Device for detecting viscosity of liquid

• US 4,677,845 A
• Filed: 12/05/1985
• Issued: 07/07/1987
• Est. Priority Date: 12/07/1984
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Naruse, Osamu, Horike, Masanori, Izumi, Kouji, Komai, Hiromichi, Furukawa, Tatsuya, Ebi, Yutaka
• Primary Examiner(s): Levy, Stewart J.
• Assistant Examiner(s): ROSKOS, JOSEPH
• Application Number:
  US06/804,612
• Time in Patent Office: 579 Days
• Field of Search: 73/56, 73/55, 137/92
• US Class Current: 73/54.11
• CPC Class Codes: G01N 11/04 through a restricted passage, e.g. tube, aperture
• CPC Class Codes: Y10T 137/2506 By viscosity or consistency

Abstract

A device for detecting viscosity of a liquid which varies with time includes a first tank provided with an overflow section for maintaining a predetermined liquid height, and a second tank fluidly communicated to the first tank and provided with a restricted outlet, or orifice. While a liquid is circulated through the two tanks by a pump, a height sensor which is dipped in the liquid in the second tank senses a liquid height in the tank in terms of capacitance. The output of the height sensor is representative of a viscosity of the liquid.

Claims

1. A device for detecting the viscosity of a liquid which circulated through a liquid supply system comprising:

a first tank for holding said liquid;

a supply means for supplying said liquid to said first tank;

a height regulator means coupled to said supply means for maintaining at a predetermined height said held liquid;

a second tank;

a conduit coupling said first and second tanks below the level of said held liquid for transferring said liquid from said first tank to said second tank;

an orifice in said second tank for providing an outflow of said liquid;

sensor means placed in said second tank and in direct contact with said liquid contained therein for sensing the height of said liquid in said second tank;

viscosity detecting means coupled to said sensor for calculating the viscosity of said liquid in response to the output of said sensor.

2. A device as claimed in claim 1, wherein said height regulator means comprises a triangular weir provided in an upper portion of the first tank.

3. A device as claimed in claim 1, said sensor means comprises a pair of conductors each being coated with plastic and dipped in the liquid inside the second tank.

4. A device as claimed in claim 1, wherein the liquid comprises ink which is circulated through an ink supply system of an ink jet printer.

5. A device as in claim 4 further comprising:

a third tank holding diluent;

a valve coupled to said viscosity detecting means for supplying said diluent held in said third tank to said ink supply.