Grinding machine

Claim 2

In a machine wherein a tool and a workpiece are moved relatively toward and away from each other to perform a work operation on the workpiece, the combination comprising a first support for the tool, a second support for the work member, a rotatable feed member, one of said supports being connected with said rotatable feed member such that upon rotation of said feed member, said one support is moved relative to the other support, an electric motor connected to said feed member for rotating the same, said motor being of the type which produces a torque that is proportional to the current applied thereto, and an accurate resolution encoder operable to produce a large number of pulse signals for each revolution of the feed member.

Claim 3

The combination set forth in claim 1 wherein said motor is of the permanent magnet DC type.

Claim 4

The combination set forth in claim 1 wherein said feed member comprises a feed screw, said one support which is operatively connected thereto having a nut thereon through which the screw extends, said feed screw being rotatably supported by longitudinally spaced bearings, at least some of said bearings having a preload thereon which functions to prevent rotation of the feed screw upon a load being applied to the one support operatively connected thereto.

Claim 5

The combination set forth in claim 3 including means for applying a constant current to the motor which is sufficient to equal the preload on the feed screw such that additional current applied to the motor will produce a rotation of said feed screw proportional to the additional current.

Claim 6

The combination set forth in claim 1 including hydrostatic support means for said movable support.

Claim 7

The combination set forth in claim 1 wherein said encoder comprises a pulse generator, coupled to the feed member.

Claim 8

The combination set forth in claim 6 wherein said pulse generator comprises an optical type generator.

Claim 9

The combination set forth in claim 6 wherein said pulse generator produces pulses on the order of 20,000 pulses per revolution.

Claim 10

The combination set forth in claim 1 wherein said encoder is of the type such that each pulse is produced by movement of the support on the order of one ten-millionth of an inch.

Claim 11

The combination set forth in claim 1 including a pulse generator for producing a plurality of pulses, and means for converting said pulses to a voltage and applying them to the motor.

Claim 12

The combination set forth in claim 1 including means for applying a predetermined voltage to said motor to rotate the motor and, in turn, move the feed member and the support connected thereto at a predetermined rate, means for comparing the pulses received from the encoder to a predetermined count, and means for terminating the application of voltage to said motor when the pulses from the encoder are equal to the predetermined count.

Claim 13

The combination set forth in claim 1 including means for monitoring the current being applied to the motor, means for comparing said monitored current to a predetermined standard, and means for controlling the current such that it does not exceed the predetermined standard.

Claim 14

The combination set forth in claim 12 including means for comparing the pulse count from the encoder to a predetermined standard, and means for terminating the controlling of current when the pulse count equals the predetermined standard.

Claim 15

The combination set forth in claim 13 including means for applying a predetermined pulse count and a predetermined pulse rate, means for converting said pulse rate to a voltage proportional to the rate and applying the same to the motor, means for initiating the application of said lastmentioned pulse rate at the termination of the controlling of the current, and means for terminating the application of said last-mentioned voltage when the pulse count from the encoder equals the predetermined pulse count.

Claim 16

The combination set forth in claim 1 including counter means for counting the pulses from the encoder and terminating the particular movement upon reaching a predetermined count.

Claim 17

The combination set forth in claim 1 including means for applying a plurality of pulses, voltage control means for converting said pulses to a count and applying them to the motor, and means for comparing the rate of said pulses from the encoder to a predetermined standard rate and permitting the passage of pulses therefrom to the voltage control means only at a predetermined maximum rate not exceeding said standard.

Claim 18

The combination set forth in claim 1 including control means for said motor comprising means for establishing a predetermined pulse rate and predetermined number of counts for each of the portions of desired movement of the support, means for converting each said pulse rate to a voltage, and means for controlling the application of each said voltage to the motor to provide a movement of said one support in each of the predetermined rates and distances corresponding to the predetermined number of counts.

Claim 19

The combination set forth in claim 17 wherein said portions of movement comprise a total feed length, a rapid traverse length.

Claim 20

The combination set forth in claim 18 wherein the total feed length is further divided into fast feed, medium feed and finish feed portions, each of which has means for varying the rate and length thereof.

Claim 21

The combination set forth in claim 18 wherein the total feed is divided into fast feed and finish feed portions, means for limiting the current applied to the motor to a predetermined value during the fast feed portion, and means for limiting the duration of said last-mentioned current applied to the motor, the finish feed portion having means for varying the rate and length of feed of pulses to the means for controlling the motor.

Claim 22

The combination set forth in claim 20 including means for comparing the current applied to the motor to a predetermined standard and means for limiting the current to the motor such that it does not exceed the predetermined standard.

Claim 23

The combination set forth in claim 21 including means responsive to the termination of the fast feed portion for supplying a predetermined rate of pulses during the finish feed portions and means for converting said rate of pulses to a voltage proportional to said rate and applying it to said motor.

Claim 24

The combination set forth in claim 1 including means for measuring the duration of a predetermined portion of the movement of the workpiece, and means responsive to a predetermined change in this duration to produce a signal.

Claim 25

The combination set forth in claim 1 including means for controlling the speed of the workpiece comprising means manually programmable for the diameter and S.F.M. of the workpiece and means responsive to said last-mentioned means for varying the speed of the workpiece such that the workpiece rotates at the predetermined S.F.M.

Claim 26

The combination set forth in claim 1 including means responsive to a predetermined increase of current to the motor upon engagement of the tool with the workpiece to cause a signal changing the rate of movement of the grinding wheel relative to the workpiece.

Claim 27

The combination set forth in claim 25 wherein said engagement of the workpiece is operable to cause means for controlling the current delivered to the motor to become operable.

Claim 28

The combination set forth in claim 1 including means responsive to the revolutions of the workpiece per unit time for controlling the rate of a series of pulses, and means for producing a voltage proportional to the rate of the pulses and applying said voltage to the motor.

Claim 29

The combination set forth in claim 1 including means responsive to the diameter of the workpiece and a predetermined peripheral surface speed of the tool with respect to the workpiece for controlling the speed of rotation of the workpiece to produce said predetermined surface speed.

Claim 30

The combination set forth in claim 1 including means for periodically sensing the time interval for movement of the tool relative to the workpiece through a predetermined distance, means for comparing said time with a predetermined time interval, and means for producing a signal when said sensed time interval exceeds said predetermined time interval.

Claim 31

The combination set forth in claim 1 including means manually programmable for a predetermined desired diameter of the workpiece, a predetermined surface speed per minute and a predetermined number of revolutions of the workpiece for rotating the workpiece for a predetermined number of revolutions.

Claim 32

The combination set forth in claim 1 including means for sensing the time required for the removal of a predetermined amount of material from the workpiece, and means for producing a signal when said time deviates from a predetermined standard by a predetermined percentage.

Claim 33

The combination set forth in claim 1 including means for measuring and storing the time for removal of a first predetermined portion of the workpiece, means thereafter successively measuring the time for removal of an equivalent portion of the workpiece on each successive cycle, and means for producing a signal when said any of said successive times exceeds the first-mentioned time by a predetermined percentage.

Claim 34

In a grinding machine wherein a rotating grinding whEel and a workpiece are moved relatively toward and away from each other to perform a work operation on the workpiece, the combination comprising a first support for the grinding wheel, a second support for the work member, a rotatable feed device, said first support being directly connected with said rotatable feed device such that upon rotation of said feed device, said first support is moved relative to said second support, an electric motor directly connected to said feed device, said motor being of the type which produces a torque that is proportional to the current applied thereto, and an accurate resolution encoder directly connected to the feed member and operable to produce a plurality of signals of predetermined duration for each revolution of the feed member.

Claim 35

In a grinding machine wherein a rotating grinding whEel and a workpiece are moved relatively toward and away from each other to perform a work operation on the workpiece, the combination comprising a first support for the grinding wheel, a second support for the work member, a rotatable feed device, said first support being directly connected with said rotatable feed device such that upon rotation of said feed device, said first support is moved relative to said second support, an electric motor directly connected to said feed device, said motor being of the type which produces a torque that is proportional to the current applied thereto, and an accurate resolution encoder directly connected to the feed member and operable to produce a plurality of signals of predetermined duration for each revolution of the feed member.

Claim 36

The combination set forth in claim 33 wherein said motor is of the permanent magnet DC type.

Claim 37

The combination set forth in claim 33 wherein said feed member comprises a feed screw, said first support which is operatively connected thereto having a nut thereon through which the screw extends, said feed screw being supported by longitudinally spaced bearings, at least some of said bearings having a preload thereon which functions to prevent rotation of the feed screw upon a load being applied to the support connected thereto.

Claim 38

The combination set forth in claim 33 including means for applying a constant current to the motor which is sufficient to equal the preload on the feed screw such that additional current supplied to the motor will produce a rotation of said feed screw proportional to the additional current.

Claim 39

The combination set forth in claim 33 including hydrostatic support means for said movable support.

Claim 40

The combination set forth in claim 33 wherein said encoder comprises a pulse generator, coupled to the feed member.

Claim 41

The combination set forth in claim 38 wherein said pulse generator comprises an optical type generator.

Claim 42

The combination set forth in claim 38 wherein said pulse generator produces pulses on the order of 20,000 pulses per revolution.

Claim 43

The combination set forth in claim 33 wherein said encoder is of the type such that each pulse is produced by movement of the support on the order of one ten-millionth of an inch.

Claim 44

The combination set forth in claim 33 including a pulse generator for producing a plurality of pulses, means for converting said pulses to a voltage applying them to the motor.

Claim 45

The combination set forth in claim 42 including means for reducing the voltage to the motor just prior to contact between the workpiece and the grinding wheel, means for monitoring the current of the motor during a portion of said last-mentioned monitoring, and means for initiating the last succeeding portion of the cycle when the percentage increase in current exceeds a predetermined amount.

Claim 46

The combination set forth in claim 33 including means responsive to a predetermined diameter and predetermined speed for maintaining the relative positions of the workpiece and grinding wheel for a predetermined number of revolutions at the completion of the movement of the grinding wheel and workpiece relative toward one another.

Claim 47

The combination set forth in claim 33 including means for controlling the speed of the workpiece comprising means programmable for the diameter and SFM of the workpiece and means for varying the speed of the workpiece such that the workpiece rotates at the predetermined SFM.

Claim 48

The combination set forth in claim 33 including means responsive to a predetermined increase of current upon engagement of the grinding wheel with the workpiece to cause a signal changing the rate of movement of the grinding wheel toward the workpiece.

Claim 49

The combination set forth in claim 46 wherein said engagement of the workpiece is operable to cause means for controlling the current delivered to the motor to become operable and thereby limit the movement of The grinding wheel toward the workpiece.

Claim 50

In a grinding machine wherein a rotating grinding wheel and a workpiece are moved relatively toward and away from each other to perform a work operation on the workpiece, the combination comprising a first support for the grinding wheel, a second support for the work member, a rotatable feed screw, said first support being connected with said feed screw such that upon rotation of said feed screw, said first support is moved relative to said second support, said support which is operatively connected to the feed screw having a nut thereon through which the screw extends, said feed screw being supported by longitudinally spaced bearings, at least some of said bearings having a preload thereon which functions to prevent rotation of the feed screw upon a load being applied to the support connected thereto, an electric motor connected to said feed screw, said motor being of the type which produces a torque that is proportional to the current applied thereto, and an accurate resolution encoder directly connected to the feed screw operable to produce a plurality of signals of predetermined duration for each revolution of the feed screw, means for controlling the movement of said screw and in turn said workpiece with respect to the grinding wheel through a plurality of portions of a cycle, means for applying a predetermined rate of pulses and a predetermined number of pulses for each such portion, and means for converting each such rate to a voltage and applying it to the motor, means responsive to the angular rate of movement of the workpiece or controlling the rate at which the pulses are converted to a voltage and applied to the motor, said encoder functioning to produce pulses corresponding to the movement between the workpiece and grinding wheel, and means for terminating each portion of the cycle when the predetermined pulse count for each portion equals the pulse count from the encoder.

Claim 51

In a grinding machine wherein a rotating grinding wheel and a workpiece are moved relatively toward and away from each other to perform a work operation on the workpiece, the combination comprising a first support for the grinding wheel, a second support for the work member, a rotatable feed screw, said first support being connected with said feed screw such that upon rotation of said feed screw, said first support is moved relative to said second support, said support which is operatively connected to the feed screw having a nut thereon through which the screw extends, said feed screw being supported by longitudinally spaced bearings, at least some of said bearings having a preload thereon which functions to prevent rotation of the feed screw upon a load being applied to the support connected thereto, an electric motor connected to said feed screw, said motor being of the type which produces a torque that is proportional to the current applied thereto, and an accurate resolution encoder directly connected to the feed screw operable to produce a plurality of signals of predetermined duration for each revolution of the feed screw, means for controlling the movement of said screw and in turn said workpiece with respect to the grinding wheel through a plurality of portions of a cycle, means for applying a predetermined rate of pulses and a predetermined number of pulses for each such portion, and means for converting each such rate to a voltage and applying it to the motor, means responsive to the angular rate of movement of the workpiece or controlling the rate at which the pulses are converted to a voltage and applied to the motor, said encoder functioning to produce pulses corresponding to the movement between the workpiece and grinding wheel, and means for terminating each portion of the cycle when the predetermined pulse count for each portion equals the pulse count from the encoder.

Claim 52

The combination set forth in claim 48 wherein said motor is of the permanent magnet DC type.

Claim 53

The combination set forth in claim 48 including means for applying a constant current to the motor which is sufficient to equal the preload on the feed screw such that additional current supplied to the motor will produce a rotation of said feed screw proportional to the additional current.

Claim 54

The combination set forth in claim 48 including hydrostatic support means for said movable support.

Claim 55

The combination set forth in claim 48 wherein said encoder comprises an optical type generator.

Claim 56

The combination set forth in claim 52 wherein said encoder produces pulses on the order of 20,000 pulses per revolution.

Claim 57

The combination set forth in claim 48 wherein said encoder is of the type such that each pulse is produced by movement of the support on the order of one ten-millionth of an inch.

Claim 58

The combination set forth in claim 48 wherein said portions of movement comprise a total feed length, a rapid traverse length, the latter being further divided into a total feed length.

Claim 59

The combination set forth in claim 55 wherein the total feed length is further divided into fast feed, medium feed and finish feed portions, each of which has means for varying the rate and length thereof.

Claim 60

In a grinding machine wherein a rotating grinding wheel and a workpiece are moved relatively toward and away from each other to perform a work operation on the workpiece, the combination comprising, a first support for the gridnding wheel, a second support for the work member, a rotatable feed device, said first support being directly connected with said feed screw such that upon rotation of said feed screw, said first support is moved relative to said second support, said support which is operatively connected thereto having a nut thereon through which the screw extends, said feed screw being supported by longitudinally spaced bearings, at least some of said bearings having a preload thereon which funcitons to prevent rotation of the feed screw upon a load being applied to the support connected thereto, an electric motor connected to said feed device, said motor being of the type which produces a torque that is proportional to the current applied thereto, and an accurate resolution encoder operable to produce a plurality of signals of predetermined duration for each revolution of the feed screw, means for controlling the movement of said screw and, in turn, said wrkpiece workpiece respect to the grinding wheel through a plurality of portions of a cycle, means for applying a substantially constant current to said motor during one cycle portion for maintaining said workpiece and grinding wheel in contact with a constant force, said encoder functioning to produce pulses corresponding to the movement of the workpiece and the grinding wheel, and means for terminating each portion of the cycle when the predetermined pulse count for each portion equals the pulse count from the encoder.

Claim 61

In a grinding machine wherein a rotating grinding wheel and a workpiece are moved relatively toward and away from each other to perform a work operation on the workpiece, the combination comprising, a first support for the gridnding wheel, a second support for the work member, a rotatable feed device, said first support being directly connected with said feed screw such that upon rotation of said feed screw, said first support is moved relative to said second support, said support which is operatively connected thereto having a nut thereon through which the screw extends, said feed screw being supported by longitudinally spaced bearings, at least some of said bearings having a preload thereon which funcitons to prevent rotation of the feed screw upon a load being applied to the support connected thereto, an electric motor connected to said feed device, said motor being of the type which produces a torque that is proportional to the current applied thereto, and an accurate resolution encoder operable to produce a plurality of signals of predetermined duration for each revolution of the feed screw, means for controlling the movement of said screw and, in turn, said wrkpiece workpiece respect to the grinding wheel through a plurality of portions of a cycle, means for applying a substantially constant current to said motor during one cycle portion for maintaining said workpiece and grinding wheel in contact with a constant force, said encoder functioning to produce pulses corresponding to the movement of the workpiece and the grinding wheel, and means for terminating each portion of the cycle when the predetermined pulse count for each portion equals the pulse count from the encoder.

Claim 62

The combination set forth in claim 57 wherein said motor is of the permanent megnet DC type.

Claim 63

The combination set forth in claim 57 including means for applying a constant current to the motor which is sufficient to equal the preload on the feed screw such that additional current supplied to the motor will produce a rotation of said feed screw proportional to the current.

Claim 64

The combination set forth in claim 57 including hydrostatic support means for said movable support.

Claim 65

The combination set forth in claim 57 wherein said pulse generator comprises an optical type generator.

Claim 66

The combination set forth in claim 61 wherein said pulse generator produces pulses on the order of 20,000 pulses per revolution.

Claim 67

The combination set forth in claim 57 wherein said encoder is of the type such that each pulse is produced by movement of the support on the order of one ten-millionth of an inch.

Claim 68

The combination set forth in claim 57 wherein the total feed is divided into fast feed and finish feed porrions, the fast feed portion controlled by said means for applying a substantially constant current to the motor, the finish feed mode having means for varying the rate and length of feed of pulses to the means for controlling the motor.

Claim 69

The combination set forth in claim 57 including means for controlling the speed of the workpiece comprising measn programmable for the diameter and SFM of the workpiece and means for varying the speed of the workpiece such that the workpiece rotates at the predetermined SFM.

Claim 70

The combination set forth in claim 57 including means responsive to a predetermined increase of current upon engagement of the grinding wheel with the workpiece to cause a signal changing the rate of movement of the grinding wheel toward the workpiece.

Claim 71

The combination set forth in claim 57 wherein said engagement of the workpiece is operable to cause means for controlling the current delivered to the motor to become operable and thereby limit the movement of the grinding wheel toward the workpiece.

Claim 72

The combination set forth in claim 57 including means for sensing the time required for the removal of a predetermined amount of material from the workpiece, and means for producing a signal when said time deviates from a predetermined standard by a predetermined percentage.

Claim 73

The combination set forth in claim 57 including means for measuring and storing the time for removal of a first predetermined portion of the workpiece, means thereafter successively measuring the time for removal of an equivalent amount of the workpiece on each successive cycle, and means for producing a signal when said any of said successive times exceeds the first-mentioned time by a predetermined percentage.

Claim 74

In a grinding machine, the combination comprising a first suppOrt for a grinding wheel, a second support for a workpiece, means for moving said supports relative to one another to bring the workpiece and tool into contact, means for measuring and storing the time grinding a first workpiece, means for thereafter measuring the time for grinding a predetermined equivalent portion of subsequent workpieces, and means for producing a dressing signal when the time for said subsequent grinding exceeds the first mentioned stored time by a predetermined precentage.

Claim 75

In a grinding machine, the combination comprising a first suppOrt for a grinding wheel, a second support for a workpiece, means for moving said supports relative to one another to bring the workpiece and tool into contact, means for measuring and storing the time grinding a first workpiece, means for thereafter measuring the time for grinding a predetermined equivalent portion of subsequent workpieces, and means for producing a dressing signal when the time for said subsequent grinding exceeds the first mentioned stored time by a predetermined precentage.

Claim 76

In a machine tool wherein a tool and a workpiece are moved relatively toward and away from each other to perform a work operation on the workpiece, the combination comprising a first support for the tool, a second support for the workpiece, a rotatable feed device, one of said supports being connected with said rotatable feed device so that upon rotation of said feed device said support is moved relative to the other support, and an electric motor connected to the feed device, means for applying a predetermined voltage to the motor just prior to contact with the workpiece so that the motor operates at constant current, means for monitoring said current, and means for producing a work contact signal when the increase in current due to contact between the workpiece and tool increases by a predetermined amount.

Claim 77

In a machine tool wherein a tool and a workpiece are moved relatively toward and away from each other to perform a work operation on the workpiece, the combination comprising a first support for the tool, a second support for the workpiece, a rotatable feed device, one of said supports being connected with said rotatable feed device so that upon rotation of said feed device said support is moved relative to the other support, and an electric motor connected to the feed device, means for applying a predetermined voltage to the motor just prior to contact with the workpiece so that the motor operates at constant current, means for monitoring said current, and means for producing a work contact signal when the increase in current due to contact between the workpiece and tool increases by a predetermined amount.