Method and apparatus for feedrate control of spindle-related numerical control systems

Claim 3

A method as defined in claim 1 wherein said first, second and product signals are waveforms having pulses and the values of said first, second and product signals are pulse repetition rates thereof, and said step of varying the rate at which pulses are delivered to said mechanism comprises metering a number of pulses of said product signal to said mechanism for each of said axes equal to corresponding numerically programmed data.

Claim 4

A method as defined in claim 2 wherein said desired vectorial velocity is programmed in units per revolution of said spindle.

Claim 5

In apparatus for controlling the tool traverse velocity of a machine having means for producing relative rotary motion between a cutting tool and a workpiece, and means for moving said tool linearly relative to said workpiece in a plurality of directions orthogonal to each other, said linear motions being commanded in specified distances along said directions while said rotary motion is continued without interruptions, the combiNation comprising: means for producing a continuous pulse train having a pulse rate proportional to angular velocity of said rotary motion; means for receiving in digital form a desired modal velocity value of said tool relative to said workpiece in units of linear motion per revolution of said rotary motion; means for producing in digital form a vectorial value proportional to the vectorial sum of motions called for by commanded linear motions along said orthogonal directions; means for multiplying said continuous pulse train by said modal velocity value and said vectorial value to produce a feedrate pulse train having a pulse rate proportional to the ratio of said modal velocity to the vectorial sum of motions called for by commanded linear motions; and means responsive to said feedrate pulse trains for producing a set of pulse trains, one train for each direction of commanded linear motion, a given train having a number of pulses proportional to the distance of motion commanded in a given direction.

Claim 6

In apparatus for controlling the tool traverse velocity of a machine having means for producing relative rotary motion between a cutting tool and a workpiece, and means for moving said tool linearly relative to said workpiece in a plurality of directions orthogonal to each other, said linear motions being commanded in specified distances along said directions while said rotary motion is continued without interruptions, the combiNation comprising: means for producing a continuous pulse train having a pulse rate proportional to angular velocity of said rotary motion; means for receiving in digital form a desired modal velocity value of said tool relative to said workpiece in units of linear motion per revolution of said rotary motion; means for producing in digital form a vectorial value proportional to the vectorial sum of motions called for by commanded linear motions along said orthogonal directions; means for multiplying said continuous pulse train by said modal velocity value and said vectorial value to produce a feedrate pulse train having a pulse rate proportional to the ratio of said modal velocity to the vectorial sum of motions called for by commanded linear motions; and means responsive to said feedrate pulse trains for producing a set of pulse trains, one train for each direction of commanded linear motion, a given train having a number of pulses proportional to the distance of motion commanded in a given direction.

Claim 7

The combination of claim 4 wherein said vectorial value proportional to the vectorial sum of motions called for by commanded linear motions along said orthogonal directions is equal to the reciprocal of said vectorial sum of motions, and said multiplying means comprising two cascaded pulse-rate-multiplying means, one for multiplying by said modal velocity value and one for multiplying by said vectorial value.

Claim 8

The combination of claim 4 wherein said vectorial value proportional to the vectorial sum of motions called for by commanded linear motions along said orthogonal directions is equal to the vectorial sum, and said multiplying means comprises: means responsive to said modal velocity value and said vectorial value for producing in a digital form a feedrate equal to the ratio of said modal velocity value to said vectorial sum; and a pluse-rate-multiplying means for multiplying said continuous pulse train by said feedrate number.

Claim 9

In a numerical control system for a machine having a spindle for producing relative rotary motion between a tool and a workpiece in response to programmed departures and modal velocities expressed in terms of linear distance per revolution, the combination comprising: means for numerically programming relative linear motions between said spindle and said tool along a plurality of axes during successive machine cycles; means for computing a value proportional to the linear distance said tool must travel during a given machine cycle in response to said programmed departures, said distance being the vectorial sum of vectors defined by said programmed departures along predetermined axes; means for producing a basic train of pulses at a rate proportional to the angular velocity of said spindle; means for computing a feedrate number equal to a ratio of programmed modal velocity to said linear distance said tool must travel during a given machine cycle; means for multiplying the rate of said basic train of pulses by said feedrate number to produce a train of feedrate pulses; and means responsive to said train of feedrate pulses from said multiplying means for establishing the period of said given machine cycle in proportion to the frequency of said feedrate pulses, and for simultaneously metering out a number of said feedrate pulses for each of said axes of motion proportional to programmed linear motion data for respective ones of said axes.

Claim 10

In a numerical control system for a machine having a spindle for producing relative rotary motion between a tool and a workpiece in response to programmed departures and modal velocities expressed in terms of linear distance per revolution, the combination comprising: means for numerically programming relative linear motions between said spindle and said tool along a plurality of axes during successive machine cycles; means for computing a value proportional to the linear distance said tool must travel during a given machine cycle in response to said programmed departures, said distance being the vectorial sum of vectors defined by said programmed departures along predetermined axes; means for producing a basic train of pulses at a rate proportional to the angular velocity of said spindle; means for computing a feedrate number equal to a ratio of programmed modal velocity to said linear distance said tool must travel during a given machine cycle; means for multiplying the rate of said basic train of pulses by said feedrate number to produce a train of feedrate pulses; and means responsive to said train of feedrate pulses from said multiplying means for establishing the period of said given machine cycle in proportion to the frequency of said feedrate pulses, and for simultaneously metering out a number of said feedrate pulses for each of said axes of motion proportional to programmed linear motion data for respective ones of said axes.

Claim 11

In apparatus for controlling the relative tool traverse velocity of a machine having a spindle, said machine having a mechanism which moves a tool in a plurality of orthogonal directions relative to a workpiece in incremental steps, a step in a direction along a given axis being made in response to a pulse received to command motion in that direction, the combination comprising: means for generating a first signal having a value proportional to angular velocity of said spindle; means for generating a second signal havIng a value proportional to a ratio of desired vectorial velocity of said mechanism to the vectorial distance said mechanism is to move in response to programmed motions along said axes; means for multiplying said first and second signals to obtain a product signal proportional to both angular velocity of said spindle and said ratio; and means for varying the rate at which pulses are delivered to said mechanism in accordance with the value of said product signal.

Claim 12

In apparatus for controlling the relative tool traverse velocity of a machine having a spindle, said machine having a mechanism which moves a tool in a plurality of orthogonal directions relative to a workpiece in incremental steps, a step in a direction along a given axis being made in response to a pulse received to command motion in that direction, the combination comprising: means for generating a first signal having a value proportional to angular velocity of said spindle; means for generating a second signal havIng a value proportional to a ratio of desired vectorial velocity of said mechanism to the vectorial distance said mechanism is to move in response to programmed motions along said axes; means for multiplying said first and second signals to obtain a product signal proportional to both angular velocity of said spindle and said ratio; and means for varying the rate at which pulses are delivered to said mechanism in accordance with the value of said product signal.

Claim 13

The combination as defined in claim 8 wherein said first, second and product signals are waveforms having pulses and the values of said first, second and product signals are pulse-repetition rates thereof, and said means for varying the rate at which pulses are delivered to said mechanism comprises means for metering a number of pulses of said product signal to said mechanism for each of said axes equal to corresponding numerically programmed data.

Claim 14

The combination as defined in claim 9 wherein said desired vectorial velocity is programmed in units per revolution of said spindle.