Gear tooth profile

Claim 2

A tooth profile for gearing in which the tooth tip follows no more than 180* of the true arc of a circle, with the center point of said tip arc on a radial line bisecting the tooth, the dedendum arcs both follow identical circular arcs, with the radii of the dedendum arcs being greater than the radius of the tip arc, and the adjacent ends of the dedendum arcs and the tip arc blending with and being joined by a straight line to form the flanks of the tooth, the radial extensions of said straight lines forming acute angles with an extension of said radial line at a point radially beyond said tip.

Claim 3

A tooth profile according to claim 1 in which the tooth profile has the following relationship to an isosceles triangle in which the apex angle equals 360* /n where n is a whole number greater than two: a. the tooth tip radius center point is on a line bisecting the apex angle of said triangle, said radius being no greater than one-fourth of the length of the base of said triangle b. the dedendum arcs have their center points at the base angles of said triangle.

Claim 4

A tooth profile according to claim 2 in which said tooth tip radius is at least 0.0015 inch less than one-fourth the length of the base of said triangle.

Claim 5

A tooth profile according to claim 3 in which n is at least eight and the center point of said tooth tip radius is on the base line of said triangle.

Claim 6

A tooth profile according to claim 3 in which n is at least eight and the center point of said tooth tip radius is outside the said triangle.

Claim 7

A method of designing a gear tooth according to claim 1 comprising the steps of (1) laying out an isosceles triangle having an apex angle equal to 360* /n where n is a whole number greater than two, (2) establishing a centerline bisecting the apex angle, (3) drawing a circular tip arc of not more than 180* which tip arc has its center on or outside the base of said triangle and on said centerline, the said tip radius being less than one-fourth the length of said base, (4) drawing circular dedendum arcs within said triangle, said dedendum arcs having radii no greater than one-fourth the length of said base and having their respective center points at the base corners of said triangle, and (5) drawing straight lines connecting the tip arc with the adjacent dedendum arc to form the flanks of said tooth, the radii of the tip arc and dedendum arcs being so selected that said flank lines intersect said centerline at a point outside said triangle and form an acute angle therewith.