Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates gererally to sealant
: applicators and, specifical.ly tc i~proved apparatus for heating .~ :
and ext.rudlr.g fluid sealant material onto a work. surface, which
ir,cl.udes a portabl6 feed cha~er and pl~p ~hich is capabl.e of
receiving sealant in bulk form and heating it so that i.t may ~e
extruded thrGugh a hos6 un.der pressure to a pres2ure gun which
oFerates t.o apply the fluid se.alant ~.aterial cnte a wcrk su.rface.
In recent years, portable sealant applicators ha~e been :~
dev610ped for applyirg but.yl tape seala.nts and other rubher-based,
hot-.7nelt sealants. Such portable applicatGrs prcvi.d.e va:riable ~.
extrusic.n rates of hot ~eal.ants at various temperatures. Such ~.
h~t. sealants are nor~.ally e~.ployed for m.anufacturing insu.lated
~lass, for applying bed.din.g co.7r.~Gunds, for sealing pressure and :
vacuu7.~. vessels, for insulation of automot:i.ve windshields, and for
the applicat.ion of ex~ansion joir.ts in highways.
Although such prior art devices are. to scme extent
portable, they hav-e ~7arious draw~Lacks. Typically, rope-shaped ..
sealant must be manually fed into the sealant applicator ar.d the
rope sealant. is forced by a rotating auger into an extrusion die :~
at the ehd therecf. How6~7er, rope-shaped se.alant co~ts about
twice as much as sealant in bulk form, and the opera.tcr ~.u~t. con-
tinually ~ar.,ually supply the sealant to the applicator. It ~ .:
would, therefore, ~e hiyhly desirable to provide a portable
sealant applicat.or whi~h is capa~le of using bulk sealant insteaQ
o continual.ly fed rope-shaped sealant.
In addition, su~h prior art sea].ant applicators typi~
cally include a.n. auaer arranaem6nt for fcrcing the rope-shaped
seal.ant through an e~t.rusion die at the end thereof. Ho~7ever,
the auger arrangement cupplies the sealant mat.eri.al to the die
und.er limited ~ressure ard, therefore, limits the lenath and the : :
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type of die which may be employed. Such limited pressure also prevents
a hose extension from being employed. Accordingly, it would be highly
desirable to provide a portable sealan~ applicator using bulk material ;~
which is also capable of extruding fluid sealant material through a ~ ~-
lightweight portable hose extension under different a~ounts of pressure
to vary the rate of extrusion.
Moreover, such prior art sealant applicators normally require
two hands to oeprate and manipulate, while at the same time, the operator
must guide the rope-shaped sealant into the applicator. As a result, it
is difficult for a single operator to perform all of these Eunctions and ~-
still properly orient and manipulate the appllcator. Moreover, although ~;~
such prior art sealant applicators are to some extent portable, they are ~ ;
heavy and unwieldy and, therefore, difficult to manipulate and line up -~
with the work surface on which the sealant is to be appliedn Accordingly, ~ `
it would be highly deslrable to provide a truly portable sealant appli-
cator which may be easily and accurately manipulated by a single operator.
It should also be pointed out that such prior art sealant appli-
cators which are of the portable type are not intended for high production
use due to the li~itations of supplying rope-shaped sealant. More parti-
' I .
cularly, the rope-shaped sealant is typically supplied in one pound
bundles and therefore must continually be resupplied to the sealant appli-
cator and such applicators are therefore not intended for high production
operat~ons. It would also be highly deslrable to provide a portable
; sealant applicator which would be suitable for high production work.
According to a broad aspect of the present invention, an appara~
tus is provided for heating and extruding flowable sealant material~onto
a work surface comprising: a portable feed chamber having an opening for
recelving sealaDt materlal ln bulk form and an outlet for supplying
sealant material in a fluid state to a pump device; first heating means
disposed with respect to the feed chamber for heating the bulk sealan~t
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material contained therein to a fluid state having a pumpable vlscosity;
conveyor means disposed withln the feed chamber for forcing the fluid
sealant material through the outlet of the feed chamber under pressure
into the pump device and the pump device being disposed outside of the
feed chamber with respect to the outlet for forcing the fluid sealant
material under pressure through a heated hose, the pump device including
second heating means for maintaining the sealant material passing there-
through at a predetermined temperature level; the pump device further
including a rotor and a stator and being of the positive displacement
type naving progressing cavities formed as the rotor turns within the
stator; the heated hose being connected to the pump device for receiving `~
fluid sealant material supplied therefrom under pressure, the heated hose
including third heating means for maintaining the sealant material passing
therethrough in a fluid state; feedback means connected between the pump
device and the heated hose for returning fluid sealant materlal to the
feed chamber when the pres~ure in the heated hose reaches a predetermlned
level, the feedback means lncludlng fourth heat:Lng means for malntalning
the sealant materlal passlng therethrough in a fluld state; and means
connected to the heated hose for applying the fluid sealant material onto ;
a work surface.
By a variant of thls lnvention, the feedback means includes a
return port formed in the feed chamber and a pressure valve connected to
the pump device, the pressure valve being operatlve to allow the passage
of fluld sealant materlal from the pump device to the return port when the
pressure in the hose reaches a predetermined level.
By another variant, the apparatus further includes control means
~. .
~ for controlling the temperature of the first, third, and fourth heating
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means relative to the second heating means of the heated hose. `~:
- By a further variant, the pump device is a Moyno-type pump, the -~
30 conveyor means includes a rotatable screw conveyor, the Moyno pump and ; `~
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the screw conveyor have a common drive, and the pump device is operative
to force the fluid sealant material through the heated hose at predeter~
mined pressures.By ye ;~
~! By yet another variant, the feed chamber includes a heated grid
adjacent the opening for supporting the bulk sealant material while it is
being heated to a fluid state.
By still another variant, the first heating means of the feed
chamber includes heating elements mounted on the outer walls of the feed
chamber.
By a further variant, the applying means includes a handgun
having a removable nozzle for extruding the fluid sealant material under
pressure onto a work surface.
By a variation thereof, the handgun further includes heating
means connected thereto for maintaining the sealant material in a fluid
state.
By a further variation, the noYzle of the handgun is removable
so that dlfferent size nozzles may be employed ln conJunction with the
handgun to vary the amount and conflguration of sealant material which
is extruded.
In accordance with broad aspects of this invention, an
improved sealant applicator is provided for heating and extruding flow-
able or fluid sealant material onto a work surface and includes a heated
feed chamber, a posltlve displacement pump mounted on the feed chamber,
a heated hose connected to the outlet of the p~mp, and a handgun connec-
~ ted to the heated hose Eor applying a fluid sea:Lant material onto a
;; suitable work surface. Advantageously, the feed chamber includes an
:; opening for receiving sealant material in bulk form, and an outlet for
~i ,
dispensing sealant material in a fluid or flowable state. Heating
elements are disposed on the outer wall of the feed chamber for heating
the bulk sealant material contained therein to a fluid state having a
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pumpable consistency or viscosity. The hose, whlch includes a heating
coil surrounding the length of the hose, is connected to the outlet of
the feed chamber and pump for receiving the heated fluid sealant material
dispensed therefrom, and the heating coil of the hose operates to main-
tain the sealant material passing therethrough in its fluid state. A
rotatably driven screw conveyor is disposed in the lower portion of the
feed chamber for supplying the fluid sealant material to the pump which
forces the heated fluid sealant material under pressure through the
heated hose to the heated handgun. The heated handgun is light in weight,
easy to manipulate, and is provided with a removable nozzle which may be
changed for applying various configurations of the fluid sealant material
onto different size work surfaces.
The sealant applicator of one aspect of the present invention
is portable as the feed chamber is mounted on wheels or any other suitable
transportLng means. The feed chamber further includes a materlal feed-
back arrangement connected between the pump and the Eeed chamber Eor
returning fluld sealant materlal to the feed chamber when the pressure in
the heated hose reaches a predeter~ined level or when the handgun is
temporarily not in use. A pressure valve in the feedback arrangement
operates to allow the passage of fluid sealant material from the pump
back to an inlet port of the feed chamber when the pressure in the heated
hose reaches the predetermined level. In addition, the pump and the
feedback arrangement are provided with suitable heating means for main-
talning the sealant materlal in lts fluld state and at a predeternlined
temperature level.
Advantageously, the sealant applicator of an aspect of the ~ ~-
present invention not only is portable, but also is capable of receiving
sealant material in cheaper bulk form and heating it to its fluid or
flowable state. This provides a great savings, as the cost of sealant in
bulk form is approximately half the cost of rope-shaped sealant. More-
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over, the portable sealant applicator of an aspect of the present inven-
tion operates under a range of high pressures and volumes to vary the
rate of sealant extrusion, and such pressure operation allows greater
flexibility with respect to the size nozzle ~md the length of delivery
hose employed with the pressure gun. In addition, the handgun of the
portable sealant applicator of an aspect of the present invention is
light in weight, simple for a single operator to manipulate and to line
up properly with the working surface to which the sealant is to be applied,
and is not difficult to manipulate as are prior art sealant applicators.
Further, the portable sealant applicator of an aspect of the present
invention may be employed at high-production facilities, since the feed
chamber is capable of holding a relatively large quantity of sealant.
Generally, the portable sealant applicator of an aspect of the present
invention is cheaper to operate because of :Lts use of sealant in bulk
form, has a high pressure range under which the sealant may be applied,
has unlimited bulk sealant capacity, and is simpler to manipulate in
applying the sealant to the working surface.
In the accompanying drawing,
Figure 1 is a side elevational view of the feed chamber, outlet
means and feedback arrangement of the sealant applicator of one variant
of the present invention;
Figure 2 is an elevational view of the internal arrangement of
the feed chamber used in the sealant applicator of one variant of the
present invention;
Figure 3 is a diagrammatic view of the portable sealant appli-
cator of a variant of the present invention including the feed chamber, ~;
the heated hose, the pressure gun, and the control box;
Figure 4 is a perspective view in detail of a removable noæzle `
employed with the pressure gun of a sealant applicator of a variant of
the present invention; and
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Figure 5 is a side view of a positive displacement pump
employed in the sealant applicator of a variant of the present invention, ;
Referring first to Figure 3, there is showll a diagrammatic
view of the portable sealant applicatar of one aspect of the present
invention including a feed chamber 10, pump 46, a feedback arrangement
50, a heated hose 12, a handgun 14, a control box 16, and a belt drive
arrangement 18 for the feed chamber 10.
Referring now to Figures 1 and 2, there is a clear illustration
of the feed chamber 10 of a portable sealant applicator of an aspect of
the present invention. The feed chamber 10 includes an opening 20 at its ~;
upper end for receiving sealant material in bulk form. Slightly below
opening 20 there is provided a heated support member 22 for receiving
and preheating the sealant material 24 in its bulk form. Preferably,
support member 22 is in the form of a heated grid for supporting the
hardened sealant until it is preheat0d to a fluid state and
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flows into the bottom of the feed chamber. An outlet 30 is pro~
vided in the bottom of the feed chamber for dispensing the seal-
ant material.
Disposed in the bottom of the feed chamber is a rotat~
able screw conveyor 26 for supplying the fluid sealant material
28 to the pump 46. Pump 46 operates to force the sealant material
under pressure into heated hose 12. Pump 46 is a positive dis-
placement pump of the progessing cavity type and is of a conven-
tional nature, commonly referred to as a Moyno pump. It will
pump highly viscous fluids, such as the fluid sealant material
described herein. The pump includes rotor-stator elements for
pumping so that as the rotor 46a turns within the stator 46b,
cavities 46c are formed which progress toward the discharge end
o~ the pump carrying the mat~rial being handled uni~ormly and
without pulsation or agitation.
The drive means 18 operates to drive rotatable screw
conveyor 26 and pump 46 and includes a pulley 32 for driving the
common shaft 26a of rotatable screw 26 and pump 46, a drive belt
34 for driving pulley 32, a motor 36 and a drive pulley 38 for
~.
imparting rotation to drive belt 34. As a result, drive arrange-
ment 18, including motor 36, operates to continuously drive screw
26 and pump 46 for ~orcing the fluid sealant material 28 under
pressure through heated hose 12 to handgun 14. A T-connector 48
is provided for connecting pump 46 to heated hose 12 and feedback
; arrangement 50. As shown most clearly in Figure 1, feed chamber
10 also includes heating means 40 disposed on the outer walls of
the feed chamber for further heating the bulk sealant material 24
preheated by heated grid 22 to a fluid state having a pumpable
viscosity. The heating means 40 include separate heating elements ~ ;
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~2 connected by wires 44. Preferably, heating elements extend
about feed chamber 10 on each side wall lOa thereof. i:
The feedback arrangement 50 of the present invention
includes a pressure valve 52 connected by a feedback pipe 54 ~;
to T-connector 48, a feedback pipe 56, and an inlet port 58
formed on the end wall lOb of feed chamber 10. Pressure valve
`~,
~ 52 includes a set screw 60 for setting the desired pressure value
in the system. In operation, pump 46 continually forces fluid :
sealant 28 under pressure into heated hose 12, and if pressure
gun 14 is not operated for a short period of time, the pressure ~: i
may build up to an undesired level. Accordingly, when the set ~; ;
pressure level of valve 52 is exceeded, pressure valve 52 will ~ :
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~ open and allow the fluid sealant material 28 to be returned through
~ .
feedback pipe 56 and inlet port 58 to eed chamber 10. There~ore,
the ~eedback arrangement of the present invention provides a con~
tinuous arrangement for recirculating the fluid sealant material
which is under pressure, and for allowing the pressure value in
the system to be set at any desired predetermined level, and for : :
the system to be maintained by the feedback arrangement 50 at
the preset pressure, and thereby allow intermittent use of the
handgun 14 by the operator. :
As shown diagrammatically in Figure 3, heated hose
12 is connected between pump 46 and handgun 14 for receiving
fluid sealant material dispensed from the feed chamber. The -: :
heated hose 12 is surrounded with a heating coil 12a for maint~
taining the sealant material passing therethrough in a fluid
state. Heated hose 12 further includes a heat sensor, such as a
thermistor, for controlling the temperature in the hose, a thermo- :
stat override as a safety feature which operates to shut off the
supply of heat to heating coil 12a at a present maximum temperature,
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and a thermocouple connected to control box 16 for reading the tempera-
ture level in hose 12.
~ landgun 14 includes a swivel connection 62 for supplying the
fluid sealant material to a chamber 64 formed in the handgun. The
handgun 14 also includes a trigger-operated handle 66 which is spring
biased between its operative and inoperati~e position by biasing means
68. A stop 69 is also provided to ad~ust the movement of handle 66,
thereby to control the rate of flow of sealant material. The output
means 70 of pressure gun 14 includes a noz~le 72 for applying the fluid ~;
sealant material onto a suitable work surface. Nozzle 72, shown in
detail in Figure 4, is removable from the output means 70 of the pres-
sure gun and includes an extruding tip 74 having holes 76 formed therein
for extruding the sealant material onto the work surface. As noted, `
nozzle 72 is removable from handgun 14 so that lt may be interchanged
wlth other size nozzles having different size extruding holes for varying
the rate of flow of the sealant material, as well as the width or con-
figuration of the strip of sealant material which is applied to the work
; surface. `
As noted above, it is an important feature of an aspect of the
present invention to maintain the fluid sealant material passing there-
through at a predetermined temperature level so that the sealant material
has a pumpable viscosity and so that it will not harden to clog up the
system. In this regard, various heating rings or heating elements are
provided throughout the system in addition to heating elements 42 pro-
vided on the outer walls of feed chamber 10 and heating coil 12a surroun-
ding heated hose 12. The additional heating means include a heating ring ;~
80 surrounding pump 46, and heating rings 82, 84 surrounding feedback
pipes 54, 56, respectively. In this manner, the sealant material, as it
is passing through the system, is always being heated to maintain the
sealant material in a fluid state and at a predetermined temperature
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level. Preferably, a suit ~ ~eBh ~ g ring 86 i9 also applied to the
output means 70 of handgun 14 to maintain the sealant material at its
proper temeprature level even when it is in handgun 14.
Turning now to Flgure 3, there is shown control box 16 for
controlling heating elements 12a, 42, 80, 82, 84 and 86. Temperature -~
controller g2 controls the temperature level of heating elements 42 and ;~ ~-
heating elements 80~ 82 and 84, while temperature controller 94 controls
the temperature level of heated hose coil 12a and heating ring 86.
Selector switch 96 is provided to switch bet~een temperature controllers
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10 92, 94 to read the temperature of feed chamber 10 or heated hose 12 on
gauge 100. However, it should also be understood that depending on the
type of sealant mater~al being employed, the present system will operate
to heat the sealant material to a predetermined temperature level any-
where in the range of approximately 150F. to 500F. Control box 16
also includes a switch 98 for turning on motor 36 to supply power to
drive belt arrangement 18, rotatable acrew 26, and pump 46. In this r
regard, it h~s al80 been found to be desirable to energi~e the heatlng
elements before the rotatable screw~conveyor 26 1s operated to ensure
that there is sufficient fluid sealant material contained in the feed
chamber 10. In an aspect of the present invention, rotatable screw con-
veyor 26 and pump 46 can be driven at any desired speed to maintain a
pressure level in the system anywhere in the range oP approximately
200 pounds psi to 500 pounds psi. It should also be pointed out that
depending on the speclfic nozzle 72 being employed on handgun 14, that
the rate of sealant extrusion may be anywhere in the range of 16 to
20 ounces per minute.
In view of the foregoing, it should be clear that the sealant
applicator of aspects of the present invention is not only portable,
but is also capable of receiving sealant material 24 in cheaper bulk
form and heating it to its fluld or flowable state. This provides a ;
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great savings in the cost of sealant employed in the system. In addi-
tion, the portable sealant applicator of aspects of the present invention
operates under a range of high pressure to vary the rate of sealant
extrusion. Moreover, the handgun 14 used in the sealant applicator of
an aspect of the present invention is llght in weight and simple for a ~ ;
single operator to manipulate, and to line uy properly with the working
surface to which the sealant is to be applied. Finally, the portable
sealant applicator Qf aspects of the present invention may be employed
at high-production facilities, since the feed chamber 10 is capable of
holding a relatively large quantity of sealant material. ~ ;
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