| 摘要 |
In an automatic screw thread cutting machine having a clamping carriage for clamping an elongated workpiece, one end portion of which is to be provided with a screw thread, and a spindle coaxially arranged with a workpiece held by said clamping carriage and carrying at one end thereof facing the end portion of the workpiece a screw cutting tool and being driven over a stepdown gearing from a motor, an advancing mechanism for advancing the clamping carriage towards said spindle and including a rod connected to the carriage and having a pair of opposite smooth parallel friction surfaces and a friction wheel driven by the spindle and pressed against one of the friction surfaces while the other friction surface is engaged by a counter roll. The friction wheel is exchangeble against a friction wheel of different diameter to thereby change the speed of advancement of the carriage. |
