GB1400419A - Drilling and tapping assembly for attachment to a lathe - Google Patents

Abstract

1400419 Drilling and tapping assembly TELCO (GROUP MANAGEMENT) Ltd 15 June 1972 [11 Aug 1971] 37661/71 Headings B3C and B3N An assembly for drilling and tapping a hole in a workpiece 12 mounted in the collet chuck 11 of a lathe is, in use, mounted by casing 1 on lathe cross-slide 10. Initially, drive from, for example a flexible drive coupling see Fig. 1, is transmitted via shaft 17 and pinions 22 and 23 to drill 24 which is fed by the cross-slide to drill the hole. Shaft 17 also drives, via pinions 20, 21, rearward and forward gear and dog clutch members 28 and 33 freely rotatable on shaft 18 which carries tap 9, an axially slidable clutch member 38 connecting either member 28 or 33 to shaft 18 dependent on its position but being initially biased by spring 43, Fig. 2, to connect forward gear member 33 so that the tap is rotated in a withdrawal sense. After drilling, the cross-slide is retracted and supporting structure 75 for the drill 24, shaft 18 and associated parts is pivoted about the axis of the shaft 17 by means of fluid-pressure operated cylinder 45 actuating lever 46 so that the tap is brought to the working position. In so doing, a projecting lower end of a lever 49 mounted on the structure 75 engages cross-slide 10 and pushes a latch 41-connected to clutch member 38 via yoke 40-rearwardly so that gear and clutch member 28 is engaged and the tapping shaft 18 rotates in an insertion sense and is advanced by means of lead screw and nut arrangement 25, 26 on one end. When a predetermined depth of tap is reached an abutment body 48 of shaft 18 engages a plate 52, Figs. 2, 4, carrying a depth indicating rod 55 and a screw-threaded depth adjustment stem 53, which has an abutment 74, and movement of the plate causes abutment 74 to operate tripping lever 51, Fig. 2, to "trip" latch 41, which is pivoted to yoke 40, upwardly and out of engagement with lever 49 thereby allowing spring 43 to return the clutch member 38 to its forward position and to withdraw the tap 9 until clutch member 38 is carried out of engagement with member 33.