PURPOSE: To permit the cam change in an exceedingly short time even in the operation of an automatic board by dividing a camshaft into minor shafts and applying a sleeve onto each minor shaft and installing the cam onto the sleeve, in the camshaft apparatus for a main-shaft transfer-type automatic board.

CONSTITUTION: A camshaft 83 is supported by beds 85 and 87 and divided into the first minor shaft 83a and the second minor shaft 83b, and connected together through an Oldham's coupling 93. A vertical cam group 97, head stock cam 99, chuck opening and closing cam 101 are set onto the minor shaft 83a. A shaft changing cam 103 for three-shaft attachment and a shaft pushing cam 105 are set onto the minor shaft 83b. These vertical cam group 97 and the cam 99 are fixed in demountable ways onto a sleeve 107 by a fixed ring 109, and fixed onto the minor shaft 83a by a nut 111. The indexing of this position is performed by using a curvic coupling 113. Also both cams 103 and 105 are installed onto a sleeve 117 on the minor shaft 83b.