VORRICHTUNG ZUR HERSTELLUNG EINES STROEMUNGSMITTELDICHTEN VERSCHLUSSES EINER OEFFNUNG

摘要

This invention relates to apparatus for forming a fluid tight closure of an opening in a vessel. The apparatus includes a conduit or fitting adapted to be connected to the vessel, a plug insertable into the conduit and a means for locking the plug in the conduit to prevent the plug from moving out of the conduit. The locking means includes a locking element engageable with the plug to lock it in place. A connector located in a lateral bore through the conduit is connected at one end of the locking element and its other end has a threaded engagement with a nut also located in the lateral bore. Stops are provided at opposite ends of the nut so that upon rotation of the nut to move the connector and locking element between retracted and locking positions, the nut will alternately engage the stops. By making the distance between the stops greater than the length of the nut, the nut is free to move longitudinally between the stops and this construction avoids maintaining close manufacturing tolerances with respect to the distance between the stops. In a preferred embodiment, the inner stop is provided by a shoulder between an outer larger diameter portion of the bore and an inner smaller diameter portion. A seal is carried by the connector to seal between it and the smaller diameter portion of the bore as the connector is reciprocated by turning the nut. Normally the locking element will engage the conduit when in fully retracted position to limit makeup of the nut on the connector and hence limit the outward travel of the connector so as to maintain the seal within the smaller diameter portion of the bore. However, if excessive torque is applied to the nut so as to break the engagement of the connector with the locking element, means are provided to limit further makeup of the nut on the connector and the seal is located so as to remain within the smaller diameter portion of the bore when the nut has a maximum makeup on the connector and both have been displaced outwardly so the nut is in engagement with the outer stop. With this construction, the connector does not rotate thereby enabling it to have a simple bifurcated connection with the locking element and to carry a seal which merely slides along the bore in the conduit without rotation. The seal also isolates the threaded connection from fluids within the vessel.