Lock cylinder and key combination

A key and lock cylinder combination comprising:

• a key including a bow and a blade extending from and connected to the bow, the blade defining a longitudinal axis along the length of the blade and defined by a first lateral side and a second lateral side opposite the first lateral side, the blade having pin engaging portions at a top of the blade, a first pin surface extending in the direction of the longitudinal axis on the first lateral side, and a second pin surface extending in the direction of the longitudinal axis on the first lateral side, the first pin surface and the second pin surface oriented to face in opposite directions, and each of the first pin surface and the second pin surface having an increase in elevation at respective ends of the first and second pin surfaces adjacent the bow when the longitudinal axis is horizontal;
• a housing including a wall defining a hollow portion, and a pin portion defining an outer pin chamber;
• an outer pin disposed in the outer pin chamber;
• a plug including a body rotatably housed within the hollow portion of the housing, the housing and the plug cooperating to define a shear line, the plug defining a key slot extending at least partially through the body in a longitudinal direction of the plug, the plug further defining an inner pin chamber disposed within the body and in communication with the key slot and selectively aligned with the outer pin chamber, and an auxiliary pin chamber in communication with the key slot and offset from the key slot;
• an inner pin disposed in the inner pin chamber and extending into the key slot such that the inner pin is engageable by the pin engaging portions;
• and
• an auxiliary pin disposed in the auxiliary pin chamber and in communication with the key slot and engaged by the first pin surface upon insertion of the key into the key slot to move the auxiliary pin to a withdrawn position to allow rotation of the plug relative to the housing, the auxiliary pin also engaged by the second pin surface upon removal of the key from the key slot to move the auxiliary pin to a projecting position in which the auxiliary pin projects from the plug and is engageable with the housing to prevent rotation of the plug relative to the housing.

A lock cylinder comprising:

• a housing including a wall defining a hollow portion, and a pin portion defining at least two outer pin chambers;
• outer pins disposed in each of the outer pin chambers;
• a plug including a body rotatably housed within the hollow portion of the housing, the housing and the plug cooperating to define a shear line, the plug defining a key slot extending at least partially through the body in a longitudinal direction of the plug, the plug further defining at least two inner pin chambers disposed within the body and in communication with the key slot and selectively aligned with the outer pin chambers, and an auxiliary pin chamber in communication with the key slot;
• inner pins disposed in each of the inner pin chambers and extending partially into the key slot such that the inner pins are engageable by a key;
• and
• an auxiliary pin disposed in the auxiliary pin chamber and in communication with the key slot, the auxiliary pin including a substantially cylindrical upper portion and a lower planar portion, the auxiliary pin further including a first projection defining a first engagement surface engageable by a key to move the auxiliary pin to a withdrawn position to allow rotation of the plug relative to the housing, and a second projection spaced apart from the first projection and defining a second engagement surface generally facing the first engagement surface and engageable by the key to move the auxiliary pin to a projecting position in which the auxiliary pin projects from the plug and is engageable with the housing to prevent rotation of the plug relative to the housing.

A key for a lock cylinder, the key comprising:

• a bow;
• and
• a blade extending from and connected to the bow, the blade defining a longitudinal axis along the length of the blade and defined by a first lateral side and a second lateral side opposite the first lateral side, the blade having pin engaging portions at a top of the blade, a first pin groove extending in the direction of the longitudinal axis on the first lateral side and defining a first pin surface, and a second pin groove extending in the direction of the longitudinal axis on the first lateral side and defining a second pin surface, the first pin surface oriented to face the top of the blade and the second pin surface oriented to face a bottom of the blade such that the first pin surface and the second pin surface face in opposite directions, and each of the first pin surface and the second pin surface engageable with a pin of the lock cylinder to move the pin between a withdrawn position and a projecting position,
• wherein each of the first pin surface and the second pin surface has an increase in elevation toward the bow when the longitudinal axis is horizontal such that the pin is movable upward upon insertion of the key into the lock cylinder, and the pin is movable downward upon removal of the key from the lock cylinder.