US3478557A - Tube reducing machine - Google Patents

Description

Nov. 18, 1969 A. F. TREMBLAY TUBE REDUCING MACHINE 5 Sheets-Sheet 1 Filed July 28, 1967 .Y R T mL T E A WE fi F T H E mm A Nov. 18, 1969 A. F. TREMBLAY 3,478,557

TUBE REDUCING MACHINE Filed July 28, 1967 5 Sheets-Sheet 2 ALBERT E T REMBLAY.

ATTYS,

Nov. 18, 1969 A. F. TREMBLAY TUBE REDUCING MACHINE 5 Sheets-Sheet 5 Filed July 28, 1967 ATTYE'.

Nov. 18, 1969 A. F. TREMBLAY 3,478,557

TUBE REDUCING MACHINE 5 Sheets-Sheet 4 Filed July 28, 1967 I INVENTOR. ALBERTF IHEMBLAK QMQW ATTYS.

United States Patent US. Cl. 72-189 13 Claims ABSTRACT OF THE DISCLOSURE A tube reducing machine is provided which has large diameter dies and die holders supported in a stationary frame. The machine includes relatively simple components for movably' supporting the die holders relative to the frame of the machine and yet enabling the die holders to move with forward and rearward coordinated strokes without the necessity of moving the frame back and forth. The die holders carry gear segments which are engaged with one another to synchronize movement thereof, with one of the gears also being engaged with a gear rack to further control movemnt of the die-holders. The tube reducing machine also has a unique drive arrangement by means of which only one of the die holders is driven, with a linkage connection arranged between the die holders to move the second holder with the first. The dies of the machine also are adjustably mounted in the die holders so as to be accurately positioned, adjusted for wear, and adjusted to produce a precise final dimension of the tube.

This application is a continuation-in-part of my copending application Ser. No. 459,661 filed on May 28, 1965, now Patent No. 3,357,223.

This invention relates to a tube reducing machine having improvements particularly in the supporting arrangement for the die holders and in the drive therefor.

Tube reducing machines generally have included a pair of mating die rolls mounted in a reciprocating frame or saddle supported for reciprocation in a path parallel to the axis of the tube being rolled and reduced. Such saddles were necessarily massive to withstand the pressures involved in the cold forming operation, and the power required to reciprocate the saddles was substantial. Also the number of strokes per unit of time which could be achieved was quite limited.

For some tube reducing machines heretofore proposed, relatviely large diameter dies have been suggested which were rocked back and forth through relatively small angles and held by a stationary frame. However, with the manner in which these rolls were supported and driven, a substantial amount of sliding or skidding contact occurred between the dies and the tube. This resulted in rapid die wear as well as skid marks on the surfaces of the finished product. A considerable amount of heat also was produced with consequential loss of power.

While certain tube reducing machines have been proposed in the art which support and rock the dies back and forth in a manner to produce a relatively small ice amount of sliding, such machines have incorporated unduly complicated supporting and drive mechanisms which have rendered the machines costly and increased the maintenance problems thereof. Further, the dies of such machines have engaged the tube being reduced during only one stroke of the dies, being separated from the tube upon the return stroke. Of necessity, this substantialy reduced the production rate of the machines.

The present invention relates to an improved tube reducing machine having many advantages over those heretofore known. The new machine incorporates a pair of large diameter dies mounted in a stationary frame, rather than a reciprocating one, and with simplified supporting components for the dies and die holders. The components, even though uncomplicated, are designed so that the rolls have little tendency to slide on the tube. The machine also employs an arrangement for coordinating the rocking movements of both die holders relative to one another as well as coordinating them relative to the frame to maintain close control over their movements. The drive arrangement for the die holders of the new machine also is unique. Only one of the die holders is directly driven while the second is indirectly driven through a novel linkage arrangement connected with the first die holder. With this, there is no necessity of precisely coordinating drive mechanisms for reach of the die holders as has heretofore been the case. The dies of the new machine preferably are recessed slightly in the die holders so that the dies never come in contact with one another. This substantially reduces damage to the dies which are of hardened metal and are subject to breakage.

It is, therefore, a principal object of the invention to provide an improved tube reducing machine having many advantages over those heretofore known.

Another object of the invention is to provide a tube reducing machine with simplified supporting components for die holders thereof which enable the dies to function with a minimum of sliding.

A further object of the invention is to provide a tube reducing machine with a drive arrangement which enables operation of the die holders to be closely coordinated.

Still another object of the invention is to provide a tube reducing machine with an improved arrangement for synchronizing the strokes of the die holders.

Many other objects and advantages of the invention will be apparent from the following detailed description of a preferred embodiment thereof, reference being made to the accompanying drawings, in which:

FIG. 1 is a fragmentary side view in elevation of a tube reducing machine according to the invention, with parts broken away, and of apparatus for supporting, feeding, and turning a tube being reduced;

FIG. 2 is a fragmentary plan view of the apparatus of FIG. 1;

FIG. 3 is a fragmentary view in vertical cross section, on a greatly enlarged scale, taken along the line 33 of FIG. 1;

FIG. 4 is a side view in elevation of the tube reducing machine of FIGS. 1 and 3, on a slightly smaller scale than FIG. 3, with parts broken away and with parts in cross section;

FIG. 5 is a right end elevational view of the machine of FIG. 4, with certain parts removed;

FIG. 6 is an enlarged, fragmentary view in vertical cross section, taken along the line 6-6 of FIG. 3;

FIG. 7 is a right end view of the components of FIG. 6; and

FIG. 8 is a diagrammatic view showing various lengths and relationships between several components of the machine embodying the invention.

Referring to FIGS. 1 and 2, a tube reducing machine 10 embodying the invention is shown with conventional apparatus for feeding and turning a tubular billet in coordination with the operation of the tube reducing machine. This is accomplished through an indexing mechanism 12 which coordinates feeding and turning mechanism with the operation of the machine 10. The mechanism 14, through a gear connection 16, is synchronized with a turning mechanism 18 so that the tube is turned at both ends of the stroke of the machine but is fed longitudinally only at one end of the stroke. The mechanisms 14 and 18 are known in the art and will not be discussed in detail. A billet 20 usually is from about eight to sixteen feet long prior to being reduced. In a typical example, the billet 20 initially has a 3 /2 inch diameter which is reduced to 2 /2 inches along with a reduction in the thickness of the Wall of the tube from /2 inch to 4 inch by the time it emerges from the machine 10. The tube can be fed axially or longitudinally about 4 inch each time the die components of the machine 10 reach the end of their forward stroke, and the tube can be rotated typically forty degrees each time the die components reach the end of their rearward stroke. Depending upon the particular operation, the feed of the tube can vary from about A inch to about one inch, while the rotation can vary from approximately twenty degrees to sixty degrees. A mandrel is employed within the tube in the conventional manner to control the inside diameter.

Referring more particularly to FIGS. 3-5, the tube reducing machine 10 includes a stationary frame 22, an upper die assembly 24, and a lower die assembly 26. The stationary frame 22 includes a drive housing or base 28, side frame members 30 and 32, upper corner posts 34, and an upper frame member 36.

The upper die assembly 24 has an upper axle or backup roll 38 supported by the upper frame member 36 through ears 40 and 42 and caps 44 and 46. Because the axle 38 is urged upwardly during a tube reducing operation, relatively little stress is placed on the ear caps 44 and 46. Large roller bearings 48 and 50 are rotatably mounted on spaced cylindrical portions 52 and 54 of the axle 38. A connecting link 56 has upwardlyextending yokes 58 and 60 rotatably received on the roller bearings 48 and 50 and provided with suitable covers 62 and 64 extending around the bearings 48 and 50. It is not necessary for the yokes 58 and 60 to extend completely around the bearings 48 and 50 since most of the force on the link 56 is in an upward direction. However, the covers 62 and 64 serve to retain the yokes 58 and 60 on the bearings 48 and 50 at the ends of the strokes, when little or no pressure may be applied to the dies. The link 56 further includes a pair of outboard cylindrical portions 66 and 68 which carry additional roller bearings 70 and 72. Extensions 74 and 76 beyond the cylindrical portions 66 and 68 receive bearing covers 78 and 80 which also extend upwardly around the bearings 70 and 72. Further, the link 56 has a cylindrical projection 82 projecting beyond the extension 76 to receive an actuator link which will be discussed subsequently.

An upper die holder or die block 84 is located below the connecting link 56 and has upper yokes 86 and 88 received around and rotatably engaged with the roller bearings 70 and 72. The outer covers 78 and 80 are affixed to the die holder 84 and may aid in supporting the die holder from the link 56, particularly during end portions of the strokes of the dies. The die holder 84 extends through an included angle of about thirty degrees and carries a gear segment 90 at one side which meshes with a gear segment 92 constituting part of the lower die assembly 26. In turn, the lower gear segment 92 meshes with a gear rack 94 carried by the frame member 30. This assures coordinated movement of the die holders of the assemblies 24 and 26 and, at the same time prevents possible slipping of both dies with respect to the tube being reduced and with respect to the frame. This feature of the tube reducing machine contributes to the overall quality of the product.

The die holder 84 has a central, longitudinal groove or recess 96 in which is carried an upper die or die insert 98. The face of the die insert 98 is arcuate, similar to that of the die holder 84, but extends through an angle of only about twenty-three degrees compared to about thirty-two degrees for the die holder. The face of the die 98 preferably is recessed slightly from the face of the die holder 84 by about & inch which enables much of the pressure to be applied between the die holders rather than the dies. The slight clearance does not affect the shape of the tube being reduced because the die has flared edges extending away from a semicylindrical surface so that the edge portions of the die do not contribute to the forming of the metal even if the dies were in contact. A forming surface 100 of the die is of substantially semicircular cross-sectional shape with the radius at the forward end (left end as shown in FIGS. 4 and 6) exceeding that at the rear or right end. At the forward end, the radius of the die surface 100 is substantially equal to the radius of the tube or billet to be cold formed and, along a portion of the opposite end is substantially equal to the final desired radius of the tube.

The die 98 is adjustably and accurately located in the die holder groove 96 by a mounting assembly shown in FIG. 6, which enables vertical, transverse, and longitudinal adjustment of the die insert. For vertical adjustment, an upper shim 102 is located at the upper wall of the groove with the die held thereagainst by suitable bolts 104. For transverse adjustment, the groove is provided with a precisely located longitudinal, vertical surface with the die 98 held thereagainst by a side wedge 106 which is adjusted longitudinally by an adjusting bolt 108 and a stop bolt 110. For longitudinal adjustment, the die has slanted ends which are engaged by two end wedges 112 and 114 vertically adjustable by bolts 116 and 118. A shim 120 is located between the wedge 114 and an end wall 122 of the die holder 84 while a back-up bar 124 is located behind the wedge 112 and is fastened to the die 98. The adjustments compensate for wear of the die 98 and also enable close control over the final tube diameter.

Referring to FIGS. 3-5, the lower die assembly 26 includes components basically similar to the components of the upper assembly 24, and will be discussed in less detail. A lower die or die insert 126, which includes a generally semicircular die surface 128 similar to the surface 100 of the die 98, is held in a die holder 130 and is recessed therein about inch to provide a slight spacing of about inch from the die 98. The die holder 130 is substantially identical to the die holder 84 and, as discussed before, carries the gear segment 92 which engages both the gear segment 90 and the gear rack 94 to assure coordinated movement with the die holder 84 and also to prevent slipping of both dies relative to the tube or the frame.

The die holder 130 has a pair of downwardly-extending yokes 132 and 134 which are rotatably supported on a pair of roller bearings 136 and 138 with covers 140 and 142 extending therearound and aflixed to the die holder 130. The roller bearings 136 and 138 are mounted on cylindrical portions 144 and 146 of a lower connecting link 148. The link 148 has downwardly-ex- 5 tending yokes 150 and 152 supported on roller bearings 154 and 156 with covers 158 and 160 extending therearound. The bearings 154 and 156 are mounted on cylindrical end portions 162 and 164 of a lower axle or backup roll 166.

The axle 166 has a central cylindrical bearing portion 168 which is rotatably mounted on a bearing block 170 having a cap 172. The block 170 is supported on an adjusting wedge 174 which is longitudinally movable by an adjusting bolt 176 (FIG. 4) to place a predetermined preload on the die holders. A substantial pre-load force is required to prevent separation of the die inserts. For example, for a 3 /2 inch diameter tube with a /2 inch wall thickness, a force of at least 300,000 pounds is required, depending upon the type of material being processed, to reduce the outside tube diameter to 2%. inches with a inch wall thickness. The bearing block and bearing are further supported through end supporting blocks 178 and 180 (FIG. 4) and shim plates 182 and 184 to provide a broader base for the machine components during operation thereof.

Further support for the die components of the lower assembly can be provided through two cam followers or rollers 186 and 188 rotatably connected by axles 190 and 192 to lower corner portions of the lower die holder 130. Associated with the cam rollers 186 and 188 are two cam plates 194 and 196 suitably aflixed to the frame 30 and contoured such as to closely follow the paths of the rollers 186 and 188 during the rocking movements of the die holders 84 and 130. Actually, the contours are such that the cam rollers usually do not contact the cams during most of the rocking movements but are primarily intended as back-up supports, if necessary, at the ends of the strokes of the die holders. At the ends of the strokes, less of the weight and forming pressure tends to be carried directly through the connecting links, bearings, and back-up rolls.

Referring now to the drive arrangement for the machine 10, preferably only one of the two die assemblies 24 and 26 is driven, with the other one of the die assemblies then driven through a connection between the assemblies. This eliminates the necessity of coordinating separate drives as well as reduces the costs of the drive elements and the overall space requirements for the machine. As shown in FIGS. 3-5, the upper die assembly 24 has a side actuator link 198 having an intermediate opening rotatably receiving the link projection 82 with the actuator link having an upper opening pivotally receiving a projection 200. The lower end of the link 198 is pivoted to a drag link 202 which is pivotally connected to an ear 204 of a slide 206. The slide 206 is received on a slide bar or way 208 and has a flange 210 affixed thereto which is received in a groove 212 in the slide bar 208. Below the slide bar 208, the slide 206 has an ear 214 which is pivotally connected to a lower drag link 216. The lower drag link is connected to a lower actuator link 218. This link, at an intermediate point, receives a projection 220 of the link 148 and, at a lower end, receives a projection 222 of the axle or back-up roll 166. This drive connection enables one of the die assemblies 24 and 26 to be driven by the other and yet enables the die holders to rock back and forth and even to separate slightly during the pivotal movement of the actuator links 198 and 218.

In the specific embodiment shown, the lower die assembly 26 is driven and for this purpose, the lower die holder 130 has a pair of forwardly extending arms 224 to which are pivotally connected a pair of crank arms 2216 (see FIGS. 4 and These, in turn, are connected eccentrically to gears 228 which are driven through gears 230, a drive shaft 232, and a sheave 234 connected by belts 236 to a suitable motor 238.

By employing the proper dimensions for the connecting links 56 and 148 and the die holders 84 and 130, the dies can be driven back and forth through their strokes and be maintained under the proper pressure without moving the supporting frame 20 relative to the tube and with substantially no slipping. Referring to FIG. 8, this result is achieved by designing the supporting links and die holders so that the arc of the axis of the bearing portion of the connecting link 56, which arc is produced as the link 56 pivots around the back-up roll 38, is superimposed on part of a prolate trochoidal curve which would be formed by a point corresponding to the same axis of the link during rotation of the die insert 98. As long as the arcuate path of the link axis is substantially superimposed on the prolate trochoidal curve, the die insert 98 will roll along a straight line without any transverse movement of the roll 38 or the frame 22. The

same is equally true for the lower connecting link and die holder. It may be noted that the diameter of the die and die holder always exceeds the distance from the meeting die holder faces to the pivotal connection of the connecting link and holder as Well as to the pivotal connection of the connecting link and upper frame.

By way of a specific example, in order to achieve a stroke length of approximately 26 inches with the dies 98 and 126 having a radii R1 of 60 inches, it is necessary that they rotate through an angle of 23. By positioning the axis of the bearing portion of the lower end of the link 56 at a point 36 inches from the center of rotation of the die 98, with the distance D1 then being 24 inches, and by making the effective length of the link 58 16% inches long so that the radius R2 is 16% inches, the desired result is achieved, namely that the are formed by the connecting link axis will be substantially superimposed on the prolate trochoidal curve through an arc of 11.5 on each side of the vertical. Beyond approximately ll.5, the arc of the link axis will deviate above the prolate trochoidal curve and the pressure of the dies 98 and 126 will diminish; consequently, the dies will separate upon continued angular movement of the links. Of course, the various factors involved such as stroke lengths, link lengths, angles, etc. will vary for each application and, according to the circumstance, it may be desirable to start with other given dimensions rather than stroke length as was done in the above example. The angular and length relationships of the upper die assembly are equally true for the lower die assembly 26.

The above discussion suggests that the arc of the lower axis of the link 56 will be directly superimposed on part of the prolate trochoidal curve formed by the same axis or point during the die stroke. Actually, however, the two curves will not be strictly superimposed and it is not essential that they need be. It is important, though, that the arc and the curve will be superimposed or cross one another at the completion of the forward end of the stroke of the dies since this is Where the rear end portions of the dies 98 and 126 determine the final diameter of the tube. The die surface does not taper completely from one end of the die 96- to the other, but the last two or three inches of the die, corresponding to the last two or three degrees of the stroke, are semi-cylindrical and do not taper. It is at these portions of the stroke and the die where the two curves must be substantially identical insofar as the distance from the axis of the axle 38 is concerned, to assure accurate and true dimensions of the finished reduced tube.

Under the specific conditions discussed, with the radius R2 of the link being 16% inches and with the complete die stroke extending through an arc of 23, the arc and the prolate trochoidal curve must intersect at a point located 16% inches from the axis of the axle 38 and 11.5 from a center line through the axle 38, this point being marked P in FIG. 8. The distance from the prolate trochoidal curve to the axis of the axle 38 will be less than the radius R2 for angles between 0 and This is of little consequence, however, since it merely affects the intermediate diameter of the tube being reduced at portions between the original diameter and the final reduced diameter and does not affect the final tube diameter.

By designing the linkages to relieve the die pressure at the end of each stroke, when the distance from the axle axis to the lower link axis is less than the distance from the axle axis to the corresponding point of the prolate trochoidal curve, the tube can be fed longitudinally and rotated at the appropriate ends of the strokes. In the example discussed above, the dies can be moved through a 26 are with pressure relieved as the dies move beyond each end of a 23 arc to provide the proper clearance, about A; inch in this instance, for axial and rotational movement of the tube. Otherwise, the dies 98 and 126 can be machined so that relief is achieved at the ends of the strokes to the feeding and rotation of the tube, by slightly flaring the ends of the die recesses 100 and 128.

Various modifications of the above described embodiment of the invention will be apparent to those skilled in the art, and it is to be understood that such modifications can be made without departing from the scope of the invention, if they are within the spirit and the tenor of the accompanying claims.

I claim:

1. A tube reducing machine comprising a stationary frame, a pair of opposed die holders, a large diameter die carried by each of said holders, link means pivotally connected to the upper die holder and pivotally connected to an upper portion of said stationary frame for supporting said upper die holder and its die by the upper portion of said frame, said link means guiding the center of its pivot connection with said upper die holder in an arcuate path lying substantially on a portion of a prolate trochoidal curve traced by the pivot center as the surface of the upper die holder rolls along a straight line, second link means pivotally connected to the lower die holder and pivotally connected to a lower portion of said frame for supporting said lower die holder and its die by the lower portion of said frame, said second means guiding the center of its pivot connection with said lower die holder in an arcuate path lying substantially on a portion of a prolate trochoidal curve traced by the pivot center as the surface of the lower die holder rolls along a straight line, and means carried by said die holders and engageable with one another to coordinate the movement of said die holders and said dies.

2. A tube reducing machine according to claim 1 characterized by actuator link means movable with said upper link means and lower actuator link movable with the lower link means, and means connecting said actuator links.

3. A tube reducing machine according to claim 1 characterized further by cam means mounted on said frame, and cam follower means carried by said lower die holder for engaging said cam means during a portion of the movement of said lower die holder.

4. A tube reducing machine according to claim 1 characterized by the radii of said upper and lower die holder surfaces exceeding the distance from said surfaces to the pivotal connections of said link means and said frame.

5. A tube reducing machine comprising a frame, a pair of opposed die holders having opposed arcuate faces, cooperating dies carried by said die holders, means movably connecting said upper die holder to an upper portion of said frame, means movably connecting said lower die holder to a lower portion of said frame, means for rocking said die holders in forward and rearward strokes with the faces of said die holders meeting along a straight line during the forward and the rearward strokes, means on each of said die holders engageable with one another to coordinate movement of said die holders during said forward and rearward strokes, and additional means carried by said frame and engageable with one of said coordinating means to minimize the possibility of both of said die holders slipping with respect to said frame.

6. A tube reducing machine comprising a frame, a pair of opposed die holders having opposed arcuate faces,

cooperating dies carried by said die holders, means movably connecting said upper die holder to an upper portion of said frame, means movably connecting said lower die holder to a lower portion of said frame, means for rocking said die holders in forward and rearward strokes with the faces of said die holders meeting along a straight line during the forward and the rearward strokes, said rocking means comprising means for rocking one of said die holders and means connected between said die holders to cause said one die holder to move the other die holder.

7. A tube reducing machine according to claim 6 wherein said connecting means between said die holders includes a slide movable in a direction parallel to the line along which the die holder faces meet, and link means connecting the die holders with said slide.

8. A tube reducing machine comprising a frame, a pair of opposed die holders having opposed arcuate faces, cooperating dies carried by said die holders, means movably connecting said upper die holder to an upper portion of said frame including first link means pivotally connected to said upper die holder and pivotally connected to the upper portion of said frame, means movably connecting said lower die holder to a lower portion of said frame including second link means pivotally connected to said lower die holder and pivotally connected to the lower portion of said frame, an upper actuator link pivotally connected to both of the pivots of said first link means and extending downwardly toward the upper die, a lower actuator link pivotally connected to both of the pivots of said second link means and extending upwardly toward the lower die, means movably connected to both of said upper and lower actuator link to coordinate movement of said actuator links and said die holders, and means for rocking said die holders in forward and rearward strokes with the faces of said die holders meetin along a straight line during both the forward and the rearward strokes, including means for driving one of said die holders.

9. A tube reducing machine according to claim 8 wherein said means connecting said actuator links includes a slide, means for guidably supporting said slide along a path parallel to the straight line, and link means connecting said slide to each of said actuator links.

10. A tube reducing machine according to claim 9 wherein said means for rocking one of said die holders includes an arm affixed to one of said die holders, a crank arm pivotally connected to said arm, and means for driving said crank arm.

11. A tube reducing machine comprising a frame, a pair of opposed die holders having opposed arcuate faces, cooperating dies carried by said die holders, means movably connecting said upper die holder to an upper portion of said frame, means movably connecting said lower die holder to a lower portion of said frame, means for rocking said die holders in forward and rearward strokes with the faces of said die holders meeting along a straight line during the forward and the rearward strokes, arcuate gear segments carried by each of said die holders and engageable with one another to coordinate movement of said die holders, and a gear rack carried by said frame and engageable with one of said arcuate gear segments to minimize the possibility of both of said holders slipping with respect to said frame.

12. A tube reducing machine comprising a frame, a pair of opposed die holders having opposed arcuate faces, cooperating dies carried by said die holders, means movably connecting said upper die holder to an upper portion of said frame, means movably connecting said lower die holder to a lower portion of said frame, means for rocking said die holders in forward and rearward strokes with the faces of said die holders meeting along a straight line during the forward and the rearward strokes, two spaced cam followers carried by said lower die holder, and cams carried by said frame for engaging said cam followers and for aiding in supporting said lower die holder at portions of the strokes thereof.

13. A tube reducing machine comprising a stationary frame, a pair of opposed large diameter die holders, each of said die holders having a recess therein, a die having slanted end faces received in each of said recesses, a wedge at each end of said die and engageable therewith, means for adjustably connecting said wedges to the associated die holder whereby the Wedges can be moved in and out relative to the die holder to move the die longitudinally thereof to a predetermined position relative to the die holder, upper link means pivotally connecting the upper die holder to an upper portion of said frame, lower link means pivotally connecting the lower die holder to a lower portion of said frame, means for rocking said die holders together in forward and rearward strokes with said die holders meeting along a straight line which substantially symmetrically extends between said dieholders, the radii of the meeting faces of said die holders exceeding the distance from the meeting die faces to the axes of the pivotal connections of said link means and said frame.

References Cited UNITED STATES PATENTS Re. 12,516 7/1906 Briede 72189 2,118,224 5/1938 Pearson 72189 2,153,839 4/1939 Liebergeld 72-189 2,247,863 7/ 1941 Tiedemann 72--189 CHARLES W. LANHAM, Primary Examiner L. A. LARSON, Assistant Examiner

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