Level indicating device

An electrostatic copying apparatus which includes a device for indicating that the level of a dosable material has fallen below a predetermined level in a dosing container having a shaft mounted horizontally for rotation inside of the container and a dosing brush having a radius mounted on the shaft, said level indicating device comprising:

• an elastic contact tongue radially fixed to the shaft for rotation therewith, said contact tongue having an overall length which is greater than the radius of the brush, said contact tongue being sufficiently elastic so that it assumes a bent configuration under the drag of the dosable material, the bent configuration having a first radius when rotated in contact over a predetermined portion of its length with the dosable material, and so that it assumes an extended configuration having a second radius when rotated so that it is not in contact over said predetermined portion of its length with the dosable material;
• a contact pin mounted at a distance from the shaft greater than said first radius but not greater than said second radius, said second radius being sufficiently large with respect to said distance at which said contact pin is mounted so that said contact pin is contacted by said contact tongue in its extended configuration, said contact pin being mounted stationary on one of the walls of the container above the dosing brush;
• and
• means for producing a signal when said contact tongue contacts said contact pin.