Multi-turn limit stop apparatus

Claim 2

A multi-turn stop mechanism comprising: a. first rotary means having a first axis of rotation; b. second rotary means having a second axis of rotation parallel to the first axis of rotation; c. means for coupling the first rotary means to the second rotary means so that there is a turns ratio between them, with the turns ratio of the second rotary means to the first rotary means a mixed number substantially greater than one; d. a first stop member affixed to the first rotary means, said first stop member having a first contact surface lying entirely within a cylinder defined by all points which are at a radius from the first axis of rotation equal to the quotient obtained in division of the distance between the first and second axes of rotation by the sum of the inverse of the turns ratio and the integer one; e. a second stop member affixed to the second rotary means, said second stop member having a second contact surface which may interfere in rotation with the first stop member contact surface, said stop member contact surface having an outermost segment, with the distance from the second contact surface outermost segment to the second axis of rotation less than the distance from the first axis of rotation to those points on the first stop member contact surface furthest away from said first axis, whereby the two contact surfaces engage, limiting rotation in one sense, after a number of first rotary means rotations greater than one.

Claim 3

The apparatus of claim 1 wherein the first rotary means is a circular gear having a pitch circle, the second rotary means is a circular pinion, so that the radius of the cylinder within which the first contact surface lies is equal to the pitch radius of the circular gear pitch circle.

Claim 4

In combination with a power train of the type wherein a circular gear mounted for rotation about a first axis and having a first pitch radius is in meshing engagement with a circular pinion mounted for rotation about a second axis, said pinion having a second pitch radius, with the ratio of the first pitch radius to the second pitch radius a mixed number greater than two, the improvement which comprises: a. a first stop member which rotates with the circular gear, said first stop member having a first contact surface positioned such that the distance from the first stop member cOntact surface to the first axis of rotation is less than the first pitch radius; b. a second stop member which rotates with the circular pinion, said second stop member having a second contact surface positioned so that the first contact surface and the second contact surface interfere in rotation, the distance from the second stop member contact surface to the second axis of rotation being less than the distance from the first stop member contact surface to the first axis of rotation, the second stop member contact surface having an outermost segment which, with respect to a frame of reference fixed on the circular gear pitch circle, moves with the circular pinion in revolution about the circular gear during gear rotation, said outermost segment sweeping out a plurality of epitrochoidal loops with respect to the reference frame during gear rotation, whereby the rotation of the power train in either sense is limited to a number of circular gear rotations greater than one.

Claim 5

In combination with a power train of the type wherein a circular gear mounted for rotation about a first axis and having a first pitch radius is in meshing engagement with a circular pinion mounted for rotation about a second axis, said pinion having a second pitch radius, with the ratio of the first pitch radius to the second pitch radius a mixed number greater than two, the improvement which comprises: a. a first stop member which rotates with the circular gear, said first stop member having a first contact surface positioned such that the distance from the first stop member cOntact surface to the first axis of rotation is less than the first pitch radius; b. a second stop member which rotates with the circular pinion, said second stop member having a second contact surface positioned so that the first contact surface and the second contact surface interfere in rotation, the distance from the second stop member contact surface to the second axis of rotation being less than the distance from the first stop member contact surface to the first axis of rotation, the second stop member contact surface having an outermost segment which, with respect to a frame of reference fixed on the circular gear pitch circle, moves with the circular pinion in revolution about the circular gear during gear rotation, said outermost segment sweeping out a plurality of epitrochoidal loops with respect to the reference frame during gear rotation, whereby the rotation of the power train in either sense is limited to a number of circular gear rotations greater than one.

Claim 6

The apparatus of claim 3 wherein the first stop member contact surface is a segment of a cylinder whose axis is coincident with the circular gear axis, and the second stop member contact surface is a segment of a cylinder whose axis lies outside the pinion pitch circle.

Claim 7

The apparatus of claim 3 wherein the first stop member contact surface is positioned to lie within only one of the epitrochoidal loops generated by the second stop member contact surface during a number of gear rotations equal to the denominator of the fractional part of the turns ratio, when that fraction is reduced to lowest terms.

Claim 8

The apparatus of claim 5 wherein the epitrochoid axis of the epitrochoidal loop within which the first stop member contact surface lies is perpendicular to said first axis, and the first stop member contact surface is configured to be symmetrical about the epitrochoid axis.