Patent ID: 7458245

Claim:
An apparatus for installing fasteners comprising: a drawbar having a first diameter portion, a second diameter portion, a third diameter portion, and threads disposed at a rearward end of the drawbar, the first diameter portion having an enlarged bearing head and a diameter greater than the second diameter portion, the second diameter portion having a diameter at least equal to the third diameter portion and transitioning from the first diameter portion by a shoulder, the third diameter portion transitioning from the second diameter portion by a chamfer, the chamfer of a preselected angle having no contact with an end of a piston of a fastener installation tool; an anvil having a cavity, a first aperture, and a second aperture, the first aperture being adapted to receive a portion of the first diameter portion of the drawbar; a collet having a first bore and a second bore, the first bore being adapted to receive a chuck jaw assembly for grippingly engaging fasteners, the second bore being adapted to receive the second diameter portion of the drawbar, the collet being slidably disposed within the anvil; and the drawbar having a section of the first diameter portion disposed within the first aperture, a front section of the second diameter portion threadedly engaged within the second bore of the collet, a rearward section of the second diameter portion passing through the second aperture of the anvil thereby providing a bearing surface between the rearward section of the second diameter portion and the second aperture of the anvil, and the third diameter portion passing through the second aperture of the anvil.