[0001] THIS INVENTION relates to a method of and apparatus for, supplying paint to a site
of application thereof, such as a method of, and apparatus for supplying paint for
use on road marking vehicles. More particularly the invention relates to a method
of supplying paint to a site of application thereof, the paint having a pigment component
and at least one other carrier component, in which components of the paint are stored
separately in containers.
[0002] Prior proposed road marking vehicles usually have two separate storage tanks for
paint, one for yellow paint and the other for white paint, since these two colours
are almost universally the only colours used in road marking applications.
[0003] The tanks also each have their own pumping system and sometimes each have their own
heating system where the tanks are to contain paint that must be kept hot.
[0004] In most operations only paint of one colour is used, thus leaving paint of the other
colour in the appropriate storage tank unused. Where both colour paints are used simultaneously,
almost invariably one of the tanks runs empty before the other. This results in a
time consuming stop for refiling of the empty tank. Also, the cleaning of any tank
to take paint of another colour is very time consuming.
[0005] While it is desirable to increase the capacity of the tanks to obviate these problems,
it has been found to be impractical to accommodate very large tanks on a road marking
vehicle.
[0006] In other applications where paint is used, for example in spray painting, similar
problems exist. Paint of a particilar colour shade may be mixed for use in a spraying
operation, and if not completely used up is usually wasted.
[0007] The separation of ingredients of paint of one colour for use in road marking is known.
This is done with a view to improving the mechanical methods of, and apparatus for,
the application of paint to a surface.
[0008] In French Patent Specification No. 1,492,468, a system is described in which ingredients
of paint are stored separately, the ingredients being such that on mixing the resultant
paint commences to harden. The components are mixed to form a paint immediately prior
to the application of the paint. The characteristics of the final paint layer are
determined by, inter alia, the feeding of the ingredients in a particular predetermined
ratio, and the speed of ingredient feed relative to the speed of a vehicle applying
the paint to a road marking surface.
[0009] United States Patent Specification No. 3,083,913, describes an apparatus for spraying
paint from a mobile vehicle. The apparatus includes pumps which ensure that at the
commencement of operation a first ingredient of a paint is always pumped to a spray
apparatus before a second ingredient thereof.
[0010] These systems do not provide a solution to the problem of wastage of excess paint
as a result of its colour not being further required. Neither are they intended to
solve the problem of uneven usage of different colours of paint for example on a road
marking vehicle.
[0011] The present invention seeks to reduce or obviate these problems and the present invention
is characterised in that at least the pigment component of a paint to be used is stored
in a separate container and the paint carrier component is stored in a larger container
the pigment being mixed together with the correct proportion of paint carrier component
at or immediately adjacent the site of application just prior to paint application.
[0012] The advantages of the claimed invention lie in that the colouring of the paint is
achieved at or immediately adjacent the site of application thereof, and then only
during actual application. Thus there is no wastage of the ingredients of the final
paint mixture as a result of the above described problems.
[0013] It is to be understood that reference to "paint" in this Specification includes all
colouring matter which may be applied to a surface for the purpose of colouring it,
and which comprises a pigment and at least one other component. It includes therefore,
for example, inks, colouring matter which requires binding, thermoplastic components,
colouring mixtures having two components epoxies, and the like. Thus the paint may
include a pigment, a carrier, and a binder or may include solvents or the paint may
be a pigment and two component resin paint system. The paint may be heated prior to
application.
[0014] A method in accordance with the invention enables a plurality of paints to be used,
i.e. three or more colours, in which case at least the pigment component of each paint
colour is stored in a separate respective container at or adjacent the site of application,
and the paint carrier comprising a mixture of paint components common to all the paints
is stored in a larger container, Thus a desired pigment, and possibly other components,
may be mixed with the correct proportion of paint carrier to form paint just prior
to application of the paint.
[0015] The said containers may be located on a mobile vehicle, and preferably on such a
vehicle which is used in the road marking industry.
[0016] The invention also provides apparatus utilising the above method said apparatus comprising
a number of containers each having an inlet and an outlet means, the outlet means
of each container being operatively connected to a separate respective paint component
metering pump and a container large relative to the aforementioned containers, having
an inlet and outlet means, the outlet means being operatively connected to each paint
component metering pump.
[0017] Preferably the outlet of at least one pump has a homogenizing unit operatively connected
thereto for the blending of a paint being pumped from an outlet in use.
[0018] A preferred embodiment of the invention is descri
- bed below by way of example only with reference to the accompanying drawing which
is a diagrammatic representation of an apparatus for utilising a method according
to the invention.
[0019] Referring to the drawing a relatively large container 1, has an inlet 2, and an outlet
3, the outlet being connected in parallel to two component metering pumps 4 and 5.
[0020] Two further containers 6 and 7, each smaller in size than the container 1 are provided
each having an inlet means 8 and an outlet means 9. The outlet of container 7 is connected
to pump 4 and the outlet of container 6 to pump 5. Each pump has an outlet 10 which
is connected separately to a respective homogenising unit 11. Each unit 11 has an
outlet 12 which is connected to paint spraying apparatus (not shown). A heating unit
(not shown) may be provided to heat the paint prior to application thereof.
[0021] All the connections are made with suitable tubing, and the pumps are of a type which
are readily available on the market. The apparatus is mounted on a road marking vehicle
or the like.
[0022] The larger container 1 is filled via the inlet means with paint carrier comprising
all the components which are common to yellow and white road marking paint. This carrier
usually includes such components as resin, fillers and solvent.
[0023] One of the smaller containers 6 or 7 is filled with yellow paint pigment, usually
yellow chrome or a mixture of yellow chrome and Titanium dioxide. Small quantities
of one or a combination of two or more paint carrier components may be included with
the paint pigment in the correct proportion.
[0024] The other smaller container is filled with white paint pigment, usually Titanium
dioxide. Here too, small quantities of one or a combination of two or more paint carrier
components may be included with the paint pigment in the correct proportion.
[0025] However, other suitable substances which are not normally paint carrier components
may be mixed with the pigment to obtain desired results, for example to obtain a desired
viscosity of the pigment mixture.
[0026] In use, the colours may be used singly or simultaneously. Each metering pump, when
actuated, will pump the correct proportions of pigment and paint carrier to the homogenising
unit and thence to the respective apparatus which applies the paint to a road surface.
[0027] There will normally be sufficient turbulence in the pumps to obtain blending of pigment
with paint carrier but if maximum blending is required, the homogenising units may
be included.
[0028] Since the paint carrier usually comprises about 85% by weight of the final paint,
the invention provides an effective means of utilising storage space and supplying
paint for example on a road marking vehicle.
[0029] There is less dange of running out of one colour paint, say yellow, before the other
colour paint is used up, and filling the smaller containers with pigment or pigment
mixture will be less time consuming than filling a large container with one colour
paint. Cleaning of the containers is also simplified.
[0030] Clearly, many variations of the above embodiment are possible without departing from
the scope of the invention. For example, the invention is not restricted to two small
containers or two colours, since more small containers could be provided nor to colours
of yellow and white, since other colours could be used.
[0031] Neither is the invention restricted to use in the road marking industry, or to use
on a mobile vehicle. The invention is equally applicable for example in the spray
painting of metals or metal sheeting such as is used in steel furniture, or in the
motor car industry.
1. A method of supplying paint to a site of application thereof, the paint having
a pigment component and at least one other carrier component, in which components
of the paint are stored separately in containers, characterised in that at least the
pigment component of a.paint to be used is stored in a separate container (6,7) and
the paint carrier component is stored in a larger container (1) being mixed together
with the correct proportion of paint carrier component at or immediately adjacent
the site of application just prior to paint application.
2. A method as claimed in claim 1 further characterised in that a plurality of paints
are to be used, and at least the pigment component of each paint is stored in a respective
separate container (6,7), and the paint carrier, comprising a mixture of paint components
common to all the paints, is stored in the said larger container (1).
3. A method as claimed in claim 1 or 2 further characterised in that the containers
(1,6,7) are mounted on a mobile vehicle.
4. A method as claimed in claim 3 further characterised in that the vehicle is used
to apply markings to surfaces which are to be traversed by vehicles.
5. A method according to any one of the preceding claims characterised in that the
container or containers (6,7) storing pigment are located at or immediately adjacent
said site.
6. A method according to any one of the preceding claims characterised in that said
pigment has other paint components mixed therewith.
7. A method as claimed in any one of the preceding claims further characterised in
that the paint includes a pigment, a carrier and a binder.
8. A method as claimed in any one of claims 1 to 6 further characterised in that the
paint includes solvents.
9. A method as claimed in any one of claims 1 to 6 further characterised in that the
paint is a pigment and two component resin paint system.
10. A method as claimed in any one of the preceding claims further characterised in
that the paint is heated prior to application.
11. An apparatus for utilising the method claimed in any one of the preceding claims
characterised in that said apparatus comprises a number of containers (6,7) each having
an inlet (8,8) and an outlet means (9,9), the outlet means (9,9) of each container
(6,7) being operatively connected to a separate respective paint component metering
pump (4,5) and a container (1) large relative to the aforementioned containers (6,7),
having an inlet (2) and outlet means (3), the outlet means (3) being operatively connected
to each paint component metering pump (4,5).
12. An apparatus as claimed in claim 11 in which the outlet (10,10) of at least one
pump (4,5) has a homogenising unit (11,11) operatively connected thereto for the blending
of a paint being pumped from an outlet in use.
13. An apparatus as claimed in claim 11 or 12 characterised in that a heating unit
is provided to heat the paint prior to application.
14. An apparatus as claimed in claim 11,12.or 13 characterised in that spray painting
apparatus is connected to apply paint in use.
15. A road marking vehicle characterised in that it is fitted with apparatus according
to claim 11,12,13, 14 or 15.