ARRANGEMENT FOR MOUNTING SWING CYLINDERS IN BOOM FOR ROCK DRILLING UNIT

PCT No. PCT/FI95/00458 Sec. 371 Date Feb. 14, 1997 Sec. 102(e) Date Feb. 14, 1997 PCT Filed Aug. 28, 1995 PCT Pub. No. WO96/07014 PCT Pub. Date Mar. 7, 1996An arrangement for mounting swing cylinders in a boom for a rock drilling unit which includes a frame, a boom pivotally connected about vertical and horizontal shafts, relative to the frame, a lift cylinder connected between the frame and the boom, and a swing cylinder connected between the frame and the boom. The unit also includes a support for a feed beam, pivotally connected to the other end of the boom about horizontal and vertical shafts, a tilt cylinder, connected between the support and the boom, and a transverse swing cylinder connected between the support and the boom. The swing cylinder is coupled at an angle ( alpha ), relative to the longitudinal axis of the boom, such that the longitudinal axis of the swing cylinder has a downward inclination from the frame toward the opposite end of the boom, so that with the boom in the middle of its upper and lower angles of altitude, the swing cylinder is essentially horizontal.