Expanded – threaded – driven – headed – tool-deformed – or locked-thr – Headed fastener element with nut – washer – securing means or cap – Headed bolt or screw with threads and complementary nut
Reexamination Certificate
2000-03-06
2001-06-12
Wilson, Neill (Department: 3627)
Expanded, threaded, driven, headed, tool-deformed, or locked-thr
Headed fastener element with nut, washer, securing means or cap
Headed bolt or screw with threads and complementary nut
C411S371100, C411S542000
Reexamination Certificate
active
06244807
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a double seal nut having a first seal located within an internal bore to engage a threaded bolt and prevent leakage of fluid in an axial direction along the bolt and a second seal carried on the load bearing surface of the nut to prevent leakage in a radial direction along the interface between the load bearing surface and a workpiece upon which the load bearing surface is seated.
2. Background Art
Threaded seal nuts have long been used in industry, particularly the aerospace industry, to be mated to a correspondingly threaded bolt to hold together two typically planer and adjacent metal workpieces through which the bolt extends. It is common for a seal ring that is manufactured from a self-lubricating material (e.g. commercially known as Teflon) to be retained within a snap-in groove formed in a longitudinally extending bore through the interior of the nut. When the bolt is received within the bore of the nut, the seal ring is deformed around the threads of the bolt to prevent the leakage of fluid in a longitudinal (i.e. axial) direction along the bolt.
However, the conventional seal ring located at the interior bore of a seal nut has no effect on blocking the leakage of fluid in a radial direction along the interface between the nut and an opposing workpiece. By way of example, such liquid may be moisture originating from jet fuel carried by an aircraft. Leakage has been known to occur when an excessive torque is applied to tighten the seal nut on the bolt or as a consequence of vibrations to which the seal nut is subjected when the aircraft is in flight.
The typical solution for blocking such leakage of fluid in the radial direction is to use a sealant around the nut. In some cases, the sealant build-up is as much as ⅛ to ¼ inches thick. Not only is the process of applying the sealant expensive and time consuming, but the addition of the sealant undesirably contributes to the overall weight of the aircraft. With the large number of seal nuts used to build modern aircraft, the weight increase introduced by the volume of sealant can often be significant.
Therefore, it would be desirable for a seal nut to have the ability to prevent the leakage of fluid in both the axial direction through the internal bore of the nut and the radial direction along the bearing surface without using a sealant.
SUMMARY OF THE INVENTION
In general terms, a double seal nut is disclosed having a wrenching element to which a torquing force is applied to tighten the seal nut to a suitable bolt in order to hold together a pair of typically planer metallic workpieces that are aligned opposite one another. A washer base having a load bearing surface to be seated upon the faying surface of one of the pair of workpieces is coextensively connected to the wrenching element. An internal bore extends longitudinally through the double seal nut. The internal bore is provided with a set of screw threads that are to be mated to a correspondingly threaded bolt that extends through the pair of workpieces to be held together. A seal ring (manufactured from a self-lubricating material, such as that known commercially as Teflon) is located within a truncated conical bore formed in the internal bore of the double seal nut below the set of screw threads thereof. The seal ring is adapted to be deformed around the threads of the bolt as the double seal nut is tightened to the bolt, whereby to prevent leakage of fluid in a longitudinal (i.e. axial) direction along the bolt.
In accordance with the improvement of this invention, a sealing ring (e.g. an O-ring) is carried on the load bearing surface of the washer base of the double seal nut. The sealing ring is manufactured from an elastomeric material, such as rubber. A peripheral groove is machined or otherwise formed in the load bearing surface of the double seal nut to retain the sealing ring therewithin and surround the internal bore within which the bolt is received. Accordingly, the sealing ring prevents leakage of fluid from the internal bore in a radial direction along the interface between the load bearing surface of the double seal nut and the adjacent faying surface of the workpiece upon which the load bearing surface is seated.
REFERENCES:
patent: 3399589 (1968-09-01), Breed
patent: 4701088 (1987-10-01), Crull
patent: 5188495 (1993-02-01), Jones, Jr.
patent: 5393182 (1995-02-01), Berecz
patent: 5647710 (1997-07-01), Cushman
K-Fast Systems Engineering Drawing for 5 Point, Self-Locking, Self-Sealing Nut Drawn Mar. 16, 1999.
Bristol Industries
Fischer Morland C.
Wilson Neill
LandOfFree
Double seal nut does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Double seal nut, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Double seal nut will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2444436