| 摘要 |
A pair of frame members are secured to the ends of a pair of adjacent generally circular ducts. Each frame member includes a vertical wall extending upwardly from the circular duct and a sloped outer wall angularly spaced from the vertical wall. Each frame member includes an annular pocket for receiving an end of the circular duct, and a base wall abutting the annular pocket. The base wall has a rebent end portion for engaging a plurality of protuberances positioned on the inside wall of the circular duct. The frame members have an expanding means to urge the frame end portions away from each other to increase the diameter of the frame and engage the duct end portion. A gasket is positioned between the vertical walls of adjacent frame members to contact the adjacent vertical walls, and a clamp is positioned in surrounding relationship with the pair of adjacent frame members secured to the pair of adjacent circular ducts. The clamp has a pair of legs, each leg contacting a frame member sloped outer wall. The clamp includes tightening means for reducing the diameter of the clamp. As the tightening means is operated to reduce the diameter of the clamp, the clamp legs are moved in a direction towards the adjacent circular ducts to slide along the adjacent frame members sloped outer walls. As the legs are moved along the adjacent sloped outer walls, the pair of adjacent frame members are urged towards each other and into further contact with the gasket to provide an air-tight connection between the circular ducts. |
