U.S. patent number 3,831,223 [Application Number 05/222,000] was granted by the patent office on 1974-08-27 for carpet and upholstery cleaning apparatus with improved noise muffling feature.
This patent grant is currently assigned to Carpetech Corp.. Invention is credited to James G. Colt, Ronald W. Emus, Jr..
United States Patent |
3,831,223 |
Colt , et al. |
August 27, 1974 |
CARPET AND UPHOLSTERY CLEANING APPARATUS WITH IMPROVED NOISE
MUFFLING FEATURE
Abstract
There is disclosed apparatus for cleaning carpets, upholstery
and the like utilizing a meter driven separate reservoir system for
supplying a cleaning solution to a remote cleaning head adapted to
apply the cleaning solution to the material being cleaned, and a
separate motor driven vacuum pick-up system for storing cleaning
solution and entrained dirt picked up via the cleaning head. The
reservoir system may typically include in combination with a
reservoir tank a cleaning fluid pumping circuit comprising fluid
heating means, a fluid pump for supplying fluid from the reservoir
tank to the heating means, pressure regulator valve means for
returning heated cleaning fluid to the reservoir tank when the
fluid circuit to the cleaning head is closed, and flow sensitive
means disposed between the reservoir tank and the fluid pump
effective to disconnect the pump drive motor and shut down the
fluid pump and heater when the supply of cleaning fluid in the
reservoir tank is exhausted. The vacuum system includes a vacuum
tank supported by a base housing, and in the base housing a motor
driven vacuum pump for maintaining a partial vacuum in the vacuum
tank, muffler means coupled to the vacuum pump and exhausting into
a plenum chamber vented to the interior of the base housing, and
high density material disposed on at least the inner side walls of
the housing, together with a plurality of exhaust vents in the side
walls of the housing.
Inventors: |
Colt; James G. (Belmont,
MA), Emus, Jr.; Ronald W. (Billerica, MA) |
Assignee: |
Carpetech Corp. (Natick,
MA)
|
Family
ID: |
22830315 |
Appl.
No.: |
05/222,000 |
Filed: |
January 31, 1972 |
Current U.S.
Class: |
15/321;
15/326 |
Current CPC
Class: |
A47L
11/34 (20130101); A47L 11/4016 (20130101) |
Current International
Class: |
A47L
11/00 (20060101); A47L 11/34 (20060101); A47l
007/00 () |
Field of
Search: |
;15/320-321,326 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hornsby; Harvey C.
Assistant Examiner: Moore; C. K.
Attorney, Agent or Firm: Frederick; Melvin E.
Claims
Having thus described the invention, what is claimed as new and
desired to protect as Letters Patent is:
1. In two-tank cleaning apparatus for cleaning carpets and the like
in situ comprising a cleaning solution reservoir tank system and a
remote cleaning head, said reservoir tank system comprising a
reservoir tank and pumping means for supplying cleaning solution
under pressure to said cleaning head for ejection onto the surface
being cleaned; a vacuum tank pick-up system adapted for connection
to said cleaning head for recovering and collecting cleaning
solution ejected from said cleaning head comprising:
a. a hollow base housing having a bottom wall and side walls, said
side walls having a plurality of air vents spaced one from
another;
b. a vacuum tank having a bottom wall, said vacuum tank being
removably carried by and covering the top of said base housing;
c. first muffler means coupled to the interior of said vacuum
tank;
d. a plenum chamber carried in said base housing, said plenum
chamber having a plurality of openings to permit air to freely
escape into said base housing;
e. second muffler means carried in said base housing and coupled to
the interior of said plenum chamber;
f. air suction-blower means having an inlet and an outlet carried
in said base housing, said inlet being coupled to said first
muffler means and said outlet being coupled to said second muffler
means for evacuating air from said vacuum tank and exhausting it to
the interior of said base housing; and
g. sound deadening material bonded to the bottom wall of said
vacuum tank and the side walls of said base housing.
2. The combination as defined in claim 1 wherein said first muffler
means is of the straight-through type having an open axial passage
through which air from said vacuum tank passes and is disposed in
said base housing.
3. The combination as defined in claim 2 wherein said first muffler
means is effective to absorb high frequencies generated by
operation of said suction-blower means and is disposed in said
vacuum tank.
4. The combination as defined in claim 2 wherein said first muffler
means comprises a tubular screen defining an open axial passage
through which air from said vacuum tank passes, and fibrous sound
absorbent material surrounding said tubular screen.
5. The combination as defined in claim 4 wherein said second
muffler means is of the straight-through type having an open axial
passage through which air from said vacuum tank passes and having
sound absorbing means surrounding and in communication with the
interior of said axial passage.
6. The combination as defined in claim 1 wherein said first and
second muffler means are of the straight-through type having an
open axial passage through which air from said vacuum tank passes
and having sound absorbing means surrounding and in communication
with the interior of said axial passage.
7. The combination as defined in claim 1 wherein said sound
deadening material includes a high density material effective to
absorb low frequencies generated by operation of said
suction-blower means
8. The combination as defined in claim 7 wherein the mass per
square inch of said sound deadening material bonded to the bottom
wall of said vacuum tank is greater than the mass per square inch
of said material bonded to the side walls of said base housing.
9. The combination as defined in claim 1 wherein said sound
deadening material comprises lead sandwiched between two layers of
polyurethane foam.
Description
The present invention relates to carpet and upholstery cleaning
apparatus, and more particularly to such apparatus for supplying a
cleaning fluid under pressure to a cleaning head for application to
a carpet and providing vacuum pick-up means to withdraw from the
carpet the cleaning fluid and entrained dirt.
In the cleaning of carpet and upholstery, it has been found
effective to discharge a jet of pressurized cleaning solution into
the pile, nap, or weave of the fabric to be cleaned, and to
thereafter apply suction to the fabric to withdraw the used
cleaning solution from the fabric together with the dirt loosened
and entrained in the cleaning solution.
Cleaning apparatus of the type referred to above may comprise, for
example, a liquid tank and vacuum tank each mounted on separate
base structures housing a drive motor and its associated
components. A motor drives a suction blower, the intake side of
which is coupled to the interior of the vacuum tank while the
discharge side of the vacuum blower discharges to the atmosphere
either directly or through a muffler. A liquid pump also driven by
a motor is connected to draw liquid from the liquid tank and feed
the liquid under pressure to heating means which is then discharged
through a hose and control valve to a spray or cleaning head
adapted to discharge the heated liquid onto the material being
cleaned. For a more thorough discussion, reference is made to
patent application Ser. No. 25,521, filed Apr. 3, 1970, now U.S.
Pat. No. 3,663,984, issued May 23, 1972 and assigned to the same
assignee as this application.
Other cleaning devices particularly devoted to commercial cleaning
fields have been provided which include fluid distribution means
and a vacuum means for picking up fluid and loosened material from
surfaces after the surface has been scrubbed by brushes or the
like. Still other devices have been provided which include means
for high pressure fluid distribution and vacuum pick-up means for
receiving the fluid delivered to the surface to be cleaned. The
picked-up fluid may or may not be returned for recirculation. These
devices operate on the principle that the high pressure fluid
delivery serves as the cleaning and scrubbing element thereby
eliminating the use of brushes or other scrubbing devices.
Whether one is concerned with two-tank cleaning apparatus as
described above or any other apparatus having similar power
requirements, in every case the power consuming characteristic of
the apparatus has in the past been effectively limited to
relatively low levels. This power limitation is due to the fact
that the National Electric Code requires that all residential and
industrial conventional convenience outlets be wired and fused for
only fifteen amperes.
In the past this limitation in available electrical power from any
convenience outlet has severely limited the design, capability, and
efficiency of such devices because their electrical power
consumption must be limited to relatively low values, even if
separate electrical devices are provided for connection to separate
outlets as taught in the aforementioned Pat. application Ser. No.
25,521. For a description of a method of and apparatus for
combining electrical power from two separately fused circuits and
supplying same to carpet cleaning apparatus of the type here
concerned, wherein current in excess of that avilable from one
convenience outlet may be supplied to the vacuum drive motor for
example, while still supplying sufficient current to the other
power consuming devices, reference is made to Pat. application Ser.
No. 154,889, filed June 21, 1971, now U.S. Pat. No. 3,697,771 and
assigned to the same assignee as this patent application.
A further undesirable feature of prior art cleaning devices is,
notwithstanding the use of mufflers, the high noise level
inherently associated with their use. For this reason, most if not
all known cleaning devices are not satisfactory for use in
hospitals and the like where loud or high level noises are not only
objectionable, but generally not permitted. However, cleaning
systems in accordance with the present invention are not subject to
such objections and have been approved for use in and used in
hospitals.
It is an object of the invention to provide improved cleaning
apparatus having a vacuum pick-up system.
Another object of the invention is to provide improved cleaning
apparatus designed to deliver a heated cleaning solution under
pressure to a surface to be cleaned and to recover the solution
through the use of a vacuum system.
A further object of the invention is the provision of improved
cleaning apparatus wherein cleaning fluid is recovered by a vacuum
pick-up system with minimum noise associated with its use.
A still further object of the invention is the provision of
improved cleaning apparatus wherein cleaning fluid is recovered by
a vacuum pick-up system which is quiet in operation.
The novel features that are considered characteristic of the
invention are set forth in the appended claims; the invention
itself, however, both as to its organization and method of
operation, together with additional objects and advantages thereof,
will best be understood from the following description of a
specific embodiment, when read in conjunction with the accompanying
drawings, in which:
FIG. 1 is a diagrammatic view of a reservoir system;
FIG. 2 is a diagrammatic view of the vacuum pick-up system in
accordance with the invention;
FIG. 3 is a diagrammatic and fragmentary side view, partly in
section, showing details of the vacuum pick-up system in accordance
with the invention.
FIG. 4 is a perspective view of a remote cleaning head for cleaning
carpets together with a reservoir and vacuum pick-up system.
Directing attention now to the drawings, in FIG. 1 is shown the
reservoir system designated generally by the numeral 10. The
reservoir system may be supported by an acoustically insulated base
housing as shown for example in FIGS. 3 and 4, the reservoir or
solution tank 12 being removably attached as by hooks or the like
to the upper surface of the housing and the balance of the
reservoir system more fully described hereinafter being contained
in conventional manner within the base housing.
At the base of the reservoir tank may be provided two connections
preferably of the conventional "quick disconnect" type so that the
reservoir tank can be simply, quickly, and without loss of fluid,
removed from the base housing while still containing a liquid or
cleaning solution. Disposed within and supported by the base
housing is an electric drive motor 15 coupled, for example, in
conventional driving relationship via pulleys to a solution or
liquid pump 16. While the electric drive motor must meet certain
power requirements, the liquid pump employed may, in accordance
with the invention, be of a simple and inexpensive type without any
protective means or apparatus to protect the pump against damage in
the event the pump inlet iw not continuously supplied with fluid.
Since several well-known types are suitable for the purpose, the
details thereof are not illustrated or described herein.
The inlet or low-pressure side of the liquid pump 16 may be
connected by a conventional pipe or liquid supply line 19, a
pressure or flow sensitive switch 25 more fully disclosed
hereinafter, and a flexible hose 26 to the quick disconnect
connection 13 as shown.
As will become more evident hereinafter the inlet and outlet sides
of the liquid pump need not be coupled through conventional by-pass
means including pipes and a pressure regulator for maintaining a
predetermined pressure at the outlet of the liquid pump as shown.
The liquid pump may be of a conventional type as noted above and
typically should at least be capable of providing an outlet
pressure of about 100 psi at flow rates of about 2 gallons per
minute. The outlet of the liquid pump 16 communicates through pipe
31 and a one-way check valve 32 with the lower end of a
conventional electric type heater means 33 for at least maintaining
the temperature of cleaning fluid at a suitable temperature to
provide at the outlet of the heater, a temperature of, for example,
about 160.degree. F. The cleaning fluid is most conveniently
initially provided in the tank 12 by mixing suitably hot water with
concentrated detergents and the like. A suitable heater may be, for
example, a "Chromalox", Model No. B, manufactured by the Edwin L.
Wiegand Company which includes adjustable thermostat means 33a to
control the temperature to which the liquid is heated by the
heater.
The outlet side of the heater 33 communicates through one port of a
T-connection via pipe 34, flexible hose 30, a pressure regulator
35, and connection 14 with the interior of the reservoir tank 12.
Through the other port of the T-connection, the outlet of the
heater also communicates via pipe 36, filter 37, adjustable flow
pressure valve 38, pressure gauge 39 and a quick disconnect
connection 41 with an insulated and flexible high temperature fluid
hose 42, the remote end of which hose communicates with a suitable
cleaning head shown in FIG. 4 and more fully described hereinafter
and in said application Ser. No. 25,521. Heated fluid may flow from
the heater 33 in one of two directions, the first of which is
through pressure regulator 35 and back into the reservoir tank and
the second of which is via pipe 36, adjustable flow pressure valve
38 and flexible hose 42 to the cleaning head. Pressure regulator 35
is adjusted to open and permit heated fluid to pass therethrough
when the pressure in line 34 is greater than a predetermined amount
such as, for example, 75 psi. Adjustable flow pressure valve 38 is
a normally closed, solenoid actuated type flow valve having an
on-off switch 46 connected in series therewith and a pilot light
47. Both the switch 46 and pilot light 47 are preferably mounted on
the base housing. The pilot light 47 is of course lit when switch
46 is closed thereby indicating that valve 38 is in its actuated
position.
When the control valve in the cleaning head is in its normally
closed position, thereby preventing the discharge of cleaning fluid
(or flexible hose 42 is disconnected thereby closing line 36 at
connection 41), cleaning fluid in the reservoir tank will be
continuously supplied to the heater 33, heated, and then circulated
back into the reservoir tank 12. The adjustable flow pressure valve
38, pressure gauge 39, and one-half of connection 41 may be mounted
in the base housing. The quick disconnect connection 41 is, of
course, poled such that the high temperature fluid line 36 is
closed when the flexible hose 42 to the cleaning head is
disconnected.
When the high temperature fluid line 36 is coupled to the cleaning
head via hose 42 and the control valve at the cleaning head is
opened, the heated fluid which previously was flowing back into the
reservoir tank via pressure regulator 35 now flows through the high
temperature flexible hose 42 and is discharged at the cleaning head
because the pressure on the heater outlet side of pressure
regulator 35 drops below the critical pressure at which it is set
and, accordingly, pressure regulator 35 closes. Upon closure of
regulator 35, the heated fluid is directed to the cleaning head.
When the control valve on the remote cleaning head is closed or
hose 42 is disconnected, the pressure on the heater side of
pressure regulator 35 increases thereby causing pressure regulator
35 to exceed its critical pressure and, hence, open and permit
heated cleaning fluid to gain be circulated back to the reservoir
tank. As will now be obvious, there is a continuous flow of fluid
from the reservoir tank to the heater and thence back to the
reservoir tank except when fluid is permitted to be discharged at
the cleaning head. This permits the solution in the tank to be at
least continuously maintained at an initial predetermined
temperature thereby allowing maximum cleaning capability to be
effected by the cleaning solution.
The foregoing arrangement also results in continuous pressurized
flow of fluid through the pump 16 irrespective of whether cleaning
fluid is being used or not. Accordingly, during any time that motor
15 is actuated no damage can result to the motor driven pump or the
system so long as sufficient cleaning fluid is contained in tank 12
to permit continuous circulation via pipes 26 and 30.
Directing attention now to FIG. 2 there is shown the vacuum tank
pick-up system generally designated by the number 55 comprising a
vacuum tank 56 that may be removably supported as by hooks on a
second base housing (see FIGS. 3 and 4), a second drive motor 58,
and a suction blower 59. The drive motor 58 may be drivingly
connected as by a pulley-belt system to the suction blower 59. The
suction blower may be of the positive displacement type. While a
positive displacement type blower is preferred, the specific type
of suction blower employed is not material to the invention, and
since several well-known types are suitable for the purpose, the
details thereof are not illustrated or described herein.
A muffler 57, preferably of the type adapted to most effectively
absorb the high frequencies generated by the vacuum pick-up system,
is coupled between the outlet of tube 63 and the inlet or low
pressure side of the suction blower 59 by hoses 60 and 61. The
upper end of the flexible hose 60 is removably fitted onto the
lower end of a suction tube 63 incorporated axially in the vacuum
tank 56. The flexible hose 60 preferably is of the annularly
corrugated, axially resiliently extensible type to permit it to be
easily connected and disconnected from the axial tube 63 of the
vacuum tank 56. Where space in the base housing permits, the
muffler 57 may be located therein, as shown, for example, in FIG.
3. However, if desired, or if space is not conveniently available
in the base housing, muffler 57 may be disposed in or made integral
with tube 63 as shown in phantom in FIG. 2. This latter location of
muffler 57 in vacuum tank 56 has the added advantage of providing
further reduction of noise because of the attenuation or absorption
of noise emanating from muffler 57 by tank 56 and its contents.
The outlet or high pressure side of the suction blower 59
communicates with a plenum chamber 77 through pipes 62a and 62b,
straight-through type mufflers 74 and 75, and pipes 76a and 76b. In
accordance with the invention all of the above components are
suitably supported and disposed within the vacuum system base
housing. One wall of the plenum chamber 77, preferably one remote
from the point where hoses 76a and 76b are connected to the plenum
chamber and one freely communicating with the interior of the base
housing, is provided with a plurality of apertures 78 to permit the
air received from the vacuum tank to freely escape to the interior
of the vacuum system base housing. The total cross sectional area
of the apertures 78 must be greater than the total cross sectional
area of the hose or hoses connecting the plenum chamber and the
mufflers.
Since the air introduced into the plenum chamber from the vacuum
tank carries a large amount of moisture, a drain valve disposed at
the bottom of the plenum chamber is necessary since the plenum
chamber will eventually fill up with water if it is not
periodically emptied. Further, if the water level in the plenum
chamber is permitted to or is capable of covering the outlets of
the hoses coupling the plenum chamber to the muffler or mufflers,
this will cause the back pressure on the suction blower to increase
significantly and greatly reduce the efficiency of the system if
not result in failure or overheating of the suction blower and its
drive motor.
Because of the moisture involved, the mufflers are conveniently
made of stainless steel, while the plenum chamber may be of
stainless, or preferably to reduce weight, irridited aluminum. The
mufflers 57, 74, and 75 are all of the straight-through type to
keep pressures within the system at a minimum, especially the back
pressure on the suction blower as this in turn keeps the lead on
drive motor 58 at a minimum. However, it is important that muffler
57 be arranged and adapted, as by providing a tubular screen 79
(see FIG. 3) for the straight-through portion, to more effectively
permit absorption of the high frequencies generated by the system
since it has been found that the high frequencies are associated
with the inlet region of the suction blower.
The use of the tubular screen 79 (rather than a conventional solid
metal pipe with a plurality of holes) has been found to be most
effective as this construction more effectively reduces the level
of the high frequencies generated by operation of the vacuum
pick-up system.
On the other hand, mufflers 74 and 75 may be of conventional
straight-through design. Further, while a plurality of mufflers are
shown as being coupled to the outlet of the suction blower, more or
less than two may be used as space and muffler design permit.
Directing attention now particularly to FIG. 3, to maintain at a
minimum the low frequencies generated by operation of the system,
the side walls 80 of the vacuum system base housing and the base 81
of the vacuum tank 56 are covered with a high density sound
deadening material 82, such as for example sheet lead sandwiched
between two layers of polyurethane foam or the like. Such a
suitable material is manufactured and sold in one-half and
three-fourths inch thicknesses by Soundcoat Company, Inc., of New
York, N. Y. The high density material 82 in thicknesses of up to
one inch may conveniently be bonded to the side walls 80 of the
base housing and the bottom 81 of the vacuum tank 56. Maximum noise
reduction is obtained if the thickness of the material on the
bottom of the vacuum tank is thicker than that on the side walls of
the base housing as shown. Thus, if one-half inch thick material is
provided on the side walls, three-fourths inch thick material
should be used on the bottom of the vacuum tank.
We have found that the bottom member of the base housing to which
is attached the suction-blower, drive motor and the like, need not
be provided with the material 82 because the bottom member
inherently has a high mass, due principally to the components it
supports. Any noise transmitted through this bottom member is
substantially absorbed by the carpet being cleaned and on which it
is normally disposed during use.
Due to its high mass, the bottom member is effective in absorbing
low frequency noise generated in the base housing. Because the side
walls inherently have a low mass, addition of material 82 has been
found necessary to obtain effective absorption of noise generated
in the base housing.
To further effect muffling of noise, the air is not only exhausted
into the interior of the base housing, but is vented to the
exterior thereof by a plurality of spaced vents or louvers 83
suitably disposed around the periphery of the base housing. The
provision of numerous spaced vents 83 permits the air pumped from
the vacuum tank into the interior of the base housing to be vented
with the generation of little if any noise while effectively
trapping within the base housing that noise generated or emitted
therein.
A suitable base housing may be of stainless steel sheet metal,
cylindrical, mounted on casters, and of a size to receive the
components as described hereinbefore.
The vacuum tank is of the same size and generally of the same
structure as the reservoir tank. Each may comprise a conventional
domed bottom, sealed into the lower end of a conical wall having a
radially inwardly extending shoulder. While the upper end of the
reservoir tank is open, that of the vacuum tank is closed, and has
a suction relief valve 64 mounted thereon. The suction relief valve
64 is so adjusted that when the pressure within the vacuum tank
drops below a pre-set minimum of the relief valve, the latter will
open to permit atmospheric air to bleed in and thus limit the
vacuum in the tank to the desired level. A conventional vacuum
gauge 65 is mounted on the vacuum tank to indicate the degree of
vacuum therein. Also mounted on the vacuum tank is a soiled water
level control switch 66. Switch 66 is connected in series via
conductor 67 with the drive motor 58 to shut the motor off when the
liquid level in the vacuum tank approaches the top thereof. Also
provided adjacent the top of the vacuum tank is a suction inlet 68
for communicating the vacuum hose 69 with the interior of the
vacuum tank. The remote end of the vacuum hose 69 is coupled to the
cleaning head as and for the purposes more fully described
hereinafter. A drain valve 71 is also provided at a low point in
the vacuum tank for draining soiled cleaning solution therefrom. An
extension cord 72 is provided for connection to a suitable source
of electric power for operating the motor 58. Similarly, an
extension cord 73 may be provided for connecting drive motor 15 of
the reservoir system to a suitable but separately fused source of
electric current. Pressure switch 25 is connected in series with
electric motor 15 via conductors 74. Flow sensitive switch 25 may
be any conventional type such as, for example, a McDonnell No. FS1
flow switch manufactured by McDonnell and Miller, Inc., of Chicago,
Ill., which is comprised of an electrical switch portion controlled
by a flow sensitive portion through which the monitored fluid
flows. The point of actuation of the switch is variable whereby the
switch can be set to be actuated from a minimum to a maximum flow
velocity.
As shown in FIG. 1, the electrical switch portion of switch 25 is
connected in series with the input line. Thus, when normal flow in
house 26 is interrupted, as when tank 12 is empty or flow via hose
30 or line 36 is blocked, this condition is detected by switch 25
and the flow of current to motor 15, heater 33, and flow control
valve 38 is interrupted. In short, the reservoir system is shut
down, thereby preventing damage to heater 33 and/or damage to pump
16 that may otherwise result from their continued use without a
continuous supply of fluid. It is to be understood that while
switch 25 is shown as being located intermediate hoses 26 and 19 in
the input line to pump 16, it can operatively be located in line 31
or line 34.
Referring now to FIG. 4, a suitable cleaning head is indicated
generally by the numeral 181 and includes a floor tool head
assembly 182 and a handle assembly 183. The floor tool head
assembly includes a pick-up nozzle unit 184 to which is secured a
roller 187. When the roller 187 is in contact with the surface of
the carpet or the like being cleaned, the nozzle unit 184 is in
contact with the surface being cleaned.
The nozzle unit 184 is generally hollow having converging front and
rear walls and side walls defining a suction chamber having an
elongated narrow suction opening. In the working position shown in
FIG. 4, the nozzle opening of the nozzle unit is maintained in
contact with an upper surface of a carpet being cleaned. Cleaning
fluid dispensing means (not shown) may be disposed intermediate
nozzle unit 184 and roller 187. Such cleaning fluid dispensing
means may conventionally include a plurality of adjustable jet
outlet nozzles each providing a fan shaped spray and uniformly
spaced from one another on a common axis. The nozzles are
preferably canted slightly such that the edges of the fan shaped
spray from the nozzles overlap but do not interfere one with
another. This is effective in preventing what is commonly referred
to as streak lines in a carpet.
The operation of the illustrative form of the invention is as
follows:
With the reservoir tank and vacuum tank pick-up systems assembled
and the cleaning head operatively connected, the drive motors are
connected to a source of electric current. A supply of cleaning
solution such as, for example, heated water with suitable cleaning
and/or solvent material in solution therein, is poured into the
open top of the reservoir tank 12, the amount and type of solution
used being determined by the nature of the cleaning job to be
performed. With the drain valve 71 of the vacuum tank 56 closed,
and the suction relief valve 64 and the pressure regulator valve 35
set to the desired settings, the separate drive motors 15 and 58
and the heating element of the heating means 33 are energized. With
the reservoir system drive motor 15 and the heater 33 operating,
the liquid in the reservoir tank is almost continuously being
heated and the suction blower 59 immediately reduces the pressure
within the vacuum pick-up tank 56 which causes a partial vacuum in
the suction hose 69. The size of the suction nozzle is preferably
such as to limit the flow of atmospheric air therethrough to a rate
below the capacity of the suction blower 59, so that were it not
for the vacuum relief valve 64, the vacuum in the hose 69 would be
greater than desirable. Accordingly, a suitable setting of the
vacuum relief valve 64 is such as to maintain the vacuum in the
tank 56 at a suitable level below ambient atmospheric pressure.
With the system thus operating and after a few moments have been
allowed to permit the heating of the liquid in the heater 33, the
control valve at the cleaning head may be opened to permit the
discharge of cleaning fluid via appropriate nozzles onto the
surface to be cleaned. For a further discussion of an appropriate
cleaning head reference is made to said application Ser. No.
25,521.
The suction nozzle of the cleaning head is drawn in successive
strokes across the material to be cleaned while at the same time
operating the control valve as required to direct fan-shaped
streams of heated cleaning fluid from jet outlet nozzles in the
cleaning fluid dispensing means onto the material being cleaned.
The dirt from the material being cleaned together with the cleaning
solution used, and atmospheric air drawn through such material, are
all sucked into the cleaning fluid pick-up chamber of the nozzle,
pass thence through the vacuum hose 69 and are discharged in the
vacuum tank 56 through the suction inlet tube 68. The air then
passes through pipe 63 and is discharged inside of the vacuum
system base housing via the muffler system comprising mufflers 57,
74 and 75 and plenum chamber 77. After being exhausted into the
base housing the air then passes to the atmosphere through the
vents in the base housing.
The soiled cleaning fluid is discharged through the vacuum inlet
tube 68 into the vacuum tank 56 in conventional manner to prevent
the flow of said cleaning fluid through the suction blower. At
desired intervals, the collected cleaning fluid may be manually
drained from the vacuum tank 56 by opening the drain valve 71 or
pumped out as by an automatically controlled dump pump or the
like.
All during the time that the system is being used, cleaning fluid
is continuously being supplied to pump 16 and either returned to
tank 12 or supplied to the remote cleaning head. Thus the pump is
not exposed to any danger of failure resulting from a lack of input
fluid at any time so long as some fluid is present in tank 12. When
the fluid in tank 12 is exhausted, this condition is immediately
detected by switch 25 which is effective to immediately shut down
the reservoir system thereby preventing any possible damage to the
pump 16 or heater 33 in the event it is not protected by a thermal
cut-out switch. As will now be evident the above described
arrangement not only permits the use of inexpensive and/or
unprotected pumps, but also permits the elimination and consequent
cost of thermal protective means for the heater, thereby achieving
not only more efficient operation but a reduction in component and
assembly cost.
For rugs of small pile height and/or lightly soiled rugs, switch 46
which may be conveniently mounted on the base housing, is actuated
to its closed position, thereby providing actuation of valve 38 and
pilot light 47. When valve 38 which is arranged and adapted to
provide two rates of flow onto the surface being cleaned, (a low
flow of about 1 gallon per minute and a high flow of about 2
gallons per minute), is in its normally open or unactuated
position, cleaning fluid flows through it at the high flow
rate.
When switch 46 is closed, valve 38 is actuated and permits cleaning
fluid to flow therethrough at the low flow rate.
The provision of a low flow and a high flow rate is particularly
advantageous when the remote cleaning head is of the small hand
held type useful for cleaning carpets on stairs, in corners, and
furniture and the like.
While a preferred embodiment of the invention has been illustrated
and described, it will be understood, however, that various changes
and modifications may be made in the details thereof without
departing from the scope of the invention as set forth in the
appended claims.
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