Note: Descriptions are shown in the official language in which they were submitted.
206~4~9
~ yrT~l ~ gAcK-PACK VACULIM CL2ANER
F TT~T.n nT~ I h V h .~, 1 ( 1
The present invention relates to vacuum cleaners
which have a harness 80 that they may be worn as a back-
5 pack by the operator. In particular, it relates to vacuumAnf~r~ of the cyclonic type.
OF ~ INVP~l-rTo~
There are various types of vacuum rl~ner~ including
upright vacuum cleaner6 and canister vacuum cleaners. An
10 upright vacuum cleaner comprises two main sections namely
a ground engaging portion mounted on wheels and a dirt
collection portion which is pivotably mounted above the
ground engaging portion . The ground ~nga~i n~ portion
includes a cleaning head and a motor. The dirt collection
15 portion includes a filtration means for separating
entrained dirt from the intake air and means for 6toring
the separated dirt.
Canister vacuum cleaner~ are substantially
cylindrical in shape and comprise a rigid outer container
20 and a hose a~sembly. The rigid outer container is mounted
on wheels for ease of v ~ ~ L. The outer container is
substantially cylindrical in shape and has a side which is
substantially circular in cross-section. The wheels may
be mounted either on the side of the container 80 that the
25 longitudinal axis of the canister extends horizontally or
on one end of the canister 80 that the longitudinal axis
of the canister extends vertically. If the unit is
horizontally disposed, the hose assemby is mounted on one
end of the outer container. A dirt filter and collector,
30 such as a bag, is positioned adjacent that end of the
container and a motor is positioned behind the dirt filter
and collector. In operation, the dirty air passes through
the hose into the dirt filter and collector and the
filtered air passes by the motor before exiting the vacuum
35 cleaner. Alternately, when the vacuum cleaner is
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vertically disposed, the motor ls mounted on top of the
outer container and the motor and/or the f ilter means may
extend into the outer container. The outer container has
an air entry port to which the hose assembly is mounted.
5 In operation, the dirty air passes through the hose into
the outer container and is then f iltered prior to exiting
the machine.
In canister vacuum cleaners a cleaning head is
attached to the end of the hose assembly distal to the
10 entry port on the outer container. This design results in
a cleaning head which is small and manouverable. However,
canister vacuum ~eitnF~r~; have several disadvantages. If
the unit is vertically disposed, the dirt will collect in
the bottom of the outer container and the air entry port
15 must be located near the upper portion of the outer
container. Otherwise, the entry port would become clogged
with dirt and this would decrease the efficiency of the
vacuum cleaner. The motor and filter ----h IniRm are mounted
near the upper portion of the canister vacuum cleaner and
20 accordingly the centre of gravity of the machine i8
relatively high. In operation, the operator typically
moves these r-~hin~ by pulling on the hose, which is
attached to the outer container. The raised centre of
gravity of the machine results in the machine being top
25 heavy and prone to tipping. Further, since a friction fit
may be used to removably mount the hose assembly in the
entry port, it is occasionally necessary for the operator
to cease operation and re-insert the hose to maintain a
hermetic seal which is loosened by pulling on the hose
30 assembly.
Accordingly, canister r-~h~n~ and in particular
vertically disposed canister vacuum cleaners, can most
conveniently be used within a circle having a radius
somewhat smaller than the length of the hose assembly.
35 Outside such a circle, the machine must be carefully moved
from position to position to avoid tipping the machine.
These machines are typically awkward to move and care is
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also required to avoid hitting and damaging walls and
furniture .
Upright vacuum cleaners have the advantage that
the motor i6 mounted in the ground engaging portion.
Accordingly, the centre of the gravity of the machine is
ad~ acent to the ground and the m-Ah i n~ are not prone to
tipping. In the past, these r--h~n~c have typically
comprised a filter --- h~n~m which may be a cloth or paper
bag. More recently, dual cyclonic upright vacuum cleaners
have been developed . These upright m~~h ~ n~c utilize
cyclonic action or centrifugal force to separate the
entrained dirt from the intake air. As is shown in
t~n;~ n Patent Nos. 1,182,613; 1,238,869 and 1,241,158,
a cyclonic vacuum cleaner may utilize first and second
cyclones which are connected in series. The first or outer
cyclone is designed to remove the larger and heavier dirt
particles which are entrained in the intake air and the
second or inner cyclone is used to remove the finer and
lighter particles which are entrained in the exhaust air
from the first cyclone.
One of the disadvantages with upright vacuum
cleaners is that during operation, the entire machine is
continually being moved by the operator. This results in
the operator ': ~ - i n~ tired. Further, the ground engaging
portion is relatively large and must be moved with care
around furniture and other obstacles. Due to its size, the
ground engaging portion may be too large to clean confined
spaces. Thus, these r-Ahin~c are often designed to accept
a hose assembly 80 that the upright vacuum cleaner may be
used in a canister mode. This results in additional design
complexities. Further, the operator must also carry around
the hose assembly. These problems are accentuated in a
commercial environment where an operator may use a machine
for several hours at one time to clean large areas.
Another type oL vacuum cleaner is the back-p~ck
vacuum cleaner. Examples of such m-^h i nF~ are the QUARTER-
VAC, the MEGAVAC, the POCKET VAC, the OPTIMUS 1 and the
2~61469
,
LINEVACER . These r~~h i n~s have a upper portion which
contains a filter bag or other filter medium. The motor is
located ad~acent the bottom of the vacuum cleaner below
the filter means. The hose assembly is connected to the
5 top of the machine so that the intake air passes from the
top of the machine through the filter means, past the
motor and i8 then exhausted from the machine.
Back-pack vacuum cleaners have been used in the
commercial environment, and accordingly they must be worn
10 by the operator for several hours at a time and, possibly,
for an entire shift. Due to the nature of existing
designs, these r^-hinF~ feel heavy and uncomfortable and
accordingly they are not desirable for extended hours of
use .
15 Sl]l5~1ARY OF T~R lhv~ ON
It has been found that these disadvantages can
be overcome by using a cyclonic vacuum cleaner which
comprises a back-pack harness, an upper casing attached to
the harness, a lower casing releasably mounted on the
20 upper casing, at least one cyclone mounted with at least
the lower part thereof positioned within the lower casing,
a motor positioned within the upper casing above the at
least one cyclone, an air entry means providing an air
flow path from outside the vacuum cleaner to the at least
25 one cyclone and an air exit means providing an air flow
path from the at least one cyclone to outside the vacuum
cleaner .
Preferably, the vacuum cleaner comprises a first
cyclone and a second cyclone in series. The inr; In9 air
30 enters the first cyclone and passes from the exit of the
first cyclone to the entrance of the second cyclone. The
air exits from the second cyclone and preferably is used
to cool the motor which is located above the exit from the
second cyclone. The air entry means may comprise a port
35 for supplying dirt laden air tangentially to the first
cyclone to produce cyclonic rotation of the dirt laden air
within the first cyclone. The air entry port may be
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located near the top of the first cyclone.
The lower casing may comprise the outer wall of
the first cyclone and the air entry port may be positioned
at the upper portion thereof. The lower casing may be
substantially circular in cross-section such that the
lower casing may be rotated relative to the upper casing
thus permitting the air entry port to be positioned either
on the right hand side or the left hand side of the vacuum
cleaner to permit ease of use by a right handed operator
or a left handed operator.
The air exit means may comprise one port on the
upper part of the casing. The exit port may be positioned
and configured to direct air flow away from the operator.
Further, the exit port may be adapted to receive a hose so
that the vacuum cleaner may also be used as a blower.
Alternately, or in addition, the exit port may be adapted
to receive a filter such that, after passing through said
filter, over 9996 of O . 3 micrometer size particles have
been removed from the incoming dirt laden air.
In contrast to prior vacuum cleaners, this
design provides a vacuum cleaner which is ~9~ i r . The
vacuum cleaner i8 easy to operate and light weight 80 that
it may be worn for an extended period of time by the
operator. Further, the vacuum cleaner has an improved
filtering --- h~niPm while maintaining a light weight
des ign .
The substance and advantages of the present
invention will be more fully and completely described in
accordance with following description, and the
~cc~ ~-nying drawings, of a preferred embodiment of the
invention .
sRIEF r~r~RTpTIQ~ OF ~ TNvRN~
Figure 1 is a perspective view of a vacuum
cleaner according to the lnvention, when worn by an
operator;
Figure 2 is a perspective view of the front of
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the vacuum cleaner of Figure l;
Figure 3 i8 a perspective view from the rear of
the vacuum cleaner of Figure 1 with the lower c~sing
removed; and,
Figure 4 i8 a cross-section along line 4-4A of
the vacuum cleaner of Figure 3.
Figure 5 is an exploded view of the after filter
shown in Figures 1-4.
nR~ATT-Rn r~R-C~'RTPTIQN OF ~ RMR~nTMRr~
As shown in Figure 1, vacuum cleaner 10
comprises a harness 12, an upper casing 14 and a lower
casing 16. The vacuum cleaner is adapted to receive a hose
assembly 18. Hose assembly 18 may be of any desired length
and, preferably, is designed to receive a variety of
interchangeable cleaning heads as may be required.
The back-pack harness may be of any design known
in the art. Harness 12 has a back plate 20, two shoulder
straps 22 and a waist strap 24. Male and female buckle
members 26 and 28 are fixed at the two ends of waist strap
24. sack plate 20 extends from a point near the top of
upper casing 14 to a position ad~acent the central portion
of lower casing 16. The back plate is dimensioned and
c~nf i gllred 80 as to be comfortably mounted on the back of
the operator. Shoulder straps 22 are individually ad~usted
by means known in the art to mount the vacuum cleaner at
the proper height for each operator. Similarly, waist
strap 24 is ad~ustable 80 as to fit around the waist of
any operator.
In use, the operator may easily put on the
vacuum cleaner and ad~ust it to fit their body. The
operator places his arms through shoulder straps 22 and
secures waist strap 24 by inserting male buckle member 26
into female buckle member 28. The shoulder straps and
waist straps may then be ad~usted to fit the operator.
Upper casing 14 has a side wall which is
substantially cylindrical. The upper ca8ing may be
attached to the harness by numerous means. As shown in the
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Figures, two protrusions 30 extend outwardly from a
position near the front of cylindrical housing 14. Back
plate 20 may be secured to these protrusions by any means
known in the art. A8 shown in Figure 2, back plate 20 is
secured to protrusions 30 by means of a plurality of
screws 32.
The electric cord 34 may be attached to upper
casing 14 at any desired point. It has been found
advantageous to attach electric cord 34 to one of the
protrusions 30. This results in the electrical cord being
positioned at a point where it does not interfere with the
of the ho~e assembly but where it may be easily
grasped by the operator. On/off switch 36 is attached to
upper housing 14 by means of control cord 38. By using a
control cord, the vacuum cleaner may easily be turned on
and of f by the operator while wearing the vacuum cleaner .
Similarly, as with the electric cord, the control cord may
be attached to the vacuum cleaner at any desired location.
Once again, it has been found advantageous to locate
control cord 38 on one of protrusions 30. If desired, an
electrical outlet (not Ehown) may also be provided on
protrusion 30. This would be advantageou~ if a VA.-llllmin~
head having an electrically driven motor were to be
attached to the vacuum cleaner.
Air exit port 40 is located near the top of
upper casing 14. A8 shown in Figure 1, air exit port 40 is
positioned and configured to direct air flow away from the
operator. The upper portion of upper casing 14 comprises
a bevelled surface 42 and a top 44. I~hile air exit port 40
is positioned on bevelled surface 42 in the Figures, by
suitably adapting the conf iguration of the air exit port,
the air exit port may be positioned at an alternate
location on bevelled surface 42 or on top surface 44.
Preferably, air exit port 40 is adapted to
receive a hose. By this ~l~f~l-Ation, the vacuum cleaner
may be tran~formed into a blower. This expands the
potential use of the vacuum cleaner.
- 8 _ 20~ 9
The use of dual cyclones in a vacuum cleaner
results in a high level of particulate removal from the
entrained air, including relatively small particles.
However, when used in a toxic environment or in a clean
5 room, the particulate emissions from vacuum cleaners must
be exceptionally low, for example in the order of 99 . 99~
of 0 . 3 micron particles. To meet this requirement, an
after-f ilter may be installed on vacuum cleaner 10 . This
may be accomplished by adapting air exit port 40 to
10 receive a filter. Preferably, the filter is positioned
F~xt~rn;l 1 to the upper casing . As shown in Figures 3 and 4,
the after filter comprises a conical bottom portion 100,
a top portion 102 and a filter 104. Bottom portion 100
has a base 106 which is securely attached to air exit port
15 40. Due to the pressure which builds up in the filter,
the filter must be securely fixed to port 40. A suitable
means of rPl~ hly securing the filter to air exit port
40 is by use of a boyonet mount 108. The exact size and
shape of filter 104 will vary d~r~n~lin~ upon the
20 particular emission standards which are set for use in
various instances. However, by the use of an after-filter,
it is possible to remove over 99 . 99~ of 0 . 3 micron size
particles form the dirt laden intake air. As shown in the
Figures, filer 104 is in the shape of an annulus. Top
25 portion 102 has a plurality of circumferentially spaced
vents 110. In operation, the air enters through base 106
and passes into the centre of filter 104. The air passes
through filter 104 and exits through vents 110.
By this modification, an after-filter may easily
30 be added when required. The after-filter is a high
efficiency and, preferably, high air flow filter. An
example of a suitable f ilter material is HEPA or IrLPA
brand filter media. This material is an expensive
synthetic material. By positioning the filter after the
35 dual cyclones, the exhaust air has been substantially
cleaned by the time it reaches the f ilter . This greatly
increases the filter life. Further, the filter will act to
9 2~4~9
an extent as a muffler to decrease the noise from the
motor .
Lower caslng 16 is r~ R~hly mounted on upper
casing 14 by any means known in the art which provides a
5 hermetic seal. In the preferred ~o~ , latches 46 are
provided ad~acent the lower portion of upper casing 14.
One latch may be positioned on either side of upper casing
14. Each latch 46 ha~ an arm 48 which is pivotably mounted
to the upper casing 14. The distal end of each arm 48 has
10 a hook 50. This hook is designed to engage with rim 52 of
lower housing 16. When lower casing 16 is mounted on upper
casing 14, latches 46, in con~unction with rim 52, result
in an air tight seal which avoids any pressure drop in the
cyclone c~h ''`rR.
Lower casing 16 has a receiving chamber 54
positioned ad~acent its lower portion 66. Purther, air
entry port 56 is positioned adjacent the upper portion of
lower casing 16. Air entry port 56 is configured to supply
dirt laden air tangentially to the interior surface of
20 lower casing 16. Air entry port 56 is configured to
receive hose assembly 18.
Since air entry port 56 is positioned on lower
casing 16, the air entry port may be positioned either on
the left hand side or the right hand side of the unit
25 simply by rotating lower casing 16 relative to upper
cas$ng 14 prior to engaging latches 46. By this
ad~ustment, the vacuum cleaner may be used either by a
right handed operator or a lef t handed operator .
~he vacuum cleaner has a cyclonic cleaning
30 assembly. Cyclone assembly 60 is mounted on upper casing
16 such that at least the lower part of the as~embly is
positioned within the lower casing 16. Preferably, as
shown in Figure 3 substantially all of cyclone assembly 60
is positioned within lower casing 16. Cyclone assembly 60
35 may be of any cyclone design which is known in the art of
vacuum cleaners and compri~es at least one cyclone.
Preferably, the cyclone assembly comprises a first cyclone
lO- 20~469
chamber and a second cyclone chamber in series and, for
compactness, it is preferred to have the two cyclones
mounted coax~ y as shown in Figure 4. Referring to
Figure 4, the f irst cyclone chamber is denoted by
reference numeral 62 and the second cyclone chamber is
denoted by reference numeral 64. The air enters the vacuum
cleaner via air entry port 56. A centrifugal force is
applied to the dirt laden air causing the dirt laden air
to rotate within first cyclone chamber 62. The larger and
heavier dirt is deposited in the lower portion of lower
casing 16 (denoted by reference numeral 66). The air exits
from the first cyclone chamber via first cyclone air exit
68 to passage 70. The air travels through passage 70 to
second air entry port 72. Second air entry port 72 imparts
a tangential flow to the air causing the air to circulate
in a cyclonic pattern within second cyclone chamber 74.
The finer dirt particles are deposited in receiving
chamber 54 and the cleaned air is evacuated from the
second cyclone chamber through second cyclone air exit 74.
Notor 80 is positioned within upper casing 14
above the cyclone chambers. Motor 80 may be mounted to
upper casing 14 by any means known in the art which
dampens vibrations from the motor. As shown in Figure 4,
a plate 82, which is part of the upper casing, is
positioned on top of the cyclone chambers. The plate seals
the cyclone ~h ` ~ to prevent any pressure drop. Second
cyclone air exit 74 is positioned at the centre of plate
82. Rubber gasket 84 is positioned above plate 82. Motor
80 is then positioned on top of rubber gasket 84. The
gasket prevents air leakage between the motor and cyclone
air exit 74 and provides shock absorbing so as to dampen
vibration from the motor. Cap 86 is placed on top of the
motor and the entire assembly is secured into place by
means of z-shaped clamp 88. Clamp 88 is secured to upper
casing 14 by means of lower screw posts 90 and upper screw
posts 92.
This conf iguration provides several advantages .
.
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Flrst, by locating the motor at the top of the vacuum
cleaner, the el~, iC5 are subgtantially i uv~d. It has
surprisingly been found that the use of this configuration
provides a vacuum cleaner which feels very light weight
5 and comfortable to the operator. This is achieved in part
by mounting the motor at the top contrary to what has been
utilized in previous designs. With the bulk of the mass of
the vacuum cleaner (the motor) at the top, the unit is
more securely held to the operator 8 back and tends to
lO swing less and have less free motion than if the motor
were at the bottom. This design results in the motor being
substantially closer to the operator 8 ears than those
utilized in previous designs. Despite this clo~c~n~P~ it
has also surprisingly been fûund that the design is
15 relatively quiet and may be used for extended periods of
time without the need to apply expensive sound absorbing
insulation to the upper casing. The sound level can be
further reduced, as mentioned, by using a filter at air
exit 40. Further, by positioning motor 80 directly above
20 second cyclone air exit 74, the clean air may be used to
cool the motor.
