GB641513A - An improved device for cutting holes in plates, tanks and the like - Google Patents

Abstract

641,513. Cutting discs from sheet metal. COLLIER, A. March 12, 1948, Nos. 7595 and 27394. [Class 83 (iii)] A device for cutting holes in plates, tanks, and the like, of the type in which no clamping means is required behind the plate to be cut, comprises a self-tapping anchor spindle, a body portion or holder in which said spindle is slidably mounted, means for locating a circular cutter on the lower end of the body portion and means for traversing said cutter relatively to said spindle. The spindle 3 is provided at its lower end with a tapered selftapping portion 4 which is entered in a previously drilled hole in the plate 50 to be cut, thus forming an anchor for the further operations of the tool. The upper end of the spindle has a clutch-face-5 which may be brought into engagement with a clutch-face 6 provided in the upper part of the tool and rotatable by means of a tommy-bar 16. A sleeve 2, slidably surrounds the spindle 3 and carries a cutter assembly 9, 12 on its lower portion rotatable with the sleeve but slidable thereon through a key 10 and keyway 11. A further sleeve 8 screwed to the exterior of sleeve 2 and provided with tommy-handles 15 is provided to feed the cutter through the plate. The tool may be driven through the extension 14 by hand or power means. In a modification the clutch device 5, 6 is replaced by a spring- pressed plunger which engages a keyway in the spindle for turning the anchor portion and is withdrawn for cutting the plate. A further modification embodies a hexagon head on the top of the self-tapping anchor portion adapted to be turned by a spanner and incorporates a screwed collar operating through a ball thrust collar for the feed movement.