Guide posts that guide the elevating motion of a slide also serves as the
guide means for the elevating motion of a bolster. A bolster elevation
drive means consists of a hydraulic cylinder. The top of the hydraulic
cylinder is connected to the bottom of the bolster. For maintenance and
inspection of the dies, the bolster is lowered to open a space between the
upper die and the lower die. During operation of the press, the bolster is
supported by hydraulic pressure trapped in the hydraulic cylinder.
