Abstract: A painters tool comprising at least one aperture matching a spindle of a window cranking mechanism which permits the tool to be used as a wrench to rotate the spindle of a window cranking mechansims.
Abstract: A sheet metal media free sound attenuator reduces noise from machinery and gas flow in duct systems, that has a solid outer shell box and at least one flow passage made of perforated sheet. The flow passage can have a gap called expansion chamber and supports that divide cavity between a wall of the perforated passage and a wall of the outer shell box. Entrance transition and exit transition of the sound attenuator provides smooth flow into the attenuator, reduces pressure drop, and increases attenuation. In the preferred embodiment, the perforated sheet is a perforated spiral sheet.
Type:
Grant
Filed:
November 21, 1997
Date of Patent:
September 4, 2001
Inventors:
William E. Thurman, Roger M. Coday, Prabhanjan Mysore