Patent ID: 6490802
Filing Date: 2002-12-10
Classification: G01C

Abstract:
An apparatus for determining the orientation with respect to gravity, wherein said apparatus comprising:a lower chamber that is filled with a liquid, and an upper chamber that is superimposed on the lower chamber, wherein said lower chamber and said upper chamber share a light communicating wall, wherein said light communicating wall is a window; a light transmitting cable that is transmitting light through the cable, wherein said cable has a source end which is an entrance point for the light, and an exit end that has an emitting light, and wherein said exit end is fitted with a flotation collar; a light source; a photodetector producing an electronic signal wherein said photodetector has a supporting electronic circuit, wherein said electronic signal correlates to an intensity and a spatial coordinate; wherein, the source end of the cable passes through a bottom wall of the lower chamber and is sealed to the bottom wall such that the cable is substantially vertically tethered to the bottom wall at a position that is substantially central and opposite to the window, and wherein the cable is tensioned by the floatation collar submerged in and buoyed by the liquid such that the cable is substantially straight, and long enough such that the exit end of the cable is in close proximity to the window; wherein the light source delivers light to the source end of the cable, the cable transmits the light to the exit end, and the emitting light projects a point light at the window; wherein, the upper chamber has a ceiling wall opposite the window, wherein on the ceiling wall is mounted the photodetector, wherein said photodetector is in a plane parallel to the window, wherein said electronic signal of the photodetector is specific to a position for the point light at the window; whereas, when the apparatus experiences an effective tilt, said tilt having both a direction and a magnitude, there is an equal and opposite response by the cable at the exit end, which causes the position of the point Light to move to a new position, and the photodetector detects the new position and therein generates a new electronic signal, wherein the intensity and spatial coordinates of the point light correspond to the magnitude and direction of tilt.