GB2122885A

GB2122885A - Plant treatment device

Info

Publication number: GB2122885A
Application number: GB08219768A
Authority: GB
Inventors: Edward Julius Bals
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-07-08
Filing date: 1982-07-08
Publication date: 1984-01-25

Abstract

A plant treatment device comprises a cup-shaped body (16) with internal screw threads (17) in which is engaged a neck of a non- collapsible, closed liquid container (19), the container having external screw threads (18) on its neck to engage with said screw threads (17) on the body (16). The screw threads (17, 18) do not precisely match and thus define an air path (20) therebetween. A flange of a member (10) is sealingly trapped below said container neck in said body, the member (10) having a depending, cylindrical tubular portion extending out of the body and carrying a wick (11). A groove (15) in the flange of the member (10) allows air to pass along said air path (20) into the container, as liquid flows through the wick. A cap (13) is screw- threadedly engaged on the tubular portion of the member (10) and contains an O-ring (14). Tightening of the cap compresses the O-ring and thus a variation in the capillary force is produced by varying said degree of engagement of the cap on said tubular portion of the member 10. <IMAGE>

Description

SPECIFICATION Plant treatment devices This invention relates to devices whereby individual plants or small groups of plants may be treated with, for example, a weed killer substance, particularly a substance which acts by translocation.

Such devices are hand held and are used to apply weed killer or other substance to individual plants or small groups of plants, where these are situated between other plants not requiring the treatment.

Known devices of this kind include wick which is supplied with treatment liquid and this can be applied as required to the leaves of the plants to be treated. Most such devices however suffer from the disadvantage that the liquid tends to drip from the wick between applications to individual plants and the drips may well fall upon those plants not to be treated. Means for preventing dripping as applied to known devices, have involved complexities such as valves.

It is the object of this invention to provide a plant treatment device in which the wick is not subject to dripping and the device is therefore safe and efficient to use.

In accordance with the present invention there is provided a plant treatment device comprising a member carrying an application wick, a closed container for liquid for supply by capillary action through the wick, the container being connected to the said member, directly or indirectly, by means of screw threads which define between them an air path, through which air can enter the container to allow escape of the liquid through the wick.

This arrangement provides for an initial outflow of liquid into this path to create a negative pressure within the closed container which then ensures a regular feed or liquid from the container through the wick, by the constant hydrostatic pressure established, which can then be counterbalanced by compression of the wick to ensure that liquid is only drawn through the wick when some is applied to a plant surface, the hydrostatic pressure and capillary action (determined by the degree of compression of the wick) otherwise being in balance to avoid dripping.

The invention will now be described by way of example with reference to the accompanying drawing the single figure of which is a crosssectional view of a plant treatment device constructed in accordance with the invention.

The drawing shows a plant treatment device having a member 10 within which is mounted a wick 1 The member 10 has a tubular bore of a size to accommodate the wick and has also an external screw thread 12 to engage within a threaded cap 1 3 containing a compression ring 14 such as an '0' ring. The arrangement is that the cap 1 3 is tightened to compress the ring 14 against the end of the member 10 and also inwardly into tight contact with the wick 1 The end of the wick extending out of the cap is frayed as indicated and its other end is pointed or otherwise reduced in section so as to make it easy to thread through the bore in the member 10.

Tightening of the cap 1 3 determines the spaces between the fibres which make up the wick 11 through which liquid can pass by capillary action, thus allowing a variable capillary force to be exerted by varying the degree of tightening of the cap.

The member 10 has a flange with a groove 1 5 in its face remote from the screw threaded portion. The groove extends radially from the bore accommodating the wick 11 to the external periphery of the flange of the member 10.

The member 10 is located within an aperture formed in one end of a main body 1 6 of the device. This body is generally cup shaped with its aperture accommodating the member 10 in the centre of its base. It is internally screw threaded at 1 7 to engage corresponding external screw threads 18 on the neck of a container 19 for treatment liquid. This may be of any convenient shape and only part of it is shown in the drawing, but it is a closed container made from a material ensuring that it is non-collapsible to allow for the creation of a negative pressure, as previously outlined. As shown the external edge of the flange of the member 10 is trapped between the main body 1 6 and the end of the neck of the container 1 9 and except for the groove 1 5 this forms a liquid tight seal.The groove 1 5 in the face of the flange of the member 10 communicates with the screw thread in the main body 1 3. Also, the screw threads 17, 18 in the main body 16 and in the container 1 9 do not match precisely but there is 'defined outside the screw threads 1 8 of the container 1 9 a helical path indicated at 20 through which air can enter the container through the groove 1 5 to allow escape of liquid through the wick 11.

To the exterior of the body 1 6 there is connected a lug 21 onto which is secured a handle 22 with a knob 23. The length of the handle is such that the wick is conveniently close to the ground to allow individual treatment of plants by direct application of the wick to such plants.

Furthermore, previously referred to, the capillary effect of flow of liquid through the wick is regulated by tightening or loosening the cap 13 in accordance with viscosity or other characteristics of the liquid to be dispensed and this adjustment of the cap 1 3 varies the degree of compression which is applied to the wick 11.

In place of the indirect connection between the member 10 and the container the member may itself have the cap formed integrally with it so that the screw threads thereon are directly engaged with those in the container.

In place of the bottle 19, the handle 22 may be hollow and used as the container for the liquid, if closed at the top and made from a non-collapsible material, the handle, in such a construction, being screwed directly onto the main body 16.

Claims

1. A plant treatment device comprising a member carrying an application wick, a closed, non-collapsible container for liquid for supply by capillary action through the wick, the container being connected to said member, directly or indirectly, so as to define an air path through which air can enter the container to allow escape of the liquid through the wick, and means for providing a variable compression of the wick to produce a variable capillary force.

2. A device as claimed in claim 1, in which said connection of the container to said member is by means of screw threads which define between them said air path.

3. A device as claimed in claim 2, wherein a body of the device is generally cup-shaped with screw threads on its cylindrical interior surface engaging with, but not matching precisely, external screw threads on a neck of the container, thereby to define said air path, and said member having a cylindrical tubular element which depends from said body, said element carrying said wick in a bore thereof, said tubular element being externally screw-threaded and having a cap engaged therewith, the cap containing means which contact said wick so that said variable capillary force can be provided by varying the degree of tightening of the cap.

4. A device as claimed in claim 3, wherein said tubular element has an integral upper cylindrical flange engaged in the bottom of said cup shaped body, said flange being trapped between said body and the end of said neck of the container and forming a liquid tight seal, except for a groove in its upper face which allows air to pass from said air path, into the container.

5. A device as claimed in claim 3, wherein said tubular element is integral with said cup-shaped body.

6. A device as claimed in any one of the preceding claims wherein a hollow handle of the device forms said closed liquid container.

7. A plant treatment device substantially as hereinbefore described with reference to and as shown in the accompanying drawing.