Note: Descriptions are shown in the official language in which they were submitted.
~27~653
SURFACE CLEANING APPLIANCE
The invention relates to a surface cleaning
appliance for the removal of dust from solid objects, in
particular for the preliminary cleaning of surfaces prior
to painting.
Despite intensive preliminary cleaning and dust
removal prior to the industrial painting of objects,
surface paint layers are frequently found to have
inclusions of dust particles which necessitate considerable
follow-up work. Such fouling is essentially due to
inadequate cleaning. The currently used manual method for
the removal of dust prior to the painting process is
conducted in two stages: Dust is blown off the surface to
be cleaned using compressed air at ca. 5 bar and the
surface is then rubbed down with dust-binding and~or damp
cloths or special gloves. In so doing, on the one hand, as
a result of the high air pressure, dust particles are
whirled up and thereby settle once again on the cleaned
areas. It is consequently senseless to blow dust off
surfaces above a certain size with compressed air. Manual
cleaning, on the other hand, provides no guarantee that all
areas of the surface to be cleaned are treated. Through
constant wiping of the surfaces and the resultant friction,
an electrostatic charge is moreover created which causes
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the dust particles to adhere to the surfaces. A further
disadvantage is that the cleaning staff cannot perceive the
dust particles
which are present, due to the colour of the undercoat, the
primer or the filler.
u.s. patent specification No. 4 454 621 describes a
cleaning apparatus with means for blowing ionized air and
for sucking away neutralized particles which is specially
designed for the continuous cleaning of both sides of bands
or webs. The arrangement described is, however, not
suitable for the cleaning of solid objects of various
shapes and dimensions such as, for example, motor vehicle
bodies.
The object of the invention is to provide a surface
cleaning appliance which permits the rapid, thorough
removal of dust from various solid objects with little
effort and which largely overcomes the above-described
disadvantages. This object is achieved by a surface
cleaning appliance having the characteristics set out in
the claims.
The surface cleaning appliance according to the
instant invention essentially comprises an air blowing
nozzle having a narrow, obliquely arranged linear blowing
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slot, which is operativel~ associated with an ionizin~
device, an air suction nozzle ha~ing a linear suction slot
and with a baffle in such a manner that it emits a thin,
flat laminar jet of air at high velocity which sweeps
intensively over the surface to be cleaned and is then
sucked up through the linear suction slot.
The surface cleaning appliance is provided according
to the instant invention with a baffle which serves to
provide contact with the surface to be cleaned and to
maintain the appliance at a distance therefrom, while it
advantageously consists of a flat protective brush and is
operatively associated with the linear suction slot so that
it largely prevents sucking in of the surrounding air while
it defines the laminar jet of air so that it is sucked up
through the suction slot after sweeping over the surface to
be cleaned.
.
This brush is preferably a toothed strip brush and fulfills
various functions in accordance with tho invention: firstly
it serves as a baffle and distance piece or spacer in order
to define and delimit the laminar air jet and to thereby
achieve an optimal cleaning effect while to a large extent
avoiding the sucking up of surrounding air. Secondly, it
serves as a protective brush to avoid any damaye to the
surface to be cleaned or to the appliance. Furthermore, by
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means of this brush, adhering and moist dust may be
mechanically detached from the surface to be cleaned and
then sucked up.
In order to ensure the delivery of a laminar jet of air,
the air blowing nozzle is dimensioned, adapted to the
de~ired air speed and advan-tageously provided with inner
guide surfaces so that the air jet is evenly distributed
and directed obliquely so that no turbulence is created in
the air jet. By means of an air blowing slot having a very
narrow aperture, which generally amounts to less than 1 mm
and preferably less than 0.5 mm and, for example, 0.2 to
0.3 mm, the air stream may be directed through the linear
blowing slot in the form of a flat, very thin, laminar jet
of air over the entire length of the slot at a slight
overpressure of less than 1 bar, preferably below 0.5 bar,
with a relatively short jet length and be delivered at an
oblique angle to the surface to be cleaned in order to
ensure a laminar flow along this surface. The blowing air
may be producet in a ring comprossor located outside the
cleaning appliance and fed to the blowing air nozzle via a
low pressure hose, while the suction air is conducted from
the air suction nozzle by means of a suction hose.
The length and shape of the suction slot are, on the
other hand, adapted to the air blowing slot and arranged
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~7~ 3
that the air suction no~zle is able to suck away a somewhat
larger ~mo~lnt of suction ~ir than the amount of the air jet
delivered, without appreciable loss of pressure. The
suction ~ir is advantageously delivered to a high
performance filter, whereby cleaned air is supplied to the
suction side of the compressor and delivered there~y to the
air blowing nozzle.
The ~hape and dimensions of the blowing slot and of
the suction slot are in each case adjusted to one another
and may be adapted to the nature of the cleaning work
required. For this purpose, on the one hand, the air
blowing nozzle and the air suction nozzle may be equipped
with various extension attachments. On the other hand they
may also be provided with means for adjusting the length of
the blowing slot and of the suction slot, whereby these
slots may be adjusted individually or jointly, by hand or
using a motor. An adjustable slot width may, furthermore,
be achieved for the biowing slot or for the suction slot
through the incorporation of appropriate adjusting means,
while means for the mechanical fine adjustment of the slot
width may be provided.
The special combination in accordance with the
invention of a blowing nozzle having an obliquely disposed,
narrow linear blowing slot operatively associated with an
786~3
ionising device for the delivery of a uniform, ionized
laminar jet of air, with a suction nozzle having an
appropriate suction slot and with a baffle, thus provides
highly effective, rapid and thorough cleaning by means of
the precisely defined flat, ionized laminar air jet which
is precisely defined and limited by the appliance, the
blowing slot, the suction slot, the baffle and the surface
to be cleaned, and which vigorously sweeps over, and
cleans, this surface at high velocity and with minimal
creation of turbulence and sucking-in of surrounding air.
The cleaning appliance according to the invention is
passed by hand or ~echanically along the contours of the
object to be cleaned. sy means of the laminar, ionized jet
1S of air, dust particles adhering to the surface are detached
and blown to the suction slot, while practically no
turbulence is caused by this action, and the detached dust
particles are immediately taken up and removed by the
suction slot. In so doing, the appliance is yuided so that
the brush is always kept in contact with the surface to be
cleaned in order to fulfil its designated special functions
as baffle to maintain distance and to limit the laminar
flow and the sucking away of air from the cleaning gap,
whereby adhering and moist dust may be caught up by the
brush, mechanically detached and sucked away.
1'~78653~
The invention will now be described hereinafter with
reference to examples of embodiment.s and to the appended
drawings.
Figure 1 shows a schematic section through a median
plane of a portable surface cleaning appliance according to
the invention.
Figure 2 shows a schematic section through a median
plane of an industrial surface cleàning appliance according
to the invention.
Figure 3 shows a schematic partial plan view of the
industrial cleaning appliance of Figure 2.
The portable cleaning appliance of Figure 1
comprises a housing 14 having a handle 15 for carrying and
guiding the appliance, an ineorporated blowing air nozzle 1
with an obliquely arranged linear blowing slot 2 on the
underside of the appliance, an ionizing device 7 also built
into the appliance and operatively associated with the air
blowing nozzle 1, a suction nozzle 3 having a suction slot
4 which is disposed at a short distance X from the blowing
slot 2 on the underside of the appliance and a flat brush
5, preferably a toothed strip brush, which is disposed next
to the suction slot 4 and projeets from the underside of
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the appliance at a height H in relation to the outlet of
the blowing slot 2. The brush 5 is fixed to the appliance
by suitable means, not shown in further detail, which make
it possible for it to be replaced and for its height ~ to
be adjusted as required.
The air blowing nozzle 1 is connected to an
incorporated air blowing duct 9 having an inlet 10 with a
projecting part 11 for connection to a blowing air hose 16,
indicated in broken lines, which serves to supply low
pressure air. The suction nozzle 3 is further linked to an
incorporated suction air duct 12 having an outlet 13 with a
projecting end-piece 17 for connection to a suction air
hose 18 indicated in broken lines, which serves to suck up
the cleaning air at an adequate vacuum.
The air blowing air nozzle 1 and the blowing slot 2
are so dimensioned and designed that a flat, laminar jet of
air is delivered at high speed through the blowing slot 2.
As may be seen in Figure 1, the blowing slot 2 is obliquely
disposed with respect to the suction slot 4 and to the
underside of the appliance so as to be able to direct a
laminar jet of air at a small, acute angle onto the surface
to be cleaned, which is in contact with the lower, free end
of the brush 5 at the height H and will limit the cleaning
gap parallel to the underside of the appliance.
8653
g
The mode of operation of the described portable
cleaning appliance as shown in Figure 1 may be explained as
follows:
In use, the portable cleaning appliance is held by
the handle 15 and guided along the surface to be cleaned in
such a way that the free end of the brush 5 is always
maintained in contact with said surface. In so doing, the
brush 5 shall be held perpendicular to said surface so that
the underside of the appliance is parallel to the surface
to be cleaned. The height H of the brush 5 thus determines
the desired distance between the underside of the portable
appliance and the surface to be cleaned and defines
therewith a narrow cleaning gap which encloses the laminar
jet of air delivered by the blowing slot 2. The air jet rnay
thereby be maintained with a laminar flow of high velocity
along the surface to be cleaned through the cleaning gap,
while the brush 5 laterally limits this cleaning gap,
determines the width of this gap and largely prevents an
undesirable sucking-in of surrounding air. This high-speed
laminar jet can thus vigorously sweep over the surface to
be cleaned, detach and carry along dust particles present
thereon, then be immediately caught by suction and sucked
up with the detached dust particles. The incorporated
ionizing device 7 makes it possible to continuously
786~3
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generate positive or negative ions in the blowing air jet.
Electrostatically charged particles located on the surface
to be cleaned may thus be neutralized, detached and removed
by means of the ionized blowing air jet.
s
The air blowing nozzle and the suction nozzle of the
portable cleaning appliance of the invention may be of
variable width and may be operated by appropriate
mechanical adjusting means, e.g. with the aid of
articulated arms and a gear drive either by hand or with a
motor in order to adjust the width of both nozzles
ir.dividually or together as required. The blowing slot and
the suction slot of these nozzles may, moreover, be
equipped with adjustable guide lips or other suitable means
in order to vary their gap width as required. For this
purpose mechanical fine adjustment of the gap width may be
possibly provided. Moreover, additional brushes may be
provided on the`cleaning appliance in order, for example,
to laterally limit the laminar flow of the jet of air so as
to prevent surrounding air from being sucked in from the
side.
In addition, the portable cleaning appliance of the
invention may be fitted with sensors and display means in
order, for example, to permit a display of the
counterpressure on the brush, a display of air pressure for
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the purpose of optimi~ing the blowing air - suction air
balance or a display of the positive or negative charge on
the surface.
Various materials may be used in the manufacture of
the cleaning appliance of the invention. For this purpose
various plastic materials may advantageously be used in
order, inter alia, to make the appliance as ligh~weight as
possible. Moreover, various parts of the appliance may be
manufactured from any suitable metal.
The portable cleaning appliance of the invention
possesses many advantages, for example, it is simple to
handle, has many possible uses with relatively low
purchasing costs, minimum weight and very little space
requirements. Moreover it appreciably simplifies and saves
the effort involved in cleaning work, whilst avoiding the
already mentioned follow-up work during painting. At the
same time, it imposes no burden on the environment.
The industrial surface cleaning appliance according
to Figures 2 and 3 comprises a connection 20 with a take-up
centre 21 for mounting and revolving the appliance. The
industrial cleaning appliance shown in Figure 2 comprises
an incorporated air blowing nozzle 1 with an obliquely
disposed blowing slot on the underside of the appliance, an
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ionizing device 7, which is operatively associated with the
air blowing nozzle 1, a two-part toothed strip brush 25
disposed at a distance z and z from the blowing air
nozzle 1, divided and offset in the middle and an obliqu~ly
S disposed air suction nozzle 3 having a suction slot 4 which
is located at a short distance X from the strip brush 25,
which projects in front of the air suction nozzle 3 from
the underside of the appliance at a height ~ in relation to
the entry edge of the suction slot 4 and the underside of
the appliance. The ~trip brush 25 is fixed to the appliance
by means of appropriate means, not shown in further detail,
which make it possible, on the one hand to impart thereto
an oscillating movement and, on the other hand, to replace
them and to adjust their height H as re~uired.
The air blowing nozzle is linked to an incorporated
air blowing duct 29 having an inlet 30 with a projecting
part 31 for connection to an air blowing hose 16, shown in
broken lines, which serves to supply compressed air. The
suction nozzle is, in addition, linked to an incorporated
suction air duct 32 which is linked to the connection
pieces 33 leading to a central tube 34. This tube 34 has an
outlet 35 with a projecting end-piece 36 for connection to
a suction air hose 18, shown in broken lines, which serves
to suck up the cleaning air with an adapted vacuum.
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The air blowing nozzle 1 ancl the blowing slot 2 are
so dimensioned and designed that a flat, laminar jet of air
is delivered through the blowing slot 2 at high velocity,
corresponding pressure and appropriate range. As shown in
5 Figure 2, the blowing slot 2 is disposed obliquely so that
it can direct the laminar jet of air at the appropriate
acute angle herefor onto the surface to be cleaned.
The mode of operation of the industrial cleaning
appliance shown in Figures 2 and 3 may be described as
follows:
The industrial cleaning appliance is swivel-mounted
for use on the pick-up centres 20,on the right and left of
the machine and guided by means of control elements to
follow the surface to be cleaned in such a way that the
free end of the strip brush 25 is always maintained in
contact with this surface. The height H of the strip brush
25 thus determines the desired distance between the
underside of the industrial cleaning appliance and the
surface to be cleaned and limits therewith the cleaning gap
which encloses the laminar jet of air given off by the
blowing slot 2. This makes it possible to maintain the jet
of air with a laminar flow of high velocity along the
surface to be,cleaned through the cleaning gap, while the
strip brush 25 limits this gap, determines its clearance
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and prevents an undesirable, premature sucking up of the
laminar jet of air. The laminar flow with corresponding
velocity can thus vigorously sweep over the surface to be
cleaned, detach dust particles present thereon and collect
and be sucked off through the strip brush 25 together with
the dust particles. The ionizing device 7 continuously
produces ions in the laminar jet of air so that
electrostatically charged particles present on the surface
to be cleaned may be neutralized, detached and removed by
the jet of air.
The blowing slot of the blowing nozzle and the
suction slot of the suction nozzle may, in addition, be
equipped with adjustable guide lips in order to vary their
clearance as required. For this purpose it is possible to
provide a mechanical fine adjustment of the slot clearance.
The ionizing device operatively associated with the blowing
air nozzle may be mounted at or in the blowing air noæzle
in order to achieve adequate ionization when little space
is available.
In addition, the industrial surface cleaning
appliance may be equipped with additional strip brushes in
order, for example, to completely limit the laminar flow of
the jet of air laterally and to prevent sucking in
surrounding air from all sides.
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In addition, the industrial surface cleaning
appliance of the invention may be fitted with sensors and
display means in order, for example, to permit display of
the counterpressure on the brush, an indication of air
pressure in order to optimize the blowing air - suction air
balance or the display of the positive or negative charge
on the surface.
The industrial surface cleaning appliance according
to the invention has various advantages. For example it is
suited, for mechanical or automated handling, can cover a
precisely defined surface sweeping area, has manifold
possible applications in automatic production cycles prior
to further processing of the products, is environmentally
harmless, provides safety at the workplace, presents the
possibility of incorporation into existing production lines
and may be used`as an independently operating system.
The obliquely disposed linear blowing clot of the
blowing air nozzle according to the invention is directed
at an acute angle of position of, for example 25 to 60
on the surface to be cleaned so that the laminar flow
of the jet of air given off from the blowing slot may be
ensured on the surface to be cleaned. For this purpose the
blowing slot is disposed at an appropriate angle with the
~Z786~;3
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underside of the appliance and with the median plane of the
suction slot and is appropriately dirnensioned. The laminar
flow is, moreover, ensured by the height of the baffle, or
the strip brush which limits between the blowing slot and
the underside of the appliance and the surface to be
cleaned a cleaning slot gap that is as narrow as possible.
The gap clearance and the distance of the blowing slot
outlet from the surface to be cleaned is maintained by the
baffle or the brush and is advantageously at least ~ mm in
order to prevent the appliance coming into contact with
this surface. This distance is advantageously 5 to 10 mm,
while it may if necessary be increased to 20 to 30 mm.
