Dead bolt system having multiple security features

Abstract

A dead bolt lock system which may use one or more security locks in conjunction with a dead bolt to provide various levels of security access to a door. Generally, the lock system tests the condition of the security lock or locks before allowing retraction of the dead bolt. An inside escape lever is provided as a life safety feature to allow egress from the secured area regardless of the conditions of the security locks. A trigger hold back device maintains the dead bolt in a retracted position until the door has been opened and closed again. Lock covers include associated locked-on-by-combination and relock features. A night latch or lock down feature is provided to prevent access, including authorized access through the outside of the lock system. A force blocking assembly is provided to prevent force applied to the dead bolt from harming internal components of the system. A torque override clutch prevents excessive torque applied to the outside door handle from harming internal lock system components.