GB622021A - Improvements in or relating to boring tools - Google Patents

Abstract

622,021. Grinding and polishing. HENDERSON, A. S. March 3,1947, Nos. 5997 and 27281. [Class 60] [Also in Group XXII] A tool for boring cylinders comprises a tubular carrier and locating member A adapted to be attached at one end in centred relation to the end of the cylindrical part B to be bored, a detachable tubular guide C adapted to be fixed in the outer end of the carrier, an operating bar F which can slide in the axial direction and be rotated within the guide member by manual or other power, one or more tools mounted in the end of the bar, and means for automatically feeding the bar in the axial directions as it is rotated. The tool may be located by means of a cylindrical body having a frusto-conical end which is adapted to engage both the carrier A and the cylindrical part being bored; in this aligned position, the carrier A is bolted to the work. The guide member C is provided with a flange C<SP>1</SP> which rests in an annular recess A<SP>2</SP> in the carrier and the two members are connected by bolts A'. The operating bar F is rotated by a hand-crank P through bevel gears R, G and is journalled at its upper end in a plate L on which is mounted a gear train to drive a lead screw N in threaded engagement with a nut D secured in the guide member. The plate L also supports a guide rod 2 free to slide in the guide member. The gear train which rotatably couples the lead screw with the operating bar comprises a shaft O<SP>2</SP>, Fig. 6, displaceable in a slot in the plate L so that the lead screw may be rotated by the handcrank P to withdraw the tool from the work at the end of the operation. Alternatively, the nut may be made in two parts so that it can be disengaged from the lead screw. The polishing head, Fig. 8, carries two strips of abrasive material which are wrapped around the outer surfaces of two spring members S, T, each of which comprises two curved plates, such as T, T<SP>1</SP>, between the ends of which the abrasive material is clamped. The polishing head may be replaced by cutters (see Group XXII), and the guide rod 2 by a second lead screw. In an alternative construction, the lead screws are secured to the plate L and the nuts rotated. Change gears may be provided to enable the operating bar to be rotated at a higher speed without increasing the rotational speed of the power source and a higher rate of feed obtained by using lead screws of greater pitch.