Flow rate detection mechanism with a restriction element for mass flow meters

Patent 6247495 Issued on June 19, 2001. Estimated Expiration Date:

December 1, 2019. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Flowmeter
Patent #: 5044199
Issued on: 09/03/1991
Inventor: Drexel, et al.

Flow dividing structure of mass flow controller Patent #: 5099881
Issued on: 03/31/1992
Inventor: Nakajima

Inventors

Application

No. 452636 filed on 12/01/1999

US Classes:

137/599.13, Including flowmeter73/202, Proportional73/861.58, Orifice and tapered plug137/487.5, Electrically actuated valve137/601.18, Having guide or restrictor138/46Variable restriction

Examiners

Primary: Rivell, John
Assistant: Krishnamurthy, Ramesh

Attorney, Agent or Firm

Price and Gess

International Classes

G01F 005/00
G01F 001/36

Foreign Application Priority Data

1998-12-07 JP

Abstract

A flow proportioning assembly for dividing a portion of a fluid flow such as gas for presentation to a sensor includes a holder member having a central opening and forming an exterior peripheral passageway when inserted within a conduit of a flow meter housing. A resistor member can be adjustably mounted in the central opening downstream of a holder member aperture to encourage a laminar flow pattern and a large entrance port and a large exit port can communicate with a passageway that is operatively connected with a sensor. The exit port is downstream of the resistor member. Flexible fastener members can engage the resistor member and the holder member for ease of mounting. The resistor member can also comprise a helical arrangement of small fluid passageways to encourage laminar flow.