Magnetic stirring device

Claim 1

A SELF-ILLUMINATED MAGNETIC STIRRING DEVICE FOR SUPPORTING, AGITATING, AND ILLUMINATING THE CONTENTS OF A TRANSPARENT VESSEL CONTAINING A MAGNETIC STIRRING MAGNET, DURING TITRATIONS AND LIKE OPERATIONS, SAID DEVICE COMPRISING: AN ENCLOSED BASE HAVING AN ENLARGED OPENING IN THE TOP SURFACE THEREOF; A THIN, RIGID, TRANSLUCENT PLASTIC COVER PLATE, COVERING SAID OPENING IN THE TOP OF THE BASE, FOR SUPPORTING A VESSEL ON SAID BASE; A DRIVE MAGNET MOUNTED IMMEDIATELY BELOW SAID COVER PLATE FOR MAGNETIC COUPLING TO A STIRRING MAGNET IN SAID VESSEL, SAID DRIVE MAGNET BEING ROTATABLE ABOUT A VERTICAL AXIS; VARIABLE SPEED DRIVE MEANS, INCLUDING A MOTOR MOUNTED WITHIN SAID BASE, FOR ROTATING SAID DRIVE MAGNET TO EFFECT CORRESPONDING ROTATION OF SAID STIRRING MAGNET AND THEREBY AGITATE THE CONTENTS OF THE VESSEL; GOVERNOR MEANS FOR APPLYING AN INCREASINGLY GREATER DRAG TO SAID DRIVE MEANS WITH INCREASING SPEED OF ROTATION OF SAID DRIVE MAGNET TO MAINTAIN THE SPEED OF ROTATION THEREOF RELATIVELY CONSTANT UNDER VARYING LOAD CONDITIONS;