Parallelly-gripping chuck

A parallelly-gripping chuck comprising:

• a chuck body in which a cylindrical hole is opened;
• a piston which is slidably inserted in the cylindrical hole and is driven in the axial direction by air pressure;
• a piston rod which is attached to the piston and whose tip is projected from one end of the cylindrical hole;
• a pair of jaw components which are mounted at an end on a side from which the piston rod is projected of the chuck body via a guide block so as to be opened and closed;
• transforming means for transforming a movement of the piston rod to an opening/closing operation of the pair of jaw components;
• and the guide block for linearly guiding the opening/closing operation of the pair of jaw components in the direction which perpendicularly crosses the axial line of the rod,
• wherein the guide block integrally has:
• a block body of a substantially rectangular shape, having a first face on one side and a second face on the opposite side;
• a pair of guide walls which are formed integrally and symmetrically on the first face side of the block body, and extend in parallel with each other in the length direction of the block body, and between which the pair of jaw components are slidably fit;
• and at least one attaching wall which is integrally formed on the second face side of the block body and extends in the length direction of the block body, and the attaching wall is attached to the chuck body by being in contact with the outer face of an end of the chuck body and being fixed by attaching screws.