GB727603A - Rotary drilling machine, more especially a rotary rock-drilling machine - Google Patents

Abstract

727,603. Drilling-machines. SIEMENS SCHUCKERTWERKE AKT.- GES. Sept. 16, 1952 [Nov. 24, 1951], No. 23253/52. Class 83 (3). A drilling-machine, more particularly a rock-drilling machine, is provided with two operating-gear stages, one of the stages transmitting a torque proportional to the bearing-force on the drill in addition to a small constant moment and the other stage transmitting a supplementary moment exceeding this proportional value, so that together, through the two stages, the torque necessary for drilling is transmitted from the spindle to the drilling shaft. The drill 10, Fig. 1, is carried at the end of a rod 9 supported by a bearing 8 on an elongated frame. The drill rod is driven by a shaft 12 through a gear-box 13 from an electricmotor 17 which also drives the feed-screw 14, supported below the drill, and terminating in a thrust bearing and supporting-head 36, 7, respectively. The drive from the motor 17, preferably, passes through a gear-box 15, to the feed-shaft 14 which has a pinion 21, Fig. 3, splined thereto and driving a wheel 22 loose on the drill-shaft 12. A thrust bearing 20 is arranged at the back face of the wheel 22 and a clutch surface 32 at the front face. A long nut 25 on the feed-screw 14 in the gear-box 13 carries an integral pinion 23 which engages with a gear-wheel 24 coaxial with the drill shaft 12. The wheel 24 and a clutch part 31 have quick-pitch threaded bores which engage a threaded part of the shaft 12. An integral extension 19 of the wheel 24 engages a collar in the clutch part 31 and the latter is secured through a torsion spring 30 to a collar 33 secured to the shaft 12. A further collar 26, Figs. 3 and 4, fixed to the portion of the shaft 12 within the gear-box 13 forms part of a unidirectional clutch or brake which prevents reverse rotation of the shaft 12 and is used during the withdrawal motion of the drill, which thus takes place at high speed. The machine provides a differential feed movement in the forward direction dependent upon the resistance to penetration of the drill and a quick return movement on reversal of the driving motor. The return movement is also automatically stopped if the resistance to withdrawal of the drill exceeds a predetermined value.