Pivot arrangement for transferring pressurized air into a pivot door

Claim 1

In an entry structure including a door frame having spaced apart jambs and a header at the upper ends of the jambs, and a pivot device at the bottom of the door, the pivot device supporting the door and enabling the door to pivot about a vertical axis spaced slightly inwardly from one of the jambs, the improvement comprising: first means on the door at the upper end thereof defining a vertical bore which opens upwardly out of the door and having an opening therethrough, said opening communicating with said bore; a first fluid conduit connected with said opening in said first means so as to communicate with the bore, the first conduit leading to a fluid operated appliance on the door; second means on the header defining a vertical bore which is fixed in position with respect to the header and opens downwardly, the axis for the vertical bore of the second means being coincident with the axis of rotation for the door; a pin received in the bore of the second means and projecting downwardly therefrom into the bore of the first means so that the two bores are coaxial, the pin having a passageway extending axially through it with the lower end of the passageway opening into that portion of the bore in the first means which is located below the pin so that the passageway always communicates with the bore in the first means and the first fluid conduit irrespective of the angular position of the door; a second fluid conduit connected to the pin and communicating with the passageway therein seal means located between the pin and the walls of the bore in the first means to form a fluid barrier between the pin and the walls of that bore so as to prevent pressurized fluid from escaping along the pin, the seal means being positioned above said opening and also above the location at which the passageway in the pin opens into the bore of the first means, whereby the pressurized fluid will be transferred through the pin and into the second conduit without loss of pressure at the pin; and means for retracting the pin from the bore of the first means to free the upper end of the door from the header.