Bore serration for locking threaded inserts against rotation

• US 20080279652A1
• Filed: 05/08/2008
• Published: 11/13/2008
• Est. Priority Date: 05/08/2007
• Status: Active Grant

• Current Assignee: Rolls-Royce Deutschland Limited & Company KG (Rolls-Royce Holdings Plc)
• Original Assignee: Rolls-Royce Deutschland Limited & Company KG (Rolls-Royce Holdings Plc)
• Inventors: Mielke, Rainer
• Granted Patent: US 7,704,028 B2
• Time in Patent Office: Days
• US Class Current: 411/109
• CPC Class Codes: F16B 33/002 Means for preventing rotation of screw-threaded elements F16B39/00 takes precedence
• CPC Class Codes: F16B 37/122 Threaded inserts, e.g. "rampa bolts"
• CPC Class Codes: F16D 1/101 without axial retaining means rotating with the coupling
• CPC Class Codes: F16D 2001/103 the torque is transmitted via splined connections

Abstract

A bore serration for locking externally serrated inserts (3) against rotation, with the external serration (4) comprising several teeth (5), and particularly for use with components made of hard, brittle materials, includes an arcuate serration (10) featuring arcuate recesses (7) produced by plunge or circumferential surface milling. Each of the recesses positively accommodates at least two teeth (5) of the outer serration (4) of the threaded insert (3). The arcuate serration can be produced with high dimensional accuracy without damaging the workpiece and with reduced wear of the tool, and ensures a long service-life of the threaded insert.

Claims

1. A bore serration for locking externally serrated threaded inserts against rotation, the threaded insert having an external serration comprising a plurality of teeth, comprising an arcuate serration having a plurality of arcuate recesses produced by plunge or circumferential surface milling, and with each of the arcuate recesses receiving at least two teeth of the external serration of the threaded insert.

2. The bore serration of claim 1, wherein each arcuate recess receives up to four teeth of the external serration.

3. The bore serration of claim 2, wherein at least one arcuate recess is of a different size than the other arcuate recesses to receive a remainder quantity of the teeth if the number of teeth is not an integral multiple of the number of arcuate recesses.

4. The bore serration in of claim 3, wherein an arcuate surface of each arcuate recess engages at least a portion of outer flanks of the teeth positioned within the respective arcuate recess.

5. The bore serration of claim 4, wherein the arcuate recesses each include a radiused arcuate internal edge.

6. The bore serration of claim 1, wherein at least one arcuate recess is of a different size than the other arcuate recess to receive a remainder quantity of the teeth if the number of teeth is not an integral multiple of the number of arcuate recesses.

7. The bore serration in of claim 6, wherein an arcuate surface of the arcuate recesses engages at least a portion of outer flanks of the teeth positioned within the respective arcuate recess.

8. The bore serration of claim 7, wherein the arcuate recesses each include a radiused arcuate internal edge.

9. The bore serration in of claim 1, wherein an arcuate surface of the arcuate recesses engages at least a portion of outer flanks of the teeth positioned within the respective arcuate recess.

10. The bore serration of claim 1, wherein the arcuate recesses each include a radiused arcuate internal edge.

11. A method for creating a bore serration for locking externally serrated threaded inserts against rotation, comprising:

providing a threaded insert with an external serration having a plurality of teeth,

forming an arcuate serration in the bore, the arcuate serration having a plurality of arcuate recesses produced by at least one of plunge and circumferential surface milling, such that each of the arcuate recesses is constructed and arranged to receive at least two teeth of the external serration of the threaded insert.

12. The method of claim 11, wherein each arcuate recess is constructed and arranged to receive up to four teeth of the external serration.

13. The method of claim 12, wherein at least one arcuate recess is formed of a different size than the other arcuate recesses to receive a remainder quantity of the teeth if the number of teeth is not an integral multiple of the number of arcuate recesses.

14. The method of claim 13, wherein an arcuate surface of each arcuate recess is constructed and arranged to engage at least a portion of outer flanks of the teeth positioned within the respective arcuate recess.

15. The method of claim 14, wherein the arcuate recesses are each formed to include a radiused arcuate internal edge.

16. The method of claim 11, wherein at least one arcuate recess is formed of a different size than the other arcuate recesses to receive a remainder quantity of the teeth if the number of teeth is not an integral multiple of the number of arcuate recesses.

17. The method of claim 16, wherein an arcuate surface of each arcuate recess is constructed and arranged to engage at least a portion of outer flanks of the teeth positioned within the respective arcuate recess.

18. The method of claim 17, wherein the arcuate recesses are each formed to include a radiused arcuate internal edge.

19. The method of claim 11, wherein an arcuate surface of each arcuate recess is constructed and arranged to engage at least a portion of outer flanks of the teeth positioned within the respective arcuate recess.

20. The method of claim 11, wherein the arcuate recesses are each formed to include a radiused arcuate internal edge.