US Patent 8161780 Thumb operated door lock assembly

A thumb operated door latch and lock assembly has an exterior grip and thumb lever, a motion converter, a key cylinder, a strengthening plate and an interior latch lever and locking knob. The thumb lever moves the converter which turns a latch tongue that extends through a receiver in the latch assembly. The interior lever turns a limited engagement interior hub collar. A figure eight opening in the collar turns the latch tongue to withdraw the latches. Turning the interior lever upward disables the thumb lever. Turning the lever to withdraw the latches moves a slide upward within guide plates. The slide turns an interior lever and an extended tongue on the key cylinder to withdraw the dead bolt simultaneously with the latches.