Patent GB-1143833-A (GB)
IPC: B24B49/00
Abstract: 1,143,833. Grinding. R. HAISCH. 29 April, 1966, No. 18902/66. Heading B3D. A method of correcting for variations of size and angular relation between a workpiece to be ground and a tool comprises gauging at least two axially spaced points on the workpiece to register variations from a predetermined value in size and angular relationship, respectively, between the tool and workpiece, converting the registered variations to a signal, and translating the signal into automatic correction of the variations. As described, the workpiece is a crankchaft 9 mounted between a headstock 6 and tailstock 8 for rotation about an axis B-B on a table S for grinding by wheels 11<SP>1</SP>, 11<SP>11</SP> ,  11<SP>111</SP>, 11<SP>1111</SP> rotated about an axis C-C by a belt drive 13<SP>1</SP>, 13<SP>11</SP> from a motor 12. Axially spaced portions of the crankshaft are measured by indicators 14<SP>1</SP>, 14<SP>11</SP>. The diameter measured by one of the indicators controls the operation of the machine through a connection V from a control device 15 which also acts on any difference of the diameters detected by the indicators to operate one or other of a pair of magnets 2<SP>1</SP>, 2<SP>11</SP> to selectively move a pawl 3<SP>1</SP> or 3<SP>11</SP> into engagement with a ratchet wheel connected to a cam 1<SP>1</SP> which is disposed between the machine bed and headstock 6 and when rotated elastically deforms the head to adjust the axis B-B so that it is parallel or at the predetermined angular relationship relative to axis C-C. The indicator 14<SP>11</SP> comprises a pair of inductive coils 24<SP>1</SP>, 24<SP>11</SP>, Fig. 4 which respond to movement of a sensing pin 21<SP>1</SP> and are connected into respective bridges 25, 25<SP>1</SP>, and the indicator 14<SP>1</SP> has a single inductive coil 24 connected into bridge 25<SP>1</SP>. The bridge 25<SP>1</SP> is connected to an indicating instrument 28<SP>1</SP> connected by relays and switches to the magnets 2<SP>1</SP>, 2<SP>11</SP> for effecting rotation of the cam. If the output from the bridge 25<SP>1</SP> is such as to indicate a difference in the diameters measured by the indicators 14<SP>1</SP>, 1411 but a pointer 30<SP>1</SP> remains between marks 29<SP>11</SP>, 29<SP>111</SP>, a pilot light 31<SP>1</SP> is energized. If the difference in diameters is such that the pointer moves beyond one or other of the marks 29<SP>11</SP>, 29<SP>111</SP>, the associated light 31, 31<SP>11</SP> and switches and relays are energized to cause repeated actuation of the respective magnet 2<SP>1</SP> or 211 to effect correction. The output from the bridge 25 corresponds to the diameter measured by the indicator 14<SP>11</SP> and its output is connected to an indicating instrument 28 connected to relays 32<SP>11</SP>, 32<SP>111</SP> which control the relays of the indicating instrument 28<SP>1</SP> so that correction is only effective when the pointer 30 of instrument 28 is between marks 29, 29<SP>1</SP> corresponding to a size only slightly above the final size of the workpiece, correction thus not being effective during coarse or the final grinding. The indicators have jaws 17, 17<SP>1</SP>, Fig. 6, which are urged together by a spring 18 so that pins 16, 16<SP>1</SP> contact the workpiece and are supported by spring blades 19 from a holder 18<SP>1</SP>. In other embodiments, the pawls 3<SP>1</SP>, 3<SP>11</SP> are movable by hydraulic or pneumatic motors, to rotate the cam, or the cam is mounted on the shaft of a reversible motor controlled from the instrument 28<SP>1</SP>. In a further embodiment, the headstock 6, Fig. 9, is adjusted by a threaded spindle 104<SP>2</SP> rotated by a worm wheel 102<SP>2</SP> driven by a motor 103<SP>2</SP>. The correction may be applied to the headstock or tailstock, the table S, or to at least one bearing for the grinding wheels, and the correction may be effected by sliding movement rather than by deformation.