Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUI~ B }NVENT ON
3y their very nature, wet/dry vacuum cleaner require
powerful high speed motors to drive the vacuum producing air
pump. Generally, large amounts of cooling air are required to
keep the temperature of the motor within suitable operating
temperature limits, and for the most part, little attention
has been placed on the movement of air through the motor cool-
ing ducts, with a view to cooling the motor in the presence
of water spillage at or ne æ the motor housing. Motors driving
the air pumps of this class of vacuum cleaner, that is wet/dry
vacuum cleaners, may be located in a variety of locations with
respect to the soil containment vessel. Some models place the
motor below the containment vessel, such that the motor is
particularly vulnerable to the ingress of water or other
cleaning liquids into the ventilation system of the motor~
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SUMMARY OF ~æ INVEN~ION
~ his invention seeks to provide ventilation for a
motor driving an air pump on a wet/dry vacuum cleaner which
is located above the soil containment Yessel. ~he motor and
air pump share a co~mon shaft and the same contai~nent
housing, although ~ interior wall is pro~ided in the housing
to separate the air pump from the motor, the common shaft
passing through this interior wall. ~he motor/fan housing is
of a bulbous shape and has a pair of ribbed members projecting
therefrom to subsequently define the ~entilation air flow
passages for cooling air. A cap, which too is of a bulbous
shape9 is subsequently fitted onto the motor/fan housing, such
that the ribbed members maintain a predetermined space between
the cap and housing.
The ribbed members serve to divide the space between
the cap and housing into two separate air passages 7 one for
cooling air entering the motor and the other for the discharge
of heated air to atmosphere. The intake air is drawn in
under the cap and mu~t pass upwardly a considerable distance
to the top of the motor housing before being ducted downwardly
into the housing into the interior of the motor, where it is
heated and subsequently passed through a ~et of exhaust ports
in the motor housing under the cap and downwardly in the
exhaust duct defined by the ribbed members to exit at the
bottom of the cap member to atmosphere.
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Figure 1 is a perspective view of the vacuum cleanlng
machine, showing the general nature of and relationships of the
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various parts ma~ing up the machine.
Figure 2 is an enlarged exploded partial perspective
view providing a general overall view of the vacuum cleaner.
Figure 3 is a partial view of the machine, showing
only the vacuum producing machinery, the motor and containment
vessel.
~ igure 4 is a sectional view of the machine shown in
~ig. ~.
Figure 5 is an enlarged illustration of the captive
floating "pancake" assembly o~ Figure 4.
DESORIP~ION 0~ TEE PRE~ERRED EMBODIMENT OF ~HE
INVE~IO~
Referring now to ~igure 1, an electric wet vacuum
cleaning machine 10 is illustrated. ~he machine essentially
comprises a wagon body 12 shown mounted on 4 caster wheels
for ease of tran~port. The wagon 12 comprises 2 part~9 a
lowcr base portion 12a and an upper mating part 12b (see ~igure
2). ~he wagon serves to carry the twin containers 14 and 16.
Container 14 is filled with a liquid cleaning solution,
which is expected to be a watex-detergent mixture. If desired,
the liquid cleaning solution may be heated externally of the
cleaning machine and placed in the container or the solution
may be used u~heated. Although this descriptio~ does not
include it, provi~ion may be made to provide heat for the
clca~ing solutio~ in ~itu in the wagon 12 by means of an
electrical heater or some ~ther suitable type o~ heater.
~ he clea~ing solution in container 14 is carried ~ay
from the container 14 by means of adapter 18 to which hose 20
is ~ecured~ Hose 20 i~ connected to pump 22 which is part o~
a~ i~tegral pump motor combination~ ~he outlet hose 24 is
connected to control valve 26 which is ultimately co~r.ected to
to Sprayer wand 28.
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~ ontainer 14 is shown in the illustrated embodiment
as being integral with upper part of wagon 12. It is expected
that the complete wagon assembly 12 will be preferably composed
o~ a high impact molded plastic material. Thi3 has the advan-
tage of being a good heat and electrical insulator~
Vacuum container 16 is also pre~erably fabricated from
a high impact molded plastic material. ~he container 16 is
covered by a composite sealing lid assembly 30 which sealedly
covers container 16 and houses the air pump and motor which
provides vacuum for the machine.
Examining the lid assembly in greater detail, as shown
in Figures 2 and 4, it will be seen that an electric motor 32
is mounted therein in top most housing 33. Mounted in the
same lid assembly and in the lower part o~ housing 33 and on
the same sha~t 34 is centrifugal ~an or air pump 36. Fan 36
is mounted to rotate in housing 38.
~id 30 is provided with an interior flanged wall 40
which provides a mounting surface for housîng 38 of the fan
assembly. Housing 38 is ~astened in any suitable manner to
wall 40 by screws or rivets etc., as long as housing 38 and
wall 40 are in a sealed relationship. ~his is necessary to
keep any foreign material from passing from chamber 44 to 42.
It ~ight also be mentioned here that the particular motor and
fan a~sembly illustrated in the drawings a~d preferred for
this application includes in its construction, a sealing member
between the fan or impeller compartment 38 and the motor
housing 32. Although the specific construction of the sealing -
~ember will not be described in this application, these seals
are well known and comprise generally ~ non metallic washer
assembly mounted on the dividing wall to mate with the rotating
shaft.
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~ he motor compartment 42 is capped by a special cap
46 of a bulbous shape which is arranged to fit over rib members
48 as best shown in Figure 3. It will immediately be seen in
~igure 4 that when cap 46 is in its permanent functioning
position, a space 50 is left between the lower lip of cap 46
and housing 33. Cap 46 may be fastened to housing 33 by
means of suitable adhesive or other fastening means such as
screws, rivets etc., as long as this cap is securely held in
place.
Gap 46 performs a most important function to direct
the cooling air for motor 32, whilst preventing the ingress
of water droplets to the motor itself, whilst permitting air
to enter the motor oompartment. Air is permitted to enter a
pair of opposing compartme~ts formed by housing 33, ribs 48
and cap 46, through opening 50. ~he cooling air must then
travel a sub~tantial distance up the compartment so formed to
pass through openings 52 in the top of motor housing 32. ~he
air thence passes through motor fan 54 and through the passages
provided in the motor housing to cool the motor itself. The
air 90 heated passes out through a series of holes (not shown)
in hou~lng 32 ancl passes into space 42 in housing 3~. ~rom
space 42, the heated air passes through apertures 56 into the
space provided between cap 46 and housing 33 between ribs 48.
It is noted that ribs 48 serve to isolate the two inlet com-
partments from the compartments carrying the heated exhaust air.
It will be noted that cap 46 serves to protect the
motor from the ingress of moisture by its size and location on
the housing 33c It is to be expected that in the environment
in which this machine will be used, that there is a substantial
risk th~t water will be spilled over the motor vacuum assembly
30. In thi~ event, cap 46 will serve to defleet ~ny water ~o
spilled down ~ver the sides o~ cap 46. Spaces 50 are designed
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to be large enough so -that in the areas of the intake air to
the motor, the velocity of the air rushing into the motor fan
compartment will not be sufficient to carry any of the water
droplets falling from the lower lip of cap 46 over spaces 50,
up into aperture 52 and into the motor itself.
It might be mentioned here that rib extensions 48a are
~ormed on the top of housing 33~ which are foxmed integrally
with ribs 48 so as to complete the isolation of the inlet and
exhaust compartments beneath cap 46. ~ecause of the seal
between the motor compartment and the fan compartment and the
method of sealing the housing 38 to wall 40, all the exhaust
air from the motor compartment must be discharged through
apertures 56 to atmosphere~ Similarly, none of the air in
chamber 44 is permitted to pass into space 42 because of the
aforementioned descriptionO
~ he air flow path through the vacuum pump assembly
will now be described. Referring to ~igure 1, a wand assembly
70 is illustrated comprising an appliance tool 72 mounted on
the hollow tubular wand 74. Wand 74 is connected to a flexible
hollow tube 76 which æubsequently is fitted to adapter 78,
which terminate~l in the space 80 provided in container 16 in
a right angled ~lbow 82. Air carrying soil and liquid deter-
gent/soil mixture i9 drawn through tool 72 into tube 74,
tubing 76 into member 78 and thence through elbow 82 into
spæce 80 in container 16. The location of member 78 in con-
tainer 16 is quite important. ~he elbow member 78 is located
near the top of container 16 for several reasons. Firstly,
; con~ainer 16 will no doubt be filled to capacity on occasion
~nd the liquid in the chamber 16 will tend to run out the
~0 member 78 if it iq located too far down the side of the
container 16 if the motor 32 driving the vacuum pump is shut
of~ when container 16 is full.
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Elbow member 78 also serves to deflect the air
stream exiting therefrom up onto the lower surface 84 of lid
assembly 30 in such a manner that the air is separated from
the liquid detergent/soil mixture, such that the liquid
mixture is not drawn into the vacuum pumpO Also, since the
air from the hose is expelled upwardly toward surface 84,
any tendency to cause turbulence at the liquid surface below
is avoided. Such turbulence at the water surface, can set
up critical wave action under certain circumstances, resulting
in ingestion of droplets of the liquid/soil mixture into the
air pump.
Member ~0 is provided with a substantially flat seal-
ing member 86 which extends substantially over the complete
lower opening of lid member 30. Member 86 is provided with a
seal 88 which is located between member 36 and the top lip
of container 16.
Member 86 is bolted to assembly 30 in such a manner
that a space is provided between member 86 and the lip portion
90 of lid assembly 30. ~his is provided by a series of raised
rib portions on the upper surface of member 86 which engage
lip portion 90.
Member 86 is provided with a "Vee" shaped abutment
92 on the lower surface 84 thereof (see Figure 2). The abut-
ment 92 is of ~uch depth that the lower surface of the abut-
ment 92 is parallel to and only slightly above the opening
surface of elbow member 78.
Situated between the legs of the "Vee" shaped abut-
ment 92 is a semicircular boss 106 which also extends down-
: wardly from surface 84. The forward half of the circumferenceof boss 106 is solid and impervious to air flow, thus acts~s an additional baffle and extends downwardly to a greater
extent than the rearward semicircular portion. A wire mesh
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filter screen completes the rearward portion of boss 106
facing to the open end of the "Vee". Note the shallow boss
on the rearward semicircular portion between the screen and
sur~ace 84. ~he resulting structure is such as to produce a
circular container with a solid bottom formed in such a
manner as to captivate "panca~e" shaped member 104 therein,
in such a manner that member 104 may freely mo~e up and down,
but is constrained from any substantial lateral motion.
"Pancake" shaped member 104 is made from a material such that
it will ~loat in water~ In the center of boss 106, an aper-
ture 108 is provided to allow pas~age o~ air from compartment
80 into the vacuum pump intake 110.
~id member 86 is pulled by ~astening members 114 into
engagement with lip 90 and sealing engagement with the lower
sur~ace of housing 38. A suitable sealing member 116 is pro- -
vided for this function. Aperture 108 is in communication
with aperture 118 in the lower sur~ace of fan housing 38
which is the intake for the vacuum pump assembly. From aper-
ture 118, air is drawn into fan impeller 36 and is subsequent-
ly expelled through a series of apertures 120 in housing 38.
Exhaust air passes into space 44 and exits through space
provided between lip 90 of housing 33 and member 86.
~he air/liquid mix drawn into chamber 80 passes from
elbow member 78 and deflects upwardly, ~uch that the li~uid
droplets deposit on lower surface 84 o~ member 86, immediately
above the opening in member 78
It is at this location that substantial separation
of the air/liquid mixture takes place, with the air taking a
rather circuitous route from the exit aperture in member 78,
up against sur~ace 84, past abutment member 92 through screen
106, through aperture 108 and thence into the ~acuum pump,
out apertures 102, into space 44, and thenc~ out through the
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space provided between lip 90 and member 86. The space
provided for allowing the discharge air from the vacuum
pump extends virtually the entire distance around the
periphery of lid member 30 immediately below lip 90.
~his assures plenty o~ area for the entire discharge orifice
and consequently ~uietens the overall operation of the
machine.
During usage of the machine, container 16 gradually
~ills with the liquid/soil residue, w~ilst air (the carrier)
passes through the machine. As the level o~ the liquid/soil
mixture rises, "Pancake" shaped member 104 is floated upwards
in its cage assembly 102 until the rush of air past the
"Pancake" shaped member 104 raises it to maximum height with
the subsequent blockage o~ aperture 108. No further passage
o~ air through the machine is permitted in this condition
and further vacuuming ma~ be resumed when container 16 has
been emptied.
In instances where the machine is intended to be
employed as a dry vacuuming machine only, a paper or cloth
filter bag 120 m~ay be placed over elbow member 82. ~his
pre~ents the pas~age of ~oreign material into the fan housing
38 ~nd vacuum cleaning proceeds as it would wlth a standard
dry vacuum cle~ner.
In operation, lid member 30 is hinged at 140 to
stationary members 142 so that member 30 may be raised and
pivoted over member 14 to allow container 16 to be removed
from the wagon 12. Also,~a cover 144 is provided for con-
tainer 14. ~his cover will remain in place at ~11 times a~d
the liquid detergent solution will be placed in container 14
by means of aperture 146 in the lid 144.
lhe two wagon sections 12a and 12b are pre~erably
held together by a bolt or other fastening me~ns 150 SG as to
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enable swift disassembly of the wagon for repair or main-
tenance procedures.
A pair of switches 152, 154 are provided to enable
operation o~ the vacuum motor 32 and the liquid pump 22
separately, for more versatile machine operation, i.e. the
pump need not operate when only dry vacuuming.
~ he wand 70 and sprayer 28 m~y be physically coupled
together ~or most wet cleaning operations to enable simul-
taneous spraying and wet pickup vacuuming.
Although this application does not describe it 9 an
electrical heating element may be employed to heat the liquid :
in the container 14. ~he power required for this feature
must be limited to 600 watts m~ximum as only a limited amount
of power may be drawn from the standard 115 volt domestic
su~ply.
~ n important feature o~ this machine is that it will
draw no more than 10 amperes from the standard 115 volt
domestic supply, as opposed to other devices of this nature
which draw up to 15 amperes and even more, thus consuming
all of the a~ailable power from a standard domestic 15
ampere circuit~ ~his means that 5 amperes of current
~approximately 600 watts) are a~ailable for lighting the
work area so that the operator may ha~e better visibility
when little or no natuxal light is a~ailable~ .
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