#$%^&*AU2008200384B220130131.pdf#####SURGICAL INSTRUMENT WITH REPLACEABLE LOADING UNIT ABSTRACT 5 A surgical stapling device (10) has an elongated body (14) and a removable loading unit (16) and a securing structure for securing the loading unit (16) onto the elongated body (14). Guiding ramps (302) guide the movement of the loading unit (16) as it is mounted onto the elongated body (14). A movable yoke (400) secures the loading unit (16) onto the elongated body (14). A sensor mechanism (510) is engaged by the loading unit (16) 10 and moves with the securing structure. The locking structure (513) has a first position for blocking movement of the sensor mechanism (510) and preventing removal of the loading unit (16). The locking structure (513) has a second position for allowing the loading unit (16) to be removed from the device (10).1/22 CIII