Trigonometric universal centering jig assembly
View Patent ↗For use upon machinery in a wood shop or any industrial facility where it is desired to operate upon an object's unmarked centerline, such as with a powered saw table, drill press or any other apparatus required for the task: The sine and cosine of a triangle—are used to assure that as a certain component is moved a given distance, a guide fence is moved transversely just a fraction of that distance—preferably one-half—away from or toward the task performing instrument—a saw blade, drill bit or other operable tool. Thus, if the distance moved by the component equals the width of the piece to be worked upon, where the trigonometric sine is such that the guide fence is moved half that distance, given certain further adjustment, the task performing instrument is caused to operate precisely upon the piece's centerline, represented by one-half its width.
1. A trigonometric universal centering jig for use on a power cutting tool having a work table, the trigonometric universal centering jig comprising:
a first component including:
a first plate having an upper surface and an underside, the first plate having a first edge and a second edge at an angle to the first edge;
a guide fence extending along the first edge of the first plate;
a movable curb extending from the plate, the movable curb extending from the second edge of the first plate;
a second component including:
a second plate having an upper surface and an underside, the second plate having an angled first edge disposed in abutted contact with the angled second edge of the first plate;
a sliding connector connected between the first plate and the second plate to maintain the angled first edge of the second plate in abutted contact with the angled second edge of the first plate, the sliding connector permitting sliding movement of the first plate relative to the second plate along the abutted angled edges of the first and second plates;
a clamp mounted to selectively secure the first and second plates in position relative to one another, the clamp being operable between a clamped state that prevents sliding movement of the first and second plates along the abutted angled edges and an unclamped state that permits sliding movement of the first and second plates along the abutted angled edges;
first and second translation fingers mounted at the second plate, the first and second translation fingers being selectively positionable on the second plate and being selectively fastable in position;
a translation rail extending from the underside of at least one of the first and second components; and
wherein the movable curb of the first component extends onto the second plate for selective contact with at least one of the first and second translation fingers.
2. A trigonometric universal centering jig as claimed in claim 1 , further comprising:
a handle on at least one of the first and second components.
3. A trigonometric universal centering jig as claimed in claim 1 , further comprising:
a first handle extending from the first component, the first handle being formed unitarily with the movable curb; and
a second handle extending from the second component.
4. A trigonometric universal centering jig as claimed in claim 1 , further comprising:
first and second toggle clamps mounted on respective ones of the first and second translation fingers, the first and second toggle clamps being operable between a position permitting sliding movement of the respective first and second translation fingers between a plurality of positions on the second plate and a position securing the respective translation finger in one of the plurality of positions on the second plate.