WO1986002233A1

WO1986002233A1 - An improved accurate lightweight manual lawn and garden weed chipper

Info

Publication number: WO1986002233A1
Application number: PCT/AU1984/000199
Authority: WO
Inventors: Hugh Macdonald Reilly
Original assignee: Hugh Macdonald Reilly
Priority date: 1984-10-12
Filing date: 1984-10-12
Publication date: 1986-04-24
Also published as: EP0197029A1; CA1269272A; AU3553184A; NZ213754A; AU581416B2

Abstract

An improved accurate lightweight manual tool to cut suburban lawn and garden weeds efficiently and with little time and effort expended. It is like a miniature hoe half a man's height in lenght with a very thin very narrow blade (E) in length four to five times its width. The chipper's light weight is achieved with a very lightweight conduit handle (A) of any section joined at right angles by a secret joint to (D) a backing plate for the blade (E) and weighted with billet (G) to increase and change the power for weight. A thin shock absorber (H) is bolted between plate and blade by (F). The secret joint uses a steel billet (G) driven through the metal plate (D) into the conduit handle (A) thereby expanding the handle (A) against the metal collar (C). The plate (D) has a self-centring protrusion fitting into a recess in the collar (C). The permanent right angle secret locking joint uses totally prefinished components.

Description

Page ONE (1) Commencement.

AN IMPROVED ACCURATE LIGHTWEIGHT MANUAL LAWN AND GARDEN WEED CHIPPER

This invention is an improved tool for manual use by any person to cut and remove weeds from a suburban lawn and garden efficiently and with little time and effort expended.

This improved weed chipper is much lighter than the original chipper herein described, being only 61.3% of its weight, one of the major improvements made. This Improved Accurate Lightweight Manual Lawn and Garden Weed Chipper is like a miniature hoe. It is very light and has a very high power for weight ratio. This is achieved by altering the weight balance and locating the maximum weight concentration at the blade end though not in the blade itself. This has other advantages as well. Manufacturing innovations are incorporated and this makes the Chipper viable. The benefits to the user are therefore ease of use and a saving of time.

Previously the removal of weeds was done by one of the following methods:- 1. Hoe out the weed and in the process leave a large hole in the lawn or garden. Skill was needed and a lot of stamina. Due to the weight and inefficiency of a normal hoe the average gardener finds this method too tiring and seldom finishes the weeding job.

2. Many inventions have been designed and manufactured and a great amount of human effort expended to dig out the weed and its roots. Complicated systems of levers for foot and hand action have been developed. Generally the same result as the hoe was produced - a large hole and a large pile of rubbish to dispose of.

3. The average gardener having tired of methods 1 and 2. turned to chemical to kill the weeds. A lot of good lawn and prize plants are killed in the process. Refinements were to direct the chemical by various methods onto the offending weed only, using a handle. Even with the better versions the chemical leaches or touches the lawn and generally results in a series of brown spots over the lawn which take a week or two to cover in. The dying weed still has to be removed in a week or so. 4. The skilled dedicated gardener has learnt to use a sharp knife, a kneeling pad and a sore back to do the job by slicing only the crown of the weed off at ground level. This preserves the lawn or garden plants and immediately removes the weed forever.

A search of available tools in Australia and through world trade catalogues indicates that the perfect method for removing the offending weed has not yet been developed.

This Improved Accurate Lightweight Lawn and Garden Weed Chipper is used like the traditional hoe and is designed to cut the crown of the weed off cleanly at ground level without bending the user's back. Its features are :-

1. The weed is cut cleanly with a very thin blade. 2. The blade is quite narrow.

3. The power to allow this blade to cut is achieved by concentrating weight at the blade end of the chipper - and by reducing weight in the handle itself. The Power for Weight ratio is dramatically increased.

4. The concentration of weight is achieved in a locking device which allows the use of a multitude of lightweight conduit handle materials to be joined at right angles to a strong backing plate in one efficient manufacturing operation. 5. The very thin cutting steel blade which is narrow for its length is then secured by two bolts and nuts or fastening devices to the backing plate.

The solution to the problem of cutting weeds out efficiently is achieved with this lightweight chipper. It can be used either single handed or double handed by a little old lady or man without bending their back or getting tired before the job is done. They can cut the offending weed off with a short downward dropping action or by swinging the blade in a short cutting arc. There will not be a big hole to repair where the weed was. The side of the blade is a natural lightweight rake to drag back the weed that has been cut off. Additionally the chipper is a natural cultivating tool for loosening the top few centimetres of soil while the chipper is still in the hand after cutting the odd weed out.

This chipper is an improvement on the original chipper made by Mr. Cecil Carl Daley of 7 Wiangarie Street, Kyogle, N.S.W. Mr. Daley made and refined the chipper for his own use. He used it for about 30 years before he died on -+th June, 1973 at the age of 81 years. He never patented his chipper or sold it commercially. Only one or two close friends over the years were priveleged with the gift of a chipper.

Mr. Daley's hoe was made from a wooden broom handle and weighted at the blade with a short piece of waterpipe welded to a small piece of flat steel at right angles at its centre to form a Tee shape. Fastened to the flat steel Tee with two bolts and nuts was a very thin narrow cutting blade proportioned one in width to five or six in length. Both ends of the blade were sharpened, one square cut and one end pointed to a square cut one half of blade width. The blade width was wider than the flat steel Tee section allowing one sixth of blade width exposed on both sides of the flat steel.

The total effect of the tool is to provide a very light weight chipper with an extremely high power for weight action delivering a large force in a downward arc at almost right angles to the weed to be cut off at ground level. The blade was of the finest steel having been cut from an old hand saw. The blade was therefore very thin and held its edge for a long time. The wooden handle was only half a man's height in length.

Previous tools of this type relied on the weight of the handle to add to the weight of a very heavy blade which was much wider than Mr. Daley's invention. In use Mr. Daley's weed chipper was an ideal lightweight tool for a person of little strength. It delivered a sharp cutting force to exactly cut off the top of the weed - and nothing else, with very little effort. Because of its light handle and heavily weighted head, its accuracy is inherent in its design. To reach over a wide garden and deliver a blow from a foot high, cut off the weed, in the process and with a quarter turn of the wrist use the weight of the head and the protruding thin edge of the blade length to rake back the weed and level the soil in the same action is using inventiveness to produce truly efficient work with a minimum of effort.

The Improved Accurate Lightweight Lawn and Garden Weed Chipper follows on from Mr. Daley's original invention, by further refining the power for weight advantages of the chipper and fully exploiting its potential using a light and strong tubular, square or oval conduit handle, of either durable metal or plastic or fibreglass of the same length as Mr. Daley's original chipper ie. half a man's height.

The attachment of this handle at right angles to the the flat backing plate mounting for the blade comprises the second improvement made to the chipper and in effect allows this inventor to claim a patent for a new modern chipper designed for efficient manufacture and production in either a small one-at-atime machine shop or equally in a robotised mass production assembly line.

The Improved Chipper is made with the following parts:-

A. The handle H. The shock absorber

B. The handgrip

C. The collar

D. The backing plate for the blade

E. The blade F. The two bolts and nut units for attaching the replaceable blade.

G. The weighted steel billet

The Chipper is described as follows:- A. The handle is made from standard size thin wall conduit of any section from square oval or tubular stock. The wall thickness may be as thin as practical for the particular material used so that a strong lightweight durable conduit handle results. Any mass produced conduit with normal manufacturing tolerances will be suitable. The emphasis is on lightweight durable strength.

B. The handgrip is optional as the chipper will work equally well without a handgrip. When used, however, it is essential that the handgrip be as light as possible. A light weight chemically foamed conduit handgrip for both hands is ideal. A heavy moulded P.V.C. handgrip will only lessen the efficiency of the chipper.

C. The collar is made from a conduit of the same section as the handle selected so that the collar slips over the outside diameter of the handle conduit. A neat fit is not required thus allowing a stock manufactured conduit to be used of any type of material. This allows for different materials to be used for the collar, the handle, the backing plate and the billet. - This is a major feature of great importance.

The only other requirement for the collar is that the wall thickness is increased to ensure sufficient strength to resist the manufacturing process used and the in-service jarring blows of the chipper thus transferring the swing of the handle evenly through to the backing plate without failing in service by the collar splitting.

The collar is proportioned to be slightly longer than its diameter. It is manufactured by spinning in a lathe or a centralising external grip chuck and being parted off with a thin parting tool which is moved in at approximately 45° angle to the axis of the conduit stock. The one parting tool action forms the angled or rounded off end of the collar and also forms the other 45º approximate recessed end of the finished collar. This recess is very important to the manufacture of the secret joint. Refer to Figure No. 3.

D. The backing plate is required to be thin, strong and durable. Its weight is not critical but it must not bend significantly in use as it transfers the jarring action of the blade to the billet and the handle. It may be sized from standard steel, aluminium or stainless steel stock - whichever is the most cost efficient material. It may also be cast. The standard proportions of stock size metal may be used with its length in the proportion of approximately three to four times its width . The width of the backing plate is required to be approximately three quarters of the width of the blade. The backing plate has two holes spaced approximately half the width of the backing plate from each end. The diameter of the holes to be punched to suit clearance size of the securing bolts( or devices used in their place).

Through the centre of the backing plate, ie. centre of its length and its width, a hole is required to be stamped, punched or formed. This hole is to be clearance size of the outside diameter of the handle used. In the forming of this hole the material should be stretched so that a slight protrusion is formed. This protrusion is to be on one side only and should leave an equal recess on the other side. The resultant hole should match the 45° recess formed by the parting tool when manufacturing the collar. Tight manufacturing control is required in the forming of this protrusion. It can be automatically formed by a punch & die set up for normal rapid production.

E. The blade is required to be of cutting steel quality and very thin in proportion to its width and length. The width is to be approximately one and one quarter times the width of the backing plate and its length to be approximately five or four times its length, a little more or a little less.

Two holes are to be punched to match the two holes of the backing plate. The diameter of the holes is to be clearance size only of the bolts or securing devices used to secure the blade to the backing plate. The blade is to be sharpened at both ends. One end is to be sharpened the full width of the blade and the other end pointed both sides to form a sharpened square cut end approximately one half its width. The angle of the cutting edge must be suitable to the steel used in the blade.

F. The two bolts and nuts or securing devices are to clamp the blade to the backing plate and transfer the jarring force of the blade in use to the billet and handle so that no movement occurs between blade and backing plate. The securing devices are to be readily removable by the user to replace a worn blade should it be required.

G. The billet is to be of standard steel stock turned by lathe to achieve certain dimensions with a minimum of tolerance in the finished diameters selected. It could be formed by sqeezing and sizing or be cast to size. The length of the billet is to be the same for each chipper of a given production run. The weight of the finished chipper is controlled by the weight of the billet and exact production control for weight and quality control are achieved by using billets manufactured to tight tolerances. The billet is to have a known predetermined length and in section it is to have two thicknesses in its length. The smallest of these thicknesses is to be an easy slip fit into the internal diameter of the handle conduit and of a section to match the handle conduit selected, be it square, tubular or oval. The second and largest thickness of the billet is to approximately be the outside diameter or section width of the handle conduit and just smaller than the internal diameter or section width of the collar selected. The step between the two thicknesses of the billet is to be angled to approximately

45° to the axis and smoothed to form an even gradual transition from one thickness to the other. This step when the billet is in place in the manufactured chipper will be located at the end of the collar which is away from the backing plate. The thick end of the billet is to be turned or formed to a 45º angle so that a large taper is formed like the head of a counter sunk wood screw if round section is used for the handle . Refer to Figure No. 3. Assembly of the Chipper

The assembly of the chipper as a manufacturing process can be accomplished with minimal specialised equipment due to the inherent design of the component parts and is accomplished in the following manner.

The joining of the handle, collar, billet and backing plate is made by:- 1. Clamp the handle upright in a clamp to provide even pressure to the top quarter of the handle and resting the bottom end on a solid support and with the top of the handle proud of the top of the die clamp by the thickness of the backing plate plus a small predetermined amount.

2. Drop the collar into a recess so that it forms a slip fit over the exposed end of the handle and sits flush with the top of the die clamp and has its 45º recessed section upwards. The die clamp is to ensure that the collar cannot move downwards.

3. Drop the backing plate over the exposed end of the handle, ensuring that the formed protrusion is downwards and fits snug into the 45º recess of the collar.

4. Drop the billet into the conduit handle and press the billet home. In pressing the billet home the small diameter of the billet will follow down the internal conduit acting as a guide to keep the billet vertical. The gradual transition of the thickness of the billet will swage the thin wall of the handle conduit. As the billet is pressed home and as the internal diameter of the handle conduit expands, it will in turn swage slightly the thick wall collar. The resistance of this collar will be much greater and will form a joint under continual pressure. The degree of pressure exerted by the billet to cause deformation of the collar is to be pre-controlled by billet thickness to achieve minimal plastic deformation and maximum elastic deformation. This springback effect of the collar material locks the joint forever.

The handle conduit is squeezed between the billet and the collar and the balance of plastic/elastic deformation is not critical though it must be considered in relation to material fatigue at the point where the end of the billet finally finishes. The billet is pressed home in a total coldworking process and as a result the inside of the handle conduit is stretched to follow the billet. Thus seamless or seamed conduits may equally be utilised.

As the billet pushes the last few millimetres the 45º billet head will stretch the very end of the handle conduit past its point of elastic deformation and this will press hard against the recess of the backing plate. The protrusion of the backing plate will be pressed hard against the recess in the collar. The face of the collar will locate itself evenly against the face of the backing plate and square up the Tee joint thus formed automatically.

The head of the billet will form flush with the backing plate. The 45º recess formed in the collar and equally in the backing plate allows sufficient room for the displaced plastic deformed portion of the handle conduit. This results in a clean finished secret joint which requires no finishing process whatsoever. Also, the assembly requires only unskilled labour or a robotised assembly plant only. The billet having been pressed home will require an additional pressure buildup at the end to take advantage of the springback and frictional qualities of the joint to ensure a maximum locking effect of the backing plate. This can be achieved by a fast insertion of the billet using a press having a large excess of capacity beyond that normally required. Alternatively a jolt type pressing action similar to a fly press may be used, or an air actuated punch.

The chipper is removed from its die clamp with a quick release on the split die clamp. The chipper can have its blade fitted after this operation with the two securing bolts and captive nuts or similar securing devices and tightened. The handgrip can then be slipped on.

The scientific basis for the increased power for weight achieved with this chipper lies in Mass Acceleration. Reduction of weight in the handle and concentration of weight in the billet and backing plate coupled with a thin cutting steel narrow blade of little weight produces a large force at the cutting edge. The force achieved allows a person of little strength to accelerate the Mass at the end of the handle in a quick cutting action. The Mass Acceleration thus produces a force which is measured in Newtons. The length of the handle plus the length of the user's arm from wrist to elbow becomes the radius of the downward arc. The use of gravity in acceleration of the free fall of the blade is calculated as F = K x m x a where FORCE F = MASS x ACCELERATION in Knm.

This force is concentrated upon a very narrow thin cutting blade at near to right angle to the axis of the weed.

This force placed in the hands of a frail user enables the user to perform the cutting action of removing the weed and the weight balance provides the accuracy to cut only the weed and not the surrounding grass or soil thus saving the hard manual work of hoeing. The crown of the weed is cut off at ground level and the resultant hole is negligible. The chipper is then inherently provided with a flat blade which is used with the handle vertical and the hole in the lawn is tamped down with one or two dropping blows of the handle. The flat blade with the weight of the billet provides a natural tamping tool. A flat lawn where the weed was, is the result instead of the usual jagged hole with the conventional hoe. The long exposed edge of the blade becomes a natural miniature rake to remove the offending weed to a convenient pickup point near the user's feet. Thus time is saved for the user and only five minutes now and then completely eliminates the offending weed immediately.

As a major improvement, this chipper may be provided with an optional very thin synthetic rubber shock absorber "H" matching the shape of the base of the backing plate being approximately the same thickness as the blade and which is squeezed between the blade "E" and the backing plate "D" by the two bolts and nuts "F" or similar securing devices. This neutralizes the jarring force as the blade cuts the weed or strikes a solid object. It does not alter in any way the transfer of angular velocity as the chipper is swung in a downward arc. The increased benefits of ease of use and reduced fatigue for the user are thereby provided at a small cost to the manufacturer.

This tool should then move from the status of a novel tool which soon loses its appeal and is discarded to the status of a very handy, dependable, useful tool which is kept handy to the door and used regularly for very short periods. The sense of wasted mowing effort when weeds grow quite high within 2 or 3 days will be removed for the user of this chipper and will add much satisfaction to the average gardener.

It is anticipated that the demand for this improved accurate lightweight manual lawn and garden weed chipper could be very high due to its inherent features which allow the user to satisfy an almost universal human need to eliminate an annoying weed. This natural demand will attract many competitors who will attempt to void the rights and protection of this patent. For this reason an alternative to the secret joint described so far is now given as part of this specification and repeated as Claim No. 22. Likewise it is anticipated that the handle could be varied to void this patent and this variation is set out as Claim No. 23. Similarly, Claims 24 and 25 are included. Claim No. 22

An alternative to the secret locking joint is anticipated by one of the four main methods:-

22.1 Welding or moulding or casting the Tee joint or right angle joint in lieu of the secret joint so far described.

22.2 By using a weighted billet and punching over or riveting over or centre punching and thereby spreading the head of the billet to secure the backing plate ; or straight to the blade without a backing plate.

22.3 By deleting the 45º recess to the collar where it mates with the backing plate and instead square cutting the collar. This can then be used in one of two ways

22.4 The backing plate is formed without the protrusion and the opposite side of the backing plate is contersunk to allow the space for the head of the billet as described in 22.1 and 22.2 and in figure 1 showing one of two alternative joining methods in the drawings forming part of this patent. 22.5 By deleting the 45º recess to the collar where it mates with the backing plate and by square cutting the collar. The backing plate is formed with a protrusion simply pressed or punched so that the metal thickness is not deformed at the top of the protrusion and remains square cut as shown in figure 6 showing the second alternative joining method illustrated in the drawings forming part of this patent. This billet is similarly formed but with an additional recess in its section or thickness close to the billet head. The result, of this alternative joining method is that it requires much more pressure on the billet during assembly as the square cut of the collar which is held and clamped to remain solid is forced against the protrusion of the backing plate. This protrusion is thus flattened to its original flat surface. When the protrusion flattens the diameter of the hole is reduced and the circumference of the hole becomes smaller allowing the flattened protrusion to grip into the recessed thickness of the billet head. This forms a locking device on the head of the billet which will be shaped to take advantage of this locking action. In the process the handle conduit is also deformed to follow the recess in the billet head. It is anticipated that one or a combination of these variations namely 22.1, 22.2, 22.3. 22.4 and 22.5 may be used to void the protection and the rights provided by this patent and therefore these alternatives unless previously patented are claimed as a part of the property of this patent. Claim No. 23

It is anticipated that a variation to the handle conduit to further reduce its weight by reducing its diameter by a taper or a series of steps each of a lesser diameter similar to a golf club may be used to void this patent and therefore it is claimed that such a method should not be incorporated in a manual lawn and garden weed chipper without full rights and protection being afforded to this inventor by this patent. Claim No. 24

The alternative locking methods described in 22.1, 22.2, 22.3, 22.4 and 22. 5 and as referred to in Claims No. 1, 1.1 to 1.8 inclusive and Claims No. 2 to 20 inclusive and as illustrated in figure 1 and figure 6 but excluding adhesive, welding, rivetting or wedging being normal joining methodf are claimed as part of the property of this patent by this inventor or as part of the property of a separate patent at the discretion of the Commissioner of Patents. Claim No. 25

The use of the secret joint as described in Claim No. 1, 1.1 to

1.8 and Claim 2 to 19 and in figure 3 allows normal conduit stock materials with normal manufacturing tolerances to be used without special stock sizes having to be purchased and thereby incurring the associated additional costs involved. This cost saving feature forms a major claim to the property of this patent.

End of description. Claims follow.

Claims

The claims defining the invention of an improved accurate lightweight manual lawn and garden weed chipper are as follows:-Claim No. 1A lightweight manual lawn and garden weed chipper comprised of eight (8) components, two of which , 1.7 and 1.8 act as shock absorbers and are luxury components which may at the option of the inventor be used or deleted in the manufacture of the completed chipper. These components are:-

1.1 A lightweight conduit handle of any material which will in service remain straight and strong and durable and be of tubular or oval or square or any other section. The handle being in length half a man's height. The handle will be substantially as illustrated as "A" in the drawings which form part of this patent.

1.2 A very thin cutting steel blade being narrow and proportioned so that its length is four to five times its narrow width a little more or a little less and sharpened at one or both ends square to its length either full width or pointed and sharpened to one half of its width a little more or a little less. It shall have two (2) clearance size bolt holes matching the backing plate clearance size holes for securing the blade to the backing plate by two (2) bolts "F" substantially as illustrated as "E" in the drawings which form part of this patent.

1.3 A weighted backing plate for the blade designed to hold the blade solidly by bolting the blade to the backing plate with two removable bolts and nuts, or two securing devices with clearance size holes only in both backing plate and blade which prevent the holes elongating in service. The backing plate may be flat or slightly ςurved to follow the circumference of a circle having a radius the length of the handle used. The securing bolts ensure that the blade follows the curve. The backing plate to be less in width than the blade width to allow one sixth of the blade to protrude on each side of the backing plate. The backing plate to be less in length than the blade to allow one or both ends of the blade to protrude past the backing plate by an amount equal to blade width a little more or a little less, substantially as Fig.5 & Fig.3 illustrated as "D" in the drawings forming part of this patent. The backing plate "D" is to have two clearance size bolt holes matching the two clearance size holes in the blade. They shall be located approximately one half of the backing plate width from each end of the backing plate and centre of its width. The backing plate "D" is to have one hole punched, drilled or formed which is clearance size on the outside diameter or perimeter of the handle if a section other than tubular is used. This hole is to be formed to produce a protrusion on one side of the backing plate only. This protrusion is to be approximately 45º off the plane of that side of the backing plate and is to match the 45º recess in the collar "C". On the backing plate face opposite the side with the protrusion a tapered recess is formed to acceptthe tapered head of the billet "G". This hole in the backing plate, the protrusion and the tapered recess can be achieved by one punching operation and is substantially as illustrated in figure 5 and figure 3 and figure 4 of the drawings forming part of this patent. The thickness of the backing plate "D" is generally twice the thickness of the blade and is not critical unless the strength of the secret joint is weakened by using too light a thickness backing plate. 1.4 A billet of steel selected for its strength and weight and sized with a tapered head larger in section than the two stepped thicknesses of section over the length of the billet. The billet is driven or hammered or pressed through a hole in the backing plate and into the internal hole of the conduit handle so that the conduit handle is squeezed or sized or swaged outwards against the collar to form a permanent locking device which uses prefinished components of any material and allows a lightweight thin conduit to be joined at right angles or near right angles to a solid backing plate of a heavier gauge different material to form a flush face secret joint which requires no welding or adhesives or other joining method and is substantially as illustrated as part "G" in the drawings forming part of this patent. Refer to Figure 3 and Figure 5.

1.5 A collar of any material which is strong and durable and solid which has an internal hole or conduit to match the handle section and a wall thickness sufficiently strong and with sufficient elastic deformation inherent in the material that it will by springback effect form a solid permanent locking joint when the billet is driven or hammered or pressed inside the handle conduit which is therefore squeezed against the internal hole of the collar substantially as illustrated as "C" in the drawings forming part of this patent. The collar has a 45º recess at one end and a rounded 45º shoulder at the other end.

1.6 Two bolts and nuts "F" or similar securing devices to secure and bolt the blade "E" to the backing plate "D" substantially as illustrated in the drawings forming part of this patent.

1.7 A very lightweight handgrip which is optional but which if used must be selected of the very lightest weight material possible to avoid varying the power for weight ratio balance of the tool. It acts as a shock absorber for the jarring force created as the blade strikes the weed or a hard object.

1.8 An optional very thin synthetic rubber shock absorber "H" matching the shape of the base of the backing plate being approximately the same thickness as the blade and which is squeezed between the blade "E" and the backing plate "D" by the two bolts and nuts "F" or similar securing devices.

These eight (8) components two of which are optional or essential at the discretion of the inventor in the final manufactured weed chipper form the physical components of this improved manual weed chipper. Claim No.

2

The selection of the material and sizefe of each of the components backing plate, blade, billet, collar and conduit handle while infinitely variable and interchangable for type of material are required to maintain the maximum weight possible at the blade end of the handle. The lightweight handle and handgrip are required to ensure the most efficient concentration of weight possible at the blade end of the tool which ensures that maximum power for weight, angular velocity or linear speed and resultant force is achieved and delivered at the cutting edge of the thin narrow cutting blade. Claim No.

3

The length of the billet can be varied at will in manufacture to control the weight balance of the tool as described in Claim 2. Claim No .

4

The smallest thickness of the billet is a slip fit in the internal diameter of the handle conduit and allows the handle to act as a guide when pressing home the billet in the manufacturing assembly process thereby automatically providing alignment of the billet without additional machinery or care being required.

Claim No.

5

The larger thickness of the billet is sized to cause minimum plastic and maximum elastic deformation in the handle conduit as well as in the thicker wall thickness collar. The billet thickness is precalculated for each production run. Its thickness is critical to the efficiency of assembly and to the working life of the secret joint formed in the assembly of the chipper. Claim No.

6

The taper formed when the two thicknesses of the billet meet is required to be a smooth and even transition which is critical to the efficient assembly of the chipper and is an essential feature of this patent. Claim No.

7

The head of the billet nominally 30 to 45º taper is critical to the holding power of the joint and must be preformed in manufacturing the billet. It must not be punched over as a second process in the assembly of the components of the chipper. This can be done but then becomes an extra manufacturing operation. Claim No.

8

The use of the collar with the 45º recess which matches the 45º backing plate protrusion in assembly automatically produces self centring and self alignment in assembly. They also guarantee a tight fit of the collar to the backing plate which in turn adds strength and an automatic squaring up of the backing plate to the lightweight conduit handle at the Tee joint. This forms a major claim of the property of this patent. Claim No.

9

The secret locking joint formed in the manufacturing assembly process and substantially as illustrated in the drawings which form part of this patent forms a major claim of the property of this patent. Claim No.

10

The thinness and the narrowness and the configuration of the cutting steel blade forms a major claim of the property of this patent. Claim No.

11

The flat head of the billet which forms a flat flush joint thereby allowing a flat mounting of the blade is claimed as a feature of this patent. Claim No.

12 The blade width which protrudes on either side of the backing plate is claimed as a feature of this patent which allows its use as a lightweight rake once the weed is cut off. Claim No.

13

The inherent design of the secret joint which allows a mixture of infinitely variable interchangable materials for each component and allows a thin conduit handle to be joined permanently to a thick piece of material to form a Tee or right angled joint if so required. This forms a major claim of the property of this patent. Claim No .

14

The length of the smallest thickness of the billet while a slip fit in the internal conduit of the handle of the assembled chipper protrudes past the point of the shoulder of the collar. This acts to prevent leverage of the handle in service acting at the shoulder of the collar. The billet has stretched the handle internal diameter to elastic deformation and it is at this point that a potential weakness in handle strength may be created. The billet protruding past this point prevents failure in service and is a major claim of the property of this patent. Claim No.

15

The fact that the whole process of assembly of the chipper components and the secret joint is a cold working process forms a major claim of the property of this patent. Claim No.

16

The fact that the process of assembly of the secret joint allows each component to be prefinished so that once assembly of the secret joint and the chipper components is completed no further finishing process is required forms a major claim of the property of this patent. Claim No.

17

The synthetic rubber or similar material shock absorber between the flat blade and the backing plate prevents the shock resulting from the blade cutting the weed or hitting a sharp object from being transferred into the backing plate and the handle. This then acts as a one way shock absorber only and does not materially alter the transfer to the blade of the angular velocity force produced in the swing of the handle. This transfer of force from backing plate to blade by the two bolts is a solid metal to metal transfer used for maximum efficiency. The effect and use of this shock absorber forms a major claim of the property of this patent.

Claim No.

18

The inherent design of the secret locking joint dictates that the components will be self aligning and will automatically square up the Tee joint or right angle joint if used with a single ended blade in lieu of the two ended blade described. It also dictates that a machine fit will result and allows the use of totally finished components. Because of this the manufacturing assembly process may be equally completed by an unskilled person with a minimum of training using a small hand press in a one-off machine shop. Automatic quality control is inherent, with the use of quality components. Equally the process is suited to high speed machine assembly or robot type assembly controlled by a programmed computer. This is claimed by this inventor as the major claim of the property of this patent. Claim No.

19 An accurate lightweight manual lawn and garden weed chipper including Claims No. 1, 1.1 to 1.8 in whole or in part and Claims 2 to 18 inclusive in whole or in part and substantially as specified and described and drawn in the drawings forming part of this patent is claimed as part of the property of this patent by this inventor. Claim No.

20

A manual lawn and garden cutting tool substantially as described in Claims No. 1, 1.1 to 1.8 and Claims No. 2 to 19 inclusive and which uses a conduit or solid handle of any material of metal, wood, fibreglass or contrived chemically produced form of plastic handle either welded, wedged or moulded or similarly joined and or as described in Claim No. 21 is anticipated as a variation made to void the rights and protection of this patent and is therefore claimed as a part of the property of this patent. by this inventor. Claim No.

21

A manual lawn and garden cutting tool substantially as defined in Claim No. 1, 1.1 to 1.8 and Claim No. 2 to 20 inclusive which uses a lightweight wooden handle and a weighted device at the blade end and either attached to or as part of a light thin very narrow cutting blade designed to use the angular velocity and force thus produced is anticipated as a variation made to void the rights and protection of this patent and is therefore claimed as part of the property of this patent by this inventor. Claim No. 22

An alternative to the secret locking joint is anticipated by one of the four main methods:- 22.1 Welding or moulding or casting the Tee joint or right angle joint in lieu of the secret joint so far described.

22.2 By using a weighted billet and punching over or riveting over or centre punching and thereby spreading the head of the billet to secure the backing plate; or straight to the blade without a backing plate.

22.3 By deleting the 45º recess to the collar where it mates with the backing plate and instead square cutting the collar. This can then be used in one of two ways.

22.4 The backing plate is formed without the protrusion and the opposite side of the backing plate is contersunk to allow the space for the head of the billet as described in 22.1 and 22.2 and in figure 1 showing one of two alternative joining methods in the drawings forming part of this patent. 22.5 By deleting the 45º recess to the collar where it mates with the backing plate and by square cutting the collar. The backing plate is formed with a protrusion simply pressed or punched so that the metal thickness is not deformed at the top of the protrusion and remains square cut as shown in figure 6 showing the second alternative joining method illustrated in the drawings forming part of this patent. This billet is similarly formed but with an additional recess in its section or thickness close to the billet head. The result of this alternative joining method is that it requires much more pressure, on the billet during assembly as the square cut of the collar which is held and clamped to remain solid is forced against the protrusion of the backing plate. This protrusion is thus flattened to its original flat surface. When the protrusion flattens the diameter of the hole is reduced and the circumference of the hole becomes smaller allowing the flattened protrusion to grip into the recessed thickness of the billet head. This forms a locking device on the head of the billet which will be shaped to take advantage of this locking action. In the process the handle conduit is also deformed to follow the recess in the billet head. It is anticipated that one or a combination of these variations namely 22.1 , 22.2, 22.3, 22.4 and 22.5 may be used to void the protection and the rights provided by this patent and therefore these alternatives unless previously patented are claimed as a part of the property of this patent. Claim No. 23

The alternative locking methods described in 22.1, 22.2, 22.3, 22.4 and 22.5 and as referred to in Claims No. 1, 1.1 to 1.8 inclusive and Claims No. 2 to 20 inclusive and as illustrated in figure 1 and figure 6 but excluding adhesive, welding, rivetting or wedging being normal joining methods are claimed as part of the property of this patent by this inventor or as part of the property of a separate patent at the discretion of the Commissioner of Patents. Claim No. 25

The use of the secret joint as described in Claim No. 1, 1.1 to

These 25 claims are made by the inventor Mr. Hugh Macdonald Reilly

Signed:

Dated this First day of October, 1984.