GB2136321A - Spraying equipment - Google Patents

Abstract

In spraying equipment comprising a fluid supply duct connected to a container, a rotary atomising disc and a motor for driving the disc, the container of the fluid is a flexible bag, and may be accommodated in a rigid support such as a cardboard box. A plug 72 on the duct can be pushed into a socket 86 in the container so that flanges 82, 94 abut with and clip 96 holding the flanges together. <IMAGE>

Description

SPECIFICATION Spraying equipment This invention relates to spraying equipment, particularly, although not exciusively, equipment for spraying herbicides.

According to the present invention, there is provided spraying equipment comprising a spraying head provided with a rotary atomising disc and a motor for driving the disc, the equipment, further comprising a container for liquid to be sprayed and a supply duct for conveying the liquid from the container to the disc, the container comprising a flexible bag which collapses as liquid flows from it.

The connector may comprise a first element attached to the bag and a second element attached to a fluid line, the first element having an outer tubular portion comprising a socket and provided at its free end with a flange, and an inner tubular portion comprising a nozzle for communication with the interior of the container, the second element comprising a body for sealing engagement within the socket, the body having a flange for abutment with the flange of the first element, a fitting for connection to the fluid line and an opening which communicates with the fitting and which receives the nozzle when the body is inserted into the socket, the connector further comprising a clip element for engagement with the flanges to retain the body of the second element within the socket of the first element.

The nozzle of the first element may include a breakable seal, such as a rupturable diaphragm, which must be broken before the contents of the container can be discharged.

In a preferred embodiment, the clip element is part circular, having an arcuate circumferential wall from opposite axial ends of which extend inwardly-directed retaining walls. In use, the flanges of the first and second elements are clamped between the retaining walls.

For a better understanding of the present invention, and to show how it may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a perspective view of spraying equipment; Figure 2 is a partly sectioned view taken along the line Il-Il in Figure 1; Figure 3 is a partly sectioned view taken along the line Ill-Ill in Figure 1; Figure 4 is a partial end view taken in the direction of the arrow IV in Figure 3; Figure 5 is a perspective view of an outlet fitting for a liquid container; and Figures 6, 7 and 8 are perspective views of respectively, three elements of the outlet fitting of Figure 5.

Referring to Figure 1, the spraying equipment comprises a support tube 2 which is connected at one end to a supply assembly and carries at the other end a spraying head 6. The supply assembly 4 comprises a battery carrier 8 to which a battery 10 is connected and which is provided with a hollow handle 12. The handle 12 is mounted between front and rear limbs 14 and 16 of the battery carrier 8 and is connected at its rear end to a fluid supply line 18. Near its front end, the handle 12 is provided with an on/off tap 20, and at its extreme end it is connected to the support tube 2 by a fitting 22.The interior of the handle 12 thus provides an intermediate duct, a supply tube 38 communicating with this intermediate duct and consequentiy with the fluid supply line 1 8. As can be seen from Figure 2, the supply tube 38 is provided at its end with a flanged connector 40.

An O-ring 42 is compressed between the connector 40 and a shoulder provided on the handle 1 2 under the action of the fitting 22.

The battery 10 is connected to the bracket 8 by terminal nuts 24 (only one of which is visible in Figure 1). The two terminals are connected by a lead 26 to an adjustable voltage regulator 28 controlled by a knob 30. The output of the voltage regulator 28 is connected by a short lead 32 to an on/off switch 34. The on/off switch 34 is connected by a further lead 36 to the spraying head 6. The electrical circuitry is disclosed in greater detail in my co-pending patent application No. 8305003 (Serial No. 2131327).

As will be appreciated from Figures 1 and'2, both the lead 36 and the supply tube 38 extend down the support tube 2. The lead 36 extends through an opening 44 in the front limb 14 of the bracket 8 and through an opening 46 in the support tube 2.

As shown in Figure 3, the spraying head 6 comprises a body 48 which accommodates an electric motor 50 having an output spindle 52.

The lead 36 is connected to the input terminals of the motor 50. The output spindle 52 of the motor carries a rotary atomiser disc 54, the spindle 52 being a friction fit within a bore 56 in the disc 54.

The body 48 has three angularly spaced passages 58. Each of these passages is inclined to the axis of the motor 50 such that it extends inwardly and towards the atomising disc 54. At the inner end of each passage 58 there is a jet 60 having a restrictor passage 62. The diameters of the restrictor passages 62 of the jets are different from one another. The restrictor passages 62 open into a cavity 64 in the end of the body 48.

The cavity is defined by a circumferential wall which terminates at a lip 66 defining, with the disc 54, an annular outlet slot 68.

The radially outer portion of each passage 58 constitutes a socket for receiving an end fitting 70 of the supply tube 38.

The end of the fluid supply line 18 away from the handle 12 is provided with a plug element 72 (Figures 5 and 7). The plug element 72 has a barbed connector 74 which fits into the supply line 1 8 and communicates with a passage 76 extending through the plug element 72. The plug element has a cylindrical portion 78 carrying an 0ring 80. There is a flange 82 at the end of the cylindrical portion nearer the connector 74.

The plug element 72 is adapted to mate with a socket element 74 (Figures 5 and 6). The socket element 84 is fitted to a container of liquid to be dispensed by the spraying equipment. The container is a collapsible bag, such as is sometimes used for packaging wine, and may be supported in a rigid box, for example of cardboard.

The socket element 84 comprises a cylindrical socket 86 for receiving the cylindrical portion 78 of the plug element 72. The socket 86 has an end wall 88 from which projects a hollow spigot 90 which is a close fit in the opening 76 in the plug element 72. Before first use, the through passage of the spigot 90 is closed by a breakable diaphragm 92. The interior of the spigot 90 opens into apace enclosed by an apertured skirt 94 which, in use, would be disposed within the container to which the socket element 84 is fitted.

Thus, to connect the supply tube 1 8 to the container, the diaphragm 92 is pierced and the plug element 72 is inserted into the socket 86 until the flanges 82 and 94 abut one another. To secure the plug element 72 within the socket 86, a clip element 96 (Figure 8) is provided. This clip element has a circumferential wall 98 the ends of which subtend an angle of slightly greater than 1 800. The axial edges of the circumferential wall 98 are provided with radially extending walls 100 which, when the clip element 96 is fitted to the mating plug element 72 and socket element 84, extend on opposite sides of the abutting flanges 82 and 94, as shown in Figure 5.

In use of the equipment, the fluid supply line 18 is connected to the flexible bag in the manner described above and the bracket 8 is connected to the battery 10 by the nuts 24. The control rocker of the tap 20 is depressed to allow liquid, such as herbicide, from the bag to descend under the action of gravity through the handle 12 and the supply tube 38 to the spraying head 6, where it passes through the end fitting 70 and the restrictor passage 62 into the cavity 64. As the liquid leaves the bag, the bag collapses. The switch 34 is turned to the "on" position which causes power to be supplied from the battery 10 to the motor 50 to spin the atomiser disc 54. The liquid flows as an annular stream through the aperture 68 and is ejected by centrifugal force from the atomising disc 54 over the entire periphery of the atomiser disc.The width of the annular gap 68 is carefully selected, in dependence of the viscosity of the liquid to be sprayed, so as to ensure that an even distribution of the liquid reaches the rotary atomiser disc to achieve all-round spraying.

By controlling the voltage applied to the motor 50 by means of the voltage regulator 28, the speed of rotation of the atomiser disc 54 can be adjusted. Such adjustment will vary not only the distance over which the liquid is ejected from the disc 54, but also the size of the droplets into which the liquid is broken up as it leaves the atomising disc 54. Thus, the higher the speed of rotation, the greater the spreading width and the smaller the droplet size. In the embodiment illustrated, the speed of rotation of the atomising disc 54 is variable between approximately 200 and 4000 rpm. The disc 54 shown fitted to the output shaft 52 has a diameter of approximately 20 mm and will, at low speed, spray the liquid over a circular area having a diameter of approximately 10 cms with a large droplet size.

Increasing the speed reduces the size of the droplets but will increase the diameter of the sprayed area to approximately 60 cms.

In order to achieve both a desired droplet size and a desired spreading width, the atomizing disc 54 may be repiaced by alternative discs 54', and 54", illustrated in Figure 3. The disc 54' has a diameter of approximately 30 mm and, at low speed, will spray over a circular area of approximately 30 cms and, at low speed, will spray over a circular area of approximately 30 cms diameter with large droplets and, at high speed, an area of approximately 1.2 metres diameter with small droplets. The smaller disc 54" has a diameter of approximately 10 mm and, at low speeds, will spray over an area of approximately 5 cms diameter with large droplets and an area of approximately 45 cms diameter with finer droplets, although the variation of droplet sizes at all spraying widths is likely to occur with the smaller disc.

The discs are a simple push fit on the output shaft 52 of the motor 50. However, in order to withdraw a disc from the output shaft 52 without damaging the periphery of the disc, a suitable tool may be provided for insertion into the passage 56.

For example, the tool may comprise a screw threaded shank and the passage 56, at least at the end away from the output shaft 52, may be tapped to receive the shank.

Adjustment of the flow rate of liquid to the cavity 64 and thus from the disc 54 may be achieved by inserting the fitting 70 into the appropriate socket 58, since the flow rate will be controlled by the diameter of the restrictor passage 62 in the jet 60. These passages may, for example, range from 0.75 mm to 2 mm.

The spraying equipment described with reference to the drawings provides simple adjustment of spraying width and droplet size to meet the requirements of different circumstances.

For example, in windy conditions, it is desirable to have a large droplet size in order to avoid wind drift.

The use of the connector described with reference to Figures 5 to 8 provides a convenient method of connecting the spraying equipment to containers of ready-to-use weed killing chemicals, i.e. chemicals which require no mixing by the operator. The connector enables the spraying equipment to be "plugged in" directly to the container in which the chemical is supplied, thus avoiding any handling of the chemical by the operator.

Although the present invention has been described with reference to the spraying of herbicides, it is also suitable for other spraying operations, such as the spraying of lubricants or coating compositions such as varnish.

Claims (7)

1. Spraying equipment comprising a spraying head provided with a rotary atomising disc and a motor for driving the disc, the equipment further comprising a container for liquid to be sprayed and a supply duct for conveying the liquid from the container to the disc, the container comprising a flexible bag which collapses as liquid flows from it.

2. Spraying equipment as claimed in claim 1, in which the bag is disposed in a rigid support.

3. Spraying equipment as claimed in claim 2, in which the rigid support is a cardboard box.

4. Spraying equipment as claimed in any one of the preceding claims, in which the supply duct is releasably connected to the bag.

5. Spraying equipment as claimed in claim 4, in which the supply duct is releasably connected to the bag by a plug and socket connector.

6. Spraying equipment as claimed in claim 8, in which the connector comprises a first element attached to the bag and a second element attached to a fluid line, the first element having an outer tubular portion comprising a socket and provided at its free end with a flange, and an inner tubular portion comprising a nozzle for communication with the interior of the container, the second element comprising a body for sealing engagement within the socket, the body having a flange for abutment with the flange of the first element, a fitting for connection to the fluid line and an opening which communicates with the fitting and which receives the nozzle when the body is inserted into the socket, the connector further comprising a clip element for engagement with the flanges to retain the body of the second element within the socket of the first element.

7. A flexible bag containing liquid herbicide and having an outlet for connection to spraying equipment for delivering the herbicide.