Apparatus for dispensing agricultural chemicals.

摘要

A manual applicator, for dispensing liquid agricultural chemicals, comprises a reservoir (11) for the liquid chemical and a hand-held dispensing apparatus (15). The reservoir (11) is provided with a non-return valve adapted to allow air to flow into the reservoir (11) when the head space in the reservoir falls below a predetermined pressure below atmosphere. In one embodiment an annular valve closure member (22) is mounted on a valve body (21) within the reservoir and one end (31) of the valve body (21) extends through the reservoir wall (W). The plane of the peripheral edge regions (26) of the diaphragm (22) is spaced from the plane of the central part (23) of said diaphragm (22) and is in pressure contact with an internal surface (W1) of the reservoir wall (W). That face of the diaphragm (22) within the peripheral edge region (26) is open to atmosphere via ducts (35 and 36) in the valve body (21).