Improvements in or relating to drilling machines

摘要

755,518. Drilling-machines. ALLEMANN, H. July 24, 1953 [March 30, 1953], No. 20643/53. Class 83 (3). A drilling-machine comprises a frame 1, Fig. 1, a tool-carrying spindle 4 rotatable in the frame, a work-table 11 to carry work 12 and movable in relation to the tool 22 along the drilling axis, the mounting of the spindle in the frame or the mounting of the work in the table being such that during a stage in the movement of the table from the inoperative to the drilling position, the spindle or work has radial play for aligning the work and tool, which, during subsequent movement and during drilling, are held in alignment. In one embodiment spindle 4 is connected by a square end 41 to a member 2 supported in the frame 1 and driven by means, not shown. The spindle is supported by a bush 6 having play in a part 8 and having radial pegs 7 engaging V-shaped slots 81 in the part. A plate 61, attached to or integral with the bush, has pegs 16 to engage locating-holes 121 in the work 12, which is mounted in a recess in the table 11. The thrust during drilling is taken by a nut 5 on spindle 4 engaging the end 21 of member 2, and a spring-loaded foot 13 presses the work into the recess. Should the drill break, the nut 5 drops and engages an adjustable contact 21 to complete an electric circuit, causing stoppage of the machine. If the pegs do not enter the holes 121 the bush 6 engages an adjustable contact 29, as the table is moved, to complete an electric circuit and stop the machine. In a modification, the pegs 38, Fig. 4, in the plate 39 engage holes in a member 34 which has a recess engaging the upper end of circular work 33, the member being urged by a spring 36 to position the work accurately, the bush 391 then being moved to align the pegs with the holes. In another embodiment, the spindle has no radial play and the work is located in a recess by a bridge-member containing a drilling bush and having a peg to engage a hole in the work and an inclined surface to engage an edge of the work. In a modification, pegs 55, Fig. 7, in a member 56 fixed to the frame engage holes in adjustablymounted work 51. Plate 52 serves to strip the work from the pegs after drilling.