1. In a process to cut a sheet material using a laser, the improvement comprising:
performing a first plurality of routings using a first toolpath for the laser; and
performing at least a second routing using a second toolpath for the laser after performing the first plurality of routings using the first toolpath, the second toolpath traverse from a kerf formed by the laser as a result of performing the first plurality of routings.
2. The process of claim 1 wherein the laser is a CO2 laser.
3. The process of claim 1 wherein a pulse of the laser is a rectangular pulse having a rise time of less than 1 micrometer.
4. The process of claim 1 wherein the sheet material comprises polycarbonate.
5. The process of claim 1, further comprising:
determining a shift of the second toolpath relative to the first toothpath.
6. The process of claim 1 wherein the second toolpath includes a z-height shift from the first toolpath
7. The process of claim 1 wherein performing the first plurality of routings occurs in a linear region of material removal.
8. The process of claim 7, further comprising:
determining a number of routings for the first plurality of routings.
9. The process of claim 8 wherein determining the number of routings comprises:
determining the linear region of the material removal by experimentation; and
selecting the number of routings based on the experimentation.
10. The process of claim 8 wherein determining the number of routings comprises:
performing at least three routings using the first toolpath on a sample of the sheet material; and
selecting one of the at least three routings as the number of routings.
11. The process of claim 1 wherein performing at least a second routing comprises performing a plurality of second routing using the second toolpath for the laser after performing the first plurality of routings.
12. The process of claim 1, further comprising:
performing at least a third routing using a third toolpath for the laser after performing the at least the second routing, the third toolpath including a z-height shift from the first toolpath.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A spark plug comprising:
a center electrode;
a ground electrode forming a spark gap between the center electrode and the ground electrode;
an insulator having an intermediate trunk portion, a rear trunk portion provided rearwards of the intermediate trunk portion, and an axial hole extending along an axis of the insulator, the insulator holding the center electrode within the axial hole at the front end thereof; and
a metallic shell accommodating the intermediate trunk portion of the insulator and having a crimp portion at the rear end thereof,
wherein the intermediate trunk portion of the insulator includes:
a shoulder portion pressed forward by means of the crimp portion,
a maximum diameter portion disposed frontward of the shoulder portion and having a maximum outer diameter among those portions constituting the intermediate trunk portion, and
an intermediate diameter portion connecting the shoulder portion and the maximum diameter portion, having a smaller diameter than the maximum diameter portion, and having a groove portion extending at least in a circumferential direction on an outer surface of the intermediate diameter portion, and
wherein a glaze layer covers a surface of the insulator extending from a rear trunk portion to a portion located between the shoulder portion and the groove portion.
2. The spark plug as claimed in claim 1, wherein the surface of the insulator is exposed so as not to be covered by the glaze layer at the maximum diameter portion.
3. The spark plug as claimed in claim 1, wherein the difference in radius between the maximum diameter portion and the intermediate diameter portion is equal to or greater than 0.05 mm but not greater than 0. 15 mm.
4. The spark plug as claimed in claim 1, wherein the intermediate diameter portion has an axial length equal to or greater than 2.0 mm.
5. A spark plug comprising:
a center electrode;
a ground electrode forming a spark gap between the center electrode and the ground electrode;
an insulator having an intermediate trunk portion, a rear trunk portion positioned rearwards of the intermediate trunk portion and covered with a glaze layer, and an axial hole extending along an axis of the insulator, the insulator holding the center electrode within the axial hole at the front end thereof; and
a metallic shell accommodating the intermediate trunk portion of the insulator and having a crimp portion at the rear end thereof,
wherein the intermediate trunk portion of the insulator includes:
a shoulder portion pressed forward by means of the crimp portion,
a maximum diameter portion disposed frontward of the shoulder portion and having a maximum outer diameter among those portions constituting the intermediate trunk portion, and
an intermediate diameter portion connecting the shoulder portion and the maximum diameter portion, having a smaller diameter than the maximum diameter portion by equal to or greater than 0.1 mm but not greater than 0.3 mm, and having an axial length of equal to or greater than 2.0 mm.