GB754144A - Improvements in or relating to boring machines - Google Patents

Abstract

754,144. Boring-machines. ASPBUND, A J. A., [trading as MASKINFIRMA R. L. CARLSTEDT]. Feb. 22, 1954 [Feb. 20, 1953], No. 5096/54. Class 83 (3). A boring - machine, particularly for long bores, has a workspindle driven by an electric motor and a clamping slide, movable along the machine bed, with means for forcing the work against the spindle, a contactor device in the circuits of the said motor and a motor supplying coolant to the tool being adjustable to close the circuits to the two motors only when it is located opposite and in contact with an abutment on the clamping slide. The work 14, Figs. 1 and 2, is rotated by a driving- head 15 from a main electric motor 13 and is held against the head by a clamping slide 18 moved by a compressed air piston and cylinder. The work is held in an offset position relative to the top slide 16 to facilitate loading. The clamping slide, and similarly the slide 20 carrying the boring tool, are guided on the bed 10, Fig. 3, by four faces 16, 28, 32, 34, to support the offset arrangement of the work clamp 70 &c., Fig. 3, and each slide has an anchor portion 42 which is initially adjusted and secured to the top guideway by a dovetailed plate 24 and clamping bolts 26. The tubular boring-tool 74, Figs. 1 and 2, through which the cuttings &c. are discharged at the outlet 118, is secured to the slide 20 which is fed by an hydraulic piston and cylinder from a self-contained electrically-driven pump (see below). The boring bit 78, Fig. 5. is carried at the end of the tubular part 74 and is guided by the freely-rotatable sleeve 68 of the workclamping member. The latter is carried in a cone 64 secured to a freely-rotatable sleeve 58 in the offset portion 54 of the clamping-slide 18. The boring tool is sealed against the escape of pressure coolant by a gland at the rear of the portion 54 and a synthetic gland 90 also acts to damp vibrations. The coolant is led into the tool through a pipe 80 from an electric coolantmotor and pump 79 and passes to the cutting part through a clearance 82, returning with the cuttings through the tubular part 74. A packing ring 84 presses against the end of the work to prevent the escape of coolant. Controls.-A control panel 132, Fig. 2, has buttons 142, 144 for the forward and reverse motion of the clamping-head 18. The compressed-air control circuit for this part includes a pressure-gauge and switch which, if the pressure falls below a predetermined value, automatically stops the main motor and the coolant motor. A knob 212 on the panel 132 starts the hydraulic feed of the tool-slide 20 and a knob 192, with a pointer, adjusts the speed of the feed movement. A stop 292, Fig. 2, limits the forward feed and the slide automatically reverses. The feed is also automatically regulated by valve means according to the resistance of the tool and work. Stops along the bed control the working cycle which normally includes: (a) on approach of tool to the work, switching on of the coolant motor, (b) switching on of the work-driving motor, and (c) after completion of cutting, stoppage of the work-motor. The tool-slide then reverses and before leaving the work on the return, the coolant motor is switched off. A safety contactor device 176, Fig. 4, cuts off the work and coolant motors through switches 178, 180, respectively, if the clamping-slide over-runs when no, work is present. The contactor device is adjustable along the bed and is positioned opposite the point the clamping-head normally contacts the work and an abutment 174 secured to the clamping-slide 18 engages the contactor device to operate it if the slide over-runs. Spebification 753,366 is referred to.