| 摘要 |
The machining spindle shaft assembly is for a machine having a tool contact detection system (11, Figure 1) for detecting when a tool carried by the spindle contacts a work piece (W, Figure 1). The shaft assembly 4 includes a hollow non-metallic shaft member 41 which houses a tool holder 5 for holding a machining tool (D, Figure 1), such as a drill bit. An electrically conductive coating (41a, Figure 4) is provided on an outer surface of the shaft member. An electrical conduction path is provided through the interior of the shaft member such that the tool holder is electrically connected to the conductive coating at a location towards an end of the shaft member which is remote from the tool holder. The shaft member may be a ceramic. The electrically conductive coating may be a metallic coating. At least some of the tool holder and shaft assembly parts may be bonded with an electrically conductive adhesive. |
