US Patent 10124495 Retractable utility knife

A utility knife configured with a retractable cutting blade that is extended and retracted by a blade actuation mechanism. The blade actuation mechanism includes a slider button assembly and a blade carriage assembly that are operably connected in variety of configurations, including a configuration with a rack-and-pinion arrangement between the slider button assembly and the blade carriage assembly. The rack-and-pinion blade actuation mechanism is configured to automatically retract the cutting blade as the cutting blade is lifted from the cutting surface.