Pneumatic control system for air handling system damper
US4887630A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 15, 1989 |
| Grant date | Dec 19, 1989 |
| Priority date | — |
| Expiry date | Mar 15, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/1963
- WIPO fieldThermal processes and apparatus
- WIPO sectorMechanical engineering
Abstract
A damper for an air handling system in which the blade or blades are normally positioned to permit air to flow through the damper by a pneumatic cylinder which, when pneumatically actuated, overcomes the force of a spring within the pneumatic cylinder which would otherwise position the blade or blades to close the damper to air flow. The pneumatic cylinder normally receives air through a primary outlet of a three-way valve, the three-way valve also having a vent outlet and a valve member which is movable to permit pneumatic flow either from a source of pneumatic fluid through the primary outlet or from the pneumatic cylinder back through the three-way valve for venting through the vent outlet. The valve member is biased to permit pneumatic flow only through the vent outlet, but it has a portion which extends beyond the valve body and which is restrained by a mechanism that includes a fusible link to restrain the movement of the valve member so that it normally only permits pneumatic flow through the primary outlet. In the event of a fire or other condition of excessive temperature the fusible link will fail, the valve member will move to its venting position, and the spring within …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.