摘要 |
According to the invention, a general purpose valve is provided to control the discharge of particulate material. An overlying plate with a first, through aperture, cooperates with an underlying plate having a solid surface and a second through aperture. The first aperture is in vertical alignment with the solid surface on the underlying plate. Structure is provided to vary the vertical spacing between the overlying and underlying plates to selectively commence, terminate, and vary the rate of flow of particulate material. |