Abstract: A parallel redundant fan system includes at least first and second fans located adjacent each other. Each fan includes: (i) a fan housing defining a fan chamber in which an impeller is supported for rotation about an axis of rotation; (ii) a first chamber outlet in communication with the fan chamber and defined by an opening in a first wall of the fan housing; (iii) a second chamber outlet in communication with the fan chamber and defined by an opening in a second wall of the fan housing; and, (iii) first and second backflow prevention dampers respectively associated with the first and second chamber outlets. The first and second dampers respectively include first and second damper plates that selectively pivot from their closed positions toward their opened positions against the closing force of respective first and second counterweights in response to exhaust air flow pressure exerted thereon.

Abstract: A parallel redundant fan system includes at least first and second fans located adjacent each other. Each fan includes: (i) a fan housing defining a fan chamber in which an impeller is supported for rotation about an axis of rotation; (ii) a first chamber outlet in communication with the fan chamber and defined by an opening in a first wall of the fan housing; (iii) a second chamber outlet in communication with the fan chamber and defined by an opening in a second wall of the fan housing; and, (iii) first and second backflow prevention dampers respectively associated with the first and second chamber outlets. The first and second dampers respectively include first and second damper plates that selectively pivot from their closed positions toward their opened positions against the closing force of respective first and second counterweights in response to exhaust air flow pressure exerted thereon.

Abstract: A parallel redundant fan system includes at least first and second fans located adjacent each other. Each fan includes: (i) a fan housing defining a fan chamber in which an impeller is supported for rotation about an axis of rotation; (ii) a first chamber outlet in communication with the fan chamber and defined by an opening in a first wall of the fan housing; (iii) a second chamber outlet in communication with the fan chamber and defined by an opening in a second wall of the fan housing; and, (iii) first and second backflow prevention dampers respectively associated with the first and second chamber outlets. The first and second dampers respectively include first and second damper plates that selectively pivot from their closed positions toward their opened positions against the closing force of respective first and second counterweights in response to exhaust air flow pressure exerted thereon.

Abstract: A parallel redundant fan system includes at least first and second fans located adjacent each other. Each fan includes: (i) a fan housing defining a fan chamber in which an impeller is supported for rotation about an axis of rotation; (ii) a first chamber outlet in communication with the fan chamber and defined by an opening in a first wall of the fan housing; (iii) a second chamber outlet in communication with the fan chamber and defined by an opening in a second wall of the fan housing; and, (iii) first and second backflow prevention dampers respectively associated with the first and second chamber outlets. The first and second dampers respectively include first and second damper plates that selectively pivot from their closed positions toward their opened positions against the closing force of respective first and second counterweights in response to exhaust air flow pressure exerted thereon.

Abstract: A disc saw felling head has the cutting pocket positioned relative to the tooth entry opening into the housing such that chips being thrown out of the kerf by the teeth are thrown radially outwardly of the entry opening. The chips are thrown against a deflector plate which redirects them back toward the center but away from the disc to dissipate energy in the chips, reduce the directions in which chips are thrown, and reduce clogging of the housing.

Abstract: A disc saw felling head has the cutting pocket positioned relative to the tooth entry opening into the housing such that chips being thrown out of the kerf by the teeth are thrown radially outwardly of the entry opening. The chips are thrown against a deflector plate which redirects them back toward the center but away from the disc to dissipate energy in the chips, reduce the directions in which chips are thrown, and reduce clogging of the housing.