U.S. patent number 3,889,636 [Application Number 05/319,381] was granted by the patent office on 1975-06-17 for coating of substrates with particle materials.
Invention is credited to Willoughby Arthur Smith.
United States Patent |
3,889,636 |
Smith |
June 17, 1975 |
Coating of substrates with particle materials
Abstract
Apparatus for electrostatically applying a coating of a particle
material to a substrate surface to which a settable adhesive has
been applied, including a container for the particle material which
can pass gravitationally to a power-driven agitating and metering
device and through an electrostatically chargeable electrode from
which the charged particle material can then pass downwardly
through a main discharge opening to the substrate surface, or said
main discharge opening can be closed and the charged particle
material can then be fed by the agitating and metering device to an
air operated injector device from which the particle material can
be delivered through a flexible pipe to a portable handle device to
which different subsidiary discharge heads can be applied and
electrostatically charged electrodes are positioned at or adjacent
subsidiary discharge head openings to again charge or boost the
charge applied to the particle material prior to discharge towards
the substrate surface.
Inventors: |
Smith; Willoughby Arthur
(Sidcot, Winscombe, EN) |
Family
ID: |
10384810 |
Appl.
No.: |
05/319,381 |
Filed: |
December 29, 1972 |
Foreign Application Priority Data
|
|
|
|
|
Aug 2, 1972 [GB] |
|
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36087/72 |
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Current U.S.
Class: |
118/621; 239/695;
118/629; 239/690; 118/627; 239/3 |
Current CPC
Class: |
B05B
5/057 (20130101); B05B 5/085 (20130101); B05B
5/1683 (20130101); B05B 7/144 (20130101) |
Current International
Class: |
B05B
5/057 (20060101); B05B 5/025 (20060101); B05B
5/08 (20060101); B05B 5/00 (20060101); B05B
5/16 (20060101); B05c 005/02 () |
Field of
Search: |
;118/621,624,627,629
;239/3,15 ;117/17.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Stein; Mervin
Assistant Examiner: Millstein; Leo
Attorney, Agent or Firm: Holman & Stern
Claims
What is claimed is:
1. Apparatus for electrostatically applying a coating of a particle
material to a substrate to which a settable adhesive has been
applied, the apparatus comprising a container for a stock of
particle material; a single metering means comprising a chamber
supplied with particle material from the container and comprising a
base and an upstanding peripheral wall, and a power rotatable
paddle wheel having blades which are adapted to sweep the volume of
the chamber on rotation of the paddle wheel and between adjacent
blades there being defined compartments, each adapted to contain a
predetermined amount of particle material, the paddle wheel having
an axis of rotation which is disposed vertically, said chamber
having two alternatively openable exits, one exit being disposed in
the base and the other exit being disposed in said upstanding
peripheral wall, a manually portable discharge head being provided
in communication with said other exit, and said one exit
constituting a downwardly directed discharge head; said single
metering means serving to meter the amount of particle material
supplied to the discharge heads; the apparatus further including an
electrostatic generator; main electrode means electrically
connected to said generator and disposed in said chamber to
electrically charge the particle material therein; and subsidiary
electrode means electrically connected to said generator and
associated with said portable discharge head.
2. Apparatus according to claim 1 wherein the main electrode means
comprises a grid extending across said one exit.
3. Apparatus according to claim 1 and including a wheeled framework
adapted to be movable over a horizontal floor surface, said
downwardly directed discharge head being spaced above the level of
the floor engaging wheels.
4. Apparatus according to claim 1 wherein a tubular connecting
passage having a flexible part is provided in communication with
said other exit and a pressure gas inlet is associated with the
passage to provide a flow of gas under pressure to carry the
particle material towards the manually portable discharge head when
the pressure gas supply is operative.
5. Apparatus according to claim 1 wherein an agitating means is
provided in the portable discharge head adjacent the subsidiary
electrode means and power driving means are drivingly connected to
the agitating means to operate same.
6. Apparatus according to claim 5 wherein the manually portable
discharge head includes a relief opening having a porous covering,
and a discharge opening spaced from said relief opening, the porous
liner enabling surplus pressure gas to escape therethrough but
preventing escape of particle material through the relief opening,
and the agitating means and subsidiary electrode means being
disposed in the path of the particle material as it passes to said
discharge opening.
Description
BRIEF SUMMARY OF THE INVENTION
According to the present invention apparatus for electrostatically
applying a coating of a particle material to a substrate surface to
which a settable adhesive has been applied, is of the kind
comprising a container for a stock of particle material, a main
discharge head affording a main discharge head opening, an
electrostatic generator, an electrode connected to the
electrostatic generator so as to be charged thereby and disposed
between the container and the discharge head opening to charge the
particle material prior to discharge thereof through said opening
wherein are the improvements comprising a metering device disposed
between the container and the discharge head opening and connected
to power operated driving means whereby the metering device is
driven to accurately regulate the flow of particle material to the
main discharge head opening in a uniform stream.
The metering device may comprise a rotatably mounted paddle having
blades between which are formed measuring chambers for the particle
material.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be more particularly described by way of
example with reference to the accompanying drawings in which:
FIG. 1 is a part-sectional side view of a floor supported part of
the apparatus including a main discharge head,
FIG. 2 is a sectional plan view of FIG. 1 on the lines 2--2
thereof,
FIG. 3 is a sectional side view on an enlarged scale of an injector
device for propelling the particle material,
FIG. 4 is a sectional side view on an enlarged scale of a handle
device for attachment thereto of a subsidiary discharge head,
FIG. 5 is a sectional side view of one subsidiary discharge head,
and
FIG. 6 is a side view of a further subsidiary discharge head.
The floor supported part of the apparatus is indicated at 10 in
FIG. 1 and comprises a frame 11 supported on floor engaging wheels
or castors 12 and supported by the frame at one end thereof is a
cylindrical container 14 of which the longitudinal axis A--A is
vertically disposed and at the top of the container is a removable
perforate or imperforate lid 16 which can be removed to enable
particle material such as fibres or granules such as of cork, wood
chips, sand or other particle materials to be placed in the
container after which the lid is replaced. At the lower end of the
container 14 is a horizontal metal electrode 18 which is of
openwork mesh formation of such dimensions as to resist the easy
passage therethrough whilst, however, permitting the passage
therethrough, of the selected particle material. The electrode 18
is connected by an electrically conductive lead 20 to an
electrostatic generator unit 22 supported at the other end of the
frame and suitably adapted to be connected to a mains electric
supply source.
An imperforate blanking panel or closure means 24 can be removably
secured to the lower end of the container 14 which is provided with
a turn-button 26 and a socket 27 to be engaged by a tongue 29 of
the panel which can be engaged by said turn-button so as to close
the lower end of the container below the electrode 18 and said
blanking panel 24 can be removed after manual release of the
turn-button so that the lower end of the container 14 can form a
main discharge head indicated generally at 28 and having a main
discharge head opening 31.
A horizontal platform 30 of the frame extends partially into the
container 14 and supports an electric motor 32 which is arranged to
drive, at variable speeds, a vertical spindle 34 of which the axis
is co-axial with the vertical axis A--A of the container 14 and
supported at the lower end of the spindle 34 is a combined
agitating and metering device in the form of a rotatable paddle 35
and composed of four radially disposed paddles or blades 36 which
are equiangularly spaced apart and each blade comprises a rigid
mounting strip 38 to which is secured a rubber or other flexible
wiper blade 40 of which the lower portion extends below the
mounting strip and the lower horizontal edge of the lower portion
wipes over in contact with or closely adjacent the mesh electrode
18. Thus four equal substantially sector-shaped measuring chambers
42 are provided between the blades of the paddle to receive the
particle material fed into the container 14.
The electric motor 32 and the upper part of the spindle 34 are
separated from the container 14 by an imperforate protective cover
43.
An opening or port 44 is formed in a side wall of the container 14
adjacent the lower end thereof and, at least in main, is below the
upper horizontal edges of the paddles 36 so that said opening or
port is disposed horizontally opposite the measuring chambers 42 as
the paddles 36 sweep across said opening or port in fairly close
proximity thereto. The opening or port 44 can be closed by a
control means in the form of a vertically movable slide 46 when
said slide is manually moved downwardly and said port can be opened
by manually moving the slide 46 upwardly in which upper position
the opening or port is placed in communication with the interior of
the chamber 14.
In order to apply a coating of particle material to a substrate
surface such as the floor surface 48 or a sheet of any suitable
material resting thereon, said surface has applied thereto a
suitable settable adhesive and, after the container 14 has been at
least partially filled with the particle material and the blanking
panel 24 has been removed and the opening or port 44 has been
closed, the electric motor 32 is started whereby the agitating and
metering device 35 is rotated at a speed adjusted to suit the
particular particle material and the electrode 18 is
electrostatically charged and the particle material passes
downwardly under gravitational compulsion through the electrode 18
so that a stream of electrostatically charged particles pass
vertically downwardly and are attracted to the substrate surface 48
so as to coat said surface and form a part thereof after the
adhesive has set. The entire substrate surface can easily be coated
with the particle material by manually propelling the ground
supported apparatus 10 over said surface by handle means 49.
In order to apply a coating of a particle material to a substrate
surface, after a settable adhesive has been applied thereto, such
as for example a vertical wall surface or a ceiling surface, the
portable subsidiary discharge head illustrated in FIG. 6 may be
employed.
For this purpose there is mounted in the floor supported part 10 an
air operated injector device 50, see FIGS. 1 and 3, which comprises
a tubular nozzle 51 which is screwed at one end into the container
14 and the bore of the nozzle affords the opening or port 44. The
other end of the nozzle 51 is externally convergent, as indicated
at 52, in an arcuate manner and an internally screw-threaded sleeve
53 is engaged with an externally screw-threaded part of the nozzle
51 so that an annular suction chamber 54 is provided within the
sleeve and surrounding the convergent part 52 of the nozzle. As
outlet pipe 55 is screwed into the bush 53 and is adjusted
longitudinally thereof and locked in position by a lock-nut 56 so
as to leave a gap 57 between the nozzle 51 and the outlet pipe 55
and the width of said gap 57 can be adjusted to suit various
circumstances including the nature of the particle material being
used.
An inlet nipple 59 is screwed into the sleeve 53 so that the bore
of the nipple communicates with the annular suction chamber 54 and
said nipple is connected by a flexible hose 58 to a power operated
air compressor indicated at 159 mounted on the platform 30 of the
frame 11 so that a current of air under pressure can be fed into
the air injector device 50 and the air passes around the chamber 54
and is directed by the convergent part 52 of the nozzle through the
gap 57 and into the bore of the outlet pipe 55 whereby suction is
created in the bore of the nozzle 51 and thus at the opening or
port 44 so that particle material can be drawn into the injector
device from the container 14 when the slide 46 has been manually
moved upwardly into a position opening said port 44 and the
blanking panel 24 has been secured to the lower end of said
container 14 to close the main discharge head opening 31. During
the suction effect exerted by the injector device 50 on the
particle material in the container 14, the combined agitator and
metering device 35 is rotated at a suitable speed for the material
so that said material is agitated and delivered to the opening or
port 44 in a metered or controlled manner at a constant rate and
before entering the opening or port 44, the particle material is
electrostatically charged by reason of its proximity to the
electrode 18.
The outlet pipe 55 of the injector device 50 has connected thereto
one end of a circular pipe 60, see more particularly FIG. 1, of
which one end 61 extends beyond the frame 11 and which end forms a
spigot coupling end to detachably receive a socket coupling end 62
of a flexible hose 63, see also FIG. 4, which at its other end has
mounted thereon a tubular socket handle 64 of a handle device and
through which a tubular extension 65 or connection part of the hose
63 extends and said pipe 60 and hose 63 form a connecting passage.
At one end of the extension 65, which extends beyond the handle 64,
there is mounted externally thereon an electrostatic connecting
ring or electrode 66 which is connected to a lead 67 which is
mounted on the exterior of the extension 65 and of the hose 63 and
at its other end can be detachably connected by a connection
diagrammatically indicated at 68 to a lead 69 which is mounted on
the exterior of the tube 60 and is connected to the electrostatic
generator 22. Thus the leads 67 and 69 are supported by the hose 63
and tube 60 respectively and can be electrically connected together
and disconnected by simple acts of connecting the hose 63 to the
pipe 60 and disconnecting said hose and pipe respectively.
Secured to the socket handle 64 is a housing 70 to which the socket
handle is earthed at 71 and supported by the housing 70 is a
manually rotatable clamping screw 72 of which the inner end 73
enters the socket handle 64 to clamp onto a feed tube or connection
part 74, see FIG. 5, of a subsidiary discharge head 75 of the
manually supported apparatus part previously referred to, after
said tube 74 has been inserted over the ring 66 and extension tube
65 into the socket handle 64 until the outer end of the tube 74
abuts a stop shoulder 76 in the socket handle and in which position
the electrostatic connecting ring 66 contacts a connecting end of a
lead 78 at the inner end of the tube 74.
The inner end of the feed tube 74 is secured in a cylindrical wall
79 of the subsidiary discharge head 75 which is closed at one end
by an end plate 82 and at its other end provides a subsidiary
discharge head opening 83 across which extends a metal electrode 84
of openwork mesh formation and connected to the lead 78. Spaced a
small distance inwardly from the electrode 84 is a brush 86 which
is in the form of a circular disc and of which the bristles extend
from a backing pad towards the electrode 84 and said brush
constitutes a discharge agitating means for the particle material
and is secured to one end of a spindle 88 adapted to be rotated by
an air-operated motor 90 supported by the end plate 82. The air
motor 90 is connected by an air feed pipe 92 to a pipe union 93,
see FIG. 4, mounted on the housing 70 which also supports a
manually operable air control tap 94 communicating with the union
93 and with a pressure air feed pipe 96 connected to the air
compressor 159 as indicated.
Mounted on the housing 70 is an electric switch 97 by which the
electrostatic generator 22 can be readily connected to and
disconnected from the mains supply and also a further electric
switch 99 by which the electric motor 32 can be switched on and off
and it will be appreciated that the control tap 94 and electric
switches 97 and 99 are all conveniently placed for manual operation
by a person holding the socket handle 64 which is shown for
convenience only as resting on the top of the frame 11. If the air
compressor 159 is electrically driven a further switch, not shown,
may be mounted on the housing to start and stop the compressor.
The feed tube 74 of the subsidiary discharge head 75, see FIG. 5,
enters the cylindrical wall 79 at an end portion thereof remote
from the electrode 84 and disposed between said feed tube and
electrode is a transverse baffle plate 98, which is of
substantially semi-circular formation and extends between the wall
79 and the exterior of the air motor 90 which, in addition to
having an air inlet in communication with the air feed pipe 92,
preferably also has an air exhaust, not shown, externally of the
head 75.
Formed in the cylindrical wall 79 at a diametrically opposite
position to the feed tube 74 is a relief or bleed opening 100
across the entire area of which extends a perforated support grid
102 lined with a porous liner 104 which may be made of expanded
polystyrene.
In order to apply a coating of particle material to a substrate
wall or ceiling, after the feed tube 74 has been inserted into the
socket handle 64 and the clamping screw 72 has been tightened onto
the feed tube and the substrate surface has had a suitable adhesive
applied thereto, the operator grips the socket handle 64 and
suitably orientates the portable subsidiary discharge head 75 so
that the subsidiary discharge head opening 83 thereof, across which
the electrode 84 extends, is directed to said adhesively coated
substrate surface and the two manually operable switches 97 and 99
are operated to charge the electrodes 18 and 84 and to start the
electric motor 32. The air compressor 159 is also started in a
manner dependent upon whether this is an electrically or, for
example, an internal combustion engine driven air compressor and
the control tap 94 is manually opened whereby the air motor 90 is
caused to rotate the agitating brush 86.
The opening or port 44 is manually opened by operation of the slide
46 and particle material in the container 14 is supplied in a
constant regulated manner to said opening or port by the measuring
chambers 42 of the agitating and metering device 35 which is
rotated at a constant selected speed by the electric motor 32 and
which speed is found to be suitable for the particular particle
material being used. Resulting from the action of the injector
device 50, a stream of particle material which has been
electrostatically charged by the electrode 18 is fed through the
pipe 60, hose 63 and extension 65 into the portable subsidiary
discharge head 75 and the material passes past the agitating brush
86 and through the electrode 84 and subsidiary discharge opening 83
and thence onto the adhesively coated substrate surface. Surplus
air passes through the opening 100 and is filtered by the liner 104
so that particle material does not pass through said opening.
Whilst the subsidiary discharge head 75 is satisfactory for coating
the major parts of a wall or ceiling surface, it is not ideally
suitable for coating the surfaces forming an inside corner and for
this purpose a portable subsidiary discharge head 106, illustrated
in FIG. 6, is employed. This subsidiary discharge head 106
comprises a circular feed pipe or connection part 108 which is
adapted to be inserted into the socket handle 64 against the stop
shoulder 76 and is secured by the clamping screw 72. The subsidiary
discharge head 106 is provided at its end opposite the feed tube
108 with a flattened fishtail formation 107 (illustrated in end
elevation in FIG. 9) affording an elongated rectangular discharge
opening 109. It follows, therefore, that the length of the opening
is considerably greater than the width of the opening which is
slightly smaller than the upright external width of the fishtail
formation shown in FIG. 6. The flattened fishtail formation 107 is
capable of being inserted into inside corner formations to apply a
particle material coating to the substrate surface or surfaces to
completely cover said surface or surfaces.
The subsidiary head discharge opening 109 is not provided with an
electrode and it is found that as the particle material is
initially charged by the electrode 18, it is sufficiently recharged
or boosted by the electrostatically charged connecting ring or
electrode 66 through which the particle material passes before
being discharged through the opening 109.
The strength or intensity of the suction effect developed by the
injector device 50 can be varied by altering the width of the gap
50 by adjustment of the outlet pipe 55 relative to the nozzle 51 so
that the rate of flow of the stream of air and particle material
through the outlet pipe 55 can be adjusted to suit requirements.
Furthermore, the supply of particle material to the port 44 and
thus to the injector device 50 is controlled by the power driven
agitating and metering device 35 so that an accurately regulated
supply of particle material is provided for the injector device 50
and thus to the portable subsidiary discharge heads 75 or 106.
Alternatively, when the discharge head 28 is being used and the
opening or port 44 has been closed by the slide 46, the particle
material is fed from the chambers 42 downwardly through the
electrode 18 and main discharge head opening 31 at an accurately
regulated uniform rate dependent partially upon the selected speed
of rotation of the agitating and metering device 35.
Thus, the agitating and metering device 35 is employed when any one
of the three discharge heads 28, 75 and 106 is used and ensures
that an accurately controlled uniform rate of discharge of the
particle material issues from the particular discharge head whereby
a uniform coating of particle materials is applied to the substrate
surface.
The distance of the adjusting or metering device 35 from the
electrode 18 and of the brush 86 from the electrode 84 can be
adjusted in any convenient manner to exercise a measure of control
of discharge of the particle material from the heads 28 and 75
respectively and for this purpose the speed of rotation of said
device 35 and brush 86 can also be adjusted.
Whilst the apparatus illustrated in the drawings is specifically
intended for use with particle material in the form of fibres of
such a length as to enable a pile carpet coating to be applied to a
substrate surface and which fibres may be made of nylon or other
suitable plastics or other material, it should be appreciated that
the apparatus is also suitable for particle materials of other than
fibrous formation. When fibres are employed, however, the effect of
electrostatically charging the fibres is that during their movement
from the appropriate discharge head 28, 75 or 106 they are caused
to assume a parallel orientation and are aligned in the direction
between the discharge head and the substrate surface and their
velocity is such that their ends adjacent said surface penetrate
the settable adhesive coating to a sufficient depth that the fibres
are embedded in the adhesive coating and afford mutual support for
each other and provide an upstanding pile on said substrate
surface.
* * * * *