US 4,391,544 AGranted

Self-retained fastener

AssigneeSPS Technologies, Inc.

InventorJames W. Cadwallader

Life of this patent

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Abstract

A self-retained fastener including locking means provided near the end of the fastener first inserted through a hole in a workpiece wherein the locking means becomes operative after passing beyond the hole in the workpiece. The locking means comprises an annular groove near the end of the fastener having a configuration which increases radially outwardly from a point axially inwardly from the end of the fastener toward the end of the fastener. A spring ferrule member is engaged about the end of the fastener around the annular groove and includes a portion thereof which cooperates with the exterior surface of the workpiece and the annular groove on the fastener to oppose unintentional removal of the fastener from the workpiece once it has passed through the hole in the workpiece. The ferrule also serves as a removal tool for permitting removal of the fastener when desired.

Claims8

Dependent claims

A positive lock self-retained fastener assembly for engagement in a workpiece, said fastener assembly comprising:

a pin having a shank and an end segment adjacent said shank at one end of said pin, said end segment including an annular groove disposed axially inwardly from said one end of said pin, said annular groove tapering radially outwardly from the juncture of said shank and said groove axially along said pin toward said one end to a shoulder formed axially inwardly from said one end of said pin;
and
a cup-shaped ferrule including collar means formed at the open end thereof to cooperate with said groove and engage said shoulder, thereby to slideably retain said ferrule on said pin end segment, an end wall and a substantially cylindrical wall segment extending from said end wall and terminating in said collar means, said ferrule further having an axially disposed slot formed through said collar means and a portion of said cylindrical wall segment, said slot having a sufficient length such that said collar means resiliently returns to its initial configuration after radial outward expansion thereof over said end segment and radial inward compression thereof when said ferrule is inserted in and removed from the workpiece, said ferrule being movable axially along said end segment between a first position wherein said collar means is adjacent the juncture of said shank and said groove and a second position wherein said collar means is adjacent said shoulder, said collar means being compressible in said first position to operatively allow insertion into and removal of said pin and said ferrule from the workpiece and being operative in said second position to retain said fastener in the workpiece.

A joint assembly comprising:

a workpiece assembly and a positive lock self-retained fastener assembly, said fastener assembly including a fastener member, said workpiece assembly including a bore for receiving said fastener member therethrough, said fastener member comprising a pin having a shank and an end segment adjacent said shank at one end of said pin, said pin being disposed in said bore with said end segment extending beyond the exterior surface of said workpiece assembly, said end segment including an annular groove disposed axially inwardly from said one end of said pin, said annular groove tapering radially outwardly from the juncture of said shank and said groove axially along said pin toward said one end to a shoulder formed axially inwardly from said one end of said pin, and a cup-shaped ferrule including a collar means formed at the open end thereof to cooperate with said groove and engage said shoulder, thereby to slidably retain said ferrule on said pin end segment, an end wall and a substantially cylindrical wall segment extending from said end wall and terminating in said collar means, said ferrule further having an axially disposed slot formed through said collar means and a portion of said cylindrical wall segment, said slot having a sufficient length such that said collar means resiliently returns to its initial configuration after radial outward expansion thereof over said end segment and radially inward compression thereof when said ferrule is inserted in and removed from said workpiece bore, said ferrule being movable axially along said end segment between a first position wherein said collar means is adjacent the juncture of said shank and said groove and a second position wherein said collar means is adjacent said shoulder, said collar means being compressible in said first position to operatively allow insertion into and removal of said pin and said ferrule from said workpiece bore, and being operative in said second position to cooperate with said exterior surface of said workpiece assembly and said shoulder to retain said fastener in said workpiece assembly.

Dependencies are inferred from the claim text.

Facts

Application: 05/698,669Filed 22 Jun 1976 · continuation
Priority: 16 Dec 1974
Granted: 5 Jul 1983
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

F16B 21/16
By separate parts: with grooves or notches in the pin or shaft
F16B 2200/69
Constructional details of connections not covered for in other groups of this subclass: redundant disconnection blocking means
Y10T 403/32901
Including distinct pin retainer: unitary clip or plug
F16B
Devices for fastening or securing constructional elements or machine parts together

Family

Serial533,103Parent of this continuation · filed 16 Dec 1974
US 4,391,544 AThis patent

From the US filing history. Foreign family members aren’t listed.

Timeline

Citations

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