Convex curve cutter
OwnerMartin L. Shoffnerinventor
Life of this patent
Estimating the term…
Abstract
A portable bandsaw attachment for cutting symmetrical or asymmetrical convex curved sides into a multisided three dimensional workpiece comprising a rotating table that supports the workpiece, a stationary base that supports the rotating table and provides an attachment point for the rotating table, laterally movable guides and backstop arrangement attached to the rotating table for locating and securing the workpiece relative to the bandsaw blade. The attachment can include handles to grip and turn the rotating table, an opening in the stationary base to provide clearance for the bandsaw blade, and means for securely mounting the stationary base to the bandsaw table.
Claims16
A portable bandsaw attachment permitting the cutting of symmetrical and asymmetrical convex curved surfaces into a multisided three dimensional workpiece, comprising:
- a rotating table configured to support the workpiece on a bandsaw table;
- a stationary base configured to support the rotating table on the bandsaw table and to provide an attachment point for the rotating table, where the rotating table is configured to rotate with respect to the stationary base about the attachment point;
- and
- two or more laterally movable guides attached to the rotating table and configured to locate a first side of the workpiece relative to a bandsaw blade on a predetermined center of curvature of a convex curve to be cut into the first side of the workpiece, wherein rotation of the rotating table relative to the stationary base rotates the moveable guides and the workpiece relative to the bandsaw blade such that when the bandsaw blade is operating and aligned to cut the first surface, the first surface rotates relative to the bandsaw blade as the bandsaw blade is cutting the first surface to create a convex curvature into the first surface.
A method for cutting smooth and consistent symmetrical and asymmetrical convex curves into a workpiece comprising:
- providing a rotating table that supports the workpiece in a stable position by means of movable guides which are attached to the rotating table by multiple knobs;
- providing a stationary base structure that supports the rotating table and provides an attachment and pivot point for the rotating table;
- providing a protuberance on the underside of the stationary base that is configured to mate with a mitre gauge channel on the bandsaw table;
- providing an opening in the stationary base to provide clearance for a bandsaw blade;
- providing a removable pin which can be used to adjust the pivot point for the rotating table;
- providing a movable backstop which moves perpendicularly to the two movable guides;
- marking two boundary lines on a face of the workpiece within which a convex curve will be cut, marking an apex point representing an apex of curvature of the convex curve proximate to the two boundary lines and proximate to the edge of the wood block, using a curve template with multiple curves of different radii, placing the template on the workpiece, and determining which size radius curve to cut from the multiple different radius curves on the template;
- removably attaching the stationary base to a bandsaw table with magnets and clamps, attaching the rotating table to the stationary base and setting the radius curve determined from the template by inserting the removable pin through the rotating table at a reference point representing the predetermined radius and into a hole in the stationary base;
- placing a workpiece on the rotating table between the two movable guides with the lateral position of the box determined by the apex point, adjusting the movable guides so that they rest securely against both sides of the workpiece, securing the movable guides to the rotating table by tightening the knobs, rotating the workpiece so that it is clear of the bandsaw blade, moving the workpiece in a longitudinal direction until the blade teeth are positioned against the cut line, moving the backstop until it rests against the wood block, and securing the backstop to the rotating table;
- making a curved cut in the workpiece by rotating the rotating table and workpiece towards the teeth of the bandsaw blade until the blade has cleared the workpiece, rotating the box towards the rear of the rotating table, re-securing the movable guides, lining up the saw blade at a desired cut line, re-securing the backstop, and repeating this last step until curved cuts have been made in all sides of the workpiece.
Dependencies are inferred from the claim text.