An apparatus and method for assigning drill holes. The apparatus is arranged to determine a forthcoming position of a bottom of a new drill hole before it is drilled. The forthcoming position of the drill hole bottom is determined on the basis of the current location and direction of a tool and a planned length of the drill hole.

A low pressure shut off for a pneumatic tool. The tool may include an air path for input air. A shaft may be positioned along the air path and movable relative to the air path between a first position and a second position. First and second pistons may be spaced axially apart along the shaft and each may extend radially outward beyond the shaft. In the first position, the first piston may extend across the air path to block the air path. In the second position, the second piston may be positioned to be acted on by air from a secondary inlet to apply a force to the second piston that overcomes a biasing force and positions the first piston to allow air to flow along the air path.

Positive feed tools that include gear heads configured to be driven by a motor. The gear heads further include a pneumatic manifold that provides for access to input/output signals to add on additional components that include additional air logic functionality. The gear head includes first and second interface positions. Each interface is configured to receive either the motor for powering the gear head or an add-on component to provide additional functionality to the tool.

Positive feed tools that include gear heads configured to be driven by a motor. The gear heads further include a pneumatic manifold that provides for access to input/output signals to add on additional components that include additional air logic functionality. The gear head includes first and second interface positions. Each interface is configured to receive either the motor for powering the gear head or an add-on component to provide additional functionality to the tool.

Feed tools and methods of use for initiating a change in a spindle feed direction from an advance direction that moves the spindle towards a workpiece to a retract direction that moves the spindle away from the workpiece. The tool and methods may use a thrust overload force that is generated on one or more of the components to initiate the shift from forward to retract and/or a lift ring that acts on one or more of the components. The tool and methods may also include a two-stage piston to accomplish the shift. The various components may be used independently or in combination within the tool.

Positive feed tools and methods of use that include a spindle with a distal end configured to receive a tool bit. The spindle is movable in a forward direction for the tool bit to act on a workpiece, and a retract direction to move the tool bit away from the workpiece. The spindle is configured to retract to a home position at which an air motor that drives the spindle is shut off. The feed tool includes a clutch to prevent jamming of the spindle at the home position in the event the air motor is not shut off at the proper time.

A positive feed tool that includes a spindle that is axially moved along a feed path to perform work on a workpiece. The tool includes a gear head with a plurality of gears configured to rotate and axially move the spindle. The gear head is designed to change the changing gears within the gear head to change feed rates on the spindle. The gears can be interchanged without a complete disassembly of the gear head.