Atomizing Device

Abstract

An atomizing device in the form of a gun provided with a barrel constituted of two coaxial tubes, the outer tube of which communicates with a pipe for delivering water under pressure and the inner tube of which communicates with a tank containing the concentrated liquid product to be atomized and which is fixed to the gun. A venturi member in the form of a bobbin is mounted at the outlet end of the outer tube and it comprises two spaced annular flanges whose diameters are substantially equal to the inside diameter of the outer tube of the barrel, and an intermediate hollow part of reduced diameter. The venturi member has a first hole passing axially through the center of the upstream flange into an inner chamber of the intermediate hollow part, a second hole passing axially through the center of the downstream flange and into the inner chamber, and a third hole passing radially through the wall of the intermediate hollow part. A tubular coupling is formed integrally with the upstream flange and eccentrically in relation to the axis of the venturi and its inner bore opens into the annular space between the flanges, the tubular coupling being connected in fluid-tight manner to the end of the inner tube of the barrel.

Description

The present invention relates to an atomizing device, adapted particularly for atomizing an insecticide mixture on to garden plants.

The atomizing device of the invention is characterized in that it is in the form of a gun provided with a barrel made up of two coaxial tubes, the outer tube communicating with a pipe for delivering pressurized water, and the inner tube communicating with a tank containing the concentrated liquid product which is to be atomized and which is suitable for the device, said outer tube receiving at its outlet end a venturi comprising a first and a second passage connected on the upstream side to the outer and inner tubes respectively of the barrel, and, on the downstream side, to a suction chamber which extends to form a common channel through which jets of pressurized water and liquid which is to be atomized can flow.

A device of this kind functions in a very simple manner: as soon as the trigger is squeezed, the water under pressure enters into the appliance where it flows into the space between the two coaxial tubes in the barrel and then crosses the venturi by way of said first passage. In accordance with the well known principle of the venturi, the jet of pressurized water causes a vacuum to form in the suction chamber which causes the liquid which is to be atomized and which is contained in the tank, to be sucked through the inner tube of the barrel and said second passage. The two jets of water and liquid which is to be atomized become mixed together in said common channel and are atomized into a homogeneous spray.

According to one embodiment of the invention, the venturi is in the form of a bobbin comprising two annular flanges the diameter of which is substantially equal to the inside diameter of the outer tube of the barrel, and the edges of which are provided with grooves for receiving sealing joints, and comprising an intermediate hollow part of reduced diameter, a first central hole which passes through the center of the upstream flange and which opens out through a tubular portion inside the chamber formed inside said intermediate hollow part, a second ejection hole passing through the center of the downstream flange in such a way as to form a communication between said chamber and the atmosphere, a third hole made in the wall of the intermediate part and forming a communication between the annular space between the flanges and said chamber, a fourth hole made in the wall of the upstream flange, eccentrically in relation to the axis of the venturi, and finally a tubular coupling formed integrally with the venturi and extending said fourth hole on the upstream side, said tubular coupling being connected in a liquid-tight manner to the end of the inner tube of the barrel.

One particular embodiment of the invention is described in detail, in a non-limiting way, with reference to the attached drawings, in which

FIG. 1 is a view in longitudinal section of an atomizing device according to the invention;

FIG. 2 is a view from above of the device shown in FIG. 1;

FIG. 3 is an elevation view of a venturi used in the device of the invention; and

FIG. 4 is a view in axial section of the venturi shown in FIG. 3.

With reference to FIG. 1, the atomizing device has the general shape of a gun. It comprises a gripping member 1 in the form of a curved handle in which a pipe 2 is fitted, said pipe ending, outside the handle, in a threaded connection 3 which can be joined with a water pipe, not shown, and a barrel 4 made up of two coaxial tubes. The outer tube 5 of the barrel is connected to the pipe 2 by means of a valve 6 loaded by a spring 7 and operated by a trigger 8 which is pivoted at 9 at the end of the valve 6. The inner tube 10 of the barrel is prolonged by a suction portion 11 immersed in a concentrated liquid 12 which is to be atomized and which is contained in a tank 13. A part made of plastic material is mounted on the body of the barrel, said part comprising a threaded end 14 in which the tank 13 is screwed and a suspension member 15 having therein a hole 16 by which the appliance can be hung when it is not being used.

According to the invention, a revolving handle 17 is mounted on the barrel 4 of the appliance. As FIG. 2 shows, the handle can be moved, during use, into a horizontal position either towards the right or towards the left. Because of this feature the applicance can be operated by both right-handed and left-handed persons. Furthermore, it can happen that the same person using the device can move the handle first to the left and then to the right. The operator must in fact have all the freedom of movement to enable him to turn or to stride over the delivery pipe.

A venturi 18 is mounted on the end of the barrel 4, said venturi being held in position inside a threaded end portion 19. A conical member 20 in the form of a bell is screwed onto said threaded end 19, said member 20 being fitted with a diffuser 21 which can be adjusted in different directions.

FIGS. 3 and 4 show on a larger scale the venturi 18. This is made up of two parts 22, 23, preferably made of plastic material.

The part 22 has a general shape similar to that of a bobbin for wire. It comprises two annular flanges 24, 25 which are joined by means of an intermediate hollow portion 26 of reduced diameter. The flanges have a diameter which is substantially equal to the inside diameter of the end portion 19 in which the venturi is fitted and are provided, respectively, on their edges with a groove 27 and a shoulder 28 each of which receive a sealing joint 29, 30 (see FIG. 1) ensuring that the end of the barrel is sealed.

A tubular coupling 31 which is eccentric in relation to the axis of the venturi projects on the upstream flange 24. The bore 32 of this coupling passes through the flange 24 and opens out into the annular space 33 defined between the flanges 24, 25, the intermediate portion 26 and the inside wall of the end 19. As FIG. 1 shows, the tubular coupling is connected to the inside tube 10 of the barrel by means of a flexible pipe 34. The part 22 comprises, in addition, a central hole 35 which passes through the center of the upstream flange 24 and which opens out through a tubular part 36 inside the bore 37 of the intermediate portion 26. The wall of said portion 26 is pierced with a hole, 38, at the level of the end of the tubular part 36, said hole 38 forming a communication passage between the annular space 33 and the bore 37.

The part 23 of the venturi comprises a projection 39, located in its center, said projection engaging through simple finger pressure inside the bore 37 of the part 22, and a flange 40 which together with the flange 25 forms the groove 28 in which the joint 30 is located. The part 23 is also pierced with a central bore 41 which forms a communication passage between the inner space 37 of the part 22 and the atmosphere.

The venturi can of course be made from one integral part.

The device which has just been described operates in the following manner:

The mixture which is to be atomized is first of all prepared by pouring the required amount of concentrated insecticide into the tank 13 and then adding water until the level of the mixture reaches the graduation corresponding to the number of litres of the mixture which are to be atomized. If, for instance, the level of the solution reaches the graduation 10, as shown in FIG. 1, when the tank is completely empty 10 litres of the water-solution mixture will have been atomized.

Once the solution has been prepared, the tank is screwed into the threaded end portion 14 and the delivery pipe supplying the water is connected to the pipe 2 via the connection 3. The applicance is self-priming and therefore ready for use. The operator grips the device by the part 1 and by the revolving handle 17 which he brings into a horizontal position, either towards the left or towards the right according to whether he is left-handed or right-handed. As soon as he squeezes the trigger 8, the valve 6 is pulled against the force of the spring 7, thus allowing the pressurized water to flow into the device and circulate in the annular, elongated space between the two tubes 5 and 10 of the barrel. The flow of water traverses the venturi 18, passing successively into the bores 35 and 41 of the parts 22 and 23. Because of the great speed at which the water flows through the venturi, a vacuum is created inside the chamber 37 which causes the solution 12 to be sucked up, said solution flowing through the inside tube 10, the tubular coupling 31, the annular space 33, the hole 38, the chamber 37 and finally the bore 41 in which it becomes thoroughly mixed with the jet of pressurized water. The mixture is then projected on to the adjustable diffuser 21 which atomizes the product very finely in the desired direction.

In order to clean the appliance, the tank can be filled with ordinary water which can be sucked in by means of the principal jet circulating in the outer tube of the barrel. The appliance can also be cleaned by removing the diffuser 21 and by stopping up the outlet of the bell-shaped member 20 with a finger. The principal jet then circulates following a path including the outer tube 5, the bore 35, the hole 38, the annular space 33, the tubular coupling 31, the inner tube 10 and the tank 12, thus cleaning the whole suction circuit. It should be noted that this method just described can be used for preparing the diluted solution which is to be atomized.

Claims

We claim:

1. An atomizing device in the form of a gun comprising a barrel constituted of an inner tube and a coaxial outer tube, means for connecting the inner tube to a source of water under pressure, means for connecting the outer tube to a supply of liquid to be atomized, said outer tube having an outer end, a venturi member mounted on said outer tube at said outer end thereof, said venturi member having an axis and including a bobbin-shaped portion including spaced opposed annular flanges and an intermediate portion between said flanges, one flange being a downstream flange, the other an upstream flange, said flanges having diameters substantially equal to the inside diameter of said outer tube, said intermediate hollow portion being of reduced diameter, said venturi member having a first hole extending axially through the center of said upstream flange into an inner chamber provided in said intermediate hollow portion, a second hole through the center of said downstream flange into said main chamber, a third hole extending radially through said intermediate hollow portion to form a communication passage between said inner chamber and the exterior of the venturi member, and a tubular coupling integral with said upstream flange and extending eccentrically with respect to said axis of the venturi member, said tubular coupling having a bore which opens into the annular space between said flanges around said intermediate portion, said tubular coupling being sealingly connected to said inner tube of said barrel.

2. An atomizing device as claimed in claim 1 wherein said venturi member comprises two moulded parts, one including an axial tubular portion, the other having an axial bore to receive said tubular portion for joining said portions together.

3. An atomizing device according to claim 1 wherein said flanges have peripheral edges with grooves, and sealing joints in said grooves.

4. An atomizing device as claimed in claim 1 wherein said venturi member includes a tubular portion extending in prolongation of said first hole into said inner chamber substantially at the level of said third hole.

5. An atomizing device as claimed in claim 1 comprising a gripping handle turnably mounted on said barrel for movement between left and right horizontal positions.

6. An atomizing device as claimed in claim 1 comprising a handle attached to said barrel for gripping the gun, said means for connecting said inner tube to a source of water under pressure comprising a pipe mounted in said handle and connected to said inner tube, valve means for controlling communication between said inner tube and said pipe, and a trigger coupled to said valve means for operating the same.

7. An atomizing device as claimed in claim 1 comprising an end portion mounted on said outer tube and encircling said venturi member in sealed relation, and a conical bell-shaped member connected to said end portion and communicating with said second hole.