Crowned solid rivet

• US 5,580,202 A
• Filed: 04/13/1995
• Issued: 12/03/1996
• Est. Priority Date: 04/13/1995
• Status: Expired due to Term

• Current Assignee: Allfast Fastening Systems Incorporated (TriMas Corporation)
• Original Assignee: Allfast Fastening Systems Incorporated (TriMas Corporation)
• Inventors: Luhm, Ralph
• Primary Examiner(s): Wilson, Neill R.
• Application Number:
  US08/422,131
• Time in Patent Office: 600 Days
• Field of Search: 411/501, 411/504, 411/505, 411/506, 411/507, 29/524.1
• US Class Current: 411/507
• CPC Class Codes: B21J 15/02 Riveting procedures
• CPC Class Codes: F16B 19/06 Solid rivets made in one piece
• CPC Class Codes: Y10T 29/49943 Riveting

Abstract

A rivet which has a flat crown that extends from the head of a rivet. The rivet is typically installed into a workpiece hole which has a countersink. The head has a frusto-conical section that extends from a rivet shank and a cylindrical section that extends from the frusto-conical section. The frusto-conical section sits within a countersink of the workpiece hole. Extending from a top surface of the head is a crown which has a flat end face and a tapered portion that extends from the end face to the top head surface. The crown has a diameter that is smaller than the outer diameter of the head. The flat end face is approximately 0.5 times the diameter of the shank. The crown has a diameter that is approximately 1.25 times the shank diameter. The rivet is deformed by a hammer and an anvil so that the crown becomes flat and the rivet fills the hole of the workpiece. The crown maintains essentially the same diameter during the rivet deformation process so that the deformation forces are transmitted primarily through the shank of the rivet. The rivet head completely fills the workpiece hole without requiring any post-installation shaving process.

Claims

1. A rivet, comprising:

a shank that has a shank diameter; and

,

a head that extends from said shank, said head having a crown that includes a flat end face and a tapered surface that extends to a top surface of said head, said crown having a crown diameter that is approximately 1.25 times said shank diameter, said flat end face has a diameter that is approximately 0.5 times said shank diameter.

2. The rivet as recited in claim 1, wherein said crown has a height from said top surface that is approximately 0.03 times the shank diameter.

3. The rivet as recited in claim 1, wherein said head has a frusto-conical section that extends from said shank and a cylindrical section that extends from said frusto-conical section.

4. The rivet as recited in claim 1, wherein said tapered surface of said crown has a convex radius.

5. A method for installing a rivet into a workpiece, comprising the steps of:

a) inserting a rivet into a hole of a workpiece, wherein said rivet includes a shank that has a shank diameter and a head that extends from said shank, said head having a crown that includes a flat end face and a tapered surface that extends from said flat end face to a top surface of said head, said crown having a crown diameter that is approximately 1.25 times said shank diameter, said flat end face has a diameter that is approximately 0.5 times said shank diameter; and

,

b) deforming said rivet to expand said head and said shank and to create an interference fit between the workpiece and said rivet.

6. A method for installing a rivet into a workpiece which has a hole, wherein the hole has a countersink section that is adjacent to a cylindrical section, comprising the steps of:

a) inserting a rivet into the hole of the workpiece, wherein said rivet has a shank that has a shank diameter and which is inserted into the cylindrical section of the hole, a head which has a cylindrical section and a frusto-conical section that is inserted into the countersink section of the hole, said head having a crown that includes a flat end face and a tapered surface that extends from said flat end face to a top surface of said head, said crown having a crown diameter that is approximately 1.25 times said shank diameter, said flat end face has a diameter that is approximately 0.5 times said shank diameter; and

,

b) deforming said rivet to expand said head and said shank and to create an interference fit between the workpiece and said rivet.