# US 4,397,593 A · Tool for cutting openings > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,397,593 A - Document ID: US4397593A - Status: Granted - Kind: A - Application number: 06/230,377 - Filed: 1981-02-02 - Granted: 1983-08-09 - Earliest claimed: 1981-02-02 - Inventors: William A. Fordeck - Web page: https://patentgrep.com/patent/US4397593A ## CPC - B23C 1/20: Portable devices or machines (details or components, e.g. casings, bodies, of portable power-driven tools not particularly related to the operation performed B25F5/00); Hand-driven devices or machines - Y10T 408/352: including rotating cutter other than rotating, axially moving Tool - Y10T 409/30448: with detachable or auxiliary cutter support to convert cutting action - Y10T 409/306384: with work supported guide means - Y10T 409/30644: to guide tool to move in arcuate path - Y10T 409/30756: Machining arcuate surface - B23C: MILLING (broaching B23D; broach-milling in making gears B23F; arrangement for copying or controlling B23Q) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The invention is a tool for use with a machine tool such as a drill press or the like for cutting circular openings or segments thereof in sheet material. The device includes a pilot drill and an articulated gear train operatively coupling a tool holder and cutting tool to a pilot drill. The articulated gear train is received within a housing which is rotatable about the axis of the pilot drill to enable movement of the cutting tool along an arcuate path about the axis of the pilot drill. ## Claims ### Claim 1 A tool for cutting openings in a workpiece comprising: a housing; an articulated arm received in said housing, said arm having a proximal and distal end and a plurality of sections pivotable about spaced parallel axes, such that the distal one of said axes is movable between positions close to and distal from the proximal one of said axes; a plurality of gears journalled in said sections, each said gear being journalled for rotation about a predetermined one of said axes; and said gears being operatively meshed in series to form an articulated gear train; a pilot drill fixedly connected to the proximal one of said gears for rotation about the respective axis, said drill having a shank portion extending outwardly from said housing and being operatively engageable by a machine tool, said housing being manually rotatable about said drill; tool holding means fixedly connected to the distal one of said gears for rotation therewith about the distal one of said axes, whereby said pilot drill is drivingly coupled to said tool holding means; and clamping means for fixedly securing said distal section to said housing with said distal axis disposed at a selected spacing from said proximal axis. ### Claim 2 (depends on 1) The device of claim 1 wherein said clamping means includes an elongated slot formed in said housing, a threaded stud fixedly secured in said distal one of said sections and extending outwardly of said housing through said elongated slot, a threaded element received on said threaded stud, and a cutting tool secured to said tool holding means for rotation about said distal axis. ### Claim 3 (depends on 2) The device of claim 2 wherein said gears are spur gears, that one of said spur gears that is coupled to said pilot drill having a diameter greater than the others of said gears whereby the rotational speed of said tool holding means is greater than the rotational speed of said pilot drill. ### Claim 4 (depends on 3) The device of claim 3 wherein said housing is closed and includes an inner cavity dimensioned to accomodate movement of said sections therein. ### Claim 5 (depends on 4) The device of claim 4 wherein each said section comprises an upper and a lower plate fixedly secured together in parallel spaced-apart relationship, there being axles fixedly secured to said plates to extend therebetween, a gear rotatably mounted on each axle, each said section being pivotable about a respective one said axle. ### Claim 6 (depends on 2) The device of claim 2 wherein each said gear is a compound gear having an upper and a lower gear section of respectively different diameters, the smaller of each said gear engaging the larger of each said gear operatively preceding it in said gear train. ### Claim 7 (depends on 6) The device of claim 6 wherein said pilot drill includes a cutting portion and a smooth portion. ### Claim 8 (depends on 5) The device of claim 5 further including a guide means fixedly secured to said housing adjacent said pilot drill for slidably engaging a workpiece and stabilizing said device thereagainst while said housing is rotated about said drill. ### Claim 9 (depends on 1) The device of claim 1 wherein each section comprises two spaced apart plates, the plates of one section being interleaved with the plates of an adjacent section, axles coincident with said axes, respectively, interconnecting the plates of adjacent sections, said gears being mounted on said axles, respectively, said tool-holding means including a hub on said distal gear, and a milling cutter tool removably secured to said hub. ### Claim 10 (depends on 9) The device of claim 9 wherein said clamping means includes a threaded stud operatively secured to the distal one of said sections, and a knob element adjustably mounted on said stud to engage and lock selectively against said housing. ### Claim 11 (depends on 8) The device of claim 8 wherein said guide means includes an elongated flat element secured in spaced relation to said housing, said flat element lying in a plane normal to said axes and extending from the proximal axis to the distal axis, said flat element having a straight slot extending between said proximal and distal axes and receiving therethrough said pilot drill and cutting tool.