Cylinder lock-key-combination, a key therefor and a method of producing the key from a key blank

A key for a cylinder lock (1) which comprises a cylinder which is housed in a cylinder housing (2);

• a plug (3) which is accommodated in the cylinder housing (2) and has a key slot (3a), which defines a plane, and a row of pin tumblers (5) whose axes lie in one of the plane of the key slot and in a plane which is substantially parallel with the plane of the key slot, and in which the pin tumblers are operative to move in a pin tumbler plane and rotate about their axes when activated by the key (4);
• said key comprising side regions and a code which is formed in the side regions of the key and which functions to coact with the pin tumblers (5) in said row so that subsequent to inserting the key to its operative position in the key slot (3a), each pin tumbler will occupy a position which allows the plug (3) to be turned, wherein each tumbler (5) includes an engaging member in the form of a circular flange (5a);
• and wherein at least one side surface (4c) of the key (4) includes a receiving member in the form of a groove (4f) whose width varies along its length so as to accommodate the circular flanges (5a), and further wherein the groove (4f) has a number of defined, planar code position parts (4e) which extend parallel with the key insertion direction and which correspond to the number of tumblers (5) in the row in the plug (3);
• in that located between the planar code position parts (4e) are transition parts (4g) whose breadth is greater than the breadth of the code position parts, the breadths of which correspond to the height or thickness of the circular flanges (5a) and the breadth of which transition parts (4g) corresponds to the circular flanges (5a).

A method of producing a key from a key blank (4'), said key being for a cylinder lock (1) which comprises a cylinder which is housed in a cylinder housing (2);

• a plug (3) which is accommodated in the cylinder housing (2) and has a key slot (3a), which defines a plane, and a row of pin tumblers (5) whose axes lie in one of the plane of the key slot and in a plane which is substantially parallel with the plane of the key slot, and in which the pin tumblers are operative to move in a pin tumbler plane and rotate about their axes when activated by the key (4);
• said key comprising side regions and a code which is formed in the side regions of the key and which functions to coact with the pin tumblers (5) in said row so that subsequent to inserting the key to its operative position in the key slot (3a), each pin tumbler will occupy a position which allows the plug (3) to be turned, wherein each tumbler (5) includes an engaging member in the form of a circular flange (5a);
• and wherein at least one side surface (4c) of the key (4) includes a receiving member in the form of a groove (4f) whose width varies along its length so as to accommodate the circular flanges (5a), said method comprising the steps of:
• passing a cylindrical milling tool (10) having a diameter, thickness and configuration which correspond to the circular flanges (5a) along the key blank (4') in a plane which is parallel with the plane of the key blank and along a path which includes a plurality of straight parts (4e) and transition parts (4g) located therebetween;
• and
• cutting the groove (4f) in the key blank (4') such that a top side, bottom side and peripheral surface of the milling tool assist in said cutting, so that the groove (4f) has a greater width in the transition parts (4g) than in the straight parts (4e) to accommodate the circular flanges (5a) on the pin tumblers when the lock is used.