Serviceable fastener with a removable head

1. A fastener comprising:

a) a body having:

i) a first cylindrical portion with a first diameter and having an exterior threaded portion,

ii) a second cylindrical portion with a second diameter,

iii) a shoulder formed between the first cylindrical portion and the second cylindrical portion due to a difference in the first diameter and the second diameter, and

iv) a body hole extending along an axis of the body through both the first cylindrical portion and the second cylindrical portion;

b) a mandrel having:

i) a mandrel shank, and

ii) a mandrel head at an end of the mandrel shank; and

c) a fastener head having:

i) an opening defined by an interior threaded portion; and

ii) one or more head protrusions on a surface facing toward the mandrel head and configured to embed into a first panel;

iii) a centering feature formed as a protrusion facing toward the mandrel head and configured to align the fastener with a first panel hole of the first panel;

wherein the mandrel shank at least partially occupies the body hole;

wherein the mandrel head is located outside of the body and opposite of the exterior threaded portion of the body;

wherein the exterior threaded portion of the body and the interior threaded portion of the fastener head are engaged to removably secure the body to the fastener head; and

wherein the fastener is configured to be deformed from an undeformed state into a deformed state.

2. The fastener of claim 1 , wherein in the deformed state, a deformed area results on the body after the mandrel shank of the mandrel opposite of the mandrel head is pulled axially such that the mandrel head is pulled toward the fastener head.

3. The fastener of claim 2 , wherein the first cylindrical portion of the body occupies the first panel hole in the first panel, and the second cylindrical portion of the body occupies a second panel hole in a second panel; and

wherein the second panel hole in the second panel is smaller in diameter than the first diameter of the first cylindrical portion of the body.

4. The fastener of claim 3 , wherein when the fastener is in the deformed state, the second panel is permanently mechanically constrained between the shoulder of the body and the deformed area of the body.

5. The fastener of claim 4 , wherein when the fastener is in the deformed state, the first panel is removably constrained between the fastener head and the second panel due to the fastener head being removably secured to the body.

6. The fastener of claim 5 , wherein the first panel is removable from the second panel and the body by applying torque to the fastener head until the fastener head rotates relative to the body and is separated from the body by the interior threaded portion disengaging from the exterior threaded portion.

7. The fastener of claim 6 , wherein the first panel is removably re-constrained to the body and the second panel by rotating the fastener head relative to the body and applying torque to the fastener head until the fastener head and the body are mechanically constrained by reengaging the interior threaded portion with the exterior threaded portion.

8. The fastener of claim 2 , wherein the mandrel breaks into two pieces at the mandrel shank at a break point due to additional axial pulling force on the mandrel shank after a creation of the deformed area.

9. The fastener of claim 1 , wherein the body has an external surface texture along the first cylindrical portion, the second cylindrical portion, or both and the surface texture is a knurl, ribbing, or a combination thereof.

10. The fastener of claim 1 , wherein the fastener head has a hexagonal, a quadrangular, or other polygonal perimeter.

11. The fastener of claim 1 , wherein the fastener is made of steel, aluminum, brass, or any alloy thereof.

12. The fastener of claim 1 , wherein the centering feature is a cylindrical protrusion from the fastener head and has an outer diameter smaller than the first panel hole.

13. A process for removably affixing a first panel to a second panel using a fastener, wherein the fastener comprises:

a) a body having a first cylindrical portion with a first diameter, a second cylindrical portion with a second diameter, a shoulder between the first cylindrical portion and the second cylindrical portion, an exterior threaded portion part of the first cylindrical portion, and a body hole extending along an axis of the body;

b) a mandrel having a mandrel shank and a mandrel head at an end of the mandrel shank; and

c) a fastener head having an opening defined by an interior threaded portion, one or more head protrusions on a surface facing toward the mandrel head and configured to embed into the first panel, and a centering feature formed as a protrusion facing toward the mandrel head and configured to align the fastener with a first panel hole of the first panel;

wherein the mandrel shank at least partially occupies the body hole;

wherein the mandrel head is located outside of the body and opposite of the exterior threaded portion of the body; and

wherein the exterior threaded portion of the body and the interior threaded portion of the fastener head are engaged to removably secure the body to the fastener head;

wherein the process comprises the steps of:

1) coaxially aligning the first panel hole in the first panel with a second panel hole in the second panel while the first panel and the second panel are in contact with each other;

2) inserting the body of the fastener through the first panel hole in the first panel and the second panel hole in the second panel with the fastener head adjacent to the first panel; and

3) deforming the fastener such that a deformed area of the body is created by axially pulling the mandrel that extends axially through the body on a side opposing the mandrel head such that the mandrel head creates the deformed area by compressing and plastically deforming the body, wherein the body constrains the second panel between the deformed area and the shoulder of the fastener and the first panel is constrained between the second panel and the fastener head.

14. The process of claim 13 , additionally comprising the steps of:

4) removing the fastener head from the body by applying torque to the fastener head sufficient to release the fastener head from the body via a threaded portion of the fastener head and the body;

5) removing the first panel from the second panel while the body of the fastener remains permanently affixed to the second panel;

6) re-inserting the body of the fastener into the first panel hole; and

7) re-engaging the threaded portion of the fastener head and the body and applying torque sufficient to mechanically constrain the first panel to the second panel.

15. A panel assembly comprising:

a) a first panel having a first panel hole;

b) a second panel having a second panel hole; and

c) a fastener comprising:

i) a body having:

A) a first cylindrical portion with a first diameter and having an exterior threaded portion,

B) a second cylindrical portion with a second diameter,

C) a shoulder between the first cylindrical portion and the second cylindrical portion due to a difference in the first diameter and the second diameter,

D) a cylindrical hole extending along an axis of the body through both the first cylindrical portion and the second cylindrical portion;

ii) a mandrel having:

A) a mandrel shank, and

B) a mandrel head at an end of the mandrel shank; and

iii) a fastener head having:

A) an opening defined by an interior threaded portion; and

B) one or more head protrusions on a surface facing toward the mandrel head and embedded into the first panel;

C) a centering feature formed as a protrusion facing toward the mandrel head and which aligns the fastener with the first panel hole of the first panel;

wherein the mandrel shank at least partially occupies the cylindrical hole of the body;

wherein the mandrel head is located outside of the body and opposite of the exterior threaded portion of the body;

wherein the exterior threaded portion of the body and the interior threaded portion of the fastener head are engaged to removably secure the body to the fastener head;

wherein the fastener is configured to be deformed from an undeformed state into a deformed state and secures the first panel to the second panel in the deformed state;

wherein in the deformed state, a deformed area results on the body when the mandrel shank opposite of the mandrel head is pulled axially such that the mandrel head is pulled toward the fastener head;

wherein the first cylindrical portion of the body occupies the first panel hole in the first panel and the second cylindrical portion of the body occupies the second panel hole in the second panel;

wherein the second panel hole is smaller in diameter than the first diameter of the first cylindrical portion of the body;

wherein the second panel is permanently mechanically constrained between the shoulder of the body and the deformed area of the body; and

wherein the first panel is removably constrained between the fastener head and the second panel.

16. The panel assembly of claim 15 , wherein the first panel is removable from the second panel and the body by applying torque to the fastener head until the fastener head rotates relative to the body and is separated from the body by the interior threaded portion disengaging from the exterior threaded portion.

17. The panel assembly of claim 16 , wherein the first panel is removably re-constrained to the body and the second panel by rotating the fastener head relative to the body and applying torque to the fastener head until the fastener head and the body are mechanically constrained by reengaging the interior threaded portion with the exterior threaded portion.

18. The panel assembly of claim 15 , wherein the mandrel breaks into two pieces at the mandrel shank at a reduced mandrel diameter zone due to additional axial pulling force on the mandrel shank after the creation of the deformed area.

19. The panel assembly of claim 15 , wherein the body has an external surface texture along the first cylindrical portion, the second cylindrical portion, or both and the surface texture is a knurl, ribbing, or a combination thereof.

20. A panel assembly comprising:

a) a first panel having a first panel hole;

b) a second panel having a second panel hole aligned with the first panel hole; and

c) a fastener comprising:

i) a body having:

A) a first cylindrical portion with a first diameter and having an exterior threaded portion,

B) a second cylindrical portion with a second diameter,

C) a shoulder formed between the first cylindrical portion and the second cylindrical portion due to the difference in the first diameter and the second diameter,

D) a cylindrical hole extending along an axis of the body through both the first cylindrical portion and the second cylindrical portion;

ii) a mandrel having:

A) a mandrel shank, and

B) a mandrel head at an end of the mandrel shank; and

iii) a fastener head having:

A) an opening defined by an interior threaded portion; and

B) one or more head protrusions on a surface facing toward the mandrel head and embedded into the first panel;

C) a centering feature formed as a protrusion facing toward the mandrel head which aligns the fastener with the first panel hole of the first panel;

wherein the mandrel shank at least partially occupies the cylindrical hole of the body;

wherein the mandrel head is located outside of the body and opposite of the exterior threaded portion of the body;

wherein the exterior threaded portion of the body and the interior threaded portion of the fastener head are engaged to removably secure the body to the fastener head;

wherein the fastener is configured to be deformed from an undeformed state into a deformed state and secures the first panel to the second panel in the deformed state;

wherein in the deformed state, a deformed area results on the body when the mandrel shank opposite of the mandrel head is pulled axially such that the mandrel head is pulled toward the fastener head;

wherein the mandrel breaks into two pieces at the mandrel shank at a reduced mandrel diameter zone due to additional axial pulling force on the mandrel shank after a creation of the deformed area;

wherein the first cylindrical portion of the body occupies the first panel hole in the first panel, and the second cylindrical portion of the body occupies the second panel hole in the second panel;

wherein the second panel hole is smaller in diameter than the first diameter of the first cylindrical portion of the body;

wherein the body has an external surface texture along the first cylindrical portion, the second cylindrical portion, or both, and the external surface texture is a knurl, ribbing, or a combination thereof;

wherein the second panel is permanently mechanically constrained between the shoulder of the body and the deformed area of the body;

wherein the first panel is removably constrained between the fastener head and the second panel;

wherein the first panel is removable from the second panel and the body by applying torque to the fastener head until the fastener head rotates relative to the body and is separated from the body by the interior threaded portion disengaging from the exterior threaded portion; and

wherein the first panel is removably re-constrained to the body and the second panel by rotating the fastener head relative to the body and applying torque to the fastener head until the fastener head and the body are mechanically constrained by reengaging the interior threaded portion with the exterior threaded portion.