A multi-mode drill includes a housing, a motor and a transmission mechanism, wherein the motor and the transmission mechanism are received in the housing. The transmission mechanism has a gear reduction component and a main shaft, wherein the gear reduction component is driven by the motor, and the main shaft is connected with the gear reduction component and driven by the gear reduction component to rotate. The multi-mode drill further includes a mode switching mechanism for causing the transmission mechanism to operate in different modes. The mode switching mechanism includes an operation member and an actuator. The actuator is actuated by the operation member and engages with the transmission mechanism. At least an elastic energy storage member is arranged between the operation member and the actuator.

The restraining strap has a rectangular cross section with a broad side against cylindrical sections holding a release member. The moment of inertia for a rectangular cross section strap is represented by the formula I=BH3/12. The lower moment of inertia reduces the load on the fusible link. With no limit to the number of wraps around the cylindrical sections, higher preloads can be accommodated by increasing the number of wraps of the restraining strap without affecting the moment of inertia or the amount of force borne by the fusible link. The actuator has a catch extending between the restrainer and actuator. The catch ends engage the restrainer and actuator and, upon release from the actuator, the catch rotates to allow the restrainer to unwind from about the cylindrical sections.

A release device having a multi-segment split spool with a central bore adapted to axially restrain a tensioned member. A tensioned tape is overlappingly wound around the spool segments thereby preventing radial movement of the spool segments. The overlapping winding allows for a low profile housing for the-release device. The multiple segments require less radial motion for release of the tensioned member.

A mechanical actuator is disclosed. The mechanical actuator can comprise an interface portion configured to interface with an object, a spring configured to exert a force on the interface portion, and a shape memory member coupled to the interface portion. The shape memory member can be configured to fracture at a predetermined temperature range. Upon fracture of the shape memory member, the force of the spring can cause the interface portion to act on the object.