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The invention is directed to a method for manufacturing a thin-wall, single-piece optical obturator having an integral tip and shaft. The invention includes providing an injection mold defining a mold cavity having a core pin positioned within the mold cavity. The mold includes at least one gate and

The invention is directed to a method for manufacturing a thin-wall, single-piece optical obturator having an integral tip and shaft. The invention includes providing an injection mold defining a mold cavity having a core pin positioned within the mold cavity. The mold includes at least one gate and multiple core support pins between the core pin and the mold cavity walls, with at least one primary core support pin positioned on a side opposite the at least one gate. The method also includes injecting a transparent molten polymeric material having high flow properties into the injection mold such that the polymeric material flows between the surface of the mold cavity and the core pin. The core support pins substantially prevent the core pin from shifting while the polymeric material is injected into the mold. The high-flow nature of the polymeric material allows for complete filling of the mold cavity.

대표청구항 ▼

The invention claimed is: 1. A method for manufacturing a thin-wall, single-piece optical obturator having a wall thickness less than 1.11 mm, the obturator including an integral tip and shaft, the shaft extending along an axis between a proximal end and a distal end with a lumen therebetween, the

The invention claimed is: 1. A method for manufacturing a thin-wall, single-piece optical obturator having a wall thickness less than 1.11 mm, the obturator including an integral tip and shaft, the shaft extending along an axis between a proximal end and a distal end with a lumen therebetween, the lumen being sized and configured to receive an optical instrument having a distal end for receiving an image of body tissue, comprising: providing an injection mold, the injection mold including, a mold cavity defining an outside surface of the single-piece optical obturator, a core pin positioned within the mold cavity, the core pin defining an inside surface of the single-piece optical obturator, the distance between an outer surface of the core pin and the surface of the mold cavity being 1.11 mm or less, at least one gate extending into the mold cavity, and at least one core support pin for supporting the core pin within the mold cavity, the at least one core support pin being positioned between a surface of the mold cavity and a surface of the core pin and on the side substantially opposite the at least one gate; and injecting a transparent, molten polymeric material having high flow properties into the injection mold such that the polymeric material flows between the surface of the mold cavity and the core pin. 2. The method of claim 1, further comprising sterilizing the optical obturator. 3. The method of claim 2, wherein the sterilizing step includes sterilizing with one of gamma radiation, electron beam sterilization and ethylene oxide sterilization. 4. The method of claim 1, wherein the injecting step includes injecting a high-flow polycarbonate material. 5. The method of claim 4, wherein the injecting step includes injecting a high-flow polycarbonate material that is capable of being sterilized by one of gamma radiation and electron beam sterilization. 6. The method of claim 5, wherein the injecting step includes injecting a high-flow polycarbonate material having a compensating colorant. 7. The method of claim 4, wherein the injecting step includes injecting a high-flow polycarbonate material that is capable of being sterilized by ethylene oxide sterilization. 8. The method of claim 4, wherein the injecting step includes injecting a high-flow polycarbonate material having a melt flow rate of about 20 grams/10 minutes or greater. 9. The method of claim 8, wherein the injecting step includes injecting a high-flow polycarbonate material having a melt flow rate between 20 grams/10 minutes and 60 grams/10 minutes. 10. The method of claim 4, wherein the injecting step includes injecting a high-flow polycarbonate material having a weight average molecular weight of about 24000 atomic mass units or lower. 11. The method of claim 4, wherein the injecting step includes injecting a high-flow polycarbonate material having a MOLDFLOW viscosity index of about 196 Pascal-seconds or less at a temperature of about 300° C. 12. The method of claim 11, wherein the injecting step includes injecting a high-flow polycarbonate material having a MOLDFLOW viscosity index of about 196 Pascal-seconds or less at a temperature between 282° C. and 316° C. 13. The method of claim 1, wherein the providing step includes providing an injection mold having at least two mold sections defining the mold cavity and the core pin being positioned substantially in the center of the mold cavity. 14. The method of claim 1, wherein the providing step includes providing an injection mold having two mold halves. 15. The method of claim 14, wherein the providing step includes providing an injection mold having two mold halves defining the mold cavity and the core pin being positioned in the mold cavity such that an axis of the core pin is positioned substantially coaxially with an axis of the mold cavity. 16. The method of claim 14, wherein the providing step includes providing an injection mold having two mold halves and a plurality of secondary core support pins included on each half of the mold cavity and distributed along the length of the mold cavity. 17. The method of claim 16, wherein the providing step includes providing an injection mold having secondary core support pins that interlock with the core pin. 18. The method of claim 16, wherein the providing step includes providing an injection mold having secondary core support pins that are adapted to pilot into the core pin. 19. The method of claim 18, wherein the providing step includes providing an injection mold having secondary core support pins that are adapted to pilot into the core pin to a depth of about 0.9 mm. 20. The method of claim 16, wherein the providing step includes providing an injection mold having longitudinal secondary core support pins that have a substantially circular cross-section along their lengths. 21. The method of claim 16, wherein the providing step includes providing an injection mold having four secondary core support pins on each mold half, the secondary core support pins being positioned substantially perpendicular to the core pin and substantially perpendicular to the at least one gate. 22. The method of claim 16, wherein the providing step includes providing an injection mold having five secondary core support pins on each mold half, the secondary core support pins being positioned substantially perpendicular to the core pin and substantially perpendicular to the at least one gate. 23. The method of claim 16, wherein the providing step includes providing an injection mold having secondary core support pins in the form of screws. 24. The method of claim 23, wherein the providing step includes providing an injection mold having the ends of the screws that are opposite the heads of the screws configured for piloting into the core pin. 25. The method of claim 16, wherein the providing step includes providing an injection mold having the secondary core support pins fixedly coupled to the mold halves. 26. The method of claim 16, wherein the providing step includes providing an injection mold having the secondary core support pins adjustably coupled to the mold halves. 27. The method of claim 16, wherein the providing step includes providing an injection mold having secondary core support pins positioned substantially perpendicular to the core pin and substantially parallel to the at least one gate on the same side of the mold as the at least one gate. 28. The method of claim 1, the providing step including providing an injection mold wherein the at least one core support pin includes at least one primary core support pin that is positioned substantially perpendicular to the core pin and substantially parallel to the at least one gate on the side of the mold opposite the at least one gate. 29. The method of claim 28, wherein the providing step includes the at least one primary core support pin including two primary core support pins distributed along the length of the mold cavity. 30. The method of claim 28, wherein the providing step includes the at least one primary core support pin including three primary core support pins distributed along the length of the mold cavity. 31. The method of claim 1, wherein the providing step includes providing an injection mold having a plurality of gates distributed along the length of the mold cavity. 32. The method of claim 31, wherein the providing step includes providing an injection mold having a series of three gates. 33. The method of claim 31, wherein the providing step includes providing an injection mold having a series of four gates. 34. A method for manufacturing a thin-wall, single-piece optical obturator having a wall thickness less than 1.11 mm, the obturator including an integral tip and shaft, the shaft extending along an axis between a proximal end and a distal end with a lumen therebetween, the lumen being sized and configured to receive an optical instrument having a distal end for receiving an image of body tissue, comprising: providing an injection mold, the injection mold including, two mold halves, a mold cavity having a longitudinal axis, the mold cavity defining an outside surface of the single-piece optical obturator, the mold cavity being defined by the two mold halves, a core pin having a longitudinal axis, the core pin defining an inside surface of the single-piece optical obturator, the core pin being positioned in the mold cavity such that the longitudinal axis of the core pin is positioned substantially coaxial with the longitudinal axis of the mold cavity, the distance between an outer surface of the core pin and the surface of the mold cavity being 1.11 mm or less, a plurality of gates extending into the mold cavity, the gates being distributed along the length of the mold cavity, at least one primary core support pin for supporting the core pin within the mold cavity between a surface of the mold cavity and a surface of the core pin, the at least one primary core support pin being positioned substantially perpendicular to the core pin and substantially parallel to the at least one gate on the side of the mold opposite the at least one gate, and a plurality of secondary core support pins included in each half of the mold cavity, the secondary core support pins supporting the core pin within the mold cavity between a surface of the mold cavity and a surface of the core pin, the secondary core support pins being distributed along the length of the mold cavity, each of the plurality of secondary core support pins being positioned substantially perpendicular to the core pin and substantially perpendicular to the at least one gate; and injecting a transparent, molten polycarbonate material having high flow properties into the injection mold such that the polycarbonate material flows between the surface of the mold cavity and the core pin. 35. The method of claim 34, wherein the injecting step includes injecting a material having a melt flow rate of about 20 grams/10 minutes or greater. 36. The method of claim 35, wherein the injecting step includes injecting a material having a melt flow rate between 20 grams/10 minutes and 60 grams/10 minutes. 37. The method of claim 34, wherein the injecting step includes injecting a material having a weight average molecular weight of about 24000 atomic mass units or lower. 38. The method of claim 34, wherein the injecting step includes injecting a material having a MOLDFLOW viscosity index of about 196 Pascal-seconds or less at a temperature of about 300° C. 39. The method of claim 38, wherein the injecting step includes injecting a material having a MOLDFLOW viscosity index of about 196 Pascal-seconds or less at a temperature between 282° C. and 316° C. 40. The method of claim 34, wherein the providing step includes providing an injection mold having secondary core support pins that interlock with the core pin. 41. The method of claim 34, wherein the providing step includes providing an injection mold having secondary core support pins that are adapted to pilot into the core pin. 42. The method of claim 41, wherein the providing step includes providing an injection mold having secondary core support pins that are adapted to pilot into the core pin to a depth of about 0.9 mm. 43. The method of claim 34, wherein the providing step includes providing an injection mold having secondary core support pins that have a substantially circular cross-section along their lengths. 44. The method of claim 34, wherein the providing step includes providing an injection mold having four secondary core support pins on each mold half. 45. The method of claim 34, wherein the providing step includes providing an injection mold having five secondary core support pins on each mold half. 46. The method of claim 34, wherein the providing step includes providing an injection mold having secondary core support pins in the form of screws. 47. The method of claim 46, wherein the providing step includes providing an injection mold having the ends of the screws that are opposite the heads of the screws configured for piloting into the core pin. 48. The method of claim 34, wherein the providing step includes providing an injection mold having the secondary core support pins fixedly coupled to the mold halves. 49. The method of claim 34, wherein the providing step includes providing an injection mold having the secondary core support pins adjustably coupled to the mold halves. 50. The method of claim 34, wherein the providing step includes the at least one primary core support pin including two primary core support pins distributed along the length of the mold cavity. 51. The method of claim 34, wherein the providing step includes the at least one primary core support pin including three primary core support pins distributed along the length of the mold cavity. 52. The method of claim 34, wherein the providing step includes providing an injection mold having a series of three gates distributed along the length of the mold cavity. 53. The method of claim 34, wherein the providing step includes providing an injection mold having a series of four gates distributed along the length of the mold cavity. 54. A method for manufacturing a thin-wall, single-piece optical obturator having a wall thickness less than 1.11 mm, the obturator including an integral tip and shaft, the shaft extending along an axis between a proximal end and a distal end with a lumen therebetween, the lumen being sized and configured to receive an optical instrument having a distal end for receiving an image of body tissue, comprising: providing an injection mold, the injection mold including, a mold cavity defining an outside surface of the single-piece optical obturator, a core pin positioned within the mold cavity, the core pin defining an inside surface of the single-piece optical obturator, the distance between an outer surface of the core pin and the surface of the mold cavity being 1.11 mm or less, and at least one core support pin for supporting the core pin within the mold cavity, the at least one core support pin being positioned between a surface of the mold cavity and a surface of the core pin; and injecting a transparent, molten polymeric material having high flow properties into the injection mold such that the polymeric material flows between the surface of the mold cavity and the core pin. 55. A method for manufacturing a thin-wall, single-piece optical obturator having a wall thickness less than 1.11 mm, the obturator including an integral tip and shaft, the shaft extending along an axis between a proximal end and a distal end with a lumen therebetween, the lumen being sized and configured to receive an optical instrument having a distal end for receiving an image of body tissue, comprising: providing an injection mold, the injection mold including, a mold cavity defining an outside surface of the single-piece optical obturator, a core pin positioned within the mold cavity, the core pin defining an inside surface of the single-piece optical obturator, the distance between an outer surface of the core pin and the surface of the mold cavity being 1.11 mm or less, at least one gate extending into the mold cavity, and at least one core support pin for supporting the core pin within the mold cavity, the at least one core support pin being positioned between a surface of the mold cavity and a surface of the core pin and on the side substantially opposite the at least one gate; and injecting a transparent, molten polymeric material into the injection mold such that the polymeric material flows between the surface of the mold cavity and the core pin.