Abstract: A spark plug and method of construction thereof is provided. The spark plug includes a metal shell having a through cavity, a lower insulator and a plastic upper insulator. The lower insulator is received in the through cavity and has a through passage with a center electrode received therein. A ground electrode is operatively attached to the shell in spaced relation from the ground electrode to provide a spark gap. The plastic upper insulator has a distal end received in the through cavity of the shell and a terminal end extending axially outwardly from the shell. The upper insulator has a through passage extending between the terminal end and the distal end. An elongate conductive member is received in the through passage of the upper insulator and is configured for electrical communication with the center electrode.

Abstract: A spark plug and method of construction thereof is provided. The spark plug includes a metal shell having a through cavity, a lower insulator and a plastic upper insulator. The lower insulator is received in the through cavity and has a through passage with a center electrode received therein. A ground electrode is operatively attached to the shell in spaced relation from the ground electrode to provide a spark gap. The plastic upper insulator has a distal end received in the through cavity of the shell and a terminal end extending axially outwardly from the shell. The upper insulator has a through passage extending between the terminal end and the distal end. An elongate conductive member is received in the through passage of the upper insulator and is configured for electrical communication with the center electrode.

Abstract: A method is disclosed for modifying coordinate data in a machining program in response to workpiece measurements made by a programmably controlled surface sensing element. The location of the workpiece and position of workpiece characteristics are determined by a series of programmed scanning cycles. The maximum, minimum and average measured positions of points on a workpiece surface are stored and may be used to calculate position offsets which may be used to modify a machining program. Further, the measured positions and offsets may be tested against programmed maximum and minimum limits to determine if the measured positions are within a tolerance band. In one embodiment, the positions of points on the workpiece surface are measured by a cutting tool operating in conjunction with a torque measuring circuit.