US2988938A - Control for rolling mill - Google Patents

Description

June 20, 1961 A. B. sHUcK ET AL CONTROL FOR ROLLING MILL 3 Sheets-Sheet l Filed May 24, 1960 Amwm En mm..

June 20, 1961 A B, SHUCK ET AL 2,988,938

CONTROL FOR ROLLING MILL Filed May 24, 1960 5 Sheets-Sheet 2 Fig-E af 76 a@ 78 3. es' A June 20, 1961 A. B. SHUCK ET AL 2,988,938

CONTROL FOR ROLLING MILL Filed May 24, 1960 3 Sheets-Sheet 5 TE-E @f4 l V United States Patent O 2,988,938 `CONTROL FOR ROLLING MILL Arthur B. Shuck, Wheaton, and William C. Shaw, Joliet,

Ill., assignors to the United States of America as represented by the United States Atomic Energy Commission Filed May 24, 1960, Ser. No. 31,504 3 Claims. (Cl. Sil-43) This invention relates to [the processing of materials in a controlled atmosphere, and more particularly, to the automatic handling of certain metals to be shaped in a rolling mill.

In Ithe rolling of plutonium, an inert isolated atmosphere is required, because of the toxicity of plutonium to the air to be breathed by workmen and because of the oxidation of plutonium in air at rolling temperatures.

The present invention involves automatic handling of metal between passes in a rolling mill, which makes it possible to carry out the rolling operations in a special atmosphere. In the rolling mill to which the present invention is applicable, ametal workpiece may be indexed by Abeing angularly shifted about its own axis between passes or by being shifted lengthwise of the rolls between passes. According to the present invention, a chuck that indexes a workpiece las just described is opened or closed in response to theV condition or relative position of feed rolls when the workpiece enters or leaves these feed rolls.

In the drawings:

FIG. 1 is a diagrammatic View illustrating the novel apparatus of the present invention;

FIG. 2 is a vertical Isectional showing the feeding rolls and gripper of the present apparatus;

FIG. 3 is an end view of the gripper, partly in section, taken on the line 3-3 of FIG. 2;

FIG. 4 is an end View of a head forming part 'of the gripper; and FIG. 5 is a developed View of the peripheral surface of the head.

With reference to FIG. 1, a workpiece (not shown) is fed repeatedly between upper and lower shaping rolls and 11 by means of two sets of upper and lower feed rolls 12, 13, 14, and 15. One set of feed rolls is to one side of the shaping rolls 10 and 11, and the other set, to the other side. Each set comprises a pair of upper and lower feed rolls 12 and 13, which are relatively near the shaping rolls 10 and 11, and a pair of upper and lower feed rolls 14 and 15, which are relatively far from the shaping rolls 10 and 11, i.e., adjacent the rolls 12 and 13 on the side thereof` away from the shaping rolls 10 and 11. In each set, the upper feed rolls 12 and 14 are interconnected by a yoke 16, which moves bodily upward from the horizontal position shown in FIG. 1 when the workpiece is between all the feed rolls, tilts clockwise when the workpiece lies only between the feed rolls 14 and 15, and tilts counterclockwise when the workpiece Y lies only between the feed rolls 12 :and 13.

Beyond the feed rolls 12, 13, 14, and 15, on the side therefrom away from ,the shaping rolls 10 and ,11, ylies a gripper 17, which is actuated either to grip or release the workpiece depending on the direction of its movement through the feed rolls, when the yoke 16 is tilted clock- Wise'because the workpiece is between only the rolls 14 and 15. Such `actuation of the gripper 17 is brought about by an electric switch 18, which is closed only by vclockwise tilting of the yoke .16. Closing of the switch Q18 supplies an electric current through lines 19 and 2t) hold the workpiece.

switch 2,1 is thrown, which direction is lin turn dependent l on the direction of movement of the workpiece `through the feed rolls 12, 13, 14, and 15.

Thus, when the workpiece is moving away from the shaping rolls 10 and 11 .through the left-hand set of feed rolls 12, 13, 14, and 15, the switch 18 is closed and ener-v gizes the solenoid 22, which shifts a valve 24 from the dotted-line position to the `full-line position. As a result, gas under pressure is supplied by a pump 25 through a line 24a and the valve 24 to the outer ends of cylinders 26, where it acts against pistons 27 to move them and their associated gripper elements 28 toward one another into engagement with the workpiece as it emerges from the feed rolls 12, 13, 14 and 15.

When the switch 21 is thrown in the opposite direction, so .that clos-ing of switch 18 energizes the solenoid 23, the latter moves the valve 24 from the full-line position to the dotted-line position, in which the pump 25 land the outer ends of cylinders 26 are connected to an exhaust line 29. As a result compression springs 3l) on the gripper ele* ments 28, move the gripper elements outward to release the workpiece. f

When the workpiece cornes from the feed rolls 12, 13, 14, and 15 into the gripper 17 and is held thereby, the gripper 17 and the workpiece are moved away from the feed rolls by a cylinder 32 and a piston 33 moving in the cylinder and connected to the gripper 17 through-a rod 34. The piston 33 is moved in the cylinder 32 by gas under pressure supplied -by the pump 25 through a line 35, a valve 36, and line 37 or line 38, depending on the position of the valve 36. The valve 36 is controlled by solenoids 39 and A40. When neither solenoid is energized, the valve -36 is positioned as shown, blocking flow of gas to both lines 37 and 38, because of the action of compression springs 41 against a partition 42.

When the switch 21 is thrown so that closing of switch 18 energizes solenoid 22, the valve 24, being brought to its full-line position by solenoid 22, supplies gas under pressure from the pump 25 to the cylinders 26 to make the gripper elements 28 engage the workpiece. At the same time, Ithe solenoid 39, being connected to the same side of the switch 21 as the solenoid 22, and in parallel therewith, through lines 43 and 44, is energized and shifts the valve 36 to the right of the position shown. As a result, gas under pressure goes from the line 35 through the valve 36 and the line 37 to the right end of the cylinder 32, and the left end of the cylinder 32 exhausts through the valve 36 and through an exhause valve 45 opened by a solenoid 46, connected in parallel with the solenoid 39 so as to be energized simultaneously therewith. When the solenoid 46 is no longer energized, the valve y4.5 is automatically closed. When the piston 33 reaches the left end of the cylinder 32, it opens a limit switch l48, deenergizing the solenoid 39. Thus the valve 36 is returned by the springs 41 to the position shown, and gas is no longer supplied against the right side of the piston 33 to move the piston leftward.

When the piston 33 is to be moved to the right, the switch 21 is closed to the side where the solenoid 23 lies. Incidentally, this closing of switch 21 does not energize solenoid 23, because the switch 1S is open, the workpiece not yet having reached the rolls 14 and 1S so as to tilt the yoke 16. The solenoid 23 being unenergized, the valve 24 remains in its full-line position, so that the pump 25 continues to supply gas against the pistons 27, and the gripping elements 2S continue to The switch 21 being closed as aforesaid, current is supplied to the solenoid 40 through lines 20, 49, and 50 independently of the open switch 18, Yand the valve 36 moves leftward from the position shown. As a result, gas under pressure is supplied from the` pump 25 to the left side of the piston 33 through lines 35 and 38,- and the right end of the cylinder 32 exhausts through the line 37. The valve 24 having stayedin the full-line position, the elements 28 continue to hold the workpiece, which is brought rightward to the feed rolls 12, 13, 14, and as the piston 33 is moved rightward by gas pressure. When the workpiece enters the feed rolls 14 and 15, the yoke 16 tilts clockwise, closing switch 18. As a result, the solenoid 23 is energized and shifts the valve 24 to the dotted-line position. Consequently, the pump 25 and the outer ends of the cylinders 26 are connected to the exhaust line 29, and thc springs 30 to move the gripper elements outward to release the workpiece, which may now continue through the feed rolls 12, 13, 14, and 15 to the shaping rolls 10 and 11. When the piston 33 reaches the right end of the cylinder 32, the piston Opens a limit switch 51, deenergizing the solenoid 40.

With reference to FIG. 2, the upper rolls 12 and 14 are journaled on shafts 52, which have their ends supported on two side plates 53, only one being shown, which, together with braces 54 interconnecting the side plates, constitute the yoke 16. The yoke 16 is tiltingly supported on a carriage 55 by a rock shaft 56, which extends through the carriage, the side plates being at opposite sides of the carriage. Tilting of the yoke 16 with respect to the carriage 55 is yieldingly resisted by four compression springs 57, only two being shown, which rest in recesses in the braces 54 and openings in the carriage 55, where the springs are adjusted by threaded stops 58, fixed by lock nuts 59. The carriage 55 is carried on the lower end of a vertical post 60, which may be adjusted by means, not shown, to accommodate workpieces of different diameter or thicknesses.

When, as shown in FIG. 2, no workpiece is between the feed rolls 12, 13, 14, and 15, rolls 12 and 14 are held in contact with rolls 13 and 15, respectively, by four compression springs 61, only two being shown, which rest in four openings in a retainer 62 spaced 90 from one another about a central opening 63 as a center in the retainer 62. The retainer 62 rests in a central depression in the carriage 55, a projection 64 on the carriage fitting in the opening 63 in the retainer 62. The lower ends of the springs 61 engage the carriage 55 in its central depression, and the upper ends of the springs 61 engage a thrust member 65. Between the thrust member and a head 66 on the post 60 is positioned a bearing member 67, which permits the post 60 to be rotated for vertical adjustment without involving the thrust member 65, which is held in the carriage 55 against rotation with respect thereto. The carriage 55 is retained on the post 60 by means of a collar 68, which is secured to the carriage 55 by screws 69 and engages the head 66 on the post 60. When the workpiece lies both between feed rolls 12 and 13 and between feed rolls 14 and 15, the yoke 16 and the carriage 55 move up together against the action of the springs 61 to the extent permitted by the clearance between the lower side of the thrust member 65 and the top of the retainer 62 and the central depression in the carriagev 55 and between the collar 68 and a shoulder 70 on the post 60.

The switch 18 consists of a contact 71 attached to the carriage 55 and a contact 72 in the form of a threaded member adjustably threaded into the yoke 16and secured by a lock nut 73. The switch 18 closesonly when the yoke 16 tilts clockwise with respect to the carriage 55 to make the Contact 72 engage the Contact 71.

Although FIG. l shows only two elements 28 for the gripper 17, there are actually six such elements 28, as will be seen in FIGS. 2, 4, and 5. The six elements 28 are arranged in three sets of two elements; the elements of each set being angularly displaced 60 and 120 from the elements of the other two sets and being axially displaced from the elements ofthe `other two sets along an axial opening 74 Vformed in an angularly shiftable block 4 75, which forms the cylinders 26 in which the pistons 27 are mounted; the two elements of each set being diametrally opposed and having the same location along the axial opening 74. Thus in the developed view of the peripheral surface of the block 75 in FIG. 5 the positions of the gripper elements 28 can be seen from the positionsvof the' associated cylinders 26. The long horizontal dimension of FIG. 5 represents 360, and the short vertical dimension represents displacement along the axis of the opening 74 in the block 75. Thus in the rst set A, cylinders 26 are seen to be 180 apart, being at the middle and in halves at the ends and at the same axial location. Likewise in each of the second and third sets B, and C the cylinders 26 are seen to be 180 apart from one another and at the same axial location along the opening 74 as one another, and to be 60 or 120 from the cylinders 26 of the other sets and at different axial locations along the opening 74.

As shown in FIG. 3, each gripper element 28 is formed in a shallow or flat V. When the six gripper elements 28 are projected into the same plane, they seem to overlap and approach one another much as the elements in the shutter of a camera. The six gripper elements 28 engage the workpiece at six diterent regions equally distributed about the workpiece.

Each gripper element 28 is wider than it is thick, as will be seen from FIG. 2 alone and from a comparison of FIGS. 2 and 3. The gripper elements 28 are slidably mounted in bushings 75a suitably shaped to prevent rotation of the gripper elements about their own axes. The bushings 75a are mounted in the block 75. The springs 30, which have been described as urging the gripper elements 28 and their associated pistons 27 radially outward, act between the bushings 75a and the bottoms of relatively deep annular grooves formed in the pistons 27. Rings 75h, which are set in grooves formed in the block 75 at the cylinders 26, limit radially outward movement of the pistons 27 and gripper elements 28, so that the gripper elements clear the opening 74 in the block 75.

The block 75 is mounted for angular movement about its opening 74 as an axis, in casing parts 76 and 77, which are fastened together by screws 78. Rings 79 and 80, set in recesses in the block 75, mount the block in the casing part 76 so that an annular space 81 is provided between the block 75 and the casing part 76, through which gas under pressure is supplied from the pump 25 through the valve 24 to the pistons 27 connected with all the gripper elements '28 in all angular positions of the block 75. As shown in FIG. 3, the casing part 76 has a ange extension 82, to which the pump line 24a, exhaust line 29, and valve 24 are attached. Housings 83 and 84 for the solenoids 22 and 23, respectively, are secured to the valve 24. The block 75 has an axial extension 85, to which is secured a 1gear 86 for angularly shifting the block 75.

The purpose in making the block 75 angularly shiftable is to enable the workpiece to be angularly shifted about its own axis between passes through the shaping rolls 10 and 11. It is also contemplated that the workpiece may be shifted axially along the rolls 10 and 11 between passes so that various sections of the rolls axially displaced from one another may operate on the workpiece. For this purpose a structure 87, shown in FIG. 2, is made shiftable into and out of the plane of the paper by means, not shown. The structure 87 is attached by screws 88 to the casing part 77 which helps support the block 75 for the gripper elements 28. The structure 87 is connected in a manner, not shown, to the piston rod 34 so that the gripper elements 28 are enabled to move the workpiece toward and away from the feed rolls 12, 13, 14 and 1.5,Ythe'structure having a groove 89, receiving a rail or land on a bed, not shown, along which the structure 87 moves.

A Mention has been made of the two directions in which the workpiece ino'ves through 'the shaping rolls 10 and 11 and the feedingrolls 12,13, 14,A and 15, and of the. effect:l these directions of movement have in causing the: closing of switch 18 to make the gripper 17 engage orrelease the workpiece. 'Ihe direction of movement of the workpiece is determined by the direction in which the rolls are driven. The shaping rolls and 11, which are geared together for rotation in opposite directions, are driven by a variable-speed reversible motor 90, the speed of` which is determined by a variable resistance 91, and the direction of rotation of which is determined by a reversing switch 92. The speed of each set of feed rolls 12, 13, 14, and 15 is kept a little higher or a little lower than that of the shaping rolls 10 and 11 by a signal generator 93 connected with the motor 90 and a reversing switch 94. If the workpiece is to move to a given set 0f feed rolls from the shaping rolls', then the associated switch 94 is closed so that a reference voltage 94a and the' voltage of the associated signal generator 93 are added to Vone anotheras they are applied to a comparator-95, connected with a power'source 96, in turn connected to a motor 97 for the given set offeed rolls. As a result, the given set of feed rollsV feeds the workpiece faster than the shaping rolls 10 and 11 do, and the workpiece is kept under tension. The other set of feed rolls from which the workpiece is fed intothe shaping rolls 10 and 11, feeds the workpiece more slowly than shaping rolls do, so that workpiece is kept under tension. This is brought about by having the reversing switch 94 associated with the said other set of feed rolls closed so that the voltage of the associated signal generator 93 bucks the reference voltage 94a. The lower rolls 13 and 15 of each set of feed rolls, as is shown for the left-hand set, are driven by the associated motor 97 through a shaft 98 of the motor 97, a gear secured to the shaft 98, gears 100 and 101 meshing with the gear 99, and shafts 102 and 103 connecting the gears 100 and 101 with the lower feed rolls 13 and 15, respectively.

The apparatus of the present invention is ideally suited to the shaping of plutonium articles such as rods or plates, because the indexing gripper 17 is remotely and automatically operated. This gripper, which may be operated Ymanually for conventional metals, can be kept in a special enclosure or container (not shown) to keep air from attacking the plutonium and workers from breathing particles of plutonium. In the special container an inert gas such as argon is used both as an atmosphere filling the container and as the gas under pressure supplied by the pump to operate the gripper elements 28. After a plutonium workpiece to be shaped is inserted in the container, a workmans hands inserted into gloves (not shown) sealed to openings in the container, moves the workpiece into the gripper 17, for example, the one at the left side of the apparatus as viewed in PIG. l. After the workpiece is in the gripper 17, the valve 24 is shifted from the dotted-line position to the full-line position, so that the gripper 17 engages the workpiece. At this time the pistop 33 is at the left end of the cylinder 32 so that the gripper 17 is spaced from the feed rolls 12, 13, 14, and 15.

Now to start a pass of the workpiece through the shaping rolls 10 and 11, various switches are thrown at the same time, perhaps all in a common actuation by virtue of interconnection of the switches. The switch 21 is thrown to energize the solenoid l40 for shifting the valve 36 to the left to admit gas under pressure to the left end of the cylinder 32 against piston 33 and to exhaust gas from the yright end of the cylinder 32, and to make it possible for the solenoid 23 to be energized when the switch 18 is closed. The shaping-roll switch 92 is thrown to make the motor 90 rotate the shaping -rolls 10 and 11 for passage of the workpiece to the right therethrough. The reversing switch 94 for the left-hand set of feed rolls 12, 13, 14, and 15 is thrown to buck the voltage of the signal generator 93 against the reference and rotate the left-hand set of feed rolls for feeding of the workpiece at a slower. speed than the shaping rolls. The reverising switch for the right-hand set of feed rolls is thrown so as to add the voltage of the unshown associated signal generator and rotate the right-hand set of feed rolls for feeding the workpiece at a faster speed than the shaping rolls. The unshown switch corresponding to the switch 21, for the unshown gripper for the right-hand set of feed rolls is thrown oppositely to the switch 21.

When the piston 33 and the gripper 17 move far enough to the right to insert the workpiece between the feed rolls 14 and 15 of the left-hand set, the resultant tipping of the yoke 16 closes the switch 18, energizing the solenoid 23, which moves the valve 24 to the dotted-line position to relieve the vgas pressure against the pistons 27 and to permit the springs 30 -to shift the gripping elements 28 outward away from one another for release of the workpiece. Now the workpiece enters the feed rolls 12 and 13 and continues on to the shaping rolls 10 `and 11, through which it passes and is shaped.

'I'he workpiece continues rightward into the right-hand set of feedV rolls 12, 13, 14, and 15. What happens here with the rightward movement of the workpiece can be understoodfrom imaging that the workpiece is moving leftward through the left-hand set of -rolls 12, 13, 14, and 15. The workpiece first enters the near feed rolls 12 and 13, tilting the yoke 16 counterclockwise; then enters the far feed rolls 14 and 15 moving the yoke 16 back to the horizontal but upward from its original position; and finally leaves the rolls 12 and 13 while still being between the rolls 14 and 15, with the result that the switch 18 is closed. The reversing switch 21 being appropriately thrown, closing of the switch 18 energizes the solenoids 22 and 39 so that the valves 24 and 36 are shifted to cause the gripper 17 to engage the workpiece and the piston 33 Kto move the gripper 17 and workpiece away from the feed rolls 12, 13, 14, and 15. When the piston 33 reaches the end of the cylinder 32, the gripper 17 may be indexed before the passage of the workpiece in the opposite direction through the shaping rolls, either by angular shifting of the block '75 in which the gripper elements 28 are located about the opening 74 in the block as an axis, or by translation of the structure 87, together with the block 75 perpendicularly to the direction of the opening 74 therein. Thus for the next pass through the shaping rolls 10 and 11, the workpiece is angularly shifted about its own axis for thenext shaping operation at the previous region of the rolls, or the workpiece is shifted laterally for the next shaping operation at a region of the shaping rolls displaced axially thereof from the region of the shaping rolls through which the workpiece has just passed.

It is also understood that the invention is not to be limited by the details given herein but that it may be modified within the scope of the appended claims.

What is claimed is:

1. An apparatus comprising a pair of upper and lower shaping rolls, two pairs of upper and lower feeding rolls juxtaposed in operative relation to the shaping rolls, a yoke mounting the two upper feed rolls, a carriage, means pivotally supporting the yoke in the carriage on an axis generally between and somewhat above the upper feed rolls to provide for individual movement of the upper feed rolls away from the lower feed rolls on passage of a workpiece through the feed rolls toward or away from the shaping rolls, a gripper placed on the side of the feed rolls away from the shaping rolls, and electrical means for actuating the gripper, said electrical means including a switch adapted to be closed only by tilting movement of the yoke into a position in which the upper feed roll away from the shaping rolls is farther from its associated lower feed roll than the upper feed roll toward the shaping rolls is from its associated lower feed roll.

2. An apparatuscomprising a Shaper, two pairs of feed rolls juxtaposed in operative relation to the Shaper, a

. 7 yoke mounting a feed roll of each pair, a carriage, means pivotally supporting the yoke in the carriage to provide for selectively increasing the spacing between the feed rolls of one pair and the other pair on passage of a workpiece on its passage through the feed rolls toward or away from Vthe shaper, a gripper placed on the side of the feed rolls away from the shaper, and means for actuating the gripper only in response to tilting movement of the yoke into a position in which the feed rolls of the pair away from the Shaper are spaced apart more than the feed rolls of the pair toward the Shaper.

3. An apparatus comprising a Shaper; two pairs of feed rolls juxtaposed in operative relation to the Shaper; ayoke mounting a feed roll of each pair; a carriage; means pivotally supporting the yoke in the carriage to provide for selectively increasing the spacing between the feed rolls of one pair and the other pair on passage of a workpiece on its passage through the feed rolls toward or away -from the-Shaper; a rotatable `gripper placed on the side of the feed rolls away from the shaper, the gripper comprising a casing, a block rotatably mounted in the casing with an annular space between the interior of the casing and the periphery of the block, the block being formed with six cylindrical radial openings extending outward from a central axial opening, the six radial openings being arranged in three sets of two openings, the openings of each set being 180 apart from one another and having the same location along lthe central opening, the openings of each set being 60 and 120 :from the openings of the other sets and being displaced from the openings of the other sets along the axis of the central opening, gripper elements projecting from the radial openings into the central opening, pistons attached -to the outer ends of the gripper elements and being slidably mounted in the radial openings, springs acting between the pistons and the block to urge the gripper elements radially outwardly, and means for supplying gas under pressure to the said annular space between the casing and the block against the pistons to move the gripper elements radially inwardly; and means for actuating the gripper only in response to tilting movement of the yoke into a position in which the feed rolls of the pair away from the shaper are spaced apart more than the feed rolls of the pair toward the Shaper.

No references cited.

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