Cutting head for a milling machine for manufacturing ophthalmic lenses made of plastic
A milling head for a milling machine for producing synthetic spectacle lenses, comprising a rotational axis, a coupling part for tensioning into a milling spindle chuck, a shoulder which connects to the coupling part with a contact surface for the milling spindle chuck, a shaft which is connected to the shoulder and a blade collar with an outer diameter D which is connected to the shaft and which comprises several cutting plates with a radius R, wherein between the blade collar at the height of the outer diameter D and the contact surface, a free length L is provided. The measurement of the free length L in relation to the measurement of the outer diameter D and the measurement of the radius R fulfills the following condition: lLl=0.18 (lDl−2lRl)+54±a, with a maximum deviation a of 3.
1. A milling head for a milling machine for producing synthetic spectacle lenses, comprising a rotational axis, a coupling part for tensioning in a milling spindle chuck, a shoulder which is connected to the coupling part with a contact surface for the milling spindle chuck, a shaft which is connected to the shoulder and a blade collar with an outer diameter D which is connected to the shaft and which comprises several cutting plates with a radius R, wherein between the blade collar at the height of the outer diameter D and the contact surface, a free length L is provided,
wherein the measurement of the free length L in relation to the measurement of the outer diameter D and the measurement of the radius R fulfills the following condition:
lLl= 0.18( lDl− 2 lRl )+54± a,
with a maximum deviation a of 3; and wherein the shaft over a length I which corresponds at least 50% to the length L. comprises a diameter d between 10 mm and 32 mm.
2. The milling head according to claim 1 , wherein the length l is between 80% and 120% of the outer diameter D.
3. The milling head according to claim 1 , that wherein the blade collar comprises twelve cutting plates over its circumference U.
4. The milling head according to claim 1 , wherein the shaft over a length l which corresponds at least 50% to the length L, comprises a diameter d of maximum 16 mm.
5. The milling head according to claim 1 , wherein the shaft over a length l which corresponds at least 50% to the length L, comprises a diameter d with 26 mm.
6. The milling head according to claim 4 , wherein the length l is between 80% and 120% or the length l is 100% of the outer diameter D.
7. The milling head according to claim 5 , wherein the length l is between 80% and 120% or the length l is 100% of the outer diameter D.
8. The milling head according to claim 2 , wherein the blade collar comprises twelve cutting plates over its circumference U.
9. The milling head according to claim 4 , wherein the blade collar comprises twelve cutting plates over its circumference U.
10. The milling head according to claim 5 , wherein the blade collar comprises twelve cutting plates over its circumference U.
11. The milling head according to claim 6 , wherein the blade collar comprises twelve cutting plates over its circumference U.
12. The milling head according to claim 7 , wherein the blade collar comprises twelve cutting plates over its circumference U.
13. The milling head according to claim 4 , wherein the length l is 100% of the outer diameter D.
14. The milling head according to claim 5 , wherein the length l is 100% of the outer diameter D.
15. A milling head for a milling machine for producing synthetic spectacle lenses, comprising a rotational axis, a coupling part for tensioning in a milling spindle chuck, a shoulder which is connected to the coupling part with a contact surface for the milling spindle chuck, a shaft which is connected to the shoulder and a blade collar with an outer diameter D which is connected to the shaft and which comprises several cutting plates with a radius R, wherein between the blade collar at the height of the outer diameter D and the contact surface, a free length L is provided,
wherein the measurement of the free length L in relation to the measurement of the outer diameter D and the measurement of the radius R fulfills the following condition:
ILI= 0.18( IDI− 2 IRI )+54± a,
with a maximum deviation a of 3; and
wherein the milling head is operable with a rotational speed of approximately 25,000 rpm.
16. The milling head according to claim 15 , wherein the shaft over a length I which corresponds at least 50% to the length L, comprises a diameter d between 10 mm and 32 mm.
17. The milling head according to claim 16 , whrein the length I is between 80% and 120% of the outer diameter D.
18. The milling head according to 15 , wherein the blade collar comprises twelve cutting plates over its circumference U.
19. The milling head according to claim 15 , wherein the shaft over a length I which corresponds at least 50% to the length L, comprises a diameter d of maximum 16 mm.
20. The milling head according to claim 15 , wherein the shaft over a length I which corresponds at least 50% to the length I, comprises a diameter d with 26 mm.