Randomly and integrally re-keyable lock apparatus and method

In a re-keyable lock apparatus, including a lock cylinder housing with a cylindrical bore extending therethrough along a longitudinal axis;

• a plurality of longitudinally spaced, elongated top pinways in said housing extending perpendicular to and radially outward from said cylindrical bore;
• a cylindrical plug positioned rotatably in and defining a shear interface with said bore;
• said plug having a longitudinal keyway therein for receiving a key bit and a plurality of longitudinally spaced bottom pinways extending radially inward from the peripheral surface thereof into said keyway;
• opposite pairs of said bottom pinways and top pinways being adapted to align with each other to form a plurality of common pinways;
• a top driver pin and a bottom tumbler pin slidably positioned in each of said common pinways;
• said plug being rotatable when the interface between said top and bottom pins is aligned with said shear interface and not being rotatable when one said pin is positioned through said shear interface;
• the improvement comprising:
• master pin means adapted to be directly moved within said lock from one of said common pinways to a randomly selectable other one of said common pinways for providing an additional interface between said top and bottom pins therein to align with said shear interface;
• key means adapted for insertion into said keyway and being bitted on one side for positioning said master pin means above said shear interface in one of said top pinways and rendering said plug rotatable from a first position to a second unlocked position, said second unlocked position being less than 180.degree. from said first position;
• means formed in said peripheral surface of said cylindrical plug and located in alignment with said top pinways when said plug is in said second position for receiving said master pin means to enable said lock to be re-keyed when said plug is in said second position;
• blocking means mounted in said receiving means for normally preventing said master pin means from entering said receiving means, said blocking means being removable from said receiving means to permit said re-keying of said lock;
• and
• master pin transfer means adapted to be slidably received in said receiving means upon removal of said blocking means for receiving said master pin means from said top pinway of said first common pinway and carrying said master pin means within said lock apparatus directly into alignment with said top pinway of said randomly selectable other one of said common pinways.

A re-keying apparatus for randomly relocating a master pin between the top and bottom pins in a plurality of pinways of a tumbler pin lock that has a shear interface that is not penetrated by any of said pins to enable the lock to be operated, the master pin initially being between the top and bottom pins in a first of said pinways and being transferrable to a position between the top and bottom pins in a randomly selected other one of said pinways in the operation of said lock, the cylinder plug being rotatable less than 180.degree. from a first locked position to a second unlocked position, comprising:

• a first key bit adapted for insertion into a keyway of the lock and having bittings along one edge thereof adapted for aligning the interface between the master pin and the bottom pin in the first pinway with the shear interface so that said cylinder plug can be rotated to said second, unlocked position;
• a groove formed in the outer surface of the cylinder plug and aligned with the pinways upon rotation of said cylinder plug into said second unlocked position, said groove being dimensioned for receiving a master pin from the pinways and permitting the master pin to slide randomly from one pinway to another pinway;
• a blocking rod normally receieved in said groove for preventing said master pin from entering said groove in the normal use of the lock, said rod being removable from said groove to permit reception of the master pin in said groove for re-keying the lock;
• a master pin carrier adapted to be received in said groove after removal of said blocking rod for rotary and sliding movement relative to said groove, said master pin carrier having a cut formed in one side thereof for receiving the master pin and having a cam adjacent said cut;
• and
• handle means connected to said master pin carrier and adapted to extend through said groove and out of the lock for sliding said carrier in said groove to align the master pin in said cut with said randomly selected pinway and for rotating said carrier in said groove to cause said cam to remove the master pin from said cut and transfer the master pin into said randomly selected pinway.

A method of rendering a lock re-keyable with a plurality of different change keys, said re-keying being without disassembling said lock each time said lock is re-keyed for a different change key, wherein said lock is designed so that the re-keying can be performed only upon disassembly of said lock;

• said lock including a housing;
• a bore extending axially through said housing to define a shear interface;
• a plug received in said bore and having a keyway that extends therein from a first surface thereof;
• said housing and said plug having aligned holes therein forming at least first and second pinways that are located at opposite axial ends of said plug and that are divided by said shear interface;
• said plug being rotatably received in said bore for rotation less that 180.degree. from a first locked position to a second unlocked position;
• a first pin stack including a first tumbler pin and a first driver pin received in said first pinway, and a second pin stack in said second pinway and including a second driver pin and a second tumbler pin, said method of rendering said lock re-keyable comprising the steps of:
• removing said plug from said bore;
• inserting at least one master pin in said first pinway between said first tumbler pin and said first driver pin;
• forming a groove in the outer surface of said plug to be aligned with said pinways when said plug is at said second unlocked position, said groove being formed for a distance corresponding to the distance from said first pinway to said second pinway, the depth of said groove being sufficient to receive said master pin and the width of said groove being sufficient to permit said master pin to slide from a first forward end to a second rearward end of said groove;
• forming an extension of said groove to the front of said plug, said extension being dimensioned to prevent said master pin from moving forwardly past said front end;
• inserting a rod into said extension and said groove for normally preventing said master pin from being received in said groove;
• and
• replacing said plug in said bore.

A method of re-keying a lock for use with a plurality of different change keys and a single master key without disassembling the lock or removing any parts therefrom, said lock including a housing;

• a bore extending through said housing to define a shear interface;
• a plug received in said bore and having a keyway that extends therein from a first surface thereof, said housing and said plug having aligned holes therein forming at least first and second pinways that are spaced in the direction in which said bore extends through said housing and that are divided by said shear interface;
• a groove formed in said first surface of said plug at least for a distance corresponding to the distance from said first pinway to said second pinway, the depth and width of said groove being sufficient to receive said master pin, said groove being formed in said plug at a location spaced from said keyway by between about 45.degree. and 135.degree., said groove being normally blocked by a removable rod;
• said plug being received in said bore for rotation of less than 180.degree.;
• a first pin stack including a first tumbler pin, at least one master pin and a first driver pin received in said first pinway, and a second pin stack in said second pinway and including a second driver pin and a second tumbler pin;
• said method comprising the steps of:
• inserting into said keyway a key having bittings for unlocking said lock and positioning said master pin above said shear interface;
• removing said blocking rod from said groove;
• inserting into said groove a master pin transfer tool, said tool having a cut therein and a cam opposite to said cut;
• rotating said plug to an unlocked position with said tool in alignment with said pinways;
• moving said tool relative to said groove to position said cut for receiving said master pin from said first pinway;
• moving said tool relative to said groove to slide said master pin within said groove into alignment with said second pinway;
• moving said tool relative to said groove to transfer said master pin from said cut into said second pinway so that the heights of said pin stacks in said first and second pinways are changed by the height of said master pin so that said second change key must have a shallower bitting depth corresponding to said first pinway and can have a deeper bitting depth corresponding to said second pinway;
• rotating said plug to move said groove out of alignment with said pinways;
• removing said tool from said groove;
• replacing said rod in said groove;
• and
• removing said key from said keyway to enable use of said re-keyed lock with said second change key.