GB126804A - Improved Earth Boring Machine. - Google Patents

Abstract

126,804. Murphy, E., and Anzulovich, A. V. May 17, 1918. Bore-hole apparatus.-An earth - boring machine actuated by electric motors enclosed therein comprises three independent connected sections, the upper one J, Fig. 1, enclosing the suspension and anchoring means, the intermediate one K, Figs. 1 and 3, containing the motors and speedreducing gear, and the lower one L, Figs. 3 and 6, containing the boring-bit. The sections are connected by bolts &c. 22, 44. The anchoring-means comprises blades 16 connected by links 15 to a fixed spider 14 and by further links 17 to a collar 18 on a spring-pressed rod 10 connected to the suspension means 7; on the machine reaching the bottom of the bore-hole, expansion of the spring 13 forces the blades 16 through slots in the casing 1 to engage the surrounding earth. The electric conductors are connected to a closure 3 which is rotatable on the casing 1 and carries spring contacts 5 engaging contact rings 6. The electric motors are arranged in independent chambers M and their co-axial shafts 26, 26<1>, 26<11> are connected to drive a shaft 30 carrying pinions 29, 36 of different diameters; these pinions engage pinions 31, 35 mounted on common shafts 33 carried by a rotatable spider 32 and the pinions 31 engage a fixed internallytoothed wheel 28 and so cause the pinions 35 to rotate an internally-toothed wheel 37, and a shaft 41 carried thereby, at reduced speed. The shaft 41 has a square end 52 which rotates a tube 51 which is slidable thereon and carries the bit 58. A non-rotating nut 49 connected to the tube 51 engages a threaded part 48 of the shaft 41 to advance or withdraw the bit. The bit is of helical form and enclosed in a cylinder 59 rotating with the bit; the cylinder 59 and outer case 47 have doors for removal of the debris. At the end of either the advance or withdrawal of the bit, the motors are automatically stopped by the nut 49 contacting with stops and so exerting a pull on a cord enclosed in a tube 69, Fig. 9; the cord pulls down a rod 70 against the action of a spring 72, which rod, through engaging projections 73, 74, moves a rod 76 against the resistance of a spring 80 and so causes a crank 78 to open the switch; on depressing a button 85, a bell-crank lever 81 overcomes a spring 74' and disengages the projections 73, 74, the spring 80 then returning the rod 76 and re-closing the switch.