| 摘要 |
One part of a key-in-knob lock set functions in a normal manner such that when the lock set is unlocked, either the outside or inside knob can be manipulated to open the door by withdrawing the latch bolt from a normal spring latch extended position. When, instead, the lock set is locked, the latch bolt is extended an exceptionally long distance into the frame to a dead bolt position. Extension and retraction of the latch bolt to and from dead bolt position is accomplished by manipulation of a main cam through the agency of a key in the outside or a turn button on the inside. For withdrawing the latch bolt from the normal spring latch extended position, an escutcheon housing for the outside knob or a corresponding escutcheon housing for the inside knob serves, by moving transversely of the axis of rotation of the knob, to rotate a radially extending tooth-like element on the spindle which, acting through the main cam, withdraws the latch bolt. By rotation of the key on the outside, or the turn button on the inside, the spindle is rotated a greater amount, far enough to have the main cam extend the latch bolt an additional distance to the dead bolt position. In that dead bolt position the tooth-like element for the hub cam of the outside knob is moved out of the path of movement of the respective drive housing so that rotation of the outside knob has no effect on the latch bolt. The tooth-like element for the hub cam of the inside knob remains, however, in movable engagement with the corresponding drive housing so that rotation of the inside knob does in fact withdraw the latch bolt from the dead bolt position.
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