Self-clinching floating fastener
A floating fastener comprises a retainer and a captive nut held within a cavity of the retainer. The nut is star-shaped with four points spaced equally apart and with four valleys on the periphery of the nut between the points creating the overall star-shape of the nut. Likewise, the cavity in the retainer corresponds to the shape and contour of the nut but sized so that there is a substantial gap between them. Permissible lateral float of the nut can be maximized by employing a particular angularity of the sides of the valleys in relation to other dimensions of the fastener.
1. A fastener, comprising:
a retainer having a cavity defined by a peripheral inner wall, said retainer having means on an outer wall thereof for attachment to a first object;
an insert with means for attaching a second object thereto, said insert having a star-shaped periphery with a plurality of radially pointing corners and valleys, each valley located between two adjacent corners and each corner defined by the sides of two adjacent valleys which meet at a point;
wherein the shape of the retainer cavity corresponds to the shape of the insert periphery with a gap between them permitting relative lateral movement while resisting relative rotation by the interference between the insert corners and the inner wall of the retainer; and means for captivating the insert within the retainer.
2. The fastener of claim 1 wherein the means for captivating the insert is a resilient non-destructively releasable clip.
3. The fastener of claim 2 wherein the clip is circular and engages a groove in the retainer inner wall.
4. The fastener of claim 2 wherein the insert is captivated between the clip and an end wall of the retainer at the base of the cavity.
5. The fastener of claim 1 wherein the means for attaching a second object to the insert is an internally threaded bore of the insert.
6. The fastener of claim 5 wherein the amount of total lateral float is equal to the formula (R−1.5×T)/2 where R equals the retainer outer diameter and T equals the major thread diameter of the insert bore.
7. The fastener of claim 1 wherein the retainer outer wall attachment means are clinch features for receiving the cold flow of material from the first object.
8. The fastener of claim 7 wherein the retainer outer wall is circular.
9. The fastener of claim 1 wherein the means for attaching the second object to the insert comprises an externally threaded stud integral with the insert.
10. The fastener of claim 1 wherein the insert has four corners and angled planar side surfaces on opposite sides of each of the valleys defining included obtuse angles of less than 180 degrees.
11. The fastener of claim 10 wherein the included angle is approximately 169 degrees plus or minus 3 degrees.
12. The fastener of claim 10 wherein the included angles are all equal.
13. The fastener of claim 1 wherein relative rotation between the retainer and the insert is resisted by the contact between the insert peripheral corners and inwardly projecting elements on the retainer inner wall.