WO1995010182A1

WO1995010182A1 - Improvements in wiper applicators

Info

Publication number: WO1995010182A1
Application number: PCT/NZ1994/000102
Authority: WO
Inventors: John Frederick Hart; Donald Gordon Isles
Original assignee: C-Dax Systems Limited
Priority date: 1993-10-08
Filing date: 1994-10-06
Publication date: 1995-04-20
Also published as: GB2297467B; GB9607017D0; AU686242B2; GB2297467A; AU7824494A

Abstract

A wiper element for wiper apparatus. The wiper element has an elongate support member (16) and an absorbent material (17) engaged about the support member. A tubular element (22) is located between the support member (16) and the absorbant material (17). The tubular element (22) has a plurality of openings (29) therein. The tubular element (22) is connectable with a liquid supply which feeds liquid under pressure to the tubular element. In wiper apparatus a plurality of wiper elements are mounted within the frame (11) with the wiper elements being located at an angle to the direction (D) in which the frame (11) will normally travel in use. Preferably each wiper element (15) is curved in its length.

Description

IMPROVEMENTS IN WIPER APPLICATORS

This invention relates to a wiper element for a wiper applicator used in the application of liquid chemicals to foliage such as weeds or other undesirable plants.

There are many known types of apparatus for applying liquid chemicals, such as herbicides, to weeds or other undesirable plants such apparatus relying on wipe-on placement of the chemical. The apparatus thus includes one or more wiper elements which can be comprised of rope wicks or fabric/sponge covered tubes, pipes or the like. The latter can, for example, comprise a length of plastics material tube, (eg. PVC) having small perforations or openings along its length with the tube being covered by felt, carpet, sponge or like material.

In New Zealand patent specification 196493 there is disclosed a wipe-on placement applicator comprising a frame (or plurality of frames) which is/are mountable on a tractor or other vehicle such that the frame(s) can be moved over the weeds/plants to which herbicide is to be applied. As disclosed each wiper element is composed of wick rope and a plurality of parallel ropes are mounted across the frame(s) such that the ropes are at an angle to the direction of travel of the frame(s). It is claimed that more effective application of herbicide is achieved because of the angled configuration of the wiper elements as the ropes wipe along the weeds rather than intersect the weeds at right angles.

A common problem with wiper elements is control of the chemical so that even and no over wetting or saturation of the felt, carpet, sponge or like material takes place. Over wetting by over or uneven supply can lead to wastage of the chemical. More particularly over wetting can lead to uncontrolled dripping of the chemical from the wiper element resulting in the chemical dropping onto desirable foliage such as grass etc.

A further problem usually manifests itself when the applicator is tilted or is used on sloping or uneven ground. With most known applicators the chemical tends to drain from the uppermost portion of wiper elements or from those elements which are uppermost. As a consequence a full wiping effect is not always achieved over the total area of the applicator. This often leads to uneven application of the chemical and thus lack of overall killing effect of the weeds or other undesirable plants.

The object of the present invention is to provide a wiper element constructed such as to provide more effective dispensing of chemical to the wiping surface.

Broadly in one aspect the invention provides a wiper element for wiper apparatus said wiper element comprising an elongate support member, an absorbent material engaged about the support member and a tubular element located between said support and the absorbent material, said tubular element having a plurality of openings therein and being connectable with a liquid supply means.

The wiper element according to the present invention can be incorporated into or as part of a frame arrangement which can be attached directly or indirectly to a vehicle such as a tractor or an ATV (all terrain vehicle). Generally the frame will be so mounted that it can be adjusted in height relative to the ground over which it travels. Liquid chemicals such as herbicides will be held in one or more containers which can be mounted with the vehicle or as per the arrangement disclosed in New Zealand patent specification 196493 can be supported by the frame(s). Suitable plumbing enables the chemical to flow via a supply line or lines to individual wiper elements or into a header or plurality of headers which in turn feed the wiper elements. The chemical can flow by either gravity feed or by pressurised delivery means.

Broadly in a second aspect of the invention there is provided wiper apparatus comprising a frame having mounted therein a plurality of wiper elements according to the first broad aspect of the invention, said wiper elements being located at an angle to the direction in which the frame will normally travel in use thereof.

According to a preferred form of the invention the wiper elements are curved in their length with one end of each element coupled to a first or leading side of the frame and the other end coupled to a second or trailing side of the frame. Preferably the first and second sides are parallel.

In the preferred form of the apparatus a wiper element is also provided at each end of the frame with one end coupled to a said first or second side and the other end coupled to an end of the frame.

The apparatus according to the invention can include a further frame with wiper elements pivotally coupled by an end to an end of the first mentioned frame. Preferably the further frame includes a land wheel mounted at or near the end of the frame which is outermost relative to the first mentioned frame. The first mentioned frame is also preferably provided with at least one land wheel. In the preferred arrangement the mounting of the land wheels is adjustable such that the height at which the frame is located above the ground can be adjusted.

The construction of frame, supply conduits, chemical tank and pressured delivery means are well known to those skilled in the art and a detailed description herein is not required. Hence the following description will deal more specifically with the actual construction of a wiper element for use in a wiper applicator.

In the following more detailed description reference will be made to the accompanying drawings in which:-

Figure 1 is a plan view of a wiper applicator frame and plurality of wiper applicators according to one form of the present invention.

Figure 2 is a perspective partially cut away view of a wiper element of the type depicted in Figure 1, Figure 3 is an illustration of the tubular element. Figure 4 is a plan view of a further wiper frame pivotally coupled to the frame of Figure 1 according to a second form of the invention, and Figure 5 is a detailed view of the pivot coupling between the frames.

In the drawings the wiper applicator 10 is shown as including an elongate rectangular shaped main frame 11 having leading and trailing members generally indicated at A and B in Figure 1. Attached to this main frame 11 and projecting downwardly at each end can be a skid which is able to make contact with the ground to ensure the frame and wiper elements do not contact the ground and suffer damage. The leading side member A of the frame 11 can be coupled to a mounting whereby the frame is mountable to a vehicle such that the frame extends rearwardly (or forwardly) of the vehicle. According to one form of wiper apparatus incorporating the invention the frame 11 can be suspended below a support frame which is coupled to, or formed with, a tow bar or tow frame. This tow bar/frame has a hitch for removable coupling to the vehicle. Rearward of the frame 11 the support frame has adjustably mounted thereto land wheels (preferably located one at each corner of the frame 11 and rearward thereof) such that the frame 11 can be pulled over the ground but spaced therefrom as determined by adjustment of the height which the support frame is from the ground.

A tank can be carried by support frame. In a preferred form the tank incorporates a pump and filter arrangement. A power supply (battery) for operation of the pump can also be mounted with the tank or else power can be derived from the vehicle.

A plurality of wiper elements 15 extend between the front and rear longitudinal members A and B of frame 11. As the frame 11 is generally of rectangular shape a shorter wiper element 15 is located at diagonally opposite corners of the frame 11 to extend between the respective longitudinal member A or B and an end transverse member C of frame 11. In the preferred form of the invention as illustrated wiper elements 15 and 15' are of curved configuration.

According to one embodiment of the invention each wiper element 15 comprises a length of tube 16 (preferably of a plastics material such as PVC or a polyethelene gas pipe) which functions as support only and does not contain or convey chemical as with previously known constructions. Tube 16 is covered about its peripheral surface by a material covering 17 such as a woven or non woven fabric or a foamed plastics. Preferably cover 17 is a needle punched wool which has a felt like constitution and appearance. More preferably a synthetic open weave layer 27 or layers is/are integrally contained within the needle punched wool. Layer(s) 27 provides strength and help maintain the integrity of the cover 17. In another preferred form cover 17 could be formed by needle punching synthetic fibres into the wool felt.

In the basic construction shown in the drawings support tubes 16 are simply coupled at each end to the longitudinal frame members A and B by self tapping screws 18 passing diametrically through tubes 16 and into respective member A and B. To give strength at the mounting point bungs, short lengths of rigid tube or rod etc an be fitted into the ends of support tubes 16 with the screws 18 passing therethrough. This prevents the support tubes 16 collapsing or being squashed by the radial force applied by the screw 18.

In the preferred form of the invention as illustrated the area of absorbent material used to form cover 17 is joined, by for example sewing along thread line 28, at opposing longitudinal edges as shown in Figure 2. In the preferred form this join or hem between the opposite longitudinal edges is positioned lowermost so as to increase the wiping area of the absorbent material which comes into contact with the weeds and undesirable plants.

A tab 20 is sewn into the join at one end of the cover 17 this tab 20 having an eyelet 21. When the wiper element 15 is mounted in frame 11 a fastening locates through eyelet 21 and engages with leading member A of frame 11. As a consequence cover 17 is anchored and therefore prevented from moving rearwardly along support tube 16 and/or compressing as a consequence of the action of the weeds and undesirable plants coming into contact with cover 17 due to the forward movement over the ground of frame 11.

Located longitudinally along the upper surface of support tube 16 is a length of thin walled flexible tube 22 which is anchored against movement by tape 23 or some other means of anchoring. This tube 22 is, in the preferred form of the invention, a turbulent twin wall tubular tape (made of polyethylene) and sold under the trade name Chapin. As shown in Figure 3 the tubular tape 22 is formed by overlapping and joining the edges of a length of tape to thereby form the tube. During the manufacturing process small bores 29 are formed in the overlapping portion 30 such that fluid within the tube can pass through the bores and exit therefrom. In the present arrangement the tube is thus anchored in position with the overlapping portion 30 uppermost as shown in Figure 2.

A connector and T junction indicated generally at 25 is inserted in one end of tube 22 while the other end of the tube (not shown) is folded over and clamped by a clip which also extends about tube 16. The T junctions 24 are connected to supply lines 25 which are fed from a main supply line 26 which leads to the pump/tank arrangement used for supplying chemical. As a consequence chemical can flow into tubes 22 and exit via the bores so as to wet the inside of the tubular covering 17. Due to the absorbent nature of the covering the chemical migrates through to the exterior thereof and as the wiper element brushes over weeds and undesirable plants the chemical is applied thereto. In the preferred arrangement of a wiper applicator chemical is supplied to the wiper elements under pressure and more particularly a pressure in the range of 0-1.5 bar but more preferably in the region of 7-10 psi. This can be achieved by the use of a demand pump which cuts off at a pre-set pressure and periodically operates through an electronic control or via a manually operated switch to supply chemical to the wiper assembly.

Upon supply of the chemical under pressure tubes 22 tend to expand as they are filled due to the inability of chemical to flow out of the openings of the circumferential bores at a rate greater than the inflow. Accordingly each tube 22 tends to function as an accumulator and maintains a pressure flow out of the circumferential bores 29 when the pump is not operating. The pressure within the tube 22 dissipates as the outflow continues until such time as pressure is once again built up by the operation of the demand pump.

In another form the moisture content of the absorbent covering 17 can be monitored and the pump cycled electronically according to sensed moisture content. The moisture content can be set by the operator. In another form, the pump can be electronically controlled by a timer which is set by the operator.

As a consequence the siphoning action which is generally experienced with known wiper applicators when the pump ceases operating does not occur with the applicator using the wiper elements of the present invention. Furthermore the accumulator action of the tubes 22 results in chemical being continuously dispensed into the cover 17 even when the applicator is being used on sloping or uneven ground. Thus overall wetting of the cover 17 is achieved thereby ensuring that a total wetted area within the frame exists even in sloping/uneven ground situations.

Furthermore the relatively fine openings of the circumferential bores results in liquid being applied to the covering 17 in a manner that it does not become over wet. In effect the chemical supplied replenishes the covering as chemical is wiped therefrom during operation. This results in a marked reduction in dripping and therefore overcomes the consequential problem which such dripping can cause by coming into contact with desirable foliage.

The present invention thus provides a wiper element which results in better controlled delivery of chemical to the wiping surface and thus largely overcomes the problems associated with known wiper elements. In addition to better control and the marked reduction in the adverse effects of uncontrolled dripping of chemical from the wiper element the present invention leads to more efficient use of chemical resulting in lower chemical usage.

A plurality of wiper elements 15 are mounted by the main frame 11 as shown in Figure 1. As a consequence a space exists between the leading ends of wiper elements 15.

Thus foliage will pass between each pair of leading ends of the wiper elements as the frame is moved in the direction of travel D. As the foliage passes between pairs of wiper elements it will, due to the disposition of the wiper elements, be pulled forward and laid down so that not only will the foliage be wiped by the wiper element forcing the foliage forward and down but also as it lays down it will wipe along the back of the next adjacent wiper element. While it is preferred that the wiper elements be curved as illustrated they can equally be straight.

According to a further form of the invention the wiper elements 15 can be formed such that the outer covering 17 is able to roll on the support tube 16. Thus the action of the wiper assembly being moved over the foliage will result in outer covering 17 rotating and it is believed that this will lead to increased scuff and therefore wetness which can be wiped onto the foliage.

The present invention therefore provides a wiper applicator whereby the foliage initially becomes entrained in the space between adjacent pairs of wiper elements due to the effective combing action resulting from the wiper elements being spaced apart. This can be accentuated when the wiper elements are located beneath the main frame by downwardly projecting legs. Due to the wiper elements being disposed at an angle to the direction of travel the foliage as it proceeds between the pairs of wiper elements, is laid forward and downward such that as described the pair of wiper elements will apply chemical to effectively opposite sides of the foliage. This therefore leads to more effective application of the chemical to the foliage.

To increase the physical width of application of chemical a frame similar to that shown in Figure 1 can be hingedly coupled to each end C of frame 11 (see Figure 4). In this form of the invention frame 11 is formed as part of a trailed wiper apparatus and is therefore suspended from a support frame which has land wheels as previously described herein.

According to this form of the invention the secondary frame(s) 11' is of generally the same construction as that of Figure 1 but in the preferred form is provided with a plurality of short vertical members (not shown) along each long side A' and B' as well as at the corners at the outermost end C of the frame. These upright members are coupled to longitudinal and end members so as to provide reinforcement or strengthening of the frame. Located at the outermost end C the frame is provided with a downwardly projecting skid (not shown) together with a land wheel W' mounted to the lower end of an upright 30 which slidingly engages within a tubular mount 31. A pin (not shown) extending through aligned openings in the upright 30 and tubular mount 31 enable the vertical position of the land wheel W' relative to the frame 11' to be adjusted so that the height of the frame as it travels over the ground can be regulated.

As illustrated in this form of the apparatus land wheels W' are similarly attached to the support frame from which the frame 11 is suspended.

As illustrated in Figure 5 short tubular elements 32 are welded or otherwise attached to the end C of frame 11. These are preferably located where reinforcing struts 33 extend from the support frame to the end member C.

Similarly tubular elements 34 are welded or otherwise fastened to the end C" of frame 11' and preferably these are located where the downwardly inclining reinforcing members 35 (which are mounted to the aforesaid short uprights) join with end member C".

A shaft 36 extends through the aligned bores of tubular elements 32 and 34 with the ends of the shaft 36 engaging in openings in flange plates 37 welded or otherwise fastened to the ends of the side members A and B of frame 11. On even ground frame 11 and frame 11' substantially extend in the same plane. However, frame 11' can via the hinge arrangement incline downwardly or upwardly from the plane of frame 11. Thus, for example, with a secondary frame 11' extending from each end of the main frame 11 one can hinge quite independently of the other such as, for example, one secondary frame 11' inclining upwardly relative to main frame 11 while the other frame may be in the same plane or incline downwardly from the main frame 11. Thus, in addition to providing a greater wiping area, the independent movement of the secondary frames 11' enables the apparatus to traverse uneven ground.

Also, as illustrated in Figure 5, the close hinging of the frames together with the near overlap of the short corner wiper elements 15' a nearly unbroken wipe area across the entire length of the combined frames is achievable. The hinging of the secondary frame 11' allows application of chemicals to undesirable plants and weeds which grow on ground not able to be traversed with other types of weed wipers.

This multi frame form of the apparatus is particularly suited for towing by an ATV vehicle thus resulting in a wider than normal width of application than has hitherto been possible with ATV drawn wiper applicators.

When the apparatus is in a transportation mode the secondary frames 11' are simply pivoted upwardly and their outer ends C joined and pinned or otherwise fastened together. This can, for example, be achieved by providing a coupling between the uppermost ends of the uprights 30 of wheels W. The apparatus can thus be towed solely on the land wheels of the main support frame.

Claims

1. A wiper element for wiper apparatus, said wiper element (15) comprising an elongate support member (16), an absorbent material (17) engaged about the support member (16) and a tubular element (22) located between said support (16) and the absorbent material (17) , said tubular element (22) having a plurality of openings (29) therein and being connectable with a liquid supply means.

2. A wiper element as claimed in claim 1 wherein the absorbent material (17) is a needle punched wool.

3. A wiper element as claimed in claim 2 wherein at least one synthetic open weave layer (27) is integrally contained within the needle punched wool.

4. A wiper element as claimed in claim 1 wherein the absorbent material (17) is formed by needle punching synthetic fibres into a wool felt.

5. A wiper element as claimed in any one of claims 1 to 4 wherein the tubular element (22) is a length of thin walled flattened tube, there being an elongate area (30) of thickened wall section extending for the length of the tube, each of said plurality of openings being in the form of bores (29) passing from the interior of the tube in a radial direction through the thickened wall section (30) to emerge at a face which defines the longitudinal external edge of the thickened wall section.

6. A wiper element as claimed in claim 5 wherein the thickened wall section (30) is located substantially opposite the underside surface of the absorbent material (17).

7. A wiper element as claimed in claim 5 or 6 wherein one end of the tubular element (22) is closed and the other end is provided with a coupling (24) to which an end of a supply conduit (25) can be engaged.

8. A wiper element as claimed in any one of claims 1 to 7 wherein the absorbent material (17) is anchored (20) to the support member (16) such as to resist longitudinal movement thereof on the support member.

9. A wiper element as claimed in any one of claims 2 to 8 wherein the support member (16) is curved at least throughout the major part of its length.

10. Wiper apparatus comprising a frame (11) having mounted therein a plurality of wiper elements (15) according to any one of claims 1 to 8, said wiper elements (15) being located at an angle to the direction (D) which the frame will normally travel in use thereof.

11. Apparatus as claimed in claim 10 wherein each wiper element (15) is curved in its length with one end of each element coupled to a first or leading' side (A) of the frame (11) and the other end coupled to a second or trailing side (B) of the frame.

12. Apparatus as claimed in claim 11 wherein the first and second sides (A and B) are parallel.

13. Apparatus as claimed in any one of claims 10 to 12 wherein a wiper element (15^» ) is also provided at each end of the frame (11) with one end coupled to a said first or second side (A or B) and the other end coupled to an end (C) of the frame (11).

14. Apparatus as claimed in any one of claims 10 to 13 wherein a further frame (ll¹) with wiper elements (15) is pivotally coupled by an end (C") to an end (C) of the first mentioned frame (11).

15. Apparatus as claimed in claim 14 wherein said further frame (ll¹) includes a land wheel (W) mounted at or near the end (C¹) of said further frame (ll¹) which is outmost relative to the first mentioned frame (11).

16. Apparatus as claimed in claim 15 wherein the first mentioned frame (11) is provided with at least one land wheel (W¹).

17. Apparatus as claimed in claim 16 wherein the mounting (30, 31) of the land wheels (W and W¹ ) is adjustable such that the height at which the frame (11 and 11') is located above the ground can be adjusted.

18. Apparatus as claimed in any one of claims 10 to 17 wherein the wiper elements (15) are coupled via supply conduits (25 and 26) to a liquid chemical supply means, said supply means including a demand pump controlled to operate over a period of time whereby said tubular elements (22) expand as a consequence of the pressurised supply of chemical and collapse upon the pump ceasing to operate and the liquid pressure within the tubular element dissipating.

19. Apparatus as claimed in claim 18 wherein the pre¬ determined pressure is in the range of 0-1.5 bar preferably 7-10 psi.