Single side temporary fastener with constant pressure feature
A single side temporary fastener (SSTF) capable of maintaining a clamping force in a material stack subject to material creep or adjunct extrusion during clamp up processes is disclosed. The SSTF comprise a rotationally constrained but freely translatable collet body that is disposed within an auxiliary structure such as a fastener housing. A fastener comprises the aforementioned collet body, which at least partially translates within the aforementioned auxiliary structure, and further comprises a threaded screw for rotationally engaging with the collet body, which by way of an antirotation means associated therewith and with the auxiliary structure, is rotationally constrained but is free to axially translate. Constant clamping pressures are made possible in such embodiments by the inclusion of at least one biasing element between compression force transmitting elements and/or assemblies of the fasteners.
1. A temporary fastener for fastening at least two work pieces together where a portion of the fastener is disposed in substantially aligned holes or bores formed in the work pieces, the temporary fastener comprising:
a fastener housing having a first end and a second end, the second end having a bore to allow extending or retracting translational movement of a collet body within the fastener housing;
a hybrid sleeve structure comprising:
an inner sleeve embracing the second end, the inner sleeve having a sliding zone;
an outer sleeve encompassing the inner sleeve around a cooperating face, the outer sleeve having a retention end to retain the outer sleeve to the sliding zone, the sliding zone allowing the retention end sliding along the sliding zone; and
a memory ring disposed between the inner sleeve and the outer sleeve, wherein the outer sleeve includes an exterior work piece contacting surface and an interior surface that contacts the memory ring;
the memory ring enabling the outer sleeve to simultaneously translate for dampening and articulate with respect to the inner sleeve for accommodating changes in geometry of the at least two work pieces.
2. The temporary fastener of claim 1 , wherein the memory ring is a grommet.
3. The temporary fastener of claim 1 wherein the memory ring is a self-adjusting seal.
4. The temporary fastener of claim 1 , wherein the cooperating face is a partial cooperating face aligned to the translational movement direction of the collet body.
5. The temporary fastener of claim 1 , wherein the outer sleeve is manufactured from a pliable material with memory characteristics.