In order to reduce the cost and increase the ability of competition, the machines used in the manufacturing process must be automated. In another word, fully automation is an important way to survive in this competitive world. Lathe is a widely used machine in the manufacturing process. Its operation already changed from traditional mechanical way to numerical control to achieve the automation. Now it is developed toward a high precision, high speed, and multi-functions machine. O ne important factor affecting the precision of manufacturing, the flexibility of work piece, and the ability of automation is the power chuck.

Due to the shape and/or the size of work pieces, the power chuck. often needs to be changed to some special designed fixture, or the work piece need to be switched to another type of machine to process. These will reduce the ability of automation of CNC lathes. Therefor, a new design is developed basing on the original pwer chuck by adding base-hole type fixture mechanism (Expansible sleeve type and C shaped press ring type) and press-plate type fixture mechanism to the original power chuck.

This new design can reduce the time of loading and unloading of the work pieces, enlarge the range of size of work pieces, and allow different shape of work pieces. These can improve the ability of automation of the CNC lathe. The new design will increase the clamping ability, eliminate the cost of making special fixture, and reduce the time of changing chuck and positioning the work pieces. All these will low down the cost of production and increase the ability of automation. Further more, a precise clamping mechanism can increase the precision of work pieces.