Note: Descriptions are shown in the official language in which they were submitted.
~2ti~ ~7Z
_ IMPROV~D ACCURATE LIG~TWEIG~T MANUAL LAWN AND GARDE~
WEED C~IPPER
This invention is an improved tool for manual usè by any person
to cut and remove weeds from a 6uburban lawn and garder efficiently
and with little time and effort expended.
The impr~ved weed chipper of the present invention is much lighter than the
original chipper herein described, being only 61.3% of its weight, one of
the major imprcvements made.
~0 Thi6 i~proved accurate lightweight manual lawn and garden weed
chipper is like a miniature hoe. It i6 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
advantage6 as well. Nanufacturing innovations are incorporated
and this ~akes the chiE~per viable. The benefits to the user
are therefore ea6e of use and a 6aving of time.
Previou61y the removal of weeds was done by one of the following
methods:-
1. 20e out the weed and in the process lea~e 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 tbe weed and
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its roots. Complicated systems of lever6 for foot and hand
action have been developed. Generally the same re6ult 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 chemicals to kill the weeds. A lot of good
lawn and prize plants are killed in the process. Refinements
were to direct the chemicals by varicus methods onto the o~fending
weed only, using a handle.
~ven with the better ~ersions 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.
~he dying wsed 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 throu~h world
20 trade catalogues i~dicates that the perfect method for removing
the offending weed has not yet been developed.
This improved accurate lightweight lawn and garden weed
chipper i~ used like the traditional hoe and i6 designed to cut
the crow~ 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.
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2. The blade is quite narrow.
3. The power to allow this blade to cut i6 achieved byconcentrating weight at the blade end of the chipper - ard by
reducing weight in the handle itself. The power for weight
ratio is dramatically increa~ed.
4. The concentration of weight is achieved in a locking
device ~hich ~lows the use of a multitude of lightweiBht
conduit handle materials to be joined at right ~gles to a
strong backin& plate in one efficient manufacturing operation.
lQ. 5. The very thin cutting steel blade which i6 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 weed6 out
efficiently is achieved with this lightweight chipper. It can
be u~ed either single handed or double handed by a little old
lady or man without bending their back or getting tired before
the job i~ done. They can cut the offending weed off with a
6hort downward dropping action or by swinging the blade in a
short cutting arc. There will not be a big hole to repair where
20.the weed wa6. The side of the blade is a natural lightweight
rake to drag back the weed that has been cut off. Addition~lly
the chipper i6 a natural cultivating tool for loosening the
top few centimetre6 of 60il while the chipper is still in the
hand after cutting the odd weed out.
This chipper i8 an improvement on the origin~l chipper
made by Mr. Cecil Carl Daley of 7 Wiangarie Street, Kyogle, N.S.W.
~Z~9~ t2
Mr. Daley made and refined the chipper for his own use. ~e used
it for about 30 years before he died on 4th June, 1973 at the
age of 81 years. ~e never patented his chipper or sold it
commercially. Only one or two clo6e friends over the years were
privileged with the gift of a chipper.
Mr. D~ley 16 hoe was made from a wooden broom haGdle and
weighted at the blade with a short piece of waterpipe welded
to a small piece of flat steel at right a~gles at its centre
to form a Tee shape. ~astened 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. ~oth ends of the blade
were sharpened, one 6quare cut and one end pointed to a square
cut one half of the blade width. The blade which was wider than the
flat steel Tee section,allowing one siXth of the blade width exposed
on both sidec of the flat 6teel.
The total effect of the tool is to provide a very light
weight chipper with an e~tremely high power for weight action
delivering a large force in a downward arc at almost right
angle6 to the weed to be cut off at grou~d level. The blade was
of the finest steel having been cut from an old hand saw. The
blade wa6 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 thi6 type relied on the weight of the
handle to add to the weight of a very hea~y 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
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strength. It del~vered a sharp cutting force to e~actly cut off
the top of the weed - and nothing el6e, with ver~ little effort.
Because of its light ha~dle and heavily weighted head, its
accuracy is inherent in its de6ign. lo reach over a wide garden
and deliver a blow from a foot high, cut off the weed in the
proce~s and with a quarter turn of the wrist uRe the weight of
the head and the protruding thin ed3e of the blade len~th to
rake back the ~eed and le~el the 60il in the same action is
usi~g in~enti~eness to produce truly efficient work with a
minimum of effort.
The improved accurate lightweight lawn and garden weed
chipper of the present invention 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
flat backing plate mounting for the blade comprises the second
improvement made to the chipper and in effect provides a new
modern chipper designed for efficient manufacture and production
in either a small one-at-a time machine shop or equally in a
robotised mass production assembly line.
The present invention, in one aspect, resides in a gardening
implement of the type having a lightweight tubular handle
provided with a hand grip at its upper end and a mounting assembly
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at its lower end for a chipping blade~characterised in that said
mounting assembly includes:- an elongated plate-like mounting
member having a mounting aperture extending therethrough; a
billet insert having an elongate body part which extends through
said mounting aperture and into said tubular handle and an
enlarged head part disposed externally of said handle which engages
said mounting member about the periphery of said mounting
aperture, and an external retaining collar supported about the
lower end of said handle and retained in an elastically expanded
state about said lower end by said billet insert.
In another aspect the present invention resides in a
gardening implement as defined above wherein the mounting member
supports a chipping blade detachably secured thereto. Preferably
the chipping blade is a narrow rectangular blade which extends
outwardly beyond said mounting member and wherein said mounting
member is provided with fixing apertures spaced from said mount-
ing aperture whereby said blade may be bolted to said mounting
member.
In still another aspect, the present invention resides
in a gardening implement as defined above wherein there is
provided a resilient mounting pad adapted to be interposed
between said mounting member and said chipping blade.
~ he present invention, in yet another, preferred aspect,
resides in a gardening implement as defined above, wherein the
enlarged head part is a tapered annular collar and wherein said
mounting aperture is correspondingly tapered and receives said
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tapered annular collar.The present invention further provides a gardening
implement as defined above wherein said body part is stepped
and includes an inner end portion which slides freely within
said tubular handle and an intermediate portion which retains
said collar.
The present invention, in a further aspect, resides
in a method of securing a mounting member to one end of a
lightweight tubular handle of a gardening implement as defined
above, which method includes:
(a) forming a retaining collar to fit neatly about
the lower end of said handle;
(b) placing said retaining collar on said lower end;
(c) forming an aperture in said mounting member
whereby the latter may pass over said lower end and
abut the annular end face of said retaining collar;
(d) forming an elongate billet having:- an inner end
which fits neatly within said tube; an intermediate
portion adapted to fit through said mounting aperture
and to enlarge said lower end when forced therein, and
a head portior which will not pass through said mounting
aperture;
(e) placing said mounting member over said lower end
for support about said mounting aperture by said
retaining collar; and
(f) forcing said billet into said lower end until said
head portion clamps said mounting member to said lower
end.
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BRIEF DESCRIPTION OF THE DRAWINGS
Figure la is an exploded perspective view of the
manual weed chipper of the present invention, the
optional handgrip being omitted, showing the actual
size components prior to assembly.
Figure lb is a diagram of the manual weed chipper
one half of a person's height in length.
Figure lc illustrates the actual size components
of the manual weed chipper in assembled form with the
handle and handgrip length reduced by portions thereof
being shown as broken away.
Figure 2 is a perspective view of the manual weed
chipper, including the handgrip, in assembled form.
Figure 3a illustrates the method of joining of
components of the manual weed chipper of the present
invention.
Figure 3b (heavy circle) is an enlarged view of a
portion of what is shown in Figure 3a, and more specifically
is a magnified sectional view of the right angle joint.
Figure 3c (light circle) is an enlarged view of
another portion of what is shown in Figure 3a, and more
specifically is a magnified view of the top shoulder of the
collar C, with the handle A being forced outwards by the
billet G.
Figure 4a is a bottom view of the assembled weed
chipper as seen by a user.
Figure 4b is a side view of the lower portion of
the assembled weed chipper as seen by a user.
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Figure 4c is a plan view of chipping blade E which
is detachably secured to the manual weed chipper of the
present invention.
Figure 5 is an illustration of another embodiment
of the present invention, showing the lower portion of the
assembled weed chipper.
Figure 6, is a magnified sectional view of an
alternative joint which may be used in the manufacture of
the manual weed chipper of this invention.
Figure 7 is a magnified sectional view of a further
alternative joint which may be used in the manufacture of
the manual weed chipper of the present invention.
The improved chipper of the present invention is
made with the following parts:
A. The handle
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. 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
H. The shock absorber
The chipper of the present invention 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. In length the handle is half a man's height.
B. The handgrip is optional as the chipper will workequally well without a handgrip. When used, however, it is
essential that the handgrip be as light as possible. A light
20 weight chemically foamed conduit handgrip for both hands is
ideal. A heavy moulded PVC handg~ip 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
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~lZ~92'72
be used for the collar, the handle, the backing plate and the
billet. ~his is a maJor feature of gre~t importance.
The o~ly other requirement for the collar is that the
wall thickness i6 increased to ens~re sufficient 6trength to
resist the manufacturing process u6ed and tbe in-ser~ice
jarring blows of tbe chipper,thus transferring the ~wing of the
handle e~enly through to the backing plate without failing
in oervice by the collar 6plitting.
The collar is proportioned to be slightly longer than
~0 its diameter. It i~ 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 approsimately a 45 angle
to the a~is of the conduit stock. The one parting tool action
forms the angled or rounded off end of the collar and al60
forms the other approximately 45 bevelled end of the finished
collar. This bevelling is very important in effecting joining
of the oomponents. See FIGS. 3a-3c of the drawings.
D. The backing plate i6 required to be thin, 6trong and
durable. It6 wei pt is not critical but it must not bend
6ignificantly in use as it transfers the jarring action of the
blade to the billet and the handle. It may be sized from standard
steel, alumi~`um or stainle66 steel 6tock - whiche~er is the
most cost efficient material. It may also be cast. The
standard proportions of 6tock size metal may be used with its
length in the proportion of appro~imately three to four`times
it6 ~idth. ~he width of the backing plate is required to be
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ap~roximately 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
lG hole the material should be stretched so that a slight
protrusion is formed. This protrusion is to be one side
only and should leave an equal recess on the other side.
The resultant hole should match the 4~ bevel 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 production. The backing plate may be flat or
slightly curved to follow the circumference of a circle having a
radius the length of the handle used. The securing bolts ensure
20 that the blade follows the curve.
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 width 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
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sharpened at both ends. One end is to be sharpened the full
width of the blade and the other end pointed both aide6 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.
~ . The two bolts and nuts or securing devices are to
clamp the blade to the backing plate and tran6fer the jarrinE
force of the blade in u6e to the billet and handle 60 that
no movement occurs be ~ the blade and bac3cing plate. The
aecuring device6 are to be readily removable by the user
to replace a worn blade should it be required.
G. ~he billet is to be of standard steel 6tock turned
by lathe to achieve certain dimen6ions with a minimum of
tolerance in the finished diameters selected. It could be
formed by squeezing and slzing or be cast to size. The length
of the billet i6 to be the sa~e 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 usin~
billets manufactured to tight tolerances. ~he billet is to
have a k~own predetermined length and in section it is to
have tWD thicknes6es in its length. ~he 6mPlle6t of the6e
thicknes6es is to be an easy slip fit into the internal
diameter of the handle conduit and of a sectio~ to match the
handle conduit selected, be it square, tubular or oval. ~he
second and largest thicknes6 of the billet is to approximately
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be the outside diameter or section width of the handle
conduit and just smaller than the internal diameter or
6ection 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 a even gradual
transition fro- one thickness to the other. ~his 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. ~he thick end of the bil~et is to be turned or
$or~ed to a 45 a~gle 60 that a large taper i6 formed like
the head of a counter sunk wood screw if a round section is used
for the handle. Reference is made to FIGS. 3a-3c of the drawincs.
As6embly of the Chipper
The as6embly of the chipper a~ 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.
~he joining of the handle, collar, billet and backing plate
is made by:-
1. Clamp the handle upright in a cla~p to provide even
pressure to the top quarter of the handle and resting the
bottom end OD 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 plu6 a small predetermined amount.
2. Drop the collar such that it forms a
slip fit over the exposed end of the handle and 6its nush
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with the top of the die'clamp and has it5 45 bevelled
section upwards. The die clamp is to ensure that the collar
cannot move downwards.
~ . Drop the backing plate o~er the expo~ed end of the
hsndle, ensuring that the formed protrusion is downwards
and fits snug into the 45 bevelled end of the collar.
4. Drop the billet into the conduit handle and press
the billet home. In preR~ing the billet home the 6mall
diameter of the billet will follow down the internal conduit
acting as a guide to keep the billet ~ertical. The gradual
tra~ition of the thickness of the billet will swage the thin
wall of the handle conduit. As the billet i~ pre6sed home and
a6 the internal diameter of the handle conduit expand6, 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 pre6sure. The degree of pressure exerted by
the billet to cause deformation of the collar i6 to be
pre-controlled by billet thickness to achieve minimal plastic
deformation and maximum elastic deformation. This springback
effect of the collar material permanently locks the joint.
The handle conduit i6 squeezed between the billet
and the collar and the balance of plastic/elastic deformation
i6 not critical though it must be con~idered in relation
to material fatigue at the point where the end of the bi-llet
finally fini6hes. The billet is pre6sed home in a total
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coldworking process and as a re~ult the inside of the handle
conduit is 6tretched to follow the billet. Thus seamles6
or seamed conduit6 may equally be utili6ed.
As the billet pushes the la6t few millimetres the 45 tapered
billet head will stretch the very end of the handle conduit
past its point of elastic deformation and this will press
hard against the reces6 of the backi~ plate. ~he pr~trusio~
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 ~ee joint thus formed automatically.
The head of the billet will form n ush with tbe backing
plate. The 45 bevelled end formed in the oollar and equally in
the backing plate Al lows sufficient room for the displaced
pla6tic deformed portion of the handle conduit. Thi6 result6
in a clean firished joint which requires no finishing
proces6 whatsoever. A1BO~ the assembly require6 only
un6killed labour or a robotised a6sembly plant only. ~he
billet having been pres6ed home will require an additional
pressure buildup at the end to take advantage of the
~prin6back and frictional qualities of the joint to ensure
a maximum locking effect of the backing plate. Thi6 ca~ 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
dmilar to a fly pres6 may be u6ed, or a~ air actuated
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punch.
The chipper i6 removed from it~ die clamp with a quickrelease on the split die clamp. The chipper can have its
blade fitted after thi~ operation with the two securing bolt6
and captive nuts or 6imilar securing devices and tightened.
The handgrip can then be 61ipped on.
The 6cientific basis for the increased power for weight
achieved with thi6 chipper lie6 in mass acceleration.
Beduction of weight in the handle and concentration of weight
10 in the billet and backing plate coupled with a thin cutting
~teel ~arrow blade of little weight produces a large force
at the cutting edge. The force achieved allows a person of
little strength to accelerate the m~ss at the end of the handle
in a quick cutting action. The mass acceleration thu6 protuces
a force which i6 mea6ured in newtans~ The length of the handle
plus the length of the user' 6 arm from wrist to elbow becomes
the radiu6 of the downward arc. The use of gravity in
acceleration of the free fall of the blade i6 calculated as
F - K x m x a
where PORCE F - N~SS x ACCELERATION in Knm.
This force is concentrated upon a very narrow thin cutting
blade at near to a right ansle to the axis of the weed,
This force placed in the hand6 of a frail user enable6
the user to perform the cutting action of removing the weed
and the weight balance pro~ide6 the accuracy to cut only the
weed and not the surrounding gras6 or soil thu6 saving the
hard manual work of hoeing. The crown of the weed i~ cut off
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at ground level and the re5ult~nt hole i~ neglieible. Theohipper i~ the~ inhere~tly provided with a flht blade whlch i6
uaed with the handle vertical and the hole in the lawn i6
tsmpsd do~n with one o~ two dropping blow~ of the handle. The
fl~t blade with the weight of the billet provido6 a natur~l
t~mpin~ tool. A fl~t l~wn where the weed wa~, i& the r~ult
in~t-ad of the u~ual ~agged hole mad~ w1th th~ conventlona~ hoe
The long expo~ed edge of the blade b~comes h ~tur~l miniature
rake to remove the offending ~eod to a oonvenient pickup point
10 ~aar the u~er 1 8 feet. Thu& time i~ ~avod for the user and
o~ly fiv0 minutes now snd than completely oliminate~ tho
offending weed immediately.
A3 c major improvement, this chipper may be p-o~ided with
an option~l vory thin oynthetic rubber ohock ab~orber "B"
matching the ~h~pe of the ba~e of the backing plate being
approximately the same thickness B5 the blade and which io
equoezed betwcen the blade '~" And the backirg plate "D" by the
two bolto aLd nut~ '~" or eimilar socuring devices. This
~outr~li7~o the ~rring forco ae the blade cut~ the weed or
20 gtrike~ a ~olid ob~oct. It does not ~lter ln any w~y the
trAn~fer of ~gular Yolocity as the chippor i~ ~vung in a
downw~rd arc~ Tho increaaed benefits of eaoe of use and
reducod fatlgue for the u~er are thereby pro~ided at A umall
oo-t to th- manufaoturer.
Thi~ tool should then move from the gtatug of a no~el tool
which ~oon loee6 it~ appesl and io discarded to the ~tatus of a
~e~y handy, dopendable, useful tool which i6 kept handy to the
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door and used regularly for very short periods. Thesense 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.
Alternative embodiments of the invention described
so far are now given as part of this specification.
Alternatives to the joint described hereinabove may
be provided by one of the following five methods:-
tl) Welding or moulding or casting the Tee jOillt or
right angle joint in lieu of the joint so far
described.
(2) By using a weighted billet and punching over or
riveting over or centre punching and thereby
2J spreading the head of the billet to secure the
backing plate; or straight to the blade without a
backing plate.
(3) By deleting the 45 bevel 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.
(4) The backing plate is formed without the protrusion
and the opposite side of the backing plate is
countersunk to allow the space for the head of the
3~ billet as described in (l) and (2) and in Figure 6
showing one of two alternative joining methods in
the drawings forming part of this patent.
(5) By deleting the 45 bevel 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
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7 showing the second alternative joining method
illustrated in the drawings forming part of this
patent. This billet is similarly formed but with sn
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
bscking 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. Any one or a
combination of these variations, namely (1), (2),
(3), (4) and (5),may be used.
The handle conduit may be varied 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. It is my intention that such variation be
incorporated within the scope of the present invention as
claimed.
The alternative locking methods described in (1),
(2),(3), (4) and (5) as illustrated in Figure 6 and
Figure 7 but excluding adhesive, welding, rivetting or
wedging being normal joining methods sre intended to be
encompassed by the present invention as disclosed and
clsimed in this specification.
The use of the joint as illustrated in Figure 3a
allows normal conduit stock materials with normal
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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 is an important feature of the present invention.
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