GB589556A - Improvements in or relating to brake drum lathes - Google Patents

Abstract

589,556. Portable turning-apparatus. BARRETT, H. B., and BARRETT CO., Ltd., H. B. Aug. 31, 1944, No. 16607. [Class 83 (iii)] [Also in Group XXIII] A lathe for operations on brake drums, including turning and grinding, comprises the combination of a track-way, a carriage disposed on the track-way, a lathe head mounted on and movable with the carriage, an arbor mounted in the lathe head adapted at one end to be secured to the work, and a tool mounted for rotary movement on the arbor, actuating means being carried by the head to produce relative longitudinal motion between the arbor and the lathe head, and means for detachably securing the carriage in a selected location' on the trackway. A pair of wheels W with brake drums d are placed between the rails 1 of the machine and the wheel hub is fastened by the cones 44, 44' to a non-rotating arbor 42 projecting from the machine head. The crank handle 26 is rotated to bring the verticallyadjustable tool-head of the machine into alignment with the wheels prior to the trueing operation. A tool 118 mounted on an arm 117 at right angles to an adjustable square-section arm 106, rotates around the arbor and relative axial movement between tool and work is effected by axial feed of the arbor 42 either by hand or by an electric motor 27 which rotates the tool. The tool-holding member 51, Fig. 8, is rotatably mounted in the casing C and is rotated through spur gears 64, 65 from the motor 27. A worm 46 rotating with the toolholder drives a cross-shaft 89, Fig. 9, with a friction coupling at its outer end enabling a worm 88<1> to be selectively rotated either by the hand wheel 87 or by the power means. The worm 88<1> is geared to a worm-wheel on a vertical shaft which has a pinion at its lower end engaging rack teeth 41<1> cut on the end of the arbor remote from the work. The tool bar 117 may be replaced by an attachment with an electric motor and grinding-wheel g, Fig. 17. A balance weight is then used at the other end of the arm 106 and the motor is supplied by current through a slip ring 71 adjacent the casing C, control of the motor being effected from a rheostat 32. The machine is normally traversed along the rails 1 to position it, but may be held at one end by a catch 6 when a hub and brake drum without tyres are supported by the arbor 42.