NZ214608A - Pruning cutters; treatment liquid applied to stem end during cutting - Google Patents

Description

214608 0 N.Z. PATENT OP Fire' 16 DEC J986 RECgfypn PATENTS FORM NO; 5 Fee No. 4: $150.00 THE PATENTS ACT 1953 COMPLETE SPECIFICATION After Provisional No;214608 Dated: 18th December 1985 TITLE: "CUTTER" V '> We DR. RONALD FRANCIS HENZELL, an Australian citizen of 33 Dalethorpe Avenue, Hamilton, New Zealand, MURRAY RICHARD BRISCOE, a New Zealand citizen of 7 Panair Crescent, Hamilton, New Zealand, ROBERT ALAN MILLS, a British citizen of 13 Nevada Road, Hamilton, New Zealand, BARRY ERNEST STEVENSON, a New Zealand citizen of 171 Knighton Road, Hamilton, New Zealand and RONALD GRANT PATTERSON, a New Zealand citizen of 65 Livingstone Avenue, Hamilton, New Zealand hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: *4-". ■»> •"• m"' - " / 214608 This invention concerns devices for severing the stems of plants. j ! i Such devices are used in large numbers for pruning vines and gathering cut flowers. ! New Zealand Patent No. 187 490 discloses apparatus which severs the stem of a plant j and sprays atomised treatment liquid onto the severed end of the stem in order to j prevent deterioration of the tissue exposed by the cut.

This apparatus depends on a compressed air supply and a supply line which must follow the operator through the vines or flowers as he works. The application of the treatment liquid as an aerosol means that the operator must work in an atmosphere with a high concentration of the reagent being applied. This would be unacceptable over long periods moreover it is wasteful of the reagent. Utilisation of reagent is also minimal because the area exposed for absorption may be limited to the exposed end of the stem.

The method aspect of this invention provides a method of severing a plant stem and simultaneously applying a treatment liquid to the stem characterised in that as part of the cutting action the stem is urged against a surface which is at least partly covered with the liquid.

Preferably the action of urging the stem squashes the stem tissues and increases the liquid contact area. Preferably the treatment liquid is applied to the coating surface as a gel and in metered quantity. The gel may contain a hormone for example, a growth inhibiting hormone in order to suppress the re-establishment of the plant in the area of the cut.

The apparatus aspect of this invention provides a hand held applicator capable of supplying a dose of treatment liquid to a selected site on a plant comprising blade means capable of severing the plant stem and a dosing means capable of applying to the severed site a dose of treatment liquid.

Preferably one motion imparted by the operator provides both severing and dosing.

SUGOQ The applicator preferably achieves the simultaneous actions by a jaw action. Accordingly the applicator may have a pair of jaws wherein one jaw acts as an anvil and the other supports a blade which closes towards the anvil. A special action is required however because to be fully effective the dosing must be accompanied by a crushing action. Instead of the cutter closing on the anvil we prefer to provide an aperture in the anvil so that the blade can pass through the aperture during the closing action while still leaving the anvil to co-operate with a corresponding anvil surface on the opposite jaw in order to exert a bruising action on the tissue which is severed.

Preferably the liquid is delivered to the anvil surface over which it spreads so that the action of the cutter closing on the plant stem causes the severed parts of the plant stem adjacent the blade to contact the coated anvil. Thus the applicator is particularly suited to severing plant stems. A stop may limit entry between the jaws and the tissue to be severed so as to locate the tissue between the blade and the anvil ensuring that the tissue is subjected to both severing and bruising.The feed motion for the dosing action may be a feed screw arranged to advance a plunger of a syringe and a ratchet feed mechanism linked to a lever which also provides a severing action, such ratchet feed serving to rotate the feed screw.

Sufficient mechanical advantage for pruning and light work is obtainable. For tougher stems the applicator may be gas powered for example by LPG or the like, used as either a source of fuel gas ignitable with a piezo-generated spark or as a source of compressed gas which reciprocates a ram arranged to work as a motor.

One embodiment of the invention is now described by way of example with reference to the accompanying drawings in which: Fiqure 1: is a front elevation Figure 2; is a side elevation Fiqure 3; is a section through the body of the applicator on axis A-A ii ,-!AK "'OrC': > H.u-'osg; 214608 Figure 4: is a section through the handle of the applicator on axis B-B.

Referring now to the drawings, the applicator has a cranked body 2 made largely of sheet metal with a syringe breech 4, a handle 6 which tilts on body 2 through pivot pin 8. The upper forward end of the body 2 carries a fixed jaw 10 which is inclined to the axis of the body. The jaw supports a blade 12, the depth of which exceeds the depth of the plant tissue to be cut for example a kiwifruit cane.

The construction of the body 2 can be seen more clearly in figure 3. The blade is secured to a blade bed 14 by rivets 16. On both sides of the blade there are static jaw faces 18 against which the cane is crushed by the corresponding faces 20 of the handle 6. The handle 6 has a central slot 22 through which the blade passes during the cutting stroke. A rod 24 extends from the static jaw faces 18, along one non-cutting edge of the blade 12. The rod acts as a stop for the cane ensuring that when its circumference enters the gap separating the jaws, the cane lies directly in the path of the blade 12 and is then subjected to crushing by the jaw faces 18, 20. The jaw faces of the handle are V-shaped subtending a obtuse angle of about 160 degrees. The static jaw face 18 against which they close are of complementary shape. This merely assists to centre the cane during the onset of cutting. In the cutting stroke, the rod stop passes through the slot along with the blade. Fingerguards, 26, 28 on the handle and body localise the grip. The breech 4 extends the entire length of the body in order to accommodate a disposable plastic 20ml syringe 30.

Figure 3 shows a recess 32 in the body which receives the barrel end of the syringe. A cavity 34 in the recess accommodates the syringe nozzle and a passage 36 leads from the cavity 34 to a port 38 in one half of the static jaw face 18 which is visible to the operator. By this path the contents of the syringe can reach the squashed remnant of the severed cane (not shown) but not the cane end which falls to the ground. The cranked end of the body 2 ends in a threaded eye 40 for supporting one end of a feed screw 42. The opposite end of the feed screw 42 is supported in the bore 44 of a lug 46 projecting from body 2. •• i-> •• 'I- 0 The feed screw projects through the bore and an overhung ratchet wheel 48 is fixed to the shaft. Pawl 50 ensures unidirectional rotation of the shaft. The ratchet is advanced one tooth at a time, each time the jaws are closed. We have found it advisable to have the feed screw turn late in the cutting action. Consequently the ratchet wheel 48 is rotated by a spring finger of hook section 52 (best seen in figure 4). The feed screw advances a pushnut 54 which has an integral pad 56 abutting the | plunger 58 of the syringe 30. The pushnut advances with each closure of the jaws.

Feed action expels a metered dab of grease containing growth-inhibiting hormone ^ from the syringe. The end portion 60 of the feed screw is blank so that when the ^ pushnut reaches this point, which is selected to coincide with the emptying of the | ^ syringe, the operator is alerted to the need to exchange syringes. Additionally the | pushnut is of the quick release type. It has a bore of epitrochoidal section one half of ? which is threaded, the opposite half being smooth. When the nut reaches the blank | part of the screw, the operator pushes the nut sideways out of engagement with the E screw and slides the nut to the start position behind the new syringe. A knurled adjuster 62 on the end of the feed screw allows the operator to prime the new syringe. A hairpin return spring 64 separates the jaws.

In another embodiment the jaw faces are modified so that only the remaining stem is fully crushed. The cane to be discarded is gripped but crushed to a lesser extent. This reduces the force required.

We have found the advantages of the above embodiment to be: 1. Accurate application of the gel to the crushed stems. 2. Economical use of the gel. | 3. Permits use of a cheap reuseable cartridge in the form of an easily obtainable ! syringe.

I | 4. Easy adaptability to powered action. t } i u 4 214608

Claims (16)

WHAT WE CLAIM IS;

1. A method of severing a plant stem and simultaneously applying a treatment liquid to the stem characterised in that as part of the cutting action the stem is urged against a surface which is at least partly covered with a treatment liquid.

2. A method as claimed in claim 1 wherein the action of urging the stem squashes the stem tissue and increases the liquid contact area.

3. A method as claimed in either claim 1 or claim 2 wherein the treatment liquid is applied to the coating surface in metered quantities.

4. A method as claimed in any one of claims 1 to 3 wherein the treatment liquid is a gel.

5. A method as claimed in claim 4 wherein the gel contains a plant growth inhibiting hormone.

6. A hand held applicator for supplying a dose of treatment liquid to a selected site on a plant comprising blade means capable of severing the plant stem and dosing means capable of applying to the severed site, a dose of treatment liquid by urging the stem against a surface at least partly covered with a treatment liquid.

7. A hand held applicator as claimed in claim 6 characterised by a jaw action which both severs and doses simultaneously.

8. A hand held applicator as claimed in claim 7 having a pair of jaws wherein one jaw acts as an anvil and the other supports a blade which closes towards the anvil -o ^ / V -6- £ r v * c-f f '1608 o

9. A hand held applicator as claimed in claim 8 wherein during the closing action the blade passes through an aperture in the anvil.

10. A hand held applicator as claimed in either claim 8 or claim 9 wherein the anvil co-operates with a corresponding anvil surface on the opposite jaw in order to exert a bruising action on the stem which is severed.

11. A hand held applicator as claimed in any one of claims 8 to 10 wherein a stop limits entry between the jaws of the stem to be severed so as to locate the stem between the blade and the anvil ensuring that the stem is subjected to severing and bruising.

12. A hand held applicator as claimed in any one of claims 8 to 11 wherein the applicator has a body equipped with one jaw and a handle pivoted to the body supporting the other jaw and the body has a breech for receiving and holding a disposable syringe.

13. A hand held applicator as claimed in claim 12 wherein the action of jaw closing exerts plunger pressure in the syringe when fitted.

14. A hand held applicator as claimed in claim 13 wherein plunger pressure is exerted by a feed screw in which the screw rotation is supplied by a jaw closing through a ratchet wheel.

15. A hand held applicator as claimed in claim 14 wherein the feed screw drives a push nut which moves the syringe plunger.

16. A hand held applicator as claimed in claim 15 wherein an adjuster on the end of the feed screw can also be used to effect rotation of the feed screw. -7- A hand held applicator as claimed in any one of claims 14 to 16 wherein the ratchet wheel is rotated by a spring finger which advances the ratchet wheel only after the stem is urged against a surface at least partly covered with a treatment liquid. A hand held applicator as claimed in any one of claims 15 to 17 wherein the end most part of the feed screw is blank allowing the push nut to signal to the operator that the syringe is empty. A hand held applicator as claimed in any one of claims 15 to 18 wherein the pushnut is a quick release nut. A hand held applicator as claimed in any one of claims 12 to 19 wherein the breech has a cavity for receiving a syringe nozzle and the cavity is the entrance to a passage in the body which opens onto the blade. A hand held applicator as claimed in claim 20 wherein the passage opens onto one face of the blade, which in use is adjacent to the location of where a bruising action on the plant stem to be retained for further growth occurs. A hand held applicator as claimed in claim 20 or 21 wherein the passage opens onto part of the anvil which is clear of the stop as claimed in claims 11 to 21. A hand held applicator as claimed in any one of claims 7 to 22 wherein the applicator is gas-powered. A method of severing and treating a plant stem substantially as herein described. 214608 A hand held applicator substantially as herein described with reference to and as illustrated in the accompanying drawings. DR. RONALD FRANCIS HENZELL. MURRAY RICHARD BRISCOE, ROBERT ALAN MILLS. BARRY ERNEST STEVENSON and RONALD GRANT PATTERSON by their Attorneys