Allegion Schlage D Series, Manual

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8 • Schlage • Primus service manual
Construction and operating principles
Construction and operating principles
The Primus/Primus XP cylinder is a conventional Schlage
cylinder with a few modifications. A sidebar and finger pins are
added to the conventional cylinder to provide additional security.
The Primus/Primus XP key has a secondary bitting on the side of
the blade to accommodate the finger pins. When the key is
inserted, each of the side bit cuts lifts the finger pin and rotates it
so that the notches in the side bar align with the notches in the
back of the finger pins.
When all notches on the side bar and back of the finger pins are
aligned and the regular pins are aligned at the shear line the plug
is free to rotate.
D
O
N
O
T
D
U
P
L
IC
A
T
E
P
R
I
M
U
S
Finger Pin
Secondary side bitting
Finger pins rotated
Locked Unlocked
Finger Pin Springs
Finger Pins
Springs
Top Pins
Master Pins
(as needed)
Bottom Pins
Sidebar Springs
Sidebar