US Patent 9743929 Modular powered surgical instrument with detachable shaft assemblies

An interchangeable shaft assembly for a surgical instrument that includes first and second drive systems. The interchangeable shaft assembly is configured for removable attachment to a housing of the surgical instrument. Various embodiments include a latch system that enables the interchangeable shaft assembly to be detached from the housing when the first drive system is unactuated but prevents the interchangeable shaft assembly from being detached from the housing when the first drive system is in an actuated position.