SYSTEM FOR CHANGING COATING MATERIAL IN A DISPENSER

SYSTEME SERVANT A CHANGER LE MATERIAU DE RECOUVREMENT DANS UN DISTRIBUTEUR

English Abstract

A system for changing the coating material type
supplied to a dispenser includes a manifold having a passageway
through which the coating material flows during its selection.
A number of other passageways intersect the first passageway.
Supply valves mounted to the manifold control the flow of coating
material through a selected one of the intersecting passageways
into the first passageway. The mechanism fox actuating the flow
control is controllable by an air signal positioning the control
member and thereby controlling the supply of coating material to
the first passageway. The manifold and valve bodies include
second passageways that are coupled to a source of air under
superatmospheric pressure. A valve controls the flow of air
through the second passageway from the compressed air source to
the interior of each valve body. By incorporating the second
passageways into the manifold and valve bodies themselves, the
distance the air signal must pass from the electrically operated
valve to the control mechanism is minimized to advantage.

Claims

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What is claimed is:
1. A coating material type change system for
changing the type of coating material being supplied to a
dispensing device from one type to another, the system
including a manifold having a main coating material
passageway through which a selected type of coating
material flows during its selection as the type to be
supplied to the dispensing device, a plurality of secondary
coating material passageways intersecting the main
passageway, an equal plurality of coating material supply
valves mounted to the manifold, each coating material
supply valve having a body and a member movable in an
interior portion of the valve body for controlling the flow
of the coating material to be supplied by that coating
material supply valve through a respective secondary
coating material passageway to the main coating material
passageway and a mechanism for actuating the member, the
mechanism being controllable by a control fluid selectively
to control the position of the member and thus the supply
of the coating material to the main coating material
passageway, the manifold and valve bodies including control
fluid passageways and means for coupling the control fluid
passageways to a source of control fluid at
superatmospheric pressure, a valve seat for coupling each
control fluid passageway to the interior portion of a
respective valve body, and an equal plurality of
electrically operated valves for controlling the flow of
control fluid through the respective control fluid
passageways from the source of control fluid to the

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interior portions of respective valve bodies to minimize
the distance the control fluid must travel from a
respective electrically operated valve to the interior
portion of a respective valve body.
2. The system of claim 1 wherein the electrically
operated valves are intrinsically safe electrically
operated valves.
3. The system of claim 1 wherein the different
coating material types are different coating material
colors.
4. The system of claim 2 wherein the different
coating material types are different coating material
colors.

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5. A coating material type change system for
changing the type of coating material being supplied to a
dispensing device from one type to another, the system
including a manifold having a main coating material passageway
through which a selected type of coating material flows during
its selection as the type to be supplied to the dispensing
device, a plurality of secondary coating material passageways
intersecting the main passageway, an equal plurality of coating
material supply valves mounted to the manifold, each coating
material supply valve having a body and a member movable in an
interior portion of the valve body for controlling the flow of
the coating material to be supplied by that coating material
supply valve through a respective secondary coating material
passageway to the main coating material passageway and a
mechanism for actuating the member, the mechanism being
controlled by a control fluid selectively to control the
position of the member and thus the supply of the coating
material to the main coating material passageway, the manifold
including a first control fluid passageway coupled to a source
of control fluid at superatmospheric pressure, each supply
valve body including a second control fluid passageway in fluid
communication with the first fluid passageway, each coating
material supply valve further including a closure cap having
a third control fluid passageway in fluid communication with
the second control fluid passageway in the supply valve body
and a fourth control fluid passageway in fluid communication
with said interior portion of the supply

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valve body, each coating material supply valve having an
electrically operated pilot valve directly coupled to the
supply valve closure cap, each pilot valve including a
valve seat for controllably coupling each third control
fluid passageway to each fourth control fluid passageway to
enable control fluid to enter the interior portion of a
respective supply valve body to minimize the distance the
control fluid must travel from a respective electrically
operated pilot valve to the interior portion of a
respectively valve body.
6. The system of claim 5, wherein the first control
fluid passageway communicates with each second control
fluid passageway via an annular groove formed in each
coating material supply valve body.
7. The system of claim 6, wherein each second
control fluid passageway communicates with its
corresponding third control fluid passageway via an annular
groove formed in one of the coating material supply valve
body and its corresponding closure cap.

Description

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SYSTEM FOR CHANGING COATING MATERIAL IN A DISPENSER
This invention relates to a manifold for distribution
of coatings from various different coating material sources to
a coating dispensing device.
The technology of coating materials distribution is
well documented. There are, for example, the systems described
in the following listed U.S. Patents: 4,311,724; 4,348,425:
4,422,576: and 4,592,305.
Intrinsically safe technology in coating material
distribution systems is discussed in some detail in U. S . Patent
4,957,060 and references cited there, notably U.S. Patent
4,278,046 and Ernst Greg, "Intrinsic Safety -- An Alternative
to Explosion-Proof", Measurements and Control, Apr. , 1987, pp. 148
151.
In systems of the type described in U.S. Patent
5,146,950 and an earlier device of the applicant, pneumatic
signals are coupled to the color valves on the color change
manifold from a remote source. Such systems rely on a
pneumatic signal for the final feed from the color valve
controller to the individual color valves mounted on the color
change manifold. The applicant's said earlier system makes an
effort to reduce to a minimum the pneumatic signal "lag"
present in prior art systems. However, even further reduction
in pneumatic signal lag is possible.
According to the invention, a coating material type
change system changes the type of coating material being
supplied to a dispensing device from one type to

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another. The system includes a manifold having a first
passageway through which a selected type of coating
material flows during its selection as the type to be
supplied to the dispensing device. The manifold further
provides a plurality of coating material passageways
intersecting the first passageway. An equal plurality of
coating material supply valves is mounted to the
manifold. Each coating material supply valve has a body
and a member movable in the interior of the valve body
for controlling the flow of the coating material to be
supplied by that coating material supply valve through a
respective coating material passageway to the first
passageway and a mechanism for actuating the member. The
mechanism is controllable by an air signal selectively to
control the position of the member and thus the supply of
the coating material to the first passageway. The
manifold and valve bodies include second passageways and
means for coupling the second passageways to a source of
air under superatmospheric pressure. A valve seat
couples each second passageway to the interior of a
respective valve body. An electrically operated valve
controls the flow of air through the second passageway
from the source of compressed air to the interior of each
valve body. Incorporating the second passageways into
the manifold and valve bodies themselves minimizes the
distance the air signal must pass from the intrinsically
safe electrically operated valve to the mechanism.
According to an illustrative embodiment, the
electrically operated valves are intrinsically safe
electrically operated valves.
According to an illustrative embodiment, the
different coating material types are different coating
material colors.
The invention may best be understood by
referring to the following description and accompanying

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drawings which illustrate the invention: In the
drawings:
Fig. 1 illustrates fragmentarily and highly
diagrammatically an end elevation of a spray booth
incorporating a system according to the present
invention; and,
Fig. 2 illustrates somewhat less
diagrammatically a fragmentary sectional view of a detail
of the system illustrated in Fig. 1, taken generally
along section lines 2-2 thereof.
Turning now to Fig. 1, a spray booth 10 is
illustrated for the application of fluent coatings of
various types, e.g., colors, to successive automobile
bodies 12 as the bodies 12 are conveyed through the booth
10. The coatings are subsequently cured or otherwise
fixed on the bodies 12 by other well known means, such as
IR ovens, which will not be further discussed in any
detail. Booth 10 is ventilated 14 and the atmosphere
withdrawn from the booth 10 is customarily rigorously
scrubbed or otherwise treated to remove oversprayed
coating material and the like.
The fluent coatings are applied by dispensers
16 which may be, for example, guns of the type described
in U.S. Patents 3,169,882 or 3,169,883, or rotary
atomizer of the type described in U.S. Patent 4,148,932.
The fluent coatings illustratively are supplied
from a so-called "paint kitchen" containing, for example,
several sources of colors to color valves 18 mounted on a
color change manifold 20. The color valves 18 and color
change manifold 20 illustratively are generally of the
type illustrated and described in U.S. Patent 5,146,950.
The various colors of coating materials continuously
circulate from the paint kitchen through the valves 18
and back to the paint kitchen. When a selected one of
the valves 18 is opened by an air signal provided to it,

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some portion of the circulating coating material is
shunted through the open valve 18, into the manifold 20
and then from the manifold 20 to the dispensing device
16, from which it is dispensed onto the automobile body
12.
The air signals to open the various color
valves 18 are provided from a common "factory air"
compressed air source 22 through air passageways 24, 26,
28, 30 (Fig. 2) provided in the manifold body 32 itself,
the various color valves' respective bodies 34
themselves, and the color valves' closure caps 36. The
air passageways 24 are coupled by appropriate couplings
38 to compressed air source 22. Caps 36 illustratively
are only about 1 cm or so in thickness. This
construction reduces to a minimum the lag between the
generation of the "open valve" air signal and the arrival
of that signal at the color valve 18 to be controlled.
The arrival of the coating material at the dispenser 16
is thus capable of much tighter control than with prior
art systems of the types illustrated in U.S. Patents
4,957,060 and 4,278,046.
Identical valves 40 to color valves 18 are
provided for the other services, such as low and high
pressure compressed air and solvent, to the color change
manifold 20. An intrinsically safe electric valve 42 is
provided on each of the air valve caps 36 and controls
air flow through its respective air valve cap 36 from the
compressed air source 22 to its respective color valve 18
or service valve 40. Electric valves 42 illustratively
are 15.5 VDC, .65 watt solenoid valves, such as Clippard
Instrument Laboratories, Inc., model EI-3M Minimatics"'
valves. The valve bodies 34 and closure caps 36 are
provided with annular grooves 44 and 46, respectively, so
that alignment of the passageways 24, 26 and 26, 28 is
not critical to the supply of compressed air to the

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interiors of valve bodies 34 when their respective
electric valves 42 are actuated. Additionally, suitable
sealing rings 48, 50, 52, 54, 56 are provided at
appropriate locations in the manifold body 32, caps 36
and electric valves 42.
The 15.5 VDC signals which control the various
color and service valves 18, 40 are provided through
current limiting barriers of conventional construction
and operation which minimize the flow into the booth 10
of electrical energy under any foreseeable failure mode
of the electrical system which supplies the electric
valves 42. These 15.5 VDC signals can be generated and
distributed in any suitable manner, such as from a
computer which controls the coating operation and
sequence of colors, solvents, compressed air, etc. to be
dispensed, working through a suitable interface.
Mounting of the electric valves 42 directly to
the color and service valves 18, 40 and supply of the
factory compressed air 22 to the manifold body 32 and
through the wall of each valve body 34 and cap 36
directly to the respective valve 18, 40 reduces the
distance across which the pneumatic signals which control
the valves 18, 40 must travel to a minimum. That
distance, which can best be appreciated by referring to
Fig. 2, is basically the thickness of the color valve's
closure cap 36. Additionally, it reduces substantially
the number of compressed air lines which must be supplied
within the coating booth 10.

Representative Drawing