Spiral Bubble Rotation Indicator
A rotation indicator assembly having an inner sleeve with an outer surface surrounded by an outer sleeve. The outer sleeve seals a spiral pathway between the inner and outer sleeves. The spiral pathway is filled with at least a first material and a second material of different densities, for example a liquid and a gas.
1 . A rotation indicator, comprising:
an inner sleeve having an outer surface surrounded by an outer sleeve;
the outer sleeve covering an open end of a spiral channel around the outer surface, forming a spiral pathway;
the spiral pathway filled with a first material and a second material;
the first material and the second material having different densities.
2 . The rotation indicator of claim 1 , wherein the inner sleeve has a mounting bore along a longitudinal axis.
3 . The rotation indicator of claim 1 , wherein the outer sleeve has graduated indicia.
4 . The rotation indicator of claim 3 , wherein the graduated indicia has circumferential and longitudinal increments.
5 . The rotation indicator of claim 3 , wherein the graduated indicia is integral with the outer sleeve.
6 . The rotation indicator of claim 1 , wherein the outer sleeve is translucent.
7 . The rotation indicator of claim 1 , wherein the spiral pathway has more than one turn around the inner sleeve.
8 . The rotation indicator of claim 1 , wherein the first material is a liquid and the second material is a gas.
9 . The rotation indicator of claim 8 , wherein the first material is luminous.
10 . The rotation indicator of claim 1 , wherein the first material and the second material are immiscible.
11 . The rotation indicator of claim 1 , further including a third material in the spiral pathway.
12 . The rotation indicator of claim 11 , wherein the third material has a higher density than the first material and the second material.
13 . The rotation indicator of claim 11 , wherein the third material is one of mercury and a metal ball.
14 . The rotation indicator of claim 1 , wherein the spiral channel is formed extending to an end of the inner sleeve with an open side at the end; and the outer sleeve is formed to seal also against the end.
15 . A rotation indicator, comprising:
an inner sleeve having a mounting bore along a longitudinal axis and an outer surface surrounded by a translucent outer sleeve;
the outer sleeve covering an open end of a spiral channel around the outer surface, forming a spiral pathway having more than one turn around the inner sleeve;
the outer sleeve having integral graduated indicia with circumferential and longitudinal increments;
the spiral pathway filled with a luminous liquid and a gas.
16 . A rotation indicator, comprising:
an inner sleeve;
an outer sleeve;
the inner sleeve dimensioned to fit within the outer sleeve, sealing a spiral pathway between the inner sleeve and the outer sleeve;
the spiral pathway filled with at least a first material and a second material;
the first material and the second material having different densities.
17 . The rotation indicator of claim 16 , further including graduated indicia visible from an exterior of the rotation indicator.
18 . The rotation indicator of claim 17 , wherein the graduated indicia include both longitudinal and circumferential graduations.
19 . The rotation indicator of claim 16 , wherein the first material is a liquid and the second material is a gas.
20 . The rotation indicator of claim 16 , wherein the spiral pathway has more than one turn.