GB582763A - Improvements in or relating to drilling machines - Google Patents

Abstract

582,763. Drilling diamonds. DEFENSE SUPPLIES CORPORATION. Nov. 29, 1943, No. 19943. Convention date, Oct. 12, 1942. [Class 83 (iii)] A diamond drilling-machine comprises a number of units secured to a vertical panel 11 with a flanged base 12, each unit having a vertical drill spindle 2 and an aligned work-holding rod 3 on which the diamond is carried, in the usual mounting provided for use in a wire-drawing machine. The rod 3 is counterbalanced by a thread 30, with a spring or like resilient member 48, to act as shock-absorber on impact of the diamond and drill-wire 1, and passing over a pulley 33 to suspend a container 35 for shot. The bar is held by the thread, due to its inclination, against spaced pairs of upper'and lower rollers 38 mounted on centre bearings on bracket 90 adjustable laterally in two directions at right angles by a nut and screw 100 and by screws 102 to secure parallelism to, and correct alignment with, the drill spindle. A rapid reciprocation of small amplitude is iinparted by an eccentric 42 on a shaft 43, belt-driven at 56 from a countershaft 58 that also drives the drill spindle at 21 and is driven at 24 from a pulley 25 on the motor shaft. The eccentric acts on a lever 40 pivoted on centres at 41 engaging screws in a block 60 vertically adjustable, to apply feed to the diamond holder, on rods supported in the base and in a bracket 62. One of the rods is threaded to provide for movement by a knob 65. The short end of the lever has pivoted to it an offset block 50 held in place by a leaf spring 52 and carrying an arm 45 acting on a pin on the rod 3 to depress it in opposition to the pull of the thread 30. In a modification, the eccentric 42 acts through a T-piece 73, Fig. 12, on a rock-shaft 74, that acts on the lever 40 mounted to swing in a horizontal plane and having at its shorter end a screw 79 that presses against a normally flexed spring 80 having a pad 83 of leather or rubber &c. that presses against the rod to move it downwards. The spindle is mounted in upper and lower ball bearings contained in housings 104 separated by a cylindrical shell 116 having an opening for the belt and carrying a brake pad adjusted by a screw 120 to regulate the spindle speed. A second brake pad, carried by a rod 124 that can be pressed in against a spring, provides for stopping the spindle when required. Oil supplied from a container 110 screwed into the upper housing 104 passes through the bearing and is thrown by a collar to a recess drained by a port connected at 105 to the lower bearing which is similarly lubricated and delivers to a pipe 108 leading to a filter 109. The action of the drill wire may be observed by a microscope 128, Fig. 14, mounted in a frame 129 having a member 136 carrying depending'rods 137 that can be received in holes in a bar 140 adjustably supported in the lower housing 104. The frame 129 is supported further by a rod 131 engaging a recess in the top of an adjusting screw 133. The microscope can be shifted as required from one drill unit to another.