Numerically controlled process and machine operating according to the process

Claim 2

A numerically controlled process for processing a workpiece (2,12) characterised by the steps of: inputting first data representing the shape of said workplace before processing; comparing the data representing said inputted shape with further data representing a desired working path (ℓ 1 ,ℓ 2 ,ℓ 3 ,ℓ 4 ) of a tool (5) as determined on the basis of a desired finished shape (6) of said workpiece to determine whether said tool is outside said shape or inside thereof when it is on said working path; and moving said tool at a relatively high speed when said tool is outside said shape.

Claim 3

A numerically controlled process for processing a workpiece characterised by the steps of: (a) inputting first data representing the shape of said workpiece (2,12) before machining; (b) inputting further data representing a desired finished shape (6) of said workpiece; (c) determining a working path (ℓ 1 ,ℓ 2 ,ℓ 3 ,ℓ 4 ) for a tool (5) on the basis of said finished shape; (d) comparing said first data with said working path to obtain a point or points (P 1 , P 2 , P 3 , P 4 ) of intersection therebetween; (e) determining whether a working start point (Q 1 ,Q 2 , Q 3 ,Q 4 ) is outside the shape of the workpiece when said point or points of intersection exist; (f) setting a first tool feed speed at a first value when said working start point exists outside said work shape; and setting the first tool feed speed to a lower valuc when said working start point exists inside said workpiece shape; and (g) switching the tool feed speed alternately between said first value and said lower value every time said tool reaches a said point of intersection.

Claim 4

A numerically controlled process for processing a workpiece characterised by the steps of: (a) inputting first data representing the shape of said workpiece (2,12) before machining; (b) inputting further data representing a desired finished shape (6) of said workpiece; (c) determining a working path (ℓ 1 ,ℓ 2 ,ℓ 3 ,ℓ 4 ) for a tool (5) on the basis of said finished shape; (d) comparing said first data with said working path to obtain a point or points (P 1 , P 2 , P 3 , P 4 ) of intersection therebetween; (e) determining whether a working start point (Q 1 ,Q 2 , Q 3 ,Q 4 ) is outside the shape of the workpiece when said point or points of intersection exist; (f) setting a first tool feed speed at a first value when said working start point exists outside said work shape; and setting the first tool feed speed to a lower valuc when said working start point exists inside said workpiece shape; and (g) switching the tool feed speed alternately between said first value and said lower value every time said tool reaches a said point of intersection.

Claim 5

A process according to claim 1 or 2 characterised in that both said first data and said further data are inputted as information representing the form of line segments and/or circular arcs representing the shape from the start point to the end point of each of said workpiece shape and said finished shape.

Claim 6

A process according to any one of the preceding claims, characterised in that said working path of said tool is calculated on the basis of said finished shape, a cutting start point, and an amount of cut.

Claim 7

A process according to claim 2 characterised in that said point or points of intersection between said workpiece shape before machining and said working path is obtained by determining whether an X-coordinate value of the cutting position intersects said work shape before machining.

Claim 8

A process according to claim 5 characterised in that the determination as to whether the tool is outside said workpiece shape or not is made on the basis of whether the tool is at the (+) side or the (-) side, in the X-direction, relative to said workpiece shape.

Claim 9

A numerically controlled processing machine arranged to operate to process a workpiece according to any one of the preceding claims.