Abstract: An apparatus is disclosed for removing exceeding portions of laths use to separate pieces of lumber in a bundle. The apparatus comprises an external cage and an internal cage having a skeleton framework mounted to the external cage and displaceable between a retracted position and an extended position in which the internal cage projects forwardly from a front open face of the external cage. A chain-like member carrying a plurality of paddles is provided at a front face of the skeleton framework and is driven by a motor for causing the paddles to strike and break the exceeding portions of the laths.