US Patent 9488424 Charging handle with cog and spring

A firearm comprising an upper receiver and a charging handle is disclosed. A charging handle is coupled to the upper receiver and comprises a handle assembly rotationally coupled to a main body about a first and a second pivot point. The handle assembly includes a first handle having an edge nearest the main body and a latch extending from the first handle parallel to the main body for interfacing with the upper receiver in a first position, a second handle having an edge nearest the main body, and a plunger interfacing with the edge of the first handle and the edge of the second handle, and a spring, such that when force is applied to either handle, the plunger is pushed into the main body and energy is transferred to the handles, moving the latch into a second position.