Patent ID: 8267442

Claim:
An outer operational device for a panic exit door lock, comprising, in combination: a cover adapted to be mounted to a side of a door, with the cover defining a space; a handle including a shank having an engaging portion with non-circular cross sections, with the shank rotatably received in the cover; a latch movable between an extended, locking position and a retracted, unlocking position along a latch axis; an actuating member mounted in the space and including a first end and a connecting hole rotatably engaged on the shank, with the actuating member further including a first groove in an inner periphery of the non-circular connecting hole; a follower including a non-circular hole engaged with the engaging portion of the handle, with the follower and the handle rotating jointly, with a first tooth protruding out of the follower and engaged in the first groove, with the first tooth having a thickness in a vertical direction perpendicular to the latch axis smaller than a thickness of the follower in the vertical direction, with the handle, the actuating member, and the follower rotating jointly about a first rotating axis spaced from the latch axis in the vertical direction, with the first tooth breakable by an excessive force applied to the handle; a first link including an upper end and a lower end, with the lower end of the first link pivotably coupled with the first end of the actuating member; and a driving member including a pivotal portion pivotably received in the space of the cover, with a first wing extending from the pivotal portion and pivotably coupled at a first pivot axis to the upper end of the first link, with the first pivot axis being positionally fixed relative to each of the first wing and the first link, with a driving rod securely coupled with the pivotal portion, with the driving rod and the driving member rotating jointly about a second rotating axis parallel to and spaced from the first rotating axis, with the second rotating axis located between the first rotating axis and the latch axis, with a spacing between the second rotating axis and the latch axis being larger than a spacing between the second rotating axis and the first rotating axis, with the driving rod operably coupled to the latch, wherein rotation of the handle causes rotation of the follower and the actuating member about the first rotating axis to move the first link to push the first wing, causing rotational movement of the driving member, and the driving rod rotates jointly with the driving member about the second rotating axis, moving the latch between the extended, locking position and the retracted, unlocking position along the latch axis, wherein if the handle is rotated by the excessive force, the first tooth is broken and the handle rotates freely without rotating the actuating member, the first link and the driving member.