U.S. patent application number 15/102017 was filed with the patent office on 2016-10-20 for autononmous cleaner.
This patent application is currently assigned to Aktiebolaget Electrolux. The applicant listed for this patent is Aktiebolaget Electrolux. Invention is credited to Magnus Wennerstrom.
Application Number | 20160302637 15/102017 |
Document ID | / |
Family ID | 49949640 |
Filed Date | 2016-10-20 |
United States Patent
Application |
20160302637 |
Kind Code |
A1 |
Wennerstrom; Magnus |
October 20, 2016 |
AUTONONMOUS CLEANER
Abstract
An autonomous cleaner having: a cleaner body in which a cavity
is defined; and a dust container removably fitted in the cavity,
the dust container having an air and debris inlet, and an air
outlet for admitting an air flow through the dust container. The
dust container has a dust compartment for the debris, and the ratio
between the dust compartment volume and the cleaner body volume is
within the range 0.1 to 0.2.
Inventors: |
Wennerstrom; Magnus;
(Stockholm, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Aktiebolaget Electrolux |
Stockholm |
|
SE |
|
|
Assignee: |
Aktiebolaget Electrolux
Stockholm
SE
|
Family ID: |
49949640 |
Appl. No.: |
15/102017 |
Filed: |
December 20, 2013 |
PCT Filed: |
December 20, 2013 |
PCT NO: |
PCT/EP2013/077657 |
371 Date: |
June 6, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A47L 9/1409 20130101;
A47L 2201/00 20130101; A47L 2201/04 20130101; A47L 11/4041
20130101; A47L 11/24 20130101; A47L 11/4011 20130101; A47L 11/4013
20130101 |
International
Class: |
A47L 11/24 20060101
A47L011/24; A47L 11/40 20060101 A47L011/40 |
Claims
1. An autonomous cleaner comprising: a cleaner body in which a
cavity is defined; and a dust container removably fitted in the
cavity, the dust container comprising an air and debris inlet, an
air outlet for admitting an air flow through the dust container,
the dust container comprises a dust compartment for the debris,
wherein the ratio between the dust compartment volume and the
cleaner body volume is within the range 0.1 to 0.2.
2. The autonomous cleaner according to claim 1, wherein the dust
container furthermore comprises a container wall and a filter
arranged in the dust container, wherein the dust compartment within
the dust container is defined by the container wall and the
filter.
3. The autonomous cleaner according to claim 1, wherein the cleaner
body is surrounded by a casing, and the volume of the cleaner body
defined by the casing is within the range 4 to 7 liters.
4. The autonomous cleaner according to claim 1, wherein the dust
container comprises a surface arranged to constitute a part of the
cleaner casing.
5. The autonomous cleaner according to anyone of claim 1, wherein
the air and debris inlet is arranged in a first side of the dust
container and the outlet is arranged in a second side of the dust
container, the filter is arranged to extend across the entire dust
container between the air and debris inlet and the outlet and the
volume of the dust compartment on the air and debris inlet side of
the filter is at least 0.6 liters.
6. The autonomous cleaner according to claim 5, wherein the cleaner
body has a lower side intended to be arranged towards a floor
surface, an upper side in which the cavity is defined and a forward
and an aft end.
7. The autonomous cleaner according to claim 6, wherein an
elongated brush roll with a first end and a second end is arranged
in a recess in the lower side of the cleaner body, the brush roll
is extending substantially transverse to a longitudinal axis of the
cleaner.
8. The autonomous cleaner according to claim 7, furthermore
comprising a brush roll engine adapted rotate the brush roll, the
engine is arranged close to the longitudinal axis behind the brush
roll and an elongated drive shaft extending from the engine towards
one end of the brush roll where a drive transmission is
arranged.
9. The autonomous cleaner according to claim 8, furthermore
comprising two drive units each comprising a wheel and a wheel
engine for powering the wheel, the drive units are arranged behind
the brush roll adjacent to the first end and the second end of the
brush roll and the brush roll engine is arranged between the two
drive units.
10. The autonomous cleaner according to claim 9, wherein the wheel
engines of the drive units are electrical engines powered by at
least two battery packs arranged separately from each other within
the cleaner body.
11. The autonomous cleaner according to claim 9, wherein each drive
unit furthermore comprises a wheel suspension extending in forward
direction from a wheel shaft.
12. The autonomous cleaner according to claim 6, wherein the
cleaner body has a substantially triangular shape with a forward
end and an aft end, the forward end being wider than the aft end,
and the brush roll is arranged in the forward end and the dust
container in a center of the cleaner body between the forward end
and the aft end.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an autonomous cleaner.
BACKGROUND OF THE INVENTION
[0002] In order to facilitate the work related to vacuum cleaning
of floor areas in different types of building structures,
autonomous vacuum cleaners have been available on the market for
some time. These autonomous cleaners automatically move in
different directions over the floor to clean the floor area without
human involvement. The cleaner is either moving randomly or
according to a predetermined pattern over the floor until a
navigation system detects an obstacle or the cleaner hit some
obstacle and turn. Consequently, the size and design of the cleaner
is important factors to ensure that the cleaner is able to access
as large area as possible of the floor since a cleaner with a
limited height and width will be able to access areas under and
around furniture, or in close corners more easily.
[0003] Autonomous cleaners have a cleaner body which comprises the
different components of the cleaner, and wheels supporting the body
to make it possible for the cleaner to move over the floor surface.
In the cleaner body electrical motors are arranged together with at
least two wheels for powering the cleaner. Particles such as dust,
sand etc are collected from the floor surface by a brush roll and
lead via a passage adjacent to the roll to a dust container
arranged within the body. In order to further improve the cleaning
result the roll could be combined with a fan powered by an electric
motor to generate a flow of air through the passage to suck the
particles into the passage and the dust container.
[0004] In order to make the cleaner work as intended, and ensure a
good cleaning result, several components need to be arranged in the
cleaner body. This is however contradictable to the desired small
outer dimensions of the cleaner body to make it possible for the
cleaner to access as large area as possible of the floor surface.
The design of each of the components, as well as the interior
design of the cleaner is consequently extremely important to ensure
the desired function of the different components, the desired
limited size of the cleaner body and the possibility to clean as
large areas as possible without requiring frequent emptying of the
dust container.
[0005] There are a number of autonomous cleaners disclosed in the
prior art. One example of a cleaner is illustrated in WO
2013/105431. The disclosed cleaner has a substantially circular
cleaner body comprising the different components of the cleaner. As
can be seen in the figures a number of different components are
fitted within the cleaner body which in combination with the
desired small outer size of the cleaner makes the room for the
different components limited. The limited space within the cleaner
body has some severe drawbacks on the disclosed cleaner. One of
them is that the dust container has a very small volume. The small
volume results in that the container must be emptied more
frequently to ensure the desired cleaning result which is
devastating since the container must be emptied manually.
Furthermore the removal and fitting of the dust container in the
cleaner body is complicated du to the complex design of the dust
container and the surrounding structures in the cleaner body.
[0006] There is consequently a need for an improved dust container
and an autonomous cleaner design that reduces the drawback
described above.
SUMMARY OF THE INVENTION
[0007] The present invention, defined in the appended claims,
relates to an autonomous cleaner that to at least some extent
fulfils the needs defined above.
[0008] The autonomous cleaner according to the invention comprises:
[0009] a cleaner body in which a cavity is defined; and [0010] a
dust container removably fitted in the cavity, said dust container
comprising an air and debris inlet, an air outlet for admitting an
air flow through the dust container, said dust container comprises
a dust compartment for the debris, wherein the ratio between the
dust compartment volume and the cleaner body volume is within the
range 0.1 to 0.2.
[0011] The dust compartment volume is defined as the volume within
the dust container usable for particles, debris and dust, and the
volume of the cleaner body the volume within the cleaner body with
the volume of the dust container included in the cleaner body
volume.
[0012] The cleaner according to the invention provides an efficient
autonomous cleaner that is able to cover large floor areas without
requiring emptying of the dust container since the volume of the
dust container in relation to the volume within the cleaner body is
larger than in known cleaners. The increased dust container volume
is a result of extensive work to optimize the different components
arranged in the cleaner body and the internal configuration and
layout of the different components required to ensure that the
autonomous cleaner work as intended.
[0013] In one embodiment of the autonomous cleaner, the dust
container furthermore comprises a container wall and a filter
arranged in the dust container, wherein the dust compartment within
the dust container is defined by the container wall and the filter.
The filter, together with the container wall, defines the dust
compartment, i.e. the dust compartment usable for debris received
in the dust container.
[0014] In one embodiment of the autonomous cleaner, the cleaner
body is surrounded by a casing and the volume of the cleaner body
defined by the casing is within the range 4 to 6 litres. The casing
protects the different components arranged in the cleaner body and
the specified volume ensures a cleaner body with limited outer
dimensions which makes it easier for the cleaner to clean areas
that otherwise would have been difficult to access.
[0015] In one embodiment of the autonomous cleaner, the dust
container comprises a surface arranged to constitute a part of the
cleaner casing to reduce the number of different components and/or
different constructional elements within the cleaner body and
thereby make it possible to increase the dust container volume
within the cleaner body.
[0016] In one embodiment of the autonomous cleaner, the inlet is
arranged in a first side and the outlet is arranged in a second
side of the dust container, said filter is arranged to extend
across the entire dust container between the inlet and the outlet
and the volume of the dust compartment on the inlet side of the
filter is at least 0,6 liters. The defined container design with
the filter in the dust container is favourable since the flow of
air through the dust container will extend through the filter. This
embodiment furthermore makes it possible to arrange a filter with
large filter area such that the flow of air must pass through the
filter.
[0017] In one embodiment of the autonomous cleaner, the cleaner
body has a lower side intended to be arranged towards a floor
surface, an upper side in which the cavity is defined and a forward
and an aft end.
[0018] In one embodiment of the autonomous cleaner, an elongated
brush roll with a first and a second end is arranged in a recess in
the lower side of the cleaner body, said brush roll is extending
substantially transverse to a longitudinal direction of the
cleaner.
[0019] One embodiment of the autonomous cleaner furthermore
comprises a brush roll engine adapted rotate the brush roll, the
engine is arranged close to the longitudinal axis behind the brush
roll and an elongated drive shaft extending from the engine towards
one end of the brush roll where a drive transmission is arranged.
The defined position and design of the brush roll engine and the
drive shaft makes it possible to arrange the engine in a position
within the cleaner body that makes it possible to increase the
volume of the dust container since the engine is arranged in front
of the dust container close to the bottom structure of the cleaner
body.
[0020] One embodiment of the autonomous cleaner comprises two drive
units each comprising a wheel and an engine powering the wheel,
said drive units are arranged behind the brush roll adjacent to the
first and second end of the brush roll and said brush engine is
arranged between the first and second drive unit. The use of two
separately arranged drive units facilitates the installation since
each wheel has its dedicated small electrical engine arranged in
direct relation to respective wheel.
[0021] In one embodiment of the autonomous cleaner, the engines of
the drive units are electrical engines powered by at least two
battery packs arranged separately within the cleaner body.
Electrical engines are small, reliable and efficient. Furthermore,
the use of two battery packs reduces the overall size of each
battery pack which makes it easier to fit the battery packs within
the cleaner body and ensures a reliable powering of the cleaner
since each battery pack will be able to power the cleaner
individually for a period of time.
[0022] In one embodiment of the autonomous cleaner, the drive units
furthermore comprise a wheel suspension extending in forward
direction from the wheel shaft. The wheel suspension makes it
easier for the cleaner to access areas where the floor structure is
rough and obstacles are arranged on the floor surface.
[0023] In one embodiment of the autonomous cleaner, the cleaner
body has a substantially triangular shape with a wider forward than
aft end. The brush roll is arranged in the forward end and the dust
container in the centre of the cleaner body. The triangular shape
improves the possibilities for the cleaner to access areas that
otherwise would have been difficult to reach.
[0024] The different embodiment described above may of course be
combined and modified in different ways without departing from the
scope of the invention that will be described more in detail in the
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] One embodiment of the dust container and an autonomous
cleaner are illustrated in the appended figures.
[0026] FIG. 1 discloses a perspective view of an autonomous
cleaner.
[0027] FIG. 2 discloses the autonomous cleaner in a cross sectional
view through the longitudinal direction of the autonomous
cleaner.
[0028] FIG. 3 discloses a perspective view of the dust
container
[0029] FIG. 4 discloses a perspective view of the interior of an
autonomous cleaner from above.
[0030] FIG. 5 illustrates an exploded view of different components
of the autonomous cleaner.
DETAILED DESCRIPTION
[0031] An autonomous cleaner 10 is illustrated in perspective in
FIG. 1. The cleaner has a cleaner body 11 in which all cleaner
components are arranged. The cleaner body is enclosed by a cleaner
casing 12 that surrounds the different components arranged within
the cleaner body. The cleaner casing 12 is designed to both make
room for the required components enclosed by the casing, and to
give the cleaner the desired attractive appearance. The shape and
colour could be modified in several different ways.
[0032] The illustrated cleaner 10 has a forward end 13 and an aft
end 14, and a longitudinal axis L extending through the centre of
the cleaner body. The cleaner casing 12 has and front side 15 that
is slightly curved while the width of the cleaner is reduced
towards the rounded aft end 14 resulting in a substantially
triangular shape with rounded corners. The shape of the cleaner,
with rounded corners, is important to ensure that the cleaner can
access and turn in narrow passages or floor areas.
[0033] In the front side 15 of the cleaner 10, means 16 for
navigation of the cleaner are arranged. Furthermore, the forward
part of the cleaner casing 12 is formed as a front section 17
structurally separated from the rest of the cleaner casing. The
front section 17 is designed as a bumper with detecting means that
indicate if the cleaner hit an obstacle. The means 16 for
navigation, and the detection means are connected to a control unit
arranged within the cleaner body 11. The control unit, in the
illustrated embodiment of the cleaner the control unit comprises a
printed circuit board 80 extending substantially horizontally in
the forward end of the cleaner body in order to process
information, control the manoeuvring of the autonomous cleaner and
the different functions of the cleaner. The casing 12 furthermore
comprises a substantially flat top side 18.
[0034] In FIG. 2 a cross sectional view though the longitudinal
axis L of the cleaner 10 is illustrated and in FIG. 4 a sections of
the casing has been excluded to more clearly illustrate the
interior of the autonomous cleaner and the different components
fitted in the cleaner body. FIG. 5 illustrates an exploded view of
the autonomous cleaner. In the forward end 13 of the cleaner body,
an elongated brush roll 19 is arranged in a corresponding recess in
the lower side of the autonomous cleaner. The brush roll 19 has a
substantially circular cross section and extends across
substantially the entire forward end of the cleaner perpendicular
to the longitudinal axis L to cover as wide floor area as possible
when the cleaner is moving over the floor surface. The brush roll
is provided with at least one brush 20 and/or elastic rib 21 that
extend along the roll 22 either substantially straight along the
brush roll, or helically around the brush roll. The brush roll in
the forward end of the cleaner body is intended to lift and collect
particles from the floor surface and transports them via a dust
passage 24 to a dust container 25 arranged in the centre of the
cleaner body 11. Behind the brush roll 19 an engine 81 for rotating
the brush roll is arranged. The engine is arranged close to the
longitudinal axis L with the drive shaft 82 extending substantially
parallel to the brush roll 19. The drive shaft 82 is extending all
the way to one of the brush roll ends where the drive shaft via a
drive transmission rotates the brush roll 19. The engine is
arranged close to the bottom structure 83 of the cleaner free space
within the cleaner body behind and above the engine. The engine is
preferably an electrical engine powered by two battery packs 84
arranged close to the inner surface of the cleaner casing 12 in the
aft of the clearer body. Two small battery packs are more easily
fitted within the cleaner body than one larger battery and the
position of the battery packs in the aft increases the space in the
centre of the cleaner body for the dust container 25.
[0035] Immediately behind the brush roll 19 and adjacent to each
end of the brush roll a drive unit 85 is arranged. Each drive unit
85 comprises an individually controlled and powered wheel 86 for
supporting the cleaner on the floor surface, an electrical engine
87 for transmission and steering of the cleaner and a wheel
suspension 88 in order to make it possible for the cleaner to move
over rough floor structures. The cleaner is furthermore supported
on the floor surface by a third aft wheel 89.
[0036] In the centre of the cleaner body, behind the brush roll,
the brush roll engine and the drive units the cavity 90 for the
dust container is formed. The cavity is open towards the top
surface 18 of the cleaner casing to facilitate both the fitting and
removal of the dust container 45 from the cleaner body 11.
[0037] The autonomous cleaner furthermore comprises a side brush
unit 91 arranged close to one of the brush roll ends. The side
brush unit comprises a side brush 92 rotating around a
substantially vertical axis to sweep dust and particles towards the
brush roll 19 and improve the cleaning in close corners or close to
for example a wall structure or furniture. The side brush is
rotated by a small electrical engine 93 arrange above the vertical
shaft.
[0038] The dust passage 24 is arranged to direct air and debris
from the brush roll to the dust container and has a width
corresponding to the length of the brush roll and a forward opening
23 arranged adjacent to the brush roll such that the collected
particles could enter the opening 23 easily. The passage 24 is
slightly curved and ended by an aft opening 26 arranged in contact
with a corresponding inlet opening 27 of the dust container 25 to
lead the particles from the brush roll backwards to the dust
container 25. The container 25 is illustrated separately in FIG. 3
and will be described in detail further down this description.
[0039] In the aft end of the cleaner 10, a fan 50 and an electrical
engine 51 for powering the fan are arranged to create a flow of air
through the cleaner 10. The air is sucked into the forward opening
23 of the dust passage 24 and continues via the dust passage 24 to
the dust container 25 to assist the brush roll by sucking dust and
particles from the floor surface and the brush roll and lead the
dust and particles to the dust container 25. The air continues via
a dust compartment 32 through a filter 30 arranged in the dust
container 25 above the inlet opening to ensure that dust and
particles remain in the dust container before the air continues to
an outlet opening 28 in the aft end of the dust container 25 and
exits the cleaner via an outlet passage 31 in the aft end 14 of the
cleaner casing. The air flow through the cleaner 10 is illustrated
in FIG. 2 by a number of small arrows A.
[0040] The dust container 25 comprises a container wall 31 formed
of for example a plastic material. The container wall 31 encloses a
dust compartment 32 for collected dust and particles formed in the
centre of the dust container 25. The dust compartment 32 is defined
by the surrounding dust container wall 31 and the filter extending
within the dust container across the entire path from the inlet to
the outlet to ensure a large filter area and that all air pass the
filter. In the illustrated embodiment of the autonomous cleaner the
dust compartment has a volume within the range of 0.6 to 0.8
litres. The dust container 25 comprises a first side 33 arranged in
the forward end of the container and intended to be arranged
substantially parallel to the aft end of the dust passage 24 and
the brush roll. In the illustrated embodiment the first side 33 is
slightly angled to correspond to the aft end of the dust passage.
However, modifications are possible as long as the aft end of the
dust passage 24 and the first side 33 of the dust container 25 have
corresponding shapes and fit together. In the first side the inlet
opening 27 to the dust chamber 32 is formed. The inlet opening 27
is elongated to provide a large inlet area and facilitate the flow
of air, particles and dust into the dust chamber.
[0041] The dust container 25 furthermore comprises a second side 34
arranged opposite to the first side 33 and arranged substantially
parallel to the first side. The second side 34 is arranged in the
aft end of the dust container 25 and is substantially flat and
intended to be arranged substantially transverse to the
longitudinal axis L of the cleaner 10. The outlet opening 28 is
formed in the second side 34 of the container 25.
[0042] The first and second side of the container are connected by
side surfaces 35 extending between the first and second side to
enclose the dust chamber 32, and a substantially flat bottom
surface 40. The side surfaces 35 have a slightly curved shape but
could be modified in several ways as long as the dust container fit
in the provided space within the cleaner body.
[0043] The illustrated dust container has a shape corresponding to
the shape of the cleaner body, i.e. a wide forward end and a
narrower aft end to provide as large dust container volume as
possible. In order to facilitate the removal of dust and particles
collected in the dust container, the dust container 25 is divided
in an upper 36 and a lower section 37. The upper section 37 serves
as a lid that is used to open and close the dust container. The
upper and lower section is turnably connected to each other by for
example one or more hinges 38 arranged along one of the
corresponding sides of the upper and lower section. The upper
section of the container wall comprises a substantially flat top
surface 41 facing upwards and intended to constitute an outside
upper surface section of the cleaner casing when the dust container
is correctly fitted in the cleaner. Letting the top side 41 of the
dust container constitute a section of the cleaner casing saves
space and simplifies the structure of the cleaner body and the
cleaner casing which makes it possible to increase the dust
container volume further which is very favourable since the time
between required emptying of the dust container is increased.
[0044] The inlet opening 27 is arranged in the lower section 37
while the outlet opening is arranged in the upper section 36. The
dust container 25 furthermore comprises releasable securing means
39 arranged on the upper and/or lower section to maintain the upper
and lower section in the closed position. In the illustrated
embodiment the securing means 39 are embodied as a resilient hook
42 arranged on the upper section and intended to grip a not
illustrated recess in the lower section thereby securing the two
sections together. The securing means are released by pressing the
resilient hook 42 to disengage the recess. The resilient hook is
accessible via an opening in the top side of the cleaner casing.
Within the dust container 25 the filter 30 is arranged. The filter
30 is arranged in the upper section 36 of the dust container and is
intended to move together with the upper section when the dust
container is opened. The filter divides the space within the dust
container in a dust compartment on one side of the filter and an
outlet compartment on the opposite side of the filter. The volume
of the dust compartment in relation to the overall volume within
the dust container should preferably be as large as possible to
extend the time between emptying of the dust container. The filter
is arranged slightly angled in relation to a horizontal plane in
the upper section between the inlet opening 27 and the outlet
opening 28 such that the flow of air must pass through the filter
30. The filter 30 has a shape corresponding to the shape of the
dust container in the intended filter position and extends across
the entire cross section of the dust chamber to maximise the filter
area. The filter could be made of any known filter material, soft
or stiff, as long as the desired filter characteristics are
achieved. However, the filter material is preferably washable and
possible to reuse to reduce waste material.
[0045] The illustrated filter arrangement comprises a frame 43
surrounding a filter area 44 of filter material. The filter
material of the filter area must be replaced or cleaned regularly
and could be removed from the frame 43 without efforts. The frame
43 is designed to fit within the upper section of the dust
container during use of the cleaner. The filter is arranged between
the outlet opening and a surrounding edge 45 of the upper section
that is facing the lower section. The filter frame is movably
secured in the upper section 36 of the dust container by at least
one hinge in order to be movable between a secured position within
the upper section, i.e. the intended filter position during use of
the autonomous cleaner, and an open position where the space inside
the filter adjacent to the outlet opening is accessible to make it
possible to replace the filter material within the frame or the
entire filter alternatively clean the filter and the space within
the upper section normally closed by the filter 30.
[0046] The dust container 25 or the container body furthermore
comprises means for securing the dust container in the autonomous
cleaner, not illustrated in the appended figures. The means for
securing the dust container are fitted in the container wall on the
outside surface of the container wall and/or in the cleaner body.
The dust container is secured in the correct position within the
cleaner body by the securing means but could be released by a
release button 47 accessible from the outside of the cleaner
casing. The release button 47 is positioned on the top side of the
cleaner casing adjacent to the first side of the container in the
forward end of the cleaner. The dust container is released by
pressing the release button.
EXAMPLE
[0047] As described in the summary of the invention, the dust
compartment volume is defined as the volume within the dust
container usable for particles, debris and dust and the volume of
the cleaner body the volume within the cleaner body with the volume
of the dust container included in the cleaner body volume.
[0048] For the autonomous cleaner illustrated in the appended
figures the following numbers have been determined:
Cleaner body volume 5.15 Liters
Dust compartment volume 0.7 Liters
Ratio =Dust compartment volume/Cleaner body volume =0.7/5.15
=0.136
[0049] The dust compartment volume as well as the cleaner body
volume will however change if the design of the autonomous cleaner
is modified but in order to ensure that the desired extended time
period between the required emptying of the dust container and the
limited overall size of the autonomous cleaner the ration between
the dust compartment volume and the cleaner body volume should be
within the range 0.1 to 0.2.
[0050] Furthermore the dust compartment preferably has a volume
exceeding 0.6 liters to ensure the desired extended time period
between the required emptying of the dust container, and preferably
the cleaner body volume does not exceed 7 liters to keep the
overall dimensions of the cleaner body small which is essential to
make it possible for the autonomous cleaner to turn and access
narrow passages or floor areas.
[0051] The embodiments described above could be combined and
modified in different ways without departing from the scope of the
invention that is defined by the appended claims.
* * * * *