Mechanical interlock connection of threaded fasteners to brittle materials
A fastener can include a body, an engagement feature, and a protrusion extending from the body. The engagement feature can receive and mechanically engage with a fixing member. The fastener can be positioned in a cavity of a brittle article, the cavity including an undercut region. A fixing member can pass through an aperture of a component positioned relative to the fastener such that the fixing member mechanically engages the fastener and a surface of the protrusion engages with an opposing surface of the undercut region.
1. An electronic device, comprising:
a ceramic article having a first surface, the ceramic article defining a cavity extending into the ceramic article from the first surface, the ceramic article including an undercut region defined by a retaining surface, the ceramic article including a second surface defining an opening extending tangentially into and bisecting the cavity;
a fastener disposed in the undercut region, the fastener including a body defining a securing cavity extending into the body, a channel forming a curved transition between the body and the engagement surface, and a protrusion having an engagement surface extending from the body, the engagement surface engaged with the retaining surface;
a component defining an aperture, the aperture being aligned with the securing cavity; and
a fixing member passing through the aperture and mechanically engaged with the securing cavity.
2. The electronic device of claim 1 , wherein the ceramic article comprises zirconia or alumina.
3. The electronic device of claim 1 , wherein the fastener comprises a metal.
4. The electronic device of claim 1 , wherein a portion of the body defining the securing cavity includes an engagement feature.
5. The electronic device of claim 4 , wherein the fixing member includes an engagement feature corresponding to the engagement feature of the fastener.
6. The electronic device of claim 1 , wherein the fastener has a cross-sectional area that substantially corresponds to a shape of the opening.
7. The electronic device of claim 1 , wherein the protrusion extends substantially entirely around the body.
8. The electronic device of claim 1 , wherein the fastener includes a circumferential channel in the body adjacent to the protrusion.
9. The electronic device of claim 1 , wherein radius of curvature is between about 0.001 mm and about 0.1 mm.
10. The electronic device of claim 1 , wherein:
the surface of the protrusion is in substantially flat contact with the retaining surface defining the undercut region; and
the retaining surface is oriented parallel to the first surface.
11. The electronic device of claim 1 , wherein the securing cavity extends entirely through the fastener and the fixing member extends through the fastener and into the ceramic article.
12. A fastener, comprising:
a body having a first surface and a second surface;
the body defining a cavity extending into the body from an opening in the first surface, a portion of the body defining the cavity configured to receive and engage with a fixing member;
a protrusion extending from the second surface of the body and having an engagement surface; and
the body defining a channel at an interface between the protrusion and the body, the channel forming a curved transition between the body and the engagement surface.
13. The fastener of claim 12 , wherein the portion of the body defining the cavity includes an engagement feature.
14. The fastener of claim 12 , wherein the protrusion extends substantially entirely around the body.
15. The fastener of claim 12 , wherein the protrusion extends at least partially around the body.
16. The fastener of claim 12 , wherein:
the body is substantially cylindrical; and
the engagement surface is substantially parallel with the first surface.
17. An assembly, comprising:
a brittle article defining a cavity, the brittle article including an undercut surface defining an undercut region of the cavity;
a fastener disposed in the undercut region and including an engagement feature extending into a body, a retaining surface, and a channel forming a curved transition between the body and the retaining surface, the retaining surface opposing and engaged with the undercut surface;
a component defining an aperture; and
a fixing member passing through the aperture and mechanically engaged with the engagement feature.
18. The assembly of claim 17 , wherein the component is an internal component of an electronic device.
19. The assembly of claim 17 , wherein the brittle article includes a ceramic material.
20. The assembly of claim 17 , wherein the retaining surface is in substantially flat contact with the undercut surface.