摘要 |
An improved hardened insert and brake shoe adapted for use in bi-directional backstopping clutches is disclosed. The inserts are formed from a base material of high speed alloy tool steel, which is relatively inexpensive and easy to machine. The base material is formed into the desired shape for the insert, then hardened and tempered by conventional processes to achieve a desired hardness. Then, a coating of titanium nitride is applied to the insert by a physical vapor deposition process or a chemical vapor deposition process. The titanium nitride coating provides a very hard surface to the insert, which permits the insert to be used in the backstopping clutch. In an alternative embodiment, the brake shoes are formed in the manner described above, and no inserts are used in the clutch. |