GB191324575A - Deep Drilling Apparatus. - Google Patents

Abstract

24,575. Petit, V. Oct. 29. Bore-hole apparatus.-In a percussive deepboring apparatus, the drill beam comprises two elements, one element A being connected to the driving-means, and. the other element being composed of two arms B and carrying the drill bar ; the first element is partly inserted between the arms composing the second element, while the free end of each of the two elements bears against the operative end of the other element by means of springs 11, 12 or the like. As the driving-crank descends, the springs 11, 12 are compressed and cause an upward movement of the drill bar ; at the latter part of the downward movement of the crank, the springs extend and throw the arms B upwards until they are stopped by contact of plates 1, 8 with the beam element A. The drill 44 continues its upward movement, owing to the provision of a sliding joint 43, and so has an increased stroke ; during this excess movement, the bore-hole is flushed, the sliding joint 43 forming a pump. The springs 11, 12 may be maintained compressed during the whole of the downward movement of the driving-crank, by the engagement with the plate 8 of projections 38, 39 on spring-pressed pivoted levers 34, 35 carried by the beam element A ; at the end of the downward movement of the crank, a roller 40 carried by stationary bars 41 forces the levers 34, 35 apart and causes the plate 8 to be released. In a modification, Fig. 4, the spring 12 is replaced by a piston and cylinder 56, and at the end of the downward movement of the driving- crank, a stationary stop 49 engages a spring- pressed valve-rod 50 and causes pressure fluid to be admitted to the cylinder to cause the arms B to be suddenly oscillated.