG. 7B shows a rotating piece and flex rotor shaft installation view

[0054] FIG. 8 shows a bearing installation view

[0055] FIG. 9 shows a reciprocating piece installation view

[0056] FIG. 10A shows engagement of cam and cam follower

[0057] FIG. 10B shows engagement of rotating piece and cylindrical single row radial bearing

[0058] FIG. 11A shows engagement of rear one-piece enclosure and front one-piece enclosure

[0059] FIG. 11B shows securing the assembly with a thumbscrew

[0060] FIG. 12A shows examples of cutting blades

[0061] FIG. 12B shows examples of carving blades

[0062] FIG. 12C shows examples of gouges

[0063] FIG. 12D shows examples of saw blades

[0064] FIG. 12E shows examples of chisels

[0065] FIG. 12F shows examples of files

[0066] FIG. 12G shows examples of sanding devices

[0067] FIG. 12H shows example of an engraver

[0068] FIG. 13A shows a reciprocating piece terminated with male threads

[0069] FIG. 13B shows a reciprocating piece terminated with an integrated tool holder

[0070] FIG. 13C shows a reciprocating piece terminated with larger female threads

[0071] FIG. 14A shows one alternative example of rear one-piece enclosure for direct attachment to power rotary tool

[0072] FIG. 14B shows one alternative example of rear one-piece enclosure for direct attachment to a different style of power rotary tool

[0073] FIG. 15 shows alternative perspective view with power rotary tool and no flex rotor shaft

[0074] FIG. 16 shows one alternative example of rotor with shaft for mounting in chucks and collets

[0075] A high-speed, hand-held reciprocating method for cutting, carving, sawing, chiseling, filing, sanding, and engraving of the subject invention provides for greatly improved ease in cutting, carving, sawing, chiseling, filing, sanding, and engraving in a multitude of applications. A preferred embodiment is described herein but in no way is intended to limit design details, size, materials, finish, or methods of manufacturing, of the subject invention. FIG. 1 shows a perspective of the preferred embodiment. FIG. 2 shows an exploded view of the preferred embodiment. My hand-held, reciprocating attachment comprises one assembly that includes a machined, front one-piece enclosure 20, FIG. 3A and FIG. 3B, a machined, one-piece rear one-piece enclosure 30, FIG. 4A and FIG. 4B, a machined, one-piece rotatively driven rotating piece 40 with an integral cam groove, FIG. 5A and FIG. 5B, a machined, one-piece reciprocating piece 50 with an integral cam follower and an attachment point for a tool holder or collet, FIG. 6A and FIG. 6B, a commercially obtained bearing 22, FIG. 2, a commercially obtained tool holder or collet 52 for a plurality of cutting blades, a plurality of carving blades, a plurality of gouges, a plurality of saw blades, a plurality of chisels, a plurality of filing devices, and a plurality of sanding devices, FIG. 2, a commercially obtained thumbscrew 32, FIG. 2, and commercially obtained cutting blades 54A, FIG. 12A, carving blades 54B, FIG. 12B, gouges 54C, FIG. 12C, saw blades 54D, FIG. 12D, chisels 54E, FIG. 12E, files 54F, FIG. 12F, sanding devices 54G, FIG. 12G, and an engraving device 54H, FIG. 12H. Items 54A through 54H are examples only and do not represent all of the possible combinations. Front one-piece enclosure 20 and rear one-piece enclosure 30 are made to mate together to enclose and accurately hold rotating piece 40, bearing 22, and reciprocating piece 50 in their proper, respective positions relative to each other while allowing adequate freedom of movement of the respective internal pieces. Front one-piece enclosure 20 and rear one-piece enclosure 30 are sized to promote comfort of holding and gripping my hand-held, reciprocating attachment comfortably in one's hand for use. A preferred embodiment of front one-piece enclosure 20 includes a knurled area around its minor circumference, the barrel-like portion, to promote a more secure and safer grip by an operator's fingers while allowing the assembly to rest over the top of the operator's hand. A preferred embodiment of rear one-piece enclosure 30 includes a knurled area around its circumference to facilitate tightening during assembly to or loosening during disassembly from front one-piece enclosure 20. Rotating piece 40 is rotatively driven via mechanical connection of one end to an externally supplied, commercially available flex rotor shaft 34. Another end of rotating piece 40 is supported by high-speed bearing 22 mounted inside front one-piece enclosure 20. Reciprocating piece 50 is held in place adjacent to rotating piece 40 by front one-piece enclosure 20 such that the cam follower portion of reciprocating piece 50 rests inside the cam groove of rotating piece 40. As rotating piece 40 is rotatively driven reciprocating piece 50 is allowed to freely translate along its longitudinal axis via cam action through a maximum distance determined by the particular rotating piece 40 installed at that time. In a preferred embodiment cross-sectional diameters of reciprocating piece 50 and rotating piece 40 overlap. However, a portion of reciprocating piece 50 on the same side as the cam follower of reciprocating piece 50 in aposition to rotating piece 40 is relieved just enough to provide clearance from the main body of rotating piece 40 and the relief is curved around a portion of the main body of rotating piece 40 so as to prevent rotation of reciprocating piece 50 which, in turn, prevents disengagement of the cam follower on reciprocating piece 50 from the cam groove on rotating piece 40. A cam groove offset of rotating piece 40 is variable from piece to piece at time of manufacture to suit a particular application. Rear one-piece enclosure 30 encloses one end of an externally supplied flex rotor shaft 34. Rear one-piece enclosure 30 allows for installation of thumbscrew 32 through its side to firmly captivate it in relation to an externally supplied flex rotor shaft 34. With all pieces in place, after rear one-piece enclosure 30 and front one-piece enclosure 20 have been properly mated, the assembly is firmly captivated to an end of flex rotor shaft 34 using thumbscrew 32. An opposite end, the outside end, of reciprocating piece 50 extends past the smaller-diameter end of front one-piece enclosure 20 even at its rearmost point of travel. In a preferred embodiment the outside end of reciprocating piece 50 is threaded to accept a commercially available tool holder or collet 52 for cutting blades, carving blades, gouges, saw blades, chisels, files, and sanding devices. Rear one-piece enclosure 30 encloses a portion of a handgrip on the end of an externally supplied flex rotor shaft 34. Rear one-piece enclosure 30 allows for installation of thumbscrew 32 through its side. With all pieces in place, after rear one-piece enclosure 30 and front one-piece enclosure 20 have been properly mated, an assembly of the subject invention is firmly captivated to the end of flex shaft 34 using thumbscrew 32.

[0076] The description contained herein is based on the preferred embodiment and assumes that no pieces of the assembly have previously been connected to each other. To prepare the high-speed, hand-held reciprocating attachment for use it must be assembled onto an externally provided, commercially available flex rotor shaft of a DREMEL® rotor tool. Referring to FIG. 7A, one first slips rear one-piece enclosure 30 over the end of the externally supplied flex rotor shaft 34 of the commercially available rotor tool, not shown, making sure that rear one-piece enclosure 30 is oriented such that the large, male threads of rear one-piece enclosure 30 are placed over the end of the flex rotor shaft last. Next, referring to FIG. 7B, rotating piece 40 is attached to the externally supplied flex rotor shaft 34 of the commercially available flex rotor tool, not shown, by threading rotating piece 40, having female threads, onto flex rotor shaft 34, having male threads. Next, as illustrated in FIG. 8, reciprocating piece 50 is partially inserted into front one-piece enclosure 20, oriented such that the female-threaded end of reciprocating piece 50 is in the barrel-like portion of front one-piece enclosure 20 and leaving the other, cam-follower end of reciprocating piece 50 extending out past the large end of front one-piece enclosure 20 with the cam follower pointing toward the central axis of front one-piece enclosure 20. Next, referring to FIG. 9, bearing 22 is installed into front one-piece enclosure 20. Next, referring to FIG. 10A and FIG. 10B, while holding front one-piece enclosure 20 in one hand and flex rotor shaft 34 in the other hand, place the cam follower of reciprocating piece 50 into the cam groove of rotating piece 40. While keeping the cam follower and cam groove engaged, slide front one-piece enclosure 20 toward rotating piece 40 until the coaxial shaft of rotating piece 40 fully engages the center hole of bearing 22. Next, referring to FIG. 11A and FIG. 11B, slide rear one-piece enclosure 30 towards front one-piece enclosure 20, engage and finger tighten the large threads, and then install thumbscrew 32 into rear one-piece enclosure 30 and tighten against flex rotor shaft 34. The reciprocating adapter is now installed and is ready to accept a tool holder/collet and any desired cutting tool.

[0077] Disassemble in the reverse order described above except that bearing 22 can be left in place in front one-piece enclosure 20 indefinitely.

[0078] Front one-piece enclosure 20 functions as a slidable enclosure for reciprocating piece 50. Front one-piece enclosure 20 functions as an enclosure and a retainer for bearing 22. Front one-piece enclosure 20 functions as a partial enclosure for rotating piece 40. Front one-piece enclosure 20 includes female threads inside its major diameter to mate with the male threads of rear one-piece enclosure 30. Front one-piece enclosure 20 is shaped to accommodate holding my hand-held, reciprocating attachment in much the same way as one would hold a standard hobby knife, a pencil, or an air brush. A preferred embodiment of front one-piece enclosure 20 includes a knurled area around its minor circumference, the barrel-like portion, to promote a more secure and safer grip by an operator's fingers while allowing the assembly to rest over the top of the operator's hand in much the same way as one would hold an air brush. For tool attachments such as carving gouges and chisels the front one-piece enclosure can be grasped by cupping one's hand over the top and grasping the knurled area with one's thumb and forefinger in much the same way as one would hold a manual gouge.

[0079] Rear one-piece enclosure 30 functions as an enclosure for the end of flex rotor shaft 34. Rear one-piece enclosure 30 functions as a partial enclosure for rotating piece 40. One end of rear one-piece enclosure 30 is terminated in male threads for mating to the female threads of front one-piece enclosure 20. Rear one-piece enclosure 30 provides a non-slip surface for hand tightening to, or loosening from, front one-piece enclosure 20. Rear one-piece enclosure 30 provides a threaded hole whereby thumbscrew 32 can be tightened against flex rotor shaft 34 thereby securing my hand-held, reciprocating attachment to flex rotor shaft 34.

[0080] Bearing 22 provides low-friction rotative support for the coaxial shaft of rotating piece 40 and rests snuggly in position in a recess of front one-piece enclosure 20 in coaxial alignment with rotating piece 40.

[0081] Rotating piece 40, a one-piece item, provides a cam groove for the cam follower of reciprocating piece 50 whereby reciprocating motion is imparted to reciprocating piece 50 as rotating piece 40 rotates. Rotating piece 40 provides variable amounts of stroke for reciprocating piece 50, the exact amount of stroke being determined at the time of manufacture of a particular rotating piece 40. Rotating piece 40 functions as the mechanical connection to flex rotor shaft 34 in order to couple rotational drive to my hand-held, reciprocating attachment. Rotating piece 40 connects to flex rotor shaft 34 by way of coaxially aligned female-to-male mating threads. Rotating piece 40 connects to bearing 22 by way of a shaft coaxially aligned with center of bearing 22.

[0082] Reciprocating piece 50, a one-piece item, slidably mounts in front one-piece enclosure 20 and provides a cam follower on one end for the cam groove of rotating piece 40 whereby the cam action results in reciprocating action of reciprocating piece 50 of a stroke length determined by the cam groove offset. The other end of reciprocating piece 50 extends slightly past the small end of front one-piece enclosure 20, even at its rearmost point of travel, and provides an attachment point for a tool holder or collet so that various cutting tools may be utilized. A portion of reciprocating piece 50 on the same side as the cam follower of reciprocating piece 50 in aposition to rotating piece 40 is relieved just enough to provide clearance from the main body of rotating piece 40 and the relief is curved around a portion of the main body of rotating piece 40 so as to prevent rotation of reciprocating piece 50 which, in turn, prevents disengagement of the cam follower on reciprocating piece 50 from the cam groove on rotating piece 40.

[0083] There are numerous possibilities with regard to a method of manufacture, size, shape, material, and application. Methods of manufacture can include, but are not limited to, machining, molding, casting, molding with secondary machining, casting with secondary machining, and metal injection molding. Methods of attaching various pieces to each other can vary to accommodate various assembly techniques and methods of attachment to external drive mechanisms can be varied. For example, a rotating piece can be made with a coaxial shaft, reference numeral 40A, FIG. 16, of various diameters and lengths in lieu of female threads for installing into various commercially available chucks/collets, selected from the group consisting of chucks, collets, and adapters, found on various rotor tools. The female threads of the rotor can be specified in different sizes and depth for installing onto various rotor tools. Also, the method of attachment of the cutting tools to the reciprocating piece can be varied to allow for reciprocation of a cutting tool in the vertical plane, the horizontal plane, or anything in between. Also, the method of attachment of the cutting tools to the reciprocating piece can be varied by, including but not limited to, replacing the female threads of the preferred embodiment, illustrated in FIG. 6A, reference numeral 50, with larger female threads to accept larger collets, illustrated in FIG. 13C, reference numeral 50C, or with various sizes of male threads, illustrated in FIG. 13A, reference numeral 50A, or various sizes of an integral one-piece split collet with a separate tightening band, illustrated in FIG. 13B, reference numeral 50B. Sizes of various pieces, and internal dimensions thereof, can be varied to adapt to various external rotary drive mechanisms and to various sizes of cutting blades, carving blades and gouges, saw blades, chisels, files, and sanding devices for various applications. For example, a front one-piece enclosure and rear one-piece enclosure can be re-sized externally and internally for adapting to larger or smaller diameter external drive mechanisms. Referring to FIG. 14A and FIG. 15, an alternative of the rear one-piece enclosure, reference numeral 30A, can be adapted for direct attachment to a power rotary tool instead of to the flex rotor shaft of a power rotary tool. Referring to FIG. 14B and FIG. 15, another alternative of the rear one-piece enclosure, reference numeral 30B, can be adapted for direct attachment to a different style of power rotary tool, FIG. 14B and FIG. 15. Shapes can be altered to satisfy various mechanical or ergonomic/human engineering needs, such as, but not limited to, shape of form-fitting hand grip for right-handed and/or left-handed users. Additionally, a form-fitting hand grip, or any desired outside shape, can be in the form of a molded shroud around the tool. Additionally, an outside shroud can be of foam-like material. Materials for any of the pieces can include, but are not limited to, various metal alloys, various long-wear and/or self-lubricating alloys or engineering plastics or resins, ceramics, composites, or combinations thereof. Applications can include, but are not limited to, odd jobs, home repair jobs, arts and crafts, hobby projects, sculpture, electronic printed-circuit board rework, picture frame mat cutting, and professional model building.

[0084] Accordingly, the reader will see that the high-speed, hand-held reciprocating assembly for cutting, carving, sawing, chiseling, filing, sanding, and engraving of the subject invention provides a very versatile, very compact, easy-to-use, reliable, economical device that can be used to perform various types of fine detail work on numerous types of materials with numerous types of cutting tools. Furthermore, my hand-held, reciprocating attachment has the additional advantages in that

[0085] it serves as an attachment, in its various configurations, for existing flex rotor shaft extensions of power rotary tools and for direct attachment to existing power rotary tools without the flex rotor shaft extensions thereby making it more economical for hobbyists and professional consumers to expand the capabilities of their workshop while being able to avoid the extra cost of a built-in motor and its associated parts;

[0086] its design accommodates all types of small cutting tools requiring reciprocating action instead of being dedicated to just one or two types of cutting tools thereby making it much more versatile;

[0087] its design accommodates the use of a hardened point tool for engraving thereby eliminating the need to own a separate, motorized engraving tool;

[0088] it allows the consumer the option of using his or her existing compatible tool holders/collets and various cutting tools thereby making it even more economical and attractive for the consumer;

[0089] it comprises a minimum number of pieces thereby making it more economical and reliable;

[0090] its design eliminates the need for springs, gears, pins, clips, clamps, nuts, bolts, washers, and other such wear dependent pieces thereby also making it more reliable;

[0091] its simplicity allows for quick and easy assembly and attachment to the rotary power source without the need for any assembly tools;

[0092] its high-speed capability allows for material cutting and/or material removal in a minimum amount of time and with less force applied by the user thereby minimizing operator fatigue;

[0093] its reciprocating cutting tool, being on the assembly's extremity with no interfering pieces, allows deep, perpendicular cuts, and cuts at any angle, in cramped spaces that exceed the radius-depth limitations of rotary cutting tools;

[0094] its variable-speed, short-stroke reciprocating action allows for use on delicate work pieces by eliminating the potential loss of control of a spinning cutting tool, which is prevalent in rotating cutters, grinders, and sanders, thereby making the operation safer for both the user and the work piece;

[0095] its reciprocating stroke length is variable by easily changing rotating pieces; and

[0096] its short-stroke reciprocating action allows a rotary tool to be adapted for the novel use of miniature chisels on fine, delicate work pieces such as, for only one example, inlay operations.

[0097] While my above description contains many specificities, these should not be construed as limitations on the scope of my hand-held reciprocating attachment, but rather as an exemplification of one preferred embodiment thereof. Many other variations are possible. For example, the front and rear one-piece enclosure can be made smaller or larger with different sized openings to accommodate various rotary drive tools and/or their flex rotary shaft extensions and the individual pieces of my hand-held reciprocating attachment can be made in different sizes; the housings can be of different shapes or contours to match different rotary tool requirements and/or for reasons of aesthetics and ergonomics; the pieces can be made in different colors and/or types of surface finishes; the rotating piece with integral cam can be made smaller or larger and the cam groove can be varied to create various stroke lengths for the reciprocating cam follower; the rotating piece can be made with a shaft of various sizes, in place of the female threads, for mounting in chucks and collets; the individual pieces of my hand-held reciprocating attachment can be made of various materials; the reciprocating piece can have its exposed end altered to accept various sizes and styles of tool holders/collets and the tool holders/collets can be various shapes and sizes to accept various tool attachments; the various pieces of my hand-held reciprocating attachment can be made using various manufacturing methods, including but not limited to, machining, casting, molding, casting with secondary machining, molding with secondary machining, and metal injection molding; the thumbscrew, used for securing my hand-held reciprocating attachment to the externally supplied power rotary source, can be replaced with a plurality of thumbscrews, or set screws, or a twist-lock mechanism, or various other methods of securing my hand-held reciprocating attachment to the power rotary source, etc.

[0098] Thus the scope of my hand-held, reciprocating attachment should be determined by the appended claims and their legal equivalents, rather than by examples given.