Spindle control system

A control system for a machine tool with a rotatable spindle comprising:

• (a) a pulse coder, coupled to the spindle, for producing pulse signals corresponding to rotational angular movement of the spindle and a pulse signal corresponding to a predetermined rotational position of the spindle;
• (b) means for converting the pulse signals corresponding to rotational angular movement of the spindle to a voltage proportional to the actual rotational speed of the spindle;
• (c) means for comparing the voltage proportional to the actual rotational speed of the spindle with a voltage representative of a commanded speed and controlling the actual rotational speed of the spindle to the commanded speed;
• and
• (d) a position controller having a register for setting a predetermined numerical value, having a means for converting the content of said register to a proportional voltage, and having a control circuit for regulating application of the voltage proportional to the commanded speed and the voltage proportional to the content of the register to the comparing and controlling means for governing movement of the spindle;
• wherein upon receipt of an instruction for stopping the spindle at the predetermined rotational position the predetermined numerical value is set with the position pulse signal and wherein the position controller provides the voltage proportional to the content of the register for stopping the spindle at the predetermined rotational position in place of the voltage representative of the commanded speed.

A control system for a machine tool with a rotatable spindle comprising:

• a pulse coder coupled to the spindle for producing pulse signals corresponding to rotational angular movement of the spindle and a pulse signal corresponding to a predetermined rotational position of the spindle;
• first means for converting the pulse signals corresponding to rotational angular movement of the spindle to a voltage proportional to the actual rotational speed of the spindle;
• a position control circuit, operatively connected to said pulse coder, having a register for setting a predetermined numerical value and having a means for providing a voltage proportional to the content of said register;
• second means for providing a voltage representative of a commanded speed;
• a third means, operatively connected to said first means, said second means and said position control circuit, for receiving the voltage proportional to the actual rotational speed of the spindle and for providing an output signal for controlling the actual rotational speed of the spindle;
• and
• a control circuit, operatively connected to said pulse coder, said position control circuit, said second means, and said third means, for regulating application of the voltage proportional to the commanded speed and the voltage proportional to the content of the register to the third means for governing movement of the spindle;
• wherein upon receipt of an instruction for stopping the spindle at the predetermined rotational position the predetermined numerical value is set with the position pulse signal and wherein said position control circuit provides the voltage proportional to the content of the register for stopping the spindle at the predetermined rotational position in place of the voltage representative of the commanded speed.