Multiple-bolt locking mechanism for sliding doors

Abstract

A multiple-bolt locking mechanism particularly for use with sliding doors having a narrow stile frame movable into closed engagement with a tubular thin walled jamb frame structure and which comprises a vertically spaced upper main locking unit on the door narrow stile frame having a hook-type bolt actuatable by a key mechanism between an unbolted position and a dead-locked bolted position, a lower slave lock unit on the door narrow stile frame having a hook-type bolt, and a upper slave header locking unit, having a longitudinally reciprocable bolt for bolting engagement with door frame header keepers respectively at a door fully closed position and a door partially open position. The hook-type bolts are each movable into hooked bolted relation with a relatively thin wall portion of the jamb wall surrounding a bolt receiving opening therein and which is peripherally reinforced by being sandwiched between an associated inner backup steel plate member and an outer trim steel plate member. The header bolt is spring biased towards a fully projected normal position for operatively entering a receiving opening of a header keeper when the door is in fully closed position or in a partially open position, but is movable against the biasing spring to a retracted position upon failure of the bolt to enter the bolt receiving opening of an associated header keeper due to misalignment or upon engagement with an adjacent header surface.