Note: Descriptions are shown in the official language in which they were submitted.
SYNTHETIC RESIN PATCH GUN
TECHNICAL FELD
The invention relates to a mechanism or gun for dispensing
fluids and more particularly to a patch gun which mixes fluidic com-
ponents and dispenses a reacted flui~. The dispensing gun has two
spaced apart housings connected by rigid tubing.
BACKGROUND OF THE INVENTION
In many manufacturing processes and specifically in the wood
products industry, it is often desirable to mix fluidic materials in
order to form putties or glues. For instance, in plywood manufacture,
it is desirable to fill knot holes and other defects in the surface of
plywood panels with a mixture of fluidic components such as a resin
and a catalyst. After a knot hole or defect is filled, the plywood sur-
face may be planed or sanded to provide a smooth finish. To mix the
resin and the catalyst, a device must be provided which sufficiently
commingles the fluidic components for delivery through a mixing tube
for eventual discharge into a knot hole or defect.
In the construction, insulation and packaging industries, the use
of sprayed urethane foams is rapidly expanding. This relatively inex-
pensive product has proved to be a highly valuable insulating and
packaging material for a number of reasons. Its resiliency, high com-
pressive strength and its excellent dimensional stability make it an
excellent packing material for shipping relatively fragile items and
cartons where rough handling may be encountered. It has extremely
low heat transmitting properties, making it an excellent insulation
material. Relatively extreme temperatures do not greatly affect it.
It does not deteriorate rapidly, thus providing a long service life.
Whether dispensing a putty or glue in the wood products indus-
try or dispensing a sprayed urethane f oam in the construction,
insulation and packaging industry, the requirements for the ideal dis-
pensing gun are similar.
A resin and catalyst when commingled form a mix which sets
up or hardens quite rapidly. When the resin and catalyst are to be
mixed, the residue must be quickly moved out of the inside of a dis-
pensing gun if the gun is not to become jammed or clogged. A dis-
pensing gun must receive the resin and the catalyst from separate
supplies and thoroughly mix the fluidic components to dispense a uni-
formly and thoroughly mixed reacted fluid. Although it is desired to
have the components thoroughly mixed within the gun so that a thor-
oughly mixed reacted fluid is dispensed, this requirement creates a
problem. Thorough mixing of the components to form a reacted com-
ponent means that the solidification process will begin within the gun.
With partial solidification of the reacted fluid occurring within the
gun, experience has shown that the tubes and/or cavities which con-
vey the fluids will become partially or fully clogged and unusable. A
clogged condition degrades the ability of the dispensing gun to per-
form. It becomes necessary to either clean or dispose of the clogged
components so that a dispensing gun providing high quality perfor-
mance can be rapidly put back into use.
Sperry et al. in U.S. Patent No. 4,469,251 provides a fluid dis-
pensing apparatus having a detachable mixing chamber and a control
assembly. The detachable mixing chamber may be removed for
replacement when necessary with a minimum of interruption to the
dispensing operation and the associated loss of productivity. The con-
trol assembly includes a hollow barrel section having a piston slidably
disposed therein. A pressurized gas source is selectively placed in
fluid communication with a forward and a rearward portion of the
barrel section to effect movement of the piston. This design is disad-
vantageous because the mixing chamber is relatively close to the
main body of the dispensing gun where the moving parts are located.
Therefore, the danger exists that any clogging or partial solidification
within the mixing chamber may result in clogging or fouling of the
moving parts resulting in the necessity of dispensing apparatus to be
removed from service for cleaning. A small reservoir of solvent is
also provided to purge the mixing chamber.
Brooks et al. in U.S. Patent No. 4,11~,551 discloses a purgable
dispensing gun for polyurethane foam. Separate independently opera-
ble valves are disposed within a disposable nozzle for isolating the
interaction of the fluidic components to the nozzle. Locating the
disposable nozzle or mixing chamber relatively close to the dispensing
gun's housing is disadvantageous because if one or both of the check
valves should fail, the reacted fluid need travel but a very short dis-
tance to clog the main body of the gun. A mechanism is provided for
purging settable product fluid constituents from important gun parts.
Larson in U.S. Patent No. 4,129,231 discloses a portable hand
held dispensing gun for dispensing multiple fluidic components into a
mixer. Flexible fluid transporting tubes transport the fluids to a mix-
ing chamber which is partially formed from the housing or head
assembly of the gun. This arrangement is disadvantageous because
the mixing chamber is disposed at the forward end of the head assem-
bly which contains the moving components of the gun. Furthermore,
the flexible tubes are deformed by a trigger lever to form a seal that
restricts fluid flow. Prolonged actuation of the trigger mechanism
may weaken or cause cracking within the flexible tubing. Since the
flexible tubing is hidden from view, any leakage within the flexible
tubing will not be detected until after a noticeable amount of leakage
has occurred which would allow for the possibility of partially solidi-
fied components flowing into and clogging the moving components of
the gun. One of ordinary skill in the art would find it difficult to
practice the Larson device, which reguires flexible tubing that will
not excessively deform or burst when subjected to conventional fluid
pressures, but will deform to positively seal the tubing by use of a
simple lever.
The prior art fails to contemplate a dispensing gun having a
first housing which contains the moving components of the gun, a
second housing containing a mixing chamber disposed well apart from
the first housing and rigid tubing to connect the housings which is
exposed to permit easy visual inspection for defects or leakage within
the tubing.
UMMARY OF THE INVENTI~N
The invention relates to a dispensing gun having a first housing
or main body which contains the moving components of the gun, and a
second housing or mixing chamber which is spaced well apart from
the first housing. The first housing is connected to the second housing
by a plurality of rigid, exposed tubes. The second housing is also con-
nected to a disposable nozzle having a mixing member. The first
housing has inlet ports for the resin and catalyst, respectively, valve
members for actuating the flow of the fluidic components through the
first housing, and a handle which contains a trigger valve mechanism.
A trigger actuates the trigger valve mechanism and a piston cylinder
arrangement responsive to actuation of the trigger mechanism actu-
ates the valve members to control flow of the resin and catalyst.
Further, the gun design is remarkably lightweight due to its compact
size and mainly aluminum construction.
Various advantages and features of novelty, which characterize
the invention are pointed out with particularity in the claims annexed
hereto and forming a part hereof. However, for a better understand-
ing of the invention, its advantages, and objects obtained by its use,
reference should be had to the drawings which form a further part
hereof, and to the accompanying descriptive matter, in which there is
illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side elevational view of one embodiment of a syn-
thetic resin patch gun in accordance with the present invention;
Figure 2 is a top plan view of one embodiment of the invention
as shown in Figure l;
Figure 3 is an exploded perspective view of the invention as
shown in Figure 1;
Figure 4 is a top plan view of the first housing or body of the
invention as shown in Figure l;
Figure 5 is a side elevational view of the first housing of the
invention as shown in Figure 4;
Figure 6 is a bottom plan view of the first housing of the inven-
tion as shown in Figure 4;
Figure 7 is an elevationaX view of one side of a trigger valve
mechanism of the invention as shown in Figure 3;
Figure 8 is an elevational view of the other side of the trigger
valve mechanism as shown in Figure 7;
Figure 9 is an exploded side elevational view of a ball needle
valve or flow valve mechanism of the invention as shown in Figure 3;
Figure 10 is a top plan view of an air cylinder housing of the
invention as shown in Figure 3;
Figure 11 is a side elevational view in partial cross-section of
the air cylinder h~using as shown in Figure 10;
Figure 12 is a front elevational view of the air cylinder housing
as shown in Figure 10;
Figure 13 is a side elevational view of a manifold of the inven-
tion as shown in Figure 3;
Figure 14 is a front elevational view of the manifold as shown
in Figure 13;
Figure 15 is a side elevational view of an end cap defining a
mixing chamber of the invention as shown in Figure 3;
Figure 16 is a front elevational view of the mixing chamber as
shown in Figure 1~;
Figure 17 is a perspective view of a preferred embodiment of
an air cylinder housing assembly of the invention;
Figure 18a is a top plan view of the preferred embodiment of
an air cylinder housing as shown in Figure 17;
Figure 18b is a side elevational view of the air cylinder housing
as shown in Figure l~a;
Figure 18c is a bottom plan view of the air cylinder housing as
shown in Figure 18a;
Figure 19 is a side elevational view of the preferred embodi-
ment of an end cap of the air cylinder housing assembly aS shown in
Figure 17;
Figure 20 is a perspective exploded view of a portion of the
preferred embodiment of the synthetic resin patch gun;
Figure 21a is a side elevational view of the preferred embodi-
ment of a handle as shown in Figure 20;
Figure 21b is a front elevational view of the handle as shown in
Figure 21a;
Figure 21c is a top plan view of the handle as shown in
Figure 21a;
Figure 22 is a side elevational view of an alternate embodiment
of the rigid tubing of the manifold;
Figure 23 is a side elevational view of a preferred embodiment
of a ball needle valve assembly or flow valve mechanism as shown in
Figure 20;
Figure 24 is an exploded side elevational view of the preferred
embodiment of the ball needle valve assembly as shown in Figure 23;
Figure 25 is a front elevational view of a rubber plug of the
invention;
Figure 26 is a side elevational view of the rubber plug as shown
in Figure 25;
Figure 27 is a side elevational view of a connecting member;
and
Figure 28 is a side elevational view of a storage cap.
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings wherein like numerals indicate like
elements, a synthetic resin patch gun 10 in accordance with a first
embodiment of the present invention is shown in Figure 1.
Figure 1 illustrates the first embodiment of the synthetic resin
patch gun. Synthetic resin patch gun 10 is connected to a pressurized
fluid source. Preferably, the fluid is air. The major components of
synthetic resin patch gun 10 are a first housing or body 20, a manifold
30, a nozzle assembly 40, a flow valve mechanism 50, an air cylinder
assembly 60, a handle 70, and a trigger assembly 80.
Figure 2 shows a source of first fluid that is preferably Resin A
operatively connected to the patch gun and a source of a second fluid
that is preferably Resin B operatively connected to the patch gun. A
second housing or mixing chamber 71 is defined by the connection
between manifold 30 and nozzle assembly 40. The manifold is a
connecting mechanism that spaces the first housing 20 a substantial
distance apart from the second housing 71 and is preferably made of
stainless steel. The manifold 30 directly supports the mixing chamber
71.
It is desired to have the mixing chamber 71 substantially
spaced apart from the first housing 20 which contains at leas~ some of
the moving parts of the gun. If the gun's mixing chamber 71 clogs
during use, it is designed to be easily opened and cleaned by scraping
with a knife, screwdriver or other readily available implement. Other
designs in common use must be dismantled, the moving parts thor-
oughly cleaned, and the reacted chemicals removed, if the gun has
been idle for any length of time before being able to use the gun
again.
Figure 3 is a perspective exploded view of the synthetic resin
patch gun. The nozzle asse~lbly 40 includes a nozzle 41 having an
internal bore (not shown) that runs its entire length and a mixing
member 42 disposed within that bore. Nozzle 41 includes a straight
portion 41a, an angled portion 41b and a dispensing tip 41c. A com-
pression nut 43 is connected to an adapter 45 in any conventional
manner, preferably by a threaded connection, and a hollow ferrule 44
is sandwiched therebetween. Nozzle 41 passes through compression
nut 43 and ferrule 44, after which compression nut 43 is threaded on
portion 45a of adapter 45. Nozzle assembly 40 is then connected to a
cap nut 46 in any conventional manner, preferably by a threaded con-
nection. As best shown in Figure 15, cap nut 46, preferably made of
stainless steel, includes a nut portion 47 having an internal threaded
portion 47a and a body portion 48 having a tapered portion 48a, an
internal threaded portion 47b and an outer knurled surface 49. Cap
nut 46 is connected to manifold 30 in any conventional manner, pref-
erably by a threaded connection. A purge fluid to purge mixing cham-
ber 71 and nozzle assembly 40 is provided. The flow of purge fluid is
controlled by valve 72. Valve 72 is preferably a conventional valve
such as a 3/8" Whitey Ball Valve. Valve 72 is connected to body 20 by
connecting members 73a, 73b.
.
As best shown in Figure 13, manifold 30, preferably made of
stainless steel to resist the fluidic components and wear from use and
cleaning, includes a plurality of elongate, rigid tubes 31, a back plate
34 and a front plate 35. Each of the elongate, rigid tubes is connected
at one end to the back plate and at the other end to the front plate.
Front plate 35 has a threaded surface 35a and a front surface 35b.
Cap nut 46 connects to threaded portion 35a of front plate 35 to form
mixing chamber 71. Manifold 30 is connected to body 20 in any con-
ventional manner, preferably by a threaded connection. Back plate
34 has a plurality of through holes 34a and body 20 has a plurality of
threaded bores through which threaded fasteners pass to connect body
20 to manifold 30.
Figures 4, 5 and 6 illustrate top, side and bottom views of body
20. Body 20, which is preferably made of aluminum, has a first cavity
21 and a second cavity 22. First cavity 21 has a threaded inlet 21a
and a threaded outlet 21b. Cavity 22 has a threaded inlet 22a and a
threaded outlet 22b. A first fluid or Resin A flows into the patch gun
10 via inlet 21a and a second fluid or Resin B flows into the patch gun
10 via inlet 22a. As shown in Figure 5, a plurality of pivot connec-
tions 24 depend ~rom the lower portion of body 20. Each pivot con-
nection 24 has a through hole 24a. A plurality of flow valve mecha-
nisms 50 are provided to control the flow of Resin A and Resin B
through the patch gun.
Figure 9 illustrates a representative flow valve mechanism 50.
Flow valve mechanism 50 includes a ball 51, preferably made of tung-
sten carbide, connected to a needle 52 in any conventional manner,
preferably by brazing or soldering, a compression spring 53 surround-
ing a portion of needle 52, and an assembly nut 54 having a threaded
portion 54a that threads into one of the resin cavities 21, 22. Assem-
bly nut 54 includes a nut portion 54b and a cavity 54c having a for-
ward portion in which one end cf the compression spring i~, disposed, a
central bore through which the needle 52 passes, and a rear threaded
portion. A packing nut 55 includes an internal bore through which
needle 52 passes, a nut portion 55b and an external threaded portion
55a that threads into the rear threaded portion of cavity 54c. A
collett 56 having a nut portion and a threaded portion, a collett holder
58 and an 0-ring 57 which acts as a spacer are also included in flow
valve mechanism 50. The needle 52, which passes through the collett
56 and the collett holder 58, is secured to the collett 56 by the com-
pression of the threaded connection between collett 56 and collett
holder 58. A valve seat 59 of any conventional material, preferably
TEFLON-type material, is disposed within each of the body cavities
21, 22 and contacts the ball 51 of flow valve mechanism 50.
As shown in Figure 3, also connected to body 20 is handle ~0.
Handle 70 includes a cavity 85 having a cavity inlet 85a and a first
cavity outlet 85b. A hose barb 86 is connected to cavity inlet 85a to
connect a hose from the pressurized fluid source. Trigger assembly 80
is associated with body 20 and handle ~0. The trigger assembly 80
includes a trigger 81 connected to pivot connection 24 by any conven-
tional means, preferably by a trigger pin 81a that slides through the
plurality of through holes 24a associated with pivot connections 24.
The trigger 81 actuates a trigger valve 82. Trigger valve 82 includes a
sleeve 83 and a stem 84 substantially disposed within the sleeve. The
trigger valve is readily available from Waite Machine Co. as Part No.
44 for Model RP100 patchguns. Disposed along the sleeve 83 are a
plurality of 0-rings, which frictionally retain the trigger valve 82
within cavity 85 and provide a sealing function. Sleeve 83 has an
inlet 83a communicating with the pressurized fluid source through
cavity inlet 85a. As best shown in Figure 8, sleeve 83 also has a first
outlet 83b and a second outlet 83d. Stem 84 having a stem head 84a is
shown in Figure 8 in its extended or biased position. The head of the
stem is extended due to the biasing force applied to it by a biasing
member (not shown). When trigger 81 is moved rearwardly, it con-
tacts head 84a and moves the stem 84 rearwardly against the biasing
force. This rearward motion results in inlet 83a being placed in fluid
communication with first outlet 83b.
As best shown in Figure 10 air cylinder housing assembly 60
includes a base portion 61a and the cylinder portion 61b having a
cylindrical projection 62. Cylindrical portion 62 has a through bore
62a which is in fluid communication with cylinder cavity 63. As
- 10 -
shown in Figure 3, air cylinder housing assembly 60 is operatively con-
nected to flow valve mecha{lism 50 and connected to handle 70. A
connector ?7 has an internal bore threaded at both ends. A yoke 75
having a plurality of grooved portions 76 is connected to one end of
connector 77 by a threaded fastener. The other end of connector 75
passes through through bore 62a and is connected to piston 66 by a
threaded fastener. Grooved portions 76 mate with recesses on flow
valve mechanisms 50.
Figures 10, 11 and 12 illustrate top, side and front views of air
cylinder housing 61. A fluid passage 64 having a vertical portion 64a
and a horizontal portion 64b is disposed within air cylinder housing 61.
Base portion 61a has a plurality of through holes 65 which allow air
cylinder housing 61 to be connected to handle 70 in any conventional
manner preferably by threaded fasteners. As shown in Figure 3 a pis-
ton 66 having an O-ring disposed in a groove therein is located within
cylinder cavity 63. An end cap 68 having a rear portion 68a which
vents to the atmosphere is connected to air cylinder housing 61 in any
conventional manner, preferably by a threaded connection. An O-ring
and a compression spring 67 are disposed between piston 66 and an
inner wall of end cap 68.
Figures 13 and 14 illustrate side and front views of the mani-
fold 30. Figures 15 and 16 illustrate side and front views of cap nut 46
which connects to front plate 35 to form a mixing chamber.
Figure 1~ illustrates a preferred embodiment of the air cylinder
housing assembly. Air cylinder housing assembly 160, preferably made
of aluminum, includes an air cylinder housing 161, a piston 66 and an
end cap 168 connected to the air cylinder housing 161 by a snap ring
169. As in the previous embodiment piston 66 has a groove with an
O-ring disposed therein and is connected to one end of connector ~7
by a threaded fastener.
Figures 18a, 18b and 18c illustrate top, side and bottom views
of air cylinder housing 161. Air cylinder housing 161 includes a first
fluid passageway 64 and a second fluid passageway 164. A cavity 163
is disposed within a cylinder portion 161b. Fluid passageway 164 is in
fluid communication with cavity 163 through an opening 163a.
Figure 19 illustrates a preferred embodiment of an end cap 168.
End cap 168 has a rear projection 168a and is preferably made of alu-
minum. An O-ring and snap ring 169 are placed in the groove on end
cap 168 which is partially inserted into cavity 163 and retained within
the air cylinder housing 161 by snap ring 169. The snap ring is prefer-
ably made of a spring steel alloy.
Figure 20 illustrates a preferred embodiment of the flow valve
mechanism 150 and a preferred embodiment of the handle 170 prefer-
ably made of cast aluminum. Handle 170 includes a cavity 85 having a
trigger valve mechanism 82 substantially disposed therein. Handle
cavity 85 has a cavity inlet 85a, a first cavity outlet 85b and the sec-
ond cavity outlet 85c. As best shown in Figures 7 and 8 trigger valve
inlet 83a is in fluid communication with cavity inlet 85a. The plural-
ity of O-rings disposed on sleeve 83 provide a fluid sealing function so
a first outlet 83b is in fluid communication with first cavity outlet 85b
and a second outlet 83d is in fluid communication with the second
cavity outlet 85c. When the stem 84 is in the extended biased posi-
tion, second outlet 83c is in fluid communication with cavity inlet 85a
and second cavity outlet 85c, therefore piston 66 is biased forwardly
by the pressurized fluid. When the trigger 81 is depressed thereby
depressing stem 84, inlet 83a is in fluid communication with first out-
let 83b which is in fluid communication with second handle outlet 85b
and fluid passageway 64 to move the piston 66 rearwardly. This rear-
ward movement of piston 66 moves the connector 77 and the yoke 75
rearwardly also. Rearward movement of the yoke 75 rearwardly dis-
places balls 51 of flow valve mechanisms 50 and permits Resins A and
B to flow through the main head of the synthetic resin patch gun.
Releasing trigger 81 allows stem 84 to return to the- biased forward
position which places inlet 83a in fluid communication with second
trigger valve outlet 83c and the piston 66 is moved forwardly by the
pressurized fluid to cease flow of Resins A and B.
Figures 21a, 21b and 21c illustrate side, front and top views of
a preferred embodiment of the handle.
Figure 22 illustrates a preferred embodiment of the elongate
rigid tubes preferably made of stainless steel for use in the manifold.
Tubes 131a which carry Resin A and Resin B have different internal
diameters and tube 131b carries a purge fluid. It is contemplated to
have the tube 13~ a transporting Resin B have a smaller internal diam-
eter than the tube 131a transporting Resin A to provide the proper
proportion of Resin B to Resin A in the mixing chamber. The tubes
131a, 131b are preferably exposed to provide easy visual inspection
thereof for leakage aS opposed to having tubing which is hidden from
view. Exposed tubing has the advantage of early detection of leakage,
therefore the possibility of Resins A and Resin B reacting prior to
reaching the mixing chamber and fouling the moving components of
the patch gun is minimized.
Figures 23 and 24 illustrate a preferred embodiment of the flow
valve mechanism. Figure 23 illustrates the flow valve mechanism in
an assembled configuration and Figure 24 illustrates flow valve mech-
anism 150 in an exploded configuration. Preferably, flow valve mech-
anism 150 is made of stainless steel except for the needle 152 and ball
151. Needle 152 and ball 151 are preferably a unitary structure made
of hardened steel. Needle 152 has a ball 151 disposed at its forward
end, a threaded portion 152b disposed at a rearward end and an adjust-
ing hole 152a disposed at an intermediate location. Needle 152 passes
through assembly nut 154 and threads along portion 152b into threaded
bore 157a of tension nut 157. Flow valve mechanism 150 threads into
body 20 within one of cavities 21, 22 along threaded portion 154a.
The parts of flow valve mechanism 150 rearward of nut portion 154b
are exposed and extend beyond body 20. If excessive clearance or
interference exists at the point of contact between valve seat 159 and
ball 151, then a thin rod may be inserted into adjusting hole 152a and
rotated while tens~on nut 157 is held to adjust the clearance or inter-
ference accordingly.
Figures 25-28 illustrate components for use with the synthetic
resin patch gun when a storage mode is desired. Figures 25 and 26
illustrate front and side views of a plug 91 having a taper 91a and a
rear surface 91b. Plug 91 is preferably made of rubber and has a taper
91a which is complementary to taper 48a in cap nut 46 as shown in
Figure 15. The rubber preferably has a durometer rating in the range
- 13 -
of 50 to 65. The rear portion 91b of plug 91 is of a shape complemen-
tary to front surface 35b on front plate 35 as shown in Figure 13.
Plug 91 occupies substantially the entire mixing chamber and forms a
fluid tight seal.
Figure 27 illustrates a connecting member 92 having a forward
threaded portion 92a and a rear threaded portion 92b. Figure 28 illus-
trates a storage cap nut 93 having an internal thread 93a. When it is
desired to remove the Resin A and Resin B sources from the patch
gun it is necessary to seal off body inlets 21a and 22a. A connecting
member 92a is connected to body inlet 21a along portion 92a and
another connector member 92 is connected into body inlet 22a along
portion 92a. A storage cap nut 93 is then connected to the rear
threaded portion 92b of the connecting member 92.
Further, the gun design is remarkably lightweight due tO its
compact size and mainly aluminum construction.
One of the fluidic components, Resin B, is preferably polymeric
isocyanate or MDI. Resin A is preferably a filled polyol. An inorganic
filler is contemplated to "fill" Resin A to provide characteristics such
as viscosity. MDI is sensitive to moisture, even moisture in the air.
Hence, the need for fluid-tight seals exists when storing the gun. The
use of storage cap nuts 93 and/or plug 91 provides the capability of
sealing the gun in a fluid-tight fashion. This fluid-tight storage capa-
bility during shut down mode keeps the MDI ~dry~, thus making it
unnecessary to dismantle and clean the gun's moving parts at the time
of the next start up.
Numerous characteristics, advantages, and embodiments of the
invention have been described in detail in the foregoing description
with reference to the accompanying drawings. However, the disclo-
sure is illustrative only and the invention is not limited to the precise
illustrated embodiments. For example, the O-rings and threaded fas-
teners are of conventional design and may be composed of any con-
ventional material. Various changes and modifications may be
effected therein by one skilled in the art without departing from the
scope or spirit of the invention.
