Flow dividing structure of mass flow controller
Patent 5099881 Issued on March 31, 1992. Estimated Expiration Date: 
February 22, 2011. 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.
February 22, 2011. 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.Patent References 1941467 2259592 3107689 3443417 Adjustable laminar flow bypass Non-degrading pressure regulator Patent #: 4886086 InventorAssigneeApplicationNo. 660552 filed on 02/22/1991US Classes:137/599.13, Including flowmeter73/202, Proportional137/601.18, Having guide or restrictor138/40, Restrictors251/118WITH MATERIAL GUIDE OR RESTRICTORExaminersPrimary: Hepperle, Stephen M.International ClassG01F 005/00Foreign Application Priority Data1990-08-31 JPAbstractA flow dividing structure for a mass flow controller includes a base having a main passage which includes an upsream circular passage, a downstream circular passage, and a tapering circular passage which connects the upstream and downstream circular passages. A plug inserted in the main passage includes a first cylindrical portion, a second cylindrical portion and a tapering frustoconical portion. A first annular passage is defined between the first cylindrical portion and the inner circumferential surface of the upstream circular passage. A second annular passage is defined between the second cylindrical portion and the inner circumferential surface of the downstream circular passage. A tapering annular passage is defined between the tapering frustoconical portion and the inner circumferential surface of the tapering circular passage. A flow measuring passage bypasses the tapering circular passage and connects the upstream circular passage with the downstream circular passage. | |
