Patent GB-969868-A (GB)
Title: Tube polisher
IPC: B24B23/06
Filed: 1961-12-04
Abstract: 969,868. Polishing. HI-SHEAR CORPORATION. Dec. 4, 1961 [Dec. 27. 1960], No. 43299/61. Heading B3D. A tube polisher includes a rotatable drive plate and a drive gear which are relatively rotatable, an intermediate gear and a Spindle gear journalied to the drive plate, all of said gears and the drive plate having parallel axes of rotation, the intermediate gear being meshed with the spindle gear and the drive gear, a spindle connected to and driven by the spindle gear, whereby rotation of the drive plate rotates the spindle axes around the drive plate axis and relative rotation of the drive gear and the drive plate turns the spindle on its own axis, a closing arm freely journaled to the drive plate and having a free weighted portion spaced from its journalled point adapted to swing outwardly from the central axis when the drive plate is rotated, a rotatable swing arm assembly journalled to the drive plate including an arm-portion engaged to the closing arm, and a support arm adapted to be moved arcuately toward the axis of the drive plate when the closing armis swung outwardly therefrom, abrasive means including a polishing surface parallel to said axes mounted to and driven by said spindle, said polishing surface also being mounted to said support arm whereby rotation of the swing arm assembly selectively moves the polishing surface toward and away from the central axis of the device, and a pilot assembly mounted to said drive plate so disposed and arranged to enter a tube whose outer surface is to be  polished by the polishing surface to hold the same in alignment therewith. A polisher is driven by a hand-held air motor 11 having a handle 12, an off-on switch button 13, a frame connection 14 and a drive shaft 15. The polisher has a cover 16 to protect the user from the moving parts and a grip 17 by which the greater part of the weight of the polisher can be supported. A drive gear 22 is threadedly mounted on the frame connection `14. A drive plate 24 is attached to the drive shaft 15 and carries a stud 32 on which is a gear 31 meshing with the gear 22 and with a spindle gear 33 on a spindle 34. The latter is mounted by bearings 35, 38 in a support 39 secured to the drive plate 24. A pulley 37 is secured to the, end of the spindle 34. An abrasive belt passes round pulley 37 and round an idler pulley 41 mounted on a swing arm 42 held to the support 39 by a retaining ring 45. The arm 42 has a sleeve 46 freely rotatable on the support 39 and having an extension 47 provided at its end with a pin 49. The latter engages a slot 50 in a closing arm 53 journalled to a support 55 which corresponds to support 39 and carrying at its free end a weight 54 Swing arm 47 carries a pin 52 extending into the path of the closing arm 53. Two belts are provided, each having driving and mounting means as described above. A coil spring 57 interconnects the two swing arms so that when the polisher is not rotating the idler pulleys are at maximum distance from the polisher axis. When the polisher rotates the weights move outward causing the idler pulleys to move towards the polisher axis, the movement being limited by engagement of the closing arms with the pins 52 on the swing arms. A base plate 25 secured to the drive plate 24 by bolts 26 has tack-welded thereto a tube 27 having an insert 28 to which is threaded a rotatable pilot 29 which enters the tube 30 to be polished. In use, the pilot is inserted in the tube, the motor 11 is started, and the polisher is reciprocated to polish the outside end of the tube for a short distance. The device can be used for polishing off corrosion from the end portions of heat exchanger tubes.