Control device for a printing machine

An apparatus for controlling an operating speed comprising:

• a printing press having multiple operating states;
• a motor for driving the printing press;
• a tachometer for sensing the operating speed of the motor;
• a braking mechanism for stopping the motor;
• and a control system, the control system comprising:
• an input means comprising at least one sensor which is independent of operator input for inputting signals indicating the operating state of the printing press;
• a drive circuit coupled to the sensor and the motor for selectively supplying a predetermined level of current to the motor, the predetermined level of current being determined by the operating state of the printing machine, the drive circuit including a quick stopping terminal for reducing the current supplied to the motor at a first rate and a normal stopping terminal for reducing the current supplied to the motor at a second rate, the first rate being faster than the second rate;
• a selectively activated circuit breaking means for stopping current flow to the drive circuit;
• and a monitoring device coupled to the sensor, the drive means, the selectively activated circuit breaking means, the tachometer and the braking mechanism, the monitoring device responsive to the signals from the sensor for determining a maximum permitted speed therefrom independent of operator input, the monitoring device including a look-up table containing the operating states of the printing press, where each of the operating states is associated with a value for the maximum permitted speed, the monitoring device comparing the speed of the motor indicated by the tachometer to the maximum permitted speed and triggering the quick stopping terminal to stop current flow to the motor if the maximum permitted speed is exceeded, the monitoring device activating the braking mechanism and the selectively activated circuit breaking means if the tachometer indicates the speed of the motor is not decreasing after the quick stopping terminal has been triggered.

An apparatus for controlling an operating speed comprising:

• a printing press having multiple operating states;
• a motor for driving the printing press;
• a tachometer for sensing the operating speed of the motor;
• a braking mechanism for stopping the motor;
• and a control system, the control system comprising:
• at least one sensor which is independent of operator input for providing input signals indicating an operating state of the printing press;
• a controller electrically connected to the sensor for receiving input signals from the sensor and for generating control signals corresponding thereto;
• a driver associated with the motor and connected to the controller for supplying electrical current to the motor at levels corresponding to the operating state of the printing press;
• a monitoring device responsive to the input signals from the sensor for determining a maximum permitted speed independent of operator input, the monitoring device continuously sensing the input signals, the monitoring device including a look-up table containing the operating states of the printing press, where each of the operating states is associated with a value for the maximum permitted speed;
• and the monitoring device being connected to the tachometer and to the driver for stopping the current supplied to the motor when the speed of the motor exceeds the maximum permitted speed.