Composite, self-sealing female fastener

Claim 2

An improved composite self-sealing female fastener comprising: a. a nut having an axial bore, female threads in the axial bore for engaging the male threads of a male fastener, an annular seal bearing surface at one axial end of the nut, and wrenching means for accepting a wrenching tool to apply a setting torque to the nut; b. a washer rotatable with respect to the nut and having an axial bore for receiving the male fastener, a sheet engaging section including an externally disposed annular sheet abutting surface for engaging a sheet of a jOint effected with the female fastener and the male fastener, the sheet abutting surface having a protruding, annulated frusto-conical section which converges towards the axis of the washer to define a portion of the sheet abutting surface bounding the washer''s axial bore which engages a sheet before any other portion of the sheet abutting surface, an internally disposed annular seal bearing surface spaced axially from the seal bearing surface of the nut, and an axially extending skirt overlying in spaced relationship an axially extending external surface of the nut to define an annular channel for receipt of excess extruded seal material; c. a seal of extrudable material disposed between the seal bearing surfaces of the nut and the washer, the seal having an axial bore for receiving the male fastener; and d. means between the skirt and the nut in the channel between them to separate seal material extruded into the channel for subsequent removal.

Claim 3

The improved self-sealing female fastener claimed in claim 1 wherein the means in the skirt to part seal material extruded into the channel into strips for subsequent removal also rotationally couples the washer to the nut concentric thereto.

Claim 4

The improved self-sealing female fastener claimed in claim 2 wherein the means recited therein is a plurality of circumferentially spaced dimples in the skirt.

Claim 5

The improved self-sealing female fastener claimed in claim 1 wherein the interior axial end of the sheet abutting section defines the seal bearing surface, such surface paralleling the sheet abutting surface, and the frusto-conical section is deformable upon the application of an axial setting load on the nut of substantially less than the rated capacity of the nut to form a flat, radially extending section for substantially complete engagement by the seal bearing surface of the nut upon completion of seal extrusion from between the two seal bearing surfaces.

Claim 6

The improved self-sealing female fastener claimed in claim 1 wherein the inner surface of the frusto-conical section defines a wall sloping away from the seal bearing surface of the nut and which forms at least a part of the washer''s seal bearing surface, and the frusto-conical section is deformable into a flat section with its internal and external surfaces being substantially normal to the axis of the nut upon the application of an axial compressive load during the fabrication of a joint substantially lower than the design preload of the nut.

Claim 7

The improved self-sealing female fastener claimed in claim 5 wherein the seal is formed of powdered Teflon.

Claim 8

The improved self-sealing female fastener claimed in claim 6 wherein the seal is compacted sufficiently to maintain its shape but not enough to form a grainless homogeneous solid.

Claim 9

The improved self-sealing female fastener claimed in claim 1 wherein there is sufficient seal material such that upon setting of the fastener seal material will extrude into and at least substantially fill interstices radially inward of the seal bearing surfaces of the nut and washer.

Claim 10

An improved composite self-sealing female fastener comprising: a. a nut having an internally threaded axial bore, a right cylindrical counterbore coaxial with and opening into the internally threaded axial bore, the counterbore extending from a seal bearing end of the nut, an annular, radially extending seal bearing surface at the seal bearing end, and means for accepting a wrenching tool for the application of a setting torque to the nut; b. a washer rotationally and concentrically coupled to the nut at the seal bearing end and having an axial bore for accepting a male fastener, an external frusto-conical sheet abutting surface protruding away from the nut to engage the surface of a sheet first at the washer''s bore, an internal frusto-conical seal bearing surface facing the seal bearing surface of the nut and progressively increasing in axial distance away from such surface with decreasing radius, the section of the washer which defines the external and internal frusto-conical surfaces being deformable in compression upon the application of an applied setting load substantially lower than the design preload of the nut to produce orientations of such external and internal surfaces which are substantially normal to the axis of the nut, means between the washer and the nut for venting excess seal material; c. a seal of extrudable material disposed between the seal bearing surfaces of the nut and the washer, the seal having an axial bore for receiving the male fastener and being capable of substantially complete extrusion from between the seal bearing surfaces with an applied axial setting load substantially lower than the design preload of the nut; and d. the venting means including an axially extending annular skirt for the washer which is spaced radially from an external surface of the nut to define therewith an annular channel for the receipt of excess extruded seal material.

Claim 11

An improved composite self-sealing female fastener comprising: a. a nut having an internally threaded axial bore, a right cylindrical counterbore coaxial with and opening into the internally threaded axial bore, the counterbore extending from a seal bearing end of the nut, an annular, radially extending seal bearing surface at the seal bearing end, and means for accepting a wrenching tool for the application of a setting torque to the nut; b. a washer rotationally and concentrically coupled to the nut at the seal bearing end and having an axial bore for accepting a male fastener, an external frusto-conical sheet abutting surface protruding away from the nut to engage the surface of a sheet first at the washer''s bore, an internal frusto-conical seal bearing surface facing the seal bearing surface of the nut and progressively increasing in axial distance away from such surface with decreasing radius, the section of the washer which defines the external and internal frusto-conical surfaces being deformable in compression upon the application of an applied setting load substantially lower than the design preload of the nut to produce orientations of such external and internal surfaces which are substantially normal to the axis of the nut, means between the washer and the nut for venting excess seal material; c. a seal of extrudable material disposed between the seal bearing surfaces of the nut and the washer, the seal having an axial bore for receiving the male fastener and being capable of substantially complete extrusion from between the seal bearing surfaces with an applied axial setting load substantially lower than the design preload of the nut; and d. the venting means including an axially extending annular skirt for the washer which is spaced radially from an external surface of the nut to define therewith an annular channel for the receipt of excess extruded seal material.

Claim 12

The improved composite self-sealing female fastener claimed in claim 9 wherein the nut includes a portion having the wrenching means, which portion is adapted to separate from the remainder of the nut upon the application of a predetermined torque to the wrenching means.

Claim 13

The improved composite self-sealing female fastener claimed in claim 9 wherein the seal is of powdered Teflon.

Claim 14

The improved composite self-sealing female fastener claimed in claim 9 including means in the channel between the skirt and the nut for separating excess extruded seal material into strips during the setting of the fastener for subsequent removal, such means providing the rotational and concentric couple between the washer and the nut.

Claim 15

An improved composite self-sealing female fastener comprising: a. a nut having i. an axial bore with internal threads along a length thereof for accepting the threads of a male fastener; ii. an axial right cylindrical counterbore of the axial bore opening into the threaded section thereof and opening at a seal bearing end of the nut, the counterbore having an axial length sufficient to accommodate a predetermined grip variation and thread run-out of the male fastener and a diameter sufficient to accommodate a tapered or oversized shank of the male fastener; iii. an annular, radially extending seal bearing surface at the seal bearing end and bounding the counterbore; iv. an axially extending external annular surface on the seal bearing end and bounding the counterbore; and v. wrenching means for accepting a wrenching tool to apply a setting torque to the nut; and b. a washer having i. an axial bore for accepting the male fastener; ii. an annular frusto-conical section bordering the washer''s axial bore and protruding away from the seal bearing surface of the nut, the frusto-conical section defining a conical external sheet abutting surface and a conical internal seal bearing surface, the latter surface facing in the direction of the nut''s seal bearing surface, the frusto-conical section being deformable under compressive load to become essentially flat at an applied axial setting load substantially below the total required load of the nut; iii. an axial extending annular skirt integrally connected with the frusto-conical section and spaced radially from the external annular surface of the seal bearing end of the nut to define therewith an annular axially extending channel; and iv. means in the skirt for rotatably coupling the washer concentrically to the nut, such means extending into the annular channel between the seal bearing end and the skirt to also separate extruded seal material passing by such means from the balance of the seal for removal; and c. a seal of material which flows freely under compressive load having an axial bore for accepting a male fastener and being disposed between the seal bearing surfaces of the nut and the washer, the seal being capable of substantially complEte extrusion from between these seal bearing surfaces at an applied axial setting load substantially below the rated axial load of the nut and of substantially increasing its resistance to flow under compressive load at loads approaching the rated axial load of the nut.

Claim 16

An improved composite self-sealing female fastener comprising: a. a nut having i. an axial bore with internal threads along a length thereof for accepting the threads of a male fastener; ii. an axial right cylindrical counterbore of the axial bore opening into the threaded section thereof and opening at a seal bearing end of the nut, the counterbore having an axial length sufficient to accommodate a predetermined grip variation and thread run-out of the male fastener and a diameter sufficient to accommodate a tapered or oversized shank of the male fastener; iii. an annular, radially extending seal bearing surface at the seal bearing end and bounding the counterbore; iv. an axially extending external annular surface on the seal bearing end and bounding the counterbore; and v. wrenching means for accepting a wrenching tool to apply a setting torque to the nut; and b. a washer having i. an axial bore for accepting the male fastener; ii. an annular frusto-conical section bordering the washer''s axial bore and protruding away from the seal bearing surface of the nut, the frusto-conical section defining a conical external sheet abutting surface and a conical internal seal bearing surface, the latter surface facing in the direction of the nut''s seal bearing surface, the frusto-conical section being deformable under compressive load to become essentially flat at an applied axial setting load substantially below the total required load of the nut; iii. an axial extending annular skirt integrally connected with the frusto-conical section and spaced radially from the external annular surface of the seal bearing end of the nut to define therewith an annular axially extending channel; and iv. means in the skirt for rotatably coupling the washer concentrically to the nut, such means extending into the annular channel between the seal bearing end and the skirt to also separate extruded seal material passing by such means from the balance of the seal for removal; and c. a seal of material which flows freely under compressive load having an axial bore for accepting a male fastener and being disposed between the seal bearing surfaces of the nut and the washer, the seal being capable of substantially complEte extrusion from between these seal bearing surfaces at an applied axial setting load substantially below the rated axial load of the nut and of substantially increasing its resistance to flow under compressive load at loads approaching the rated axial load of the nut.

Claim 17

The improved composite self-sealing fastener claimed in claim 13 wherein the seal is of powdered Teflon.

Claim 18

The improved composite self-sealing fastener claimed in claim 14 wherein the separation and coupling means includes a plurality of circumferentially spaced-apart protrusions formed in the skirt and extending radially inwardly for engagement of the external surface of the nut, the protrusions rotatably coupling the washer to the nut.

Claim 19

An improved composite self-sealing female fastener comprising: a. a nut having an axial bore, female threads formed in the axial bore, an annular radially extending seal bearing surface at a seal bearing end of the nut, and an annular external surface for receiving a wrenching member; b. a washer rotatably coupled to the nut at the seal bearing end thereof and having an axial bore for accepting a male fastener, an externally protruding, frusto-conical section bounding the washer''s axial bore defining at least a portion of an internal seal bearing surface and at least a portion of an external sheet abutting surface, the external sheet abutting surface and the internal seal bearing surface being spaced axially from the seal bearing surface of the nut; c. a seal of extrudable material disposed between the seal bearing surfaces of the nut and the washer, the seal having an axial bore for receiving the male fastener and being capable of substantially complete extrusion from between the seal bearing surfaces with an applied axial setting load substantially below the maximum design load of the nut; d. the washer having an axially extending skirt in overlying spaced relationship with the nut at the seal bearing end thereof to define therewith an annular channel for receiving excess extruded seal material and including means formed in the wall of the skirt to separate excess extruded material in the channel into strips with the setting of the fastener; and e. a wrenching member disposed on the wrenching member receiving surface of the nut and in nonrotatable engagement therewith, the engagement between the wrenching member and the nut being such that upon the application of a predetermined wrenching torque on the wrenching member, the wrenching member separates from the nut.

Claim 20

An improved composite self-sealing female fastener comprising: a. a nut having an axial bore, female threads formed in the axial bore, an annular radially extending seal bearing surface at a seal bearing end of the nut, and an annular external surface for receiving a wrenching member; b. a washer rotatably coupled to the nut at the seal bearing end thereof and having an axial bore for accepting a male fastener, an externally protruding, frusto-conical section bounding the washer''s axial bore defining at least a portion of an internal seal bearing surface and at least a portion of an external sheet abutting surface, the external sheet abutting surface and the internal seal bearing surface being spaced axially from the seal bearing surface of the nut; c. a seal of extrudable material disposed between the seal bearing surfaces of the nut and the washer, the seal having an axial bore for receiving the male fastener and being capable of substantially complete extrusion from between the seal bearing surfaces with an applied axial setting load substantially below the maximum design load of the nut; d. the washer having an axially extending skirt in overlying spaced relationship with the nut at the seal bearing end thereof to define therewith an annular channel for receiving excess extruded seal material and including means formed in the wall of the skirt to separate excess extruded material in the channel into strips with the setting of the fastener; and e. a wrenching member disposed on the wrenching member receiving surface of the nut and in nonrotatable engagement therewith, the engagement between the wrenching member and the nut being such that upon the application of a predetermined wrenching torque on the wrenching member, the wrenching member separates from the nut.

Claim 21

The improved composite self-sealing female fastener claimed in claim 16 wherein the engagement between the wrenching member and the nut is effected through splines, and the wrenching member engagement surface of the nut is frusto-conical with the base of the section being towards the sheet abutting end of the fastener, and the wrenching member has a right cylindrical bore before engaging the frusto-conical surface which is at least partially deformed to conform to the frusto-conical wrenching member engagement surface along a predetermined length of the wrenching member''s bore to effect a predetermined engagement area for controlling the value at which the wrenching member separates from the nut.