US2975740A - Can end seamer - Google Patents

Description

March 21, 1961 c. J. SMITH ETAL 2,975,740

CAN END SEAMER Filed Oct. 10, 1956 5 Sheets-Sheet 1 f/GL/ IN VEN TORS CLARENCE J SMITH BY RALPH M. PETERSON A TTORNEY March 21, 1961 c. J. SMITH ETAL 2,975,740

CAN END SEAMER Filed Oct. 10, 1956 5 Sheets-Sheet 2 INVENTORS CLARENCE J SMITH 8O RALPH M PETERSON 26/ BY 77 78 75 75 ATTORNEY March 21, 1961 c. J. SMITH ETAL CAN END SEAMER Filed. Oct. 10. 1956 5 Sheets-Sheet 3 llz INVENTORS CLARENCE J SM/TH BY RALPH M PETERSON 60441 Z77 ATTORNEY March 21, 1961 c. J. SMITH ETAL CAN END SEAMER 5 Sheets-Sheet 4 Filed Oct. 10, 1956 March 21, 1961 c. J. SMITH ETAL 2,975,740

CAN END SEAMER Filed Oct. 10, 1956 s Sheets-Sheet 5 20m [90k IOO IOZCx.

INVENTORS CLARENCE J SM/ TH BY MLPH M PE TERSON A 7' TORNEV during the second seaming operation.

CAN END SEAMER V V Clarence J. Smith and Ralph M. Peterson, Rockford, Ill.,

assignors to -W. F. & John Barnes Company, Rockford,

111., a corporation of Illinois Filed on. '10, 1956, St. No. 615,145

1 Claim. (Cl. 113-17) This invention relates to a can end seamer and method of end seaming. More particularly, it relates to a can end seamer of the type known as a double seamer which applies can ends or covers to can bodies and forms a double seam joint between the ends and the bodies.

Can end seaming operations must, in most cases, be carried out at high speed. Where food or the like intendedfor human or animal consumption is canned, the end seams must be airtight. Therefore, the machines employed to close cans must be capable of operating at high speed, yet with great dependability.

These considerations and problems apply with special.

force to double seamers because the, seaming operation is more complex, being carriedout in two steps or operations known in the art as the first operation and the .second operation, In the first operation the curl r 1; '1 {Cd States Pdffifit of the can end and the flange of the can body are I arel roll type seamers wherein an assembled can body and. can end are clamped between a lifter padand a seaming chuck; are rotated from an entry point to an exit point or a discharge point; and, during transit from the entry point to the discharge, are caused to spin.

Meanwhile, during the first seaming operation a first operation seaming roll isimoved by suitable means such as a cam into engagement withthe can end curl and can body flange. "It is the pressure of the seaming roll and the spinning of the can end and can body which I bring about the seam formation to form a first operation seam. This procedure (i.e., contact with a seaming roll. and spinning of the can end and 'can body) is repeated It is prevailing practice, and it is deemed to be a necessary practice to spin each assembled can end and can body many times during each seaming operation.

Thus it is common practice "to spin an assembled can end and canbody about'l 8 to 30 revolutions during each and can bodies many times during each spinning jopena- 7 tion in order to obtain a good seam. l V

We have found to the contrary, namely, that good seams can be formed by spinning each can endfand can body not greatly inexcess oil revolution during i feac li seaming op'enation, and We have further discovered that there are certain'm'arked disadVantagesin: previous -practice inthis regard which areeliminated or greatly, H lessened "by-our practice of spinning each can end and; f can-body not greatly in excess of. one revolution during each seaming'operation. j a i Thus; we have found that the multiple spinning of i prior practicefcauses work hardening of the metal of j ftheend seam, thereby-causing deterioration of the metal.

. This deterioration. is especially pronounced in the case of tin linedcans, -;AS a result of such. deterioration the' end ibecome discolored, even black-"on standing.

" .-d-isc'oloration meets with consumerresistance .and

1 5 ice i f applying a lacguerto'bothi' ice We avoid or greatly reduce such work hardening, metal deterioration and discoloration, and we eliminate the necessity of lacquering can ends as a means of preventing blackening of end seams by greatly reducing the number of. revolutions through which each can end and can body spin during each seaming operation. We find that a good seam results notwithstanding contrary views of others skilled in the art.

We may accomplish our object in this regard by means of conventional roll type seamers by using them to spin each can end and can body. through, for example, one revolution per seaming operation plus a reasonable overlap, e.g .,.a 50% overlap. Thus, the span between the inlet and discharge points may be shortened or the design of therotating parts may be such as to spin each can endand can body 1 /2 revolutions during each seaming operation. For example in one type of roll type double seamer, first and second operation seaming rolls are employed for each seaming head'and, during each cycle of operation, a first operation cam acts on the first operation roll or rolls of each seaming headto contact the same with the can body flange and can end and curl 'held by that particular head; then a second operation cam acts on the second operation roll or rolls to contact the same with such flange and curl. In accordance with th e present invention the dwells of these cams would'be modified. to cause seaming contact during each seaming operation for a period of about 1 /2 can reovlutions for the largest size of can, rather than about 18 revolutions as presently practiced. I V V V However, we prefer to employ the principles of a bar type seamer such as shown in Kruse U.S. Patent No.'

nection with the present invention is that described and claimed inQLaxoILS; Patent NO.[2,727,481, granted December 2, 1955, entitled :Can End Seamer, hereinafter referred to: as the Laxo patent.

a The end seamer of the Laxo patenternbodies' certain novel andvery, advantageous features, among which may be mentioned the following: Instead of employing'searn ing rolls which are .moved by cams into and out of engagement with can bodies and can ends, the seamer of the Laxo'patent employs a stationary seaming-bar,

usually of circular shape, A resilient force is applied tothe seaming chucks which, clamp the canendsto' the can bodies, to holdpthe assembled can endsand can bodies'tin operative engagement with the stationary seaming' bar. Me'anwhile.;the seaming chucks-and the assembled can bodies and can ends spin about their individnal 3X6 S 3.I1d travel alongthe seaming bar.

*Inthe seamer of the Laxo patent, if double seaming is to beeifectemthe seaming'baris constructed in two f sections for t hejfir st and second is'eaming operations, respectively I The machine of the=Laxo patent is especially well adapted. for purposes of the present invention. y ln past practice'withthisrnachine it has been; customary and has been; deemed preferable to employ a first operation 5 seamingb ar' having a length equal to about 2 /2 times thecircumference of the largest ,CfllljbOdY to be seamed.

Thus, in a machine intendedfor cans ranging from No.- I

2Q2fto No. 4Q4 in size,"a first operation'seaming bar 7 would be employed which; is about 33 /2" long (i.e.-,.

3.14 x4125-x 2.5 A seamingbar of this length would spin or revolve each'No. 404' can body and can end about 2 /2,: timesand it- 'would'spin each No. 202 can- In this type of Morebody and can end about times. A second operation seaming bar of the same length would also be employed which would, therefore, revolve each No. 404 can end and can body 2 /2 times and each No. 202 can end and can body 5 times. Each of the seaming bars of the Laxo patent, as previously designed, would have a long entry taper. Thus, assuming a circular bar with the seaming groove on the concave side of the bar, the bar would be sprung or biased along a considerable portion of its length so as todepart from a true circular shape. By way of specific example, a 34" bar intended as the first operation bar for a seamer for No. 202 to 404 cans would be mounted in a frame ring, then biased outwardly from the seaming chucks and the central axis of the machine, for a length of about 13 /2" commencing at its leading or entry end. Therefore, an assembled No. 404 can end and can body entering the bar would be subjected to gradually increasing seaming pressure for one complete revolution. At the end of this taper the arc of the bar would be circular and the seaming pressure would'remain virtually constant. Similar considerations would apply to the second operation bar.

It may be said that prior practice with the machine of the Laxo patent has been a great improvement over past and present practice with roll type seamers because, among other things, can bodies and can ends are rotated through much fewer revolutions per seaming operation; i.e., about 2 /2 to 5 as compared to 18 to 30. Nevertheless, it has previously been deemed important in the machine of the Laxo patent to apply a gradually increasing seaming pressure throughout at least on revolution during each seaming operation.

We have found, on the contrary, that the seaming bar of the Laxo patent may be greatly shortened to a length not greatly in excess of the circumference of the largest can size intended to be seamed. For example, in a machine intended for cans ranging from No. 202 to No. 404 in size, each bar would have a total length of about 13 /2" plus a reasonable overlap, or a total of about This contrasts with previous practice in which the bar would be about 34" long. In this connection we provide a tapered entry end for the first operation bar which is very short in length, e.g., about one inch for a bar intended for No. 202' to No. 404 cans. This short taper acts to supply a very rapidly increasing seaming pressure to each can end and can body as it commences the first seaming operation. The remainder of the first operation seaming bar has no taper and, if it is a circular bar, it hasa constant radius.

The second operation seaming bar need not have any entry taper.. It is, however, preferred that the entry end of the second operation bar be chamfered to permit extraction 'ofa can at the end of the first seaming operation for-inspection of the first operation seam.

The improvements thus described with reference to the machine of the Laxo patent have several advantages. Thus less work hardening and metal deterioration is caused (although the machine of the Laxo patent is itselfa great improvement in this respect over conventional rolltype scamers) and smaller-seaming bars may be employed. Small bars permit smaller machines and involve less machining o'fparts and less wear of seaming chucks, etc. r 7

Another feature of the machine of the Laxopatent which has given some reason forimprovementhas been the specific means employed to urge the seaming spindles and chucks toward the seaming bars. Springs have been employed for this purpose which urge the seaming spinthe Laxo machine, but at high speeds inertia becomes a limiting factor in the ability of the springs to perform their intended function.

Among the objects of the present invention are, therefore, the following:

To provide improved can end seaming machines, partieularly for double seam formation.

To provide can end scamers which seam can ends to bodies without excessive rolling or spinning of the cans during seaming.

To avoid work hardening, metal deterioration, and/or discoloration of end seams of cans.

To shorten the seaming bar of, and generally to improve upon, the bar type of end seamer.

To provide improved mounting for seaming chucks in bar type scamers.

These and other objects of the invention will be apparent from the ensuing description and the appended claims. Y

One form of the invention is illustrated by way of example in the accompanying drawings, in which:

Figure 1 is a view partly in side elevation and partly in section of the machine of the present invention.

Figure 2 is a vertical midsection taken through one of the seaming chuck assemblies illustrating the manner in which resiliency is imparted to the seaming chuck in a manner to minimize inertia and other disadvantages of yielding chucks.

Figure 3 is a view similar to that of Figure 2 but showing the chuck assembly at a different stage of operation.

Figure 4 is a top plan view of the first and second operation seaming bars employed in the machine of the present invention for a double seaming operation, such figure illustrating the manner in which the bars are designed to reduce the number of revolutions required for each assembled can body and can cover and to reduce the lengths of the seaming bars.

Figure 5 is a section taken along the line 55 of Figure 4, such view also showing the seaming bars mounted on the frame of the machine.

Figure 6 is a section taken along the line 6-6 of Figure 2, showing the detent ring of the chuck assembly in top plan.

Figure 7 is a fragmentary top plan view of the first operation seaming bar showing the entry end thereof.

Figure 8 is a section taken along the line 8-8 of Figure 7, such view. also showing the seaming bar dle and chuck radially outwardly toward the seaming bars. These springs maintain the chucks in operative relation to the scanning bars at all times during the seamingoperation or operations, yet they retract or flex when required b'yextra metal thickness, e.g.,- at the juncture of an end seam'and a side seam. This problem is, in general, ,jvery efiectivelysolved by the construction of mounted on the frame of the machine.

Referring now to the drawings and more particularly toFigure l, the machine of the invention is generally designated by the reference numeral 10. It. comprises a main stationary frame 11 within which is jcurnaled a central, hollow shaft 12 which supports a lower assembly 13 and an upper assembly 14. The lower assembly 13 comprises a skirt or spider 15 which is integral with the shaft 12 and which carries a plurality of lifter pads 16 each of which is rotatably mounted in the spider 15 so as to be free to spin about its own axis as it rotates about the-axis of the shaft 12. Each lifter pad 16 is supported by a shaft 16a which is nonrotatable relatively to the spider 15 but is slideablc in a vertical direction relatively to the spider. Journale d in the lower end of each of the shafts 16a .is a cam follower roller 17 which rolls on a lifter cam 18. As is well known in the can making art, it is the function of the cam 18 to act on the cam rollers 17 andthe shafts 16a to raise and lower the lifter pads =16. Thus when a can body (one of which is shown at 19 in Figure l) with a can cover superimposed thereon is delivered to and seated upon a lifter pad'16, the latter 1 formed inthe sleeve 25.

The upper assembly 14 comprises a skirt or spider 21 which is adjustable vertically by a-nut 22 threaded to a screw 23. By rotating the screw 23 the height of the upper assembly 14 is adjusted for a particular can height. The spider 21 is formed along its outer edge or periphery with sleeves 25 each of which receives a chuck assembly generally designated by the reference numeral 26.

Referring now more particularly to Figure 2, one of the seaming chuck assemblies 2 6 is thereshown. It comprises a spindle 27 which is formed with an axial passage 28 to receive a knockout rod 29 to the lower end of which is threaded a knockout head 30 formed with slots 31 to receive a Wrench. At its upper enda steel ball 32 is provided which is seated in a socket 33 formed in a nut 34 threaded to theupper end of. the knockout rod 29'. An expansion spring 35 is provided which is compressed within the axial passage 28 between a shoulder 40* on the knockout rod 29 and a shoulder 41 on the seaming spindle 27. It will be apparent that the spring 35 will normally maintain the knockout rod 29 in its up position illustrated in Figure 2 A knockout cam (not shown) is provided for acting on the steel ball 32 toforce the knockout rod 29 tothe down position which is illustrated in Figure 3,.thereby detaching a can body and can end from the seaming chuck at the conclusion of the seaming operation. a V

The seaming spindle 27 is journaled in upper bearings 42 and lower bearings 43. .The lower bearings 43 are held inplace by a nut 44 threaded to the spindle "and a lock washer 44a. The upper bearing 42 rests upon a ring 47 fixed to the spindle 27 and beneath the ring 47 there is provideda guard member or shield 48.which is supported "by a spacer 48a and which receives a mating guard member or shield 49. The purpose of the shielding 48 and 49 is to prevent lubricant, condensed steam and other matter of an objectionable character from leaking downwardly along the Spindle to the chuck,

, thence intothe cans asthey are being closed. A drive sprocket 50 is provided which is driven by achain 51 which is fixed to the frame of themachine. The sprocket 90. In so doing the balls 95 will compress the springs 94.

is "rotatably mountedon the spindle 27 by meansoi suitable bearings .(not shown) so that thespindle is free 7 to rotate relatively to the sprocket, except that a driving connection is provided between the sprocket 50 and the spindlefl27in the'form of an overrunning clutch (not shown) The'overrunning clutch connection may bethat described and claimed in Laxo=and Werge Patent Application Serial No. 410,374, filed Febi-uary' 15,1954, en-

titled Double Seamer, Dr'it may be any other suitable type of. overrunning clutch. The purpose of such overrunning clutch is'to allow'the spindle to rotate'treely by reason of frictional. engagement of the seaming chuck with detent sockets 90. The holder element 79-is tapped at 91 to receive the screws 78. As will be seen from an inspection of Figure 6, there are three pairs of detent sockets" 90 which are arranged symmetrically. The spring holder 79 is formed with an equal number of passages 93 which are in registry with the detent sockets 90. A spring 94 is disposed within each passage 93 and is compressed between the spindle head 46 and a steel ball 95 which is seated in the respective socket 90.

It will be observed that the detent ring 82 is fitted snugly to the spindle head 46 and to the nut 83. Therefore, the detent ring has no substantial play either in a vertical plane or in a horizontal plane. However, there is substantial play in a horizontal plane between the spring holder 79 on the one hand and the detent ring 82 and spindle head 46 on the other hand. There is also a sub-. stantial play between the bushings 80 and the detent ring 82. It will,therefore, be apparent that a small but substantial lateral shifting of the chuck 75 is made possible. However, the chuck 75 is normally held in exactly centered position, i.e., exactly coaxial to the spindle27, by the detent sockets 90, steel balls 95 and springs 94. It will be apparent that if a lateral force of sutficient magnitude is applied to the chuck75, for example, from left to right as viewed in Figure 2, the chuck will shift laterally and the steel balls 95 will pop out of their sockets However, instantly when the disturbing force is relieved the springs 94 will act to restore the steel balls 92 to their detent sockets 9t and to restore the chuck 75 to its normal, coaxial position.

It is an important advantage of this construction and mode of operation that a shiftable chuck is employed, i.e., shiftable in a lateral plane toward and from a seaming bar; that the chuck is normally held in a precisely centered position by resilient means which yields to allow shifting of the chuck in response to metal thick? ness interposed between the chuck and the seaming bar; and that the seaming spindle itself is not shifted. This construction overcomes the disadvantages noted above.

' first seaming operation and the second seamingoperation,

with a can body, canend and seaming'bargbut to drive the spindle whenever the seaming chuck tends :to slip or ,o

A sealing-member is provided at havingfbutwardly projecting annular ribs 161 which mesh' withgrooves 62 Theuseaming chuck proper; is indicated by'thereferuoij flangein operative engagementwith a seaming bar. The a .chucki"i'is =bolted. by. shouldertscrewsqs to asp ing holder'elem'ent979. having' a functions? described hereint after. 1 Itwill be seenthatthechuck 75 is a change part which can bej'ieasily and speedily changed (for cans of dif "-ferent'jsizegand{for replacement of worn chucks. a The screws 7 8 extend through bushings which are 'jlocated in passages 81 formed irr a detent ring. 82. The

detent-ring 82 ieclamped to thespindle;27[bya nut. 83,

respectively. These bars are of substantially identical.

'design except as noted hereinafter,

Referring more particularly to Figures 5 and 8, it will be seen that the first operation seaming bar is formed with a seaming groove 1052 which receives an assembled. 7 can body. flange 19a and can cover "curl 20a for the. "purpose of forming anend seam. The seaming bar is also formed with a groove ltllahaving a pose explainedhereinafter.

A clamp memberlla. is shown bolted to a mounting ring '104,'such mounting ring "being formed with avtrans; I

the groove 1433, in the'fseaming'bar. A pair ofnuts'109 are provided which "are ithreaded'to. the outer threaded 1 endiotthe belt 106. ,Th'e'mounting ring 104 is rformed V V Y with another transyerselpassag'elld which receives a set $016Wj115 which is proyidedwith alockf nu't1 116.v

It will 'be seen thatthere are several "such adjustment assemblies, each, sueh' adjusting assembly being generally designated by the r'eferepcefnumeral 1171f 'Ihese 'adj ust- Thus'inertia does not have i mounting pure heretofore;

as viewed in Figure 5, the nuts 109 on the bolt "106 are loosened and the set screw 115 is screwed inwardly. As Will be seen, the set screw 115 bears against the rear of the seaming bar. Accordingly such manipulations will push the seaming bar inwardly, or to the left as viewed in Figure 5. When suitable adjustment has been made, the nuts 109 are also tightened, thereby clamping the seaming bar in adjusted position.

If it is desired to move the seaming bar outwardly, or to the right as viewed in Figure 5, the nut 116 will be loosened, likewise the outer nut 109 and set screw 115 rotated outwardly. Then the inner nut 109 will be rotated so as to draw the bolt 106 outwardly or to the right thereby moving the seaming bar outwardly to the predetermined position of set screw 115. When suitable adjustment has been made the nuts 109 and 116 are tightened, thereby clamping the bar in adjusted position.

In accordance with preferred practice in the past, in connection with the machine of the Laxo patent, the seaming bars 100 and 101 would be sprung, as by means of the bolts 106 to give the entry portion of each bar an eccentricity in an outward direction, to the end that a gradually increasing seaming pressure is applied to each assembled can end and can body. However, in accordance with the present invention no such practice is followed. Thus in the case of a circular bar such as shown at 100 and 101, the bar will have a true circular are along its entire length and it will not be sprung or biased. Moreover, the length of each bar will be sufiicient only to revolve the largest size of can end and can body (i.e., the largest size for which the machine is designed) not greatly in excess of one revolution, e.g., l /z revolutions. That is, each of the bars 100 and 101 intended for cans of, say, No. 404 size maximum will have a length of about 1%. x 4% x 3.14:20 inches. By way of contrast,

previous thinking and practice would employ bars each of which would have a length of 2 /2 x 4% x 3.14=about 34 inches.

It will be understood that bars of noncircular shape, e.g., wavy, sinuous bars for rectangular or oval cans, and straight line bars may also be-employed; e.g., the sinuous bars shown in Figure l of the Laxo patent. In all such cases the principles of our invention are applicable, i.e., a bar length of about 1% times the can circumference may be employed. It may, however, be preferred to increase the length of the sinuous bar because of diffioulty in seaming at corners.

The seaming bars 100 and 101 are maintained as true arcs of circles or, in other words, each is maintained throughout substantially its entire length at the same distance from the chuck axis. Therefore a constant seaming pressure is applied throughout substantially the entire seamingoperation. Nevertheless, it is preferred to start the first seaming operation at a lesser pressure and to increase this pressurerapidly. This object is preferably accomplished by the means now to be described.

Referring now more particularly to Figures 7 and 8, v

the entry end A of the first operation seaming bar 100 is modified in accordance with the present invention to eliminate a lengthy entry taper, to avoid a gradual increase of seaming pressure and to increase the seaming Y pressure very rapidly. A very short entry section of the bar 100 is indicated generally by the reference numeral 125. It will be seen that the overhang 126 of'the bar .100 has the same radius along the entry section 125 as elsewhere along the bar, but that the groove segment 102a is recessed much further than the main groove 102;

As indicated in Figure 4, the second operation seaming bar 101 need not have an entry section similar to the entry section 125. It is chamfered at 125a to assist in initial contact of the partially formed end searn with the bar 101. To allow extraction of a can to inspect the first operation seam a suitable space is left between the first operation bar 100 and the second operation bar 101, as illustrated. Thus it is common practice to run a machine slowly, to stop it when a chuck reaches the end of the first operation bar and to extricate the respective can for inspection of the first operation seam. The purpose of the spacing between the bars is to allow a can to be removed for inspection purposes.

It will, therefore, be apparent that a can closing machine has been provided which embodies certain very advantageous features, and that a novel and advantageous method and technique have been developed for can closing operation, particularly for double seam formation.

We claim:

A' can end seaming machine for forming double end seams on cans, said machine comprising a frame, a plurality of seaming chuck assemblies rotatable insaid frame about a central axis, each seaming chuck assembly being also capable of spinning about its individual axis and clamping together an assembled can body and can cover in coaxial relation to the seaming chuck assembly with the cover overlying one end of the can body and overlapping the same at the commencement of the first seaming operation; means for rotating said seaming chuck assemblies in unison about said central axis; a mechanism including means mounted on said frame for spinning said seaming chuck assemblies simultaneously about their individual axes during rotation of said assemblies; said machine also comprising two circular stationary seaming bars fixed to the frame, said bars being in the same plane and being concentric to said central axis along substantially their entire lengths, said, seaming chuck assemblies and seaming bars being cooperable to form end seams from assembled can bodies and can covers, the first of said bars being operable in conjunction with the seaming chuck assemblies to initiate and to perform the first operation of double seam formation, the second of said bars being operable in conjunction with the seaming chuck assemblies to complete the end seam formation by performing the second operation of double end seam formation; said machine being designed to operate 7 on can bodies and can covers up to a maximum can and the. groove segment liiza'comm'ences with a rounded end portion 127 and then slopes along a straight diagonal line 128 to a junction point 129 withthe main portion of the groove 102. The entry section of the bar may have a length of only about one inch{for"a L20 inch-bar:

intended fdr-NoQlO i cans maximu'rnc This contrasts withan'entry"section ofiabout 13 .51in,"machines, built body diameter of D inches; said machine being further characterized by the fact that each of said seaming bars is concentric to said central axis, has substantially no departure from such concentricity throughout substantially its entire length and has a length not greatly exceeding about 1.5 x 3.14 x D; said first seaming bar being further characterized by a relatively short, relatively steep tapered section at its entiy end, said tapered section being the first section of'saidbar to be contacted by an assembled can body and can cover and acting to apply a rapidly increasing pressure to an References Cited in the file of this patent UNITED STATES PATENTS Kruse -1 June 22, 1915 1,278,941 Kruse Sept. 17, 1918 1,313,998 Kruse Aug. 26, 1919 1,400,391 Troyer Dec. 13, 1921 7 2,100,480 Hirshmau NOV. 30, 1937 2,321,527 Shera Q. June 8, 1943 2,369,763 Stover et a1 Feb. 20, 1945 2,455,737 Coyle Dec. 7, 19.43 2,460,296 Kinney Feb. 1,1949 2,727,481 Laxo Dec. 20, 1955

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