Adjustable roof ventilator

Abstract

An adjustable roof ventilator has a base, a ventilation assembly and an interlocking arrangement for securing the ventilation assembly to the base at a desired tilt angle. The base has a bottom peripheral flange mountable on a pitched roof, and an elbow member upwardly projecting from the flange. The ventilation assembly has an upper venting arrangement in communication with a lower duct portion having front, rear and side walls defining a cross-sectional configuration tiltably mountable on the elbow member. The side walls have lower rounded front edges and the front wall has a lower edge extending between upper ends of the rounded edges so that the rounded edges are in pivotal engagement against the flange of the base as the rear wall of the duct portion is in sliding engagement against a curving rear wall of the elbow member when the duct portion is tiltably mounted on the elbow member.

1 . An adjustable roof ventilator mountable on a pitched roof, comprising:
 a base having a bottom peripheral flange mountable on the pitched roof, and an elbow member upwardly projecting from the bottom peripheral flange, the elbow member having a front wall, a forwardly curving rear wall extending opposite the front wall of the elbow member, and opposite side walls extending between the front and rear walls of the elbow member;   a ventilation assembly having an upper venting arrangement, and a lower duct portion in communication with the venting arrangement, the lower duct portion having opposite front and rear walls and opposite side walls defining a cross-sectional configuration tiltably mountable on the elbow member of the base, the side walls of the lower duct portion having lower rounded front edges and the front wall of the lower duct portion having a lower edge extending between upper ends of the rounded edges so that the rounded edges are in pivotal engagement against the peripheral flange of the base as the rear wall of the lower duct portion is in sliding engagement against the rear wall of the elbow member when the lower duct portion is tiltably mounted on the elbow member; and   an interlocking arrangement for securing the ventilation assembly to the base at a desired tilt angle.   
     
     
         2 . The adjustable roof ventilator according to  claim 1 , wherein the upper venting arrangement comprises a grating portion extending above the lower duct portion and defining vent openings. 
     
     
         3 . The adjustable roof ventilator according to  claim 2 , wherein the upper venting arrangement further comprises peripheral outwardly declining fins mountable on the grating portion in registration with the vent openings for defining airflow passages in communication with the vent openings. 
     
     
         4 . The adjustable roof ventilator according to  claim 2 , wherein the upper venting arrangement further comprises a cap mountable on an upper end of the grating portion. 
     
     
         5 . The adjustable roof ventilator according to  claim 2 , wherein the grating portion and the lower duct portion are adjoining portions of a same sheet of material folded and having opposite ends attached together to form an open ended boxlike structure. 
     
     
         6 . The adjustable roof ventilator according to  claim 5 , wherein the vent openings are made of rows of holes through the sheet of material. 
     
     
         7 . The adjustable roof ventilator according to  claim 1 , wherein the front wall of the elbow member has a flat shape upwardly and forwardly slanting with respect to a plane defined by the bottom peripheral flange so that the lower edge of the front wall of the lower duct portion extends next to the front wall of the elbow member when the lower duct portion is tiltably mounted on the elbow member. 
     
     
         8 . The adjustable roof ventilator according to  claim 7 , wherein the front wall of the elbow member has a forwardly slanting angle with respect to the plane defined by the bottom peripheral flange corresponding to a minimum tilting angle of the ventilation assembly on the base. 
     
     
         9 . The adjustable roof ventilator according to  claim 7 , wherein a distance between lower edges of the front and rear walls of the elbow member defines a curvature radius of the rear wall of the elbow member with respect to the lower edge of the front wall of the elbow member, the distance between the lower edges of the front and rear walls of the elbow member being greater than a distance between upper edges of the front and rear walls of the elbow member. 
     
     
         10 . The adjustable roof ventilator according to  claim 1 , wherein the ventilation assembly has an adjustable tilting range relative to the base corresponding to vertical/horizontal roof pitch ratios of 2/12 to 18/12. 
     
     
         11 . The adjustable roof ventilator according to  claim 1 , wherein the front wall of the elbow member has a height exceeding a height whereat the lower edge of the front wall of the lower duct portion extends relative to lower edges of the side and rear walls of the lower duct portion. 
     
     
         12 . The adjustable roof ventilator according to  claim 1 , wherein the interlocking arrangement comprises screws engageable with the lower duct portion and the elbow member. 
     
     
         13 . The adjustable roof ventilator according to  claim 1 , wherein the forwardly curving rear wall of the elbow member has a lower flat portion and an upper curving portion. 
     
     
         14 . The adjustable roof ventilator according to  claim 13 , wherein the lower flat portion of the forwardly curving rear wall forwardly slants with respect to a plane defined by the bottom peripheral flange.