Abstract: A pinch valve includes a body with a passageway extending therethrough, a flexible sleeve mounted within the body and surrounding the passageway, and a cavity between the sleeve and the body. An inlet opening provides control fluid flow into the cavity, while an outlet opening allows for fluid exhaust from the cavity. The diameters of the inlet and outlet openings are fixed, with the inlet diameter being smaller than the outlet diameter. A two-way control valve opens and closes the outlet opening, and thereby controls opening and closing of the pinch valve.

Abstract: The foam marking device of the present invention includes a solution tank with a tube extending upwardly therein. An air line extends from an air pump and into the tank so as to provide air into the tube. The air passes through a porous element so as to create air bubbles. The tube includes an elongated slot that allows foam solution within the tank to enter the tube. The air bubbles generate foam within the upper end of the tube. The foam passes through a homogenizer at the upper end of the tube and then into a foam line for discharge onto the ground. The slot serves dual functions, by allowing solution in the tank to enter the tube and by allowing foam within the tube to enter the tank when the pressure in the foam discharge line exceeds the pressure within the tube.

Abstract: A foam marking system is provided with separate tanks for water and foam concentrate. A water pump and a concentrate pump deliver water and concentrate from the respective tanks to a mixing chamber at a pre-selected ratio. The water pump is controlled by a master control, while the concentrate pump is controlled by a slave control depending from the master control. The master control generates and output signal which is sent to both the water pump and the slave control, such that the slave control and concentrate pump operate as a function of the master control and water pump, so that the selected mix ratio can be maintained, regardless of the output level of the foam from the system. A foam generation chamber connected to the mixing chamber and to an air source generates foam when the foam solution is mixed with air.

Abstract: The foam dispensing apparatus is mountable on a self-propelled or manually propelled vehicle such as a planting, fertilizing and spraying machine or like surface working vehicles. A peristaltic or squeeze type pump has an inlet section for receiving air and a foam agent solution which are mixed and successively moved through the pump for discharge in a foam form from the pump outlet section. A discharge nozzle connected to the outlet section is arranged to apply the foam material on the ground surface at a position adjacent to one side of the vehicle. The pump is driven at a rate in response to the ground speed of the vehicle over the ground surface and the air and foam agent solution mixture may be proportionally varied to maintain visual observance of the foam on the ground surface for varying time periods.