Portable machine tool

A machine tool comprising:

• a support structure having first and second opposite ends spaced apart along an axis,
• a drive assembly mounted on the support structure at said first end thereof, said drive assembly comprising at least one drive motor and an output drive shaft coupled drivingly to said drive motor,
• a machining head mounted on the support structure at the second end thereof,
• a tool support member mounted on the machining head and movable relative thereto,
• transmission means coupling said output drive shaft to the tool support member to effect movement of the tool support member, said transmission means including a transmission shaft extending parallel to said axis over at least a substantial part of the distance from the first ends of the support structure to the second end thereof, and
• feed means for effecting synchronous movement of the drive assembly and the machining head relative to the support structure in directions perpendicular to said axis, and wherein the feed means comprise a feed shaft extending parallel to said axis and coupled drivingly at opposite respective ends to the drive assembly and the machining head in a manner such that rotation of the feed shaft causes synchronous movement of the drive assembly and the machining head relative to the support structure with equal velocities.

A machine tool comprising:

• a support structure having first and second opposite ends spaced apart along an axis,
• a drive assembly mounted on the support structure at said first end thereof,
• a machining head mounted on the support structure at the second end thereof, and
• a feed shaft coupled drivingly at opposite respective ends to the drive assembly and the machining head in a manner such that rotation of the feed shaft relative to the support structure causes synchronous movement of the drive assembly and the machining head relative to the support structure in directions perpendicular to said axis.

A machine tool comprising:

• a support structure having first and second opposite ends spaced apart along an axis,
• a drive assembly mounted on the support structure at said first end thereof, said drive assembly comprising at least one drive motor, first and second output drive shafts coupled drivingly to said drive motor, and means for adjusting the relative angular velocities of rotation of said output drive shafts,
• a machining head mounted on the support structure at the second end thereof,
• a tool support member mounted on the machining head and movable relative thereto in first and second degrees of freedom, the first and second output drive shafts being coupled to the tool support member to effect movement of the tool support member in the first and second degrees of freedom, and
• means coupling the drive assembly and the machining head for synchronous movement relative to the support structure in directions perpendicular to said axis.

A tool for machining a valve defining a valve chamber having a fluid inlet and a fluid outlet and an access passage for giving access to the valve chamber, the tool comprising:

• a support structure having first and second opposite ends spaced apart along an axis, the support structure being attached to the valve so that it extends within the access passage with the first end of the support structure outside the valve chamber and the second end inside the valve chamber,
• a drive assembly mounted on the support structure at said first end thereof,
• a machining head mounted on the support structure at the second end thereof, and
• means coupling the drive assembly and the machining head for synchronous movement relative to the support structure in directions perpendicular to said axis, whereby the machining head can be moved within the valve chamber while remaining stationary relative to the drive assembly.