A tool holder is provided for holding one of a tool and workpiece. The tool holder is configured for mounting to a driving member of a machining device. The tool holder includes a tool holder first end including a coupler for coupling the tool holder to the driving member of the machining device. A tool holder second end includes a clamp for releasably holding one of the tool and workpiece. A force sensor is disposed between the clamp and the coupler for sensing force exerted on the one of the tool and workpiece held by the clamp. A linear actuator is disposed between the clamp and the force sensor for linearly moving the one of the tool and workpiece.

A tool feeding mechanism for a tool driving device includes a cylinder mechanism, a positioning mechanism, and a holding mechanism. The cylinder mechanism moves a tool rotation driving device to hold and rotate a tool, in a tool axis direction on an exterior of a cylinder tube using power of a piston. The positioning mechanism is connected to the cylinder tube side of the cylinder mechanism either directly or indirectly in order to position the cylinder mechanism relative to a workpiece. The holding mechanism holds the tool rotation driving device such that the power of the piston in the cylinder mechanism is transmitted to the tool rotation driving device.

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.

An air control device includes an air suction port, air discharge ports, and an air control system. The air suction port takes in air. The air discharge ports discharge the taken-in air. The air control system discharges the air through the air discharge ports alternately for respective preset times. An air control method includes: taking in air; and discharging the air alternately through air discharge ports for respective preset times.

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.