GB2319715A - Wheeled liquid applicator - Google Patents

Abstract

A wheeled dispenser (11), for the controlled dosage of liquids (16), such as herbicides, over a prescribed (ground) surface (21) area, has an integrated handle (13) and liquid reservoir, with a flow controlled outlet (17) discharging liquid from the reservoir on to the rim (18) of a ground running wheel (12), from which it is spread in a controlled manner by (ground) surface contact with the wetted wheel rim.

Description

Weed Wheel The present invention relates to controlled dispensing of liquids and their spread over a prescribed surface area, and is particularly, but not exclusively, concerned with the application of liquid herbicide solution to a ground surface target area.

Various mobile devices are known for dispensing liquids, such as herbicides, fungicides and insecticides, by spraying over a ground surface. Indeed, plant liquid nutrient feeds may also be dispensed in this way.

Similarly, a variety of wheeled liquid marking devices are known for, say, white line boundary marking on hard surfaced roadways and grass playing pitches.

As a dispenser moves over a surface, the discharge coverage path is progressively extended.

It follows that, if the dispenser moves erratically, for example omitting or duplicating some areas, so respectively under and over dosing will arise.

Ground surfaces may vary considerably in terrain contour and vegetation, requiring adaptation of the dispensing technique to preserve effective coverage.

Spraying from remote nozzles is a commonly adopted convenient means of delivery, but this has inherent disadvantages.

Thus, some positive over pressure or head is required to atomise liquid through a spray nozzle, and nozzles themselves are vulnerable to blockage.

Moreover, flow regulation may require elaborate regulator valves or nozzle change according to the liquid dispensed.

Furthermore, the fine atomised airborne spray is vulnerable to disruption by the ambient wind and the spray jet profile and spray distance from the contact surface affects deposition density and coverage.

Dispensing herbicides, insecticides, etc requires precise control to ensure that the correct volume of liquid is dispensed over a given surface area.

Excess herbicide is wasteful and even harmful to wildlife, whilst too little may be ineffective.

Indeed, where toxic chemicals - and the majority of herbicides fall into this category - are being dispensed, Health and Safety Regulations require the operator to have a certificate authorising use of a spraying device.

Liquid is generally discharged, under a gravity head or under pump pressure from a storage tank at a constant rate.

The volume of (atomised) liquid spread over a given surface area - that is the dosage rate - will depend upon the distance between the spray nonle(s) and the surface.

If a spray nozzle is held close to the surface, the spray path coverage will not be as widespread.

It is very difficult to maintain a constant distance between the spray of a hand-held lance and the surface.

For example, if an operator is spraying a surface while walking, the inherent swaying motion will vary the distance between nozzle and ground.

Broadly, (spray) dispensers may be categorised as: personal portable dispensers, with body mounted storage tanks and hand-held lances - typically fitted with jets or motorised spinning heads for controlled droplet formation; manually steerable wheeled trolleys; and self-powered, vehicle-mounted dispensers.

Generally, portable dispensers are necessary for confined or small localised areas such as footpaths verges, headlands, shrub beds, mowing strips, hedge lines, fence lines, kerbs, channels, car parks, industrial sites, utility sites, building sites, golf courses, parks, sports fields, pedestrian areas, airfields and military bases - where the spray boundary specification may be tightly specified, even down to centimetres.

Precision dispensing and portability are difficult factors to combine, since the weight penalty precludes elaborate control mechanisms.

Moreover, the vagaries of individual operator mobility and consistency in following a prescribed route can randomise spray delivery.

Of the personal dispensers, so-called 'Knapsack Sprayers' employ a tank (for liquid to be dispensed) configured as an operator back-pack, supported by a mounting harness.

The knapsack may also incorporate a miniature (say, battery-powered) electric - or more usually hand-operated - pump, feeding the tank contents, through a delivery hose, to a hand held lance or wand.

The lance head itself may embody one or more spray nozzles.

In the vehicle-mounted dispenser category is the so-called Trolley Sprayer' - which has the same basic elements as the 'Knapsack Sprayer', but a larger capacity tank and pump are mounted upon a trolley can be pushed or towed. The spray lance may also be trolley mounted or hand held.

Trolley Sprayers' with fixed spray nozzles or spray booms (and no lance) are less likely to suffer from this because they dispense the liquid from a fixed height - but suffer the other disadvantages of spray techniques.

Self-powered vehicle mounted dispensers allow even greater capacity than the trolley mounted variants.

An object of some aspects of the invention is to enable accurate dosage and localised dispensing of liquid over a surface - with the elimination of wind drift.

According to one aspect of the invention, a liquid dispenser, applicator or spreader, for delivering and applying a controlled dosage of liquid evenly over a surface, comprises a storage reservoir, for liquid to be dispensed, a discharge throat from the storage reservoir, a ground running wheel, a guide at the discharge throat, for applying and dispersing liquid from the reservoir, to outer rim of the wheel, the wheel rim being profiled, to convey liquid from the guide, and spread it over a surface, with which the wheel rim comes into contact, as it is rotated.

A guide handle may be provided to enable an operator to direct the dispenser along a surface to which liquid is to be applied, by a push or pull action.

The wheel (and handle) may be mounted upon or towed by a powered (all terrain/off road) vehicle.

The area of the application is limited to the rim contact.

The width and diameter of the wheel may be varied to vary the delivery rate and capacity.

If liquid is applied to the entire width of the wheel rim, a wider wheel rim will allow application of liquid to a correspondingly wider surface area.

The wheel rim may be made of various materials, such as rubber, plastics or metal.

The wheel rim may be fitted with ground penetrating or breaking spikes, studs or corrugations, in order to promote the introduction of liquid into the ground or onto the leaf surfaces of target weeds.

In spreading herbicide, for example, such protrusions would bruise leaves, encouraging the uptake of translocating or contact herbicides.

The handle and liquid reservoir may be integrated.

The reservoir is conveniently situated so that a lower opening is adjacent to the top of the wheel.

Liquid from the tank can be allowed to flow from the tank, directly onto the rim of the wheel, or through a spreader platten or web, such as an intermediate 'wetting' roller of controlled absorbency, to achieve a more even or uniform rim wetting.

Adaption of the discharge opening in the storage reservoir or tank allows variation in the rate of flow from the tank to the wheel, and thus the amount of liquid applied to the surface, per wheel revolution, ie the dosage rate.

A distributor guide could be provided to guide liquid from the tank onto the wheel rim particularly if the wheel is wide, and liquid is to be spread over its entire rim width.

Alternatively, liquid may be fed to the rim of the wheel from inside the wheel - for example through a network of distribution channels within the wheel hub communicating with outlet holes in the wheel rim.

Some intermediate liquid storage provision could also be embodied in the wheel itself.

Delivery of liquid from the reservoir to the wheel rim may be under a gravity head.

Alternatively, a pump may be used, allowing the rate of dispensing, or dosage, and coverage of the liquid to be controlled, with, say, peripatetic wheel speed.

The amount and rate of liquid dispensed may be regulated or metered by the inclusion of a variable jets, orifices or flow control valves.

There now follow descriptions of some particular embodiments of the invention, by way of example only, with reference to the accompanying diagrammatic and schematic drawings, in which: Figure 1 shows a cross-sectional view of a wheeled liquid dispenser; Figure 2 shows the dispensing action of the dispenser of Figure 1, wheeled over a surface; Figure 3 shows a perspective view of the dispenser shown in Figures 1 and 2; Figure 4 shows a cross-sectional view of an alternative liquid dispenser embodiment; Figure 5 shows the dispensing action of the dispenser of Figure 4, wheeled over a surface; and Figure 6 shows a perspective view of the dispenser shown in Figures 4 and 5.

Referring to the drawings, Figures 1 through 3 show a wheeled liquid dispenser or applicator 11, with a ground surface engaging wheel 12 carried by a handle 13.

The wheel 12 runs upon an axle 23 carried by a fork 22 at the lower end of the handle 13.

The dispenser can thus be pushed or pulled with the wheel 12 in running contact with the ground 21, to rotate the wheel 12.

A portion of the inside of the handle 13 is hollow and acts as an integral bespoke storage reservoir or tank 14 for liquid 16 to be dispensed.

As an alternative to the integral reservoir, a (pre-filled) proprietary container of herbicides (not shown) may be fitted directly to the dispenser 11.

This reduces the risk of spillage, or the operator coming into contact with the herbicide - which may have adverse dermatological or even carcinogenic effects.

An appropriate (say, neck mount) fitting, possibly with an ON/OFF or flow regulator valve, and a mechanical seal breaker, may be incorporated to address such a demountable container.

The tank 14 is filled through a capped fill opening 15 in the handle 13 body.

A liquid level indicator gauge 24 in the tank 14 provides a visual indication of liquid 16.

At the bottom of the handle 13, the storage tank has an outlet 17, with a distributor or guide 19, through which liquid 16 from the tank 14 can be directed to the rim 18 of the wheel 12.

A flow control regulator, such as a rotary valve, may be incorporated in the outlet 17, as both an ON/OFF control, and a means of limiting output from the tank 14.

In order to promote even distribution of liquid 16 over the wheel rim 18, a multiple nozzle array may be incorporated in the guide 19.

However, spray atomisation by the nozzles is not necessary, since the liquid is carried by the wheel rim 18 to the surface 21.

As liquid 16 drips onto the wheel rim 18, it coats the rim circumference 18, so that in turn, as the wheel 12 is rolled along the surface 21, its liquid coated rim 18 comes into contact with and 'wets' the surface 21, as (some of) the liquid 16 is transferred.

Referring to Figures 4 through 6, an (alternative) liquid dispensing device 51 has a handle 53 with an integral liquid reservoir or tank 54.

A (ground) surface running wheel 52 runs upon an axle 63 supported in a fork 62 at the foot of the handle 53.

A hollow portion of the handle 53 acts as a tank 54 for storage of liquid 56 to be dispensed, and a liquid level sight gauge 64 indicates the volume of liquid in the tank.

At the lower end of the storage tank 54, liquid 56 is fed through an outlet 57 into the hub 71 of the wheel 52.

Inside the wheel 52, there is an intermediate hub reservoir 72, feeding radial supply channels 58 running outward to outlet holes 59 on the wheel rim 73.

As the wheel 52 is rolled over a surface 61, liquid 16 is fed onto the area contacted by the wheel rim 73.

Component List 11 dispenser 12 wheel 13 handle 14 (storage) tank/reservoir 15 opening 16 liquid 17 nozzle 18 wheel rim 19 guide 21 (ground) surface 22 fork 23 axle 24 gauge 51 dispenser 52 wheel 53 handle 54 (storage) tank/reservoir 55 opening 56 liquid 57 nozzle (inside wheel) 58 channels 59 outlet holes (wheel rim) 61 surface 62 fork 63 axle 64 gauge 71 wheel hub 72 intermediate (hub) reservoir 73 wheel rim

Claims (8)

1. Claims 1.

   A (mobile/portable) dispenser or applicator (11), for dispensing controlled dosage of liquid (16), over a prescribed surface (21), the dispenser comprising a storage reservoir (14), for liquid to be dispensed, a surface contact running wheel (12), an outlet (17) from the reservoir, a guide (19) at the outlet, for directing liquid to the wheel rim (18), and thence to the surface, by running contact with the wheel rim.
2. 2.

   A dispenser, as claimed in Claim 1, wherein a storage tank (14) for liquid (16) is integrated with a handle (13), from which the wheel is mounted
3. 3.

   A dispenser, as claimed in either of the preceding claims, wherein the guide includes one or more nozzles directed to the wheel rim.
4. 4.

   A dispenser, as claimed in any of the preceding claims, wherein liquid is fed into the wheel hub (57) and thence through distribution channels (58) and outlet holes (59) in the wheel rim (71).
5. 5.

   A dispenser, as claimed in any of the preceding claims, incorporating a regulator or flow control between the storage tank (14) and wheel rim (18).
6. 6.

   A dispenser, as claimed in any of the preceding claims, including a spreader platten or web at the wheel rim.
7. 7.

   A dispenser, as claimed in any of the preceding claims, incorporating ground penetration wheel rim protrusions, to enhance liquid uptake on the surface (21).
8. 8.

   A dispenser, substantially as hereinbefore described, with reference to, and as shown in, the accompanying drawings.