GB1306941A - Machine for machining internal surfaces of workpieces - Google Patents

Abstract

1306941 Grinding LESLIE HARTRIDGE Ltd 24 July 1970 [24 July 1969] 37246/69 Heading B3D A machine for lapping, remachining, reconditioning and internal surfaces 20 of workpieces, such as fuel injection atomized nozzles or wire drawing dies 19, comprises means 22 for holding a workpiece, means 16 on the end of a machine spindle 1 to hold a tool 17, the tool and holder being relatively movable towards and away from each other, and means 9, 39 associated with the spindle for applying intermittently variable axial pressure to the tool in a direction towards the holder for the workholder during revolutions of the machine spindle without lifting the tool out of contact with the workpiece. The spindle is mounted for rotation and axial movement in bearings 2, 3 in plates 4, 5 which are carried by uprights 26, 31 and form a box on which a motor 7 is mounted having a belt drive 8 to a pulley 9 on the spindle. The lower end of the spindle carries the holder 16 for the tool for machining the workpiece 19 which is held by a block 22 on a plate 23 fitted with a tank 30 for cutting liquid into which the tool can be dipped to impregnate its abrasive surface. The plate 23 is vertically adjustable by a screw device 29. The upper surface of the pulley 9 is formed with one or more radial steps 47, Fig. 4, and is engaged by a roller 39 rotatably mounted on a plate 40 carried by a rod 41 which is guided in bearings 42, 43 in the plates 4, 5 and supports a weight 46. As the spindle 1 rotates the steps 47 react against the pulley 39 and weight to intermittently vary the pressure of the tool against the workpiece and may effect a hammer-like top. In other embodiments, the pulley is flat and the roller is formed with the steps or is eccentric, or a solenoid acts on the weight to vary the pressure. The machine may have one or a plurality of spindles.