# US 4,400,123 A · Nut and thread protector > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,400,123 A - Document ID: US4400123A - Status: Granted - Kind: A - Application number: 06/168,504 - Filed: 1980-07-14 - Granted: 1983-08-23 - Earliest claimed: 1980-07-14 - Assignees: Rodun Development Corporation - Inventors: Ronald G. Dunegan - Web page: https://patentgrep.com/patent/US4400123A ## CPC - F16B 37/14: Cap nuts; Nut caps or bolt caps - F16B 2200/89: Use of a hydraulic action - Y10S 411/91: Antitamper means - F16B: DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING (couplings for transmitting rotation F16D) - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract Methods and apparatus are provided for protecting nuts and protruding threads of bolts from corrosion and damage. A cup-shaped cap is provided for sealingly enclosing the exposed threads. A suitable protecting fluid may be introduced through a charging port, and an expandable bladder protruding from the side of the cap indicates that the cap is maintaining the protective fluid under pressure. A nut cover is slidably mounted to the cap, and serves to protect the nut from the environment. ## Claims ### Claim 1 Apparatus for protecting threads from the environment, comprising: a body member having a circular opening at one end thereof approximating the diameter of said threads and a cavity for receiving said threads, retaining means on said body member for fixedly positioning said body member over said threads, sealing means adjoining said opening for sealing said cavity from the environment, and valve means carried by said body member for introducing a selected fluid under pressure into said cavity and into fluid engagement with said threads. ### Claim 2 (depends on 1) The apparatus recited in claim 1, further comprising: a flexible bladder member secured to said body member for maintaining pressure within said cavity within a preselected pressure range. ### Claim 3 (depends on 1) The apparatus recited in claim 1, wherein said retaining means includes internal threads on said body for threaded engagement with said threads. ### Claim 4 (depends on 2) The apparatus recited in claim 2, wherein said valve means comprises: a leaf spring positioned within said cavity, and a stopper positioned on said leaf spring for sealing engagement with an aperture within said body member. ### Claim 5 (depends on 1) The apparatus recited in claim 1 wherein said threads protrude outwardly from a nut threaded onto said threads, said apparatus further comprising: a hexagonal-shaped nut cover slidably mounted on said body for covering a substantial portion of said nut. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein said body is cup-shaped, and said sealing means comprises an annular O-ring located adjacent the lip of said cup-shaped body. ### Claim 7 (depends on 1) Apparatus recited in claim 1, wherein said valve means comprises: a stopper for sealing engagement with an aperture within said body member, and spring means for biasing said stopper toward said aperture. ### Claim 8 (depends on 2) The apparatus as recited in claim 2, wherein said flexible bladder member covers an aperture within said body member and expands to provide an indication of fluid pressure within said cavity. ### Claim 9 (depends on 1) The apparatus as recited in claim 1, wherein said sealing means is in engagement with a portion of said threads for sealing said cavity from the environment. ### Claim 10 (depends on 5) The apparatus as recited in claim 5, wherein said sealing means is in engagement with said nut for sealing said cavity from the environment. ### Claim 11 Apparatus for protecting threads from the environment, comprising: enclosure means having an opening at the end thereof and a cavity for receiving said threads, sealing means adjacent said opening for sealing said cavity from the environment when said enclosure means is positioned over said threads, a pressure vessel within said cavity for containing a pressurized fluid including a selected gas, and actuation means for rupturing said pressure vessel while enclosure means has been positioned over said threads and said cavity has been sealed from the environment. ### Claim 12 (depends on 11) The apparatus of claim 11, further comprising a flexible bladder responsive to pressure within said cavity for providing an indication of fluid pressure within said cavity, and a nut cover mounted on said enclosure means for covering a substantial portion of a nut threaded onto said threads. ### Claim 13 (depends on 11) The apparatus of claim 11, wherein said activation means for rupturing said pressure vessel includes a pointed member for selective engagement with said pressure vessel. ### Claim 14 (depends on 12) The apparatus as recited in claim 12, wherein said flexible bladder covers an aperture within said enclosure means for maintaining pressure within the cavity within a preselected pressure range. ### Claim 15 A method for protecting threads of a bolt from the environment, comprising sealing said threads from the environment with an enclosure, thereafter injecting a selected fluid through said enclosure and into contact with said threads, retaining said selected fluid under pressure within said enclosure for inhibiting corrosion. ### Claim 16 (depends on 15) The method of claim 15, further comprising detecting the level of fluid pressure within said enclosure. ### Claim 17 (depends on 15) The method as recited in claim 15, further comprising: providing an expandable member secured to said enclosure for maintaining said selected fluid within a preselected pressure range within said enclosure. ### Claim 18 A method for protecting threads from the environment, comprising: providing a pressurized vessel containing a selected fluid within an enclosure, sealing said threads from the environment with said enclosure, thereafter rupturing said pressurized vessel within said enclosure for releasing said selected fluid into contact with said threads, retaining said selected fluid under pressure within said enclosure for inhibiting corrosion. ### Claim 19 (depends on 18) The method of claim 18, further comprising: maintaining said selected fluid within a preselected pressure range within said enclosure.