WO2000056143A1

WO2000056143A1 - Improved motor driven applicators

Info

Publication number: WO2000056143A1
Application number: PCT/AU2000/000167
Authority: WO
Inventors: Lazo Krkobabic
Original assignee: Centrogen Holdings Pty Ltd
Current assignee: Centrogen Holdings Pty Ltd
Priority date: 1999-03-18
Filing date: 2000-03-09
Publication date: 2000-09-28
Anticipated expiration: 2001-09-18
Also published as: NZ514256A

Abstract

A hand held driven applicator including: a motor; drive means (115) drivingly connected to said motor, said drive means (115) having a drive housing and an output drive shaft (120); a rotor assembly connected to said output drive shaft (120) for rotation therewith about a vertical axis, said rotor assembly including application means and distribution means, said application means being adapted to make contact with undesired plants in a field, garden, crop or the like for applying liquids particularly weedicides thereto while said rotor assembly is rotating, and said distribution means having a distribution chamber (156) in liquid communication with said application means for supplying liquid to said application means while said rotor assembly is rotating and an inlet opening (158) to said chamber (156) for receiving liquid therethrough; an elongate handle operatively connected to said drive housing by which a user may maintain said rotor assembly proximal to the surface of the field, garden or crop, whereby said application means may apply liquid to selected undesired plants upon contact therewith; a reservoir mounted on said elongate handle remote from said rotor assembly, and supply means in liquid communication with said reservoir and said inlet opening (158) for supplying liquid to said chamber (156) while said rotor assembly is rotating.

Description

" IMPROVED MOTOR DRIVEN APPLICATORS"

TECHNICAL FIELD OF THE INVENTION

This invention relates to motor driven applicators for applying liquids particularly weedicides selectively to undesired plants in a field, garden, crop or the like.

BACKGROUND ART Co-pending International patent application No. PCT/AU98/00279 by the present applicant describes various forms of hand held motor driven applicators (referred to herein as "our earlier applicators") which have a rotor assembly driven by an internal combustion engine or an electric motor via an angle drive offset from the axis of rotation of the rotor assembly. While these previous applicators operate reasonably well, they are not as efficient as desired and also are more expensive to manufacture and maintain than desired. One object of the present invention is to provide a motor driven applicator which is more efficient in its mechanical operation. Another object is to provide a motor driven applicator which allows for easier refilling with liquid to be applied. Another object is to provide a motor driven applicator which is less expensive to manufacture and maintain. The advantages of the invention are embodied in a hand held motor driven applicator in which the rotor assembly is mounted to a central drive shaft whereby an offset drive is not utilised and the rotor assembly is supplied with liquid from a remote reservoir.

DISCLOSURE OF THE INVENTION

With the foregoing in view, the present invention resides broadly in a motor driven applicator including: drive means having a drive housing and an output drive shaft; a rotor assembly connected to said output drive shaft for rotation therewith about a vertical axis, said rotor assembly including application means and distribution means, said application means being adapted to make contact with undesired plants in a field, garden, crop or the like for applying liquids particularly weedicides thereto while said rotor assembly is rotating, and said distribution means having a distribution chamber in liquid communication with said application means for supplying liquid to said application means while said rotor assembly is rotating and an inlet opening to said chamber for receiving liquid therethrough; a reservoir mounted remote from said rotor assembly, and supply means in liquid communication with said reservoir and said inlet opening for supplying liquid to said chamber while said rotor assembly is rotating. Terms such as vertical, horizontal, upper and lower, are used herein for the purpose of description and illustration of the invention in the position it would normally be used for the application of weedicide to a field unless clearly not appropriate and are not intended to restrict the invention to use in any particular orientation.

In another aspect, the invention resides broadly in a hand held motor driven applicator including: a motor; drive means drivingly connected to said motor, said drive means having a drive housing and an output drive shaft; a rotor assembly connected to said output drive shaft for rotation therewith about a vertical axis, said rotor assembly including application means and distribution means, said application means being adapted to make contact with undesired plants in a field, garden, crop or the like for applying liquids particularly weedicides thereto while said rotor assembly is rotating, and said distribution means having a distribution chamber in liquid communication with said application means for supplying liquid to said application means while said rotor assembly is rotating and an inlet opening to said chamber for receiving liquid therethrough; an elongate handle operatively connected to said drive housing by which a user may maintain said rotor assembly proximal to the surface of the field, garden or crop, whereby said application means may apply liquid to selected undesired plants upon contact therewith; a reservoir mounted on said elongate handle remote from said rotor assembly, and supply means in liquid communication with said reservoir and said inlet opening for supplying liquid to said chamber while said rotor assembly is rotating. Preferably, said inlet opening provides access to said distribution chamber from above when in the normal operating position(that is when the axis of rotation of the rotor assembly is vertical) and said supply means supplies liquid to said chamber via a sealed space between said rotor assembly and said drive means. In one form of the invention, said rotor assembly has a central hub (or hub portion) with a sealing face formed on its upper face which cooperates with a seal fitted between said drive housing and said rotor assembly and a liquid supply passage is formed in said seal forming part of said supply means, one end of said passage being in liquid communication with said reservoir and the other end opening to said sealed space, Oor alternatively a supply fitting is sealably mounted to said seal for connection to said reservoir and delivery of liquid to said distribution chamber. It will be appreciated that a similar seal could be mounted on said rotor assembly with the sealing face being formed on the underside of the housing of the drive means. However, in a preferred form, two radially spaced apart seal assemblies are provided, each having one part sealingly secured to said drive housing and another part sealingly secured to said rotor assembly for rotation therewith and adapted to seal against said one part, said seal assemblies forming an annular space therebetween opening to the inlet opening of said distribution chamber, and said supply means terminating in said annular space. It will be appreciated that some chemicals are very corrosive and thus it is preferred that the sealed space be such as to insulate said output drive shaft from the liquid, although a similar sealing arrangement could be provided with only the outer seal assembly enclosing a sealed space about the output drive shaft and having the output drive shaft in the liquid supply path. In a preferred form the seal assemblies are ceramic face seals with one part being operatively secured to the drive housing and one part being secured to the rotor assembly.

In the case of a hand held motor driven applicator, said reservoir preferably is a refillable container and said supply means includes a hose or tube which is connected to said reservoir and said distribution chamber. Advantageously, an operator is able to use such hand held applicator continuously over a relatively large area without refilling as compared to earlier applicators and furthermore, if a clear plastic container is used for the reservoir, the operator can easily maintain a watch on the liquid level to ensure a continuous supply. Additionally, the height of the reservoir creates a positive pressure in the distribution chamber which assists in maintaining a predetermined desired flow rate.

Preferably, said reservoir is connected to said distribution means by two hoses or other suitable conduits with one being arranged to allow flow of liquid from the reservoir to said distribution chamber when the applicator is in the normal in-use position and the other being arranged to vent said distribution chamber to said reservoir. It is also preferred that the hoses or conduits be arranged to allow liquid in the distribution chamber to return to the reservoir if the apparatus is placed in a stowed attitude with the rotor assembly above the reservoir. Upon completion of a days work the applicator can be placed in the stowed position so that any excess liquid in said distribution chamber can return to said reservoir thus preventing or reducing crystallisation of liquid in said distribution chamber or said applicator means which can occur with some weedicides .

In a preferred form of hand held motor driven applicator, said drive means is a gearbox and said elongate handle is connected to the housing of said gearbox with the motor being mounted on the free end of the elongate handle and drivingly connected to the input shaft of the gearbox via a drive shaft housed in the elongate handle, the motor being either an internal combustion engine or an electric motor. However, in another form of the invention, the rotor assembly is direct driven by a small electric motor with the rotor assembly being mounted on the motor shaft or an extension of it, and the elongate handle is operatively connected to the motor housing with a battery pack being mounted at the other end of the handle thus balancing the applicator. If a large battery powered motor is required this could be mounted at the end of the elongate handle remote from the rotor assembly to suitably balance the apparatus and the battery pack could be carried by the operator on his belt or back and be connected to the motor by suitable wires .

In another aspect the invention resides broadly in a motor driven applicator including: a frame assembly adapted to be connected to a prime mover such as a tractor for travel across a field; drive means mounted to said frame assembly for travel therewith, said drive means having a drive housing and an output drive shaft; a rotor assembly connected to said output drive shaft for rotation therewith about a vertical axis, said rotor assembly including application means and distribution means, said application means being adapted to make contact with undesired plants in a field, garden, crop or the like for applying liquids particularly weedicides thereto while said rotor assembly is rotating, and said distribution means having a distribution chamber in liquid communication with said application means for supplying liquid to said application means while said rotor assembly is rotating and an inlet opening to said chamber for receiving liquid therethrough; a reservoir mounted remote from said rotor assembly, and supply means in liquid communication with said reservoir and said inlet opening for supplying liquid to said chamber while said rotor assembly is rotating. In such form of the invention, the reservoir could be mounted on the frame assembly or the tractor thus providing sufficient liquid for many hours of work with the supply means supplying liquid from said reservoir to said chamber via a sealed space between said rotor assembly and said drive means as previously described. BRIEF DESCRIPTION OF THE DRAWINGS

In order that the invention may be more clearly understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention and wherein:

Fig. 1 is a pictorial representation of an applicator according to the present invention;

Fig. 2 is a pictorial representation of the applicator head of the applicator shown in Fig. 1 with the main components in line for assembly, being a rotor assembly, a seal, a rotor cowl, liquid supply fitting and a gearbox;

Fig. 3 is a sectional side elevation of the applicator head shown in Fig. 2 along a diametral plane, in the normal in-use orientation; Fig. 4 is a pictorial representation of the seal shown in Fig. 2;

Fig. 5 is a plan view of the seal of Fig. 4;

Fig. 6 is a sectional elevation of the seal of Fig. 4 along line 6-6; Fig. 7 is an underside plan view of the rotor assembly shown in Fig. 2;

Fig. 8 is a sectional elevation of the rotor assembly o f

Fig. 7 along line 8-8;

Fig. 9 is a pictorial representation of another applicator head according to the invention with the main components in line for assembly, being a rotor assembly, two radially spaced seal assemblies, a rotor cowl and a gearbox;

Fig. 10 is a sectional front elevation of the applicator head of Fig. 9 along a diametral plane;

Fig. 11 is a sectional side elevation of the gearbox of the applicator head of Fig. 10;

Fig. 12 is a sectional plan view of the gear boxes shown in Figs. 3 and 9 along line 12-12; Fig. 13 is a pictorial representation of the bottom cover of the gearbox shown in Fig. 10;

Fig. 14 is a top plan view of the bottom cover of Fig. 13 ;

Fig. 15 is a bottom plan view of the bottom cover of

Fig. 13;

Fig. 16 is an end elevation of the bottom cover of Fig.

13;

Fig. 17 is a pictorial representation of the rotor cowl of the applicator head shown in Fig. 9, and

Fig. 18 is an elevation of the rotor cowl of Fig. 17.

DETAILED DESCRIPTION OF THE INVENTION

The hand held motor driven applicator 10 illustrated in Fig. 1 includes an applicator head 11 having four main components being a rotor assembly 12, a rotor cowl 13, a seal 14 and an angle drive gearbox 15, the rotor assembly being powered by a small two stroke petrol engine 16 spaced from the applicator head and transferring rotary drive to the gearbox via a drive shaft 17, the shaft being housed in a hollow tube 18 which is secured at its upper end to the engine frame and at its lower end to the housing 19 of the gearbox. The engine, drive shaft and shaft housing are of the type used on hand held motor driven brush cutters but the angle drive is specially designed and constructed for the present invention.

The rotor assembly is fitted to the output shaft 20 of the angle drive gear box 15 for rotation therewith in the rotor cowl which is secured to the bottom plate 21 of the gearbox housing by bolts 22 which engage in threaded apertures provided in thickened portions 23 of the side wall 24 of the housing as more clearly shown in Figs. 2 and 12. It will be appreciated that the applicator can be operated in a manner similar to that of the earlier applicators described in International Patent Application No. PCT/AU98/00279.

The angle drive gear box has some similarities with angle drive gear boxes of the type used on hand held brush cutters having an inclined input shaft and a vertical output shaft. However, the gearing arrangement is a two stage planetary system in order to achieve the desired speed reduction. The inclined input shaft 25 has a bevel gear 26 thereon which co-operates with a complementary beveled gear 27 secured to an upper vertical shaft 28. The upper end of the shaft 28 is mounted in an upper bearing 29 and a spaced lower bearing 30 which in turn are mounted in the gearbox housing 19. At its other end the shaft has a sun gear 31 mounted thereon with a central recess 32 provided in its underside in which an upper bearing 33 is mounted for supporting the inner(or top)end of the output shaft 20. The output shaft is also supported in a lower bearing 34 spaced from the bearing 33 and mounted in the bottom plate 21. In this applicator, drive is transferred from the sun gear 31 to eight planetary gears 37 which engage internal gear 35 fitted to the side wall 24 of the housing 19, the planetary gears in turn being shaft mounted on a ring gear 38 thereby causing it to rotate. The ring gear 38 coacts with a lower sun gear 39 which is mounted on a bearing 40 which in turn is secured to the output shaft 20. The lower sun gear in turn coacts with the eight lower planetary gears 41 mounted on the lower arm gear 42 causing it to rotate as well as the output shaft 20 which is thereto secured. The gearbox in this applicator achieves a speed reduction of about eleven to one. As more clearly shown in Figs. 7 and 8, the rotor assembly 12 has a central hub 51 which is screw threadedly mounted on the output shaft 20 with a wall 52 formed about the hub and spaced radially from it, and a disk 53 extending outwardly from the hub and the wall, the hub, the wall and the disk together forming an annular distribution chamber 56 adapted to store liquid therein. A plurality of rope wicks 57 (shown schematically) are attached to the underside of the disc 53 with their inner ends extending into the chamber and are adapted to apply liquid chemical to undesired plants upon rotation of the rotor assembly in a manner similar to that described in relation to our earlier applicators. It will be seen that the disc 53 has a flat upper surface 53a with a circular slot 58 provided therein coaxial with the axis of rotation of the rotor assembly and extending about the hub to provide an inlet opening into the distribution chamber 56. The hub 51 extends above the disc 53 and its cylindrical outer face provides a sealing face 51a for the inner lip 63 of seal 14. As can be seen more clearly in Fig. 3, the seal is fitted between the cowl 13 and the upper face of the disc 53, the upper face of the seal abutting the underside face of the cowl and being stationary therewith while the outer lip 62 of the seal sealingly engages against the upper face 53a outside the slot 58 and the inner lip 63 as the rotor assembly rotates. It will be appreciated that if a cowl is not included, the seal will be fitted between the bottom cover 21 and the disc 53 and operate in the same manner. Effectively the seal acts to provide a sealed annular space 64 which provides access for supplying liquid to the storage chamber 56 via the slot 58 as the rotor assembly rotates. A liquid supply fitting 69 is fitted in a recess 65 provided in the seal to gain liquid access to the annular space as will be described later.

Liquid is supplied to the storage chamber 56 from a reservoir 66 mounted on the handle 18 adjacent the motor via a plastic tube 67 (shown only in part in Fig. 2). The plastic tube is secured to the gear box housing 19 by a cover plate or clip 68 shown in Fig. 2 and is connected to a supply spigot 70 of the liquid supply fitting 69 which communicates with an outlet spigot 71 which protrudes into the storage chamber through the slot 58 via a supply passage through the fitting. A vent passage also extends through the supply fitting parallel to the supply passage opening in the annular space slightly above the outlet spigot and is connected to a vent tube 72 which opens in the reservoir 66 above the normal full working liquid level via another spigot 75. It will be understood that the outlet spigot remains in a stationary position and liquid can be supplied to the storage chamber while the disc is rotating and it will also be seen that the seal 61 prevents the egress of liquid from the storage chamber and the ingress of dirt and dust.

In use, the reservoir 66 is filled with weedicide or other liquid to be applied to the weeds in a crop or around trees and the liquid flows through the tube 67 into the distribution chamber 56 via the supply fitting 69 and outlet spigot 71 whether the rotor assembly is stationary or rotating. As the applicator is used, the liquid continues to flow in as space in the distribution chamber becomes available. If the rotor assembly requires replacement or if the seal 61 requires replacement the rotor assembly can be simply unscrewed from the output shaft and either component replaced. When the applicator is stood up at the end of a days work the liquid in the storage chamber returns to the reservoir via the vent tube and the supply tube becomes the vent.

The hand held motor driven applicator head 111 illustrated in Fig. 9 is very similar to that of Fig. 2 and accordingly corresponding components have been referenced by the same numbers unless clearly not appropriate, but prefaced by a "1". One difference is that the unitary seal 14 has been replaced by two radially spaced seals 114a and 114b. Seal 114a includes a soft component 114ax which is fixed to the bottom plate 121 of the gearbox 115 and a hard component 114ay which is fixed to the rotor disk 153 via an insert 150 fitted in a recess 149 and sealingly held therein by an 0-ring (not shown) in groove 148. This arrangement reduces manufacturing costs . ,The two components of each seal assembly abut against their respective sealing faces as known in the art of mechanical seals. The seal 114b has two similar components 114bx and 114by which are mounted radially inward of the components of seal 114a with the soft component being fixed to the bottom plate and the hard component to the disk so as to form an annular space between the two seals through which liquid may enter the annular distribution chamber 156 around the hub 151 along path "A" through opening 158. In this case it can be seen that the bottom plate of the gearbox has two concentric hub portions 191 and 192 (as more clearly shown in Figs. 11 and 16) extending downwardly on which the seal components 114ax and 114bx are mounted and the liquid supply passage 171 opens through the lower face of hub portion 191 between the two seals as can be seen more clearly in Fig. 11. A vent passage 172 also opens through the same face but is circumferentially spaced from the supply outlet as more clearly shown in Figs. 13 to 16. Advantageously, the two seals operate independently, and thus can accommodate significant imperfections in the disk 153 without leakage of liquid from the distribution chamber 156. A supply tube 167 and a vent tube 173 (not shown) are connected to passages 171 and 172 respectively via standard BSP fitings 174 screwed into the passage inlet openings 171a and 172a respectively as shown in Fig. 11. Both tubes are then connected to the supply reservoir 166 which is mounted on the elongate handle 118 in the same manner as described in relation to Fig. 1. In this applicator, the inner end portions of the wicks 157 (not shown) are retained in the distribution chamber by glands (not shown) and their outer ends are held in rings 199 formed at the periphery of the disc by similar glands although other means of retention may be suitable.

The foregoing description has been given by way of illustrative example of the invention, and many modifications and variations which will be apparent to persons skilled in the art may be made without departing from the spirit and scope of the invention as herein disclosed.

Claims

1. A motor driven applicator including: drive means having a drive housing and an output drive shaft; a rotor assembly connected to said output drive shaft for rotation therewith about a vertical axis, said rotor assembly including application means and distribution means, said application means being adapted to make contact with undesired plants in a field, garden, crop or the like for applying liquids particularly weedicides thereto while said rotor assembly is rotating, and said distribution means having a distribution chamber in liquid communication with said application means for supplying liquid to said application means while said rotor assembly is rotating and an inlet opening to said chamber for receiving liquid therethrough; a reservoir mounted remote from said rotor assembly, and supply means in liquid communication with said reservoir and said inlet opening for supplying liquid to .said chamber while said rotor assembly is rotating.

2. A hand held motor driven applicator including: a motor; drive means drivingly connected to said motor, said drive means having a drive housing and an output drive shaft; a rotor assembly connected to said output drive shaft for rotation therewith about a vertical axis, said rotor assembly including application means and distribution means, said application means being adapted to make contact with undesired plants in a field, garden, crop or the like for applying liquids particularly weedicides thereto while said rotor assembly is rotating, and said distribution means having a distribution chamber in liquid communication with said application means for supplying liquid to said application means while said rotor assembly is rotating and an inlet opening to said chamber for receiving liquid therethrough; an elongate handle operatively connected to said drive housing by which a user may maintain said rotor assembly proximal to the surface of the field, garden or crop, whereby said application means may apply liquid to selected undesired plants upon contact therewith; a reservoir mounted on said elongate handle remote from said rotor assembly, and supply means in liquid communication with said reservoir and said inlet opening for supplying liquid to said chamber while said rotor assembly is rotating.

3. A motor driven applicator including: a frame assembly adapted to be connected to a prime mover such as a tractor for travel across a field; drive means mounted to said frame assembly for travel therewith, said drive means having a drive housing and an output drive shaft; a rotor assembly connected to said output drive shaft for rotation therewith about a vertical axis, said rotor assembly including application means and distribution means, said application means being adapted to make contact with undesired plants in a field, garden, crop or the like for applying liquids particularly weedicides thereto while said rotor assembly is rotating, and said distribution means having a distribution chamber in liquid communication with said application means for supplying liquid to said application means while said rotor assembly is rotating and an inlet opening to said chamber for receiving liquid therethrough; a reservoir mounted remote from said rotor assembly, and supply means in liquid communication with said reservoir and said inlet opening for supplying liquid to said chamber while said rotor assembly is rotating.

4. A motor driven applicator according to any one of Claims 1, 2 and 3, wherein said inlet opening provides access to said distribution chamber from above when in the normal operating position and said supply means supplies liquid to said chamber via a sealed space between said rotor assembly and said drive means .

5. A motor driven applicator according to Claim 4, including a first seal assembly mounted between said drive housing and said rotor assembly, said seal assembly having one part sealingly secured to said drive housing and another part sealingly secured to said rotor assembly for rotation therewith and adapted to seal against said one part, said seal assembly enclosing a sealed space opening to the inlet opening of said distribution chamber, and said supply means terminating in said sealed space.

6. A motor driven applicator according to Claim 5, including a second seal assembly spaced radially inward from said first seal assembly said second seal assembly having one part sealingly secured to said drive housing and another part sealingly secured to said rotor assembly for rotation therewith and adapted to seal against said one part, said two spaced apart seal assemblies forming an annular space therebetween opening to the inlet opening of said distribution chamber, and said supply means terminating in said annular space.

7. A motor driven applicator according to any one of Claims 1, 2 or 3 , wherein said rotor assembly has a central hub or hub portion with a sealing face formed on its. upper face which cooperates with a seal fitted between said drive housing and said rotor assembly, said seal having a liquid supply passage provided therein forming part of said supply means, one end of said passage being in liquid communication with said reservoir and the other end opening to the inlet of said distribution chamber.

8. A motor driven applicator according to any one of Claims 1, 2 or 3 , wherein said rotor assembly has a central hub or hub portion with a sealing face formed on its upper face which cooperates with a seal fitted between said drive housing and said rotor assembly, said seal having a liquid supply fitting mounted therein and said liquid supply fitting having a passage therethrough forming part of said supply means, one end of said passage being in liquid communication with said reservoir and the other end opening to the inlet of said distribution chamber.

9. A motor driven applicator according to any one of Claims 1, 2 or 3, including vent means for venting said distribution chamber to said reservoir.

10. A motor driven applicator according to Claim 9, wherein said supply means includes a first hose or tube and said vent means includes a second hose or tube.

11. A motor driven applicator according to Claim 10, wherein said first and second hoses are arranged so that liquid flows from said reservoir to said distribution chamber through said first hose and said distribution chamber is vented to said reservoir through said second hose when said applicator is in the normal in-use position , and liquid flows from said distribution chamber to said reservoir through said second hose and said reservoir is vented to said distribution chamber through said first hose when said applicator is inverted to a stowed position in which said rotor assembly is above said reservoir.

12. A motor driven applicator according to Claim 2, wherein said drive means is a gearbox and said drive housing is the housing of said gearbox, said elongate handle being connected to the housing of said gearbox and said motor being mounted on the free end of said elongate handle and drivingly connected to the input shaft of said gearbox via a drive shaft house.d in said elongate handle.

13. A motor driven applicator according to Claim 10, wherein said reservoir is mounted on said frame assembly.

14. A motor driven applicator as hereinbefore described with reference to Figs. 1 to 8.

15. A motor driven applicator as hereinbefore described with reference to Figs. 7 to 16.

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