Method and apparatus for controlling a machine tool

Claim 1

An apparatus for controlling a cutting tool in which a workpiece and said cutting tool are mounted in a machine tool assembly and one of said workpiece and cutting tool is moved with respect to the other to cause said cutting tool to cut into said workpiece, comprising first means operatively connected to said cutting tool for measuring its cutting force on the workpiece, transducer means coupled to said first means for producing a first electric signal, a signal shaping network receiving said first electric signal and converting it into a second electric signal related to the desired position of said cutting toOl, second means operatively connected to said cutting tool for detecting the actual position of said tool and converting such actual position into a third electric signal, a summing junction adapted to receive and combine said second and third electric signals into a fourth electric signal, and a driver operatively connected to said tool and actuated by said fourth electric signal to move said cutting tool with respect to said workpiece to maintain said workpiece and cutting tool in predetermined spatial relationships during the cutting operation irrespective of any vibrating movements of said workpiece or machine tool assembly.

Claim 2

An apparatus for controlling a cutting tool in which a workpiece and said cutting tool are mounted in a machine tool assembly and one of said workpiece and cutting tool is moved with respect to the other to cause said cutting tool to cut into said workpiece, comprising first means operatively connected to said cutting tool for measuring its cutting force on the workpiece, transducer means coupled to said first means for producing a first electric signal, a signal shaping network receiving said first electric signal and converting it into a second electric signal related to the desired position of said cutting toOl, second means operatively connected to said cutting tool for detecting the actual position of said tool and converting such actual position into a third electric signal, a summing junction adapted to receive and combine said second and third electric signals into a fourth electric signal, and a driver operatively connected to said tool and actuated by said fourth electric signal to move said cutting tool with respect to said workpiece to maintain said workpiece and cutting tool in predetermined spatial relationships during the cutting operation irrespective of any vibrating movements of said workpiece or machine tool assembly.

Claim 4

An apparatus for controlling a cutting tool in which a workpiece and said cutting tool are mounted in a machine tool assembly and one of said workpiece and cutting tool is moved with respect to the other to cause said cutting tool to cut into said workpiece, comprising a strain gage operatively connected to said cutting tool for measuring its cutting force, a transducer coupled to said strain gage and a signal shaping network, said transducer and signal shaping network producing a first electrical signal adapted to serve as a reference signal for the desired position of said tool, a second transducer operatively connected to said tool adapted to produce a second electrical signal in response to the position of said tool, a summing junction connected to said signal shaping network and second transducer for combining said first and second electrical signals, and a servo motor operatively connected to said tool and controlled by a servo valve actuated by the signal from said summing junction, said servo motor moving said tool with respect to said workpiece to maintain said cutting tool and workpiece in predetermined spatial relationships during the cutting operation irrespective of any vibratory movements of said workpiece or machine tool assembly.

Claim 5

An apparatus for controlling a cutting tool in which a workpiece and said cutting tool are mounted in a machine tool assembly and one of said workpiece and cutting tool is moved with respect to the other to cause said cutting tool to cut into said workpiece, comprising a strain gage operatively connected to said cutting tool for measuring its cutting force, a transducer coupled to said strain gage and a signal shaping network, said transducer and signal shaping network producing a first electrical signal adapted to serve as a reference signal for the desired position of said tool, a second transducer operatively connected to said tool adapted to produce a second electrical signal in response to the position of said tool, a summing junction connected to said signal shaping network and second transducer for combining said first and second electrical signals, and a servo motor operatively connected to said tool and controlled by a servo valve actuated by the signal from said summing junction, said servo motor moving said tool with respect to said workpiece to maintain said cutting tool and workpiece in predetermined spatial relationships during the cutting operation irrespective of any vibratory movements of said workpiece or machine tool assembly.

Claim 6

An apparatus for controlling a cutting tool in which a workpiece and said cutting tool are mounted in a machine tool assembly and one of said workpiece and cutting tool is moved with respect to the other to cause said cutting tool to cut into said workpiece, comprising first means operatively connected to said tool for measuring its cutting force on the workpiece, means coupled to said first means producing a first electric signal adapted to serve as a reference signal for the desired position of said cutting tool, second means operatively connected to said cutting tool for detecting the actual position of said cutting tool and converting said position into a second electric signal, means for combining said first and second signals to produce a resultant signal, and a driver operatively connected to said tool and actuated by said resultant signal to move said tool with respect to the workpiece to maintain said cutting tool and workpiece in predetermined spatial relationships irrespective of any vibratory movements of said workpiece or machine tool assembly.

Claim 7

An apparatus for controlling a cutting tool in which a workpiece and said cutting tool are mounted in a machine tool assembly and one of said workpiece and cutting tool is moved with respect to the other to cause said cutting tool to cut into said workpiece, comprising first means operatively connected to said tool for measuring its cutting force on the workpiece, means coupled to said first means producing a first electric signal adapted to serve as a reference signal for the desired position of said cutting tool, second means operatively connected to said cutting tool for detecting the actual position of said cutting tool and converting said position into a second electric signal, means for combining said first and second signals to produce a resultant signal, and a driver operatively connected to said tool and actuated by said resultant signal to move said tool with respect to the workpiece to maintain said cutting tool and workpiece in predetermined spatial relationships irrespective of any vibratory movements of said workpiece or machine tool assembly.

Claim 8

An apparatus for controlling a cutting tool in which a workpiece and said cutting tool are mounted in a machine tool assembly and one of said workpiece and cutting tool is moved with respect to the other to cause said cutting tool to cut into said workpiece, comprising first sensing means operatively connected to the cutting tool for measuring its cutting force on the work-piece, means coupled to said first sensing means for converting the measurement of said cutting force into a first electrical signal related to the desired position of said cutting tool, second sensing means operatively connected to the cutting tool for detecting the actual position of said cutting tool and converting such actual posiTion into a second electrical signal, means for combining said first and second electrical signals into a resultant signal, and a driver operatively connected to said cutting tool and actuated by said resultant signal to move said cutting tool with respect to said workpiece to maintain said workpiece and cutting tool in predetermined spatial relationships during the cutting operation irrespective of any vibrating movements of said workpiece or machine tool assembly.

Claim 9

An apparatus for controlling a cutting tool in which a workpiece and said cutting tool are mounted in a machine tool assembly and one of said workpiece and cutting tool is moved with respect to the other to cause said cutting tool to cut into said workpiece, comprising first sensing means operatively connected to the cutting tool for measuring its cutting force on the work-piece, means coupled to said first sensing means for converting the measurement of said cutting force into a first electrical signal related to the desired position of said cutting tool, second sensing means operatively connected to the cutting tool for detecting the actual position of said cutting tool and converting such actual posiTion into a second electrical signal, means for combining said first and second electrical signals into a resultant signal, and a driver operatively connected to said cutting tool and actuated by said resultant signal to move said cutting tool with respect to said workpiece to maintain said workpiece and cutting tool in predetermined spatial relationships during the cutting operation irrespective of any vibrating movements of said workpiece or machine tool assembly.

Claim 10

A method of controlling the operation of a cutting tool on a workpiece, comprising the steps of mounting said workpiece in a machine tool assembly in a position to permit said cutting tool to engage said workpiece and with a spaced distance between a pair of reference points on said cutting tool and workpiece, coupling at least one of said workpiece and cutting tool to a first driving member for effecting a first relative movement therebetween whereby said cutting tool will perform the desired work on said workpiece at their interface, continuously detecting the force exerted on the workpiece by the cutting tool at their interface, converting said force into a first response signal related to the desired position of said tool, continuously detecting the position of the cutting tool and converting said position into a second response signal, combining said first and second signals and imposing the resultant signal on a second driving member to actuate said second driving member, said first and second signals being continuously and instantaneously generated and combined to provide a continuous and instantaneous resultant signal, and coupling said second driving member to one of said workpiece or cutting tool for effecting a second relative movement therebetween to maintain said reference points at predetermined spaced distances from each other during said work.

Claim 11

A method of controlling the operation of a cutting tool on a workpiece, comprising the steps of mounting said workpiece in a machine tool assembly in a position to permit said cutting tool to engage said workpiece and with a spaced distance between a pair of reference points on said cutting tool and workpiece, coupling at least one of said workpiece and cutting tool to a first driving member for effecting a first relative movement therebetween whereby said cutting tool will perform the desired work on said workpiece at their interface, continuously detecting the force exerted on the workpiece by the cutting tool at their interface, converting said force into a first response signal related to the desired position of said tool, continuously detecting the position of the cutting tool and converting said position into a second response signal, combining said first and second signals and imposing the resultant signal on a second driving member to actuate said second driving member, said first and second signals being continuously and instantaneously generated and combined to provide a continuous and instantaneous resultant signal, and coupling said second driving member to one of said workpiece or cutting tool for effecting a second relative movement therebetween to maintain said reference points at predetermined spaced distances from each other during said work.

Claim 12

A method of controlling the operation of a cutting tool on a workpiece, comprising the steps of mounting said workpiece and cutting tool in a machine tool assembly in a position to permit said cutting tool to exert a cutting force on said workpiece at their interface, coupling at least one of said workpiece and cutting tool to a first driving member for effecting a first relative movement therebetween whereby said cutting tool will perform the desired work on said workpiece at their interface, continuously detecting said cutting force and converting it into a first electric signal related to the desired position of the cutting tool, continuously detecting and converting the position of said cutting tool into a second electric signal, continously combining said first and second signals to produce a third electrical signal, and imposing said third electrical signal on a second driving member to actuate said second driving member, and coupling said second driving member to one of said workpiece or cutting tool for effecting a second relative movement therebetween to maintain predetermined spatial relationships between said workpiece and cutting tool of any vibrating movements of said workpiece or assembly.

Claim 13

A method of controlling the operation of a cutting tool on a workpiece, comprising the steps of mounting said workpiece and cutting tool in a machine tool assembly in a position to permit said cutting tool to exert a cutting force on said workpiece at their interface, coupling at least one of said workpiece and cutting tool to a first driving member for effecting a first relative movement therebetween whereby said cutting tool will perform the desired work on said workpiece at their interface, continuously detecting said cutting force and converting it into a first electric signal related to the desired position of the cutting tool, continuously detecting and converting the position of said cutting tool into a second electric signal, continously combining said first and second signals to produce a third electrical signal, and imposing said third electrical signal on a second driving member to actuate said second driving member, and coupling said second driving member to one of said workpiece or cutting tool for effecting a second relative movement therebetween to maintain predetermined spatial relationships between said workpiece and cutting tool of any vibrating movements of said workpiece or assembly.