Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
PR~HEATERS FOR GI,ASS CONTAINERS
2 The present invention relaxes to a preheating apparatus
J or preheating glass containers to condition them for having
heat shrinkable plastic sleeves applied thereto.
6 BACKGROUND OF THE INVENTION
In the production of glass containers having plastic
hea shrunk sleeves thereon, it i5 common practice to provide
8 machinery which will make a su¢ces~ion of cylindrical sleeves
9 on one part of the machine from lengths cut from a roll
lo supply of shrinkable, predecorated plastic web material.
11 On another part of the machine, bottles or containers are
12 loaded at spaced centers on a carriage which comprises a
18 plurality of neck-gripping chucks on an endless chain of
14 the elongated caxxiage. The bottles carried by the carriaga
16 move through an arc of a circle, at which time sleeves are
18 telescoped from lower, sleeve-forming mandrels onto the
containers positioned thereabove. Once the sleeves are
18 positioned on the containers, the containers and sleeves
13 are moved through a linear shrink tunnel or oven, while being
20 simultaneously rotated by mechanism engaging the chucks holding
21 the bottles.
22 It has been found in this process that it is necessary
2~ to have heated containers which either contain the heat of
24 formation from the glass-forming process or are preheated in
2~ some fashion by a preheating oven. These preheat ovens in
26 the past have been of the radiant energy type, either gas or
27 elsctric. In configuration, they have been in the form of
28 an elongated tunnel through which the chucks that hold the
29 containers will be moved in series through a gap between
80 opposed heat-radiating surfaces. Radiant heaters of the
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1 gas type typically provide burners which impinge on or heat
2 ceramics that in turn actually radiate the infrared radiation
outward toward the containers with applied sleeves that are
4 being moved through the elongated oven. The length of the
6 pre-oven is selected, depending upon the amount of heat to
6 be supplied to the containers, to elevate them to a suitable
7 sleeve~accepting tempçrature and to the speed with which it
8 is desired to operate the sleeving machine.
The preheated container is believed necessary because
10 of the inherent heat shrinking characteristics of the plastic
11 sleeve. The heat that would normally shrink the plastic
12 sleeve about the container is txansferred from the heated
18 sleeve to the cooled container and results in an uneven
14 5hrinkage of the sleeve on the container. To avoid this
16 uneven shrinkage and resultant wrinkling of the plastic sleeve
lB material, it is found necessary to have the container at a
t7 somewhat elevated temperature in the neighborhood of 100-150F.
18 so that it will not become a heat sink for the radiation
19 being ab~orb~d by the sleeve duxing the shrinking process.
80 Thus, it can be seen that it is necessary to have a preheating
21 arrangement for the glass containers prior to their being
22 introduced into the sleeving machine.
28 One serious drawback with the preheating ovens used in
8~ the past has been the requirement that, in the event the
2~ sleeve-applying machine breaks down and there is a supply
2~ of mottles within the length of the preheat oven, it it
27 necessary that the containers be moved out of the oven.
28 The radiant energy type preheaters have a great deal of
2~ heated surfaces therein which radiate for a considerable
Jo period of time even after they are shut down so that unless
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1 the containers are moved quickly out of the oven they can
2 become overheated. This great amount of excess heat,which
8 would distort and overheat the containers if the bottle-
handling equipment were stopped, is a serious and important
considexation. In the situation where a stoppage of the
sleeving machine is necessary, and since the containers are
held by their neck and are already carried by the chucks
8 that will move them through the entire cycle of the machine
operationl it is necessary to continue to xun toe machine
lo through a long cycle to clear the bottles from the machine.
11 Obviously, these bottles will have to be stored somewhere
12 because they will not have had sleeves placed thereon.
18 They may even have been subjected to heat in the shrinking
14 oven.
16
The present invention is directed to providing a bottle
g preheat oven wherein the bottles that are to be preheated
18 are conveyed through the oven on an open weave, articulated
19 link-type conveying belt. A pair of parallel, elongated
20 gas burners extend essentially the full length of the preheat
2~ oven and flames from these burners are directed toward the
28 opposed sides of the bottles which are positioned on the
2~ conveyor. The f lames issuing from the two burners on opposite
2~ sides of the moving containers will have their flames Lmpinge
26 on the sides of the container as they are moved on the moving
2~ belt conveyor. A third burner generally coextensive with
2q other burners and beneath the convayor will impinge its
28 flames on the bottom of the bottles as well. In this manner,
29 the bottles may be preheated by f lame impingement In the
80 event of a breakdown, so that the requirement for heated
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1 bottles is o~via~ed, the burners may be shut off and the
2 conveyor stopped with the bottles rem ining within the confines
of the oven without damage thereto.
It is, therefore, an object of the present invention to
C provide a preheat oven which may be shut down without requiring
that the containers within the oven be moved out of the ovenO
7 BRIEF DESCRIPTION OF TOE DRaWINGS
8 FIG. 1 is a side elevational view of the apparatus of
the invention; O
FIG. 2 is an end view of the apparatus of Fig. l looking
11 in the direction of arrow 2 on Fig. l; and
12 FIG. 3 is a perspective view, on an enlarged scale,
18 of the burners used.
14 DETAILED DESCRIPTION OF TOE DRAWINGS
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16 With particular reference to Figs. l and 2, the preheat
l oven of the invention will be described.
Iq A rectangular frame including a pair of elongated channel
l8 beams 10 extend beneath and along the length of the apparatus
l serves as the base. Serving as side frames and extending up
20 from the base are a plurality of vertical beams ll. The
21 beams 11, along with horizontal upper frame beams 12 and
22 the base 10, provide a generally rectangular elongated
28 framework. A pair of opposed horizontally-extending conveyor
2~ supporting tracks 13 extend the ull length of the frame and
26 serve to support and guide a conveyor 14. The conveyor 14
2B is an open weave metal, chain-link-type conveyor which
2q extends through the framework from end to end at an elevated
28 position, approximately half the height of the vertical
2~ beams 11. Thus, it can be seen that the tracks 13 serve to
80 guide the conveyor 14 through the length of the apparatus.
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1 Extending substantially the full length of the preheat
2 oven, and in alignment beneath the conveyor 14, is an
8 elongated gas burner 15. The burner 15 is in the form of an
elongated pipe having a plurality o burner openings in the
upper surface thereof directed toward the bottom of the
conveyor 14. The burner 15 is supported at its opposite
q ends by brackets 16 and held in p.Lace on the brackets by
8 U-bolts 170 The b.rackets 16 are supported at an elevated
9 position by vertical posts 18 and 19. In addition to support-
ing the brackets 16, the posts 18 and 19 serve to support
11 inwardly-extending brackets 20 and 21~ The brackets 20 and
12 21 serve to support a pair of horizontally-extending, elongated
burners 2~ and 23. The burners 22 and 23 extend along
14 opposite sides of the conveyor 14 at a somewhat elevated
16 position relative thereto. These burners hava openings at
the lower edge facing generally toward each other and toward
iq the center of the conveyor 14.
18 A best shown in Fig. 2, flames which will issue from
19 the ignition of the gas coming from the burners 22 and 23
20 will impinge on the sides of containers which are being moved
21 through the oven on the moving conveyor 14. The frame 12
22 above the run of the containers is provided with a top 24.
28 The sides of the frame are closed down to the helght of the
24 conveyor brackets or tracks 13. The side of the oven,
26 as best seen in Fig. 1, is closed in by a series of doors 25.
2~ These doors are hinged a their upper edge by hinges 26 fixed
27 to the side of the oven. These doors are provided adjacent
2~ the center thereof with transparent glass panes 27. The
2~ panes or windows 27 provide viewing ports to observe the
80 proper combustion and operation of the burners and the
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1 impingement of the flames from the burners on the containers
2 as they pass through the oven.
8 the doors 25 are also provided with handles 30 which
serve as a convenient mechanism for opening and, if necessary,
provide access to the interior of the oven. Above the con-
a tainers, the entire upper area of the oven below to top 24
serves as a plenum chamber which is connected to the inle' 28
8 of an exhaust fan 29 mounted on the top of the oxen. Operation.
9 of the exhaust fan ~9 serves to carry fumes away prom the
10 oven and at the same time will insure that the heat produced
11 by flame impingement will be of a predetexmined heat input
12 to the glass containers. In ordar to control to some extent
18 the exhaust and the degree of movement of air upwardly out
of the oven through the exhaust fan 29, a series of adjustable
16 louvers 31 are provided between the burner chambers and the
ld upper plenum chamber.
q The detail of the burners, separate from the oven, is
18 shown in Fig. 3. Each of the burners 15, 22 and 23 have a
19 gas supply line 35 connected to a cone-shaped inlet and air
20 mixing connection 36. Atop each of the burners is mounted a
l ~emp~rature sensox 37 and pilot burner 38. The sensor 37 is
22 in the flame produced by the pilot burner 38 and thus is a
2~ part of a safety system for shutting off the gas to an indi-
24 vidual burner in the event the pilot flame i5 not functioning.
2~ It should be noted that the burner openings 39 in the burner 22
26 begin in a line directly beneath the pilot burner and, in
2q fat the pilot burner flame is configured to sweep over
28~several of these openings 39. The openings then continue in
2~ a row over the corner of the square burner to a long line
80 that extends along the lower inner corner of the burner.
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1 This row of opanings is slightly above the level of the
conveyor surface so that flames from the burner will be
8 directed outward to impinge on th0 bottles. The exhaust
fan 29 will cxeate an upward draft that causes the flames to
6 bend upward along the sides of the bottles.
The center burner 15 has a pair of rows of burner
7 openings in its top surface so that the flames therefrom
8 will impinge on the bottom of the containers through the
openings in the conveyor structure.
The temperature sensors may be connected to solenoid
11 valves in the gas supply lines for shutting off the gas in
12 the event the pilot burners are out.
18 With the apparatus as described, it can be seen that
14 glass containers which are to be preheated are moved in the
16 direction of the arrow shown in Fig. l by the conveyor through
lff the oven where they are heated by flame impingement directly
7 onto the container. This flame impingement, while serving
18 to heat the containers, also has in some instances a salutory
l effect of cleaning any residue from the containers which
80 might have been placed thereon during the worming cycle
2~ through inadvertence.
22 In the event it is necessary to stop the mvvement of
2~ heaved containers to the previously described sleeve-applying
84 machlne, it is only necessary to signal back to the burners
2~ and the burners may automatically shut off. At the same
2~ time, the conveyor 14 will be stopped and the containers may
27 remain in the position in the oven that they have assumed.
28 it this time, the fan may or may not be shut down, depending
29 upon whether it is desired to cool the containers or whether
80 it is desired to let the containers retain the heat that they
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1 have already absorbed. However, when the burners are shut
2 off, it is not necessary in the present preheat oven that the
containers be removed therefrom as is the case in those
I- infrared type heaters used in the prior art. Infrared heaters
s produce a great deal of radiation even after the source of
fuel is shut of. In the instance of the infrared type gas
heaters, it is necessary to move the containers out of the
8 preheater or stand a chance of damaging the containers. It
9 is particularly significant in the event the system for
conveying the containers through the preheat oven fails and
11 some containers are left positioned within the oven. In the
l prior art, it was necessary to provide for some moans of moving
18 the conveyor to get the containers out of the preheat oven
l In the present case, regardless of whether the conveyor is
16 running or not, the cutting off or shutting down of the
l burners is all that is necessary to interupt the low of
heated containers through the oven, and the containers may
18 remain within the oven once the gas is turned off without
~9 any problem relative to overheating.
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