US2859507A - Stereotype finishing machine - Google Patents

Description

Nov. 11, 1958 c. v. KNELL STEREQTYPE FINISHING MACHINE 8 Sheets-Sheet 1 Original Filed Nov. 16, 1945 INVENTOR. C. VERNE KNELL ATTYS.

Nov. 11,1958 0. v. KNELL 2,85

STEREOTYPE FINISHING MACHINE 7 Original Filed Nov. 16, 1945 8 Sheets-Sheet 2 INVENTOR. C. VERNE KNELL Arrvs 8 Sheets-Sheet 3 Nov. 11, 1958 c. v. KN'ELL STEREOTYPE FINISHING MACHINE Original Filed Nov. 16, 1945 Original Filed Nov. 16, 1945 STEREOTYPE FINISHING MACHINE 8 Sheets-Sheet 4 8 o r l g Q I INVENTOR;

(I. VERNE kNELL.

, gully"! W L A V ATTYS.

Nov. 11, 1958 c. V. KNELL STEREOTYPE FINISHING MACHINE 8 Sheets-Sheet 5 R T. T N E V IN.

1 Original Filed Nov. 16, 1945 C. Venus kwcu. BY [MI/two, W N

Arrvs,

Nov. 11, 1958 c. v. KNELL 2,859,507

STEREOTYPE FINISHING MACHINE Original Filed Nov. 16, 1945 '8 Sheets-Sheet 6 INVENTOR. C. VERNE KNELL ATTYS Nov. 11, 1958 c. v. KNELL YSTEREOTYPE FINISHING MACHINE 8 Sheets-Sheet 7 Original Filed Nov. 16, 1945 INVENTOR C Venus KNELL A rrvs.

Nov. 11, 1958 c. v. KNELL 2,859,507

STEREOTYPE FINISHING MACHINE .Original Filed Nov. 16, 1945 8 Sheets-Sheet 8 INVENTOR. C. VERNE KNELL Arr Y5.

United States STEREOTYPE FHJHSHENG -MACHINE .Christopher Verne Knell, Northxfianton, hio,'assignor,

--by mesne assignments, to MiehleGoss-Dexter, Incorporated, Wilmington, Del., a corporation of Delaware Original application November 16, 1945, Serial No.

629,122, now Patent No. 2,664,238, dated-January '5,

1954. Divided and this appiication December 30, 1953, Serial No. 401,210

4 Claims. (Cl. 29-21) This invention relates to a novel and improved machine for finishing or machining cylindrically curved printing. plates, particularly stereotype plates adapted to be locked up undertension on the plate cylinders of a printing press.

This application is a division of my copending application Serial No. 629,122, filed November 16, 1945, now

-U. S. Patent. No. 2,664,788, issuedlanuary 5, 1954.

An object of the invention is to finish the interior surxface'of a printing plate into true cylindrical form and to form axially spaced tension lockup pockets in the under- "side of the plate adjacent its straight edges, while the plateis'mounted on a plate holder, the pockets being adapted to be engaged by plate tensioning hooks of the type employed on the plate cylinders of printing presses. A further object of the invention is to bore the interior surface of a plate and to form tension lockup pockets while the plate is mounted on a single work holder. Another object of the invention is to press a plate firmly against a work holder while finishing the cylindrically curved inner surface of the plate and forming tension I emplary plate-finishing machine, with certain parts broken away.

Fig. 3is an enlarged end elevational view showing boring and pocket milling mechanisms embodied in the machine of'Fig. 1, certain parts being broken away and others being. shown in section.

Fig. 4 is an elevational sectional view taken generally along the line 4-4 in Fig. 3.

"Fig. 5 is a fragmentary enlarged end elevational view .of the machine, particularly the boring mechanism, with certain parts broken away and others shown in sections.

Fig. 6 is an elevational sectional view taken generally along a broken line'66 in Fig. 5.

Fig. 7 is a fragmentary plan view of the pocket milling "mechanism, with certain parts shown in sectionhalong line 7-7 in Fig. 3.

Fig.8 is a fragmentary enlarged elevational sectional view .taken generallyalong line 88 inFig. 4, and showing a-.milling head embodiedv in the illustrative embodi- 'ment of Fig. 1. The. sectionv line for Fig. Sis also shown in'Fig. .10.

"Fig. 9 is afragmentary plan view of the milling head shown inFig- 8.

Fig. 10 is .a fi'agmentary horizontal sectional view taken generally along line 10-40 in Fig. "8.

atent Fig. '11 is "a side elevational sectional "view, taken 2,859,507 Patented Nov. :1 1, .1958

.generally alonga-line 11-11 in Fig. 12, and showing a printing-plate after being finished on the illustrative plate-finishing machine.

Fig. 12.is a transverse sectional view of the printing ,plate taken generally along a line 12-12 in Fig. 11.

While the invention is susceptible of various modifications and alternative constructions, there is shown in the drawings and will herein be described in detail the 7 preferred embodiment, but it is tobe understood that there is on intention to limit the invention to the form disclosed, but it is intended to cover allmodifications,

equivalents, and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

drawingsis adapted to finish plates of the general type The cxemplary'plate-finishing machine shown in the shown-in Figs. 11 and 12. Certain featuresof such plates aredisclosed and claimed inthe Curtis S. Crafts Patent No. 2,474,889,'issued July 5, 1949, to the assignee 20' of-the present application. Reference may be had to this patent and-also to the above-mentioned copending application for. a complete description of this plate. For v.the, present, however, it will suffice" to note that Figs. 11

and 12 disclose fa semi-cylindricalplate 23 having an external cylindrically curved printing surface 61. The illustrative plate-finishing machine is adapted to finish an .accurately cylindrical interior surface 62' on the plate-23.

This interior surface 62' is adapted to be seated on and to conform closely to the outer surface of a plate cylinder of-a printing press. The plate thus provides a printing member of a predetermined size and having an accurately cylindricalprinting surface, so that the printed impressions from the plate will be of ahigh quality.

Toreduce the weight oft-the plate 23 the interior sur- .face .62 may be formed withv a series of circumferentially r'extending recesses or grooves-63 alternating with ribs 64 (Fig.15). .At intervals, the circumferential ribsv64 are intersected by longitudinally extending ribs 64A.

.These recesses 63 and ribs 64 and 64A have been omitted from'Figs. .11 and 12.for the sakeof clarity. Formed on the plate 23 are straight,.longitudinal edges 65 which are. somewhat thinner than the .main body of the plate.

.The recesses 63 are formed over the entire inner surface '62 except for unbroken areas adjacent the edges of the plate, the largest of ;these unbroken .areas being adjacent the straight edges.

-In additionto'finishing theinterior plate surface 62 .so that all'iof the ribs 64 and 64A will .lie in a uniform cylindrical surface, the illustrated plate-finishing machine is adapted to formtwo parallel series of axially spaced tension lockuppockets closely-adjacent the straight edges-65. These pockets or groovesx66 are. adapted: to

be engaged by plate-tensioning. hooks mounted on the .plate cylinders of; printing presses; each pocket having'a flat undercut-a side-67 and an oppositely facing smoothly .curve'd'oraarchedside 68 terminating in'rounded endsv69.

.To hold thejplate :23 while the cylinder inner surface -62 and the. pockets =66.are being finished, the plate-finish- .ing machine-isequipped with'arplate supporting member in'the formofaconcave; cylindrically curvedarch 20 (Fig.2)..of .a diameter and length.correspondingitothe desiredgprinting surface of thestereotype plate, and of such strength that it will not -yield appreciably :as the ,plate'isfirmly pressed into the arch -.and1-finishedzon its inner side. 'Thearch 20is heavily ribbed, securely bolted or otherwise secured to a main frame-22. Preferably the arch 20 is located substantially-midway between the longitudinal. endsof the main frame. so as to provide a plateoreceiving station A (Fig. 1) at one end of the frame, a finishing station B. under the arch .20 and aplate-delivering stationC' at the opposite end of the frame. In actual practice, the arch 20 generally has a diameter offrom 16 to 20 inches and an'tixial length of from to 5 inches, the interior surface of the arch corresponding accurately to the printing surface which is desired on the printing plates.

To receive theplate23 atthe receiving stationelrfthe plate-finishing machine is equipped with'apaiPof-spaced ledges 24 (Fig. 1) adapted to receive and support the'two straight, diametrically opposed-edges 65 of the plate.

At the finishingstation B, the plate-finishing machine is provided with a plate-supporting mechanism- 24A (Fig. 2)

adapted to clamp-the plate-against-the arch'zil. 'Platesupporting mechanisms of this general type-are well known to those skilled in' the art. Moreoven the'illustrated mechanism is disclosed and claimedin my 'copending application Serial No. 629,122, to- -whicl1=-refernce may be had for a complete disclosure' However, for the purposes of the present invention, it will sufiice to note that the plate-clamping mechanism 24A includes a pair are alinedwith the plate-receiving ledges -2 4'-so thatthe plate may he slid from thelatter to the forrner. 'The plate supports 25 and 26 are movable both vertieally-and horizontally under the control of earns 39; Four such cams 39 are provided, two for each. of the-supports 25 and 26. The earns 39 are mounted on a -pair oflongitudinal shafts 'which are connected-to a common cross shaft 53 by means of bevel gears 51 and-52. An-operating lever 54 ismounted on the cross shaft 53 to provide for simultaneous operation of all of the cams 39.

The plate-clamping mechanism 24A is arranged so that rotation of the earns 39 will raise the plate-supports 25 and 26 and at the same time will move the plate supports toward each other so as to compress or pinch the plate diametrically as it is raised into engagement with the arch 20. This diametrical compression of the plate eliminates any wiping action between the plate; and the of longitudinal supportsor rail's 25 and 26 which normally 30 arch, and thereby prevents damage to the printing sur- 1 face of the plate. The arrangement of the clamping mechanism 24A is such that the plate support 25 is raised slightly ahead of the support 26, so that the support 25 will reach the upper limit of its travel before the support 26. When the support 25 reaches its upper limit, it is retracted outwardly so that the right-hand longitudinal edge of the plate will move into engagement with the arch by the time that the left-hand support 26'has reached its upper limit. The left-hand support 26 is then retracted outwardly, whereupon the plate will seat progressively from right to left against the arch 20. With the 'supports 25 and 26 fully raised and retracted outwardly, eplate will be held immovably against the arch 20. 5

' In accordance with the invention, the interio r surface of the plate 23. is finished and the tension lockup pockets 66 are formed'in the plate while the plate is held in the supporting arch 20.

To provide for relative linear feeding movement between the plate-supporting arch 20 and the boring-and milling. mechanism 69A, the plate-finishing machine frame 22 is formed with a pair of guideways 70 (Fig. 2)

extending horizontally and parallelto each other on opposite sides of the machine for the greater part of the length of the machine. The guideways 70 are arranged in parallel relation to the cylindrical axis of the arch 20. Support for the boring and milling mechanism 69A is proivided by a tool carriage or movable frame 72 having :guides 73 in slidable engagement with the guideways 70.

' For the purpose of finishing the cylindrically curved are mounted in the g In the illustrative embodiment, these operations are carried out by means of a combination boring and milling mechanism 69A.

The plate 23 is pressed against the arch 20 at points axially in advance of and just behind the boring head 76, by means of two roller heads and 80A (Fig. 4), one at either side of the boring head. Each roller head is fitted with a plurality of spherically curved rollers 81 which are spaced apart angularly so as to engage the longitudinally extending ribs 64A on the printing plate 23. Each of the rollers 81 is biased radially outwardly by a heavy spring 82 engaging a pillow block 82A in which the roller is journalled. The outward pressure exerted by the rollers acts to smooth out any irregularity inthe plate 23. The roller head 80A is supported integrally with the frame 72, but the roller head 80 is secured to the frame by means such as cap screws 80B.

The boring head 76 is preferably driven at a high speed so that a fine finish will be obtained on the interior surface 62 of the plate 23. For this purpose, a motor (Fig. 1) is mounted at one side ofthe frame 22 and is arranged to drive a longitudinal shaft 91 by means of a belt 92 (Fig. 2) and suitable pulleys. Means are provided for driving the boring head shaft 75 from the shaft 91, regardless of the axial position of the boring head 76. To this end, the shaft 91 is splined or otheiwise slidably connected to a pulley 93 which isslid along the shaft 91 by a'bra'cket 94 (Fig. 1) depending from the movable carriage 72. A belt 95 is employed to connect the pulley 93 to a pulley 95 mounted on a shaft 96 which is journalled in the carriage 72. Fixed to the shaft 96 is a pinion 97 meshing with a gear 98 fixed to the'boring head shaft 75. A housing 99 en- -closes the gears 97 and 98.

1 Themovable frame or carriage 72 may be fed axially "by means of a'motor' 100 (Fig. 2) mounted on the machineframe 22 and belted to a pulley'101 carried by a longitudinally extending feed screw 102 whichis journalled in the frame 22. A nut or internally threaded sleeve 104, fixed to the frame 72, is in threaded engagement with the feed screw 102 so that rotation of the screw will move the frame 72 axially along the guideways 70. The motor 109 is reversible and thus may be employed to drive the frame or carriage 72-ineither'axial direction. Limit switches 105 and 106- (Fig. 1) be provided in' the circuit of the motor 100 to'limit th range of'axial movement of the tool carriage 72.

To cut the tension lockup pockets 66 in the plate 23 the tool carriage 72is equipped with milling means in the form of a pair of milling heads'1'07 '(Fig. 3.) which are movable in'a direction transverse to the direction of feeding movement. "'In this instanee eaeh of the milling heads 107 comprises a housi ngfllb' having a pair of trunnions or stub shafts 116 'andIIGA (Eig. 10) mounted in respective anti-friction bearings 117 and 118 so that the milling headsI'107 will be s'wingable laterally of the direction of feeding movement. The

trunnion 116A is hollow and serves as a supportlfor a drive shaft 109 journa'lled on an anti-friction bearing 119. Fixed to the shaft 109 is a gear 108 meshing with the boring head gear 98. The opposite end of the-shaft 109 carries a bevel gear 110 which meshes with a bevel gear 111 fixed to a milling spindle 112 (Fig. 8),mounted on anti-friction bearings 114 in the housing'115 and extending radially relative to the axis of the drive shaft 109. The outer end of themilling spindle 112'extends beyond the housing 115 and is adapted to receive a main milling cutter 113 and an auxiliary chamfering cutter 113A. In cross section, the main cutter 113 matches the profile of the tension lockup pockets 66. e

To provide for moving the milling heads.107 outwardlyand inwardly as an incident to the linear feeding movement between the tool carriage 72 and thearch 20, the housing 115 on each milling head 107 isprovided with a depending arm adapted to be rocked backandforth by means of a mm 124' (Fig. 7) fixed to the frame 22. The earn 124 is engaged by a follower roller 122 mounted on. a slide 121,-which is connected to the arm 12% by means of a clevis "125 carrying a screw'rod 126 threaded into the slide. A pivot'127 is employed'to connect the clevis 125 to the arm'120. It will be evident that the'screwrod 126' provides an adjustment of the position of the milling head 107.

In the illustrated construction, the cam 124 comprises a main slot or cam track 139and a return track 131 adapted to control the follower roller 122 and thereby to rock the milling head 107 so that the axially spaced pockets 66 wilt be formed in the plate. As'the tool carriage 72 is fed forwardly (downwardlyin Fig. the follower roller 122 will' be advanced along the track 130 and, by virtue of the shape of the track,'will'be moved laterally to form axiallyspaced pockets of the required depth and at the desired longitudinal points along the axial length of the plate 23. Near the end of the range of feeding movement of the tool carriage 72, i the follower 122 will displace a pivoted switch 132 and thereby enter the end of the return track 131, whereupon the switch will be spring-returned to'its normal position as'shown in Fig. 7. During the reverse axial movement of the tool carriage 72, the follower 122 will travel in the return track 131 untilthe follower reaches a star switch 133, which will be rotated as the follower enters the main'track 13d and progresses into a common extension 135 of the tracks 130 and131. By means of a detent spring 136, the star switch 133 is-held against retrograde movement so that the follower 122will enter the main track 130 when the tool carriage 72 is again fed forwardly.

The milling heads 167 are locatedimmediately adjacent the roller head 50A so that theplate will be pressed firmly against the arch 20 as the tension lockup pockets 66 are being milled by the cutters 113 and113A. It will be noted that the milling heads 107 and the boring head 76 are on opposite sides of the roller head 80A.

The pitch of the lead screw 102 and the rotary speed of the cutter bits 77-may be so related that the interior surface 62 of the plate 23 will be accurately finished on a single pass of the boring head '76. During this pass, all of the plate hook recesses 66*are formed in the plate 23. Thereafter, the boring head and the milling heads may beidly withdrawn-in the opposite axial direction.

When the interior'of the plate 23 has been fully finished, the plate clamping lever 54 may be returned to its original position so as to drop the plate 23 to its lowermost position, whereupon the plate maybe removed from the arch 20. Means are preferably provided for automatically removing the plate 23. from thearch 20 the interior of the finished plate 23. i The height of the saddle 140 is such that it will carry the plate 23 clear of the supports 25 and 26, after the cams 39 have been rotated so as to return the supports 25 and 26 to their normal inoperative position. Thus, the finished plate will be deposited on the arcuate saddle 140 and will be carried to the unloading station C when the carriage 72 is returned to its original position.

While the specific control circuits do not form a part of the present invention, it will be understood by one skilled in the art that suitable switches are provided for starting, stopping and reversing the feed motor 100 to cause the forward and reverse travel of the axially movable carriage 72, as well as starting and stopping the motor 30 which drives the boring and milling heads. In addition, suitable signal devices such as signal lights, may be provided for indicating that the plate is securely held for finishing, has been finished, and that the machine is ready to receive another plate.

While the operation of the plate-finishing machine will assess? be apparent from the foregoing description, thefollowing brief summary 'will'be helpful. A stereotypeplate to be finished "is deposited at. the receiving station A with the straight edges of the plate-resting-onithe-'plate-supporting le'dges24. Nextgthe plate.23 is'slid ontothe plate supports 25-and 26 at the finishing station B,'with the plate supports'being' in their loweredpo'sition. To clamp the plate 23 against the'archlththe lever 54 is swung manually so :as to raise the plate supports 25 and 26. The plate-clamping mechanism 24A is'arrangedso that the plate supports 25 and '26 are movedinwardly toward each other at'the same time as they-are being raised. Inthis way,-the plateis pinched or compressed diametricallyso that it may freely enter: the arch-20 without scuffing action onthe printing surface.

With the plate 23' held against the arch 20, 'the=tool carriage 72 may be fed axiallyiof the-arch'by starting the 1 feed motor 100', which will rotate the feedscrew102 and terior plate surface 62 will be finished toia' true CYIiIIdIi-r cal shape .by the boring head 76. iDuringtheYboring operation, the platewill be pressed radially against the arch 20 by the rollers 81 on the roller heads. and.80A. Theboring head 76;'is drivenby the motor90. More specifically,'.the motor .drives the spline Shaft "91 through the medium of the belt 92, and the sliding pulley 93 on the spline shaft in turn.drives the pulley 95 on the shaft 96, the pulley. 93 being moved alongthe spline shaft by the bracket 94 on the carriage 72. 'The'pinion97' on the shaft 96 drives the gear 98 on the boring head shaft 75. As the boring head '76 finishes the interior surface 62 of the plate,'the tension lockup pockets 66 are-cut in the interior surface of the plate by the milling' heads 107. These heads 107 are driven by the gears108 which mesh with the gear 98 on the boring head shaft'75. The gears 108 drive the milling cutters 113 .and113A.on the milling spindle 112, through theme'diumoftheshaft 109 and the bevel. gears 11! and 111.

The length and axialspacingofnthe pockets. 66 are. determined by the conformationsof the vmainacam tracks in the cams 124. As the follower rollers122are fed along thecam tracks130, the milling heads'107, are alter nately rocked outwardly and inwardly .on the trunnions 116 and 116A. Accordingly, the 'millingicutters are movedinto stock removing engagement with the interior .of the plate during successive portionsofitheraxial feeding movement. During the subsequentreturn movement of the carriage 72, the follower. rollers traverse the return tracks'131 so that the milling cutters will. be withheldfrom the plate 23. 'Therollerheads 80 and 80A cooperate with the milling heads 107 by "holding the plate 23closely against the arch 20 so that the pockets formed by the milling heads will be accurately formed and located.

When the boring and milling heads have completed their finishing operations, the clamping "lever'54 is swung so as to lower the plate supports 25 and 26 and thereby disengage the plate 23 from the arch 20. The plate comes to rest on the saddle 140, mounted-on the carriage 72, and hence is carried axially out of'the arch to the delivery station C, when the carriage 72 is retracted to its initial position. The plate may then be removed manually from the saddle so that finishing operations on another plate may be commenced.

The plate-finishing machine is fully capable of finishing stereotype plates at a rate well in excess of two plates per minute. The exact rate will depend upon the skill of the operator. This unusual speed of operation, as well as the high accuracy of the final product, is the direct result of boring the plate and milling the tension lockup pockets in a single pass, while the plate is held in a single plate support.

I claim as my invention:

1. A machine for finishing cylindrically curved print .ing'plates, comprising, incombination, plate-supporting means for holding a plate, tool-supporting means adjacent said plate-supporting means for effectiverelative linear feeding movement between said plate-supporting and tool-supporting means in a direction parallel to the cylindrical axis of the plate, boring means mounted on said tool-supporting means for rotation about the longitudinal axis of the plate for progressively finishing the interior surface of the plate during said feeding movement, milling means mounted on said tool-supporting -means for rotation about an axis perpendicular to the axis of the plate, a -source of motive power, common means on said tool, supporting means coupled to said powersource for simultaneously rotating said boring means and said :milling means about their respective axes, and means operative as an incident to said feeding movement for moving said milling means laterally relative to the direction of said: feeding movement into and then out of milling engagement with the plate adjacent its straight edges to cut axially spacedtension' lockup pockets therein.

1 plurality of movable rollers biased radially outwardly for pressing the plate against said plate-supporting member during said linear feeding movement, a boring head adjacent said roller head on one side thereof and journalled on said tool-supporting means about a rotary axis coinciding with the cylindrical axis of said plate-supporting member for progressively finishing the inner surface of the plate during said linear feeding movement, said roller head insuring substantially true concentricity between the inner surface finished by said boring head and the outer surface of the plate, a milling head mounted on said tool-supporting means adjacent said roller head on the other side thereof, said milling head having a milling cutter mounted for rotation about an axis of which is perpendicular to the axis-f the plate, and means operable as an incident to said linearfeeding movement for moving said milling head transversely relative to the direction of feeding movement into and then out of -milling engagement with the plate adjacent a straight edge thereof for cutting axiallyspaced tension lockup pockets therein, said roller head insuring accurate location of the pockets.

3. A machine for finishing the undersides of cylindrically curved printing plates, comprising, in combination, plate-supporting means for holding a printing plate, tool-supporting means, means for effecting relative linear feeding movement between said plate-supporting memher and said tool-supporting means in a direction parallel to the cylindrical axis of the plate, a boring head having a shaft journalled on said tool-supporting means with the axis of said shaft coinciding with the cylindrical axis of the plate, so that said boring head will progressively finish the interior of the plate during said linear feeding movement, a pair of drive shafts journalled on said toolsupporting means and extending parallel to said boring head shaft on opposite sides thereof, said drive shafts being symmetrically arranged below the edges of the plate, means for driving said boring head shaft and said drive shafts in common including a gear mounted on said boring head shaft and meshing with a pair of gears mounted on said drive shafts, a pair of milling heads swingable about the axes of said respective drive shafts and including milling spindles extending at right angles thereto, bevel gears connecting said spindles to said respective drive shafts, and means operable as an incident to said linear feeding movement for swinging said milling heads outwardly and then inwardly into and out of stock removing engagement with the plate to cut axially spaced tension lockup pockets in the underside of the plate adjacent'its straight edges.

4. A machine for finishing the undersides of cylindrically curved printing plates comprising, in combination, plate-supporting means for rigidly holding a printing plate with its underside exposed, a carriage and means to drive the carriage along a path adjacent the underside of said plate, a shaft journalled onsaid carriage in alinement with the plate axis, means including a milling cutter for cutting tension lockup pockets into the underside of said plate along the straight edges thereof, said cutter eing mounted on said carriage for rotation about an axis which is perpendicular to and spaced from said shaft, common driving means on said carriage for rotating both said shaft and said cutter, a boring arm fixed to said shaft and supporting a boring cutter at its end, and means operable as an incident to axial movement of the carriage for moving said cutter into and out of milling engagement with the plate so that movement of the carriage past the plate is effective both to cut tension lockup pockets and to progressively finish the inner plate surface to a true cylindrical form.

References ited in the file of this patent UNITED STATES PATENTS

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