| 摘要 |
A concrete pipe making machine having a packerhead vibrating core and a control for automatically controlling the movement of the packerhead and core relative to each other as the packerhead and core move up and down within a mold to form a concrete pipe. The control has valve units operable to restrict the flow of hydraulic fluid supplied to the hydraulic control cylinders which control the movements of the packerhead and core.
|
