Patent ID: 7140555

Claim:
A hydraulic circuit for a line marker having a spray nozzle for spraying a marking liquid downwardly to mark a line on a horizontal surface, which comprises: (a) a reservoir for holding a supply of the marking liquid, wherein the reservoir further includes a drain outlet for draining liquid from the tank; (b) a pump for pumping the marking liquid from the reservoir and for supplying the marking liquid to the spray nozzle; (c) a selectively operable control valve which permits spray of the marking liquid from the spray nozzle when the control valve is in a first state and which prevents spray of the marking liquid from the spray nozzle when the control valve is in a second state; and (d) a recirculation path for recirculating at least a portion of the marking liquid being pumped by the pump back to the reservoir when the control valve for the spray nozzle is in the second state, wherein the recirculation path includes: (i) a reservoir inlet for receiving the recirculated portion of the marking liquid; and (ii) a reservoir hose operatively connected to the reservoir inlet with the reservoir hose being disposed inside the reservoir and extending around at least a portion of the reservoir for conducting the recirculated portion of the marking liquid into and at least partially through the reservoir, and wherein the reservoir hose is long enough to be selectively and manually redirected to pass into the drain outlet such that any liquid entering the reservoir through the reservoir hose is immediately dumped out of the reservoir through the drain outlet.