Cam-flange

A flange and closure therefor comprising:

• a flange body having an opening therethrough defined by an inner smaller diameter portion and a concentric outer larger diameter portion, the juncture of which provides an internal circumferential ledge, and including an internal circumferential groove in said opening larger diameter portion;
• a cylindrical closure plate having an inner end and an outer end and an external cylindrical surface, the cylindrical surface being defined by a larger diameter portion adjacent the plate outer end and a smaller diameter portion adjacent the plate inner end, the juncture of the cylindrical portions providing an external peripheral ledge, the diameters of the closure plate being slightly less than the corresponding diameters of said flange body whereby said closure plate may be removably positioned in said flange body with the ledges thereof in abutment;
• a plurality of cam plates each hingeably affixed to said closure plate outer end, each cam plate having an outer semi-circular peripheral edge portion configured as a segment of a circle of diameter substantially equal the diameter of said flange internal groove, such edge portions being of a thickness less than the length of said groove and each cam plate having an integral inner portion defining an inner edge which is non-concentric with respect to said outer semi-circular peripheral edge, the inner edge providing a cam surface for hingeably displacing the cam plate inwardly and outwardly;
• and
• a cam plate actuator pivotally and coaxially affixed to said closure plate having an arm portion engaging each said cam plate's inner edge to hingeably retract said cam plates when said actuator is rotated in one direction whereby the portions having said circular edges are within the diameter of said closure plate larger diameter portion, and to hingeably extend said cam plates when said actuator is rotated in the other direction whereby the semi-circular edges thereof extend within said flange groove to retain said closure plate in position within said flange body opening.