Patent ID: 8043007

Claim:
A carriage for mounting on a guide rail, the carriage comprising: a horizontally oriented back and two side limbs, extending vertically from the back, the back positioned between the two limbs; the back having an inner surface for facing a guide rail and an outer surface, opposite the inner surface for mounting a machine part thereon, the inner surface having two upper bearing surfaces for opposing corresponding bearing surfaces on the guide rail; each of the two limbs having a lower bearing surface for opposing corresponding lower bearing surfaces on the guide rail; each of the two upper bearing surfaces of the back having a pressure pocket for hydrostatic fluid; each lower bearing surface of each of the two limbs having a pressure pocket for hydrostatic fluid; the outer surface of the back having a clamping face for clamping the machine part, the clamping face being concavely arched to form a center recess such that the clamping face has edges which are parallel to a longitudinal center axis of the carriage and vertically above the center recess of the face, the center recess being parallel to the center axis of the carriage; each of the two limbs having a distal end which flex and pivot toward each other without contacting each other such that a horizontal distance between each distal end of the two limbs is smaller when the machine part is clamped to the clamping face than when the machine part is not clamped to the clamping face.