PURPOSE: To enable tools to be adjusted easily by providing a mechanism which displaces the position of the upper tool mounting frame of a tearing device by the combining of link mechanisms and an air cylinder.

CONSTITUTION: A pin 33 is pushed out leftward by the pushing out of a rod 31 with air blown into one side of an air cylinder C, and then an L-link 9 and a T-link 10 are operated to pull a tool mounting frame A upward. A space thereby is formed beneath the tool mounting frame A so that the transfer of paper sheets is unobstructed and so that the work of mounting or removing tools can be performed quickly. To punch the paper sheets with the tools mounted on the tool mounting frame A, air in one side of the cylinder C is vented and air is blown into the other side of the cylinder C to move the rod 31 rightward. The tool mounting frame A is thereby lowered, and at that position the tools are moved vertically by the rotation of a cam 39 so that the action of tearing the paper sheets is effected.