In 1921, Walter Schlage abandoned his previously patented Throw-Lock idea in favor of a push button design. The push-button design was Schlage's ninth application for a patent in the door-lock classification. This design, known as the Schlage Button Lock, incorporated push button locking with the cylindrical housing; the basic design of the Schlage cylindrical push-button lockset we know today.
In 1922, the first Schlage board of directors approved the design and began to tool up for what became the predecessor of the"A" lock. The first installation of Schlage locks were at the Berkeley home of Thomas Castberg, Walter Schlage's patent attorney.
On May 9, 1923, a patent was filed for a key activated rotatable tumbler lock. All previous Schlage locks were non-key operated. This was the first design of the"A" key and lock mechanism. This rocking tumbler design required a double sided key with at least one notch of a specific depth cut into each side. Patent 1,653,511 was granted in December 20, 1927. This key activated rotatable lock design was used until the filing of Patent 1,691,529 in January 1927, when Schlage introduced the seven tumbler wafer lock.
For the purpose of locking, previous locks used the push button design. This lock introduced the possibility of using only a Schlage Lock on an exterior door. The key blank was part number 920A, a center bowed blade with a modified diamond head shape.
On August 20, 1923, Walter Schlage applied for a patent which would become the recognizable"A" lock.
By the end of 1923, the original push button lock dies are completed. Assembly line construction of the"A" lock begins at the new factory at 49 Shotwell St., San Francisco.
The keyed F Series locks have a five-pin tumbler “C” keyway lock cylinder.
The S200 Series Interconnected Locks are designed to provide the security of a one inch throw deadbolt having the convenience of a lever handle cylindrical lock.