GB766145A - Improvements in and relating to surface finishing machines - Google Patents

Abstract

766,145. Polishing surfaces. LUKENS STEEL CO. Nov. 25, 1954, No. 34238/54. Class 60 A machine for finishing the surface of a workpiece comprises a bridge-like structure 9, Fig. 1, mounted for movement in one direction over the surface of the workpiece, a trolley 16 mounted on the structure 9 for movement over the workpiece in a direction transverse to that of this structure, and a yieldable and rotatable tool, e.g. a brush B, carried by the trolley 16 so that it can be moved to and from the workpiece under the control of one mechanism which brings the tool into and out. of engagement with the workpiece - and a second mechanism which adjusts the pressure of engagement of the tool with the workpiece. The trolley 16, Fig. 1, is movable on transverse tracks 13 on the bridge 9 which is movable on longitudinal tracks 7 supported on a concrete foundation 1a. I-beams 1b are embedded in the foundation for supporting metal plates 2 to which the workpiece W is clamped; the upper face of the foundation is shaped to provide a space beneath the plates 2 for housing equipment for circulating coolant. Motors are provided for driving the bridge 9 and trolley 16 on their tracks. The brush is mounted in end bearings 37, 38, Figs. 3 and 4, in two arms 35, 36 which can be swung upwardly and downwardly on bearings 33 on a horizontal shaft 30 rotatably mounted in the trolley 16. The drive of the brush is from a motor on the trolley 16 through a belt drive 28 to the shaft 30 and thence through another belt drive 41 to a pulley 42 coaxial with the shaft 51 carrying the brush. The pulley 42 is keyed to a tubular member 44 which is rotatable in the bearing 38 and secured to a coupling member 45 in which the right-hand end (Fig. 4) of the brush shaft 51 is splined for relative longitudinal movement. The brush is constantly reciprocated axially without affecting its rotation by admitting fluid alternately to opposite ends of a cylinder 58 pivoted on the arm 36; the piston rod of the cylinder is connected to one end of a lever 54 which at its other end is connected to a rod 53 projecting through the tubular member 44 from the shaft 51. Control of the fluid to the cylinder is by means of a solenoid-actuated valve (96, Fig. 12, not shown) arranged to be alternately energized and de-energized by the operation of a motor-driven switch which may be disconnected when no reciprocation of the brush is desired. The mechanism for moving the brush to and from the workpiece comprises a shaft 68 which is rotatable in the trolley 16 by worm gearing 66, 67 operated by a hand-wheel 62 and carries at its ends cranks 71, 72 each connected to the piston rod 77 (or 78) of a fluid pressure cylinder 79 (or 80) pivoted to the corresponding arm 35 or 36; fluid is admitted to one end or the other of the two cylinders 79, 80 to raise or lower the brush from the workpiece under thecontrol of hand-operated valve (95, Fig. 12, not shown). To start a polishing operation, pressure fluid is admitted to the lower ends of the cylinders 79, 80 and exhausted from their upper ends so that the piston rods 77, 78 are extended until abutments on their pistons engage the upper ends of the cylinders and a rigid connection between the piston rods and cylinders is provided. Rotation of the hand-wheel 162 then adjusts the position of the brush to adjust the, polishing pressure. A cross-bar 87 mounted between the arms- 35, 36 limits the upward movement of the brush by engaging, the underside of the trolley 16.