The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 21, 2019
Filed:
Mar. 14, 2017
Rinnai Corporation, Nagoya-shi, Aichi, JP;
Tomoyuki Shimazu, Nagoya, JP;
RINNAI CORPORATION, Aichi, JP;
Abstract
A premixing apparatus in which a downstream end of a gas supply passage is connected to a gas suction section disposed in an air supply passage on an upstream side of a fan, is provided with: a butterfly valve driven by a stepping motor, for changing over, between high and low, a ventilation resistance in that section of the air supply passage which is on an upstream side of the gas suction section; a changeover valve for changing over, between high and low, a ventilation resistance in that section of the gas supply passage which is on an upstream side of a flow control valve; and an interlocking mechanism which opens or closes the changeover valve in interlocking with the rotation of the butterfly valve and which maintains the changeover valve in a closed state until the butterfly valve has rotated from the closed posture toward the opening side by a predetermined angle. Flame failure and poor combustion are prevented at the time of changing over the butterfly valve and the changeover valve from closed posture to opened posture. When the butterfly valve is rotated from the closed posture into the opened posture, a driving frequency of the stepping motor is made higher, until the butterfly valve has rotated from the closed posture toward the opening side by a predetermined set angle, than the driving frequency during the subsequent operation of the butterfly valve.