Abstract: A method and apparatus for determining color registration in a multi-color printing press having a plurality of printing stations. A process black registration mark is formed in an identified area by positioning a plurality of color registration marks on top of each other. The process black registration mark is position in a portion of the image that is intended to be printed black, and preferably adjacent to a black ink image. The identified area is examined to determine whether the process black registration mark is properly positioned.

Abstract: A motor control method is disclosed in which a drive motor is connected to an adjustable frequency power supply in which the frequency of the power supplied to the motor can be selectively varied. While the motor is running at a constant speed as determined by the frequency of the power supplied to the motor, the value of the current being supplied to the motor by the power supply is sensed and an actual current signal representative of said actual current value is produced. A reference current signal which is representative of a selected maximum current value and thereby a maximum load at which the motor speed may be increased is also provided. The actual current signal is compared with the reference current signal and if the former is less than or equal to the latter, an output signal is provided. In response to the output signal resulting from the comparison, the value of the actual frequency of the power supplied to the motor is increased to a preselected value so that the motor speed also increases.

Abstract: An overhead travelling crane for a structure subject to oscillations resulting from earthquake shocks, comprises a bridge having flanged main wheels at opposite ends which are supported on a circular runway rail attached to the structure. Restraint means are provided between each end of the crane bridge and the structure to damp or control horizontal shifting of the crane relative to the structure resulting from horizontal oscillations of the structure to thereby prevent damage to the flanged main wheels and runway rail and crane derailment. The restraint means comprise a pair of shock absorber assemblies, one mounted at each end of the crane bridge, which are in constant resilient engagement with the sides of the structure and prevent a gap or space from occurring which would allow for excessive accelerated movement of the crane bridge.