Implement for contact application of liquid herbicides to crops

Claim 1

A farm implement for contact application of a liquid to growing plants, comprising: frame means adapted to be moved across a field of growing plants on which a liquid is to be applied; an elongated wiper bar supported by the frame means and extending transversely to the direction of movement thereof, the wiper bar comprising a plurality of longitudinally-extending sections, each of the sections comprising a rigid support member and liquid-absorbent material surrounding the support member; a tank for the liquid mounted on the frame means above the wiper bar at a first elevation above the wiper bar; a feed line extending downwardly from the tank for gravity feeding liquid to the wiper bar; a plurality of drip valves connected in parallel to the feed line below the tank, each of the drip valves being at a second elevation which is less than the first elevation above the wiper bar, each of the drip valves being associated with a respective section of the wiper bar; and a plurality of closed distribution conduit means, one of the plurality of conduit means connecting each of the drip valves with the interior of its respective section of the wiper bar for individually supplying liquid to each said section and to the material surrounding the support member thereof, each of the conduits means including sighting means for viewing the level of liquid in the conduit means; the drip valves being adjustable and the distribution conduit means being sized to establish an independent visible head of liquid in each of the conduit means during flow of liquid from the tank, thereby to obtain a constant flow of liquid to each of the sections of the wiper bar regardless of the relative elevation of the sections with respect to each other.

Claim 6

A method of distributing liquid from a tank to the interior of an elongated liquid-applying agricultural wiper bar, the bar comprising a plurality of longitudinally-extending sections, each of the sections comprising a hollow rigid support member and liquid-absorbent material surrounding the support member, the tank being at a first elevation above the wiper bar, the method comprising: dividing a primary flow of liquid from the tank into a plurality of secondary flows corresponding to the number of sections of the wiper bar; and individually metering the secondary flows to each of the sections of the wiper bar through conduit means including liquid sighting means from a second elevation which is less than the first elevation above the wiper bar, said metering of said secondary flows being at a rate sufficiently restricted to cause a visible independent head of liquid to develop in the sighting means above each of the sections, thereby to obtain a constant flow of liquid to each of the sections of the wiper bar regardless of the relative elevation of the sections with respect to each other.

Claim 7

A method of distributing liquid from a tank to the interior of an elongated liquid-applying agricultural wiper bar, the bar comprising a plurality of longitudinally-extending sections, each of the sections comprising a hollow rigid support member and liquid-absorbent material surrounding the support member, the tank being at a first elevation above the wiper bar, the method comprising: dividing a primary flow of liquid from the tank into a plurality of secondary flows corresponding to the number of sections of the wiper bar; and individually metering the secondary flows to each of the sections of the wiper bar through conduit means including liquid sighting means from a second elevation which is less than the first elevation above the wiper bar, said metering of said secondary flows being at a rate sufficiently restricted to cause a visible independent head of liquid to develop in the sighting means above each of the sections, thereby to obtain a constant flow of liquid to each of the sections of the wiper bar regardless of the relative elevation of the sections with respect to each other.