Note: Descriptions are shown in the official language in which they were submitted.
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The present inven-tion relates to extension
handles for hedge trimmers and, more particularly, to
such extension handles adapted to facilitate the
trimming of tall hedges.
U.S. Patent No. 4,638,562 issued to Drake
on January 27, 1987, discloses an extension handle
for holding a hedge trimmer with the blade thereof in
a horizontal position and well above the head of the
operator in order that elevated or remote areas of
hedges, plants, etc., can be trimmed. The extension
handle includes a long tubular member which curves at
an upper end portion thereof in order that a motor
operated hedge trimmer may be mounted thereto so that
the blade of the trimmer extends horizontally. The
lower part of the extension handle includes a pair of
longitudinally spaced apart grips mounted thereon to
be grasped by the hands of the operator.
Using such an attachment, the full weight
of both the trimmer and the extension handle is
assumed by the arms of the operator. With part of
the extension handle being forwardly and upwardly
inclined with respect to the operator, it is also
understood that the torque applied by the trimmer to
the end of the extension handle is considerable.
Therefore, the operator using such a combination of
an extension handle and a trimmer will quickly become
tired.
U.S. Patent No. 4,483,070, issued to
Junkermann on November 20, 1984, discloses a cutter
with a frame mounted to the torso of the operator and
extending up over the back of the user and over the
top of his head. A forward end of the cutter is
joined to a top end of the frame by a cable in such a
way that the upper body of the operator assumes a
greater part of the weight of the cutter.
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Although such an arrangement has various
useful uses such as distributing most of the weight
of the cutter to the trunk of the operator, it would
however requi.re a considerably tall frame to allow
the cutter to reach high hedges. If the frame is
kept relatively short, the cable which extends
between a top part thereof and a trimmer is
necessarily also short for a trimmer positioned well
above the shoulders of the operator. In such a case
wherein the trimmer is close to the frame, a large
part of the weight of the trimmer is transferred back
to the arms of the operator. Furthermore, the top
part of the frame may become cumbersome if positioned
higher than the top part of the hedge being trimmed.
U.S. Patent No. 4,145,810, issued to
Belliston on March 27, 1979, discloses an extension
handle somewhat similar to that of above U.S. Patent
No. 4,638,562 although the extension handle of the
former is adjustable as being telescopic. However,
the length of the handle must be adjusted prior to
the use of the hedge trimmer mounted thereto. The
extension handle cannot be telescoped during use of
the hedge trimmer. Again, the full weight of the
trimmer is assumed by the arms of the operator.
It is therefore an aim of the present
invention to provide an extension handle for powered
hedge trimmers adapted to enable an operator thereof
to reach high trimming locations.
It is also an aim of the present invention
to provide such an extension handle adapted so that
most of the weight thereof and of the hedge trimmer
attached thereto is assumed by the trunk of the
operator.
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It is s-till a fur-ther aim of the present
invention to provide such an extension handle which
is adapted to allow in a simple way the hedge trimmer
to be displaced in various directions with a minimal
effort by the operator. ~ :-
A construction in accordance with the
present invention comprises an extension apparatus
for use with a powered hedge trimmer. The extension
apparatus comprises an e:Longated extension means
adapted to receive at an upper end portion thereof ;
the hedge trimmer and to be removably attached at a
lower end thereof to the trunk of an operator of the
hedge trimmer. The extension means further comprises
a handle means for displacing during use the
extension means between a retracted and an extended
position thereof.
A further construction in accordance with
the present invention comprises a powered hedge
trimmer apparatus which comprises a cutting means
driven by a motor mounted within a housing. The
housing is mounted on an upper end portion of an
elongated extension means. The elongated extension
means is adapted to be removably attached at a lower
end thereof to the trunk of an operator of the
apparatus. The extension means comprises a handle
means for displacing during use the extension means
between a retracted and an extended position thereof.
Having thus generally described the nature ~ y~
of the invention, reference will now be made to the
accompanying drawings, showing by way of illustration
a preferred embodiment thereof and in which:
Fig. 1 is an elevation of an extension
handle in accordance with the present invention `~
showing in dotted lines a hedge trimmer mounted
thereto and further showing in dotted lines a
vertical adjustment of the extension handle and of
the hedge trimmer;
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Fig. 2 is an elevation of the extension
handle of Fig. 1 adapted with a hedge trimmer and ~
showing the operation thereof; ~-
Fig. 3 is a cross-sectional side view of
the extension handle of Fig. l;
Fig. 4 is a cross-sectional side view of a
lower part of the extension handle supported by the
support gear of Fig. 2; and
Fig. 5 is a partial side view of a further ~-
extension handle in accordance with the present -
invention which includes a horizontal extension for
the hedge trimmer. -
Fig. 1 illustrates an extension handle E in
accordance with the present invention for trimming
hedges at a level exceeding the height of the
operator.
The extension handle E comprises first and -
second arms 10 and 12, respectively which form a
general inverted "V"-shaped structure. The first arm -
has a tubular body 14 including at a lower end
thereof a hand grip 16 and at an upper end thereof a
sleeve 18 welded at right angles thereto.
The second arm 12 has also a tubular body
20 which is slidably received in the sleeve 18 of the
first arm 10. A hedge trimmer mounting bracket 22 is
fixedly mounted at an upper end 24 of the tubular
body 20 of the second arm 12.
A hedge trimmer T which is shown in dotted
lines in Fig. 1 is removably attached to the mounting
bracket 22 by way of a plumbing clamp 26 embracing a
handle 28 of the trimmer T and a fork member 30, the
arms of which are fixed to the sides of a housing 32
of the trimmer T by way of screws or bolts.
A series of apertures 34 defined
diametrically through the body 20 of the second arm
12 are disposed longitudinally thereon in a spaced
apart relationship. A lower end of the sleeve 18 of
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the first arm 10 includes a pair of diametrically
opposed openings 36 defined there-through which are
aligned with selected ones of the apertures 34
through which a locking pin 38 is passed to secure
the second arm 12 in a selected position with respect
to the first arm 10. The locking pin 38 is attached
at one end of a chain 40 which is mounted at its
other end to the first arm 10 near the sleeve 18
thereof to prevent the locking pin 38 from being lost
when removed from the openings 36 and the selected
apertures 34.
The first and second arms 10 and 12 are
partly supported by a spring biased telescopic third
arm 42 which includes a first tubular section 44
having a circular end plate 46 fixedly mounted at an
upper end thereof. As best seen in Fig. 3, a load
bearing member 48 having a semi-spherical shape is
fixedly mounted on a top surface of the circular end
plate 46. A pin 50 extends longitudinally upwards
from the center of the circular end plate 46 through
the load bearing member 48 into a hole 52 defined
through a lower portion of the tubular body 14 of the
first arm 10 near the sleeve 18 thereof. The pin 50
is loosely introduced in the hole 52 in order to
allow a relative displacement therebetween so that
the first and second arms 10 and 12 can pivot about
the pin 50 while being supported by the third arm 42
as the body 14 of the arm 10 bears against the
semi-spherical load bearing member 48. The load
bearing member 48 can be made of a plastics material
or preferably of a hard rubber material to provide
smooth and quiet displacements of the first arm 10
thereon.
The third arm 42 also comprises a second
tubular section 54, the upper part of which is
slidably received in the first tubular section 44 as
seen in Fig. 3 for movement between extended and
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re-tracted positions thereof. The lower part of the : .
second tubular section 54 includes a spacer 56 which
is a short tubular section fixedly mounted to the ~.
lower end of the second tubular section 54. The.
second tubular section 54 includes at its lower end
three out-turned spokes 58. A flange 60 is mounted - .
between the lower end of the spacer 56 and the ~
out-turned spokes 58. ~: :
The upper end of the second tubular section .~
54 which is located within the first tubular section ~.
44 includes an in-turned portion 62. An elongated :
rod 64 which extends longitudinally and centrall.y -.
inside the first tubular section 44 from the bottom .
surface of the circular end plate 46 includes a
circular stopper 66 fixedly mounted at a lower end 68
of the elongated rod 64. .
From the above, it is easily understood .~
that the downwards stroke of the second tubular~:;
section 54 with respect to the first tubular section :
44 is limited by the stopper 66 abutting the
in-turned portion 62 of the second tubular section .. -~
54, as seen in Fig. 3. Also, the upwards movement of . :.
the second tubular section 54 with respect to the
first tubular section 44 is limited by the spacer 56 ~.~
abutting at its top end the lower end of the first ~ :
tubular section 44.
A relatively soft spring 70 is mounted -;
concentrically around the first and second tubular
sections 44 and 54 and around the spacer 56 between : ~ .:
the circular end plate 46 and the fl.ange 60. ~:
Now referring to Fig. 2, a support gear G
to be worn by an operator O of the extension handle E
and of the hedge trimmer T comprises a pair of~ :
shoulder straps 72 which are mounted in front of the
operator O in a support plate 74 through a pair of :~
slots 76 defined therein with the ends of the ..
shoulder straps defining loops engaged in the slots
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76. A belt 78 extends from each side of the suppork
plate 74 wlth the ends of the shoulder straps 72
located in back of the operator O defining closed
loops (not shown) around the belt 78.
Now referring to Fig. 4, a U-shaped hook 80
is fixedly mounted by way of rivets 82 to the front
of the support plate 74 of the gear G so that a free
end 84 of the hook 80 extends generally upwards in a
spaced apart relationship with respect to the support
plate 74 in order to engage in the lower open end of
the third arm 42.
From the above, it is easily understood
that most of the weight of the hedge trimmer T and of
the extension handle E is transmitted through the
third arm 42 to the support gear G and thus to the
torso of the operator O.
In order to use the extension handle E of
the present invention, the hedge trimmer T is first
mounted to the mounting bracket 22 by way of the
plumbing clamp 26 and the pair of side arms 30
thereof. It is noted that the mounting bracket 22 is
angled with respect to the first, second and third
arms 10, 12 and 42 in order that, in operation, the
hedge trimmer T mounted thereto projects frontwards
with the cutting blades 86 thereof extending
generally in a horizontal plane for trimming a top
,
portion of a hedge H, as shown in Fig. 2, a planar
and horizontal top portion. -
Now referring to Fig. 1, it is also
understood that the second arm 12 may be adjusted
with respect to the sleeve 18 of the first arm 10
with the locking pin 38 passing through the openings
36 defined in the sleeve 18 and selected ones of the
apertures 34 defined in the second arm 12.
Therefore, prior t, operation, the height of the
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hedge trimmer T may be adjusted in view of the
rela-tive height of the hedge H which is to be
trimmed.
In operation, the operator O holds with one
hand the hand grip 16 of the first arm lO and with
the other the body 20 of the second arm 12, as seen
in Fig. 2. Because of the arrangement of the rubber
washer 48 and the pin 50 with the hole 52 defined in
the first arm 10, the operator may pivot the first
and second arms 10 and 12 and thus the hedge trimmer
T with respect to the third arm 42 in a vertical
plane as indicated in Fig. 3 by arrows 88.
Furthermore, the operator O can rotate the
first and second arms 10 and 12 and the hedge trimmer
T in a substantially horizontal plane in order to
provide a sweeping movement to the cutting blades 86
of the trimmer T relative to the hedge H. The pin 50
passing through the hole 52 allows for such an
unrestricted horizontal rotation of the first and
second arms 10 and 12 and of the trimmer T by the
operator O. The weight of the first and second arms
10 and 12 and of the hedge trimmer H is considerable
enough to maintain the pin 50 in engagement in the
hole 52 as the extension handle E is being handled in
various orientations to properly trim the hedge H.
In all of the above relative displacements
of the first and second arms lO and 12 and of the
hedge trimmer T with respect to the pin 50 of the
third arm 42, the semi-spherical rubber load bearing
member ~48 provides a support and smooth guide
surface. With the hole 52 being defined closely to
the sleeve 14 and thus -to the hedge trimmer T, a
better control of the hedge trimmer is ensured as a
major part of the weight thereof is assumed by the
third arm 42 and thus by the torso of the operator O
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Z017785
with the arms of the latter exerting a minimal effort
as being mainly used to control and to position the
hedge trimmer T.
Now referring to Fig. 2, it is noted that
the spring 70 is rigid enough in order to maintain
the telescoping first and second tubular sections 44
and 54 in an at least partly extended relative
position even with the weight of the hedge trimmer T.
On the other hand, the spr:ing 70 must be relatively
soft in order to minimize the effort exerted by the
arms of the operator O when he displaces the hedge
trimmer T downwards as indicated by arrows 90 to
lower the hedge trimmer T, for instance, from a
location above the hedge H to a lower hedge engaging
position thereof, as per arrows 91. Therefore, it is
desirable to have an equilibrium between the force of
the spring 72 and the weight being assumed thereby,
which is mostly provided by the hedge trimmer T, at
an intermediate relative position of the first and
second tubular sections 44 and 54, that is between
the retracted and extended positions thereof. With
such an arrangement, the effort exerted by the arms
of the operator O to displace either upwards or
downwards the hedge trimmer T from the previously
mentioned intermediate equilibrium relative position
of the telescoping sections of the third arm 42 is
kept relatively low.
: Now referring to Fig. 5, an extension plate
92 may be provided between parts 94 and 96 forming
the mounting bracket 22 in orde;r to accommodate the
extension handle E for wider hedges.
From the foregoing, i-t is easily understood
that the combination of an extension handle E in
accordance with the present invention in combination
with a standard powered hedge trimmer T allows for a
simple and efficient control of the hedge trimmer T
when being used to trim relatively high hedges H.
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7~35
As an alternative, the arrangement of the
load bearing rubber member 48 and the pin 50 with the
hole 52 defined in the first arm 10 can be replaced
by a universal joint provided between the end plate ~
46 of the third arm 42 and the portion of the first .
arm 10 adjacent to the sleeve 18 thereof. : .
It is noted that the spring 70 which .:::
provides the bias between the tubular sections 44 and .
54 forming the third arm 42 could alternatively be
mounted inside the third arm, for instance, between
the circular end plate 46 and the in-turned portion `:
62 of the second tubular section 54.
Furthermore, gas or pneumatic pressure : .
within the third arm 42 could provide the required
bias between a piston and cylinder arrangement
similar to that proposed by the telescopic tubular
sections 44 and 54 of the illustrated embodiment.
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