Patent GB-413102-A (GB)
Title: Hydraulic arm translating means for radial drills
IPC: B23Q1/30
Filed: 1933-05-16
Abstract: 413,102. Drilling-machines. CINCINNATI BICKFORD TOOL CO., Cincinnati, Ohio, U.S.A. May 16, 1933, No. 14185. Convention date, July 26, 1932. [Class 83 (iii).] In a radial-arm drilling- machine, the arm is moved vertically on the column sleeve by fluid pressure and the clamps for securing the arm to the sleeve, and the sleeve to the column, are also operated by fluid pressure. The column sleeve S, Fig. 2, is split by a T-shaped slot at 7 and is clamped by a bolt 9 attached to an eccentric sheave 10 operated by an eccentric 12 on a vertical shaft 11. The bolt 9 may be rotated by a hand lever 8, or for clamping by power, the shaft 11 is rotated by a pinion and rack 13, 14, Fig. 6, the rack being reciprocated by a pinion 15 operated by rack teeth 17<a> on a hydraulic piston 17. A pump F, Fig. 2, is driven by gearing f from the longitudinal shaft 3 on the radial arm G which is itself driven by an electric motor on the arm and serves to drive the spindle in the drill head H, Fig. 4. The pump draws oil from a reservoir R in the arm and delivers it to a valve 37, Figs. 2 and 6, which is controlled by a hand lever 37<h> and linkage 37e, Fig. 4, to supply the piston 17 at one end or the other through pipes 57, 64. When the piston 17 has moved to either of its extreme positions, the oil continues to pass through one of the pipes 61, 65, the valve 37 and a pipe 63 to one of the valves 38, 39 which respectively control the arm clamp and arm elevating cylinder. A valve 60, operated by a port 58 in the cylinder 17<c>, ensures the passage of oil from the right hand end of the cylinder 17<c> to the pipe 63. A lever 47, Fig. 4, is connected by a linkage 44 to a crosshead 40, Figs. 2 and 6, which unites the two valves 38, 39, the lever being biassed to a neutral position by a spring plunger 49 so that the arm clamp is normally applied and the arm elevating cylinder inoperative. The valve 38 first admits oil to one end or the other of a cylinder 20b, by means of the pipes 66, 68, thereby moving a piston 20 having rack teeth which drive a pinion 22 carrying an eccentric 24. A roller 25 surrounds the eccentric 24 and acts on a plunger 26 carrying an equalizing head 27 engaging the free ends of levers 18, 19 fulcrummed at 18a, 19a, Fig. 2, and pivoted to bolts 18<c> 19<c>, passing through ears 18b, 19<b> on each side of a vertical split g in the arm G. Upward movement of the lever 47 places the valves 38, 39 in the position shown in Fig. 6, the oil passing from the pipe 63 to the left hand end of the cylinder 20b and moving the piston 20 to unclamp the arm G. When the piston 20 has reached the limit of its travel oil passes by the pipe 67 to the valve 39 and thence by the pipe 35 to the top of a cylinder 32 secured to the arm G and having a piston 34 secured to a lug 35<x> on the column sleeve S. The arm G is then raised until the operator releases the lever 47, whereupon the lever returns to the neutral position, the arm is held due to the pipes 35, 36 leading from the elevating cylinder 32 being closed by the pistons 39<y>, 39<z >of the valve 39, and the clamp is again closed by oil passing through a pipe 71 to the valve 39 and thence by a pipe 75, 68 to the right hand end of the cylinder 20. When the piston 20 has reached its limit at the left, oil passes by a port 76 to a valve 78 which is thereby opened to connect the pipe 68 to exhaust through pipes 79, 80. For lowering the arm G, the lever 47 is moved downwards and oil is admitted from the valve 39, by the pipe 36, to the lower end of the cylinder 32. When the arm clamp has been applied, the pump discharges freely to the sump R through the cylinder 20b.