GB1248311A - Removing projections from the inside of tubes - Google Patents

Abstract

1,248,311. Grinding. A.P.V. CO. Ltd. 6 Jan., 1970 [13 Jan., 1969], No. 1990/69. Heading B3D. A device for removing projections, such as weld flash, from the inside of a tube 7 comprises a rotor 4, means 18 for rotatably mounting the rotor coaxially within the tube, one or more abrasive elements 14 mounted on the rotor so as to be movable in a radial direction, and resilient means 12 biasing the element or elements towards the axis of the rotor against centrifugal force, and controlling the distance of the element or elements from the axis when the rotor is rotated. As described, the elements are in the form of abrasive pebbles 14 mounted on cups 15 formed with stems 16 radially guided in the rotor 4. The cups are rigidly connected to leafsprings 12 having their ends secured to the rotor by caps 13, the springs urging the abrasive pebbles towards the axis of the rotor. The device is supported in the tube by a pair of seals 18 which are rotatably mounted on the device and act as bearings therefor, the seals containing cutting fluid which is supplied from absorbent material in an annular cup 17 during rotation of the device. A shaft 3, which is adjustable in length by being telescopic or having removable or additional sections is connected to the device and supported by discs 6 in the tube. The outer end of the shaft is connected to the chuck 2 of a variable speed electric motor 1 carried by a plate 19 reciprocated along guides 21 by a crankdrive 28 from a motor 29. The speed of the motor is adjusted so that the centrifugal force acting on the pebbles against the springs 12 causes the pebbles just to engage the tube. The motors are driven intermittently under the control of a timing device 30 to allow cutting fluid to flow to the pebbles. In another embodiment, the cutting fluid is disposed in an-annular reservoir in the device. The tube may be cooled externally by fitting a reservoir of cooling liquid around the tube.