Apparatus and method for detaching portions of glass rods

• US 20080006669A1
• Filed: 03/16/2007
• Published: 01/10/2008
• Est. Priority Date: 03/16/2006
• Status: Active Grant

• Current Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Original Assignee: Schott AG (Carl-Zeiss-Stiftung)
• Inventors: Stangl, Albert, Kopp, Michael, Piegendorfer, Johann, Zöttl, Martin
• Granted Patent: US 8,439,241 B2
• Time in Patent Office: Days
• US Class Current: 225/002
• CPC Class Codes: C03B 33/06 Cutting or splitting glass tubes, rods, or hollow products C03B33/09 takes precedence
• CPC Class Codes: C03B 33/10 Glass-cutting tools, e.g. scoring tools
• CPC Class Codes: Y10T 225/12 With preliminary weakening
• CPC Class Codes: Y10T 225/307 Combined with preliminary weakener or with nonbreaking cutter
• CPC Class Codes: Y10T 225/325 With means to apply moment of force to weakened work

Abstract

The invention is based on the object of improving the detachment of portions of a glass rod to the extent that a very planar, uniform fracture surface is produced. For this purpose, an apparatus according to the invention for detaching portions of glass rods comprises a device for the parallel holding and lateral fixing of a number of glass rods, a scoring wheel holder with a scoring wheel rotatably mounted parallel to the axis of the glass rods, at least one pressing spring for pressing the scoring wheel and the glass rods against one another, a device for guiding the glass rods and the scoring wheel past one another in a direction perpendicular to the axis of the glass rods, a holddown means for pressing against the glass rods, a breaking bar and a breaking beam, the breaking bar being arranged opposite, between the holddown means and the breaking beam.

Claims

1. An apparatus for detaching portions (30) of glass rods (3), comprising:

a device for the parallel holding and lateral fixing of a number of glass rods (3);

a scoring wheel holder with a scoring wheel (5) rotatably mounted parallel to the axis of the glass rods (3);

at least one pressing spring for pressing the scoring wheel (5) and the glass rods (3) against one another;

a device for guiding the glass rods (3) and the scoring wheel (5) past one another in a direction perpendicular to the axis of the glass rods (3);

a holddown means (15) for pressing against the glass rods (3);

a breaking bar (11); and

a breaking beam (13), the breaking bar (11) being arranged opposite, between the holddown means (15) and the breaking beam (13).

2. The apparatus as claimed in claim 1, in which the breaking bar (11) is arranged opposite the scoring wheel (5), which is guided between the holddown means (15) and the breaking beam (13).

3. The apparatus as claimed in claim 1, wherein the scoring wheel (5) is rotatably mounted without any play in the axial direction.

4. The apparatus as claimed in claim 1, wherein the glass rods (3) are mounted in a rotationally fixed manner during the scoring by the device for parallel holding and lateral fixing.

5. The apparatus as claimed in claim 1, wherein the breaking bar (11) and the breaking beam (13) extend in a direction perpendicular to the axis of the glass rods (3).

6. The apparatus as claimed in claim 1, wherein the scoring wheel holder comprises a rotatably mounted lever, on which the scoring wheel (5) is held.

7. The apparatus as claimed in claim 6, wherein the pressing spring acts on a lever arm of the lever.

8. The apparatus as claimed in claim 1, wherein the scoring wheel holder is laterally guided in a bearing block by means of corresponding guiding surfaces.

9. The apparatus as claimed in claim 1, wherein the scoring wheel holder comprises a carriage which is guided transversely in relation to the direction of advancement and the axes of the glass rods, to which the scoring wheel is fastened and on which the pressing spring acts.

10. The apparatus as claimed in claim 1, which comprises one of i) a hydraulic damping element and ii) a pneumatic damping element for damping the movement of the scoring wheel.

11. The apparatus as claimed in claim 1, which further comprises a pneumatic pressing spring.

12. The apparatus as claimed in claim 11, which further comprises a dynamic gas flow spring.

13. The apparatus as claimed in claim 1, wherein one of the holddown means (15) and the breaking beam (13) has elastic holding elements for the glass rods (3), for the exertion of spring forces in the direction of the pressing direction of the scoring wheel (5).

14. The apparatus as claimed in claim 1, which comprises a scoring wheel with a scoring edge that leaves behind a scoring zone with a width of at least 20 micrometers, with preference at least 40 micrometers, on the lateral surface of the glass rod.

15. A method for detaching portions of glass rods (3), the method comprising:

holding a number of glass rods (3) in a parallel and laterally fixed manner;

guiding the glass rods (3) and a scoring wheel (5) rotatably mounted parallel to the axis of the glass rods (3) past one another in a direction perpendicular to the axis of the glass rods (3); and

pressing the scoring wheel (5) and the glass rods (3) against one another by means of at least one pressing spring, the glass rods (3) being bent between a holddown means (15) and a breaking beam (13) by means of a breaking bar arranged opposite, between the breaking beam (13) and the holddown means (15), and consequently portions of the glass rod (3) being detached at the scoring location.

16. The method as claimed in claim 15, the breaking bar (11) being arranged opposite the scoring wheel (5), which is guided between the holddown means (15) and the breaking beam (13), and acting as an abutment for the pressure exerted on the glass rods (3) by the scoring wheel (5).

17. The method as claimed in claim 15, wherein the scoring wheel (5) is rotatably mounted without any play in the axial direction.

18. The method as claimed in claim 15, wherein the scoring is introduced by the scoring wheel (5) only into part of the circumference of the glass rod.

19. The method as claimed in claim 15, wherein the glass rods (3) are mounted in a rotationally fixed manner during the scoring.

20. The method as claimed in claim 15, wherein portions of solid glass rods are detached.

21. The method as claimed in claim 15, wherein tubes of relatively long glass rods (3) are detached.

22. The method as claimed in claim 15, wherein the scoring wheel (5) is held by a rotatably mounted lever (71).

23. The method as claimed in claim 22, wherein the pressing spring (9) acts on a lever arm (73) of the lever (71).

24. The method as claimed in claim 15, wherein the scoring wheel holder (7) is laterally guided in a bearing block (8) by means of corresponding guiding surfaces (74, 75, 84, 85).

25. The method as claimed in claim 15, wherein the scoring wheel is held on a carriage which is guided transversely in relation to the axes of the glass rods and the direction of advancement and, when the glass rods and scoring wheel are guided past one another and the scoring wheel rolls on the glass rods, the carriage is moved in the guide by the glass rods against the spring force of the pressing spring.

26. The method as claimed in claim 15, wherein the movement of the scoring wheel is one of i) hydraulically damped and ii) pneumatically damped.

27. The method as claimed in claim 15, wherein the scoring wheel is pressed against the glass rods by a pneumatic pressing spring.

28. The method as claimed in claim 27, wherein the scoring wheel is pressed against the glass rods by a dynamic gas flow spring.

29. The method as claimed in claim 15, wherein the glass rods (3) are pressed onto the opposite breaking bar (11) by spring forces exerted by one of the holddown means (15) and the breaking beam (13) during the scoring.

30. The method as claimed in claim 15, wherein pressure is exerted on a glass rod by the scoring wheel for a time period of 0.05 of a second to 0.5 of a second.

31. The method as claimed in claim 15, wherein a scoring zone with a width of at least 10 micrometers, with preference at least 30 micrometers, is introduced on the lateral surface of the glass rod by the scoring wheel.

32. A glass rod portion produced in accordance with the method of claim 15, wherein the ends of the glass rod portions are fracture surfaces, and the length tolerance of the portions is less than ±

0.08 of a millimeter.

33. The glass rod portion as claimed in claim 32, wherein the fracture surfaces have an angularity perpendicular to the lateral surface of less than ±

0.08 of a millimeter per millimeter of outside diameter.

34. The glass rod portion as claimed in claim 32, wherein the fracture surfaces have a planarity of better than 0.06 of a millimeter per millimeter of outside diameter.

35. An optical waveguide, comprising a glass rod portion as claimed in claim 32.