| 摘要 |
A support for positioning a milker unit beneath a cow has a shaft which is vertically movably mounted on a base. An arm on the shaft supports a milker unit beneath a cow. Air pressure is applied to the shaft to hold the shaft and arm at a desired vertical position. A control automatically adjusts the vertical position of the support so that when the milker unit is attached to a cow's teats the weight of the milker unit is applied solely to the cow's teats. The control includes a pair of valves each connected to a supply of air under pressure. A first of the valves has an open position in which the amount of pressure applied to the support decreases and the support is permitted to lower. A second of the valves has an open position in which air from the supply moves the first valve from a normally closed position to the open position thereof. The control has a lever mounted on the arm for moving the second valve to the open position thereof when the milker unit applies force to the lever.
|
