Note: Descriptions are shown in the official language in which they were submitted.
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Floor cleaning apparatus
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a floor cleaning apparatus according to the preamble
of claim 1
and to a method for cleaning a floor using the same according to the preamble
of claim
27.
2. Description of the Related Art
An apparatus for cleaning a floor surface is known from US 5,901,410
WINDMEISSER.
This known cleaning apparatus is suitable for wet cleaning and comprises a
front
suction unit in front of the brushing means and a rear suction unit behind the
brushing
means. Fresh cleaning liquid is supplied to the brushing means from a first
tank in either
travel direction. The front suction unit and the rear suction unit both extend
parallel to
the brushing means and are both connected to a second tank. The cleaning
liquid is
sucked up by the rear suction unit when the cleaning apparatus is moved in
forward
travel direction and sucked up by the front suction unit when the cleaning
apparatus is
moved in a backward travel direction. A drawback of this known device is that
both
suction units are always active in either travel direction of the cleaning
apparatus but
only one of the front and rear suction units is used to suck up the cleaning
liquid applied
to the floor via the brushing means.
BRIEF SUMMARY OF THE INVENTION
It is an object of the invention to provide a floor cleaning apparatus which
has a front
and a rear suction unit and which permits to either increase the vacuum
applied to a
suction unit or to increase the suction volume flow rate without changing the
vacuum
turbine power.
The invention solves the posed problem with a floor cleaning apparatus
comprising the
features of claim 1 as well as with a method for cleaning a floor using the
same and
comprising the features of claim 27.
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The advantages of the floor cleaning apparatus according to the invention are
essentially to be seen in the facts that:
- during a movement of the cleaning apparatus in the forward travel
direction the
front suction channel is closed and the entire suction performance of the
vacuum
turbine is concentrated on the rear suction unit. Due to the closed front
suction
channel the suction volume flow rate is reduced and thus an increased vacuum
in the rear suction channel can be achieved when the cleaning apparatus is
moved in forward travel direction;
- during a movement of the cleaning apparatus in the backward travel
direction the
front suction unit opens so that the front suction unit and the rear suction
unit
actively suck up cleaning liquid resulting in a combined high suction volume
flow
rate; and
- a vacuum turbine can therefore be used which has a constant suction power
when either both suction units are simultaneously active thus allowing a high
suction volume flow rate or when the rear suction unit is active only thus
allowing
a high vacuum.
In a special embodiment the closing member closes the front suction channel
when the
cleaning apparatus is moved in a forward travel direction.
In another embodiment the closing member opens the front suction channel when
the
cleaning apparatus is moved in a backward travel direction. Due to this
configuration the
front suction channel can be opened or closed by simply changing the travel
direction of
the cleaning apparatus.
In a further embodiment the rear suction unit comprises a rear suction channel
which
remains open during both movements of the cleaning apparatus in the forward
and
backward travel direction. This configuration permits the advantage that
because the
rear suction channel is open in either travel direction the suction volume
flow rate of the
cleaning unit can simply be increased by moving the cleaning apparatus in the
backward travel direction.
In a further embodiment the front suction channel comprises a suction opening
which is
open towards a floor to be cleaned over the entire length of the front suction
unit and
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the closing member closes the suction opening of the front suction channel
when the
cleaning apparatus is moved in a forward travel direction and opens the
suction opening
when the cleaning apparatus is moved in a backward travel direction. By this
means a
simple configuration of the closing member is achievable.
In another embodiment the front suction channel comprises a suction opening
which is
open towards a floor to be cleaned and the closing member comprises a lip with
a front
section which frontally limits the suction opening along its entire length and
a rear
section which rearwardly limits the suction opening along its entire length.
By this
means the advantage can be achieved that the front section of the lip can be
used to
close or open the suction opening of the front suction channel.
Preferably, the closing member is actuated by frictional forces acting on the
front
section of the lip due to a sliding movement of the same on a floor to be
cleaned when
the cleaning apparatus is moved in the forward travel direction of the
cleaning
apparatus or in the backward travel direction of the cleaning apparatus. The
advantage
of this configuration can be seen therein that the closing member can be
actuated
without any auxiliary drive or device and must not be separately actuated by
the
operator. Preferably, the lip is made of a resilient material permitting the
advantage that
the front section of the lip is biased into its initial configuration where
the front suction
opening is opened.
In a further embodiment the front section of the lip has a vertical height HF
and the rear
section of the lip has a vertical height HR and wherein HF is larger than HR
so that the
front section is bendable across the suction opening. By this means the
advantage can
be achieved that when the cleaning apparatus is moved in the forward travel
direction
the front section of the lip is bent under the rear section so that
consequently the suction
slot is closed and only minimal or no suction is effected by the front suction
unit. When
the cleaning apparatus is moved in the backward travel direction the front
section of the
lip initially contacts the floor to be cleaned and is pushed oppositely to the
backward
travel direction, i.e. towards the front end of the cleaning apparatus so that
the suction
slot of the front suction unit is opened and the front suction bar fulfills in
this condition
the function of a standard suction bar.
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Preferably, the front section of the lip is bendable as far as a portion of
the front section
extends below the rear section so that the suction opening of the front
suction channel
can be completely closed.
In a further embodiment the rear suction unit comprises a rear suction channel
and both
of the front suction channel and the rear suction channel are connected to a
manifold so
as to be in fluid connection with a single vacuum turbine. The advantage of
this
configuration is that the cleaning apparatus can be operated with a single
vacuum
turbine. Preferably, the cleaning unit comprises a first electric driving
motor for the
vacuum turbine and at least a second electric driving motor for the at least
one brush.
In again a further embodiment the front suction unit and the rear suction unit
extend
transverse to the forward and backward travel direction of the cleaning
apparatus.
Preferably, when measured orthogonal to a vertical middle plane of the
cleaning
apparatus the front suction unit and the rear suction unit each have a length
which is
equal to or larger than a dimension of the at least one brush orthogonal to
the vertical
middle plane.
In another embodiment the cleaning apparatus further comprises a brush housing
and
the rear suction unit is attached to the brush housing by means of a resilient
connecting
device allowing the rear suction unit to move laterally with respect to the
chassis against
an elastic resistance provided by the resilient connecting device.
Preferably, the resilient connecting device comprises an elastic connector
which forms a
pivot joint affixed to the brush housing by means of a fastener. Preferably,
the pivot joint
has an axis of rotation extending essentially vertically.
In another embodiment the rear suction unit comprises a curved suction bar,
preferably
an essentially elliptically curved suction bar.
In a further embodiment the resilient connecting device comprises an elongated
bracket
having a first end affixed to the rear suction unit and a second end attached
to the brush
housing by means of an elastic connector. Preferably, the elongated bracket is
biased in
a position of rest by means of the elastic connector wherein when in the
position of rest
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the elongated bracket extends along a forward or backward travel direction of
the
cleaning apparatus.
In a further embodiment the at least one brush is rotatable about a rotational
axis
extending essentially vertically.
In another embodiment the cleaning apparatus further comprises a handlebar
which is
suitable to move the cleaning apparatus on a floor to be cleaned.
Preferably, the rear suction unit is arranged in front of the rear wheels.
This
configuration permits the advantage that when moving the cleaning apparatus in
a
forward travel direction the rear wheels move outside of the wet area of the
floor to be
cleaned.
In a further embodiment the cleaning apparatus further comprises a first tank
which is
attached to the chassis and which is configured as a receptacle with its
smallest
dimension X extending vertically with respect to the forward and backward
travel
direction of the cleaning apparatus. Preferably, the cleaning apparatus
further
comprises a second tank which is arranged in the rear portion of the cleaning
apparatus
and which is configured as a receptacle having a smallest dimension Z in the
forward or
rearward travel direction of the cleaning apparatus.
In another embodiment the cleaning apparatus can further comprise an elongated
member which extends from the rear end of the chassis, wherein the second tank
is
attachable to the elongated member. Preferably, one end of the elongated
member is
rotatably affixed to the chassis by means of a hinge. This configuration
permits the
advantage that the elongated member with the second tank attached thereto can
be
backwardly rotated about the rotational axis of the hinge so as to permit to
clean the
floor under a table.
A BRIEF DESCRIPTION OF THE DRAWINGS
A special embodiment of the invention will be described in the following by
way of
example and with reference to the accompanying drawings in which:
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Fig. 1 illustrates a side view of an embodiment of the floor cleaning
apparatus according
to the invention;
Fig. 2 illustrates an exploded perspective view of the front portion of the
embodiment of
the floor cleaning apparatus according to the invention shown in fig. 1;
Fig. 3 illustrates a sectional view of the brush housing along the vertical
middle plane;
Fig. 4 illustrates a magnified sectional view of detail B in fig. 3; and
Fig. 5 illustrates a side view of an embodiment of the floor cleaning
apparatus according
to the invention shown in fig. 1 with the second tank additionally illustrated
in a vertical
and backward tilted position.
DETAILED DESCRIPTION OF THE INVENTION
Although the invention is described in conjunction with a specific embodiment
thereof, it
is evident that many alternatives, modifications and variations will be
apparent to those
skilled in the art. Accordingly, it is intended to embrace all such
alternatives,
modifications and variations that fall within the spirit and broad scope of
the appended
claims.
All publications, patents and patent applications mentioned in this
specification are
herein incorporated in their entirety by reference into the specification, to
the same
extent as if each individual publication, patent or patent application was
specifically and
individually indicated to be incorporated herein by reference. In addition,
citation or
identification of any reference in this application shall not be construed as
an admission
that such reference is available as prior art to the present invention. To the
extent that
section headings are used, they should not be construed as necessarily
limiting. The
terms "comprises", "comprising", "includes", "including", "having" and their
conjugates
mean "including but not limited to". This term encompasses the terms
"consisting of"
and "consisting essentially of".
The terms "front", "rear", "forward" and "backward" are understood as being
directed to
a "forward travel direction" of the cleaning apparatus, i.e. a movement of the
cleaning
apparatus by manually pushing the handlebar towards the front portion of the
cleaning
apparatus so that the same moves on the floor to be cleaned with the front
portion
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ahead. The term "backward travel direction" is meant to be the opposite travel
direction
by pulling the handlebar so that the cleaning apparatus moves on the floor
with the rear
portion ahead. The wording "lateral" or in "a lateral direction" is understood
as located
beside or extending in a cross direction with respect to the forward and
backward travel
direction. Furthermore, the terms "lower side of the chassis", "upper side of
the chassis",
"above", "below", "vertical" and "horizontal" are referenced to the cleaning
apparatus
positioned on the floor to be cleaned.
The term "chassis" is understood as being a framework which supports and/or
holds in
position the various parts of the cleaning apparatus and to which the
handlebar is
affixed and the rear wheels are rotatably attached.
As used herein, the singular form "a", "an" and "the" include plural
references unless the
context clearly dictates otherwise. For example, the term "a brush" or "at
least one
brush" may include a plurality of brushes.
Throughout this application, various embodiments of this invention may be
presented in
a range format. It should be understood that the description in range format
is merely for
convenience and brevity and should not be construed as an inflexible
limitation on the
scope of the invention. Accordingly, the description of a range should be
considered to
have specifically disclosed all the possible subranges as well as individual
numerical
values within that range. For example, description of a range such as from 1
to 6 should
be considered to have specifically disclosed subranges such as from 1 to 3,
from 1 to 4,
from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual
numbers
within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless
of the
breadth of the range.
Whenever a numerical range is indicated herein, it is meant to include any
cited
numeral (fractional or integral) within the indicated range. The phrases
"ranging/ranges
between" a first indicate number and a second indicate number and
"ranging/ranges
from" a first indicate number "to" a second indicate number are used herein
interchangeably and are meant to include the first and second indicated
numbers and
all the fractional and integral numerals therebetween.
It is appreciated that certain features of the invention, which are, for
clarity, described in
the context of separate embodiments, may also be provided in combination in a
single
embodiment Conversely, various features of the invention, which are, for
brevity,
described in the context of a single embodiment, may also be provided
separately or in
any suitable subcombination or as suitable in any other described embodiment
of the
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invention. Certain features described in the context of various embodiments
are not to
be considered essential features of those embodiments, unless the embodiment
is
inoperative without those elements. As used herein the term "method" refers to
manners, means, techniques and procedures for accomplishing a given task
including,
but not limited to, those manners, means, techniques and procedures either
known to,
or readily developed from known manners, means, techniques and procedures by
practitioners of mechanical engineering.
The word "exemplary" is used herein to mean "serving as an example, instance
or
illustration". Any embodiment described as "exemplary" is not necessarily to
be
construed as preferred or advantageous over other embodiments and/or to
exclude the
incorporation of features from other embodiments.
The word "optionally" is used herein to mean "is provided in some embodiments
and not
provided in other embodiments". Any particular embodiment of the invention may
include a plurality of "optional" features unless such features conflict.
Figs. 1 to 4 illustrate an embodiment of the cleaning apparatus 1 for wet
cleaning of a
floor 12. The cleaning apparatus 1 essentially comprises a front portion 16, a
rear
portion 17 with two lateral rear wheels 3, a chassis 2 and a cleaning unit 4
attached to
the chassis 2. Exemplarily, the cleaning apparatus 1 can be provided with a
handlebar 6
which is suitable to move the cleaning apparatus 1 on a floor 12 to be
cleaned.
Alternatively, the cleaning apparatus 1 can be driven by a motor and
controlled by the
operator by means of control means attached to the cleaning apparatus 1 or can
be
controlled by a remote control. The handlebar 6 can be attached to the chassis
2 by
means of an essentially vertically extending elongated member 9, e.g. a post
so that the
handlebar 6 permits to move the cleaning apparatus 1 manually in a forward and
a
backward travel direction. In various embodiments of the cleaning apparatus 1
according to the invention the cleaning unit 4 can comprise one or more
brushes 20.
Exemplarily, but not limiting, the embodiment of the cleaning apparatus 1
illustrated in
fig. 1 to 5 is provided with a cleaning unit 4 comprising two brushes 20. The
two brushes
20 are rotatably attached to a brush housing 22. The brushes 20 are rotatable
about a
rotational axis 21 each. The brushes 20 can for example, but not limited to,
be arranged
with their rotational axes 21 extending vertically on opposite sides of the
vertical middle
plane 18 and essentially vertically to the forward and backward travel
direction of the
cleaning apparatus. Alternatively, the one or more brushes 20 can be arranged
with
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their rotational axes 21 extending horizontally in a lateral direction of the
cleaning
apparatus 1.
Further, the cleaning unit 4 can comprise a first tank 15, a second tank 13,
preferably
two rotatable brushes 20 and a suction device 25 permitting to suck up the
dirty
cleaning liquid. The first tank 15 is used for fresh water supply while the
second tank 13
is used as a recovery water tank into which the dirty cleaning water sucked up
from the
floor 12 can be delivered by means of the suction device 25 via the flexible
tube 33.
Furthermore, the cleaning unit 4 can comprise a first electric driving motor
(not shown)
for driving the vacuum turbine 5 and a second and third electric driving motor
(not
shown) each for driving one of the two brushes 20. The cleaning apparatus 1
can be
provided with a battery 35, preferably a lithium-ion battery to supply the
electric driving
motors with electric energy. The two brushes 20 can rotate with opposite
senses of
rotation.
Preferably, the first tank 15 is configured as a fresh water tank and the
second tank 13
is configured as a recovery water tank. Furthermore, the first tank 15 can be
detachably
affixed to the chassis 2 by means of a quick fixing device and the second tank
13 can
be detachably affixed to the elongated member 9 by means of a quick fixing
device. The
first tank 15, i.e. the fresh water tank is connected to a piping and/or
flexible tube
system (not shown) so as to allow water to flow from the first tank 15 via a
nozzle 45
(fig. 2) to each one brush 20. The brushes 20 are arranged in front of the
rear wheels 3
in the front portion 16 of the cleaning apparatus 1 and protrude from the
lower side 19 of
the chassis 2 so as to be contactable with the floor 12 to be cleaned. The
brush housing
22 can be attached to the chassis 2 at the lower side 19 thereof.
The suction device 25 can comprise a front suction unit 8 arranged in front of
the
brushes 20, a rear suction unit 7 arranged rearward of the at least one brush
20 and a
vacuum turbine 5 which is operatively connected to the front suction unit 8
and to the
rear suction unit 7. Each of the front and rear suction units 8, 7 can be
attached to the
brush housing 22. The front suction unit 8 can be configured as a linear
suction bar and
can comprises a front suction channel 29 and a closing mechanism 26 which
closes the
front suction channel 29 when the cleaning apparatus 1 is moved in a forward
travel
direction. The two brushes 20, the front suction unit 8 and the rear suction
unit 7 define
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a floor contact region 44 for contacting the floor 12 to be cleaned when the
cleaning
apparatus 1 is in a working position as illustrated in fig. 1. The closing
mechanism 26
opens the front suction channel 29 when the cleaning apparatus 1 is tilted
backwards so
as to raise the floor contact region 44 relative to the rear wheels 3. Apart
from this the
closing mechanism 26 opens the front suction channel 29 when the cleaning
apparatus
1 is moved in a backward travel direction. Furthermore, the rear suction unit
7
comprises a rear suction channel 30 which is open during movement of the
cleaning
apparatus 1 in the forward and the backward travel directions. By this means
the
suction volume flow rate of the cleaning unit 4 can simply be increased by
moving the
cleaning apparatus 1 in the backward travel direction while the vacuum applied
to the
rear suction unit 7 can be increased by moving the cleaning apparatus 1 in the
forward
travel direction in which the front suction unit 8 is closed. The front
suction channel 29
comprises a suction opening 24 which is open towards a floor 12 to be cleaned
over the
entire length of the front suction unit 8. The closing mechanism 26 can be
configured in
such a way that it closes the suction opening 24 of the front suction channel
29 when
the cleaning apparatus 1 is moved in a forward travel direction and opens the
suction
opening 24 when the cleaning apparatus 1 is moved in a backward travel
direction. For
this purpose the closing mechanism 26 can comprise a lip 41 which can be
configured
as a plastic or rubber gasket, wherein the lip 41 can have a front section 27
(figs. 3 and
4) which frontally limits the suction opening 24 along its entire length and a
rear section
28 which rearwardly limits the suction opening 24 along its entire length.
When the
cleaning apparatus 1 is moved forward or backward in its working position with
the floor
contact region 44 contacting the floor 12 to be cleaned the closing mechanism
26 is
actuated, i.e. closed and/or opened by frictional forces acting on the front
section 27 of
the lip 41 due to a sliding movement of the front section 27 on the floor 12
to be cleaned
when the cleaning apparatus is moved in its forward travel direction, i.e.
with the front
portion 16 of the chassis 2 ahead or in the backward travel direction, i.e.
with the rear
portion 17 of the chassis 2 ahead.
Preferably, the front section 27 and the rear section 28 of the lip 41 are
made of a
resilient material. By this means the front section 27 of the lip 41 can be
biased into its
initial configuration where the front suction opening 24 is opened when the
floor contact
region 44 including the lip 41 is lifted from the floor 12 to be cleaned. The
front section
27 of the lip 41 has a vertical height HF protruding from the bottom of the
brush housing
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22 and the rear section 28 of the lip 41 has a vertical height HR protruding
from the
bottom of the brush housing 22. Thereby, HF is larger than HR so that the
front section
27 of the lip 41 is bendable across the suction opening 24 of the front
suction channel
29. Upon moving the cleaning apparatus 1 in the forward travel direction the
front
section 27 of the lip 41 is bent under the rear section 28 and the suction
slot 24 is
closed. Upon moving the cleaning apparatus 1 in the backward travel direction
the front
section 27 of the lip 41 is pushed towards the front end 38 of the cleaning
apparatus 1
so that the suction slot 24 of the front suction unit 8 is opened. Preferably,
the front
section 27 of the lip 41 is bendable as far as a portion of the front section
27 extends
below the rear section 28 of the lip 41 so as to completely close the suction
opening 24
of the front suction channel 29. The front suction unit 8 and the rear suction
unit 7
extend transverse to the forward and backward travel direction of the cleaning
apparatus 1 and - when measured orthogonal to a vertical middle plane 18 of
the
chassis 2 - the front suction unit 8 and the rear suction unit 7 each have a
length which
is equal to or larger than a dimension of the two brushes 20 orthogonal to the
vertical
middle plane 18. Further, the rear suction unit 7 comprises a rear suction
channel 30
and both of the front suction channel 29 and the rear suction channel 30 are
connected
to a manifold 31 so as to be in fluid connection with a single vacuum turbine
5. The
vacuum turbine 5 is configured to create sufficient vacuum for active suction
of the
cleaning liquid in a forward and backward movement of the cleaning apparatus
1. The
cleaning apparatus 1 is configured so that in a forward movement the entire
vacuum
performance is concentrated on the rear suction device 7. This due to the fact
that
during a forward movement the front section 27 of the lip 41 prevents any
airflow at the
front suction device 8. During backward movement the front suction unit 8
allows airflow
and actively suck up of cleaning liquid. During backward movement both suction
units
front 8 and back 7 actively suck up cleaning liquids.
As illustrated in figs. 1 - 3 the suction device 25 comprises a rear suction
unit 7 which is
attached to the brush housing 22 by means of a resilient connecting device 10
permitting the rear suction unit 7 to move laterally with respect to the
chassis 2 against
an elastic resistance provided by the resilient connecting device 10. The
resilient
connecting device 10 can comprise an elongated bracket 46 having a first end
49
affixed to the rear suction unit 7 and a second end 50 attached to the brush
housing 22
by means of an elastic connector 11. The first end 49 of the elongated bracket
46 can
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be Y-shaped to provide a rigid fixation of the rear suction unit 7. The
elastic connector
11 preferably forms a pivot joint affixed to the brush housing 22 by means of
a fastener
47, wherein the pivot joint has an axis 42 of rotation extending vertically
with respect to
a forward or backward travel direction of the cleaning apparatus 1. The
elastic
connector 11 can consist of a plastic or rubber. The outer periphery of the
elastic
connector 11 can be polygonally configured to prevent rotation between the
elastic
connector 11 and the elongated bracket 46 or can be rotationally stable
affixed to the
elongated bracket 46 by an adhesive or any other means known to the skilled
person.
By means of the elastic connector lithe elongated bracket 46 is biased in a
position of
rest in which the elongated bracket 46 extends along a forward or backward
travel
direction of the cleaning apparatus 1. The rear suction unit 7 can be
rearwardly spaced
apart from the brush housing 22 by a spacing of minimum 30%, preferably
minimum
35% of the diameter of one of the brushes 20. Due to the fact that the
elongated bracket
46 is elastically attached to the brush housing 22 the rear suction unit 7 can
follow the
path of the brushes 20 when the cleaning apparatus 1 is moved along a curved
path or
can be elastically pressed against a vertical wall when the cleaning apparatus
1 is
moved along this wall closely enough to elastically press the rear suction
unit 7 out of its
position of rest against the elastic resistance provided by the elastic
connector 11.
Preferably, the rear suction unit 7 comprises a curved suction bar extending
on an arc
around a rear portion of the two brushes 20 so that the brushes are partially
encircled.
In embodiments of the cleaning apparatus 1 with two brushes the rear suction
unit 7 is
preferably configured as an essentially elliptically curved suction bar to fit
better around
a portion of the rear periphery of the pair of brushes 20. Further, each a
stopper pin 43
can be mounted on the top side of the brush housing 22 on either side of the
vertical
middle plane 18 so as to limit the swiveling motion of the bracket 11.
Preferably, the
stopper pins 43 limit the swiveling motion of the bracket 11 within an angle
of maximum
60 , preferably of maximum 45 and of minimum 30 , preferably of minimum
350.
As best seen in fig. 5 the first tank 15 is attachable to the chassis 2 and is
configured as
a receptacle with its smallest dimension X extending vertically with respect
to the
forward and backward travel direction of the cleaning apparatus 1. Further,
the cleaning
apparatus 1 can comprise an elongated member 9 which extends from the end of
the
chassis 2 to the handlebar 6, wherein the second tank 13 is attachable to the
elongated
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member 9. The second tank 13 has a smallest dimension Z extending essentially
perpendicular to a plane defined by the elongated member 9 and the handlebar
6. One
end of the elongated member 9 can be rotatably affixed to the chassis 2 by
means of a
hinge 39 having a rotational axis 40 extending in the lateral direction of the
cleaning
apparatus 1. By this means the elongated member 9 with the second tank 13
attached
thereto can be backwardly rotated about the rotational axis 40 of the hinge so
as to
permit to clean the floor 12 under a table or under a bench. The elongated
member 9
can be adjustable and loosenably securable at a selected angle between -900
and +900
with respect to a horizontal plane. Thus, the elongated member 9 with the
second tank
13 attached thereto can be rotated from an essentially vertical position which
is suitable
to put aside the cleaning apparatus 1 on a minimum space to a horizontal
position
permitting a reduced overall height of the complete cleaning apparatus 1. The
brushes
20 and the rear suction unit 7 define a floor contact region 44 when the
cleaning
apparatus 1 is in a working position and the first tank 15 can extend
vertically with
respect to the floor contact region 44 to a level of maximum 40 cm, preferably
maximum
35 cm. In a preferred embodiment each of the first and second tanks 15, 13 can
have a
volume of typically 9 liters. In one embodiment the cleaning apparatus 1 can
additionally
comprise a mechanical actuation device (not shown), preferably a lever hoist
to rotate
the elongated member 9 about the rotational axis 40 of the hinge 39. By this
means the
weight of the second tank 13 must not be manually lifted or lowered by the
user during
an adjustment of the elongated member 9 with the second tank 13 attached
thereto
from a vertical position to a horizontal position or vice versa. The weight of
the second
tank 13 can be lifted or lowered by means of the mechanical actuation device.
Preferably, the first tank 15 longitudinally extends over the front and the
rear portion 16,
17 of the cleaning apparatus 1 so as to have a maximum horizontal cross-
sectional
area. The first tank 15 can taper towards the front end 38 of the chassis 2 to
achieve a
low front portion 16 of the cleaning apparatus 1 suitable to clean the floor
12 under e.g.
a bench.
While various descriptions of the present invention are described above, it
should be
understood that the various features can be used singly or in any combination
thereof.
The scope of the present invention is accordingly defined as set forth in the
appended
claims.
