Method and apparatus for duplicating keys using tip-referenced alignment between key blank and master key

A key cutting machine for simultaneously duplicating both the bit notch pattern and shoulder position of a master key onto a key blank, the key blank including a shank with an uncut length, a shoulder, a blade with an uncontoured surface and an original blade length, a tip and a first longitudinal axis, the master key including a shank with a surface and a length, a shoulder, a blade with a contoured surface forming a bit notch pattern and a blade length, a tip and a second longitudinal axis aligned relative to the master key as the first longitudinal axis is aligned relative to the key blank, the original key blank blade length being shorter than the master key blade length, comprising:

• a. a key blank alignment fixture for longitudinally aligning the key blank relative to a key cutter at a longitudinal index position spaced apart from the key tip by a first distance along the first longitudinal axis of the key blank and for laterally aligning the key blank relative to the key cutter to engage the key cutter with the shank or blade at the first distance to define a lateral reference distance relative to the first longitudinal axis;
• b. a master key alignment fixture for longitudinally aligning the master key relative to a key follower at the longitudinal index position spaced apart from the key tip by the first distance along the second longitudinal axis of the master key and for laterally aligning the master key relative to the key follower to engage the key follower with the shank or blade at the first location at a distance offset from the second longitudinal axis by the lateral reference distance;
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• c. a displacement mechanism for longitudinally and laterally displacing the key follower relative to the master key to trace the contour of the master key shank, shoulder and bit notch pattern while simultaneously displacing the key cutter relative to the key blank in an identical manner to reproduce the traced contour of the master key shank, shoulder and bit notch pattern on the key blank and to longitudinally reposition the key blank shoulder to coincide with the relative longitudinal location of the master key shoulder by cutting away a portion of the shank to reduce the length of the shank to thereby increase the blade length to a length greater than the original key blank blade length and equal to the master key blade length.

A key cutting machine for simultaneously duplicating both the bit notch pattern and shoulder position of a master key onto a key blank, the key blank including a shank with an uncut length, a shoulder, a blade with an uncontoured surface and an original blade length, a tip and a first longitudinal axis, the master key including a shank with a surface and a length, a shoulder, a blade with a contoured surface forming a bit notch pattern and a blade length, a tip and a second longitudinal axis aligned relative to the master key as the first longitudinal axis is aligned relative to the key blank, the original key blank blade length being shorter than the master key blade length, comprising:

• a. a base;
• b. a first cutter head for positioning a first key follower at a first elevation and for positioning a first key cutter at a second spaced apart elevation;
• c. a key blank alignment fixture for longitudinally aligning the key blank relative to the first key cutter at a longitudinal index position spaced apart from the key tip by a first distance along the first longitudinal axis of the key blank and for laterally aligning the key blank relative to the first key cutter to engage the first key cutter with the shank or blade at the first distance to define a lateral reference distance relative to the first longitudinal axis;
• d. a master key alignment fixture for longitudinally aligning the master key relative to the first key follower at the longitudinal index position spaced apart from the key tip by the first distance along the second longitudinal axis of the master key and for laterally aligning the master key relative to the first key follower to engage the first key follower with the shank or blade at the first location at a distance offset from the second longitudinal axis by the lateral reference distance;
• e. a first linear displacement mechanism coupled to the base and to the first cutter head for laterally displacing the first key follower toward and away from the master key and for simultaneously and equally laterally displacing the first key cutter toward and away from the key blank;
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• f. a second linear displacement mechanism coupled to the base, to the key blank alignment fixture and to the master key alignment fixture for longitudinally displacing the master key relative to the key follower to trace the contour of the master key shank, shoulder and bit notch pattern while simultaneously displacing the key blank relative to the key cutter in an identical manner to reproduce the traced contour of the master key shank, shoulder and bit notch pattern on the key blank and to longitudinally reposition the key blank shoulder to coincide with the relative longitudinal location of the master key shoulder by cutting away a portion of the key blank shank to reduce the length of the shank to thereby increase the blade length to a length greater than the original key blank blade length and equal to the master key blade length.

A key cutting machine for simultaneously duplicating both the bit notch pattern and shoulder position of a master key onto a key blank, the key blank including first and second shanks each with an uncut length and a surface, first and second shoulders, a blade with uncontoured first and second opposing surfaces each with an original surface length, a tip and a first longitudinal axis, the master key including first and second shanks each with a surface and a length, first and second shoulders, a blade with contoured first and second opposing surfaces forming a first bit notch pattern with a length and a second bit notch pattern with a length, a tip and a second longitudinal axis aligned relative to the master key as the first longitudinal axis is aligned relative to the key blank, the original surface lengths of the key blank blade being shorter than the length of the master key bit notch patterns, comprising:

• a. a key blank alignment fixture for longitudinally aligning the key blank relative to a first and a second key cutter at a longitudinal index position spaced apart from the key tip by a first distance along the first longitudinal axis of the key blank and for laterally aligning the key blank relative to the first and second key cutters to engage the first and second key cutters with the shank or blade at the first distance to define a lateral reference distance relative to the first longitudinal axis;
• b. a master key alignment fixture for longitudinally aligning the master key relative to a first and second key follower at the longitudinal index position spaced apart from the key tip by the first distance along the second longitudinal axis of the master key and for laterally aligning the master key relative to the first and second key followers to engage the key followers with the shank or blade surfaces at the first location at a distance offset from the second longitudinal axis by the lateral reference distance;
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• c. a displacement mechanism for longitudinally and laterally displacing the first and second key followers relative to the master key to trace the contour of the master key shanks, shoulders and bit notch patterns while simultaneously displacing the first and second key cutters relative to the key blank in an identical manner to reproduce the traced contours of the master key shanks, shoulders and bit notch patterns on the key blank and to longitudinally reposition the key blank shoulders to coincide with the relative longitudinal location of the master key shoulders by cutting away a portion of each shank to reduce the length of each shank to thereby increase each key blank blade length to a length greater than each original key blank blade length and equal to each corresponding master key blade length.