Patent ID: 8549724

Claim:
A fastener comprising: a body having a head, a shaft extending from the head and provided with a hollow core, and a retaining mechanism having an expanded state where the shaft is unable to be removed from a hole into which the shaft is inserted, and a contracted state where the shaft is able to pass through the hole, the retaining mechanism comprising one or more balls and respective tunnels formed radially in the shaft wherein the balls are able to move within respective tunnels, the body provided with a first opening in the head leading to the hollow core; a pin having a constant diameter portion and a contiguous tapered portion reducing in outer diameter to, and forming, a leading end of the pin, the pin being locatable in the core and being insertable into the body from the first opening and axially movable within the hollow core in a first direction toward an end of the body distant the head wherein the leading end of the pin abuts and moves the balls radially outward to a position where the balls are located partly outside their respective tunnels to place the retaining mechanism in the expanded state; and a sleeve locatable about the shaft at a position to cover the tunnels to retain the balls between the pin and the sleeve partly within and partly outside of their respective tunnels when the pin is moved to place the retaining mechanism in the expanded state, wherein the sleeve has an un-deformed state where the sleeve is passed into the hole with the shaft of the fastener and retains the balls within the shaft to lie partly in the hollow core; and an expanded state where the sleeve is expanded radially outwards when the pin is moved to place the retaining mechanism in the expanded state.