US2408447A - Apparatus for sealing containers - Google Patents

Description

Oct. 1, 1946. RAU

APPARATUS FOR SEALING CONTAINER'S Filed Dec. 27, 1940 5 Sheefs-Sheet l Oct. 1,1946.

H. A. RAU 2,408,447

APPARATUS FOR SEALING CONTAINERS Filed necfzv, 1940 5 Sheets-Sheet 2 I I .136 I Z23 {Q .2 7 16 J30 Z9 H i|l||| u i m l .2125 16w g 126a m1 Ill h fir I II I H l ""3 1h? "Kim: I 'Hml/ .114 'lzf Oct. 1, 1946. A RAU .APPARATUS FOR SEALING CONTAINERS Filed Dec. 27, 1940 5 Sheets-Sheet 3 oat. 1, 194 A, AU 2,408,447

APPARATUS FOR SEAL ING CONTAINERS Filed Dec. 27, i940 5 Sheets-Sheet4 Z I/ Z Elmo/14M Ear-77 A u- Oct. 1, 1946. H. A. RAU

I APPARATUS FOR SEALING CONTAINERS Filed Dec; 27, 1940 5 Sheets-Sheet 5 M. Mm

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Patented Oct. 1, 1946 UNITED STATES PATENT OFFICE Harry A. Rau, Baltimore,

Cork & Seal Company,, lnc., Baltimore, Md., a corporation of New York Application December. 27, 1940, Serial No. 371,961

The present invention relates to an appa for sealing containers.

An important object of the'invention is to provide an efiicient apparatus whereby a cap or other closure may be applied to a container in the presence of steam or other expanded fluid so of moisture in the container.

It has been found that one reason for lack of uniformity in the low pressure effect obtained by prior methods and apparatus is the fact that drafts moving through cause the temperature ofthe steam to be reduced. Naturally, if the temperature of the steam is reduced, the vacuum effect will likewise be reduced. Also, reduction of the temperature of the steam while uncapped containers-are moving through it enables particles of condensed moisture to fall upon the container contents.

the usual steam tunnel Md., assignor to Crown 1 2 Claims. (Cl. 226-82) I theoretically correct direction of jetting will pro- The presence of such moisture is very harmful to numerous products.

Drafts are created within prior apparatus because such apparatus have relied upon jets of steam to create a steam atmos phere within the tunnel. It is found that these incoming jets, by an' injector effect, serve to the steam tunnels of draw air into the steam tunnel with an immediate cooling of the jetting steam. In an effort to counteract incoming air and establish a high temperature within the steam chamber adjacent the point of application and sealing of caps, the

V steam tunnels have been made relatively long with a view of isolating the cap applying chute and the sealing means from the ends of the tun-' nels. However, these'modifications have nothad the desired result. y

In more recent developments of the steam'jet ting methods, the concentration f jets atjthe cap applying and sealing point has been increased, and the direction of jetting "carefully regulated. These systems havefproceededon the the top wall of the tunnel fairly close to the instead, results in aggravating the increased injector effect.

vide high temperature steam at such point.

However, concentration of jets, regardless of direction, in no way prevents draft effects but, drafts because of I have found that if prior commercial methods are entirely discarded and steam is delivered to the tunnel at an extremely low pressure and with no jetting action whatever, a quiet body of steam at high temperature will be maintained in the tunnel with no inducing of drafts. Because of the high temperature thus maintained in the tunnel, even the head space of a container with its contents entirely at room temperature is quickly brought to a sufficiently high temperature that no condensation can form in the head space and all air within the head space is quickly replaced by steam at high temperature. Furthermore; because a high temperature can quickly be imparted to a container and all air driven from its head space, there is no necessity for providing the long tunnel heretofore regarded as essential.

Use of low pressure steam, as contemplated by the present invention, is economical in that a large steam boiler is not required. Prior developments have invariably flowed the steam horizontally into the tunnel, usually by jets positioned in planes adjacent the mouths of the containers. As has been hereinbefore stated, the use of jets has the effect of drawing air into the steam tunnel. Furthermore, if the jetsare arranged in the manner just described, this incoming air formsa blanket at the top portion of the tunnel above the steam jets. As a result, the temperature of the tunnel is lowered because this blanket of air can constantly move through the tunnel above the jets.

In aneffort to combat the above difiiculty, recent developments have included a steam jacket above the tunnel, the top wall of the tunnel serving as the lower wall of the steam jacket and the purpose being to thoroughly heat the extreme upper portion of the tunnel interior. Such an arrangement does not overcomev jetinduced drafts and I have found that the provision of a steam jacket is altogether unnecessary if the steam is so flowed into the tunnel that it may freely rise. It is also desirable to have mouths of the'containers. With the top wall at such point and with the steam entering without force at. a point below the mouths of the con presumably reasonable ground'that an increase in the number of jetsv at thecriticaland a tainers and enabled to rise, there is no Possibility 3 of a superimposed layer or stream of air within the tunnel.

Furthermore, the use of slowly rising low pressure steam avoids the Waste which occurs when pressure jetted steam is used, most of the pressure jetted steam being blown almost directly from the tunnel.

Another object of the invention is to provide a container sealing apparatus which will occupy a minimum of floor space.

Prior container sealing apparatus, and particularly those which include a steam chamber, oc cupy a comparatively long area. As hereinbefore indicated, one purpose in providing a long steam tunnel has been to form a long enclosed area at each end of the critical cap applying and sealing points, with a view. of isolating these points from outside air and obtaining high tem-. With jetting,

perature at least at such points. the length of the tunnel in no way counteracts drafts. Some types of such apparatus have been provided with capping elements of endless type and it has been thought desirable to have at least a substantial portion of the same enclosed by the tunnel, particularly since the element might induce drafts in the upper portion of the tunnel. By the present invention, a long tunnel is not necessary to obtain a high temperature adjacent the cap applying and sealing means and since the use of a longitudinally moving sealing element preferably is avoided, the tunnel need not be extended to enclose such a device.

Use of a short tunnel, with its lower portion clear of steam, permits each container to be constantly visible. This is a highly desirable feature particularly during the initial portion of a run when it is necessary to ascertain whether the cap applying and sealing adjustments are correct.

The principal purpose of providing a lengthwise moving capping element has apparently been to enable the containers to move continuously during the sealing operation. While this procedure theoretically gives high production, the sealing action afforded thereby is not always satisfactory, particiuarly when handling caps provided with holding lugs upon their skirts. Also, containers may be upset or any type of cap may be bent or dislodged when it first comes into contact with the sealing element as well as when it finally moves out of contact with the element. This is particularly true if there is the slightest slippage of the upper capping belt with respect to the lower container supporting belt, or if the container slips with regard to either belt.

I have found that a high rate of production with completely uniform sealing can be obtained by stopping the containers in order to seal the same. The high rate of satisfactory production obtained is due to the fact that there is less likelihood of containers being upset during the seal ing action, with resultant long stoppages to clear out the spilled contents, and also because no containers need be discarded and returned through the machine because of improperly applied caps. At the same time, the arrangement of the present invention occupies a minimum floor space. It is also to be noted that the use of a sealing head of non-continuous type contributes to a more efficient and uniform vacuum elfect within the containers because of certain factors hereinafter-discussed in connection with the operation of the device.

Another object of the invention is 0, provide a capping element which is particularly adapted for the quick and proper sealing of containers.

A further object of the invention is to provide a control for a capping mechanism which is actuated by contact of a container therewith. Such an arrangement is highly desirable because it eliminates the necessity of moving containers through the machine in carefully spaced relation.

Another object of the invention is to provide a container actuated capping control of such design as to insure that the container will be stationary when the sealing is performed, thereby making it certain that every type of cap will be properly sealed and not damaged and that a high not rate of production will be obtained.

One reason why container sealing machines of the present type have hereto-fore been provided with continuously moving sealing elements was because it was thought that any stoppage of the containers to seal the same might cause the containers to be upset, or their contents to be so disturbed that some portion thereof would be spilled. It has been found that the present invention, involving moving the container onto a stationary support while its upper portion is gripped, prevents upsetting and causes no spilling of containers filled to the customary levels. Also, by stopping the containers to seal the same, all of the disadvantages of a continuously movable sealing element are eliminated and every type of cap can be efiiciently sealed upon containers. As has been stated above, the continuous system is only efficiently applicable with certain types of caps.

Still another object of the invention is to provide a container holdingand centering arrangement which is adapted to engage the containers while caps are being applied thereto As has been hereinbefore indicated, considerable difficulty has been experienced in prior capping machines because containers were frequently upset upon contact with the cap applying device. By the present invention, the containers are securely held at the time that they come into contact with the cap applying mechanism, all possibility of the containers falling over being thereby eliminated.

Another object of the invention is to provide a holding mechanism which is simple in construction, will smoothly and efficiently engage and center containers, and which is readily a justable for containers of various sizes and shapes.

Another object of the invention is to provide a cap applying and sealing arrangement which includes means to properly level caps upon containers immediately prior to the sealing action.

Other objects and advantages of the invention will be apparent from the following drawings, wherein:

Figure 1 is a side elevation of the apparatus included in the present invention;

Figure 2 is a detail view showing a sealing head control mechanism;

Figure 3 is a side elevation of the central portion of the apparatus, with parts broken away;

Figure 4 is an elevation 'of the outfeed end of the apparatus;

Figure 5 is atransverse vertical sectional view on the line 5-5 of Figure 6;

Figure 6 is a horizontal sectional view on the line GB of Figure 4;

Figure 7 is a horizontal sectional view on the line 'l'! of Figure 3;

Figure 8 is a transverse vertical section through Y the capping head operating link;

outfeed end of the tunnel.

tact with the belts of a device I! so that the container will be held upright. The belts of device :speed as conveyor H. "the leading edge of the mouth of the container will contact with the lowermost cap. in a cap chute or cap applying means 'ing movement of thecontainer will cause this cap to be withdrawn from :a loose position upon the mouth of the container. -Chute I8 is enclosed "trical heating element to insure that caps will be brought to a sufficient temperature to prevent :steam from condensing upon them before enter- :ing the chamber I2.

:moved from the chute :come into contact with in Figure 11. :nally completed, by which time Figure 9 is a front .view of a preferred form of sealing head control mechanism; Figure 10 is a vertical sectional view line lo -I of Figure 9; and

Figure 11 is a diagrammatic view of the control wiring of the apparatus. The construction of the present apparatus and its operation may be generally described as fol: lows? The numeral Ill designates the table-of the machine along which moves a continuously moving endless conveyor II. A chamber or tunnel 12 extends above the table 10 and a steam atmosphere is maintained therein by steam flowing from a supply duct 13. Steam under low pressurev issupplied to the duct lit by an inlet pipe l4, the-steam passing up through the duct to issuefrom its wide-mouthed open end with no .jetting action.. In order to insure that. any force behind the steam will be substantially eliminated, the steam rising in duct [3 passesthrough one or more fine mesh wire screens indicated atv 16. If more than one screen is used, they'ar spaced a substantial distance apart as shown in Figure 3. A hood l at the upper end of duct 13 permits the steam to move upwardly and longitudinally with respect to the steam tunnel l2 to form a cloud of steam at approximately atmospheric pressure in the upper portion of the tunnel.

Containers moving through the apparatus enter at the left hand end (Figures 1 and 3) upon the endless belt II and are conducted past the hooded steam duct l3 into the steam cloud or atmosphere which exists in the upper portion of the tunnel from a point alongside the duct to the As a container moves past the duct its upper portion comes into conholding and centering (in the ll'move at the same Immediately thereafter l8 and the continuthe chute and drop to and may include an elec- As soon as the cap has been substantially rel8, its upper portion will the forward edge of a :plate 19 resiliently mounted upon and forming part of the capping plate or member 20 and plate 19 will level the cap up While the above leveling action is taking place, the container base will be moving onto a fixed supporting plate 21 and its lowerportion'will come into contact with a trip device 22. As the movement of the container with conveyor II and holding device l1 continues, the container will force thetrip device laterally out of its path. As the'forward movement of the container stops,

because its base has moved entirely oif conveyor H; and will stand entirely upon plate 2| as indiandalso because dicated at A in Figure 6, has

't control- (Figure 9) to actuate the delayed action electrical circuit diagrammatically shown When the Figure all movement of the container will have stopped, the electromagnetindicated at 24 will .be energized, so that the capping plate 20 will move downwardlyto compress the light springs above plate I9 and posi-- tively force position upon the stationary container. The: circuit of the capping member 20 will be broken when the latter has moved downthe proper dis tance and itwill immediately rise so as to leave the container standing free upon the fixed plate:- 21. Contact of a succeeding container with the container standing at A will push the latter offi plate 2| and upon the outfeed portion of. endless conveyor I I. It will be noted from Figure 3 that; the upper run of conveyor ll dips down beneath. the stationary plate or support 2 I.

It will be understood that during the movement of the container through the steam chamber l2 and before a cap is applied thereto the head; space of the container will be filled with steam. from the cloud present in the upper portion of. the steam chamber l2 and steam will be entrapped in the head space when the container is: capped or sealed. As the sealed container moves from the steam chamber through a gradually dissipating cloud of steam, the steam in its head space will condense to create a low pressure condition therein.

Referring to the apparatus in detail, the table Ill is supported upon legs 30 which also support the usual tray 3! immediately below the table. The upper surface 3201 table it is cut away to provide a space in which the upper run of the conveyor ll may move and conveyor ii is preferably cf wire mesh andrnoves about pulleys 33 and t4 journaled at the ends of the table l8. Pulley 33 is fixed to a shaft 35driven from a shaft 36 by means of a sprocket'chain 3'5, Shaft 3'5 is in turn driven through a chain 38 from a shaft- 39. A motor including a speed reducing mechanism drives the shaft 39 through a sprocket chain A i.

In order to maintain containers in line, guide strips 42 are provided with rearwardly extendplate on the container mouth.

ing pins 43 hich extend through posts A l fixed to table !0. These strips are adjustable for different size containers and are preferably spring mounted by means of springs 44a surrounding the pins 43. i I

As best shown in Figure 3, at a point near the outfeed end of the'steam chamber 12 the upper run of the container supporting conveyor H is guided downwardly about a roller 45 over guide rollers 46 and 4'! (Figure l) and the supporting- 2| fixed to table H) bridges the gap thus: provided in the upper run of the conveyor.

The steam chamber l2 includes side walls 5i! and 5| and a top wall 52. Each side wall 5| and. .52 has a toothed rack 53 fixed to its vertical edges, which racks are engaged by pini to shafts 55 journaled in the side walls otthe table Hl so that rotation of the shafts 55 "will cause the steam chamber to be either raised or lowered with respect to the table it and the con-- 5 tainer supporting conveyor I l. The shafts 55 have ste 11 'circuit'isfis tudinally adjustable with resp wormfgears secured thereto engaged by worm. wheels on a longitudinal shaft 56 and shaft 56 is: suitably geared to a shaft provided with a handle .S'Ladapted tocontrol the lifting or lowering of am chamber l2. The steam chamber is held in adjusted position by means of locking nutsor hand wheels 60 on the shafts 55 which bear against the sides of the table Ill.

The top wall--52 of the steam chamber is ect to the side walls longi-v and since itsupportsthecap applying chute i8 and capp'ingmechanism 20, the position of these devices with respect to the stationary supporting plate 2| may thereby be adjusted longitudinally racks 65 formed on the upperedges of the side walls 59 and 58. The top wall 52 may be locked in adjusted position by means of nuts 63 threaded on bolts extending through longitudinal slots 69 in the side walls and thence into the top wall 52. As best shown in Figure 5, the top wall 52 is closely fitted with respect to the side walls and is supported. by the ledges 52c shown in Figure 5.

The holding and centering device ll comprises an upper and a lower endless belt ll on each side of the endless conveyor. supported in a U-shaped bracket '52 (Figures 4 to 6) which includes two outwardly extending pins 73 and it. The pin it is slidable in a bore in a plate i5, secured against a large rectangular opening it in the corresponding side wall of the steam chamber. The other pin 14 is slidable in the bore of a sleeve ll threaded in the plate 15. As shown in Figure 6, the inner end of each sleeve H is counter-bored and a coil spring 18 surrounding pin i l seats in this counter-bore. The

position ofeach bracket 72 with respect to the center line of the container supporting conveyor H may be adjusted inwardly by rotation of the hand wheel 79 fixed to each threaded sleeve 1?, since the sleeve will act upon the coil spring 78 to force the bracket inwardly by a straight line or rectilinear movement. The brackets can be moved outwardly by pressure upon the same and because of their resilient mounting, will accommodate themselves to variations in containers. As best indicated in Figure 1, the hand wheel 19 of each upper centering device is longitudinally reversed with respect to the position of the corresponding element of each lower centering device.

The holding and centering devices may be adjusted longitudinally of the machine by releasing the bolts 8i? (Figure l) which extend through slots to hold the plates to the side walls of the chamber l2.

Each U-shaped bracket 72 includes a rear wall 85, a lower wall 86 and an upper wall 8?. As shown at the bottom of Figure 6, each lower wall 86 is cut away at its infeed end. The outfeed end of each bracket has iournaled therein a vertical shaft 98 to which is fixed, between the upper and lower plates 33 and 81, a pulley 9|. An idler pulley 92 is supported on a stud 93 at the infeed end of each bracket and the belts H move about these pairs of pulleys. The inner run of each belt H is supported or held inwardly with respect to the center line of the machine by small idler rolls 96 positioned in the brackets 12. As best illustrated in Figure 6, the series of rolls 94 does not extend entirely to the infeed end of a bracket 12 and because of this, as well as because of the fact that the infeed end pulley 92 is of reduced diameter, each belt "H will have the infeed portion of its inner run slightly inclined so as to assist in the centering action of containers. However, it will be noted that the remaining portion of the inner run of each holding b 1tis positively held straight by the small rolls so that a uniform pressure will be applied to containers during their movement with such portion ofthe belts.

It will likewise be noted that each belt H and its supporting bracket 12 is resiliently mounted, as an entirety, for inward and outward movement. That is, as a container causes the holding belt to be forced outwardly to a slight extent through the side wall of the steam tunnel, that holding belt and its supporting bracket 12 will move bodily outwardly along 'a, straight line and with no swinging movement.

As best shown in Figures 3, 4 and 6, each shaft 99 carrying a driven pulley 9| of a' holding device has a sprocket wheel 98 fixed thereto which is engaged by'a sprocket chain 99 extending from the outfeed end'of the steam tunneland about a large sprocket wheel I00 fixed to a vertical shaft IUI journaled in brackets l02' extending from the upper portion of'th'e side walls of'the' steam chamber. As best shown in Figure 1, the two holding belts at each side of the steam chamber are both driven from the corresponding vertical shaft I131. The lower portion'of each'vertical shaft it! is slidab-lyjournaled in brackets '33 fixed to the' side wall of the table I!) and a beveled gear "i4 is keyed to the shaft liH-between these brackets." Beveled gear H34 meshes with a beveled gear I05 fixed to the shaft 39;

It will be noted that the shafts llll may move vertically with the steam chamber without af-- fecting the driving connection with thebeveled gears I04.

As illustrated in Figure 6, the sprocket chains 99 which serve todrive the holding brackets 12 may be held-under proper tension by a roll [10' resiliently supportedfrom the brackets I02.

The cap supply and applying chute" l8 preferably comprises two' spaced guideways H5, each of wellknown angular form to provide a shelf to supportone' edge of the cap and "a shoulder to guide the cap. The major portion of the'chute is surrounded by a casing'which may include an electric heater l8a. The-guideways' in lugs or shoulders which serve to stop the downwardm'ovement of the line of caps. As indicated in Figure '3, the lower portionof the'skirt of the lowermost'cap will bearag'ainst these shoulders with the in termediate unsupported portion ofthe skirt ex'-- tendinginto the path of the lip of an advancing container. the cap over the shoulders I i 6 so that it will drop l [5 terminate to a substantially leveled position on the con:

tainer mouth; thesucceeding cap then dropping down against theshoulders of a cap from its substantially vertical position in the chuteto a substantially horizontal position without sidewise tilt is assisted by roller Ill journaled at the lower end of a weighted plunger 1 IB' slidably mounted in an aperture in the upper wall 52 of thesteam chamber. During its levelingmovement the top'of the cap is'also' continually engaged by the spring plate I9j of the capping device. Plate 19 includes upwardly extending studs H9 which fit in socketsin the capping plate '20 to thereby guide the vertical movement'of' plate l9. Plate 19 is urged to the normal downward limitp'osition illustrated in Figure 3 'by'relat vely light coil springs I20, one of which 'is positioned between each corner of plate l9 and the corresponding corner of the capping 'plate 20. It will be noted that the infeed end of'plate"|9 is beveled to guide the caps beneath'theplate.

lie of well-known form As a result, the containerwilllift I It; The movement the capping plate The above capapplying arrangement including v the roller H1 and plate possibility of the cap dropping from the container.

A particularly desirablefeature is that the cap is firmly held iroin the moment that it leaves the chute 18 until it is finally sealed.-

Referring to Figure 3, the capping member or plate 20 is mounted immediately adjacent-the cap applying pair of rods 7 the top wall of chamber I2. The rods I26 are secured at their upper ends to a bar I21, this portion of each rod being threaded toreceive nuts to bear on the upper and lower surfaces of bar I2! so that its position with respect to the rods can be adjusted. Intermediateits length each-rod I26 is provided with an'adjustable collar Him and a coil spring I28 is positioned between each such collar and the upper wall of the steam chain:

ber; These springs serve to urge the rods and thereby capping plate 20 to an upward position.

A plunger I29 is fixed'to the bar I21 and carries a plate I38 which is urged to an upward position by a coil spring I30.-. The upper surface of plate I38 is adapted to contact with rounddisks I3| pivoted as shown in Figure 8 in a cut-out portion I3|a ofa link 1-32. Plunger I29 extends through the cut-out and between thedisks as shown in Figure 8. The linkI32 has one end I33 to a post I34 and the pivotedas indicated at 7 other end of the link is pivotally connected as Y at I35 to a verticallink I38 pivoted to the armature I31 of electromagnet 24. 7 It will be noted that downward movement of armature I31 will cause the disks I3I toact upon chute I8 and is rigidly fixed to a I26 extending through apertures in v 212 and m.

separated positioni illustrated in Figure 9, this position being controlled by the adjusting screws In the operation of the control mechanism 23, asa container is moved from the infeed portion of supporting' conveyor H to the position on the stationary plate 2| indicated in Figure 7, the forward and lower portion of the containerwill engage the..roller I43 of trip 22 to move the toggle mechanism towards straightened position. As a result, thelong link I will mo veto the rightwith regard to Figure '7, thereby moving the link I48 tothe left in Figure 9.- Such movement of link I48 will carry the block 200 to the 7 left so that the point of pawl 203'w'ill contact with a triangular nub 2 I4 which extends upwardly from the-upper contact blade 288, depressing this plate so asto bring its contact intoengagement with the upwardly facing contact on lower blade 209 to cause a circuit to be actuated as hereinafter described. Rod I43 will continue its movement to the left in Figure 9 so that pawl 203 will continue past the nub 2|4 to permit the blade 203 to rise so that only a momentary electrical current will flow between the contacts carried on the blades. The container will remain in the stationary position indicated in Figure 7 as well as at A in Figure 6 until the succeeding container contacts with it to move it from the stationary plate 2| to the outfeed portion of conveyor-II and the 'pawl 203 will remain on the' left hand side of the nub 214 while the container is in this posispring mounted'plunger I29 and thereby depress serve as a resilient connection to compensate for containers of slightly greater than normal height and the lower springs. I28 will serve to return the capping plate I25.to normal position. I

As shown in Figure '7, he trip 22 for the capping member 20 is of toggle form and comprises a lever I4I pivoted at I42 to the stationary plate 2| and carrying a roller I43 at its free end. Also, the free end of lever. MI is pivotallyeonnected to an arm' I44 pivoted to a long link I45. As shown the device 23. Within the housing, the rod I48 has a block 200 fixed thereto and the rod isurged to the right as Viewed in Figure -9.by a coil spring 20I which surrounds the rod between the far wall I of the housing and block 200. Block 200 carries a swinging pawlj 203' which normally hangs downwardly alongside a vertical shoulder 204 on the block 200 asshoWninFigure 9 and has. its

lower face 205 inclined as indicated in Figure 9. A block of insulating material 206 is positioned in the lower portion of housing I50 by means of screws 201 and a pair of spring blades 208 and- 209 are mounted on upper stepped faces of block 206 by means of screws 2| 0 and 2H, respectively, which also serve as binding posts for the contacts. The spring blades 208 and 209 carry contacts at their free ends and are, normally in the;

I25. The upper spring I30 will I45 in the link. The far end of link i .3 tion. When the container shownin Figure 7 moves to the right to enable the toggle mechanism to resume its normal position in the path of the next container rod I48 will return to the Figure 9 position causing pawl 203 to ride over the nub 2 I4. However, since the right hand face of pawl 203 is inclined and because the pawl is free toswing in a clockwise direction, it will simply ride over nub 2 I4 without depressing the spring blade 208. Hence, the contact element of blade 208 will not come into engagement with the contact of lower blade 209v during return movement. V

Figure 11 showsthe control circuit of the mechanism whereby the closing of the contacts of the device 23 will cause the capping plate 20 to be moved into engagement with a container on the stationary supporting plate '2 I. Referring to Figum 11, it will be noted that the spring blade 208 is connected to a main conductor 225 by alead I 226 while the stationary blade 209 is connected by a lead 22'! tothe coil 228 of a retarded relay, the coil being, connected by a lead 229 to the other main conductor 230. .When the contact of spring blade .208 is moved into engagementwith the, contact of sp ring blade 203, coil 226-wi'l1 be momentarily energized. However, since the relay is of ,the retarded type, it will not move. its armature-23 I into; engagement with contacts 232 and 233 until a fraction of a second has elapsed,

thereby insuring that the movement of the, conthe stationary supporting plate 2| is entirely completed and the container is; entirely stationary before the capping head 20. begins itsdescent. q 1 When-.relay 228 moves its armature 23I to bridge the contacts 232 and 233; it will energize one coil 234 of a'double-acting relay since the contact 233 is connected to'one' side of coil 234 bya lead 235 and the coil" is alsoconnected'by a lead 236 to themain conductor 230. The other contact 232 is connected by a lead231 with the of Figures 9 and 10.

-ver and having its outer end a movable contact 'ment with a fixed spring contact I63. It will be noted fromFigure' 2 that movablecontact I 62 vi 2,-40a447 opposite main conductor 225. This energization of coil 234, which is only momentary, will draw an armature 238 into engagement with fixed contacts 239 and 240 but armature 238 is mechanically interlocked so as to remain in the position to which it is urged. Contact 240 is connected by a lead 24! with main conductor 230 while contact 233 is in circuit through a lead 242 with the coil 243 of the electromagnet 24 of the capping head, this coil being connected at its opposite end by a lead 244 to the main conductor 225. Energization of coil 243 will cause its armature I3'I to be drawn downwardly so that the right hand end (Figure 3) will be drawn downwardlly thereby depressing the capping plate 20. When the right hand portion of link I32 reaches its extreme lower position, it will engage a button 245 forming part of a switch element 246 mounted as illustrated in Figure 3, depressing the button 245 so as to cause the contact carried by the latter into engagement with a fixed contact 246. Moving contact 245 is connected by a lead 247 to the opposite coil 248 of the double-acting and mechanically interlocked relay and this coil is also connected by a lead 249 to the main conductor 230, while the fixed contact 246 is connected by a lead 250 with the opposite main conductor 225. Hence, when link I32 depresses button 245, it will close the circuit just described, so as to energize the coil 248 to thereby return the mechanically interlocked armature 233 of the double-acting relay to the position illustrated in Figure 11, thereby de-energizing the capping head actuating coil 243 so that the springs I23 may return the capping plate 20 and armature I31 to raised position. As soon as link I32 rises the contact 245 will also rise, but armature 238 will remain in the Figure 11 position until coil 234 is again energized.

It will thus be observed that the cappinghead cannot be moved downwardly to capping position until the container is absolutely stationary upon the stationary supporting plate 2| and that as soon as it reaches full downward position, its

energizing coil 243 will be de-energized so that it will be promptly returned to a raised position out of the path of the succeeding container.

Figure 2 illustrates a modified form of circuit controlling device 23a which may be placed in the Figure 11 circuit instead of the device 23 In the Figure 2 form the link I48 extends through a bracket I49 into a housing I 50a of the device 23a. A spring II positioned between a collar on link I48 and the outer wall of the housing serves to urge the link I I48 to an outward position, that is, to the right in Figure 2. The inner end of link I48 bears against the free end of a lever I52 pivoted at I 53 and which lever is normally held to the right by means of a leaf spring I54 fixed to the lebearing upon a pin I55. The opposite end of lever I52 pivotally carries a pawl I56 urged to upward position by means of a spring I51 surrounding its pivot. This upward position is limited by a set screw I58 adjustably mounted in a lateral extension of lever The outer end of pawl I56 engages a ratchet wheel I59 which is also engaged by a second pawl I66 pivoted at I6I. Pawl I6!) is secured to I62 normally out of engagebears against the pivot end of lever I52 when its pawl I66 isseated in one of the pocketsof the of the ratchet wheel.

' thereby servesas alimit stop for movable contact I62. The contacts I52 and I63 are suitably insulated from their operating elements.

In the operation of the control mechanism 23a of Figure 2, as a container is moved from the infeed portion of supporting conveyor II to the position on the stationary plate 2i indicated in Figure 7, the forward and lower portion of the container will engage the roller I43 of trip 22 to move the toggle mechanism toward straightened position. As a result, the long link I will move to the right with regard to Figure 7, thereby moving the link I48 to the left in Figure 2. Such movement of link I48 will cause lever I52 to swing to the left and a corresponding movement will be imparted to the pawl I56. At the instant that the container entirelyleaves conveyor II and holding device I'I, the link I45 will have moved far enough to move link I48 a proper distance to rotate ratchet wheel I59 in a clockwise direction suflicient for one tooth of the ratchet wheel to move beneath the second pawl I 60 and lift the same, thereby swinging contact I62 against contact I63. However, pawl I60 will immediately drop behind the tooth which has raised I62 will thereby be broken.

The closing of the circuit between'the contacts I62 and I63 will energize the retarded relay 228 as described in connection with Figure 11 so as to set up the Figure 11 circuit to move the capping plate 20 downwardly to move the applied cap to sealed position after the container has reached a fully stationary position, all in the manner described in connection with Figure 11.

With the Figure 2 device 23a, when the container shown in Figure 7 moves to the right to enable the toggle mechanism to resume its normal position in the path of the next container, link I48 will return to the right causing pawl I56 to ride back and drop behind the next tooth The second pawl I60 will, of course, prevent the ratchet wheel from rotating in a counter-clockwise direction during-the dragging movement of pawl I 56 along the ratchet wheel. Spring I54 moves lever I 52 to the right as soon as the pressure on link I46 is released and the spring I51 holds pawl I56 in the upper position shown in Figure 2 thoughpermitting it to swing downwardly sufficiently to ride back over the adjacent tooth of the ratchet wheel.

It will be understood that. to adjust the machine for operation, the trip 22 will be so positioned that it will be actuated by the final movement of a container upon stationary plate 2I so that capping plate 20 will not descend-until the container is absolutely-stationary. The capping head Will also be so positioned that it will be centrally over the container. Thus, the cap will be moved to sealed position by a force applied in an entirely vertical direction.

As is illustrated in Figures3, 6 and 7, the steam duct I3 is cast in one side wall of the machine and is substantially rectangular in'horizontal section. It extends from the bottom of the side wall of the steam chamber to a point closely adjacent the under-surface of the top wall 52. The inner Wall I68 of the duct is only spaced a short distance from the inner surface of chamber wall 50 in order to clearthe'adjacent edge of the conveyor II. The edge'wall- 169 of duct I3 is closely adjacent the infeed'end of the steam'chamber I2 whilethe edge wall I10 it and its engagement with contact jacent to the infeed end of .the holding and centering mechanism I1. Hood I5 is preferably removable from duct 3 to render the screen Hi accessible.

Superheated dry steam under a relatively low pressure, for example, from one to five pounds,

is delivered to the lower portion of the duct [3 through the steam pipe 14. As shown in Figure 3, the outlet end of pipe 14 preferably has either a return bend uponthe same or is so angled that it will not direct the steam upwardly. i V

The steam received throughthe pipe it will rise through the duct l3 andpass' through vertically spaced fine mesh wire screens it which are preferably of inverted V-shape in transverse section. The screens l6 serve to entirelybreak the force of the steam and cause it to move from the wide mouth of the duct in a cloud. The V-shape of the screens it permits any condensate to move down'along their inclined portions so as not to clog them. Such condensation may eventually move out of the duct l3 through a drain HI.

In order to guide the steam rising from the duct l3 toward the .outfeed end of'chamber i2 and at the same time enable it to rise to the extreme top portion of the tunneL'the, upper end of duct I3 is provided with a hood comprising an inclined top plate I12 and vertical side plates I13. Screen IB may be horizontal or may be slightly inclined as shown in Figure 3. The primary purpose of having screen l6 inclined as shown in Figure 3 is to position it substantially parallel to the top wall I12 of the hood and thereby provide an unrestricted path between the screen and the shield.

It will be observed that the steam flowing from the wide mouth of duct I3 over its top edge H5 1 will enter the extreme upper portion of the steam chamber and because the steam is directed upwardly rather than laterally, the cloud of steam formed in the chamber will extend from the roof of the chamber downwardly. That is, there can be no layer of air between the steam cloud and the roof as frequently occurs when the steam is directed laterally at a point spaced downwardly from the roof of the steam chamber.

Since the flow of steam into the steam chamber is not under force but is at substantially atmospheric pressure, no drafts are created at any point i and a temperature of 212 is readily maintained within the upper portion of the steam chamber. The open filled containers-entering the steam cloud will quickly have the air in their head spaces replaced by the body of steam so that when-they move into engagement with the holding and centering mechanism I1. they will contain no air. Because the containers come into contact with some steam from the cloud just as they enter the tunnel they will be given a gradual heating effect, preventingcondensation. In other words, containers do not suddenly move from open atmosphere into the path of a steam jet which will con-' dense in the container head space. Since the caps are heated in the chute ii! to a temperature approaching 212, no moisture will be condensed upon the same when they move into the lower portion of the chute and into contact with the steam cloud to have their interiors filled with steam. Therefore, when the applied cap is moved to sealed position upon thecontainer by the capping head 20, the head space'of the container will be filled with dry steam.

It is to be noted that since the steam locked in the head space of a sealed container has no Tpressure andbecause the container will be surrounded by steam at 'a-temperature identical with that of the steam sealed within the head spaces,

the sealedcap has no tendency whatever to rise from sealed position when the capping head rises.

This same situation holds true when the sealed container is moved ofl stationary plate 2| by the succeeding container and into the open atmos- "space is only at atmospheric pressure, it cannot cause the cap tolift and, therefore, no means to hold the cap sealed during cooling is required. By the present apparatus and method, the container and particularly the cap will both be simultaneously and uniformly subjected to atmospheric temperature almost immediately after capping ha been performed and quick uniform cooling to contract the steam is assured.

Since the present method and apparatus insures that caps will have no tendency to rise from containers between the moment they have been moved to a sealed position and the time when the steam condenses to create a low pressure condition in the container head space, the invention may be used with caps which are held sealed primarily by a low pressure condition as well as with caps provided with some type of locking means.

" As has been indicated above, the inclusion of a vertically moving capping or sealing element in the present invention is found to be highly advantageous and a considerable improvement upon a continuously moving capping element of endless form. More particularly, while an endless capping or sealing element has the theoretical value of sealing containers at greater speed because it does not require that the movement of the containers be stopped, this theoretical advantage is altogether offset by the fact that containers may be upset or their caps either distorted or dislodged by the'endless and moving element.

' The capping element of the present invention, with its control so designed that the capping head cannot descend until the container is stationary,

entirely eliminates all of the defects of the endless type of head. Also, since by the present inventionthe capping element is immediately retracted or raised so as to be out of contact with the container which has just been scaled, it is not necessary to widely space the containers delivered to the apparatus. That is, containers can be closely spaced when delivered to the apparatus because the stopping of a container for sealing is only momentary and the following container can, therefore, quickly contact with it to place it upon the outfeed portion of the supporting conveyor.

Theluse of a quickly operable sealing element such as provided by the present invention has the further advantage of insuring that steam will be quickly entrapped within the container head space while it is still at maximum temperature. That is, with the endless type of sealing element, the cap is only gradually applied to the container and the steam within the container head space may condense or be cooled before the sealing is entirely performed. Naturally; if any portion of the steam condenses, air may enter the head space to raise the final pressure in the container head space.

Continuously moving endless sealing elements usually extend from one end of the steam tunnel. The positioning of the present sealing element entirely within the highly heated steam chamber causes the sealing element to be maintained at a high temperature so that it cannot condense steam trapped in the container head space. In machines of the endless belt type, the belt becomes cooled, either because cooling liquid is directed upon it or because it moves into a cooler atmosphere as indicated above. Naturally, if a cap not yet fully sealed upon the container at the time that this cooling begins, condensation of steam will occur, with a resulting higher head space pressure.

The use of a reciprocating capping element is particularly efficient in sealin caps of the type having locking lugs upon their skirts. That is, by the present invention the caps are moved directly downwardly by a straight line movement to a sealed position upon the container. Sealing apparatus of the endless belt type are particularly inefficient in applying this type of cap because such caps are more apt to become tilted upon initial contact with the sealing element due to fact that the lugs prevent them from being readily moved to a sealed position upon the container. For example, if a lug type cap moves adjacent the sealing element with one of its lugs resting upon the mouth of the container, it may not besubsequently properly seated by an endless sealing element, but, instead, may be bent or otherwise distorted or entirely knocked ofi the container. The arrangement of the present inve tion is therefore equally useful and efficient in applying caps of both the lug type as well as those which rely primarily upon the lowered pressure within the head space to retain them in sealed position.

As has been stated above, it has heretofore been thought that if containers were stopped for sealing, they might fall over, or at least that any liquid contents would be so disturbed as to cause spilling. Therefore, continuously moving sealing elements were believed necessary, even though such elements themselves may cause upsetting and improper application of caps and are not satisfactory for sealing lug type caps. I have discovered that the stopping of containers filled to the usual extent by movement on to a stationary plate, as opposed to the stoppin of a container by the positive stopping of a driven chain or other container engaging element, with its resultant vibration, does not cause upsetting of containers or any spilling of their contents.

Hence, the use of the much more practical vertically moving sealing element is made entirely feasible.

The general operation of the present apparatus and method have been described in the opening portion of thi specification and the specific operation of the various elements have been described in connection with the detailed description of the construction of such elements.

16 Subject matter disclosed but not claimed'herein may be claimed in my application for Container sealing apparatus, Serial No, 685,443, filed July 22, 1946, as a continuation-in-part of the present case.

The terminology used in the specification is for the purpose of description and not of limitation, the scope of the invention'being indicated in the claims.

I claim:

1. In a container capping apparatus, a base, a straight-line steam tunnel mounted on said base, said tunnel including a top wall and two side walls to define an inlet and an outlet at the respective opposite ends of said walls, conveyor means carried by said base to move containers through the tunnel, the top wall of the tunnel being positioned to lie closely adjacent the mouths of the containers, means carried by and below the tunnel top wall to apply and seal caps upon containers, a steam duct fixed with respect to a side Wall of said tunnel in advance of the cap applying means, means to deliver steam to said duct at a relatively low pressure above atmospheric pressure, pressure reducing means in said duct to reduce the pressure of steam flowing therefrom to substantially atmospheric pressure, said duct including an outlet mouth positioned at one side of said conveyor and below but closely adjacent the plane of'th'e cap applying and sealing means,v said outlet mouth facing upwardly and in the direction in which said conveyor means moves containers through said tunnel, said steam supply means, pressure reducing means and the facing direction of the duct mouth having the combined function of maintaining a quiet body of steam in the area occupied by said applying and sealing means and with the body of steam extending from the top wall of the tunnel to a point below and closely adjacent the plane of the container mouths, said tunnel being vertically adjustable with respect to said base and conveyor and means cooperating with a wall of saidtunnel to move said tunnel and duct vertically with respect to said base and thereby enable containers of various sizes to be capped.

2. An apparatus of the character, defined in claim 1 wherein the top wall of the tunnel and the cap applying and sealing means carried thereby are horizontally adjustable with respect to the side walls of the tunnel and said duct, and means is provided to move the top wall and applying and sealing means horizontally to thereby adjust the point with respect to said steam supply duct at which a cap is applied and sealed upon a container.

HARRY A. RAU.

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