U.S. patent application number 10/619150 was filed with the patent office on 2004-03-18 for floor cleaning apparatus.
Invention is credited to Angle, Colin, Chiappetta, Mark, Coltof, Gideon, Connors, Robert A., Jones, Joseph L., Kay, Robert K., Mass, Phillip R., O'Brien, John P., Robert, Rosario, Sandin, Paul E., Sharma, Jayant, Slipichevich, Selma, Sword, Lee F., Thomas, Victor W. SR., Wirz, Benjamin L..
Application Number | 20040049878 10/619150 |
Document ID | / |
Family ID | 22480831 |
Filed Date | 2004-03-18 |
United States Patent
Application |
20040049878 |
Kind Code |
A1 |
Thomas, Victor W. SR. ; et
al. |
March 18, 2004 |
Floor cleaning apparatus
Abstract
A floor cleaner is provided for cleaning a floor, where the
floor cleaner has a front and a rear and includes: a sweeper for
sweeping the floor; a scrubber, connected to the sweeper and
located in the rear of the sweeper, for wetting and cleaning the
floor; and a burnisher, connected to the scrubber and located in
the rear of the scrubber, for burnishing the floor.
Inventors: |
Thomas, Victor W. SR.;
(Racine, WI) ; Kay, Robert K.; (Butternut, WI)
; Sharma, Jayant; (Racine, WI) ; Mass, Phillip
R.; (Boston, MA) ; Robert, Rosario;
(Cambridge, MA) ; Angle, Colin; (Watertown,
MA) ; Sword, Lee F.; (Methuen, MA) ; Jones,
Joseph L.; (Acton, MA) ; Sandin, Paul E.;
(Randolph, MA) ; O'Brien, John P.; (Brighton,
MA) ; Wirz, Benjamin L.; (Groton, MA) ;
Slipichevich, Selma; (Chelmsford, MA) ; Chiappetta,
Mark; (Shelton, CT) ; Coltof, Gideon;
(Allston, MA) ; Connors, Robert A.; (Tewksbury,
MA) |
Correspondence
Address: |
S.C. JOHNSON COMMERCIAL MARKETS INC
8310 16TH STREET, M/S 510
PO BOX 902
STURTEVANT
WI
53177-0902
US
|
Family ID: |
22480831 |
Appl. No.: |
10/619150 |
Filed: |
July 14, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10619150 |
Jul 14, 2003 |
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09588414 |
Jun 6, 2000 |
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60138179 |
Jun 8, 1999 |
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Current U.S.
Class: |
15/320 ;
15/340.4 |
Current CPC
Class: |
A47L 11/4036 20130101;
A47L 11/4088 20130101; A47L 11/4041 20130101; A47L 11/30 20130101;
A47L 11/4069 20130101; A47L 11/4052 20130101; A47L 11/282 20130101;
A47L 11/14 20130101; A47L 11/4038 20130101; A47L 11/4011 20130101;
A47L 11/4044 20130101; A47L 11/24 20130101 |
Class at
Publication: |
015/320 ;
015/340.4 |
International
Class: |
A47L 005/00; E01H
001/08 |
Claims
What is claimed is:
1. A floor cleaning device for cleaning a floor, the floor cleaner
having a front and a rear, the floor cleaner comprising: a scrubber
for wetting and cleaning the floor, and a burnisher located to the
rear of the scrubber for burnishing the floor, wherein said
scrubber comprises a brush having an axis of rotation substantially
parallel to the floor and substantially perpendicular to an axis
running from the front to the rear of the cleaner.
2. The cleaner of claim 1 wherein said scrubber brush includes
polymeric bristles.
3. The cleaner of claim 2 wherein said bristles range from 0.1 mm
to 0.5 mm in diameter.
4. The cleaner of claim 1 wherein a flexible blade for collecting
bulk water is positioned to contact the floor between the scrubber
and the burnisher.
5. The cleaner of claim 4 further including a vacuum source for
applying suction to a portion of the floor in front of said
flexible blade to collect liquid gathered by said blade.
6. The cleaner of claim 5 further comprising a second flexible
blade positioned in front of, and spaced apart from said first
flexible blade, the vacuum source applying said suction to the
space between the first and second blades.
7. The cleaner of claim 1 wherein the burnisher includes a
burnisher pad and the scrubber includes a scrubber brush, the
burnisher and the scrubber being positioned relative to one another
such that a front-most point of the burnisher pad is located less
than 40 cm from a rear-most point of contact of the scrubber brush
with the floor.
8. The cleaner of claim 1 wherein the burnisher includes a
burnisher pad and a motor for spinning the burnisher pad at a speed
at or above 1000 rpm.
9. The cleaner of claim 8 wherein the motor is an electric
motor.
10. The cleaner of claim 1 which further includes a sweeper mounted
forward of the scrubber.
11. A floor cleaner for cleaning a floor, the floor cleaner having
a front and a rear, the floor cleaner comprising a sweeper, a
scrubber mounted to the rear of the sweeper for wetting and
cleaning the floor, and a burnisher located to the rear of the
scrubber for burnishing the floor.
12. The cleaner of claim 11 wherein the sweeper comprises: one or
more rotating sweeper elements, a hopper spaced from said sweeper
elements, and a ramp, connected to said hopper and located between
the sweeper elements and the hopper, a portion of the ramp being
located under a portion of the sweeping elements.
13. A floor cleaner for cleaning a floor, the floor cleaner having
a front and a rear, the floor cleaner comprising: a scrubber for
wetting and cleaning the floor, and a burnisher located to the rear
of the scrubber for burnishing the floor, wherein the distance
between the scrubber and the burnisher is no greater than 40
cm.
14. A floor cleaner for cleaning a floor, the floor cleaner having
a front and a rear, the floor cleaner comprising: a scrubber for
wetting and cleaning the floor, and a burnisher located to the rear
of the scrubber for burnishing the floor, and liquid removal
apparatus for removing bulk liquid from the floor, said apparatus
located between the scrubber and the burnisher, wherein the point
of liquid removal from the floor is located within 25 cm of the
burnisher.
15. The cleaner of claim 14 wherein the point of liquid removal
from the floor is located within 10 cm of the burnisher.
16. A method of cleaning and burnishing a polymeric coating on a
floor surface comprising scrubbing the floor using a composition
comprising water, wherein the scrubbing comprises using a bristled
brush and causing the bristles to contact the floor in a
substantially straight path and thereafter burnishing the
floor.
17. A method of cleaning and burnishing a polymeric coating on a
floor surface comprising scrubbing the floor using a composition
comprising water, permitting the coating to absorb an additional
amount of water and burnishing the floor while the coating contains
said additional amount of water.
18. The method of claim 17 wherein said polymeric coating is
hydrophilic.
19. A method of burnishing a polymeric coating on a floor surface
which comprises burnishing said coating while the coating is in a
softened state.
20. A method of burnishing a polymeric coating on a floor surface
which comprises burnishing said coating while the cating contains
substantial absorbed water.
21. A cleaner for cleaning a floor comprising a first assembly of
components for performing a first cleaning operation on the floor,
a second assembly of components for performing a second cleaning
operation on the floor, control circuitry, connected to the first
and second assemblies, executing in parallel a first program module
operating the first assembly and a second program module operating
the second assembly.
22. The cleaner of claim 21 wherein the first program supplies data
to the second program, and the second program modifies the
operation of the second assembly based on said data.
23. The cleaner of claim 21 wherein the control circuitry comprises
at least two processors, one processor executing the first program
and the second processor executing the second program.
24. The cleaner of claim 21 wherein the first assembly includes a
scrubber and the second assembly includes a burnisher.
25. The cleaner of claim 24 further comprising: a third assembly of
components for sweeping the floor, wherein the control circuitry is
further connected to the third assembly and executes, in parallel
with the first and second program modules, a third program module
operating the third assembly.
26. A cleaner for cleaning a floor comprising a first assembly of
components for performing a first cleaning operation on the floor,
a second assembly of components for performing a second cleaning
operation on the floor, control circuitry, connected to the first
and second assemblies, executing in parallel a first and second
program modules, the first program module comprising a first
plurality of instructions for controlling the operations of the
first and second assemblies and coordinating among the operations
of the first and second assemblies, the second computer program
module comprising a second plurality of instructions for
controlling the operations of the first and second assemblies,
wherein the first plurality of instructions includes an instruction
for supplying a command from the first program module to the second
program module, the command requiring performance of a sequence of
actions by at least one of the first and second assemblies, wherein
the first program module, after executing the instruction for
supplying the command, executes other instructions independent of
performance of said sequence of actions, the second plurality of
instructions including a sequence of instructions for causing said
at least one of the first and second assemblies to perform said
sequence of actions, the second program module executing the
sequence of instructions independent of the first program
module.
27. The cleaner of claim 26 wherein the control circuitry comprises
at least two processors, one processor executing the first program
module and the second processor executing the second program
module.
28. The cleaner of claim 26 wherein the first assembly includes a
scrubber and the second assembly includes a burnisher.
29. The cleaner of claim 28 further comprising: a third assembly of
components for sweeping the floor, wherein the control circuitry is
further connected to the third assembly, wherein the first program
module further comprises a third plurality of instructions for
operating the third assembly and coordinating among the operations
of the third assembly, and the first and second assemblies, wherein
the second computer program module further comprises a fourth
plurality of instructions for operating the third assembly, wherein
the second plurality of instructions includes an instruction for
supplying a second command from the first program module to the
second program module, the command requiring performance of a
second sequence of actions by the third assembly, wherein the first
program module, after executing the instruction for supplying the
second command, executes other instructions independent of
performance of said second sequence of actions, the second
plurality of instructions including a second sequence of
instructions for causing the third assembly to perform said second
sequence of actions, the second program module executing the second
sequence of instructions independent of the first computer program
module.
30. A cleaner comprising a first assembly of components for
performing a first cleaning operation, a second assembly of
components for performing a second cleaning operation, control
circuitry, connected to the first and second assemblies,
coordinating an operation of the first assembly relative to an
operation of the second assembly based on a distance traveled by
said cleaner.
31. A floor cleaner comprising: a sweeper assembly including at
least one retractable, rotatable sweeper brush for sweeping the
floor; a scrubber assembly including at least one retractable,
rotatable scrubber head, a source of cleaning fluid, and a vacuum
source for cleaning the floor; a burnisher assembly including at
least one retractable, rotatable burnishing pad for burnishing the
floor and, a control system receiving as an input at least a
cleaning mode command, the control system including circuitry
configured, in response to the cleaning mode command, to
automatically provide signals which: cause the sweeper brush to
rotate and lower, cause the scrubber head to rotate and lower,
cause the source of cleaning fluid and the vacuum source to
operate, and, cause the burnishing pad to rotate and lower in
accordance with a predefined sequence.
32. The cleaner of claim 31 further including at least one
rotatable drive wheel and wherein the control system further
includes circuitry configured to cause the drive wheel to rotate
automatically in response to receiving a drive command to engage
the drive wheel.
33. The floor cleaner of claim 32 of which the control system
further includes circuitry configured, in response to the absence
of either the cleaning mode command or the drive command, to
provide signals which first cause the source of cleaning fluid to
turn off and then, after a time delay, cause the vacuum source to
turn off, and cause the scrubber head to stop and raise.
34. The floor cleaner of claim 31 in which the control system
circuitry, in a predefined sequence, provides signals which cause
the sweeper brush, the scrubber head and the burnishing pad to
raise and stop, and cause source of cleaning fluid and the vacuum
source to stop operation automatically in response of the absence
of the cleaning mode command.
35. A floor cleaner comprising: a retractable sweeper assembly
including: at least one rotatable sweeper brush, a sweeper brush
motor for rotating the sweeper brush, and a sweeper assembly motor
for raising and lowering the sweeper brush; a retractable scrubber
assembly including: at least one rotatable scrubber head, a
squeegee assembly proximate the scrubber head, a scrubber head
motor for rotating the scrubber head, a scrubber assembly motor for
raising and lowering the scrubber head and the squeegee assembly, a
cleaning fluid pump for supplying cleaning fluid proximate the
scrubber head, and a vacuum source including an inlet proximate the
scrubber head; a retractable burnisher assembly including: at least
one rotatable burnishing pad, a burnishing pad motor for rotating
the burnishing pad, and a burnisher assembly motor for raising and
lowering the burnishing pad; and a control system including
circuitry configured, upon command, to automatically, selectively
energize and deenergize the sweeper brush motor, the sweeper
assembly motor, the scrubber head motor, the scrubber assembly
motor, the cleaning fluid pump, the vacuum source, the burnishing
pad motor, and the burnisher assembly motor in accordance with
preselected sequence.
36. A floor cleaner comprising: at least two retractable head
assemblies each including at least one rotatable head; and a
control system including circuitry configured to automatically
provide signals for lowering both head assemblies and rotating both
heads upon the receipt of a command and in accordance with a
predefined sequence.
37. The floor cleaner of claim 36 in which one said retractable
head assembly includes a scrubber brush, a squeegee assembly
proximate the scrubber brush, a source of cleaning fluid, and a
vacuum source.
38. The floor cleaner of claim 37 in which the control system
circuitry provides signals which cause the scrubber brush and the
squeegee assembly to lower, and which begin the operation of the
scrubber brush, the source of cleaning fluid, and the vacuum source
automatically upon the issuance of only a single command.
39. The floor cleaner of claim 37 in which the control system
circuitry provides signals which cause the scrubber brush and the
squeegee assembly to raise and which stop the operation of the
scrubber head, the source of cleaning fluid, and the vacuum source
automatically upon the issuance of only a single command.
40. The floor cleaner of claim 39 in which the predefined sequence
includes providing signals which stop the operation of the source
of cleaning fluid before the squeegee assembly is raised and the
vacuum source is turned off.
41. A floor cleaner for cleaning a floor comprising: a scrubber for
wetting and cleaning the floor, and a member being mounted for
movement from a first position to a second position, wherein in the
first position the member prevents cleaning liquid from the
scrubber brush to fall on the floor and in the second position the
member prevents the cleaning liquid from the scrubber brush to
splash against at least a portion of the cleaner.
42. A floor cleaner for cleaning a floor comprising: a scrubber for
wetting and cleaning the floor, a squeegee blade, and a squeegee
mount for housing the squeegee blade, wherein the squeegee mount
includes a groove for slidably mounting the squeegee blade.
Description
RELATED APPLICATIONS
[0001] This application claims priority of U.S. Provisional
Application Serial No. 60/138,179 filed Jun. 8, 1999.
FIELD OF THE INVENTION
[0002] This invention relates to floor cleaning systems or cleaners
for cleaning floors such as waxed floor surfaces including Vinyl
Composition Tile (VCT) floors with a glossy polymeric finish such
as an Ultra High Speed (UHS) commercial finish.
BACKGROUND OF THE INVENTION
[0003] Modem resilient and hard flooring materials are often coated
with polymer coatings which may be natural or synthetic polymers,
sometimes referred to as "floor waxes". These coating materials can
impart various types of finish to the floors. Acrylic polymers are
often used on such floors where a transparent, glossy finish is
desired. Following application of the coating materials, the floor
must be periodically swept, scrubbed and polished to restore the
shine worn by foot and other traffic on the floor. For glossy
floors, the burnishing and other operations may be performed
daily.
[0004] Cleaning of polymer coated resilient and hard floor
materials has traditionally comprised the operations of sweeping,
scrubbing and burnishing. These operations are generally performed
separately in the recited order. The coated floor is initially
swept or dust mopped to remove dust and larger debris particles so
that they will not be acted upon by the scrubbing and/or burnishing
steps that follow and cause discoloration or damage to the floor
coating. After sweeping, the floor is cleaned by scrubbing with
water and other additives such as soaps, surfactants and the like
and left to dry under ambient conditions, with or without bulk
liquid being first removed by a squeegee operation separate from,
or in conjunction with, the scrubbing operation. After scrubbing,
the dry floor coating may be burnished with a burnishing device to
provide a luster or shine to the coating surface which is an
appearance often desired in commercial buildings. The burnisher is
typically a propane powered device which rotates a flat, circular
polishing pad at relatively high speed to polish the floor
coating.
[0005] The above operations have generally been performed manually
in three separate steps. More recently, mechanical, powered
sweepers, scrubbers and burnishers have become available. Often a
single operator will perform the operations serially.
SUMMARY OF THE INVENTION
[0006] The present inventors have discovered that performing the
burnishing operation with one or more of the sweeping and/or
scrubbing operations is advantageous. Combining the scrubbing and
burnishing operations, in a unitary, coordinated method or system
so that the operations are performed serially, but closely spaced
in time, is particularly desirable and provides certain advantages
not previously achieved or recognized.
[0007] In addition, a preferred embodiment of the present invention
includes at least scrubbing and burnishing, and most preferably all
three operations, in a single unitary device with logical
electronic and mechanical controls that allow a single operator to
easily manipulate all of activities of the floor cleaning
operations simultaneously. This permits all three traditional
operations to be performed with a single pass of the floor cleaning
device over a given floor area. Advantages include the saving of
labor and time as well as ensuring that the burnishing operation
will never be performed on an unclean floor which could result in
forcing the soil into the surface causing discoloration or severe
damage to the coating surface. More surprisingly, the present
system provides enhanced performance compared to the conventional
operations performed serially at widely spaced intervals using
separate devices. More particularly, the burnishing operation
provides enhanced results, such as increased gloss, when performed
closely following the scrubbing operation.
[0008] In a presently preferred embodiment of the invention, the
system comprises a mechanical structure wherein each of the
selected cleaning operations is included in a single device having
a unitary structure for operation by a single operator.
Alternatively, the system may be a "train" of devices coordinated
mechanically or electronically by a single operator. An important
feature is that the scrubbing and burnishing operations be
performed in the desired order and in close proximity in time while
the coating is in a deformable, plastic state.
[0009] As used in this application, the term "coating" or "wax"
refers to widely used polymeric coating materials which are applied
to a relatively smooth natural or synthetic resilient or hard
flooring material, such as vinyl tile or natural stone or other
synthetic, hard or resilient materials. Typically these coatings
comprise one or more natural and/or synthetic polymers, such as the
hard Carnauba waxes, or a mixture of materials containing a
synthetic polymer such as an acrylic polymer. The coating should be
solid at room temperature and transparent and hard enough to
provide protection for the underlying flooring and stand up to
pedestrian traffic. Because these coatings can be damaged or marked
during use, such surfaces are typically maintained by periodic
sweeping, wet scrubbing and/or burnishing. The acrylic polymer
coatings are preferred for floors that are maintained in a high
gloss state.
[0010] As used in this application, the term "sweeping" refers to a
dry operation involving removing dust and larger particles from a
floor surface such as by dust mopping, brushing, vacuuming or
blowing or the like so that loose soil particles and other
materials are not present during the scrubbing or burnishing
operations where their presence could inhibit the cleaning or
burnishing or cause a discoloration of the coating or other
physical damage to the floor surface during the more aggressive
scrubbing and burnishing operations.
[0011] The term "scrubbing" as used with respect to this invention
refers to a wet operation involving the application of water and/or
other common cleaning compositions to a coated floor surface
together with scrubbing the floor surface with mops, rotating pads
or brushes or other cleaning tools. In the present invention it has
been discovered that a cylindrical brush having relatively soft,
synthetic polymeric bristles is preferred which may be rotated at
speeds of from about 500 to 2000 rpm. The scrubbing operation may
also involve removal of bulk surface liquid from the floor
following scrubbing, such as by evaporation, vacuuming or a
mechanical squeegee operation or a combination thereof.
[0012] The term "burnishing" as used herein means the relatively
high-speed polishing of the coating surface of the floor after
scrubbing to provide a glossy, reflective surface. Modem burnishing
tools generally comprise an electric or gas or liquid fuel powered
machine for rotating a flat, circular fibrous pad at relatively
high speed (for example 1000 to 4000 rpm) to polish the
surface.
[0013] The "gloss" of the coating is measured by a gloss meter
which directs a beam of light normal to the surface of the floor
and measures the reflection of the light at angles of 20 degrees
and/or 60 degrees from normal. The percentage of the light
reflected is reported as the "gloss" of the floor coating. A
difference of 5 points on the gloss meter represents a difference
which can be perceived as significant by the human eye.
[0014] In one general aspect, the invention features a floor
cleaner for cleaning a floor, where the floor cleaner has a front
and a rear and includes: an optional sweeper for sweeping the
floor; a scrubber, connected to the sweeper and located in the rear
of the sweeper, for wetting and cleaning the floor; and a
burnisher, connected to the scrubber and located in the rear of the
scrubber, for burnishing the floor.
[0015] Embodiments of this aspect of the invention may include one
or more of the following features.
[0016] The cleaner is sized to operate within aisles having
dimensions greater than or equal to about 24 inches.
[0017] The sweeper includes two counter-rotating brushes, one or
both of which is driven by a motor. The brushes are positioned
relative to one another such that bristles of the brushes overlap.
The sweeper includes a hopper spaced from the brushes, and a ramp
which is connected to the hopper and located between the brushes
and the hopper. A portion of the ramp is located under a portion of
the brushes. A portion of the ramp is curved upwardly along an axis
extending from the brushes to the hopper. The brushes are mounted
on the frame for retraction substantially along a vertical
axis.
[0018] The scrubber includes a scrubber brush which has an axis of
rotation substantially parallel to the floor and substantially
perpendicular to an axis running from the front to the rear of the
cleaner. The scrubber brush includes 0.15 mm diameter polymeric
bristles. The scrubber is pivotally mounted on the frame for
retraction.
[0019] A cleaning liquid dispenser dispenses cleaning liquid. The
cleaning liquid dispenser includes a liquid dispensing trough
positioned substantially parallel to the axis of rotation of the
scrubber brush and is substantially coextensive with the scrubber
brush. The liquid dispensing trough has at least one opening for
dispensing a cleaning liquid.
[0020] The scrubber includes a member which is mounted for movement
from a first position to a second position. In its first position,
the member prevents cleaning liquid from the scrubber brush to fall
on the floor. In its second position, the member prevents the
cleaning liquid from the scrubber brush to splash against at least
a portion of the cleaner. The member extends along the length of
the scrubber brush and is rotatable between the first and second
positions around a second axis substantially parallel to the axis
of rotation of the scrubber brush.
[0021] A squeegee blade is positioned in the rear of the scrubber
brush along a second axis parallel to the axis of rotation of the
scrubber brush. A vacuum source applies suction to a portion of the
floor in front of the squeegee blade to collect liquid gathered by
the squeegee blade. A second squeegee blade is positioned in front
of, and spaced apart from, the first-mentioned squeegee blade. The
vacuum source applies the suction to the space between the
first-mentioned and the second squeegee blades.
[0022] A cleaning liquid system includes the vacuum source, the
cleaning liquid dispenser, a chamber for separating the cleaning
liquid from a mixture of air and cleaning liquid collected by the
suction applied to the floor by the vacuum source, and a filter for
filtering out dirt from the separated cleaning liquid prior to
dispensing the separated cleaning liquid by the cleaning liquid
dispenser. The chamber is shaped and sized to reduce a velocity of
a flow of the mixture of air and cleaning liquid to separate the
cleaning liquid from the mixture of air and cleaning liquid. A
squeegee mount houses one or both of the squeegee blades, where the
squeegee mount includes grooves for slidably mounting the squeegee
blades. The grooves are typically key-hole shaped, and portions of
the squeegee blades may be key-shaped and sized to fit in the
grooves. The squeegee mount defines a cavity between the first and
second grooves, at one end the cavity opening to the space between
the squeegee blades and at another end connecting to a vacuum
source. The squeegee mount is pivotally mounted on the frame for
vertical retraction.
[0023] The burnisher and scrubber are positioned relative to one
another such that a frontmost point of a burnisher pad of the
burnisher is located between 10 cm and 40 cm from a rear-most point
of contact of the scrubber brush to the floor. The burnisher pad
includes a burnishing pad and a motor for spinning the burnisher
pad. The burnisher is mounted on the frame for vertical retraction
substantially along a vertical axis. The burnisher is mounted on
the frame by a four bar linkage which floatingly supports the
burnisher pad near the floor during operation.
[0024] The cleaner has a drive wheel, and a motor which is
disengagably coupled to the drive wheel and drives the drive wheel.
A control circuitry controls a velocity of the drive wheel by
measuring the velocity, comparing the measured velocity to a
selected velocity, and adjusting the velocity of the drive wheel
based on a result of the comparison.
[0025] In another general aspect, the invention features a floor
cleaner for cleaning a floor which includes: a scrubber for wetting
and cleaning the floor; and a member being mounted for movement
from a first position to a second position, where in the first
position the member prevents cleaning liquid from the scrubber
brush to fall on the floor and in the second position the member
prevents the cleaning liquid from the scrubber brush to splash
against at least a portion of the cleaner.
[0026] In yet another general aspect, the invention features a
cleaner which includes a scrubber for wetting and cleaning the
floor, a squeegee blade, and a squeegee mount for housing the
squeegee blade, where the squeegee mount includes a groove for
slidably mounting the squeegee blade.
[0027] In yet another general aspect, the invention features a
cleaner for cleaning a floor, where the cleaner includes: a first
assembly of components for performing a first cleaning operation on
the floor; a second assembly of components for performing a second
cleaning operation on the floor; and control circuitry, connected
to the first and second assemblies, executing in parallel a first
program module operating the first assembly and a second program
module operating the second assembly.
[0028] Embodiments of this aspect of the invention may include one
or more of the features below.
[0029] The first program supplies data to the second program, and
the second program modifies the operation of the second assembly
based on the data.
[0030] The control circuitry comprises at least two processors, one
processor executing the first program and the second processor
executing the second program.
[0031] The first assembly includes a scrubber and the second
assembly includes a sweeper.
[0032] The cleaner includes a third assembly of components for
burnishing the floor, where the control circuitry is further
connected to the third assembly and executes, in parallel with the
first and second program modules, a third program module operating
the third assembly.
[0033] In one other general aspect, the invention features a
cleaner for cleaning a floor, where the cleaner includes: a first
assembly of components for performing a first cleaning operation on
the floor; a second assembly of components for performing a second
cleaning operation on the floor; control circuitry, connected to
the first and second assemblies, executing in parallel a first and
second program modules; where the first program module includes a
first plurality of instructions for controlling the operations of
the first and second assemblies and coordinating among the
operations of the first and second assemblies and the second
computer program module includes a second plurality of instructions
for controlling the operations of the first and second assemblies;
where the first plurality of instructions includes an instruction
for supplying a command from the first program module to the second
program module, the command requiring performance of a sequence of
actions by at least one of the first and second assemblies, where
the first program module, after executing the instruction for
supplying the command, executes other instructions independent of
performance of the sequence of actions; and where the second
plurality of instructions includes a sequence of instructions for
causing the at least one of the first and second assemblies to
perform the sequence of actions, the second program module
executing the sequence of instructions independent of the first
program module.
[0034] Embodiments of this aspect of the invention may include one
or more of the following features.
[0035] The control circuitry has at least two processors, one
processor executing the first program module and the second
processor executing the second program module. The first assembly
includes a scrubber and the second assembly includes a sweeper.
[0036] The cleaner has a third assembly of components for
burnishing the floor, where the control circuitry is further
connected to the third assembly. The first program module further
includes a third plurality of instructions for operating the third
assembly and coordinating among the operations of the third
assembly, and the first and second assemblies. The second computer
program module includes a fourth plurality of instructions for
operating the third assembly. The second plurality of instructions
includes an instruction for supplying a second command from the
first program module to the second program module, the command
requiring performance of a second sequence of actions by the third
assembly, where the first program module, after executing the
instruction for supplying the second command, executes other
instructions independent of performance of the second sequence of
actions. The second plurality of instructions includes a second
sequence of instructions for causing the third assembly to perform
the second sequence of actions, the second program module executing
the second sequence of instructions independent of the first
computer program module.
[0037] In another general aspect, the invention features a cleaner
which includes: a first assembly of components for performing a
first cleaning operation; a second assembly of components for
performing a second cleaning operation; and control circuitry,
connected to the first and second assemblies, coordinating an
operation of the first assembly relative to an operation of the
second assembly based on a distance traveled by the cleaner.
[0038] Aspects of the invention may be implemented in hardware or
software, or a combination of both. Preferably, these aspects are
implemented in computer programs executing on programmable
computers that each include a processor, a storage medium readable
by the processor (including volatile and non-volatile memory and/or
storage elements). Program code is applied to data entered through
the input device to perform the functions described above and to
generate output information. The output information is applied to
one or more output devices.
[0039] Each program is preferably implemented in a high level
procedural or object oriented programming language to communicate
with a computer system. However, the programs can be implemented in
assembly or machine language, if desired. In any case, the language
may be a compiled or interpreted language.
[0040] Each such computer program is preferably stored on a storage
medium or device (e.g., ROM or magnetic diskette) that is readable
by a general or special purpose programmable computer for
configuring and operating the computer when the storage medium or
device is read by the computer to perform the procedures described
in this document. The system may also be considered to be
implemented as a computer-readable storage medium, configured with
a computer program, where the storage medium so configured causes a
computer to operate in a specific and predefined manner.
[0041] Other features and advantages of the invention will become
apparent from the following description of preferred embodiments,
including the drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] FIG. 1 is a top, rear perspective view of a cleaner;
[0043] FIG. 2 is a top, front perspective view of the cleaner with
its housing removed;
[0044] FIG. 3 is a cross-sectional view of the cleaner with its
sweeper, scrubber, and burnisher assemblies in lowered
positions;
[0045] FIG. 3A is a cross-sectional view of the cleaner with its
sweeper, scrubber and burnisher assemblies in retracted
positions;
[0046] FIG. 4 is a perspective view of the sweeper assembly of the
cleaner;
[0047] FIG. 4A is a cross-section view of a portion of the sweeper
assembly;
[0048] FIG. 5 is another perspective view of the sweeper assembly
with its hopper removed;
[0049] FIG. 6 is a cross-sectional view of the sweeper
assembly;
[0050] FIG. 7 is a top perspective view of the scrubber assembly of
the cleaner, with an end plate removed for clarity;
[0051] FIG. 8 is a bottom perspective view of the scrubber assembly
with its splash and drip guard in a lowered position;
[0052] FIG. 9 is a cross-sectional view of the scrubber assembly
with its splash and drip guard in a retracted position;
[0053] FIG. 9A is a cross-sectional view of the scrubber assembly
with its splash and drip guard in its lowered position;
[0054] FIG. 10 is a top perspective view of the scrubber
assembly;
[0055] FIG. 11 is a perspective view of a liquid dispenser of the
scrubber assembly;
[0056] FIG. 12 is a perspective view of a squeegee assembly of the
scrubber assembly;
[0057] FIG. 12A is a perspective view of the squeegee assembly with
one of its squeegee blades partially removed;
[0058] FIG. 13 is a cross-sectional view of the squeegee
assembly;
[0059] FIG. 14 is a perspective view of a fluid and vacuum system
of the cleaner;
[0060] FIG. 14A is a top view of the fluid and vacuum system;
[0061] FIG. 15 is a cross-sectional view of the fluid and vacuum
system;
[0062] FIG. 16 is another cross-sectional view of the fluid and
vacuum system;
[0063] FIG. 17 is a perspective view of a burnisher assembly of the
cleaner;
[0064] FIG. 18 is a top view of the burnisher assembly;
[0065] FIG. 19 is a cross-sectional view of the burnisher
assembly;
[0066] FIG. 20 is a schematic diagram of a control system of the
cleaner;
[0067] FIG. 21 is a behavioral diagram of an application program
executed by the control system;
[0068] FIG. 22 is the pseudocode for the steps taken by an error
behavior module of the application program;
[0069] FIG. 23 is the pseudocode for the steps taken by a control
behavior module of the application program;
[0070] FIG. 24 is the pseudocode for the steps taken by a handle
behavior module of the application program;
[0071] FIG. 25 is the pseudocode for the steps taken by an enable
behavior module of the application program;
[0072] FIG. 26 is the pseudocode for the steps taken by a sweep
behavior module of the application program;
[0073] FIG. 27 is the pseudocode for the steps taken by a scrub
behavior module of the application program;
[0074] FIG. 28 is the pseudocode for the steps taken by a drive
behavior module of the application program;
[0075] FIG. 29 is the pseudocode for the steps taken by a distance
behavior module of the application program; and
[0076] FIG. 30 is the pseudocode for the steps taken by a burnish
behavior module of the application program.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0077] Referring to FIGS. 1, 2, 3, and 3A, a cleaner 10 typically
includes a sweeper assembly 12, a scrubber assembly 14, and a
burnisher assembly 16, each of which is mounted on a common frame
18. In one embodiment, cleaner 10 may only include scrubber
assembly 14 and burnisher assembly 16. Cleaner 10 also includes a
housing 20 which is fastened to frame 18. Cleaner 10 is preferably
sized to fit in aisles of typical retail stores such as grocery
stores and department stores. Such aisles typically have widths
greater than or equal to about 24 inches, and more typically
ranging from about 39to about 72 inches.
[0078] Cleaner 10 further includes a vacuum and cleaning liquid
subsystem 30 to which scrubber assembly 14 is connected. Vacuum and
liquid subsystem 30 is responsible for depositing a cleaning liquid
on a scrubber brush of scrubber assembly 10 and recovering the
deposited liquid from the floor. Cleaner 10 also includes batteries
32 which supply power to the various circuits and motors in cleaner
10, including two motors 64 driving a right drive wheel 28 and a
left drive 28B for moving cleaner 10 in various directions.
[0079] Housing 20 has a control panel 22 which can be used by a
user to operate cleaner 10. The controls on control pad 22 provide
the user with the option of choosing to sweep, scrub, burnish, or
perform any combination of these three cleaning operations
including performing all three cleaning operations at once. The
controls on control pad 22 also include an emergency stop button
which the user can use to stop all cleaning operations and
movements of cleaner 10 in the case of an emergency. The controls
further include a speed and direction selector which allows the
user to select among two forward speeds and one reverse speed. The
controls further include a key switch for turning cleaner 10 on and
off. A series of LEDs on control panel 22 indicate to the user
which cleaning functions are being currently performed.
[0080] Cleaner 10 also includes a handle 24 having right and left
pressure sensing pads 26A-B. The user can use these pads to control
the direction of travel of cleaner 10 by directly controlling the
speed of rotation of drive wheels 28A-B. The user can make cleaner
10 turn right by selectively applying pressure to right pressure
sensing pad 26A rather than to left pressure sensing pad 26B.
Similarly, the user can make cleaner 10 turn left by applying
pressure to left pressure sensing pad 26B rather than to right
pressure sensing pad 26A. By pressing both pressure sensing pads
26A-B, the user can make cleaner 10 travel forward in a straight
line. The user can stop cleaner 10 by removing both hands from
pressure sensing pads 26A-B for a predetermined period of time.
[0081] Pressure sensing pads 26A-B and the controls on the control
panel 22 supply control signals to a control subsystem 34
(schematically shown in FIG. 20) which, in accordance with those
signals, operate cleaner 10. Control subsystem 34, among other
things, includes software for automatically controlling the various
cleaning operations of cleaner 10. The application programs are
designed to improve the quality of cleaning operations and reduce
the risk of damage to the floor by ensuring that cleaning
operations are performed in particular sequences. For example, when
the user selects performing all three cleaning operations at the
same time, the application programs ensure that the burnisher
assembly 16 does not burnish a floor surface which has not already
been scrubbed by scrubber assembly 14. Additionally, when the user
selects to stop all cleaning operations, the application programs
ensure that as much as possible the deposited cleaning liquid is
collected from the floor surface prior to stopping all cleaning
operations.
[0082] Having briefly described the structure and operation of
cleaner 10, we will now describe in detail the structure and
operation of each of the subsystems of cleaner 10. These subsystems
are, in the order they will be described: drive wheels 28A-B,
sweeper assembly 12, scrubber assembly 14, burnisher assembly 16,
vacuum and cleaning liquid subsystem 30, and control subsystem
34.
Drive Wheels
[0083] Referring specifically to FIG. 2, each one of drive wheels
28A-B is driven by a dedicated DC servo motor 64 through gear and
chain mechanism 66 (only the mechanism for drive wheel 28A is
shown). Each one of servo motors 64 is controlled by control system
34. Each one of drive wheels 28A-B can be disengaged from its motor
64 by turning a knob 68 on that drive wheel. Drive wheels 28A-B may
also be located between burnisher assembly 16 and scrubber assembly
14, especially when sweeper assembly 12 is absent to provide a
pivot point for cleaner 10 making it easier for the operator to
handle and to negotiate sharp turns.
Sweeper Assembly
[0084] Referring to FIGS. 4, 4A, 5, and 6, sweeper assembly 12
includes two counter-rotating brushes 36A-B, each of which is
respectively driven by one of DC servo motors 38A-B. Motors 38A-B
are connected to a DC servo motor driver in control subsystem 34,
which will be described in further detail below. Brushes 36A-B and
motors 38A-B are mounted on a sweeper frame 40. Brushes 36A-B are
located relative to one another such that their bristles overlap by
approximately 0.5 inch. Sweeper assembly 12 also includes a hopper
42 and a ramp 44 connected to hopper 42. Ramp 44 has a solid metal
portion 46 and a pliable, plastic portion 48. Solid portion 46 has
a curved profile as shown in FIG. 6. Since plastic portion 48 is
pliable, when plastic portion 48 comes into contact with the floor
surface, it will less likely scratch or otherwise damage the floor
surface.
[0085] Hopper 42 has four pegs 50 on an upper portion of its side
walls 42A-B. To mount hopper 42 onto sweeper frame 40, hopper 42 is
slid in between motors 38A-B and into an opening defined by sweeper
frame 40 until each one of pegs 50 is aligned with a corresponding
one of detentes 52. Hopper 42 is then lowered until each one of
pegs 50 rests in the corresponding one of detentes 52 (best shown
in FIG. 5). To remove hopper 42, hopper 42 is lifted up until pegs
50 are clear of detentes 52. Hopper 42 is then slid out of sweeper
frame 40. Hence, hopper 42 can be easily removed to be emptied, and
then can be easily placed back in sweeper frame 40.
[0086] Sweeper assembly 12 includes a mounting frame 54 for
mounting the sweeper assembly onto frame 18 of cleaner 10 (shown in
FIGS. 1-2). Mounting frame 54 is connected to sweeper frame 40 by a
four bar linkage 56. Four bar linkage 56 has four horizontal
members 56A-D, each one of which is pivotally connected at one end
to mounting frame 54 and at another end to sweeper frame 40. Four
bar linkage 54 allows sweeper frame 40 and components attached to
sweeper frame 40 to be retracted and lowered substantially along a
vertical axis.
[0087] The mechanism for retracting and lowering sweeper frame 40
includes a DC servo motor 58 coupled to an off-center cam 60 which
is rotatably coupled to a peg 62 of sweeper frame 40 (best shown in
FIG. 4A). Motor 58 is connected to a DC servo motor driver
controlled by control subsystem 34, as will be described in further
detail below. As motor 58 rotates cam 60, cam 60 either lifts or
lowers peg 62 and thereby retracts or lowers sweeper frame 40.
FIGS. 3-3A show sweeper assembly 12 in its lowered and retracted
positions.
[0088] Referring particularly to FIG. 6, during operation, motors
38A-B cause brushes 36A-B to rotate at about 30 to 100 RPM. Sweeper
assembly 40, together with brushes 36A-B and ramp 44, are then
lowered until brushes 36A-B come into contact with the floor.
Brushes 36A-B sweep the debris in front of the brushes towards
where brushes 36A-B overlap one another over the middle of ramp 44.
There, brushes 36A-B catch the debris between their bristles and
push the debris up ramp 44. The debris travels over curved portion
46 where the debris gains an upward momentum causing the debris to
be effectively thrown into hopper 42.
Scrubber Assembly
[0089] Referring to FIGS. 7-9, 9A, and 10, scrubber assembly 14
includes a scrubber brush 80 rotatably mounted in a scrubber frame
90. Scrubber brush 80 has a horizontal axis of rotation
substantially parallel to the floor surface and substantially
perpendicular to the direction of travel of cleaner 10 during
operation. Because scrubber brush 80 has a horizontal axis of
rotation, it occupies a relatively small space, thereby allowing
cleaner 10 to have components for performing three cleaning
operations, that is, sweeping, scrubbing, and burnishing. For
example, scrubber brush 80 has bristles which are polymeric
bristles, preferably, having a diameter of about 0.15 mm.
[0090] Scrubber frame 90 is constructed out of a number of
segments, and is pivotally connected to a mounting frame 92 by
bolts 94. Mounting frame 92 is in turn mounted onto frame 18 of
cleaner 10 (shown in FIGS. 1-2). A DC servo motor 106 is provided
for rotating housing 90 about bolts 92. Motor 106 is connected to a
gear 106A which engages a wedge-shaped gear 108 bolted to scrubber
frame 90. As motor 106 rotates gear 106A and gear 108, gear 108
acts as a lever and rotates housing 90 about bolts 94. Motor 106 is
connected to a DC servo motor driver controlled by control
subsystem 34, as will be described in further detail below.
[0091] Scrubber brush 80 is spun about its axis of rotation by a DC
servo motor 86 through a belt and pulley mechanism. The belt and
pulley mechanism consists of a pulley 82 connected to scrubber
brush 80, a pulley 88 connected to motor 86, and a belt 84 looped
over pulley 82 and pulley 88. Motor 86 is mounted on scrubber frame
90. Motor 86 is connected to DC servo motor driver in control
subsystem 34, as will be described in further detail below.
[0092] A splash and drip guard 96 extends the length of scrubber
brush 80. Splash and drip guard 96 is rotatably mounted onto
scrubber frame 90 and is rotatable around the axis of rotation of
scrubber brush 80. When splash and drip guard 96 is retracted (as
shown in FIGS. 7 and 9), splash and drip guard 96 prevents cleaning
liquid from a rotating scrubber brush 80 to splash against the
inside of cleaner 10. When in its lowered position (as shown in
FIGS. 8 and 9A), splash and drip guard 96 prevents cleaning
solution from scrubber brush 80 to drip onto the floor.
[0093] The mechanism for lowering and retracting splash and drip
guard 96 includes a geared lip 100 on splash and drip guard 96 and
a gear 102. Gear 102 is driven by a motor 104 (shown in FIG. 10)
which is connected to a DC servo motor driver controlled by control
subsystem 34, as will be described in further detail below. When
motor 104 rotates gear 102, gear 102 causes geared lip 100 and
hence splash and drip guard 96 to rotate about the axis rotation of
scrubber brush 80.
[0094] Referring also to FIG. 11, a cleaning solution dispenser 110
has a trough portion 112 into which cleaning solution is poured
through an opening 114 in scrubber frame 90. A pipe (not shown)
connects opening 114 to vacuum and liquid subsystem 30. Trough
portion 112 of cleaning solution dispenser 110 includes a number of
evenly spaced holes 116 which dispense cleaning solution evenly
onto scrubber brush 80 along its length. Cleaning solution
dispenser 110 also includes an integrated splash guard portion 118
protecting components of cleaner 10.
[0095] Also referring to FIGS. 12, 12A and 13, scrubber assembly 14
also includes a squeegee assembly 120. Squeegee assembly 120 has a
squeegee core 122 that is mounted onto left and right connecting
members 138A-B. Connecting members 138A-B are pivotally mounted on
mounting frame 92. Squeegee core 122 of squeegee assembly 120 has
two key hole shaped grooves 124A-B which extend along the length of
squeegee core 122. Grooves 124A-B are sized and shaped to receive
squeegee blades 126A-B. Squeegee blades 126A-B have an upper
portion which is key shaped and is sized to fit in the key-hole
shaped grooves 124A-B. By key-hole shaped grooves, we refer to a
groove which has a portion that is wider, or differently shaped,
than at least one other portion of the groove, so that a properly
sized and shaped key-shaped component inserted therein will resist
a downward pulling force because of its shape and remains in the
groove. To insert squeegee blades 126A-B into grooves 124A-B,
squeegee blades 126A-B are slid along the length of grooves 124A-B.
It should be noted that squeegee blade 126A, which is the leading
squeegee blade, is ribbed so as to allow cleaning liquid collected
in front of squeegee blade 126A to flow into the space between
squeegee blades 126A-B to be collected by suction from vacuum and
liquid subsystem 30.
[0096] At one end of grooves 124A-B, a cover 128 is bolted on
squeegee core 122 for preventing squeegee blades 126A-B from
sliding out of squeegee core 122. At the other end of grooves
124A-B, a cover 130 is pivotally mounted on squeegee core 122.
Cover 130 is held in place over the groove openings by a spring
loaded ball and detente mechanism 132.
[0097] Squeegee assembly 120 has a pair of wheels 140A-B which are
installed on connecting members 138A-B, respectively. Wheels 140A-B
rest on the floor surface during operation and prevent the weight
of squeegee assembly 120 from crushing squeegee blades 126A-B.
[0098] Referring particularly to FIG. 13, squeegee assembly 120
further includes a vacuum plenum 134 mounted on squeegee core 122.
Vacuum plenum 134 defines a cavity 142 which is continuous with a
cavity 144 in squeegee core 122. Cavity 144 is located between
grooves 124A-B. At the bottom of squeegee core 122, cavity 144 runs
substantially the length of squeegee core 122 and opens into the
space between squeegee blades 126A-B. Plenum 134 further includes a
pipe 136 which connects to a vacuum hose (not shown) which leads to
vacuum and liquid subsystem 30.
[0099] For lifting squeegee assembly 120, a bracket 146 is provided
on squeegee assembly 120. A portion of bracket 146 rests on an
off-center cam 148 which is coupled to a DC servo motor 150 is
connected to a DC servo motor driver controlled by control
subsystem 34, as will be described in further detail below. As
motor 150 rotates cam 148, bracket 146 is lifted thereby lifting
squeegee assembly 120.
[0100] During operation, vacuum and liquid subsystem 30 pumps
cleaning liquid into trough portion 112. The pumped cleaning liquid
falls onto scrubber brush 80 through openings 116 of trough portion
112. Then, scrubber brush 80, wet with cleaning liquid, is lowered
to scrub the floor.
[0101] Suction from vacuum and liquid subsystem 30 creates a
negative air pressure in cavities 142 and 144, and in the space
between squeegee blades 126A-B. This negative air pressure results
in air being removed from the space between the squeegee blades and
in front of the leading squeegee blade 126A. Together with the air,
the cleaning liquid on the floor surface, along with the dirt that
is now in suspension, is also collected.
[0102] Squeegee assembly 120 is located relatively close to
scrubber brush 80. Preferably the distance between the point of
contact of scrubber brush 80 with the floor and the point of
contact of the leading squeegee blade 126A with the floor is less
than about 5 inches. Placing the squeegee assembly 120 relatively
close to scrubber brush 80 results in at least two advantages.
First, it results in making cleaner 10 more compact so as to enable
mounting all of the components necessary for performing three
cleaning operations on a single cleaning apparatus. Second, it
allows squeegee assembly 120 to remove the cleaning liquid
deposited by scrubber brush 80 shortly after it is deposited,
thereby reducing the possibility of trails of cleaning liquid being
left behind.
Vacuum and Liquid Subsystem
[0103] Referring to FIGS. 14, 14A, and 15-16, vacuum and liquid
subsystem 30 includes a liquid recovery tank 190, a filter 192, a
vacuum motor 194, and a fluid pump 196. A hose (not shown) connects
liquid recovery tank 190 to pipe 136 of plenum 134. At liquid
recovery tank 190, the hose connects to an end 198A of a pipe 198.
Pipe 198 at another end 198B opens into the cavity of liquid
recovery tank 190, near the top of liquid recovery tank 190. Liquid
recovery tank 190 is filled such that the cleaning liquid level
always remains below opening 198B of pipe 198. The cleaning liquid
may be water or other cleaning liquids commonly used for scrubbing
floors.
[0104] Vacuum motor 194 is connected to liquid recovery tank 190
through an air inlet 200. Air inlet 200 is capped by a wire mesh
strain 202 which prevents foreign objects, such as hair, from
reaching vacuum motor 194. Air inlet 200 and strain 202 are located
inside a removable clear plastic dome 204. Plastic dome 204 allows
the user to inspect strain 202 visually so as to remove any dirt
collected by strain 202, if necessary.
[0105] Fluid pump 196 is connected to trough 112 (shown in FIG. 11)
through a hose 206. Fluid pump 196 is connected to liquid recovery
tank 190 through filter 192. A fluid valve 196A is located between
fluid pump 196 and filter 192. Some embodiments do not include a
fluid valve. Fluid pump 196 and fluid valve 196A are connected to a
dedicated driver controlled by control subsystem 34, as will be
described in further detail below.
[0106] As vacuum pump 194 operates, a negative pressure is created
in liquid recovery tank 190 resulting in a suction being applied to
pipe 198, and hence to plenum 134 and the space between squeegee
blades 126A-B. The suction creates a flow of an air and now dirty
cleaning liquid mixture collected from the space between squeegee
blades 126A-B and the area in front of the leading squeegee blade
126A. As the flow of air and cleaning liquid mixture enters liquid
recovery tank 190, the speed of the flow suddenly decreases since
the volume in which the mixture can flow suddenly increases. The
sudden decrease in the speed of the flow results in the liquid
separating from the air and falling into the tank. Fluid pump 196
pumps the cleaning liquid in recovery tank 190 through filter 192
which removes the dirt particles in the cleaning liquid.
Burnisher Assembly
[0107] Referring to FIGS. 17, 18 and 19, burnisher assembly 16
includes a burnisher pad 160, a burnisher pad cover 162, a motor
168 and a burnisher linkage assembly 170. Burnisher pad 160 is made
out of porous, non-woven, air-layered fibrous material secured
together with an adhesive binder. Preferably, burnisher pad 160 has
characteristics previously proven suitable for use with commercial
UHS finishes. Burnisher pad 160 is directly connected a DC servo
motor 168 controlled by the control subsystem 34. Motor 168 can
spin burnisher pad at speeds of up to about 3500 and preferably up
to about 2800 rpm, and preferably at about or above 2100 rpm.
[0108] Burnisher pad cover 162 is characterized by a semicircular
groove 164 which has a gradually rising profile. During operation,
as motor 168 spins burnisher pad 160, burnisher pad 160 creates a
spinning air flow which moves upward and carries dust particles
from the floor surface with it. Groove 164 directs this air flow
toward exit opening 166 and into a pipe (not shown) which is
connected to a porous vacuum cleaner filter bag (not shown). The
vacuum cleaner bag collects the dust but allows the air to flow out
of the bag.
[0109] Linkage assembly 170 is a spring loaded four bar linkage.
Linkage assembly 170 includes a burnisher support member 172 and a
mounting frame 174 for connecting burnisher assembly 16 to frame 18
of cleaner 10 (shown in FIGS. 1-2). Linkage assembly 170 includes
four horizontal linkage bars 176, each of which is connected at one
end to burnisher support member 172 and at another end to mounting
frame 174. A pair of coil springs 178A are located at the mounting
frame end of linkage bars 176. Another pair of coil springs 178B
are located at the support member end of linkage bars 176. Coil
springs 178A-B are mounted to resist the downward force exerted by
the weight of burnisher pad 160, burnisher pad cover 162, and motor
168, and to allow burnisher pad 160 to float near the floor
surface.
[0110] To lift and lower burnisher pad 160, burnisher assembly 16
includes a motor 182 connected to a cam 180. Cam 180 engages an
extended portion 184 of support member 172. Motor 182 is connected
to a DC servo motor driver controlled by control subsystem 34, as
will be described in further detail below. As motor 182 rotates cam
180, burnisher pad 160 is either lifted or lowered. Note that the
movement of burnisher pad 160 is substantially vertical. This
substantially vertical movement reduces the extent to which
burnisher pad 160 needs to be lifted so that all points of
burnisher pad 160 have a predetermined clearance from the floor.
Hence, the amount of space required for accommodating burnisher
assembly 16 in its retracted position is less than otherwise may be
the case, thereby making it possible to have components for
performing three cleaning operations on the same cleaning
apparatus.
[0111] We have observed that having burnisher assembly 16 and
scrubber assembly 14 on the same frame results in significantly
improved cleaning results. The present system provides the
advantage of performing multiple operations with a single pass of
cleaner 10 over the floor. We have discovered that combining the
burnishing operation with one or more of the sweeping and/or
scrubbing operations, particularly the scrubbing operation, in a
unitary, coordinated system so that the operations are performed
serially provides certain advantages not previously achieved or
recognized.
[0112] In particular, embodiments of cleaner 10 clean waxed floors
with significantly better luster and shine than when the same
cleaning operations are performed separately, in more than one
pass, at widely spaced intervals as are typically performed by an
operator using separate devices. We currently hypothesize that the
improved results may be because the scrubbing and burnishing
operations are performed closely spaced in time. In other words, it
may be that the burnishing operation provides enhanced results when
it is performed within a short time after the scrubbing operation
resulting in increased gloss.
[0113] If that is the case, a cleaner, comprising a connected
"train" of devices coordinated mechanically or electronically to
perform the cleaning operations in the desired order and in close
proximity in time, may achieve similar results.
[0114] We also currently hypothesize that the improved performance
may be because scrubber assembly 14 when scrubbing the floor
softens the wax or renders it plastic-like. Because burnisher
assembly 16 starts burnishing shortly afterward, the wax is still
in its softened or plastic state. Hence, the results of burnishing
is significantly improved.
[0115] If that is the case, it may be possible to get the same
advantage in other manner, so long as the wax remains in a softened
or plastic state when the floor is burnished. For example, it is
possible to use chemicals which reduce the rate of hardening of the
wax after the scrubbing, resulting in the wax remaining in its
plastic/softened state. Or, it may be possible to place a chemical
on the floor or heat the floor to soften the wax or render it
plastic-like just before burnishing the floor.
Control Subsystem
[0116] Control subsystem 34 receives inputs from the user, and,
based on those inputs, operates cleaner 10. Control subsystem 34
also coordinates among various operations performed by cleaner 10.
We will first describe the circuitry of control subsystem 34. We
will then describe the application programs executed by subsystem
34.
[0117] FIG. 20 is a schematic diagram of the circuitry of control
subsystem 34. Control subsystem 34 receives input signals from
pressure sensing pads 26A-B and the controls on control panel 22
(shown in FIG. 1). These signals are received by a user interface
board 1014. The signals associated with the emergency stop button
and key switch are in addition received by a power distribution
system 1008.
[0118] Power distribution system 1008 includes DC-DC converters
that convert the voltage supply from batteries 32 (e.g., 36 or 48V)
to various voltages required by various components of cleaner 10.
Power distribution system 1008 also includes circuitry for
performing a start-up sequence. During the start-up sequence, power
distribution system 1008 measures the battery voltage and
determines whether correct voltages are output by its the DC-DC
converters. If correct voltages are output, power distribution
system 1008 will turn on the rest of the components of control
subsystem 34.
[0119] Power distribution system 1008 also implements a number of
safety features. For example, in response to an input from the
emergency stop button on control panel 22, power distribution
system 1008 immediately cuts off all power to all components. Power
distribution system 1008 also does not allow cleaner 10 to operate
when housing 20 is not properly attached to frame 18 (FIG. 1).
[0120] A Power monitoring board 1010 monitors the overall power
consumption of cleaner 10, and power consumption of each
subsystem.
[0121] User interface board 1014, in response to signals from
control panel 22 and pressure sensing pads 26A-B, generates
commands to be transmitted to other components of control subsystem
34 through a neuron interface card 1018 connected to a system bus
1026. User interface board 1014 also sends signals to control panel
22 for lighting appropriate status LEDs to indicate to the user
that various requested operations are being performed.
[0122] Control subsystem 34 includes a main processor board 1024
which includes a microprocessor for executing various application
programs for operating cleaner 10. In the described embodiment, the
microprocessor on processor board 1024 is an MC68332 processor
manufactured by Motorola Corporation. Processor board 1024 is
connected to system bus 1026 through a neuron interface board 1016.
Processor board 1024 also includes a memory for storing the
application programs executed thereon.
[0123] Processor board 1024 is also connected to a two-axis motor
controller board 1028 which controls the operation of drive wheel
motors 64. Two-axis motor controller board 1028 receives velocity
control commands with respect to drive wheel motors 64 from
processor board 1024. Two-axis motor controller board 1028
translates the velocity control commands to appropriate DC analog
signals for driving universal motor driver boards 1030-1032, each
of which is respectively connected to one of drive wheel motors 64.
Universal motor driver boards 1030-1032 amplify the received
signals and directly drive motors 64.
[0124] The speed of each one of drive wheels 28A-B is monitored and
controlled by a closed loop velocity control system implemented by
encoders 1034-1036, two-axis motor controller board 1028, and the
application programs running on processor board 1024. Generally,
encoders 1034-1036 send signals corresponding to the speed of
rotation of each one of drive wheels 28A-B to two-axis motor
controller board 1028. Encoders 1034-1036 can be optical or
magnetic encoders. Two-axis motor controller board 1028 translates
the signals from encoders 1034-1036 to appropriate data transmitted
to processor board 1024. The application programs running on
processor board 1024 use the data to ensure that drive wheels 28A-B
are rotating at correct speeds by adjusting the speed commands sent
to two-axis motor controller board 1028, as will be described in
detail below.
[0125] The circuitry of control subsystem 34 also includes a
cleaning actuator board 1038 which receives instructions from
application programs running on processor board 1024 through a
neuron interface card 1022. Cleaning actuator board 1038 includes a
microprocessor and a memory. The memory stores application programs
which in response to the commands from processor board 1024 operate
the various drivers and motors connected to cleaning actuator board
1038. Each one of the motors connected to cleaning actuator board
1038 is driven by a dedicated driver. Drivers for scrubber motor
86, vacuum pump 194, and burnisher motor 168 are not part of
cleaning actuator board 1038. All other motor drivers (designated
as `MD`) are part of cleaning actuator board 1038.
[0126] A plurality of limit switches 1046 are positioned
appropriately on cleaner 10, and are connected to cleaning actuator
board 1038. Each one of limit switches 1046 provides a signal to
cleaning actuator board 1038 when a moving component to which that
limit switch connected reaches a predetermined position. For
example, two limit switches are provided for sweeper assembly 12.
One of those limit switches provides a signal to cleaning actuator
board 1038 when sweeper assembly 12 reaches its lowered position.
Another one of these limit switches provides a signal when sweeper
assembly 12 reaches its retracted position. Similarly, three limit
switches are provided for burnisher assembly 16 to provide
indication of when burnisher assembly 16 reaches any one of its
three positions. Other limit switches provide signals regarding the
two positions of scrubber brush 80, the two positions of squeegee
assembly 120, and the two positions of splash and drip guard 96. In
addition to limit switches 1046, a set of status switches 1048
provide information with respect to whether liquid recovery tank
190 (shown in FIG. 15) is full or empty, and whether hopper 42
(shown in FIG. 5) is missing or is full.
[0127] Having described the circuitry of control subsystem 34, we
will now describe the application programs running on processor
board 1024 and cleaning actuator board 1038. These application
programs generally have a behavior based architecture. Programs
having behavior based architecture are typically used for robotics
applications where a robot is conceptualized as having a number of
interdependent behaviors, that is, behaviors which are in part
independent of one another and in part dependent on one another.
Typically, such programs are designed to have multiple behavior
modules, where each one of the behavior modules is responsible for
implementing one of the behaviors of the robot. All behavior
modules typically run in parallel to one another on a same
processor, or on different processors. Each behavior module can be
thought of as a set of instructions that can be activated or
deactivated based on outputs by other behavior modules or based on
environmental conditions. Typically, there is more than one way for
a behavior module to be activated or deactivated, and the behavior
module can act differently depending on how it is activated or
deactivated. For an overview of behavior based programming see R.
A. Brooks, "The Behavior Language; User's Guide" A.I. Memo 1227,
Massachusetts Institute of Technology--Artificial Intelligence
Laboratory, 1990.
[0128] We have found behavior based programming particularly
suitable for cleaner 10. Cleaner 10 has various subsystems, each of
which performs a particular cleaning function. The operation of
each of these subsystems needs to be controlled partly independent
of the operation of other subsystems and partly dependent on the
operation of the other subsystems. In addition, the operation of
each of the subsystems must be optimized in part independently of
the other subsystems and in part based on the operations of the
other subsystem.
[0129] To understand this, consider the following subsystems of
cleaner 10: scrubber assembly 14, burnisher assembly 16, and drive
wheels 28A-B. These subsystems operate substantially independent of
one another. However, in some respects, their operations depend on
one another. For example, the speed at which burnisher pad 160 is
spun depends on the speed at which cleaner 10 is driven. In
addition, burnisher pad 160 should be preferably placed onto a
particular area of the floor only after cleaner 10 has scrubbed
that area. This minimizes damage to the floor. In the described
embodiment, to ensure that burnisher pad 160 is placed over an
already scrubbed area, burnisher pad 160 is lowered only after
cleaner 10 has traveled a sufficient distance to ensure that
burnisher pad 160 is over an area scrubbed by scrubber assembly 14.
Moreover, to improve cleaning quality, after the operator has
decided to stop scrubbing the floor, cleaner 10 should travel a
sufficient distance so that squeegee assembly 120 removes cleaning
liquid deposited by scrubber brush 80.
[0130] As already stated, behavior based programming allows having
multiple behavior modules running in parallel enabling controlling
and optimizing various subsystems independently of one another. At
the same time, such programming allows coordination of the
operation of various subsystems based on one another. In control
subsystem 34, there are two levels of behavior modules. One set of
behavior modules are high level behavior modules which are executed
by processor board 1024. These behavior modules implement high
level behaviors of cleaner 10 such as driving, sweeping, scrubbing,
and burnishing. A second set of behavior modules are low level
behavior modules which are executed by. cleaning actuator board
1038. These behavior modules implement low level behaviors of
cleaner 10 controlling operations of all of the motors on cleaner
10, except for drive wheel motors 64.
[0131] The high level behavior modules depend on independent and
proper execution of the low level behavior modules. The high level
behavior modules issue commands to the low level behavior modules.
The low-level behavior modules then implement a sequence of steps
to implement the particular, requested behavior. The high level
behavior modules, after issuing commands, do not monitor the
operation of the low level behavior modules and proceed to execute
other steps. After receiving a command, the low level behavior
modules do not require any further input from the high level
behavior modules. In essence, the commands are implemented
according to a "fire and forget" architecture: after issuing a
command, the high level behavior modules can forget about the low
level behavior and assume that it will be implemented. This
architecture allows the high level behavior modules to be optimized
for implementing the high level behaviors rather than for
implementing the low level behaviors. This architecture also allows
optimizing the low level behaviors solely for implementing the low
level behaviors without any concern about the high level
behaviors.
[0132] The low level behavior modules can be categorized and
described based on the type of motors they operate. There are
generally two types of motors in cleaner 10. The first type of
motors operate the various components performing cleaning
operations. These motors are sweeper brush motors 38A-B, scrubber
brush motor 86, vacuum pump 194, fluid pump motor 196, and
burnisher motor 168. The low level behavior modules controlling the
operation of the first type of motors receive commands indicating
that a motor should either start or stop operating. These lower
level behavior modules translate those commands to instructions
required by the corresponding drivers.
[0133] The second type of motors in cleaner 10 retract and lower
various components of cleaner 10. These motors include sweeper lift
motor 58, scrubber lift motor 106, splash and drip guard motor 104,
squeegee lift motor 150, and burnisher lift motor 182. Each one of
the low level behavior modules controlling the operations of these
motors, after receiving a command, provide commands to a
corresponding driver to start the appropriate motor. The behavior
module then monitors signals from corresponding limit switches to
determine when the component has reached the desired position and
then sends commands to stop the motor.
[0134] We will now describe the high level behavior modules in
reference to FIGS. 21-30. FIG. 21, shows a behavior diagram of the
high level behavior modules running on processor board 1024. There
are nine separate behavior modules which run in parallel on
processor board 1024. FIGS. 22-30 are pseudo codes for the steps
taken by these nine behavior modules.
[0135] These nine behavior modules can be divided into three
groups. The first group of behavior modules implement three user
interface and error behaviors: control behavior module 2100,
handles behavior module 2200, and error behavior module 2900. The
second group of behavior modules implement two coordinating
behaviors: enable behavior module 2400 and distance behavior module
2800. The third group. of behavior modules implement four
operational behaviors: sweep behavior module 2500, scrub behavior
module 2600, drive behavior module 2700, and burnish behavior
module 2800.
[0136] Referring to FIG. 22, error behavior module 2900 sets an
ERROR flag when status switches 1048 indicate that hopper 42 is
either missing, or liquid recovery tank 190 is either overflowing
or empty. Error behavior module 2900 also sets the ERROR flag when
there is a system error comprising an electronic detection of a
mechanical problem (step 2902). The ERROR flag causes other
behavior modules to stop all operations on cleaner 10.
[0137] Referring to FIG. 23, control behavior module 2100
translates data corresponding to signals from control panel 22 to
output commands corresponding to the user's selections. These
outputs include commands for commencing or stopping any one of the
cleaning operations and a particular speed selected by the
user.
[0138] Referring to FIG. 24, handles behavior module 2200 first
determines whether the ERROR flag is set (step 2202). If so,
handles behavior module 2200 sets RIGHT-HANDLE and LEFT-HANDLE
variables to values corresponding to signals from left and right
pressure sensing pads 26A-B (steps 2204). If either one of the
RIGHT-HANDLE and LEFT-HANDLE variables is set, handles behavior
module 2200 measures and outputs a TIME-ENABLED variable which
measures the period since when one or both pressure sensing pads
26A-B have been pressed (step 2206). If neither one of pressure
sensing pads 26A-B is pressed, handles behavior module 2200 outputs
a TIME-DISABLED variable which measures the continuous period of
time when neither one of the pressure sensing pads 26A-B has been
pressed (steps 2208). Additionally, if either one of left and right
pressure sensing pads 26A-B is pressed, handles behavior module
2200 sets an ENABLED flag (step 2210).
[0139] If the ERROR flag is set (step 2202), handles behavior
module 2200 sets the ENABLED, RIGHT-HANDLED, LEFT-HANDLED,
TIME-ENABLED, and TIME-DISABLED variables to false (steps
2212).
[0140] Referring to FIG. 25, enable behavior module 2400 implements
a coordinating behavior and is responsible for setting a
DRIVE-ENABLED flag which determines whether drive wheel motors 64
can operate drive wheels 28A-B. Enable behavior module 2400 sets
the DRIVE-ENABLED flag when three conditions are met. First, the
ENABLED flag must be set by handles behavior module 2200. Second,
sweeper brushes 36A-B must be either in their retracted or lowered
positions. Third, scrubber brush 80 must be either in its retracted
or lowered position. When all three conditions are met, enable
behavior module 2400 sets the DRIVE-ENABLED flag. Enable behavior
module 2400 thereby prevents movement of cleaner 10 when pressure
sensing pads 26A-B are not being pressed, sweeper brushes 36A-B are
in the process of being retracted or lowered, or scrubber brush 80
is in the process of being retracted or lowered.
[0141] Referring to FIG. 26, sweep behavior module 2500 implements
the sweeping behavior of cleaner 10. If the SWEEP-CMD flag is set,
the SPEED variable is not set for reverse speed, and the ERROR flag
is not set (step 2502), sweep behavior module 2500 provides
commands to turn on sweeper brush motors 38A-B and to lower sweeper
brushes 36A-B (steps 2504). Sweep command behavior module 2500
starts sweeper brush motors 38A-B only after the value of the
TIME-ENABLED variable is greater than a predetermined
DELAY-ON-SWEEP-START constant. Similarly, sweep command behavior
module 2500 sends the command for lowering sweeper brushes 36A-B
only after the TIME-ENABLED variable is greater than a
predetermined DELAY-ON-SWEEP-LOWER constant. These delays ensure
that sweeping does not begin until after the operator has applied
pressure to pressure sensing pads 26A-B for a predetermined period
of time. Sweep command behavior module 2500 also sets a SWEEPING
flag indicating that the cleaner 10 has begun sweeping the floor
(steps 2506).
[0142] If the TIME-DISABLED variable is greater than a
DELAY-OFF-SWEEP-RAISE constant, indicating that the user has
removed his hands from pressure sensing pads 26A-B for more than a
predetermined period of time, sweep behavior module 2500 stops
sweeping operation by first raising sweeping brushes 36A-B (steps
2508). After a further delay determined by a DELAY-OFF-SWEEP-STOP
constant, sweep behavior module 2500 stops sweeping brush motors
38A-B (steps 2510). These delays ensure that cleaner 10 continues
to sweep, even when the operator removes his hands from the
pressure sensing pads 26A-B momentarily. At the same time, stopping
the sweeping (and other operations, as will be described below)
ensures that cleaner 10 does not operate unless there is an
operator present. This is an important "time out" safety feature of
cleaner 10.
[0143] If the SWEEP-CMD flag is not set, the SPEED variable is set
for reverse speed, or the ERROR flag is set (step 2502), then sweep
behavior module 2500 stops cleaner 10 from sweeping immediately and
sets the SWEEPING flag to false (steps 2512).
[0144] Referring to FIG. 27, scrub behavior module 2600 implements
scrubbing behavior of cleaner 10. If the SCRUB-CMD flag is set, the
SPEED variable is not set for reverse, and the ERROR flag is not
set, then scrub behavior module 2600 determines whether the
TIME-ENABLED variable is greater than a predetermined
DELAY-ON-SCRUB-START constant indicating that the user has applied
pressure to pressure sensing pads 26A-B for a sufficiently long
time for cleaner 10 to start scrubbing (step 2602). If so, scrub
behavior module 2600 issues commands for retracting splash and drip
guard 96, starting scrubber brush motor 86, starting vacuum pump
194, lowering squeegee assembly 120, and opening fluid valve 196A
(steps 2604). If scrub behavior module 2600 determines that the
TIME-ENABLE variable is greater than a further
DELAY-ON-SCRUBBER-LOWER constant, scrub behavior module 2600 starts
fluid pump 196, lowers scrubber brush 80, and sets a SCRUBBING flag
to indicate that cleaner 10 is scrubbing the floor (steps
2606).
[0145] If scrub behavior module 2600 determines that the
TIME-DISABLE variable is greater than a predetermined
DELAY-OFF-SCRUBBER-RAISE constant, indicating that the user has
stopped applying pressure to pressure sensing pads 26A-B, scrub
behavior module 2600 stops cleaner 10 from scrubbing (steps 2608).
To do so, scrub behavior module 2600 first determines whether the
TIME-DISABLED variable is greater than a DELAY-OFF-SCRUBBER-RAISE
constant. If so, scrubber brush 80 is lifted, the SCRUBBING flag is
set to false, and fluid pump 196 is shut off. If scrub behavior
module 2600 then determines that the TIME-DISABLED variable is
greater than a predetermined DELAY-OFF-SCRUBBER-STOP constant,
scrub behavior module 2600 shuts off scrubber brush motor 86, and
closes fluid valve 196A (steps 2610). Scrub behavior module 2600
then proceeds to lower splash and drip guard 96, raise squeegee
assembly 120, and turn off vacuum pump 194, but only after
determining that a SQUEEGEE-SAFE flag is set. The SQUEEGEE-SAFE
flag indicates whether squeegee blades 126A-B have traveled a
sufficient distance to remove the cleaning liquid deposited by
scrubber brush 80 before it was lifted (steps 2612). The
SQUEEGEE-SAFE flag is set by distance behavior module 2800, as will
be described below.
[0146] If the SCRUB-CMD flag is not set, the SPEED variable is set
to reverse, or the ERROR flag is set, scrub behavior module 2600
stops cleaner 10 from scrubbing without any delay. To do so, scrub
behavior module 2600 sends commands to raise scrubber brush 80, set
the SCRUBBING flag to false, shut off fluid pump 196, turn off
scrubber brush motor 86, and close fluid valve 196A (steps 2614).
If the SPEED variable is set to reverse or the ERROR flag is set,
scrub behavior module 2600 also sends commands to lower splash and
drip guard 96, raise squeegee assembly 120, and turn off vacuum
pump 194 (steps 2616). Otherwise, these steps are taken only after
the SQUEEGEE-SAFE flag is set indicating that squeegee assembly 120
has traveled over an area cleaned by scrubber brush 80 and hence
has removed the cleaning liquid deposited by scrubber brush 80 on
the floor.
[0147] Referring to FIG. 28, drive behavior module 2700 implements
the driving behavior of cleaner 10 by controlling the operation of
drive wheels 28A-B of cleaner 10. To do so, drive behavior module
2700 implements two functions. First, drive behavior module 2700
monitors and adjusts the speed of drive wheels 28A-B to ensure that
they track a speed selected by the user. Second, drive behavior
module 2700 controls the direction of travel of cleaner 10.
[0148] To implement the first function, drive behavior module 2700
compares the current speed of each one of drive wheels 28A-B to the
speed selected by the user. As discussed above, the current speed
is measured by encoders 1034-1036 (shown in FIG. 20). If the
current speed of either one of drive wheels 28A-B is not the same
as the speed selected by the user, drive behavior module 2700
adjusts the speed of that drive wheel to more closely track the
selected speed (steps 2702). As mentioned above, in this manner, a
closed-loop velocity control of drive wheels 28A-B is implemented
in cleaner 10.
[0149] To implement the second function, drive behavior module 2700
controls the speed of drive wheels 28A-B individually to move
cleaner 10 forward and backward, turn cleaner 10 to the left or
right, and stop cleaner 10. To implement a left turn, drive
behavior module 2700 stops left drive wheel 28B from rotating and
allows right drive wheel 28A to continue to rotate. To implement a
right turn, drive behavior module 2700 stops right drive wheel 28B
from rotating and allows left drive wheel 28A to continue to
rotate. To stop cleaner 10, drive behavior module 2700 stops both
drive wheels 28A-B. To move cleaner 10 forward or in reverse in a
straight line, drive behavior module 2700 rotates both drive wheels
28A-B at the same speed and in the same direction.
[0150] We will now describe the specific manner in which drive
behavior module 2700 implements the above method of directional
control. First, drive behavior module 2700 determines whether the
DRIVE-ENABLED flag is set and the ERROR flag is not set (step
2704). Then, if the user is pressing left pressure sensing pad 26B,
drive behavior module 2700 sets speed of right drive wheel 28A to
the speed selected by the user (steps 2706). If the user is not
pressing left pressure sensing pad 26B, drive behavior module 2700
sets speed of right drive wheel 28A to zero causing the right drive
wheel to stop (steps 2708). In a similar fashion, if the user is
pressing right pressure sensing pad 26A, drive behavior module 2700
sets speed of left drive wheel 28B to the speed selected by the
user (steps 2710). If the user is not pressing right pressure
sensing pad 26B, drive behavior module 2700 sets speed of left
drive wheel 28B to zero causing the left drive wheel to stop (steps
2712). If either one of the left and right pressure sensing pads
26A-B is being pressed, drive behavior module 2700 sets the DRIVING
flag to true (steps 2714). If neither one of the pressure sensing
pads 26A-B is being pressed, drive behavior module 2700 sets the
DRIVING flag to false (steps 2716). In this case, drive behavior
module 2700 also sets the speed of both wheels to zero, thereby
stopping cleaner 10 (steps 2718).
[0151] Referring to FIG. 29, distance behavior module 2800
implements a coordinating behavior for coordinating among scrub
behavior module 2600, drive behavior module 2700, and burnish
behavior module 2900. Generally, distance behavior module 2800
ensures that burnishing does not begin until cleaner 10 has
traveled a sufficient distance to be located over an area already
scrubbed by scrubber assembly 12. Distance behavior module 2800
also ensures that squeegee blades 126A-B are not lifted from the
floor until cleaner 10 has traveled a sufficient distance for
squeegee assembly 120 to remove the cleaning liquid deposited by
scrubber brush 80. To implement these functions, drive behavior
module 2800 supplies flags to scrub behavior module 2600 and
burnish behavior module 2900 to either prevent from performing
their particular cleaning operations, or allow them to perform
their cleaning operations.
[0152] Distance behavior module 2800 first determines whether
scrubber assembly 12 is scrubbing (step 2802). If so, distance
behavior module 2800 calculates the distance traveled by cleaner 10
based on the actual speeds of the left and right drive wheels 28A-B
determined by readings from encoders 1034-1036, and rate of
velocity updates (steps 2804). In alternative embodiments, the
distance can be estimated by a predetermined time constant, or by
the speed selected by the user rather than the actual speed. If
Distance behavior module 2800 determines that the SCRUBBING flag is
false, indicating that scrubber assembly 12 is not currently
scrubbing, distance behavior module 2800 sets a BURNISH-DISTANCE
variable to false, thereby preventing burnish behavior module 2800
from starting the burnishing.
[0153] If distance behavior module 2800 determines that the
SCRUBBING flag is set, then distance behavior module 2800 sets
SQUEEGEE-DISTANCE and SQUEEGEE-TIME variables to false (steps
2806).
[0154] If Distance behavior module 2800 determines that the
SCRUBBING flag is not set and the SQUEEGEE-DISTANCE variable is
false, indicating that scrubber assembly just finished scrubbing,
then Distance behavior module 2800 sets the SQUEEGEE-DISTANCE
variable to zero (steps 2808). The SQUEEGEE-DISTANCE variable
indicates the distance cleaner 10 travels from the time scrubber
assembly 12 stops scrubbing. Distance behavior module 2800 also
sets the SQUEEGEE-TIME variable to the appropriate time when
squeegee blades 126A-B must be lifted off the floor, if not already
lifted (step 2810).
[0155] If the SCRUBBING flag is not set and the SQUEEGEE-DISTANCE
variable is not false, distance behavior module 2800 determines
that scrubber assembly 12 has finished scrubbing and distance
behavior module 2800 is in the process of measuring the distance
traveled by cleaner 10 since scrubbing stopped. Hence, distance
behavior module 2800 calculates the distance based on the actual
speeds of left and right drive wheels 28A-B determined by readings
from encoders 1034-1036, and rate of velocity update (steps 2812).
Distance behavior module 2800 then determines whether the
SQUEEGEE-TIME variable has been set, indicating that scrubber
assembly 12 has finished scrubbing (step 2814). If so, distance
behavior module 2800 determines whether cleaner 10 has traveled a
sufficient distance or whether sufficient time has passed, so that
squeegee blade 126A-B should be lifted anyway (steps 2816).
Distance behavior module 2800 then sets the SQUEEGEE-SAFE flag
accordingly (steps 2818). As described above, SQUEEGEE-SAFE flag is
used by scrub behavior module 2700 to determine whether to lift
squeegee blades 126A-B.
[0156] Next, distance behavior module 2800 determines whether
cleaner 10 has traveled sufficient distance for burnisher assembly
16 to begin burnishing (step 2820). Distance behavior module 2800
sets a BURNISH-SAFE flag accordingly (steps 2822).
[0157] Referring to FIG. 30, burnish behavior module 2900
implements burnishing behavior of cleaner 10. If a BURNISH-CMD flag
is set, the SPEED variable is not set for reverse, and the ERROR
flag is not set (steps 2902), then burnish behavior module 2900
determines whether the TIME-ENABLED variable is greater than a
predetermined DELAY-ON-BURNISH-START constant. If the TIME-ENABLED
variable is greater that the DELAY-ON-BURNISH-START constant,
burnish behavior module 2900 determines that the user has applied
pressure to pressure sensing pads 26A-B for a sufficiently long
time for cleaner 10 to start burnishing. Burnish behavior module
2900 then issues a command to start burnisher motor 168 (steps
2902). Note that burnisher motor 168 spins at different speeds,
depending on the speed of cleaner 10 selected by the user. If the
BURNISH-SAFE flag and the DRIVING flag are set, burnish behavior
module 2900 sends a command for lowering burnisher pad 160 to the
floor and sets a BURNISHING flag (steps 2906). Otherwise, burnish
behavior module 2900 retracts burnisher pad 160 to its intermediate
position (steps 2908).
[0158] If burnish behavior module 2900 determines that the
TIME-DISABLE variable is greater than a predetermined
DELAY-OFF-BURNISHER-STOP constant, indicating that the user has
stopped applying pressure to pressure sensing pads 26A-B, burnish
behavior module 2900 stops cleaner 10 from burnishing (steps 2910).
To do so, burnish behavior module 2900 sends a command to retract
burnisher pad 160 to its intermediate position, sets the BURNISHING
flag to false, and turns off burnisher motor 168 (steps 2910).
[0159] If burnish behavior module 2900 determines that the
TIME-DISABLE variable is greater than a predetermined
DELAY-OFF-BURNISHER-RAISE constant, burnish behavior module 2900
sends a command to retract burnisher pad 160 completely (steps
2914).
[0160] If BURNISH-CMD is not set, the SPEED variable is set to
reverse, or the ERROR flag is set, then burnish behavior module
2900 stops cleaner 10 from burnishing immediately without delay. To
do so, burnish behavior module 2900 retracts burnisher pad 160
completely, sets BURNISHING flag to false, and turns off burnisher
motor 168.
[0161] In this way, the operation of cleaner 10, FIG. 1 and each of
the primary components thereof, namely drive wheels 28A-B, FIG. 2;
sweeper assembly 12; scrubber assembly 14 including vacuum 194,
FIG. 15; squeegee assembly 126A-B, FIG. 7, and fluid pump 196, FIG.
15; and burnisher assembly 16, FIG. 1 is greatly simplified by the
implementation and architecture of control system 34, FIG. 20.
[0162] Without such a control system, the user, to begin cleaning a
floor, would be required, inter alia, to engage drivewheels 28A-B,
FIG. 2, lower sweeper assembly 12, engage sweeper motors 38A-B,
lower scrubber assembly 14 and squeegee assembly 12, engage
scrubber motor 86, FIG. 8, turn on vacuum pump 194, FIG. 15 and
fluid pump 196, and then lower burnisher assembly 16, FIG. 2 and
activate burnisher motor 168, FIG. 17 to rotate burnisher pad
160.
[0163] Each time the cleaner is stopped, the user would then be
required to reverse this process.
[0164] As such, although cleaner 10 uniquely includes three
cleaning heads, control system 34 or its equivalent is highly
desirable: otherwise the operational requirements of cleaner 10
would be overly complex.
[0165] In this invention, control system 34 renders the operation
of cleaner 10 nearly autonomous to the extent that cleaning is
effected by the user issuing only two commands and, conversely, the
cleaning apparatus automatically ceasing to operate, when the user
issues only one command, without damaging the floor and without
leaving cleaning fluid on the floor.
[0166] In operation, the user typically enters a cleaning mode
command via control panel 22 and touches one or both of pressure
sensing pads 26A-B, FIG. 1.
[0167] Control system 34, FIG. 20 then automatically signals drive
motor 64, FIG. 2 to turn drivewheels 28A-B, signals motors 38A-B to
turn sweeper brushes 36A-B, provides signals to sweeper assembly 12
motor 58, FIG. 5 which lowers hopper 42 and sweeper brushes 36A-B,
signals scrubber brush 80 motor 86, FIG. 14 which, in response,
spins scrubber brush 80, provides signals to motor 106 to lower
scrubber brush 80 and squeegee assembly 126A-B, signals motor 104,
FIG. 10 to rotate splash guard 96, FIG. 9A, provides signals to
vacuum pump 194, FIG. 15 and fluid pump 196 to turn them on,
signals burnisher motor 168, FIG. 17 to rotate burnisher pad 160,
and finally, signals burnisher assembly 16 motor 182 to lower
burnisher assembly 16, FIG. 2.
[0168] Preferably, control system 34, FIG. 20 performs these
operations automatically in the sequence listed above but this
particular sequence is not a limitation of the present invention.
Indeed, once the drive wheels begin to turn, all of the cleaning
heads may begin to rotate and all of the cleaning assemblies
lowered at the same time as the vacuum pump and the fluid pump are
energized.
[0169] When the operator removes his hands from both sensing pads
26 A-B, FIG. 1, enters any mode command other than the cleaning
mode command, and/or if an error flag is detected, control system
34 essentially reverses the sequence of operations listed above
except that, in the preferred embodiment, signals are first
provided to turn fluid pump 196 off before vacuum pump 194 is
turned off, before squeegee assembly 120 is raised, before
burnisher assembly 16, scrubber assembly 14, and sweeper assembly
12 are raised, and before the operation of burnisher pad 160,
scrubber brush 80, and sweeper brushes 36A-B stops.
[0170] Typically, at least vacuum pump 194 remains on and squeegee
assembly 120 lowered for the deceleration period of cleaner 10.
[0171] In this way, control system 34 greatly simplifies the
operation of cleaner 10 and, at the same time, insures that the
floor is not damaged and/or that cleaning fluid is not left on the
floor.
[0172] Although control system 34 is described above with respect
to a cleaner with three cleaning heads, control system 34 could be
modified accordingly and implemented in a cleaner with only a
scrubbing brush or pad and a burnishing pad or pads. Moreover,
although a behavior based architecture is described, control system
34 could be implemented using different software algorithms or even
electronic circuitry without processors. Accordingly, control
system 34 and its associated circuitry could be implemented based
on microprocessor software algorithms including but not limited to
behavior based architectures or based on analog or digital
circuitry architectures.
[0173] While not intending to be bound by any particular
explanation for the phenomena resulting from the practice of the
present invention, it is believed that a combination of factors may
be contributing to the surprising results achieved by the present
invention. It is known that some polymeric coatings are hydrophilic
in character and tend to absorb some water on contact. Typically
the repair of the surface of the coating involves primarily a thin
region near the surface of the coating. Performing the burnishing
closely in time after the scrubbing may permit the burnishing to
occur while the surface region of the polymeric coating contains
some absorbed wash water. At this time, the surface of the coating
may be temporarily in a softened, malleable plastic state as a
result of absorption of a portion of the washing liquid. This
effect may be enhanced with particularly hydrophilic coatings or by
the use of surfactants or other additives added to the washing
liquid. The liquid begins to evaporate into the air from this thin
surface zone quickly after the bulk liquid is removed form the
surface so that in conventional practice the burnishing operation
is performed after the coating has already dried and hardened. In
the dry state, the coating is more frangible or friable and is
subject to creation of scratches. However, while the coating
contains a substantial amount of the additional, absorbed liquid it
may temporarily be in a softer and more malleable state and is more
likely to flow and be deformed or displaced rather than scratched
or broken. This may result in a smoother surface being created by
the burnishing operation. Thus, it is a feature of the method and
device of the present invention that the burnishing take place
while the coating contains a significant amount of additional water
and before it has transitioned back to the hard, dry state. A
squeegee, vacuum or other mechanism is located following the
scrubber to remove bulk water from the surface of the floor after
scrubbing and before burnishing. Because the coating begins to dry
after the bulk water is removed from the surface, it is desirable
that the burnisher be placed as close as practical after the point
where the bulk surface water is removed. Also, it is preferred that
the bulk liquid removal point be located so that the water will
have sufficient time to penetrate the coating before removal. A
device according to the present invention will generally have the
burnishing mechanism within about 10 to about 40 cm of the rear of
the scrubbing mechanism. Preferably the leading edge of the
burnishing mechanism is within about 25 cm from the point of bulk
liquid removal and preferably within about 10 cm.
[0174] The cleaning machine according to the present invention will
often traverse the floor at the rate of about 45-55 cm per second.
The placement of the burnisher closely following the scrubber in
the device of the present invention will ensure that the burnishing
takes place within about three quarters of a second after
completion of scrubbing and less than about one-half second after
the removal of bulk liquid while the coating still contains
substantial absorbed water and is still in the softened, plastic
state when burnished. This will also ensure that the device is
small enough to operate in the intended cleaning environment.
[0175] Yet another factor that may contribute to the surprising
results of the present invention is the use of a relatively soft
brush as the main scrubbing element. The scrubbing pads in
conventional scrubbers are generally nonwoven pads which are quite
aggressive in order to clean the coating and in so cleaning they
remove a portion of the coating leaving it in a "damaged" state,
e.g., having lower gloss than before the scrubbing operation. It is
counterintuitive to expect a softer brush would provide improved
floor coating maintenance. However a softer, bristled brush appears
to clean effectively yet cause relatively little loss of gloss in
the polymer coating. This results in the burnisher having to do
less work to "repair" the damage caused by the scrubbing. As a
result, the burnisher can achieve a higher level of gloss with a
given amount of energy input. The use of a cylindrical, bristled
brush is the preferred scrubbing element in the practice of the
present invention. A cylindrical brush permits the construction of
a more compact cleaning device. Further, performance is enhanced
because such a brush causes substantially linear striations in the
floor coating rather than the random striations caused by a
rotating, circular non-woven pad as is conventionally used. It
appears that these linear striations may result in a surface that
is more readily burnished to a high level of gloss.
[0176] The preferred brushes for use in the present invention are
brushes having polymeric bristles, such as polypropylene or nylon
bristles. The bristles typically range from about 0.1 mm to about
0.5 mm in diameter and most preferably from about 0.15 mm to about
0.35 mm. If they are substantially thicker, they are too stiff to
give the best results in the present invention. If they are
substantially thinner than 0.1 mm, the bristles do not have
sufficient body to clean effectively.
[0177] The burnishing pad useful in the practice of the present
invention can be any of the non-woven, polymeric, for example
nylon, burnishing pads that are commonly used. A preferred pad is a
nylon pad sold by ETC of Henderson, Inc. of Henderson, N.C. under
the designation "Blue Jay".
[0178] In the practice of the present invention it has been found
that an acrylic floor coating can be cleaned and burnished with
good effect by the use of the Multi-operation cleaning device and
method of the present invention when compared with a conventional
scrubbing and burnishing operation. As shown in the Table below a
floor cleaning method and device having sweeping, scrubbing and
burnishing mechanisms on a single platform according to the present
invention (Example "A") was compared with a conventional process
using an autoscrubbing machine and propane-powered burnishing
device (Example "B"). The device of the present invention (Example
"A") was used with a cylindrical soft, polymeric bristled brush
having bristles about 0.35 mm in diameter and rotating at 900 rpm.
The machine was tested with two different burnishing pads. The
first was a conventional, nonwoven, nylon fiber burnishing pad
available commercially from ETC corporation and identified as a
"Blue Jay" pad. rotating at 2100 rpm. The machine was also tested
using a second type of burnishing pad that has been shown to give
the best results with the conventional propane burnisher. The
device was constructed such that the front of the burnishing pad
was located about 20 cm behind the rear point of contact of the
scrubbing brush with the floor.
[0179] The floor finish was an acrylic floor finish liquid
available under the Premia brand, a widely used acrylic polymer
floor finish commercially available from Johnson Wax Professional
of Sturtevant, Wis. The washing liquid was Accumix UHS cleaner also
commercially available from Johnson Wax Professional and used at a
dilution of 1 ounce per 8 gallons of water (1 part cleaner per 1024
parts water).
[0180] The conventional equipment (Example "B") was a conventional
sweeping and scrubbing machine using a nylon bristle scrubbing pad
(Red pad) widely used in the industry and using the same scrubbing
liquid as identified above. The burnisher was a conventional 27
inch (69 cm) propane burnisher manufactured by A.L. Cook and using
the same Gorilla Lite burnishing pad as used on the device of the
present invention and rotated at 2000 rpm. The test floor was first
scrubbed to simulate the wear of normal traffic and to provide a
base line gloss measure and then the test was performed. The test
floor was then scrubbed in the conventional manner with an
autoscrubber using red pads traversing the floor at a speed of 1.5
feet per second (46 cm per sec). After waiting one-half hour after
scrubbing (which is a representative delay experienced when a
single operator first scrubs and then burnishes a reasonable sized
floor) the floor was then burnished with the propane burnisher
moving at the rate of about 2 feet per second (61 cm per second).
The gloss was measured using a Gardner 20 degree gloss meter and
the readings are shown in the Table below. Separately, the test
floor was again scrubbed to establish a baseline and then scrubbed
and burnished with the cleaning device of the present invention
traversing the floor at the rate of 1.7 feet per second (52 cm per
second). The averaged measurements are shown in the Table.
1 TABLE 20 DEGREE GLOSS MEASUREMENT Same Pads--Test 1 Unique
Pads--Test 2 Example "A" Baseline 32 26 Final Gloss 71 77 Increase
39 51 Example "B" Baseline 31 25 Final Gloss 64 57 Increase 33 32
Test 1 = Both burnishers using "Gorilla Lite" pads Test 2 = Propane
Burnisher using Gorilla Lite pad and Example "A" using "Blue-Jay"
pad.
[0181] These tests show that the 20 degree gloss is 5 to 10 points
higher using the method and device of the present invention
(Example "A") compared to a conventional scrubbing and burnishing
operation (Example "B"). This result is true even in Test 1 where
the burnishing pad which performs best in the conventional propane
burnisher is used in both machines. Test 1 shows that the increase
in gloss above the baseline by the method and device of the present
invention is 6 points better than the conventional process. In Test
2 where the best pad for each burnisher is used, the device of the
present invention obtained 51 points increase in gloss versus 32
points increase for the conventional process and achieved a gloss
rating of 77 versus 57 for the conventional process.
[0182] It is to be understood that while the invention has been
described in conjunction with the detailed description thereof, the
foregoing description is intended to illustrate and not limit the
scope of the invention, which is defined by the scope of the
appended claims. Other aspects, advantages, and embodiments are
within the scope of the following claims.
* * * * *