GB560200A - Improvements in or relating to clinometers - Google Patents

Abstract

560,200. Borehole &c. clinometers. TEMPLETON, J. C. (Winkler, L. T., partly). Sept. 10, 1942, No. 12806. [Classes 97 (ii) and 97 (iii)] [Also in Group XIX] A clinometer suitable for use in boreholes and the like comprises a frame which aligns itself with the borehole when lowered therein, a chart, gyroscopic means for maintaining the chart in, or indicating on it, a predetermined azimuthal setting, pendulous means capable of indicating the inclination of the frame in any direction from the vertical, means for lowering the device in the borehole, and means operable by a change in its lowering movement for recording the inclination on the chart. As shown, a cylindrical container 10 which aligns itself with the bore hole as it is lowered thereinto contains a free gyroscope 14 for stabilizing in azimuth a frame 12 mounted on vertical pivots 13. The gyroscope may be driven by batteries located in the bottom of the container. The frame 12 also carries a spring- supported mass 18, a universally-mounted pendulum 23, a pendulum-clamping device 24, a delay action device 22, a recording strip 25 and an electric motor 28 fed through slip rings 29. In operation, the gyroscope maintains the initial orientation of the frame 12 as the device is lowered down the borehole. When the descent is suddenly arrested, the mass 18 moves downward by its own inertia and momentarily closes an electric contact 21 to start a cycle of operations including clamping of the pendulum 23 after delay by the device 22, recording the position of the pendulum on the strip 25 (for example, by projecting a needle from the pendulum to perforate the strip), releasing the pendulum, and feeding the strip in readiness for. repetition of the operation. The strip may be marked with polar co-ordinates, or means may be provided for marking on the strip the central position of the pendulum. In a modification, the strip is mounted on the container instead of on the frame 12, the direction in azimuth being indicated by marking a point on the strip according to the azimuthal setting of the frame. Instead of using the inertia of the mass 18, the sequence of operations may be initiated by the movement of a switch-controlling flap actuated by the passage of borehole fluid through a channel in the container 10 as the container is lowered. When a record is required of the inclination at the bottom of the borehole only at the end of a day's working, the recording strip 25 is dispensed with and a graduated saucer-shaped dial is provided below the pendulum, the mechanism being arranged to maintain the clamping device 24 in locked condition so that the clinometer may be withdrawn to the surface for reading. The switch for initiating the recording operation may be actuated by a contact pin 37, Fig. 2, extending through the bottom of the container 10 from a fluid-filled, compartment 36. To prevent the pin from being pushed in by the pressure of the borehole liquid before the pin strikes the bottom of the borehole, a plunger 38 of larger diameter than the pin projects into the fluid-filled chamber.