Multi-mode hammer drill with shift lock

A multi-mode hammer drill comprising:

• a support member having a lock surface and a shift surface;
• a shift member having a cooperating lock surface, the shift member being mounted on the support member in a configuration permitting movement of the shift member along the shift surface between a first mode position corresponding to a first mode of operation and a second mode position corresponding to a second mode of operation, and when the shift member is in the first mode position, the configuration permitting limited movement of the shift member between a lock position and an unlock position in a direction that is substantially perpendicular to the shift surface;
• a biasing member configured to exert a biasing force on the shift member toward the lock position where the lock surface can engage against the cooperating lock surface, when the shift member is in the first position;
• an actuation member coupled to the shift member in a configuration that, during shifting between the first mode of operation and the second mode of operation, exerts a force on the shift member that is sufficient to overcome the biasing force and cause movement of the shift member in a direction that is substantially perpendicular to the shift surface to an unlock position where the lock surface cannot engage against the cooperating lock surface, and thereafter, the actuation member moving the shift member from the first mode position to the second mode position.

A multi-mode hammer drill comprising:

• a support member having a lock surface, and a shift surface substantially perpendicular to the lock surface;
• a shift member having a cooperating lock surface, the shift member being mounted on the support member in a configuration permitting movement of the shift member along the shift surface between a first mode position corresponding to a first mode of operation and a second mode position corresponding to a second mode of operation, and when the shift member is in the first mode position, the configuration permitting limited rotational movement between a lock position and an unlock position;
• a biasing member configured to exert a biasing force on the shift member to cause rotation of the shift member toward the lock position where the lock surface can engage against the cooperating lock surface, when the shift member is in the first mode position;
• an actuation member coupled to the shift member in a configuration that, during shifting between the first mode of operation and the second mode of operation, exerts a force on the shift member in a direction that is substantially parallel to a direction of movement of the shift member and offset from the shift surface, the force exerting a moment on the shift member, thereby overcoming the biasing force and causing counter-rotation of the shift member into the unlock position where the lock surface cannot engage against the cooperating lock surface, and thereafter, the actuation member moving the shift member from the first mode position to the second mode position.