US 4,630,215 AGranted

Machine tool tracer assembly and control system

OwnerMerrill E. Graham, Jr.inventor

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Abstract

A tracing stylus assembly for controlling operation of an electrically controlled machine tool produces analog electrical signals which are representative of displacement of a stylus member from a center rest position in any direction in at least two transverse planes which correspond to planes of movement available in the machine tool during machining operations. The electrical signals from the tracing stylus are connected to standard motor control amplifiers in the machine tool to control movement of the machine tool. The electrical signals from the stylus may be easily processed to provide adjustments to operation not otherwise possible. For example, the null point of the stylus member can be adjusted electronically as can the correlation between the amount of travel of the stylus and the rate of response of the machine tool. A computer operated machine can be easily programmed using the stylus assembly of the invention, and the stylus assembly can be used as a fail-safe device to automatically halt operations of the machine when under automatic computer control if the control or computer malfunctions so that the machine tool starts to move in a manner that would ruin a part being machined.

A tracing stylus assembly for controlling the operation of an electrically controlled machine tool, comprising a housing adapted to be mounted on a machine tool;

a stylus member mounted in said housing, one end of which extends from the housing and is adapted to be held by a user and manipulated to trace a pattern, the stylus member being movable in said housing in transverse planes which correspond to the transverse planes of relative movement between the material being machined and the machining implement;
means for converting the movement of the stylus member in each plane into electrical signals representative of the amount and direction of movement of the stylus in each plane, such signals being a separate voltage signal for each plane of movement with the polarity of the signal indicating the direction of movement in such plane and the amplitude of the signal indicating the amount of movement;
a first differential amplifier for each plane of movement connected to receive the signals from the stylus representing movement of the stylus in one direction in that plane and to produce an output representative of a difference between that input and a first reference signal;
a second differential amplifier for each plane of movement connected to receive the signals from the stylus representing movement of the stylus in the opposite direction in that plane and to produce an output representative of the difference between that input and a second reference signal;
and a third differential amplifier for each plane of movement connected to produce a signal representative of the difference in the outputs of the first and second differential amplifiers, the output signal from the third differential amplifier being the signal representative of the movement of the stylus in either direction in that plane from its adjusted zero position, adjustment of at least one of the reference signals adjusting the zero output position of the stylus in that plane.

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Facts

Application

06/547,375Filed 31 Oct 1983

Granted

16 Dec 1986

Term ends

Not estimatedThe source records don’t support an estimate.

Classification7 codes

B23Q 35/123
Using mechanical sensing: the feeler varying the impedance in a circuit
G05B 19/4068
Characterised by monitoring or safety: verifying part program on screen, by drawing or other means
G05B 19/4207
Preparation of the program medium using a drawing, a model: in which a model is traced or scanned and corresponding data recorded
G05B 2219/35351
Nc in input of data, input till input file format: while machining probe model, sense drawing by same program, stop if deviation

Abstract

Claims21