Lock with normally non-removable key and auxiliary key removal device for use in interior locksets

In a key for a pin-type tumbler lock, the key being of the type having a series of spaced-apart pin notches therein positioning a series of lock pin sets permitting rotation of a lock cylinder when the key is properly inserted axially inwardly into a lock cylinder slot;

• the improvements comprising:
• an abutment axially inwardly adjacent at least one of said pin notches having obstructing surface means thereon at all times axially obstructing that lock pin upon that lock pin being received in said one pin notch for preventing radial disengagement of that lock pin from said one pin notch upon an attempted usual axial removal of said key from said lock cylinder key slot;
• all pin notches including said one pin notch having usual surface means at axial sides thereof axially outward of said lock cylinder where necessary for at all times permitting free usual insertion of said key into said key slot in usual manner, all pin notches except those having said obstructing surface means thereon having usual surface means at axial sides thereof axially inward of said lock cylinder where necessary for at all times permitting free usual removal of said key from said key slot;
• a separate key removal member positionable adjacent said key having removal surface means thereon for initially moving that lock pin radially along said key abutment during and while permitting axial inward insertion of said key removal member into said adjacent positioning relative to said key and then retaining that lock pin both radially and axially clear of said abutment, thereby permitting usual removal of said key from said lock cylinder key slot.

In a keyed, pin-tumbler lock of the general type having a lock cylinder rotatable in a lock casing, a key slot in the cylinder, a series of radial pin holes partially in each of the lock casing and cylinder and intersecting the key slot, resiliently inwardly urged sets of casing and cylinder pins with one set in each pin hole, a key in the key slot axially intersecting each of the pin holes with a key notch therein for each set of pins positioning that pin set with a parting line between its casing and cylinder pins at a casing-cylinder parting line permitting cylinder rotation by the key;

• the improvements in combination therewith comprising:
• a radial pin hole at least in said lock cylinder intersecting said key slot;
• a cylinder pin in said cylinder pin hole;
• resiliently reacting means for urging said cylinder pin into said key slot, said resiliently reacting means including resilient means in said pin hole at all times solely within said lock cylinder for urging said cylinder pin into said key slot;
• a key notch in said key radially aligned with and abutting an end of said cylinder pin when said key is properly in said key slot;
• abutment means on said key at an axial side of said key notch axially inward of said lock cylinder at all times axially obstructing said cylinder pin when said cylinder pin is in said key notch and in all positions of said lock cylinder for preventing radial disengagement of said cylinder pin radially from said key notch upon attempted removal of said key from said key slot to thereby prevent such key removal from said key slot in all positions of said lock cylinder;
• said resilient means being constructed and arranged relative to said cylinder pin to permit free rotation of said lock cylinder at all times at least when said cylinder pin is received in said key notch;
• a separate key removal member axially insertable into said key slot adjacent said key and having surface means thereon for moving and retaining said cylinder pin radially from said key notch and said abutment means obstruction to thereby permit axial removal of said key from said key slot.