Method of machining a flat harness using a punching machine

1. A method of machining a flat harness, the flat harness including at least three conductor portions, which extend in a longitudinal direction and are aligned in parallel, and insulating portions arranged between adjacent conductor portions of the at least three conductor portions, the method comprising:

providing a punching machine that includes a first punching device and a second punching device that are separately provided and independently controllable, the first and second punching devices each including a punch and a die;

punching a first hole portion on each of the insulating portions arranged between the adjacent conductor portions of the at least three conductor portions of the flat harness in a die cutting process by moving one of the punch and the die of the first punching device in a first direction perpendicular to the longitudinal direction; and

punching a second hole portion on each of the insulating portions arranged between the adjacent conductor portions of the at least three conductor portions of the flat harness in the die cutting process by moving one of the punch and the die of the second punching device in the first direction;

wherein the method of punching the flat harness is performed by

moving at least one of the second punching device and the flat harness in the longitudinal direction and relative to each other between the punching of each first hole portion and the punching of each second hole portion respectively by a predetermined distance in the longitudinal direction, said predetermined distance being variable and selected such that the second punching device is at a position relative to the flat harness so that the punch of the second punching device is aligned to overlap or abut each respective first hole portion, wherein the punching of each second hole portion forms a third hole portion on each of the insulating portions, each third hole portion having a length larger than that of the respective first hole portion on each respective insulating portion of the flat harness, and

wherein the punching of the first hole portion on one of the insulating portions is displaced by a level difference in the longitudinal direction from the punching of the first hole portion on another one of the insulating portions such that a distal end of the third hole portion formed by the first hole portion on said one of said insulating portions is displaced in the longitudinal direction relative to a distal end of the third hole portion formed on said another one of the insulating portions.

2. The method according to claim 1 , wherein for punching one of the first hole portions, the punch of the first punching device is a first punch, and the first punching device further comprises a second punch that is differently shaped relative to the first punch; and

wherein the punching of the one first hole portion is performed by the first punch of the first punching device, and

further comprising punching a fourth hole portion using the second punch of the first punching device,

wherein the punching of the one first hole portion and the punching of the fourth hole portion are performed simultaneously by the first punching device in the die cutting process.

3. The method according to claim 2 , wherein the predetermined distance is selected such that the position of the second punching device is selected so that the punch of the second punching device is aligned to overlap the fourth hole portion to form the third hole portion.

4. The method according to claim 3 , wherein a width of the fourth hole portion is less than or equal to a width of the corresponding second hole portion.

5. The method according to claim 2 ,

wherein the one first hole portion has a near end distal to the fourth hole portion and a far end proximal to the fourth hole portion, and

wherein the fourth hole portion is spaced from the far end of the one first hole portion, and a distance from the far end of the one first hole portion to a far end of the fourth hole portion is less than or equal to a length of the punch of the second punching die;

whereby the fourth hole portion is eliminated as a result of punching of the corresponding second hole portion.

6. The method according to claim 1 , wherein the position of the second punching device is selected so that the punch of the second punching device is aligned to overlap the respective first hole portion.