Note: Descriptions are shown in the official language in which they were submitted.
~ )39~5
This invention relates to the dispensing of coating
materials and is particularly concerned with improvemen~s in
a dispenser for spraying, pouring, or frothing coating
materials.
Dispensing apparatus has been provided here~ofore
for applying a variety of coating materials including various
plastics which are comprised of relatively rapidly reacting
chemical components. Conventional equipment such as the
ordinary paint spray gun is not suitable for the application
of plastic coatings having chemical components which react
rapidly when mixed. While individual components are generally
stable, when they are mixed in proper proportions they react
quickly to form the completed product and take at least a firm
; set or commence to solidify. Consequently, provision must be
made for mixing the components in the proper proportions and
immediately dispensing the mixture. Efforts ha~e been made to
modify conventional paint spraying guns for dispensing plastic
~` materials of this type. Generally, this has involved pro-
viding a mixing chamber within the gun and feeding the ingred-
ients through separate supply lines into the mixing chamber in
proper proportions so as to produce the desired coating. Much
of the apparatus heretofore developed for this purpose has not
been satisfactory, generally because adequate provision is not
made for ~eeping the apparatus clean so that the control
valves and passageways for the ingredients are not clogged
and jammed ~y the plastic components becoming set in the same
and rendering the apparatus inoperative. One apparatus
previously developed and disclosed in my patent ~o. 3,504,855,
granted April 7, 1970, has proven highly efficient in use.
-1-
~3~49S
However, experience with this and other apparatus of this
general character has indicated the desirability of providing
a more simplified gun construction which will provide the
desired operation with satisfactory efficiency and which may
be produced at a lower cost.
It is, therefore, a general object of the invention
to provide an apparatus for dispensing coating materials, by
spraying, pouring or frothing the material, which is of
relatively simple construction and which has adequate provision
for maintaining the materials being dispensed at tha proper
temperakure, for cleaning the control valves and passageways
so that the apparatus may be kept in condition for operation
at all times, and which is sufficiently economical to manu-
facture so as to compete with more complicated apparatus.
It is a more specific object of the invention to
provide a dispenser for coating materials, which includes an
improved valve arrangement of relativel~ simple construction
- for controlling the flow of the separate elements through the
gun so that the valve structures may be kept free of materials
which will clog the same and so that they may be readily
washed with a solvent, without dismantling the gun, and thereby
kept in operative condition.
Another object of the invention is to provide a dis-
penser for coating materials having valve structures for
controlling the flow of the materials from the supply lines
into a mixing chamber, which valve structures are mounted so
that they may be readily removed for cleaning and repairing.
The invention as claimed herein is a device for
mixing and dispensing coating material which includes a body
--2--
~L~39~9~
member having a mixing chamber therein, a discharge nozzle
leading therefrom, and laterally spaced parallel bores extending
therethrough with passageways leading from an intermediate
portion of each bore to the mixing chamber, a flow control
valve in the ~orward end of each bore, an adjustably mounted
flow selector valve in each bore aligned with the flow control
valve, a trigger member having a connection with each of the
flow control valves which is operative in one position to
open said valves so as to allow passage of coating material
:~ 10 through the valves and into the passageways to said mixing
chamber, the trigger member being operative in another position
to close said flow control valves, each selector valve having
an infeed passageway to which an inner supply conduit is
attached and a co-operating passageway for return flow of
material to which an outer conduit is attached, the outer conduit
enclosing the inner conduit, each flow selector valve being
disposed in its bore with the innsr end spaced from the irmer
end of the associated flow control valve so as to leave a
chamber between the valves t each selector valve being adjust-
able between a position to connect the infeed passageway withsaid chamber and a position to close the connection with said
chamber and to connect the infeed passageway with the return
passageway and each flow control valve being disposed in its
respective bore so that when in an open position material will
flow from said chamber through said control valve.
The said ~low selector valves may have paralle~
axially extending, infeed and return passageways, with generally
radially extending outlets at the innermost end, the innermost
end being rotatably mounted in a sleeve member fixed in the
--3--
3~ S
bore, which sleeve member has axial and circumferential
slots arranged to connect the passageways in one rotatable
position of the valve through the chamber between the valves
and in another rotatable position to close off the connection
through said chamber and to connect the infeed and return
passageways.
The said control valves may be mounted in said
: bores for removal in an axial direction and normally locked
in said bores by a locking pin removably positioned in a cross
bore spanning the valve bores with portions engagable in a
co-operating cross groove in each of said val~es.
The said trigger member may have a connection with
the control valves enabling it to be released therefrom and
said connection to be disabled so as to release said valves
from said bores.
The said body member may have a passageway for
connection to a solvent suppl~ line which passageway connects
with each of said flow control valves for passage of solvent
through said valves into the mixing chamber in one position
of the valves and a manually operated solvent valve may be
disposed in said passageway enabling the flow of solvent to
said control valves to be cut off.
The said flow control valves may each have an
axially movable piston member located relative to the
associated flow selector valve so that in one position the
flow control valve and the flow selector valve are open and
material to be mixed flows through both valves to the mixing
chamber while in another position both valves are closed to
cut off the flow of the material.
- ~L039~5
These and other objects and advantages of the
inven~ion will be apparent from a consideration of the
spray gun type dispenser which is shown by way of illustra-.
tion in the accompanying drawings wherein:
: Figure 1 is a side elevation showing a spray gun
which incorporates the principal features of the invention;
Figure 2 is an elevation of the front or trigger
side of the spray gun of Figure l;
Figure 3 is a rear elevation showing the side of the
spray gun opposite the trigger;
Figure 4 is a vertical section taken on the line
- ~-4 of Figure 2;
Figure 5 is a sectional view taken on the line 5-5
of Figure ~;
Figure 6 is a sectional view taken on the line 6-6
of Figure 4;
Figure 7 is a sectional view taken on the line 7-7
of Figure 4;
Figure 8 is a fragmentary sectional view taken on
the line 8-8 of Figure 4, to an enlarged scale, showing the
one selector valve in an DON'I position; and
Figure 9 is a fragmentary sectional view taken on
the same line as Figure 8 but showing the selector valve in
"OFF" position.
Referring to the drawings, there is illustrated a
spray gun type dispenser which is particularly adapted for the
dispensing of a coating material, such as a foam plastic,
which may be, for example, constituted by an isocyanate resin
and a polyol resin with an appropriate solvent and with air
--5--
103~495
pressure employed as a propellant. As illustrated, the gun
is designed for a spraying application. With slight adjust-
ment or modification it may be used for pouring or frothing
the foam material.
The illustrated spray gun comprises a body section
or portion of generally circular cross section constituting a
head 10 and a handle member 11, respectively. The handle 11
is secured at the top face or end thereof to the head member
10 i~ a suitable manner. The head 10 has a nozzle 12 joined
by a connector member or coupling 13 with the head 10 and
telescoping a portion of a tubular section 14 forming a mixing
chamber 15. The tubular section 14 is butted against the
impingement chamber 1~ which is seated in the recess 16 con-
stituting the inner or forward end of a bore 17 extending
through the top portion of the head 10. ~he coupling 13 has
its end connected in threaded engagement in the forward end
o~ the bore or recess 16. The bore 17 has an enlarged
diameter rear end portion in which there is mo~nted an air
valve assembly 20 by means of an externally threaded bushing
21 engaging an internally threaded section at the rear
entrance to t~e bore 17.
The air valve 20, which may control any suitable
gaseous propellant material, comprises a barrel or spool
member 22 which is axially slidable in an axial bore 23
opening at the rear end of a housing or valve body forming
member 24 which constitutes an air chamber. The body
member 24 has a forward end portion 25 of reduced cross
section which extends into the rear portion of the tubular
section or impingement chamber 18. The cross section of the
3~4~5
bore 23 is progressively reduced in steps toward a forward
end portion which acts as a no~zle wi~h an elongated passage-
way 26 of relatively small cross section. The valve barrel
or spool 22 has an axial air passageway 27 with a laterally
extending passageway at the forward end which is axially
spaced from the tapered inner end portion 28. The barrel or
spool end 28 is adapted to engage a seat forming shoulder 30
in the bore 23 in closing the valve. A valve operating nut
32 has an internal shoulder at one end which rotatably
engages a fixed abutment shoulder on the bushing 21 and at
the other end is in threaded engagement with a head portion
33 on the axially slidable valve spool or barrel 22 so as
to ena~le the valve to be opened and closed by rotating the
same. The valve spool is prevented from rotating about its
a~is by pin 34 which extends into a co-operating axial slot
in the spool outer wall. The end 25 of the valve housing 24
terminates short of a pair of radial apertures or port form-
ing openings 35 and 35' ~Figure 6~ in the wall of impinge-
ment c~amber 18 (Pigures 4 and 6) through which the resins
enter the mixing chamber 15 by means of passageways 36 and
36' from trigger operated control valve assemblies 40 and 40'.
The materials which are to be mixed to form the
desired coating are supplied to the gun through infeed
suppl~ conduits 42 and 42' (Figures 4 and 7) which are
connected by means of suitable couplings or nipples 43 and
43' in threaded bores at the rear ends of infeed passageways
44 and 44' which extend axially in selector valve assemblies
45 and 45'. The selector valve assemblies are mounted in
parallel bores 46 and 46' which, in transverse section, are
--7--
~\
3 (~39g1~ ~
in a triangular forming arrangement with the upper parallel
bore 17 in the gun body or head 10 in which the air valve
assembly 20 is mounted. The inner material infeed conduits
42 and 42' have associated outer return conduit members 47 and
47' which have an internal diameter larger than the external
diameter of the inner conduits 42 and 42' and which encase
or surround the latter. The outer conduits 47 and 47' are
connected by nipple and adapter assemblies 48 and 48' to the
outer ends of the body portions 50 and 50' of the flow selector
members or valves 45 and 45' to which the inner conduits
42 and 42' are coupled so as to be in communication with
return flow passageways 52 and 52' which are generally
parallel with the passageways 44 and 44', respectively, and
which extend to generally radial or laterally directed open-
ings near the forward ends of the ~alve body members 50 and
50'. The valve body members 50 and 50' have tapered forward
end portions which are seated in sleeve members 53 and 53'.
Sleeve members 53 and 53' are in turn non-rotatably seated
in the parallel bores 46 and 46'. The rearward ends of
the sleeve members 53 and 53' are internally threaded for
engagement by the externally threaded end portion of nuts
54 and 54' which hold the valve bodies in the sleeves53 and
53' by means of engagement with an external shoulder thereon
while permitting rotation of the body members 50 and 50'
about their respective longitudinal axes. Hexagon rings
55 and 55' are secured on the rearward ends of body members
50 and 50' for manual rotation of the assemblies. The
coupled hose or material feeding assemblies turn with the
~alve body members when the selector valves are rotated.
--8--
9~13139~495
As shown in Fi~ures 4 and 7, the forward ends of the valve
bodies 50 and 50' are spaced from the forward ends of bores
46 and 46' and the sleeves 53 and 53' have axial slots 56
and 56' (Figures 4, 8 and 9), which, as shown in Figure 4,
allow inflowing fluids to pass from the passageways 44 and 44'
into the small chamber or recess 57 formed at the end of the
valve body. Axially extending passageways 58 and 58' at the
ends of the valve bodies connect wi~h generally radial passage-
ways 60 and 60' which open into one end of circumferential
slots 62 and 62' in the sleeves 53 and 53'. The slots 62 and
62' extend for approximately one quarter of the circumference
so that in the "0~" position of the valve bodies 50 and 50'
(Figures 4, 7 and 8) the fluid may flow through the passage-
ways 58 and 58', the slots 62 and 62' and into the passage-
ways 52 and 52' for return through the outer conduits.
Rotation of the valve members 50 and 50' is limited to approxi-
mately 90 by a set screw 64 which has an end extending into
a co-operating groove in the outer wall of each of the valve
boaies 50 and 50'. When the valve bodies 50 and 50' are
rotated to the alternate "OFF" position (Figure 9) the fluid
flows directly from the passageways 44 and 44' into t~e slots
62 and 62' and from there into the return passageways 52 and
52'. While in the "0~" position the passageways 58 and 58'
may be closed by operation of control valve assemblies 40
and 40' (Figures 4 and 7) through movement of the trigger
member 65.
The flow control valve assemblies 40 and 40'
(Figures 2 and 4 to 7) are mounted in a recess 67 at the
foxward end of the body or head 10 with rearward end portions
_g_
49~i
seated in parallel bores 68 and 68' w~ich are axially
aligned with the bores ~6 and 46', respectively, in which
the selector valve assemblies 45 and 45' are mounted. The
bores 68 and 68' are of smaller diameter than the bores 46 and
46'. The control valve assemblies 40 and 40' comprise
cylindrical valve bodies or housing members 70 and 70' w-nich
are seated in fixed position in the bores 68 and 68', with
suitable external seal forming rings, and piston or spool
members 72 and 72' which are axially slidable in the body
members 70 and 70'. The spool members 72 and 72' each have
an inner head portion 73 and 73' of enlarged cross section
with a tapered forward face portion 74 and 74' extending to
a section 75 and 75' of substantially reduced cross section
as to provide a relatively small cylindrical chamber 76
and 76' at the end of the valve member 70 and 70' and for
seating at the head portion 73 and 73' on a complementary
tapered edge at the end of the valve body thereby to close
the inner end of the chamber 76 and 76'. The valve housings
70 and 70' have portions 77 and 77' of enlarged diameter at
the forward or outer ends which are encased in the inner end
portions of tubular sleeve members 78 and 78' in the forward
ends of which compression springs 80 and 80' are housed. rrhe
springs 80 and 80' surround the portions 82 and 82' of the
valve spools 72 and 72' with one of their ends seated on the
ends of the valve housings 70 and 70' and the other ends
abutting the inner faces of the head portions of caps 83 and
83' which are secured in the ends of the spools 72 and 72'
so as to normally hold the valve end members 73 and 73' in
valve closing position and permitting the ends of the
--10--
~L~3~95
chambers 76 and 76' to be opened hy axial sliding movement
of the spools 72 and 72' so as to permit passage of spray
material from the chambers 57 and 57' into the chambers 76
and 76' and through openings 84 and 8~' in the walls of the
valve housings 70 and 70' which constitute openings into the
passageways 36 and 36' leading to the mixing chamber 15. These
walls have diametrically opposite openings 85 and 85l (Figures
4 and 6) for entrance of solvent material from a push type
solvent flushing valve assembly 86 which is mounted in a
cross bore 87 lmmediately below the two control valve housing
members 70 and 70' and which is best shown in Figure 6.
The housings 70 and 70' of the valve assemblies 40
and 40' are held against movement in an axial direction by
a removably mounted locking pin 90 which is slidable in a
transverse bore 92 in the body 10. The bore 92 is located
relative to the recess 67 as shown in Figure 5 so that full
diameter portions 93 and 93' of the locking pin 90 will
extend into the recess 67 when the pin 90 is fully inserted
into the bore 92 and will engag~ in transverse grooves 94
and 94' in the valve housings 78 and 78' and body members
70 and 70'. The locking pin 90 is provided with axially
spaced full diameter portions 93 and 93' permitting partial
axial movement for unlocking the valve assemblies 40 and 40'
and enabling their removal as units ~or replacement or repair.
The locking pin 90 is held in the bore 92 by a spring plunger
screw 95 (Figure 4).
The control valve assemblies 40 and 40' are
operated by pivotal movement of the trigger member 65. The
trigger member 65 carries a cross pin or cross bar 96
--11--
~C)39~ BS
tFigures 2, 4 and 7) which has its opposite ends extending
through axially extending slots 97 and 97' in oppositely
disposed wall portions of the sleeve members 78 and 78' of
the control valve housing and the valve bodies 70 and 70' and
is pivoted to the valve spool or core members 72 and 72'. The
trigger member 65 has a top end extension 98 which extends into
a downwardly opening recess 100 in the top wall of the recess
67 and forms a loose pivot point for the trigger member. The
cross pin 96 sits in an upwardly opening cross slot 101 on
the trigger and is removably held therein by a spring plunger
screw. The compression springs 80 and 80' normally hold the
trigger member 65 pivoted to the inoperative position. The
control valve assemblies are opened for resin feed by pressing
the trigger handle 65 toward the gun handle 11 which moves the
valve spool heads or end portions 73 and 73' inwardly into
engagement with the forward ends of the selector valve members
50 and 50' which closes the passageways 58 and 58' and allows
the resins to flow from chambers 57 and 57' through the
valve assemblies 40 and 40'. The rearward movement of the
valve spools 72 and 72' closes the valve openings 85 and 85'
and prevents flow of solvent regardless of position of solvent
flush valve 86.
The solvent flush valve 86 (Figure 6) is a push
type which comprises an elongated cylindrical body or housing
member 105 of a size to fit in the cross bore 87 and a core
forming spool member 106 which is slidable in the body or
housing member 105. The housing or body member 105 has
external grooves 107 and 108 forming passageways connecting
with the openings 85 and 85' in the control valve bodies 70 and
-12
~03~495
70'. A cross bore 110 in the valve housing 105 connects
the grooves 107 and 108 with the inside of the housing 105 at
a point where t~e connection is closed by the valve head
portion 112 of the spool in one position of the latter and
opened in another position of the latter. The valve is normally
held close~ by a compression spring 113 seated at one end
against the spool head 112 and at the other end against a set
screw 114 in the end of the valve body 105. The(valve spool
106 has a stem portion with a threaded end on which a button
is fastened for manual operation of the spool. Solvent is
supplied to the valve 86 through a passageway 115 (Figures
3 and 4~ to which there is suitably connected a solvent
supply line. The passageway 115 connects with an opening 116
into the interior of the valve housing 105 at the same point
as the outflow ports formed by the bore 110.
In using the illustrated form of the device in a
typical spray coating operation employing a ~oam plastic, the
kwo resin components which are to be mixed and discharged
through the nozzle 12 by an air propellant are fed from a
supply tank through the conduits 42 and 42' with the material
being heaked to the proper temperature required for the desired
mixing. The manually operated selector valves 45 and 45' may
be adjusted to recirculate the resin components through the
supply tan~s without passage of the resin components through
the control valves 40 and 40' as shown in Figures 4 and 8
of the drawings. When it is desired to operate the gun for
spraying or dispensing the mixed resins the selector valves
45 and 45' are first rotated to the position shown in
Figures 4 and 8. With the trigger 65 in the normal
-13-
9L~3~4~S
inoperative position shown in solid lines in Figure 4, the
valve assemblies 40 and 40' remain in the position shown in
Figures 4 and 7 and the resin components are recirculated
through the selector valves 45 and 45' as shown. This is the
normal "OFF" position of the control valves 40 and 40'.
In this position of the valves 40 and 40' the solvent line
is opened for passage of solvent through the valves and into
the mixing chamber 15 to flush out the same upon operation
of the solvent control valve ~6.
When the trigger 65 is swung toward the handle 11
to the fully "ON" position the valves 40 and 40' are in the
position indicated by dotted line in Figure 7, and the valve
ends are closed on the ends of the selector valves 45 and
45' so that the resin materials flow through the selector
valves 45 and 45' and through the control valves 40 and 40'
~o the mixing chamber 15. In this position of the valves 40
and 40' the solvent passageways 85 and 85' are blocked off
by the valve spools 72 and 72'.
The selector valves 45 and 45' may be rotated
90 to the position shown in Figure 9 which will prevent the
-
flow of resin materials into the chambers 57 and 57' and
allow return of the resin materials through the passageways
52 and 52', while valves 40 and 40' can be opened sufficiently
to allow the solvent flush valve 86 to be operated to flush
out the passageways and the mixing chamber. The air or other
propellant control valve 20 can be manually opened and closed
as desired.
The valve assemblies 40 and 40' are both held in
the bores 68 and 68' by the loc~ing pin 90. The trigger 65
-14-
~0;~49S
may be released from the pin 96 and removed, whereupon thevalve assemblies 40 and 40' may be readily removed, ~y with-
drawing the locking pin 90, as complete units from the bores
68 and 68' for cleaning or replacement of parts. The selector
valves 45 and 45' are, of course, adjusted to the position
shown in Figure 9 when the control valve units or assemblies
40 and 40' are to be removed so as to prevent passage of the
resin components into the bores 68 and 68' and enabling the
same to be recirculated through the supply tanks.
While the apparatus has been illustrated and des-
cribed as a spray gun type dispenser, it is not intended that
its use be limited to a spraying operation. It may also be
used for pouring or frothing operations. For a pouring
operation it is necessary to remove the nozzle and replace the
same with a plain spout forming piece of pipe or hose (not
shown) which may contain a motor driven agitator for the
purpose of mixing the plastic components. For the frothing
operation a different mixing head i5 employed havin~ a
spiral coil for dispensing the foam material.
~hile particular materials and specific details
of construction have been referred to in describing the form of
the apparatus illustrated it will be understood that ot~er
materials and e~uivalent structural details may be employed
within the spirit of the in~ention.
-15-
