ARCHONOS: PIVOTING PROTRACTOR–RULER MEASUREMENT TOOL

Referring generally to FIGS. 1–5, an embodiment of the measurement tool comprises a base body and a rotatable arm connected about a pivot axis. The base body includes one or more indexing surfaces that can register against an edge or a corner of a workpiece. The arm carries a linear scale for distance measurement. Relative rotation between the base body and the arm is readable on an angular scale such that the tool can measure and set angles while also serving as a ruler and marking guide. In one embodiment, the base body comprises: • a reference edge (or pair of orthogonal edges) configured to align with a workpiece edge; • a corner indexing feature such as a notch, hook, lip, or V-groove configured to engage a corner/vertex; • an angular scale printed, engraved, embossed, molded, or otherwise formed on the base body; and • a pivot aperture defining the pivot axis or receiving a pivot fastener. In some embodiments, the base body is generally planar. In other embodiments, the base body includes a thickness or structural ribs to increase stiffness. The base body may be manufactured by 3D printing (e.g., PLA, PETG, nylon, composites), injection molding, machining, stamping, or combinations thereof. In one embodiment, the rotatable arm comprises: • an elongated member defining a straightedge for drawing and alignment; • a linear scale along at least a portion of its length (metric, imperial, or both); • a pointer/index mark (or window) configured to indicate angle on the base body’s angular scale; and • a pivot coupling region to connect to the base body at the pivot axis. The arm may be symmetric or may include a widened region near the pivot for rigidity and improved reading of the angular scale. The arm may include one or more marking apertures (e.g., holes, slots) at predetermined distances. The base body and arm are coupled at a pivot assembly that allows rotation about a pivot axis. Non-limiting pivot embodiments include: • a screw and nut (or bolt) passing through aligned apertures; • a rivet or pin; • a press-fit pin with friction washers; • a bushing or bearing insert; and/or • an integral snap-fit pivot for molded/printed parts. In some embodiments, the pivot assembly includes friction elements (e.g., washers, textured surfaces, elastomer rings) enabling the arm to hold its position while still being adjustable. The tool may include a mechanism to hold the arm at selected angles, such as: • a thumb screw or cam lock increasing friction at the pivot; • spring-loaded detents for common angles (e.g., 0, 15, 30, 45, 60, 90 degrees); • a ratcheting interface; • magnets interacting with ferromagnetic inserts at discrete positions; or • a clamp feature integrated into the base body. Detent mechanisms may improve repeatability for frequent layout tasks. The angular scale may be disposed on the base body, the arm, or both. The scale can be: • single-sided (0–180 degrees) or double-sided (left/right reading); • fine-graduated (e.g., 1-degree increments) or coarse-graduated with emphasized common angles; • printed, etched, embossed, engraved, laser-marked, or molded. In some embodiments, a pointer on the arm reads against a protractor arc on the base. In other embodiments, a window in the arm overlays the scale for parallax reduction. For fast alignment, the base body can include indexing geometry such as: • a right-angle notch to seat on a corner of a sheet or board; • a hook/lip to catch an edge (similar to tape measure hooks, but rigid); • a V-groove to align with convex corners or vertices; • a stepped ledge to align with thicknesses (e.g., paper vs. wood); • a removable or adjustable indexing insert. These features allow the pivot point to be placed at a repeatable reference location on the workpiece, supporting consistent angular layout. In use, the user may: 1. place the base body so an indexing feature engages a workpiece edge/corner; 2. rotate the arm to a desired angle while reading the angular scale; 3. lock or hold the angle using friction or a locking/detent mechanism; 4. measure a distance along the arm using the linear scale; and 5. draw or mark a line along the arm edge or through marking apertures. This provides combined functionality of a protractor, ruler, and adjustable straightedge.

Non-limiting examples include: • 3D printed polymers (PLA, PETG, ABS, nylon), optionally with metal inserts; • injection molded plastics with printed/laser-marked scales; • machined aluminum or stainless with etched scales; • composite laminates. Scales may be integrated at print time (raised/engraved geometry) or applied post-process (ink, laser, stickers, decals). The disclosure includes variations such as: • dual arms (two pivoting rulers); • integrated bubble level or plumb indicator; • removable arms of different lengths; • calibrated stop blocks for repeated distance marking; • digital angle sensing (optional) while retaining mechanical measurement; and/or • metric/imperial dual-scale configurations.