Abstract: An adjustable earth boring device for provides a strong, easy to use, adjustable mount for cutters on earth boring devices. In a preferred embodiment, the device includes a grooved, wedge-shaped pocket and matching cutter segment with means to secure the cutter segment in the pocket. The wedge shaped pocket in the boring head is axially aligned with the boring device. Each side of the pocket has deep grooves somewhat resembling bolt threads. A slot in the rear of the pocket receives a bolt to secure the segment tightly in place. Threaded holes in the bottom of the pocket receive bolts through the cutter segment for a back up securing means. The cutter segment has a rolling cone cutter or series of blades or picks for cutting earth formations on the head end and a wedge shaped mounting body supporting it. The grooves are constructed such that the segments can be mounted at differing heights from the centerline of the boring head, thus determining the diameter which the boring device will cut.

Abstract: This invention is directed toward a fiber optic modulation and demodulation system, and more particularly directed toward a telemetry system for relaying signals from sensors in remote, harsh environments. Light is modulated using one or more optical reflective grating and piezoelectric crystal combinations, and demodulated using an interferometer system. The one or more modulators are driven by the responses of one or more sensors thereby modulating one or more carrier wavelengths of a carrier light source. The modulated light signal is transmitted from the sensor or sensors, over an optical fiber, to an interferometer which is used to demodulate the reflected signals and thereby determine the responses of one or more sensors. One embodiment of the invention set forth is that of a telemetry system linking sensors within a borehole to detection and processing equipment at the surface of the earth.