Computer numerical control machine tool

• US 4,199,814 A
• Filed: 10/12/1977
• Issued: 04/22/1980
• Est. Priority Date: 10/12/1977
• Status: Expired due to Term

• Current Assignee: AMAF Industries, Inc.
• Original Assignee: Digitcom, Inc.
• Inventors: Rapp, Edward J., Johnson, Glen A.
• Primary Examiner(s): Ruggiero, Joseph F.
• Application Number:
  US05/841,597
• Time in Patent Office: 923 Days
• Field of Search: 364/474, 364/475, 364/107, 364/114, 364/115, 364/120, 364/200 MS File, 364/900 MS File, 318/568, 318/569, 318/570, 318/572, 318/573, 318/571, 318/574, 318/685, 318/696
• US Class Current: 700/180
• CPC Class Codes: G05B 19/4093 characterised by part programming, e.g. entry of geometrical information as taken from a technical drawing, combining this with machining and material information to obtain control information, named part programme, for the NC machine
• CPC Class Codes: G05B 19/41 characterised by interpolation, e.g. the computation of intermediate points between programmed end points to define the path to be followed and the rate of travel along that path G05B19/25, G05B19/31, G05B19/37, G05B19/39, G05B19/40 take precedence
• CPC Class Codes: G05B 19/4141 characterised by a controller or microprocessor per axis
• CPC Class Codes: G05B 2219/34215 Microprocessor
• CPC Class Codes: G05B 2219/35282 Verify if loaded program into memory or stored into tape, cassette is correct
• CPC Class Codes: G05B 2219/35426 Prepare, enter next program during execution of actual program, machining
• CPC Class Codes: G05B 2219/35471 Select between run and step command mode, step forward, reverse
• CPC Class Codes: G05B 2219/35472 Mode selection
• CPC Class Codes: G05B 2219/35556 Conversion inch to metric
• CPC Class Codes: G05B 2219/36074 Display part, select, mark element and edit corresponding block
• CPC Class Codes: G05B 2219/36111 Local memory instead of tape, or combined
• CPC Class Codes: G05B 2219/36554 Copy modified, corrected program to another tape, keep original intact
• CPC Class Codes: G05B 2219/36556 Compare, check orignal tape with converted, copy tape
• CPC Class Codes: G05B 2219/49395 Repeating same operations for other coordinates
• CPC Class Codes: G05B 2219/50195 Emergency stop stops drives and spindle, stored program remains in memory
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]

Abstract

This invention relates to a computer numerical control (CNC) machine tool system having a novel terminal controller and system therefor to control a machine tool generally with at least two axes and more probably three, with stepping motor controls for point-to-point positioning of the machine tool to an almost infinite variety of steps (generally not more than 200). The novelty resides in the ease of programming directly on the terminal controller of the CNC machine tool system. Generally at least some editing and offsets will be programmed from the machine tool.

The terminal controller consists of a microprocessor with some RAM and ROM, together with address and data bus plus I/O for magnetic tape handling and display for 6 to 8 digits in each of the X and Y positions, together with numeric keyboard for data input to the program steps and functional keys to control operation-automatic, manual and step-by-step, as well as controls for program input from tape to memory and memory to tape.

Particular features include the ease of inputting a program and preparing a tape and then editing the tape while in operation. Further features include circular and linear interpolation. For circular interpolation there are no quadrant limitations and a full or partial circle may be cut.

Claims

1. In a computer numerical control for point-to-point positioning and programming of a machine tool on at least two axes, said control being physically adjacent and electrically connected to the machine tool and having programming and control functions for said machine tool, said control comprising:

(a) an input terminal having a keyboard with alpha-numeric input plus functional control keys;

(b) disply means for showing the position of the machine tool at any time in X and Y coordinates, and having a display means which may be selectively used to output position number, tool number, and feed rate information;

(c) a microprocessor having an arithmetic logic unit, a CPU, RAM and ROM store and data and address handling means;

(d) a cassette tape input means with control logic therefor to input a computer program into store and to tape a program in store; and

(e) control means including functional keys for causing the stored program to direct and control the machine tool together with other control means for inputting into store, machine language instructions directly on the terminal, thereby modifying a stored program or building one.

2. The computer numerical control of claim 1 in which the entire program is entered into store directly on the control through the terminal and checked on the display for X and Y positions as the steps of the program are performed.

3. The computer numerical control of claim 1 in which a number of offsets are programmed into the program and the machine tool is run with those offsets and stored on tape for reuse.

4. The computer numerical control of claim 1 in which the program has stored coordinates, i.e., X and Y, plus speed of travel for a machine operation and a control program in the machine regulates the acceleration and deceleration of the drive depending on the inertia of the machine, distance to travel and other factors and provides direct control to the machine without other interface equipment.

5. The computer numerical control of claim 1 in which the coordinates of any number of steps can be recalled for use in a subsequent programming step with another tool without reprogramming the coordinates of the new positions.

6. In a computer numerical control for point-to-point positioning of a machine tool on at least two axes comprising:

(a) an input terminal having a keyboard with alpha-numeric input plus functional keys;

(b) display means for showing the position of the machine tool at any time in X and Y coordinates, and having a display means which may be selectively used to output position number, tool number, and feed rate information;

(c) cassette tape input means;

(d) a microprocessor having an arithmetic logic unit, a CPU, RAM and ROM, and data and address handling means;

(e) means for controlling the microprocessor through the keyboard to input to RAM, X and Y coordinates of positions for machining in addition to speed of travel between positions;

(f) means for converting the input data from English or metric units to machine language for storage in direct control of the X and Y axes of the machine tool; and

(g) means for reconverting the machine language store to English or metric units for program checking or control.

7. The computer numerical control of claim 6, in which the entire program is entered into the control in either English or metric units, converted to machine language for controlling the machine tool and then retrieved for display on command in either unit by reconversion.

8. In a computer numerical control for point-to-point positioning of a machine tool on at least two axes, a circular interpolation means comprising:

(a) an input terminal having a keyboard with alpha-numeric input plus functional keys;

(b) display means for both X and Y axes;

(c) cassette tape input means;

(d) microprocessor having an arithmetic logic unit,

a CPU, RAM and ROM, and data and address handling means;

(e) means for controlling the microprocessor through the keyboard to input to RAM, X and Y coordinates of positions for machining in addition to speed of travel between positions;

(f) means for storing coordinates of a circular interpolation routine in the form of

(1) a starting coordinate in X and Y data,

(2) center coordinates in X and Y data,

(3) end point coordinates in X and Y data,

(4) clockwise or counterclockwise movement;

(g) means for calculating the position of the circular interpolation over an infinite number of discrete points without regard to quadrants;

(h) calculating means to locate the tool at these discrete points; and

(j) comparison means to compare the calculated position with the actual position to guide the machine tool in a continuous path radius compensation.