GB626655A - Improvements in and relating to hydraulic means for feeding a tool spindle - Google Patents

Abstract

626,655. Drilling long holes. LE MAIRE TOOL & MANUFACTURING CO., LEGG, W. C., and HARDING, L. V. July 30, 1946, No. 22644. [Class 83 (iii)] [Also in Group XXIX] A machine-tool, for feeding a rotating tool 27 intermittently at a constant rate, comprises a fixed main housing 10 containing a telescopic housing 23 which carries a rotary toolspindle 20 and which is extended and retracted by hydraulic means, means controlled by the movement of the spindle for intermittently applying hydraulic pressure to the telescopic housing during a predetermined interval in its extension, and hydraulic means for effecting a rapid return of the housing at the end of the interval. The spindle 20 is rotatably mounted in a piston 34 sliding in a cylinder 35 and is rotated by a motor 11 driving through gears 14, 15 and a female splined member 106. The member 106 incorporates a rotary valve 54, Fig. 6, which controls the supply of intermittent feed pressure. Drilling is commenced by pressing a button 86, Fig. 9, which actuates a solenoid 89 and a 4-way valve 51 so that an hydraulic motor 13, Figs. 3 and 9, supplies pressure, via lines 62, 65, a valve 72 and lines 68, 66 and 67, directly to the piston 34. Intermittent feed commences when a cam-rod 75, which is mounted on a flange 93 on the piston 34, actuates the valve 72 to close line 65 so that pressure is supplied only through lines 62, 64 and the rotary valve 54, a relief valve 50 being actuated when the valve 54 is closed. As break-through commences, a compensating valve 53 in the discharge line 79 maintains a back-pressure in a line 69 and prevents a jump of the drill. At the end of the stroke, an adjustable dog on an arm, also attached to the flange 93, trips a switch 91 to cut-out the solenoid 89 and reverse the valve 51 to supply pressure via both lines 59 and 60. At the completion of the cycle a spring-pressed plungervalve 111, Fig. 3, enters a recess 112 in the piston 34 and connects a port 121 to exhaust at 71, thus allowing the pump 13 to idle. The valve 106 may be modified to vary the flow during feed or to provide more than one pressure feed during one revolution, or only one pressure feed during several revolutions, of the spindle 20. The rear casing of the drill unit forms an oil reservoir 41. A sight gauge is provided in the casing to check the fluid level in the chamber 45.