The invention relates to a device and method for applying a spraying means using a portable spraying device.

System to prevent leaks of liquids in a manual sprayer—insecticides, herbicides, fungicides—comprised by a large storing tank in which a recipient is installed under pressure. A pumping assembly, which is manually activated, is connected to the inferior part of the container under pressure and to the lower part of the tank. The pumping assembly is comprised of an alternative piston to extract the liquid from the storing tank and to pressurize it inside the container under pressure. The pressurized liquid is applied using a hose and a regulating valve attached to the container under pressure. The pumping ensemble is comprised as well by a double-walled piston and a barrier against leaks of the piston, formed by a flexible sealing accordion with four lobes or waves that avoid grazing the cylinder and that prevent leaking from taking place between the superior side of the piston and the inferior side of the piston chamber, thus blocking the exit of liquid and forcing it to stay at the collection chamber until it is once again emptied thanks to the descending movement of the piston. The liquid is therefore taken back from the collection chamber to the storing tank by means of a returning hose, of an internal duct and of a siphon that unloads above the liquid level.

An internal pump backpack sprayer system includes a first tank, a second tank and a pump unit. The first tank includes a tank housing for holding a fluid. The second tank is received within the first tank and receives a pressurized fluid. The pump unit has a cylinder housing with first and second inlets and first and second outlets, a piston within a cylinder and a pressure discharge assembly. When the piston moves in an up-stroke, fluid is drawn from the first tank through the first inlet while all or some pressurized fluid is discharged through the pressure discharge assembly with a remainder being discharged to the second tank through the second outlet. When the piston moves in a down-stroke, fluid is drawn from the first tank through the second inlet while pressurized fluid is discharged to the second tank through the first outlet.

System to prevent leaks of liquids in a manual sprayerinsecticides, herbicides, fungicidescomprised by a large storing tank in which a recipient is installed under pressure. A pumping assembly, which is manually activated, is connected to the inferior part of the container under pressure and to the lower part of the tank. The pumping assembly is comprised of an alternative piston to extract the liquid from the storing tank and to pressurize it inside the container under pressure. The pressurized liquid is applied using a hose and a regulating valve attached to the container under pressure. The pumping ensemble is comprised as well by a double-walled piston and a barrier against leaks of the piston, formed by a flexible sealing accordion with four lobes or waves that avoid grazing the cylinder and that prevent leaking from taking place between the superior side of the piston and the inferior side of the piston chamber, thus blocking the exit of liquid and forcing it to stay at the collection chamber until it is once again emptied thanks to the descending movement of the piston. The liquid is therefore taken back from the collection chamber to the storing tank by means of a returning hose, of an internal duct and of a siphon that unloads above the liquid level.

A dual chamber backpack sprayer system includes first, second and third tanks, and a pump unit. The first tank includes a first tank housing defining an open internal volume configured to hold a diluent therein. The second tank is dimensioned to be received within the internal volume of the first tank and is configured to hold a pressurized fluid therein. The third tank includes a third tank housing configured to hold a liquid concentrate therein. The pump unit is fluidly coupled to the first tank, the second tank and the third tank. The pump unit is configured to receive the diluent from the first tank and the liquid concentrate from the third tank to produce a mixed fluid. The mixed fluid is delivered to the second tank as the pressurized fluid.

An internal pump backpack sprayer system includes a first tank, a second tank and a pump unit. The first tank includes a tank housing for holding a fluid. The second tank is received within the first tank and receives a pressurized fluid. The pump unit has a cylinder housing with first and second inlets and first and second outlets, a piston within a cylinder and a pressure discharge assembly. When the piston moves in an up-stroke, fluid is drawn from the first tank through the first inlet while all or some pressurized fluid is discharged through the pressure discharge assembly with a remainder being discharged to the second tank through the second outlet. When the piston moves in a down-stroke, fluid is drawn from the first tank through the second inlet while pressurized fluid is discharged to the second tank through the first outlet.

A dual chamber backpack sprayer system includes first, second and third tanks, and a pump unit. The first tank includes a first tank housing defining an open internal volume configured to hold a diluent therein. The second tank is dimensioned to be received within the internal volume of the first tank and is configured to hold a pressurized fluid therein. The third tank includes a third tank housing configured to hold a liquid concentrate therein. The pump unit is fluidly coupled to the first tank, the second tank and the third tank. The pump unit is configured to receive the diluent from the first tank and the liquid concentrate from the third tank to produce a mixed fluid. The mixed fluid is delivered to the second tank as the pressurized fluid.

A backpack sprayer system includes a mounting bracket having a battery receiving fixture. A first tank is mounted to the mounting bracket and holds a diluent. A second tank is mounted to the mounting bracket and holds a liquid concentrate. The second tank is selectively, individually removable from the mounting bracket. A mixing manifold is mounted to the mounting bracket and has a first inlet fitting to receive a fixed amount of diluent and a second inlet to receive an adjustable amount of liquid concentrate. The diluent and concentrate are combined to form a mixed solution with the mixing manifold including a mixed solution outlet. A positive displacement pump is mounted to the mounting bracket and has a suction port coupled to the mixed solution outlet and a pressure port coupled with a spray device. A control unit is mounted on the mounting bracket and receives power from the battery.

An internal pump backpack sprayer system includes first and second tanks and a double action pump unit. The first tank defines an open volume to hold a fluid. The second tank is received within the first tank and receives a pressurized fluid therein. The double action pump includes a cylinder and piston assembly having a cylinder housing with first and second inlets and first and second outlets. A piston is located and moveable within a cylinder. When the piston moves in an up-stroke, a first portion of the fluid is drawn from the first tank through the first inlet while the pressurized fluid is discharged to the second tank through the second outlet. When the piston moves in a down-stroke, a second portion of the fluid is drawn from the first tank through the second inlet while the pressurized fluid is discharged to the second tank through the first outlet.

A battery operated backpack sprayer is provided where the battery is releasably mounted under a housing attached to the tank of the sprayer. At the bottom of the housing is a receptacle for the battery and from which the battery can be released for recharging or replacement.