Abstract: An adjustable top jaw is provided which is attachable to a master jaw which is in turn attached to a chuck of a lathe or similar machine. The top jaw comprises a base segment, top segment drive block and a lead screw. The base segment is mountable on the master jaw. A lead screw aperture extends entirely through the base segment. A drive block slot extends downward from the top of the base segment into the base segment a distance below the lead screw aperture. The drive block is located within the drive block slot and has a first aperture extending therethrough colinearly with the lead screw aperture. The lead screw is located within the lead screw aperture and drive block aperture. The top segment is attachable to the base segment and has a drive block channel for receiving a part of the drive block. The rotation of the lead screw causes the drive block to move forward or backward thus moving the top segment forward or backward in accordance with the movement of the drive block.

Abstract: A top jaw system for securing a top jaw in position above a chuck on a milling machine, lathe or the like is provided. The system generally includes a base jaw, top jaw, master jaw, and a conventional jaw nut. The base jaw includes a bottom portion and a portion and a wedge portion. The top jaw is removably attached to the wedge portion by a pin while the bottom portion is removably attached to the jaw nut by removable mounting bolts. The jaw nut is disposed within a channel of the master jaw. The top jaw can be quickly replaced by the removable of the pin.

Abstract: A top jaw system for securing a top jaw in position above a chuck on a milling machine, lathe or the like is provided. A protrusion extends upward from the chuck and is preferably attached to the chuck by rigid attachment to a jaw nut which is positioned in a common master jaw on the chuck. The protrusion has a pair of flat faces which extends upward and over the jaw nut to form acute angles with the jaw nut. A top jaw having a slot sized to receive the protrusion is placed over the protrusion. The top jaw has a pin aperture extending through the top jaw through the slot at a right angle to the protrusion when the top jaw is placed on the protrusion. When the top jaw is placed on the protrusion, an elongated pin having a pair of flat surfaces extending along its elongated axis is placed in the pin aperture. One of the flat faces of the protrusion is pushed into contact with one of the flat surfaces of the pin.

Abstract: A top jaw system for securing a top jaw in position above a chuck on a milling machine, lathe or the like is provided. A protrusion extends upward from the chuck and is preferably attached to the chuck by rigid attachment to a jaw nut which is positioned in a common master jaw on the chuck. The protrusion has a flat face which extends upward and over the jaw nut to form an acute angle with the jaw nut. A top jaw having a slot sized to receive the protrusion is placed over the protrusion. The top jaw has a pin aperture extending through the top jaw through the slot at a right angle to the protrusion when the top jaw is placed on the protrusion. When the top jaw is placed on the protrusion, an elongated pin having a flat surface extending along its elongated axis is placed in the pin aperture. The flat face of the protrusion is pushed into contact with the flat surface of the pin. This is preferably done a set screw extending through the top jaw and contacting the protrusion opposite the flat face.