PAUL L DREYER
Engineers in Allentown, PA

4561472, Dec 31, 1985

Mar 20, 1984

6/591588

Paul L. Dreyer - Allentown PA
William R. McLennan - Easton PA

Ecolaire Incorporated - Malvern PA

F16K 336, F16K 4900

138 943

A conduit closure apparatus, e. g. , a damper, comprising a frame adapted for connection to a conduit in a position generally in registry with the conduit, a movable blade slidably mounted in the frame, means for moving the blade back and forth between an open position in which the blade is outside the conduit and a closed position in which the blade blocks the conduit, an opening in the frame through which the blade slides when it is moved between its open and closed positions, an inflatable sealing ring mounted in the frame that is operable, when inflated, to press against the face of the blade at the blade's periphery when the blade is in the closed position, thereby creating a seal between the blade and the frame, and means for inflating said sealing ring, is improved by including means for pulling a sufficient vacuum on the interior of the sealing ring to cause the ring to collapse and recede from contact with the blade, thereby creating a wider separation between the ring and the blade than if the interior of the ring were at atmospheric pressure. This lessens the chances of the sealing ring being abraded and damaged during movement of the blade, for example by encrustation on the side of the blade.

4474205, Oct 2, 1984

Mar 20, 1984

6/591587

Paul L. Dreyer - Allentown PA
William R. McLennan - Easton PA
Kenneth I. Conley - Northampton PA

Ecolaire Incorporated - Malvern PA

F16K 4300, F16K 320

137315

A conduit closure apparatus comprising a main frame adapted for connection to a conduit in a position generally in registry with the conduit, a movable blade slidably mounted in the frame, means for moving the blade back and forth between an open position in which the blade is outside the conduit and a closed position in which the blade blocks the conduit, a slot-like port through which the blade slides when it is moved between its open and closed positions, and an inflatable sealing ring that is operable, when inflated, to press against the face of the blade at the blade's periphery when the blade is in the closed position, thereby creating a seal between the blade and the frame, is improved by having the main frame define a channel which holds the edges of the blade when in the closed position, and having the inflatable ring being carried by a second frame, smaller than the main frame, which slidably fits in the channel of the main frane and which can be withdrawn from the main frame through the blade port for easy, relatively fast inspection, repair, or replacement of the inflatable ring, without disconnecting the main frame from the conduit and without need for entering the conduit.

4491144, Jan 1, 1985

Jul 8, 1983

6/512013

Paul L. Dreyer - Allentown PA
Russell F. Rarick - Orwigsburg PA

F16K 302, F16K 3312

137240

A sliding blade damper is provided with an improved seal arrangement around the blade withdrawal aperture. Two pairs of flexible sealing strips are used, mounted on either side of the aperture and pressing against the opposite sides of the blade. The unattached edges of the sealing strips are curled and bent away from the blade. The curled edges of one pair of strips hook the curled edges of the other pair, so that when the blade is inserted into the damper, the spreading apart of the first pair of strips serves to partially spread apart the second pair as well. In this manner the leading edge of the blade penetrates between the second pair of strips rather easily, lessening the chances that those strips will be bent or torn.