Note: Descriptions are shown in the official language in which they were submitted.
~2~S~7
APPARATUS AND METHOD FOR FABRIC CLEANING WITH FOAM
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to an apparatus and
method for cleaning fabric surfaces. More particular-
ly, the invention relates to a method and apparatus forfoam cleaning upholstery fabrics.
Foam cleaning agents have been used to clean
fabrics, especially carpets, for many years. While it
is possible to perform foam cleaning operations manual-
ly, it takes less physical exertion and, therefore, isnormally preferable to utilize an apparatus which will
assure even application and removal of foam along with
moderate agitation of the fabric prior to removal of
~ the foam. Many such apparatus have been attempted to
remove the foam as soon as possible after application
to prevent overwetting the fabric which can result in
shrin~age, browning, mildew, and excessive drying times.
The prior designs included for example U.S.
Patent No. 3,392,418 to Schowalter, which discloses a
self-contained carpet cleaning apparatus in which foam
is generated through the utilization of a pressurized
air stream acting upon a detergent feed tube. The
detergent is fed to the tube under the force of ~ravity.
The mixture of the air and droplets of detergent produces
a foam. The foam is permitted to drop downwardly from
a screen, through slots, onto a cylindrical, rotating
~1
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--2--
brush. The brush is disposed transversely across the
apparatus, parallel to the floor, so that the rotation
of the brush conveys the foam to the carpet and agitates
the carpet. The foam is subse~uently removed by a vacuum
slot positioned to the rear of the brush.
There are several drawbacks with designs such
as those disclosed in the Schowalter patent. First, a
heavy, bulky rnachine is only suitable for cleaning carpets
and not upholstery and other fabrics. A second disadvantage,
even with respect to carpet cleaning, is that the foam
is applied to the fabric (i.e. carpet) by means of the
rotating brush, which simultaneously agitates the fabric.
Not only are the scrubbing brushes often too harsh on
many fabrics, including the pile of standard carpets,
but the scrubbing action of the brushes drives dirt
particles and the foam down deeper into the fabric making
recovery more difficult. The deeply penetrated foam
dissipates and makes the fabric wetter. These two con-
ditions result in longer drying times and possible over-
wetting. Finally, the amount of foam that is appliedto the carpet is directly related to the speed at which
the operator pushes the machine over the carpet. Thus,
it is difficult to ensure that an even and consistent
layer of foam is applied to the carpet which may result
in uneven cleaning of the fabric.
U.S. Patent Mo. 3,751,755 to Smith discloses
a hand-held, combination vacuum and foam applicator
which also has a number of shortcomings in cleaning
upholstery fabrics. First, it does not apply the foam
and vacuum simultaneously; rather, the foam and vacuum
are independently operated at alternate times. Thus,
this apparatus is highly susceptible to overwetti.ng
while the foam saturates into the fabric during ap-
plication. Moreover, in this apparatus, the foam is
generated remote from the point of application and must
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--3--
be transported a considerable distance to the applicator.
It is inherently difficult to maintain the consistency
of foam under transport because it tends to collapse
during travel.
Due to the above-described problems in the
generation, application, and removal of foam frorn fab-
rics, especially upholstery, other cleaning devices
have been designed that use liquid cleaning agents.
These apparatus are commonly referred to in the indus-
try as "steam" cleaners. For example, U.S. Patent No.
4,083,077 to Knight et al. discloses a hand tool asso-
ciated with a steam cleaning machine for cleaning car-
pets as well as upholstery and other fabrics. The hand
tool embodies a generally hollow head defining a clean-
ing agent chamber with a bottom opening and a vacuumchamber with a bottom opening positioned forward of the
cleaning agent chamber. The operator squeezes the
trigger to release a fluid solution to the cleaning
agent chamber where it is sprayed into the pile of the
underlying fabric. As the operator pulls the hand tool
in the direction of the cleaning agent chamber, suction
from the vacuum chamber is applied to remove the mois-
ture previously sprayed onto the fabric.
One disadvantage of such a steam cleaning
system is that the fluid spray exerts virtually no
force to the fabric pile to loosen embedded soil to be
removed, save for its initial momentum of the spray.
Moreover, an inherent problem with stearn cleaning
systems is overwetting. When cleaning liquid is brushed,
sprayed, or otherwise deposited on a fabric, it tends
to penetrate deeply into the pile. Once the cleaning
liquid has penetrated into the fabric, it is difficult
to remove. Also, in passing through the upper layers
of the fibers, the liquid tends to absorb dirt and carry
it down to the lower layers, where it remains. This
_4- ~Z~S9~7
minimizes the amount of dirt that can actually be removed
from the carpet, and can result in color running, shrinkage,
mildew and browning. Another shortcoming of all liquid
(steam) cleaning operations is that they require sub-
stantial drying times, which is a serious disadvantage,particularly in commercial establishments.
In addition to being subject to all the afore-
mentioned problems of steam cleaning systems, the
apparatus disclosed in the Knight patent is also prone
to localized overwetting around the edges of an up-
holstered object. That is, where the liquid spray pre-
cedes the suction over the edge of a surface, areas on
adjacent surfaces of the object will be wetted but will
not be vacuumed.
The present invention responds to the draw-
backs and limitations of the prior art by providing a
fabric cleaning apparatus which generates foam in one
end of the apparatus and directs it toward the fabric
to be cleaned. In the preferred embodiment of the in-
vention, the foam is generated by admi~ing pressurized
air and a cleaning solution in the apparatus adjacent
to the point of application. The pressurized air also
directs the foam towards the fabric. A vacuum is simul-
taneously provided at the other end of the apparatus,
~5 such that it cooperates with the inertia of the foam to
move the foam rapidly and continuously between the ends
of the apparatus and effectively to produce a continuous
belt of foam between the two ends. It is preferred to
position a stationary brush between the two ends so
that the moving foam passes over and through the bristles
of the brush. When the apparatus is applied to a fabric
to be cleaned, the foam moves in immediate contact with
the fab~ic, and a partial pressure is created that en-
hances the agi~ating action of the foam.
54(~7
-4A-
In one broad aspect, the invention comprehends a fabric
cleaning apparatus havlng front and back ends, comprising means,
adjacent one of the ends, for continusouly generating foam with
positive pressure, and means for continuously propelling the foam
undar positive pressure from the foam generating means out of the
cleaning apparatus towards the fabric to be cleaned. Vacuum
means is adjacent the other end, for continuously and
concurrently removing foam from the fabric. The propelling means
and vacuum means cooperate to move the foam rapidly and
continuously between the front and back ends of the apparatus
without rotating brush means and, when the moving foam is
continuously applied to the surface of a fabric, foam bubbles
will compress under the positive pressure applied by the
propelling means and resistance provided by the fabric, and
expand under the vacuum means, so that the foam moves across the
fabric rapidly, continuously, and under partial pressure.
Another aspect of the invention pertains to a method
for cleaning fabric comprising continuously generating foam under
positive pressure at a point adjacent to the fabric to be
cleaned, continuously propelling the foam under positive pressure
against the fabric to be cleaned so that foam bubbles compress
against the fabric under the positive pressure, continuously and
concurrently removing the foam from the fabric by suction so that
the foam bubbles expand under the negative pressure of the
suction, and moving the foam rapidly and continuously across the
surface of the fabric between the point of foam generating and
suction and under partial pressure resulting from the continuous
positive pressure on the foam and the suction, and without
rotating brush means.
D
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Thus, in the present invention, the rapidly,
continuously moving foam, under partial pressure, in
immediate contact with the surface of the fabric over-
comes many of the disadvantages of the prior art.
Specifically, the force of the moving foam erodes and
suspends embedded soil instantly, thereby providing
improved cleaning. The stationary brush cooperates
with the moving foam to further agitate the fabric and
foam but without the harsh effect on the fabric of a
rotating brush. Moreover, the foam moves rapidly
through the horizontal plane of the fabric so that it
does not penetrate deeply into the pile of the fabric.
This affords easy removal of the foam and minimizes
overwetting. Also, a more consisten-t foam is applied
to the fabric because the foam is generated by admixing
pressurized air and a cleaning solution in the ap-
paratus adjacent to the point of application.
These and other features and advantages of
the present invention will be apparent from the follow-
ing description, appended claims, and annexed drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodi-
ment of the present invention;
FIG. 2a is a longitudinal sectional view of a
hand tool embodying the present invention with its
valve in the open position;
FIG. 2b is an enlarged, sectional view of a
hand tool embodying the invention with its valve in the
closed position;
FIG. 2c is a sectional view taken along line
2c-2c of FIG. 2b;
FIG. 3 is a view of the underside of the hand
tool of FIG. 2b;
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FIG. 4 is a sectional view taken alony line
4-4 of FIG. 2a;
FIG. 5 is a schematic representation of an
auxiliary machine that may be used in conjunction with
the invention, appearing with Fig. l;
FIG. 6 is an enlargecl perspective view, part-
ly in exploded form, of a recirculating system used in
the preferred embodiment of the invention; and
FIG. 7 is a sectional vie~ taken along line
7-7 of FIG. 6.
DETAILED DESCRIPTION OF TH~ ERR~D rliBODIr~E~IT
The principles of this invention are particu-
larly useful when embodied in an u?holstery cleaning
apparatus such as that illustrated in the FIGS. 1 and
lS 2a-c, generally depicted by the nu~eral 10. The clean-
ing apparatus 10 includes a fabric cleaning tool 12
which is designed to apply a cleansing foam to the up-
holstery 11 and subsec~uently ~o remove tne foam ;~ith
the dirt released in the cleaning operation. n the
preferreci embodiment, the cleaninc; ~ool 12 is deslgned
to be hand operated, and is es?ecially sulted for
cleaning u?ho'stery. Neverthe}ess, it should be under-
stood that the present in-~ention is also suitable for
cleaning other fabrics, such as carpets, e-~en in its
?referred embodiment.
As shown in IGâ. 2a, 3 and 4, the cleaning
tool 12 comprises a generally hollow head 14 that is
at~acheà at its neck 23 to the cuff 22 of a vacuum hose
55. The external design of the head 1 is generally
constructed in accordance with ~he hand-tool cleaning
head disclosed iIl U. S . Patent No. 4,083,077 issued to
~night, et al., although the internal construction of
the head 1~ differs sigllificantly from that of the
E;night cleaning heacl. The external design of the head
~Z~S4~
disclosed in the Knight patent is particularly well
suited for cleaning upholstery.
Located within the head 14 are a first mixing
chamber 15 and a second mixing chamber 16 at the back
end of the head and a vacuum chamber 17 at the front
end of the head. The bottom of the head 14 is provided
with two vacuum intake slots 18 which lead into the
vacuum chamber 17, a foam output slot 19, and a
plurality of stationary brush bristles 20 which are
secured to the head 14 by screws 21.
As shown in FIG. 2a, foam 13 is generated in
the two mixing chambers and directed from the second
mixing chamber 16 through the foam output slot 19 to-
wards the upholstery 11 to be cleaned. The vacuum
chamber 17 is provided with sufficient suction to draw
the foam towards and through the vacuum intake slots
18. Due to the close proximity of the intake slots 18
- and the foam output slot 19 and to the suction in the
vacuum chamber 17, the foam is continuously and rapidly
moved from the output slot 19 to the intake slots 18.
The brush 20 serves to force the moving foam
over the top of the bristles and towards the fabric,
thereby creating a continuous wheel of foam between the
intake slots 18 and ou put slot 19. In the present
embodiment, the brush is made of soft nylon bristles.
It should be unders~ood that the brush may be made of
any suitable material, although it is preferred that
the bristles are sufficiently pliable so that the foam
also passes between the bristles when the apparatus is
applied to the fabric. Thus the foam is not forced
around the sides of the brush.
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In the preferred embodiment, the foam 13 is
generated by admixing pressurized air and a liquid
foam-producing cleaning solution. A solution input
conduit 24 and an air input conduit 25 enter the head
14 through the neck 23. Conduits 24 and 25 are con-
nected to inlet fixtures 26 and 27, respectively, and
these fixtures are threaded into orifices 31 and 32,
respectively, of a valve housing 30. The valve housing
30 is attached to a support 33 of the head 14 by screws
34. Within the valve housing 30, a valve 36 is forced
towards a valve seat 37 by a spring 38. The spring is
secured within a reservoir 44 of the valve housing 30
by a bolt 39 and washer 40.
The cleaning solution is delivered under
pressure via conduit 24 to the reservoir 44. When the
lever 42 is in its rest position, as shown in FIG. 2b,
the cleaning solution 75 is trapped within the reser-
voir 44. Air is delivered under pressure via conduit
25 to orifice 32 of the valve housing. A passage 46 is
provided within the valve housing 30 to allow the pres-
surized air to pass through the valve housing to a res-
ervoir 45. The diameter of the valve stem 47 of the
valve 36 is small enough to allow the air to travel
; through the reservoir 45 and into the first mixing
chamber 15 via a passage 51. The air is then forced
through the slots 49 and a first screen 50 into the
second mixing chamber 16 and out of the head 14 via the
output slot 19 and a second screen 52. Thus, there is
always a continuous flow of pressurized air through the
valve housing and mixing chambers. This continuous
flow of pressurized air is preferred because it mini-
mizes the erratic generation of foam and spurting.
The first mixing chamber 15 is defined by an
orifice 53 and the inner walls of a hollow cylinder 48,
which is threaded into the valve housing 30 and extends
g ~z~5~07
into the second mixing chamber 16. The cylinder 48 is
provided with a series of circumferential slots 49
which allow the foam yenerated in the first mixing
chamber 15 to be expressed into the second mixing cham-
ber 16. The first screen 50 is cylindrical in shape,and covers the slots 49 to regulate the consistency of
the foam. A neoprene gasket 54, through which the
cylinder g8 passes, is provided between the valve
housing 30 and second mixing chamber 16. This gasket
serves to prevent leakage bet~/een the second mixing
chamber 16 and the vacuum chamber 17 as such leakage
would diminish the suction in the vacuum chamber.
The second screen 52 covers the foam output
opening 19 at the bottom of the second mixing cham-
ber 16. This screen further controls the consistencyof the foam to provide uniform bubble size and density,
and assures even application of the foam to the uphol-
stery 11. In the preferred embodiment, the mesh of the
second screen 52 is finer than the mesh of the first
screen 50 in order to improve the consistency of the
foam generated.
~ 1hen the lever a2 is pulled towards the neck
23 of the head 14, as sho~m in FIG. 2a, it engages the
trigger pin 41 of the valve 35 to push the valve away
from the valve seat 37. The cleaning solution stored
in reservoir 4a is then forced down into reservoir 45
by the pressure of the incoming solution in conduit 24.
In the preferred embodiment, the free flo~ing pres-
surized air in passage 46 contacts the solution in res-
ervoir 45 perpendicularly in order to enhance admixtureof the two. The pressurized air forces the solution
into the first mixing chamber 15 where they thoroughly
admix to create a bubbled foam. This foam is then ex-
pressed through the slots 49 and first screen 50 into
the second mixing chamber 16 where it further admixes
- 10- ~2~54(~7
with the additional air always present in the second
mixing chamber. The force of the pressurized air input
to the reservoir 45, in addition to admixiny with the
solution to generate foam, also propels the foam through
the first mixing chamber 15, the second mixing chamber
16, and the second screen 52 towards the upholstery 11.
The pressure under which the air and cleaning
solu-tion are delivered to the reservoir 45 can be ad-
justed to control the consistency of the foam generat-
ed. By generating foam in the above described manner,a dry foam of uniform consistency can be achieved. The
dryness of the foarn can be controlled so that it is wet
enough to clean the fabric yet not saturate. This will
result in better recovery of the foam and ~uicker dry-
ing times. Moreover, by generating the foam in themixing chambers adjacent the fabric to be cleaned, the
consistency of the foam does not deteriorate during
transit.
Referring now to FIGS. 1 and 5, the fabric
cleaning tool 12 is connected by the vacuum hose 55 to
a cleaning machine 8. The cleaning machine 8 includes
. a dispensing tank 61 and a recovery tank 58. The dis-
pensiny tank holds a cleaning solution 75 and includes
a lid 7. A thermostatically controlled heater 63 heats
the cleaning solution 75. The temperature of the
cleaning solution is raised to improve its cleaning
efficiency. The heated cleaning solution is pumped
from the dispensing tank 61 via a pump 64. The pump
forces the solution through a delivery line 65, under
pressure, to the orifice 31. The solution is recycled
via a return line 66.
A vacuum 68 provides sufficient suction in
the vacuum hose 55 to rapidly and continuously recover
the foam generated at the foam output slot 19 travel-
ling across the upholstery 11 and into the vacuum in-
- 1 0
i4~7
take slots 18 so that the acceleration of the foam
across the fabric surface erodes and suspends embedded
soil into the foam. The suction created by the vacuum
68 further serves to transport the soiled foam through
the hollow cavity of the head 14 and the vacuum hose 55
to the recovery tank 58. The recovery tank 58 includes
a lid 59 and an inlet sleeve 60.
The cleaning machine 8 is also equipped with
a compressor 69 which provides pressurized air to the
orifice 32. The compressor 69 and pump 64, as well as
the size of the orifices 31 and 32, can be adjusted to
control the pressure under which the air and solution
are delivered to the orifices 31 and 32, thereby control-
ling the consistency of the foam generated.
The cleaning machine 8 also includes a reser-
voir 71 containing a defoaming agent which is mixed
with the soil-laden foam in the vacuum hose 55 and con-
verts it to a liquid. The soiled liquid 76 is then
removed from the vacuum hose 55 and stored in the
recovery ~ank 58. The foam destroyer reservoir 71 is
provided with a foam destroyer valve 73 which meters
the amount of defoaming agent that is mixed with the
soiled foam so as to afford liquifaction.
The heated cleaning solution, pressurized
air, and defoaming agent are conveyed from the cleaning
machine 8 via the delivery lines 65, 25, and 72, re-
spectively. The solution return line 66 recycles the
cleaning solution 75 to the dispensing tank 61. These
lines are connected to the cleaning machine 8 by use of
conventional quick-connect fasteners 80 a-d. The de-
livery and return lines run outside the vacuum hose 55
between the fasteners 80 a-d and the solution inlet
fixture 83, the solution outlet fixture 81, the air
inlet fixture 84, and the defoamer inlet fixture 82,
respectively. These inlet and outlet fixtures are
-12~ ~2~54~7
shown in FIGS. 6 and 7 circumferentially spaced and
radi~lly extending from the stationary sleeve 78. The
solution delivery and return lines 65 and 66 run longi-
tudinally within the vacuum hose 55 between the fix-
tures 83 and 81 and the block m~mber B8. The blockmember 88 is also connected to the solution input con-
duit 24 which leads to the valve housing 30.
The solution delivery and return lines 65 and
66, the solution inlet and outlet fixtures 83 and 81,
and the block member 88, together with the pump 64,
cooperate to provide a fluid recirculating system as
described in U.S. Patent No. 4,159,554 issued to
Knight, et al. In the present-system, a portion of the
heated cleaning solution 75 is recirculated by the so-
lution delivery and return lines 65 and 66 within thevacuum hose 55, with another portion passing directly
to the solution input conduit 24 for foam generation as
needed. With this type of arra~gement, the temperature
drop of the cleaning solution delivered to the block
member 88 from the temperature of the fluid in the dis-
pensing tank 61 is greatly reduced.
Referring now to FIGS. 2a, 6, and 7, it is
seen that the air input conduit 25 also runs longi-
tudinally within the vacuum hose 55 between the air
inlet fi~ture 84 and the orifice 32. The defoamer de-
. livery line 72 termina-tes at the defoamer inlet fixture
82, thereby introducing the defoaming agent into the
vacuum hose at this point. It is preerable to perform
the defoaming process in the vacuum hose 55 well before
; 30 the recovery tank 58 to maintain maximum vacuum.
-13-' ~2~54~7
The operation of the fabric cleaning tool 12
and the cleaning machine 8 will now be described.
First, the heater 63, compressor 69, pump 64, and vacu-
um 68 must all be energized. This may be done by a
conventional electrical connection, and a series of
switches may be provided for this purpose so that they
all may be energized collectively or independently.
Prior to energization, however, the operator should
make sure that a sufficient amount of cleaning solution
75 is retained in the dispensing tank 61, and that de-
foaming agent is retained in the foam destroyer reser-
voir 71. At this time, the recovery tank 58 should he
empty.
Once the above conditions have been moni-
tored, and power has been supplied to all the elements,the pump 64 will begin recirculating the heated clean-
ing solution 75 through the solution delivery and re-
turn lines 65 and 66. A portion of this cleaning agent
will pass into the solution input conduit 24 via the
block member 88. The cleaning solution in conduit 24
will then proceed to fill reservoir 44 of the valve
housing 30, as shown in FIG. 2b~ At the same time, the
vacuum 68 will create a suction in the vacuum hose 55
and vacuum chamber 17, and the compressor 69 will force
air to orifice 32 of the valve housing 30. The pres-
surized air will be forced through passa~e 46, reser-
voir 45, passage 51, the first mixing chamber 15, the
slots 49, the first screen 50, the second mixing cham-
ber 16, and finally through the bottom opening 19 of
the head 14 via the second screen 52.
To initiate the generation of foam, the operator
depresses lever 42, which controls the delivery of the
cleaning solution to the first mixing chamber. As shown
in FIG. 2a, this causes the valve 36 to open and allow
the cleaning solution 75 in reservoir 44 to flow into
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-14- ~2~S~7
reservoir 45. The forced air flowing from passage 46
contacts the cleaning solution in reservoir 45 perpen-
dicularly and forces it through passage 51 into the
first mixing chamber 15. The pressurized air and clean-
ing solution admiY~ with the additional air present inthe first mixing chamber 15 to generate foam bubbles.
The force of the incoming pressurized air expresses
this foam through the slots 49 and the first screen 50
into the second mixing chamber 16. The first screen
controls the consistency of the foam. The foam is further
admixed with the air that is always present in the sec-
ond mixing chamber 16 and expands to fill the entire
chamber, as shown in FIG. 4. The constant force of the
free-flowing pressurized air expels the foam 13 from
the second mixing chamber 16 through the second screen
52 and the foam output opening 19 towards the
upholstery 11.
The suction created in the vacuum chamber 17
accepts the foam 13 expelled from the output slot 19
via the vacuum intake slots 18 so that the foam moves
rapidly and continuously between the output slot l9 and
intake slots 18. The brush 20 forces most of the mov-
ing foam 13 over the tips of the brush, although the
bristles also allow some of the foam to pass between
them. Thus, a continuous, rapidly moving wheel of foam
is generated between the output slot 19 and the intake
slots 18.
~ hen ~he bottom of the cleaning head 14 is
applied to the surface of the upholstery 11, a compres-
sion is created between the back side of the brush 20and the output slot 19 which causes the bubble size of
the foam 13 to decrease, as shown in FIG. 2a. This
partial pressure is caused by resistance to the flow of
the moving foam, wnich is caused by the introduction of
the foam to the fabric surface and by the resistance
-14-
-15-' ~2~S4~7
provided by the brush 20 when it is compressed against
the fabric. The vacuum provided from the vacuum chamber 17
creates a decompression between the front side of the
brush 20 and the intake slots 18. Thus, a compression
and a decompression are created on opposite sides of
the brush. The brush 20, however, in addition to pro-
viding resistance to the flowing foam, is also suf-
ficiently permeable so that the foam moving under partial
pressure may pass through the brush to the decompression
created by the vacuum. Thus, the brush affords a pressure
variance across the brush, from the partial pressure at
its back side to the decompression at its front side,
to contain the flow of the moving foam through the brush.
In contrast, if no brush were provided between the foam
output slot 19 and the vacuum intake slots 18, the foam
would pass directly rom the compression, created by
the introduction of the moving foam against the fabric
surface, to the decompression, created by the vacuum.
Or if an impermeable barrier were provided between the
output slot l9 and intake slots 18, all the foam moving
under partial pressure would be forced around the edges
of the barrier. It should be understood that the brush
20 is the preferred way of creating a partial pressure
and a pressure variance across the brush, that other
means may be used similarly to create a partial pressure
and pressure variance.
The smaller foam bubbles resulting from the
partial pressure allow the bubbles to accelerate more
quickly along the surface of the fabric in a horizontal
direction, thereby increasing the agitating effect of
the foam without deep vertical penetration. When the
bubbles reach the other side of the brush, they encoun-
ter the decompression which causes their size to ex-
pand. Nevertheless, the suction in the vacuum chamber
17 removes these foam bubbles from the fabric via the
-16- ~2~S4Q7
intake slots 18. The suction continues to draw the
soil-laden foam through the hollow cavity of the clean-
ing head 14 and the vacuum hose 55. The defoaming
agent converts the foam to a liquid in the vacuum hose
at the defoamer inlet fixture 82. The soiled liquid 76
is removed from the hose 55 by the suction and is de-
livered to the recovery tank 58.
In the present invention, the continuously
ra~idly moving foam, under partial pressure, in immedi-
ate contact with the surface of the fabric, erodes andsuspends embedded soil instantly. Moreover, since the
foam is rapidly moving in the horizontal plane of the
fabric, it does not penetrate deeply into the pile of
fabric. Thus, it is easily removed by the suction of
the vacuum chamber 17 and does not overwet the fabric.
The brush 20 cooperates with the rapidly moving foam to
further agitate the fabric and foam to release and sus-
pend dirt into the moving foam, yet does not have the
harsh effect on fabrics of a rotating brush. To pro-
vide further, moderate agitation, it is preferable thatthe operator move the cleaning tool 12 in short, vigor-
ous strokes over the surface of the fabric to be
cleaned. It is also preferable that after the fabric
has been foam cleaned, as previously discussed, the
cleaning tool 12 be operated with only the vacuum to
remove any excess moisture that is removable.
Of course, it should be understood that vari-
ous changes and modifications of the preferred embodi-
ment described herein will be apparent to those skilled
in the art. Such changes and modifications can be made
without departing from the spirit and scope of the pre-
sent invention and without diminishing its attended
advantages. It is, therefore, intended that such
changes and modifications be covered in the following
claims.
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