Oscillating level indicator

In a level-indicating apparatus for detecting the level of material within a container, having a drive motor, a motor drive shaft and a switch positioned adjacent the drive motor, the drive motor being energizable by means of the switch to provide continuous rotating motion to the motor drive shaft, said drive motor being movably mounted in a housing for swinging movement to actuate or deactuate said switch, a vane shaft extending out of said housing, and a vane coupled to said vane shaft and adapted to contact the material in said container to cause said swinging movement of said motor when a predetermined resistance is encountered by the vane, the improvement comprising:

• an auxiliary drive means interconnecting the motor drive shaft and the vane shaft to convert said continuous rotating motion of said motor drive shaft into rocking rotative movement, said rocking rotative movement being imparted to said vane shaft to cause movement of said vane in an oscillatory manner about the axis of the vane shaft;
• and
• flexible sealing means having first and second ends secured to said vane shaft and to said housing, respectively, so as to be sealed thereagainst and immovable in relation thereto, the flexible sealing means having a central portion capable of torsional flexing in response to the oscillatory movement of the vane shaft and vane.