US Patent 8020543 Crossbow dry fire arrestor

Disclosed in a dry fire arrestor for a crossbow having a trigger mechanism operable to fire an arrow or bolt, that includes a spring plate, trigger sear connected to the trigger mechanism, an anti-dry fire bar for engaging and disengaging the trigger sear. The dry fire arrestor utilizes tension provided by the spring plate to allows anti dry fire bar to automatically engage the trigger sear, precluding movement of the trigger when an arrow in not properly inserted in the dry fire arrestor.