Note: Descriptions are shown in the official language in which they were submitted.
CA 02404882 2002-09-25
LAWN SWEEPER
THIS APPLICATION CLAIMS PRIORITY FROM US PROVISIONAL
APPLICATION NUMBER 601324,535.
The present invention relates to a lawn sweeper.
Lawn sweepers are used to collect debris such as leafs, twigs and the
like on lawns. Sweepers commonly have a brush which rotates, rotation of the
brush picks up the debris and deposits the debris in a container or the like.
There are many variations in sweepers which commonly use motors to
rotate the brush. Sorne variations use rotation of wheels on the sweepers to
rotate
the bush. These variations of wheel driven brush commonly has an arrangement
which rotates the brush with a direct ratio of wheel rotation. Usually these
direct
ratios are used on small hand pushed or pulled sweepers but can also be found
on
larger versions. Direct ratio sweepers may not provide adequate rotation speed
of
the brush in certain situations which can inadequately sweep the lawn.
According to the present invention there is provided a sweeping
apparatus comprises:
a frame arranged for movement across a surface;
drive wheels on the frame arranged to engage the surface;
free wheels on the frame arranged to engage the surface;
a brush arrangement coupled to the frame arranged to sweep up
debris from the surface;
a catch portion on the frame for receiving the debris;
more than one gear assembly each arranged to be driven by at least
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one of the drive wheels;
a rotary brush member arranged to be rotated at a determined rate of
speed by the gear assembly for engaging debris;
a driven gear of the gear assembly coupled to and rotated by the drive
wheel;
a variable brush gear of the gear assembly;
and, a flexible drive member of each gear assembly arranged to be
driven by the drive gear and to drive the variable brush gear;
Preferably the variable brush gear has a one way bearing which
prohibits rearward rotation of the brush.
Conveniently the frame has an adjustable hifich assembly which
provides the brush with adjustable heights.
It is preferred that the brush has an axis located in front of an axis of
the wheels.
Conveniently the brush is enclosed within a pivotal front portion
pivotally coupled to the catch portion, the front portion having adjustable
heights.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which illustrate an exemplary
embodiment of the present invention:
Figure 1 is a isometric view of the sweeper.
Figure 2 is a side view of a gear assembly.
Figure 3 is a rear view of the front portion.
Figure 4 is a side elevational view of a second embodiment of the
present invention.
Figure 5 is a side elevational view of a third embodiment of the present
invention.
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DETAIL ,~ DES(,',RIPTION
Referring to the accompanying drawings, there is illustrated a lawn
sweeper 1. The sweeper is arranged to collect and contain debris on lawns or
other
similar surfaces such as leaves, twigs and the like. The sweeper has a front
pick up
portion 3 and a rear collection portion 5. The front portion has a brush
arrangement
7 which is arranged to pick up the debris and throw the debris into a
collector 9 of
the rear portion.
The front portion has a housing 11 having an open bottom portion 13
and an open rear portion 15. The open bottom portion is arranged to allow a
rotary
brush 17 to engage the ground surface and the open rear portion provides an
aperture 19 through which the debris enters the collector. The front portion
is
supported above the ground surface by a pair of drive wheels 21. The drive
wheels
are rotatably mounted to each side of the front portion. Each wheel has an
independent mounting shaft 23 which are coaxial.
The front portion has a hitch arrangement 25 which is arranged for
attaching the sweeper to a hitch on a tractor or the like. The hitch
arrangement has
an elongate pivotal member 27 extending across a front end 29 of the front
portion
which is pivotally mounted to respective sides 31 of the front portion by
mount arms
33. The mount arms extend rearwards from respective outer ends of the pivotal
member and are pivotally coupled to a respective side of the front portion.
The
pivotal mounting of the pivotal member allows the member to be moved upwards
and downwards in front of the sweeper. A hitch arm 35 extends forwards from
the
pivotal member. The hitch arm has a coupler 37 arranged to be coupled to a
hitch
on a tractor or the like. Extending upward from the pivotal member is an
elongate
adjustment bar 37. The adjustment bar has a plurality of notches 39 along its
length.
A support member 41 is mounted to the front of the front portion and is
arranged to
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engage the adjustment bar such that the bar can be positioned at a desired
height.
The adjustment bar is locked at the notches to the support member which
provides
adjustability to the front portion of the sweeper. The front portion is
pivotally
mounted to the rear portion and the wheels are mounted at a rear end of the
front
portion such that the front portion can be raised and lowered by pivoting the
front
portion about an axis of the pivotal mount and the wheels and can be locked in
the
adjusted position by the adjustment bar on the hitch member.
The brush on the front end is mounted on a elongate shaft 43 which
has an axis parallel to the axis of the wheel shafts. The axis of the brush is
located
in front of the wheel shafts such that pivotal movement of the front end
raises and
lowers the brush. The vertical movement of the front end moves the brush shaft
about the axis of the wheel shafts.
The brush is driven by a pair of gear assemblies 45. Each gear
assembly is located on a respective side of the front portion and is driven by
a
respective wheel. Each gear assembly has a drive gear 47 mounted on each wheel
shaft. A idler gear 49 is located generally above the drive gear. A second
idler gear
51 is located ahead and above the first idler gear. A brush gear 53 is
positioned
between the idler gears above the first idler gear and below the second idler
gear. A
chain 54 wraps around a portion of the driven gear up to and around the first
idler
gear, across to and around the second idler gear, up and around the brush gear
and
down to the driven gear. The chain has a tensioning device 56 which provides
the
chain with adjustable tension on the gears. The brush gear is mounted to the
shaft
of the brush such that the brush is rotated by the rotation of each wheel
driving each
respective gear assembly. The gear assembly provides the brush with a variable
rotation speed. The speed of brush rotation is directly related to the ratio
of teeth on
each gear. The rotation speed is set to rotate between 30 and 80 rotations per
100
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ft. The rotation speed of the brush is varied in order to provide enough
rotation
thereof to pick up debris and to eliminate the force needed to rotate the
wheels. The
wheels will lock or skid if the brush is set to rotate above an estimated 80
rotation
per 100 ft and the brush will not pick up a sufficient amount of debris if the
brush
rotates below and estimated 30 rotations per 100 ft.
The brush gear is mounted to the brush shaft on a respective side
thereof by a one way shaft bearing 55. The bearing is arranged such if the
sweeper
is moved in a reverse direction the brush does not rotate. The bearing allows
the
brush to rotate at a desired speed while the sweeper is turning while being
towed.
Turning of the sweeper causes the inside wheel to rotate slower than the
outside
wheel which causes the brush shaft to rotate at a high rate than the inner
gear
assembly. The gear assembly provides the brush with consistent rotation speed
such that debris while the sweeper is being turned is not missed and had to be
passed again in a straight line.
The rear portion of the sweeper has a dumping arrangement which
consists of a pivotal rear gate 57 that allows the debris to be unloaded when
tilted.
Castor wheels 59 are mounted at rear corners of the rear portion for support.
As
best illustrated in figure 4 and 5, the dumping arrangement is pivotally
mounted at a
rear end 59A to a frame 60A of the sweeper such that a front end 59B adjacent
the
front portion at the open rear portion can be raised. Raising of the front end
tilts the
collection portion on the pivotal mount at the frame such that the front end
is raised
above the rear end. The front end is raised by an actuator 60B and powered by
a
battery.
The gate on the rear end of the collector is pivoted at a top end and a
cable 64 extends from the top end of the gate which is connected to the frame.
As
the front end of the collector is raised the cable pulls downwards on a lever
66
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connected to the gate such that the gate is opened.
The brush is a conventional street sweeping brush wrapped around a
tubular member 61 surrounding and mounted to the brush shaft. The brush is
enclosed within the front portion such that the debris is directed through the
aperture
into the collector. The front portion or shroud, of the sweeper, as best shown
in
figure 1, is arranged to provide a vacuum so that the debris is thrown clearly
into the
collector. The shroud has an open bottom portion 81 in which the brush extends
to
engage the ground. A front end 83 of the shroud is designed to be
substantially 1"
from the brush and opens up at a top end 85 to be substantially 4" from the
brush.
Figure 5 illustrates a second embodiment of the present invention.
The second embodiment has a power take off drive arrangement (PTO) 71 which
replaces the drive arrangement of the embodiment shown in figures 1 through 3.
The PTO arrangement is arranged such that the gear assembly is driven by the
tractor pulling the sweeper. The PTO provides a user with a selection of brush
speeds for different applications.
Figure 4 illustrates a variation of the PTO drive arrangement which has
an adjustable height assembly 73 such that the height of the brush relative to
the
ground can be adjusted.
While one embodiment of the present invention has been described in
the foregoing, it is to be understood that other embodiments are possible
within the
scope of the invention. The invention is to be considered limited solely by
the scope
of the appended claims.