GB733127A - Improvements in earth strata cutting indicators for remotely controlled bore mining machines - Google Patents

Abstract

733,127. Electric indicating systems. UNION CARBIDE & CARBON CORPORATION. Sept. 10, 1953 [Sept. 19, 1952], No. 25041/53. Addition to 689,415. Class 40 (1). The system of the parent Specification is modified by using in lieu of the carbon-pile detector, a pick-off transformer energized from an oscillator, and having a core mechanically connected to the scanning auxiliary cutting tooth mounted on the rotary cutting head of the bore mining machine, the transformer secondary being coupled to the oscilloscope. The scanning tooth is also mounted so as to respond to cutting torque rather than vibration as is the case in the parent Specification. The scanning tooth is mounted in front of the main cutting tooth and a two-phase generator driven synchronously with the cutting head is used for the C.R.T. time base. Several scanning teeth and associated C.R.T. indicators may be used respectively with a number of cutting heads. Detector construction, Fig. 6. The scanning tooth 14 is fixed to a lever 10 pivoted at 30 to a support 11 carried by the cutting head (not shown). The arm 20 of the lever 10 is held between a resilient stop 18 and a compression spring 22 adjustable at 32 so that the lever is rocked against the spring action in accordance with the hardness of the strata engaged by the tooth and moves the armature 28 within the transformer 24 correspondingly. Both transformer and core are adjustably mounted for zeroizing purposes. Detector construction, Fig. 7. The tooth 45 is detachably but rigidly secured to a lever 43 pivoted at 53 to the frame 41 secured to the cutter head 61. The armature 59 of the pickoff transformer 55 is adjustably carried by an extension 51 of the lever 43 which is deflected in opposition to an annular rubber shear mount 49. Detector construction, Figs. 1, 3, 4. The scanning tooth 130 is carried by a short arm 127 at the end of a shaft 125 carrying a lever 123 at its opposite end which is deflected in opposition to a spring 109 and actuates the pick-off transformer armature 163 through a rod 165, Fig. 3. Both the spring 109 and a counter-spring 135 are adjustably mounted and so are the rod 165 and the pick-off transformer. The whole is enclosed in a casing secured to the cutter head 161. Detectors may be mounted on both the left and right cutter heads of a bore mining machine. Circuitry, Fig. 5. The right and left cutter head detectors R, L have their transformers energized from an oscillator 190 over a screened cable 196 and slip rings 188. The detector outputs are fed by way of slip rings 188 and cable matching transformers 208, 210 to respective oscilloscope circuits 230, 220, the circular time bases of which are derived from a twophase generator 228 driven synchronously with the cutter heads. The R, L oscilloscopes are calibrated to indicate torque applied to the scanning teeth.