US Patent 6926316 Portable security locks

A portable security lock for use with a hinged door includes a base plate that hooks into a keeper opening in a strike plate and a latch plate that is pivoted on the base plate and carries a locking foot which bears against the door when the door is closed. A sliding deadbolt is provided to lock the latch plate to the base plate after the locking foot is pivoted to engage the door. The sliding deadbolt is mounted on the latching plate and has a detent that projects through an opening in the base plate to keep the latching plate from rotating out of engagement with the base plate to thereby keep the latching plate locked to the base plate with the locking foot held against the door.