Helical groove fasteners and methods for making same

Abstract

Helical groove fasteners and methods for producing the same are provided for use in systems requiring fluid passage through the fastener. In one embodiment, the fastener includes a shank, a head, a threaded portion, and at least one groove extending through at least a portion of the threaded portion. The fastener can include a single groove or multiple grooves. In certain preferred embodiments, the helix rotation angle of the groove is selected so that the shank has a continuous diameter to facilitate the thread forming process. In preferred embodiments, the fastener is cold forged and the threads are formed using a thread rolling die.

Description

FIELD OF THE INVENTION [0001] The present invention relates generally to fasteners that allow fluid passage. In particular, the invention relates to fasteners with helical grooves that allow fluid to pass through at least a portion of the fastener. BACKGROUND OF THE INVENTION [0002] Fasteners that allow fluid passage are often used to connect a flexible hose firmly to a rigid member having a fluid port. In one exemplary configuration, the flexible hose is connected to a fitting within an interior volume that allows fluid to flow from the interior surface of the fitting to the hose. The interior volume of the fitting is sealed with a fastener. The top opening of the fitting is sealed by the head of the fastener and the bottom opening of the fitting is sealed by the surface of the rigid member surrounding the fluid port. Fluid can flow from the fluid port of the rigid member to the interior volume of the fitting through a passage in the fastener. [0003] Exemplary applications for such...

AI Technical Summary

Problems solved by technology

The internal drilling can reduce the tensile strength of the fastener significantly.

The drilling operation also adds expense to the production process and creates the potential for contaminants, such as metal chips and flakes, to attach to the fastener.

During use, the contaminant may dislodge and cause serious damage.

Metal flakes entering an automotive oil line, for example, can scratch the cylinder walls of the engine.

Metal chips can also become lodged in the fluid passage and create an obstruction.

An obstruction in a brake line, for example, can cause brake failure.

Linear grooves, however, create difficulties in the thread forming process resulting in defective thread formation and inefficient manufacturing processes.

Additionally, the forces exerted on the knurl during the thread forming process can create metal shavings that can result in contaminants attaching to the fastener.

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