US Patent 7559449 Energy stored in spring with controlled release

There is provided a surgical instrument including a handle having an elongated tubular member extending distally from the handle and one or more end effectors mounted on the distal end of the elongate tubular member. A driver is movably mounted within the handle and elongate tubular member in order to operate the end effectors. The surgical instrument includes an energy storage mechanism for storing and providing energy to move the driver and thereby actuate the surgical instrument. Various actuation mechanisms are disclosed which are operable on the energy storage mechanism to control the rate of release of the energy stored in the energy storage mechanism.