Note: Descriptions are shown in the official language in which they were submitted.
CA 02578765 2007-02-22
27954-21D
1
APPARATUS FOR FORMING A GUIDE COAT
AND REPLACEMENT PARTS THEREOF
TECHNICAL FIELD
This invention relates to apparatus for forming a guide coat on a
surface, e.g. the surface of a vehicle body which is being repaired
and refinished, and to replacement parts thereof, e. g. re-fills for
such apparatus.
BACKGROUND ART
When a surface such as that of a vehicle body is being refinished,
particularly after repair of accident damage, it is common practice to
apply body fillers and stoppers (a very fine filler) and a series of
layers of primers, stone chip or corrosion protection coatings, paint
coats and sealants etc. which are each rubbed down before application
of the next coat in order to obtain a smooth surface and to assist in
re-working of top paint coats and lacquers. Filling materials are used
to repair indentations, scratches etc. and these are prepared by
sanding, filing and other abrasive techniques to achieve a smooth
surface. This may be done using power assisted equipment or by
hand. A range of abrasive materials may be used such as sand
papers, production papers, wet and dry abrasive papers and sanding
pads. Coarse abrasives are initially used then finer and finer
abrasives until the desired finish is achieved.
To assist in this process it is known to apply a guide coat to the
surface being re-finished. The guide coat is an intermediate coat
applied to one of the re-finishing coats to provide a visual guide to
the progress of such smoothing operations. As the surface of a
coating of, say, primer is eroded by sanding, the guide coat is
removed from the high spots of that coating whereas the guide coat
remains on low spots or other indentations. The operator may
continue the abrading process to smooth out these irregularities and
thus remove the guide coat or it may prove necessary to correct
surface irregularities revealed by further filling or re-working the
surface ( e. g. by panel beating) before the sanding process is
continued. The guide coat thus helps the operator to achieve a
CA 02578765 2007-02-22
27954-21D
2
smooth finish by visually enhancing any irregularities remaining in the
surface during sanding and by indicating the areas which have not yet
been sanded. Such a guide coat may be used at each stage of the
process, i.e. for each coating which requires rubbing down, or as
required by the operator. A guide coat may also be applied to
highlight particular surface irreguiar~.ties or blemishes such as
scratches, pin holes,"orange peel" or dry spray edges.
The guide coat is conventionally formed by a dilute mixture of paint
and thinners, e. g. 1 part paint to 10 parts thinners, sprayed over
the surface being finished. However, this suffers from the
disadvantages that surrounding areas need to be masked, as the
thinners based coating may stain or otherwise damage good paintwork,
and as the thinners is usually a volatile petrochemical, such as a
cellulose solvent, the operator should wear a mask and fume extraction
is required for the area in which the work is carried out. With
increasing legislation designed to protect the environment, severe
restrictions are likely to be imposed on such fume extraction and the
use of such solvent based guide coats may no longer be permitted. In
addition, there are the usual problems associated with the storage of
such flammable liquids.
US4752147 discloses a fluid applicator system comprising a fluid
containing jar, an applicator sponge attached to a lid and a perforated
plate at an adjustable position within the jar for compressing the
sponge and thus regulating the amount of fluid it can absorb. This
prior art does not, however, relate to the formation of a guide coat of
finely divided particulate material.
This invention aims to provide apparatus for forming a guide coat
without the need to use such petrochemical solvents and so avoids the
disadvantages of these materials.
DISCLOSURE OF INVENTION
According to a first aspect of the invention, there is provided guide
coat forming apparatus comprising a first container part within which
material for distributing over a surface as a guide coat is held in a
CA 02578765 2007-02-22
27954-21D
3
substantially loose, finely divided particulate form;
perforated means through which the particulate material can
be sprinkled or shaken; and a second container part for
receiving applicator means on which the particulate material
is to be sprinkled or shaken.
According to a second aspect of the invention,
there is provided guide coat forming apparatus comprising: a
container within which material for distributing over a
surface as a guide coat is held in a substantially loose,
finely divided particulate form, and perforated means
through which the particulate material can be sprinkled or
shaken being mounted at the mouth of the said container.
According to further aspects of the invention
there is provided a first container part housing said
material when supplied for use as a replacement part of
guide coat forming apparatus and material for distributing
over a surface as a guide coat when supplied for use in
recharging guide coat forming apparatus.
According to yet a further aspect of the
invention, there is provided a first container part,
comprising: a first container part having material for
distributing over a vehicle surface as a guide coat in a
substantially loose, finely divided particulate form which
is supplied for use as a replacement part for a guide coat
forming apparatus, the first container part being mutually
engageable with and removably secured together with a second
container part of said guide coat forming apparatus.
Other features of the invention will become
apparent from the following description and from the
subsidiary claims of the specification.
CA 02578765 2007-02-22
27954-21D
4
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be further described,
merely by way of example, with reference to the accompanying
drawings in which:
Figure 1 is a perspective, exploded view of a
first embodiment of the apparatus according to the
invention;
Figure 2 is a perspective view of a second
embodiment of apparatus according to the invention; and
Figure 3 is a perspective view of a third
embodiment of apparatus according to the invention.
CA 02578765 2007-02-22
27954-21D
BEST MODE OF CARRYING OUT THE INVENTION
Figure 1 shows apparatus comprising a container in the form of a
plastics or metal can of a size suitable for holding in the hand, e. g.
around 10cm in diameter and 10cm tall. The can is formed in two
parts, a lower reservoir part 1A and an upper cylindrical part 1B.
The two parts may be secured together by a push fit, screw threads
or other suitable attachment means. A dry powder 2, e. g. a black,
non-toxic, water-based powder paint, is held in the reservoir part 1A
and a drying agent, for instance rice 3, is preferably mixed with the
powder 2 to help keep it dry. A perforated plastics or metal plate 4
is fitted to the upper end of the reservoir part 1A. The perforations
5 in the plate 4 are large enough to allow the powder 2 to pass
therethrough but small enough to prevent the passage of the drying
agent 3 through the plate 4. The perforations would typically have
dimensions of around 1-2mm. The drying agent may also be contained
in a sachet or other enclosure as well known in other fields. The
perforations may be of any suitable shape and arranged in any
suitable pattern. The plate 4 may be removable from the reservoir
part 1A or may be permanently secured thereto.
The container 1 is provided with closure means in the form of a lid 6
which has applicator means in the form of a synthetic sponge 7
attached to the underside thereof. The applicator sponge 7 is sized
so that it fits within the top of the upper container part 1B when the
lfd 6 is fitted onto the container part 1B.
In use, the container is shaken or inverted with the lid 6 in place so
that powdered paint 2 passes through the plate 4 onto the sponge 7.
The lid 6 can then be removed and held in the hand to apply the
powdered paint adhering to or impregnated in the sponge 7 to the
surface on which the guide coat is to be formed. The powder is then
distributed over the surface by simply wiping the sponge 7 over the
surface to leave a thin coating of dry powder thereon which acts as a
guide coat in a similar manner to the conventional form of guide coat
described above.
CA 02578765 2007-02-22
27954-21D
6
It has been found that the powder remains on relatively rough
surfaces such as those of a car body panel being rubbed down (even
when it has been rubbed down by a very fine abrasive sheet, e. g.
P1200 paper) even whilst the surface is vertical or downward facing
but does not remain on or can easily be wiped or blown off a
relatively smooth surface such as that of the gloss paint on a car body
panel. The powder is removed by subsequent rubbing down
techniques, using abrasive blocks, wet and dry sand paper, etc. as
described above. The majority of the powder is removed in this way
but it has been found that any small amounts of powder remaining
after rubbing down can be left in place and are not detrimental to the
application of further filler, primers etc. Any powder falling on
surrounding paintwork can be simply wiped off with a clean rag,
brushed or blown off or removed by washing the surface with water or
other suitable solvent.
The perforated plate 4 is preferably provided in the container 1 to
help control the quantity of powder applied to the sponge 7 when the
container 1 is shaken or inverted. However, it is possible to omit the
plate 4 and if excess powder falls onto the sponge 7 this can be
shaken off before the sponge 7 is used to apply powder to a surface.
When the reservoir part 1A is charged with powder 2, sticky tape or a
sticky label or some other form of seal (not shown) may be provided
over the perforations 5 to prevent powder passing through the plate 4
when the product is being transported or handled before use. The
seal is then removed before the apparatus is first used.
The reservoir part 1A may also be supplied on its own as a
replacement part for installation in the apparatus when the initial
reservoir part 1A has been emptied. Such a"re-fill" may be provided
with the perforated plate 4 with the perforations sealed as described
above or may be supplied without the plate 4 in which case the
container needs to be sealed, e. g. in the same manner as a coffee jar,
or sealed by its packaging, e.g. of shrink-wrap plastics material.
CA 02578765 2007-02-22
27954-21D
7
The cylindrical part 1B of the container serves to interconnect the
reservoir part 1A and the lid 6 and also to provide a space above the
plate 4 in which the applicator sponge 7 fits when the lid 6 is fitted to
the container.
The reservoir part 1A and the cylindrical part 1B may each be
provided with mutually engaging locating means such that only a
reservoir part 1A having the appropriate locating means can be fitted
to the cylindrical part 1B.
The applicator sponge 7 preferably comprises a compressible medium
density synthetic foam material which is capable of absorbing sufficient
powder but which is sufficiently firm to enable the powder to be
applied to a surface by wiping the sponge 7 over the surface. One
form of material which has been found to be suitable is a foam sponge
supplied by Motofax Ltd. under the designation Foam Mator Ester 280
Blue. The sponge 7 would typically have a diameter of around 8cm
and project around 4cm from the lid 6. The sponge 7 may be simply
affixed to the lid 6 by means of an adhesive. Alternatively, the
sponge 7 may be removably attached to the lid 6 so it can be replaced
if it becomes worn.
Other forms of app3icator means may be used, e.g. a synthetic foam,
an absorbent cloth or wad of material (such as natural or man-made
lambswool) or a soft brush, the main requirement being that the
applicator means is capable of absorbing or becoming impregnated with
a sufficient quantity of -powder which can then be distributed over a
surface by wiping the applicator means over the surface.
The lid 6 is preferably provided with ribs or other gripping means
around its periphery so that it can be held comfortably in the hand
when the sponge 7 is used to apply the powder to a surface.
Alternatively, or additionally, the lid may be provided with a strap or
band which in use passes around the back of the operator's hand and
helps hold the lid and applicator in place in the operator's hand. In
another arrangement, a handle, e. g. in the form of a paint brush
handle, may be attached to the applicator.
CA 02578765 2007-02-22
27954-21D
8
As mentioned above, the lid 6 and sponge 7 may be separate parts
which are secured together. It would also be possible for the
applicator means and the closure means to be formed by one item, e. g.
by a relatively firm sponge which is shaped to be a push fit within
the open end of the container 1 and thus act as closure means.
In another arrangement, the closure means and applicator means may
be separate items, for example the closure means may comprise a
simple lid and the applicator means comprise a separate sponge which
can be stored outside the container or, preferably, within the
container.
Any finely divided particulate material or medium may be used to form
the guide coat as long as it can be easily distributed over the surface
to be smoothed and has the tendency to remain on and thus highlight
irregularities on the surface. A powder such as a non-toxic, water
soluble black powder paint obtained from the Early Learning Centre
(South Marston, Swindon SN3 4TJ, UK) has been found to be suitable.
The particulate material may be of any appropriate colour depending
on the application. A black guide coat is usually used in the repair
of car body panels as this shows up welt on light coloured fi.ller
materials and on grey primers and undercoats. The material used
should preferably be non-staining to paint finishes such as those used
on vehicle bodywork. Powder paints for use by children have to meet
strict health and safety requirements and are thus believed to be made
of natural or inert materials which are unlikely to cause harm if
ingested. Materials used in such paints include dried albumen and
chalk. Black paints include carbon black and other colours are
obtained by the use of natural colouring agents as used in the food
industry.
The lid 6 is preferably a tight press-fit onto the container 1 so as to
prevent leakage of powder when the lid 6 is in place. Alternatively, a
screw-fitting or snap-fit lid may be used.
CA 02578765 2007-02-22
27954-21D
9
Figure 2 illustrates apparatus comprising just a powder reservoir 8
and an applicator sponge 9. The powder reservoir comprises a
container 8A for holding powder and a perforated plate 8B provided at
the mouth of the container 8A. The perforated plate 8B may be
removable from the container 8A or may be affixed thereto. It will be
appreciated that the powder reservoir 8 and applicator sponge 9 may
be supplied together or separately as replacement parts in a similar
manner to the corresponding parts described above in relation to
Figure 1.
Figure 3 shows another form of the apparatus. This comprises a two-
part container 1, the lower part 1A of which holds the powder 2 and
the upper part 1B of which carries the perforated plate 4. The two
parts 1A and 1B are arranged to fit together e. g. by means of a
push-fit, screw threads or other suitable attachment means. The plate
4 is preferably mounted at the upper end of the upper part 1B or it
may be positioned within the upper part 1B.
The applicator sponge shown in Figure 3 has a cylindrical portion 7A
for holding in the hand and a shaped portion 7B for applying the
powder 2 to a surface. Again, the applicator sponge may be provided
separately as a replacement part.
Additional powder can be supplied either in a container which replaces
the lower part 1A described above or both the lower part 1A and the
upper part 1B may be supplied together as a replacement part. If the
plate 4 is removable from the upper part 1B, it may also be supplied
separately. Otherwise, if a new plate 4 is required it may be supplied
installed in a replacement upper part 1B.
In each of the embodiments described, it will be appreciated that it
would also be possible to provide additional powder in a sachet, bag
or some other enclosure for re-charging the powder reservoir once
this has been emptied. This would obviously be most easily done in
those embodiments in which the perforated plate or a component
housing the perforated plate 4 is removable from the container to be
re-charged with powder.
CA 02578765 2007-02-22
27954-21D
It will be appreciated that the apparatus described above, although of
simple construction, provide: an easy and effective way of applying a
guide coat to a surface. The method of forming a guide coat
described also has many advantages over conventional methods:
masking of surrounding paint work is not required, it uses more
environmentally safe materials which are not combustible or volatile, no
special storage conditions are required and the powder has a long
shelf-life, and, if a dry powder is used, no drying time is required
once the guide coat has been applied.
The apparatus described above comprises various components: a lid
and sponge of the type shown in Figure 1, upper and lower parts of a
container of the type shown in Figure 1, applicator sponges of the
types shown in Figures 2 and 3, a powder reservoir as shown in
Figure 2, a removable perforated plate 4, and an upper container part
1B and a lower container part 1A as shown in Figure 3. It will be
appreciated that not only may these various parts be supplied
separately as replacement parts of "re-fills", but the parts may also
be combined in other combinations besides those illustrated in the
drawings. As described above, the interconnecting parts are
preferably provided with mutually engageable locating means such that
only parts having the appropriate locating means can be securely
fitted together.
INDUSTRIAL APPLICABILITY
The apparatus and method described can be used in a v,ride variety of
applications such as the rubbing down of layers of filler or primer or
undercoats of paint used in the repair of a car body panel as
described above including both dry flatting processes and wet and dry
processes. It may also be used for forming a guide coat in the
rubbing down or machining of other surfaces whether of metal, wood,
glass or other material.
