Radiused lead-in for interference fit fasteners
First Claim
1. A fastener comprising:
- a head;
a shank extending from the head, the shank comprising an external surface that is circular cylindrical and having a shank diameter;
a mating portion comprising external projections; and
a transition portion disposed between the shank and the mating portion,wherein the transition portion comprises a first radiused lead-in section that meets the shank at a shank/lead-in intersection and a second radiused lead-in section that meets the first radiused lead-in section, the first radiused lead-in section curves in a first axial direction toward the mating portion for a length and has a first profile that is a circular arc having a first radius, and the second radiused lead-in section curves in the first axial direction and has a second profile that is a circular arc having a second radius which is smaller than the first radius,wherein the mating portion has a maximum diameter less than a minimum diameter of the second radiused lead-in section, andwherein the length of the first radiused lead-in section is in a range of 0.062 to 0.092 inch, the shank diameter is in a range of 6/32 to 16/32 inch, the first radius is in a range of 0.34 to 0.68 inch and the second radius is about 0.01 inch.
1 Assignment
0 Petitions
Accused Products
Abstract
An assembly comprising first and second structural elements having aligned holes, an fastener that occupies at least respective portions of the holes without a surrounding sleeve, and a mating part that is coupled to the fastener. The fastener comprises: a head; a circular cylindrical shank extending from the head; a mating portion comprising external projections; and a transition portion disposed between the shank and the mating portion. The transition portion comprises a first radiused lead-in section that meets the shank at a shank/lead-in intersection and a second radiused lead-in section that meets the first radiused lead-in section. The first radiused lead-in section curves gradually in a first axial direction toward the mating portion and has a first profile that is a circular arc having a first radius, while the second radiused lead-in section curves abruptly in the first axial direction and has a second profile that is a circular arc having a second radius which is much smaller than the first radius.
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Citations
20 Claims
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1. A fastener comprising:
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a head; a shank extending from the head, the shank comprising an external surface that is circular cylindrical and having a shank diameter; a mating portion comprising external projections; and a transition portion disposed between the shank and the mating portion, wherein the transition portion comprises a first radiused lead-in section that meets the shank at a shank/lead-in intersection and a second radiused lead-in section that meets the first radiused lead-in section, the first radiused lead-in section curves in a first axial direction toward the mating portion for a length and has a first profile that is a circular arc having a first radius, and the second radiused lead-in section curves in the first axial direction and has a second profile that is a circular arc having a second radius which is smaller than the first radius, wherein the mating portion has a maximum diameter less than a minimum diameter of the second radiused lead-in section, and wherein the length of the first radiused lead-in section is in a range of 0.062 to 0.092 inch, the shank diameter is in a range of 6/32 to 16/32 inch, the first radius is in a range of 0.34 to 0.68 inch and the second radius is about 0.01 inch. - View Dependent Claims (2, 3)
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4. An assembly comprising a first structural element having a first hole having a hole diameter, a second structural element having a second hole aligned with the first hole of the first structural element, a fastener that occupies at least respective portions of the first and second holes in the first and second structural elements without a surrounding sleeve and extends beyond the second structural element, and a mating part that abuts the second structural element and is coupled to the fastener, wherein the fastener comprises:
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a head; a shank extending from the head, the shank comprising an external surface that is circular cylindrical and having a shank diameter greater than the hole diameter; a mating portion comprising external projections; and a transition portion disposed between the shank and the mating portion, wherein the transition portion comprises a first radiused lead-in section that meets the shank at a shank/lead-in intersection and a second radiused lead-in section that meets the first radiused lead-in section, the first radiused lead-in section curves for a length in a first axial direction toward the mating portion from a maximum diameter to a minimum diameter and has a first profile that is a circular arc having a first radius, and the second radiused lead-in section curves in the first axial direction and has a second profile that is a circular arc having a second radius which is smaller than the first radius, wherein the maximum diameter of the first radiused lead-in section is greater than the hole diameter and the minimum diameter of the first radiused lead-in section is less than the hole diameter, and wherein the length of the first radiused lead-in section is in a range of 0.062 to 0.092 inch, the shank diameter is in a range of 6/32 to 16/32 inch, the first radius is in a range of 0.34 to 0.68 inch and the second radius is about 0.01 inch. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method for fastening a first structure having a first hole and a second structure having a second hole, the first and second holes having a same hole diameter, comprising:
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selecting a fastener comprising;
a head;
a shank extending from the head, the shank comprising an external surface that is circular cylindrical and having a shank diameter;
a mating portion comprising external projections; and
a transition portion disposed between the shank and the mating portion, wherein the transition portion comprises a first radiused lead-in section that meets the shank at a shank/lead-in intersection and a second radiused lead-in section that meets the first radiused lead-in section, the first radiused lead-in section curves in a first axial direction toward the mating portion for a length and has a first profile that is a circular arc having a first radius, and the second radiused lead-in section curves in the first axial direction and has a second profile that is a circular arc having a second radius which is smaller than the first radius, wherein the mating portion has a maximum diameter less than a minimum diameter of the second radiused lead-in section, and wherein the length of the first radiused lead-in section is in a range of 0.062 to 0.092 inch, the shank diameter is in a range of 6/32 to 16/32 inch, the first radius is in a range of 0.34 to 0.68 inch and the second radius is about 0.01 inch;placing the first and second structures together with the first and second holes aligned; inserting the mating portion of the fastener into the first hole until an edge of the first hole in the first structure is in contact with and surrounds the first radiused lead-in section of the fastener, the circular cylindrical shank connecting the head to the first radiused lead-in section and the shank diameter being greater than the hole diameter; forcing the fastener further into the aligned holes of the first and second structures to cause the shank to contact the edge of the first hole, push through the first hole, and then push through the second hole until the mating portion of the fastener projects beyond the second structure; and coupling a mating part to the mating portion of the fastener. - View Dependent Claims (16, 17, 18, 19, 20)
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Specification