US 4,752,993 A · Fastener and method of attachment to sheet material

Abstract

A fastener and method of attachment of such fastener to sheet material to provide attachment of a tubular fastener to the sheet material by extruding, without severing, portions of the sheet material completely through openings on the base portion of the fastener. In one embodiment of the invention, the extruded material is clinched on the top surface of the base portion by clinch members integrally formed with the base portion. The fastener is internally threaded, lightweight and preferably heat-treated prior to attachment to the sheet material to provide fastener strength equivalent to or greater than that of much heavier nuts. Two types of such fasteners may be attached by a method which opens up a hole in the sheet material of a larger diameter than the major diameter of the threads in the fasteners while simultaneously clinching the fastener in place. This eliminates the need to use thread-cutting bolts. The fasteners may be connected together to form a strip to be fed into an automated assembly unit from a dispenser. In another embodiment of the invention, the extruded material is clinched on the top surface by extruding it through clinch openings into the cavities of a die member that is brought into contact with the top surface of the fastener, each such cavity being aligned with and being somewhat larger than the clinch opening of the fastener that it is adjacent to.

Claims17

Dependent claims

A method for attaching at least one fastener to sheet material, said fastener including a base portion having top and bottom surfaces, said base portion including a pair of spaced clinch members integrally formed therewith to define a pair of spaced clinch openings in said bottom surface of said base member and a pair of spaced extrusion openings in said top surface in fluid communication with said clinch openings, said fastener further including a tubular attachment portion integrally formed with said base portion between said clinch members and adapted for attachment to a separate fastener, said method comprising the steps of:

placing said fastener on said sheet material so that said bottom surface of said base portion abuts said sheet material;
punching out a slug of sheet material to leave a hole in said sheet material, said hole having its center on a line forming a longitudinal axis of said tubular attachment portion;
and
extruding portions of said sheet material surrounding said hole into said clinch openings and through said extrusion openings substantially simultaneously with said steps of punching to effect an attachment of said fastener to said sheet material at said top surface of said base portion without severing said portions of sheet material.

1 more element

A method for attaching a fastener to drawable sheet material having opposed surfaces, said fastener including a base portion having top and bottom surfaces, a neck portion and a portion connecting said neck portion to said base portion, said base portion including at least one clinch opening having an edge therein, said method comprising the steps of:

placing said fastener on said sheet material so that said bottom surface of said base portion abuts one of said opposed surfaces of said sheet material;
bringing a die having a cavity into contact with said top surface of said base portion of said fastener, said cavity being aligned with said at least one clinch opening and being at least slightly larger than said at least one clinch opening;
and
extruding a portion of said base portion of said drawable sheet material through said at least one clinch opening into said cavity to cause said portion of said base portion of said drawable sheet material to expand beyond said edge of said at least one clinch opening and to thereby secure said fastener to said drawable sheet material, said extruding being accomplished without any severing of said portion of said base portion of said drawable sheet material.

1 more element

A method of attaching a fastener to drawable sheet material having opposed surfaces, said fastener including a base portion having top and bottom surfaces, a neck portion and a portion connecting said neck portion to said base portion, said base portion including first and second clinch openings, each of which has an edge, said neck portion being disposed between said first and second clinch openings, said method comprising the steps of:

placing said fastener on said sheet material so that said bottom surface of said base portion abuts one of said opposed surfaces of said sheet material;
bringing a die having first and second cavities into contact with said top surface of said base portion of said fastener, said first cavity being aligned with said first clinch opening and being at least slightly larger than said first cavity, said second cavity being aligned with said second clinch opening and being at least slightly larger than said second clinch opening;
and
extruding first and second portions of said base portion of said drawable sheet material, respectively, through said first and second clinch openings into said first and second cavities of said die to cause said first and second portions of said base portion to expand beyond the edges of said first and second clinch openings, respectively, and to thereby secure said fastener to said drawable sheet material at the locations of said first and second clinch openings of said fastener, said extruding being accomplished without any severing of said first and second portions of said base portion of said drawable sheet material.

1 more element

Dependencies are inferred from the claim text.

Fastener and method of attachment to sheet material

Life of this patent

Fastener and method of attachment to sheet material

Life of this patent

Abstract

Claims17