Self tapping duct fitting and method of use
OwnerRichard J. Goettelinventor
Life of this patent
Estimating the term…
Abstract
A duct fitting for connecting a branch duct to a main duct including a tubular body having cutting teeth formed on one end thereof for cutting a hole in the main duct by pressing the cutting teeth against the main duct and rotating the tubular body about its longitudinal axis. Subsequent to cutting of the hole, the cutting teeth are bent into engagement with the interior of the main duct to squeezingly hold the main duct between the bent over teeth and a resiliently deflectable mounting flange provided on the tubular body. An air diversion scoop is mounted in the bore of the tubular body and is pivotably moved so that a portion of the scoop extends from the tubular body into the main duct.
Claims16
A duct fitting for connecting a branch duct to a main duct comprising:
- (a) a tubular body defining a bore and having a first open end of circular cross section and defining a longitudinal axis;
- (b) cutting and mounting means on the first open end of said body for cutting a hole in the main duct when placed in abutting engagement therewith and said body is rotated about the longitudinal axis and for mounting the first open end of said body in the cut hole of the main duct, said cutting and mounting means including a plurality of alternately arranged teeth and separating slots formed axially and arranged radially on the first open end of said body;
- (c) a resiliently deflectable mounting flange circumscribingly mounted on the periphery of said body proximate the first open end thereof for biasingly engaging the exterior surface of the main duct upon mounting of said body thereon;
- (d) said tubular body being formed of a relatively thin gauge metal to provide each of said plurality of teeth with cutting edges and to allow said teeth to be bent over into engagement with the interior surface of the main duct upon mounting of said body thereon;
- and
- (e) air diversion scoop means mounted in the bore of said body for pivotable movement between a retracted position and an extended position wherein at least a portion of said air diversion scoop means extends beyond the first open end of said body.
A method for cutting a hole in the wall of a main duct and mounting a duct fitting therein comprising the steps of:
- (a) forming a cylindrical tubular duct fitting with an annular interrupted open end edge including an alternately arranged plurality of teeth and relatively narrower separating slots;
- (b) mounting a resiliently deflectable metal mounting flange about the periphery of said duct fitting adjacent the interrupted edge thereof;
- (c) mounting an air diversion scoop in the bore of said duct fitting for movement from a retracted to an extended position;
- (d) pressing the interrupted edge of said duct fitting against the main duct in which said duct fitting is to be mounted;
- (e) rotating said duct fitting about its longitudinal axis simultaneously with step d so that the interrupted edge thereof cuts a hole in the main duct;
- (f) removing said duct fitting from the cut hole of the main duct to extract the cut out piece therefrom;
- (g) pushing the cut out piece out of the bore of said duct fitting;
- (h) reinstalling the interrupted open edge of said duct fitting in the cut out hole in the main duct to move said resiliently deflectable mounting flange into bearing engagement with the main duct fitting;
- (i) pressing said duct fitting toward the main duct to axially deflect said mounting flange in a direction away from the main duct;
- (j) bending the teeth of the interrupted edge of the duct fitting into bearing engagement with the interior surface of the main duct simultaneously with step i;
- and
- (k) moving said air diversion scoop from its retracted position to its extended position wherein at least a portion thereof extends from said duct fitting into the main duct.
Dependencies are inferred from the claim text.