WO2016185059A1 - Metering equipment - Google Patents

Abstract

Metering equipment, which comprises a tank (1) which in turn comprises a fixed liner (7) and a coupled piston (22) with the ability to move along the liner (7) and connecting the piston with the outlet of the tank and in that the piston (22) has an internal tube (222) that forms a sealed connection between the inlet and the outlet of the piston (22).

Description

 DOSAGE EQUIPMENT DESCRIPTION The present invention refers to a spray equipment capable of providing dosed volumes.

More specifically, the present invention refers to how to industrially transform a classic retained pressure lever sprayer (such as those described in Spanish Patent Documents ES1012723U, ES2024847A6, ES1077726U), into a back equipment ( or type "backpack") capable of providing dosed volumes.

It is customary, in the agricultural sector, to use backpack-type equipment to spray insecticides, fungicides, herbicides, even foliar fertilizers, for which it is convenient to have a device with pressure accumulation capacity. Document ES1077726U discloses such a spray group. However, there are certain applications in which what is sought is to provide dosed volumes. The general dosing equipment has a very different design from the backpack type equipment. In the face of manufacturing economics, it would be convenient to have dosing equipment that shared characteristics with dosing equipment of known type. Likewise, this type of design would eventually allow the transformation of existing sprayers.

There are several models of equipment on the market dosers derived from known spray equipment geometries. However, such models, such as the one disclosed in the Brazilian Utility Model document BRMU8500919U, referring to a costal type sprayer transformer device in liquid dispenser, are not entirely satisfactory.

According to the studies carried out by the applicant, to convert a retained pressure backpack type device into a dosing backpack type equipment, it is convenient to modify three functions of a retained pressure backpack type equipment. In the first place and as a main aspect, the pressure accumulating capacity of the chamber of backpack type sprayers has to be eliminated. If the pressure is involved in the dosing process, the volume that goes out through the lance of the dispenser varies depending on that pressure, preventing precise dosing. Therefore, it is most effective not to build up pressure and evacuate the liquid directly as it enters the pump chamber of the backpack type sprayer. Suction in a back sprayer is carried out through a cylinder with a suction valve and a chamber with a discharge valve, so eliminating the accumulative capacity of the chamber, the volume that comes out of the lance will be equal to the volume sucked in the cylinder Consequently, since the evacuated volume is proportional to the suction path, a second change necessary for the regulation and control of the dose consists in limiting the chamber travel. Whenever the route is perform from top to bottom, or through the entire run, you get pre-determined dosing volumes. Thus, the present invention provides that, by varying the limit travel positions, it is achieved that the doses can be adjusted to the amount desired by the user.

Backpack type sprayers, as they do not have a handle, require a non-drip valve at the tip of the lance to prevent dripping that unloads the backpack due to the effect of communicating vessels. The drip valve prevents the suction of air from the outside through the tube, since the only possible suction is in the direction of the backpack towards the chamber.

In order to eliminate the pressure accumulation capacity, currently known solutions involve removing the suction tube from a pressure chamber such as that described in Spanish patent document ES1012723U. In backpack type sprayers, which have a retained pressure chamber, the function of the suction tube is to force the liquid from the chamber to be sucked from the bottom and thus prevent the air that is inside the chamber and that It is the one that allows to pressurize the liquid out through the outlet hose. Normally in the chambers of the pressure-retained backpacks, this suction tube is an independent tube that is inserted from the chamber outlet joint (hose chamber joint) to the bottom of the chamber. By removing this tube, the chamber becomes a single volume, in which the air due to its lower weight than the water tends to occupy the upper part of it and is evacuated in the first place, which allows the chamber to lose the air retention capacity and is completely filled with liquid. This phenomenon is called "priming."

In this way, once the air in the chamber has been evacuated (priming), the suction becomes proportional to the chamber travel. However, there is still a very important problem of internal waste when the tank reaches the end of its volume. When the liquid in the tank comes to an end, the cylinder no longer sucks water from the tank, but instead sucks air. This air enters the chamber. Since the air weighs less than the liquid, it comes out directly, so that the liquid inside the chamber cannot be evacuated. In this type of cameras the volume usually ranges between 500 cm and 1500 cm ³ , so the volume that is not evacuated is important.

More particularly, the present invention consists of a dispenser comprising a reservoir which in turn comprises a fixed sleeve and a conjugate piston with movement capacity along the jacket and connected the piston with the outlet of the reservoir, and by which The piston has an internal conduit that tightly communicates the inlet with the piston outlet, lacking pressure retaining elements at the inlet to the piston. The invention provides that the connection lacks pressure retaining elements at the piston inlet. However, the absence of non-return elements simplifies the construction.

Preferably, this duct within the chamber has a volume less than the volume of the jacket or cylinder. More preferably, said sealed communication between the input and the output is carried out by means of a hollow shaft with its relevant joints. Even more preferably, said conduit is coaxial to the piston, and has the same mass as the valve nut that tightens the suction seal.

Preferably said internal duct comprises a cylindrical part attached to the piston.

Preferably said internal duct has the same mass as the cylindrical part. Preferably, it has a lever arm part with a stop, said stop being disposed in the path of the main operating lever, thus limiting the travel of the lever and consequently of the piston.

More preferably, the position of the stop is adjustable along the axis of the lever arm for example with a groove in a sheet welded to the lever arm and in the same direction of the axis of the lever arm.

Even more preferably, said stop is made with a screw that fits into positions made along said groove and a locking means, for example with a cylindrical nut.

In a particularly preferred embodiment, said sheet has the aforementioned positions presenting said positions inversely to that of the screw in order to accurately identify and fix, without the risk of involuntary variation, intermediate positions.

More preferably, the cylindrical nut has a through hole in the radial direction at the opposite end of the thread so that a screwdriver or shaft can be introduced therein and thus increase the tightening torque.

More preferably, the sheet has a graduated scale with dose equivalents.

For your better understanding, some drawings of an embodiment of the dosing equipment object of the present invention are attached by way of explanatory but not limiting example.

Figure 1 shows the perspective view of a dosing device according to the present invention. Figure 2 shows another perspective view of the dosing equipment of Figure 1 and a dosing lance.

Figure 3 shows a sectional view of the equipment of Figure 1, along the middle plane showing the interior components.

Figure 4 shows an enlarged detail of Figure 3.

Figure 5 shows an enlarged detail of the upper part of the chamber of the embodiment shown in the previous figures.

Figure 6 shows a perspective view of a body cylindrical used to transform a backpack type spray equipment design to a dosing device.

Figures 7 and 8 show enlarged details, in perspective, of the mechanism for regulating the equipment according to the present invention shown in the previous figures.

Figure 9 shows a perspective view in which the stop system for the lever travel is shown schematically.

Figure 10 schematically shows a top plan view of the screw and plate used to fix the travel stop.

Figure 11 shows a perspective view of the plate and the screw.

Figure 12 shows another perspective view of the screw.

Figure 13 shows a perspective view of the part that forms the base of the screw and comprising the projections that subsequently fit into the recesses of the plate.

Figure 14 shows a sectional view of Figure 2 in which the interior elements of a non-return valve are seen.

Figures 1 to 14 show an embodiment of geometry dosing equipment derived from a backpack type spray equipment comprising a tank -1- Attachable to the back as a backpack that has a chamber -22- inside that corresponds to the pressure chamber of the retained pressure backpack sprayers (see figure 3). The chamber -22- constitutes a piston that moves along the jacket -7- to drive the liquid out of the equipment.

The example shown also presents a suction valve -8- typical of retained pressure sprayers (see figure 4). Unlike the pressure retained spray equipment, it does not, however, have any discharge valve. Therefore, the volume dosed by the dosing device corresponds to the volume of the chamber -22- associated with the suction path -230-, which corresponds to the top-to-bottom path of the chamber -22- (see figure 3). As shown in Figure 4, the typical flow valve of the pressure retained spray equipment has been replaced by a cylindrical body -223- which is attached to the chamber -22- preferably by means of a thread -262-. For this purpose, the threading with which the discharge valve is attached to the chamber can be used in the retained pressure backpack type sprayers. In addition, the cylindrical body -223- seals tightly with the suction tube -222-. For this, the cylindrical body -223- has a diameter somewhat smaller than that of said suction tube -222-, being inserted inside it. An O-ring -252- ensures the tightness between the two. The tightness ensures the elimination of the pressurized effect of the pressure retained equipment and with it the accumulative capacity of the chamber in these equipment. The use of the suction tube -222- in combination with the cylindrical body -223- also causes it to be reduced dramatically the volume downstream from the suction point to the nozzle, that is, the sum of volumes of the suction tube -222- and the internal tube of the cylindrical body -223- is smaller than that of the cylinder -224-. When this relation of volumes is fulfilled, it is ensured that the final waste is non-existent and that the entire volume of the deposit can be sucked and evacuated. In particular, thanks to this relation of volumes, it is not necessary to implement additional non-return systems to the drip nozzle -301- to start the suction, that is, to achieve the priming of the pump constituted by the cylinder -224- and the piston -22 -. This simplifies the machine and makes it more robust in terms of obstructions and guarantees uniform dosing.

A main novelty of the present invention is that using a traditional architecture of a piston sprayer, such as the one set out in Spanish patent document ES1077726U, the discharge valve is replaced by a preferably threaded cylindrical body -223- which In addition to tightening the suction joint -233-, it connects tightly with the suction tube -222-. In this way, the pressurizing function is canceled and the downstream volume from the suction point to the nozzle is drastically reduced (suction tube volume -222- + cylindrical body volume -223- <cylinder volume -224-). With this reduction of the volume of the chamber the final residue is non-existent, since the entire volume of the tank can be sucked and evacuated.

Reducing the volume of the chamber by direct output (cylindrical body -223- + suction tube -222-) also facilitates priming of the chamber. As the Pumping volume (cylinder volume -224-) of a sprayer is normally less than 150 cm (preferably between 25 and 100 cm), if the chamber volume is greater than the suction capacity (cylinder volume -224-), This does not exert enough vacuum to suck the liquid from the tank, so both a non-return closure in the chamber (discharge valve) are necessary to guarantee suction and priming. In this case, the chamber volume -223 - + - 222- is reduced below the suction volume -224-. Therefore, it is not necessary to implement additional non-return systems to the drip nozzle to start suction (priming). This simplifies the machine and makes it more robust in terms of obstructions and guarantees uniform dosing. Alternatively, anti-return systems can also be provided.

As for the limitation of the camera travel -230-, in the market there are different alternatives that range from directly limiting the camera travel to limiting the travel of the lever, but the embodiment shown in Figures 9 to 13 presents the advantage of not compromising the tightness of the deposit. The main advantage of this alternative is that the lever stops are made between the parts of the lever and not between the lever and the tank, so that the stops are very robust and the tank does not have to be drilled.

Figures 7 and 8 show a possible solution to limit camera travel -230-. An upper bumper -225- is arranged to travel the lever in the part lever arm -226- so that this stop -225- meets the main drive lever -227- in its travel, thus limiting the travel of the lever arm -226- and consequently the travel of the camera / piston -230-. The lower stop is made between a rib -231- in the upper part of the chamber and the guide nut -232- (see figure 5).

The position of the upper stop -225- is adjustable along a groove in a sheet -228- welded to the lever arm -226- and in the same direction as the axis of the lever arm. This stop, for example, is made with a screw (type DIN603) -229- with a shape that fits in reverse positions made along this groove and is locked with a -225- cylindrical nut. The sheet -228- has recesses inversely to that of the projections of the screw head -229- in order to identify and fix precisely the predetermined positions without risk of involuntary variation. The sheet -228- has an engraved scale -500- in which the positions with their respective doses can be identified.

Figures 9 to 13 show another possible embodiment of the stop -225-, which is slightly different from the embodiment shown in the previous figures. Specifically, the design of the butt head -225- is different, being improved for a better and safer system behavior. The same or similar elements to the previous embodiments have been designated with identical numerals and will not be explained again in detail.

In the embodiment of figures 9 to 13 the stop -225- is formed by a main body -2259- which has a internal thread -2252- in which a screw -2255- is threaded. The screw -2259- has an elongated head -2254-. The elongated head has dimensions such that it is capable of traversing the slot -2281- of the sheet -228- only in a radial position, such that the stop -225- can only be removed from the sheet -228- in said position radial. The main body -2259- has two projections in the form of battlements -2256- whose shape is conjugated with that of the slot recesses -2281-. In addition, the battlements -2256- are angularly offset with respect to the elongated head -2254-.

In this way, the accidental exit of the stop -225- is prevented when it rests in one of the positions defined in the sheet -228-. The battlements -2256- can have two heights, in order to further reduce the movements of the stop -225-. As a whole, the stop -225- ends with a knurled area -2251- to favor the activation of the stop.

The unloading is carried out with a lance without handle and with a non-return or anti-drip valve as shown in figure 2. Figure 14 shows the inside of a non-return valve -301- comprising a ball -302- shutter and a spring -303- that drives said ball -302-.

While the invention has been described with respect to examples of preferred embodiments, these should not be construed as limiting the invention, which will be defined by the broader interpretation of the following claims.

Claims

1. Dosing equipment, characterized in that it comprises a reservoir which in turn comprises a fixed sleeve and a conjugate piston capable of moving along the sleeve and connecting the piston with the tank outlet and because the piston has an internal duct which communicates tightly the inlet with the piston outlet. 2. Equipment according to claim 1, characterized in that said internal duct has a volume less than the volume of the jacket. 3. Equipment according to claim 1 or 2, characterized in that said internal duct that tightly communicates the inlet with the piston outlet comprises a hollow shaft located inside the piston. 4. Equipment according to claim 3, characterized in that said hollow shaft is coaxial to the piston. 5. Equipment according to any one of claims 1 to 4, characterized in that said internal duct comprises a cylindrical part attached to the piston. 6. Equipment according to any one of claims 1 to 5, characterized in that said internal duct has the same mass as the cylindrical part. 7. Equipment, according to any of the preceding claims, characterized in that it has a lever arm part with a stop having said stop in the travel of a main drive lever thus limiting the travel of the lever and consequently the travel of said piston. 8. Equipment according to claim 7, characterized in that the position of the stop is adjustable along the axis of the lever arm with a groove in a plate welded to the lever arm and in the same direction as the axis of the lever arm. Equipment according to claim 8, characterized in that said stop is made with a screw that fits in positions made along said groove and a locking means, for example with a cylindrical nut. 10. Equipment according to claim 9, characterized in that said positions are inverse inverse to that of the projections of the screw in order to identify and precisely fix intermediate positions without risk of involuntary variation. 11. Equipment according to any of claims 9 to 10, characterized in that the locking means has a through hole in the radial direction at the opposite end to the thread in order to be able to insert a screwdriver or shaft therein and thereby increase the tightening torque. 12. Equipment according to any of claims 8 to 11, characterized in that the sheet has a graduated scale with the dose equivalences. 13. Equipment according to any of claims 9 to 12, characterized in that the groove of the sheet has an area of enlarged width to introduce said screw.