Feedrate numerical control contouring machine including means to provide excess feedrate

Claim 2

In a numerical control machine tool system of the type wherein a feedrate generator output drives a contour generator, the output of which is applied to drive a motor, said feedrate generator and said contour generator each including a digital differential integrator having an integrand register, an accumulator register, and an adder for adding the contents of said integrand register and accumulator register as they are entered into said adder least significant bit first, said integrand register contents being circulated back therein and there being a means for entering the sum from said adder into said accumulator register most significant bit end, means for entering a feedrate number into said feedrate integrand register means for entering an axis command number into said contour generator integrand register, the improvement comprising: means for determining when a zero bit following a most significant one bit in a binary number in said feedrate integrand register is being applied to said adder and prOviding an output signal representative thereof, means for deriving an overflow bit from said feedrate adder responsive to said output signal, means responsive to said overflow bit for causing said contour generator digital differential integrator to go through an iteration cycle responsive thereto, a shift register having a predetermined bit capacity, means operative a predetermined time after the occurrence of said output signal for entering bits from the output of said contour generator adder into said shift register up to its bit capacity instead of entering them into said contour generator accumulator, means for shifting out the contents of said shift register as an overflow output before it receives another output from said contour generator adder, and means for utilizing the overflow output of said shift register for driving said motor.

Claim 3

In a numerical control machine tool system as recited in claim 1 wherein said means for determining when a zero bit following a most significant one bit in a binary number in said integrand register is being applied to said adder and providing an output signal representative thereof includes a first counter means having a count capacity equal to the bit capacity of said integrand register, means operative while said integrand register circulates its contents for advancing the count in said first counter means by one for each zero bit and resetting said first counter means to zero for each one bit to count the number of leading zeros in the binary number in said integrand register, means for advancing the count by one in said first counter means as each bit in the number in said integrand register is being applied least significant bit first to said adder, and means for providing said output signal when said first counter means overflows.

Claim 4

In a numerical control machine tool system as recited in claim 2 wherein said means operative a predetermined time after said overflow bit is derived from said adder includes a second counter means having a count capacity equal to the bit capacity of said integrand register, means for entering the complement of the count in said first counter means into said second counter means, means for advancing the count by 1 of said second counter means as each binary bit in said contour generator integrand and accumulator registers are entered into said adder to be added starting with least significant bits first, and means operative when said second counter means has attained a predetermined count to enter bits from said adder into said shift register instead of into said contour generator accumulator.

Claim 5

In a numerical control machine tool as recited in claim 1 wherein said means for utilizing the output of the shift register for driving said motor includes: a down counter shift register, means for entering into said downcounter shift register said axis command number while it is being entered into said contour generator integrand register, and means for applying said overflow output of said shift register to drive said motor while reducing the number in said downcount shift register by said overflow output.

Claim 6

In a numerical control system as recited in claim 1 wherein a rapid traverse operation is desired, means for replacing the binary number in said feedrate generator integrand register with a rapid traverse code number, means responsive to said code number for generating an output signal at a predetermined time after said rapid traverse code number is commenced to be entered into said feedrate generator adder, counter means responsive to said rapid traverse code and said output signal to establish a count therein of the number of leading zeros in the command number in said contour generator integrand register, means to advance the count of said counter means in synchronism with the recirculation of the number in said integrand register during iteration of said contour generator, means responsive to a predetermined count of said counter means for enabling said means for entering bits into said register from said contour generator adder instead of into its accumulator register.

Claim 7

In a numerical control machine tool system of the type wherein a feedrate generator output drives a contour generator for each axis of motion, the output of which drives a motor for each axis of motion, said feedrate generator and said contour generator for each axis each comprising a digital differential integrator, each having an integrand register, an accumulator register, an adder for adding the contents of said integrand and accumulator registers as they are entered therein least significant bit first, said integrand register contents being circulated back therein, means for entering the sum from said adder into the accumulator register most significant bit position, means for entering a feedrate number into said feedrate integrand register, and means for entering an axis command number into each said contour generator integrand register, the improvement comprising: means for determining when a zero bit following a most significant one bit in the number in said feedrate generator integrand register is being applied to its adder and producing an indicative output signal, means for deriving an overflow bit from said adder responsive to said output signal, means responsive to said overflow bit for causing said contour generators for each axis to go through an iteration cycle responsive thereto, a shift register for each axis having a predetermined capacity, means for each contour generator operative a predetermined time after said output signal for entering bits from the output of each axis contour generator adder into such axis shift register up to its capacity instead of into each axis contour generator accumulator, means for shifting the contents of each axis register out as an overflow output before a succeeding output is received from the contour generator adder, means for applying each axis overflow output to drive each axis motor, means for storing each axis command number, means for decrementing each stored axis command number by the overflow output applied to drive each axis motor, and means to specify a new axis command number or terminate operation when the stored axis command number reaches zero.

Claim 8

In a numerical control machine tool system of the type wherein a feedrate generator output drives a contour generator for each axis of motion, the output of which drives a motor for each axis of motion, said feedrate generator and said contour generator for each axis each comprising a digital differential integrator, each having an integrand register, an accumulator register, an adder for adding the contents of said integrand and accumulator registers as they are entered therein least significant bit first, said integrand register contents being circulated back therein, means for entering the sum from said adder into the accumulator register most significant bit position, means for entering a feedrate number into said feedrate integrand register, and means for entering an axis command number into each said contour generator integrand register, the improvement comprising: means for determining when a zero bit following a most significant one bit in the number in said feedrate generator integrand register is being applied to its adder and producing an indicative output signal, means for deriving an overflow bit from said adder responsive to said output signal, means responsive to said overflow bit for causing said contour generators for each axis to go through an iteration cycle responsive thereto, a shift register for each axis having a predetermined capacity, means for each contour generator operative a predetermined time after said output signal for entering bits from the output of each axis contour generator adder into such axis shift register up to its capacity instead of into each axis contour generator accumulator, means for shifting the contents of each axis register out as an overflow output before a succeeding output is received from the contour generator adder, means for applying each axis overflow output to drive each axis motor, means for storing each axis command number, means for decrementing each stored axis command number by the overflow output applied to drive each axis motor, and means to specify a new axis command number or terminate operation when the stored axis command number reaches zero.

Claim 9

In a numerical control system as recited in claim 6 wherein for circular interpolation there is included: means for generating the two''s complement of the overflow output from one axis, means for adding said two''s complemented overflow output to the number in the contour generator integrand register of another axis, and means for subtracting the overflow output of said another axis from the number in the contour generator integrand axis of said one axis.

Claim 10

In a numerical control system as recited in claim 6 wherein said means for determining when a zero bit following a most significant one bit in the number in said feedrate generator integrand register is being applied to its adder and producing an indicative output signal includes, a first counter means having a count capacity equal to the bit capacity of said integrand register, means operative while said integrand register circulates its contents for advancing the count in said first counter means by one for each zero bit and resetting said first counter means to zero for each one bit in said number in said integrand register to count the number of leading zeros in said number, means for advancing the count by one in said first counter means as each bit in the number in said integrand register is being applied least significant bit first to said feedrate generator adder, and means for providing an output signal when said first contour means overflows.

Claim 11

In a numerical control machine tool system as recited in claim 8 wherein said means operative a predetermined time after said overflow bit is derived from said adder includes a second counter means having a count capacity equal to the bit capacity of said integrand register, means for entering the complement of the count in said first counter means into said second counter means, means for advancing the count by 1 of said second counter means as each binary bit in said contour generator integrand and accumulator registers are entered into said adder to be added starting with least significant bits first, and means operative when said second counter means has attained a predetermined count to enter bits from said adder into said shift register instead of into said contour generator accumulator.

Claim 12

In a numerical control system as recited in claim 5 wherein a rapid traverse operation is desired, means for replacing the binary number in said feedrate generator integrand register with a rapid traverse code number, means responsive to said code number for generating an output signal at a predetermined count of said first counter means, means responsive to said rapid traverse code number for enabling said second counter means to count the number of leading zeros after the most significant bit in the largest of the axis command numbers, means to thereafter advance the count of said second counter means in synchronism with the recirculation of the number in each of the axis contour generator integrand registers during iteration of said contour generators, and means operative when said second counter means has reached a predetermined count to enable said means for each contour generator for entering bits into the respective contour generator shift registers from the respective adders instead of into the respective accumulator registers.