US2566240A

US2566240A - Apparatus for piling sheets

Info

Publication number: US2566240A
Application number: US29452A
Authority: US
Inventors: William H Mursch
Original assignee: United States Steel Corp
Current assignee: United States Steel Corp
Priority date: 1948-05-27
Filing date: 1948-05-27
Publication date: 1951-08-28
Anticipated expiration: 1968-08-28

Description

W. H. MURSCH APPARATUS FOR FILING SHEETS Aug. 28, 195] 3 Sheets-Sheet 1 Filed May 27, 1948 Inventor.- W/u/a/w H. M

Aug. 28, 1951 w. H. MURSCH APPARATUS FOR FILING SHEETS Fiied May 27. '1948 3 Sheets-Sheet 2,

I Inventor: lV/LLMM H MUEfiCfZ fill; 4/0/7249.

' Aug. 28, 195] W. H. MURSCH APPARATUS FOR FILING SHEET S Filed May 27, 1948 3 Sheets-Sheet 5 [mental-.-

Patented Aug. 19 51 United States Steel Company, a corporation of New Jersey Application May 21, 1948, Serial No. 29,152

This invention relates to the handling of sheet material and, in particular, to the piling of sheets, such as light-gauge metal sheets or the like, e. g., steel sheets, either tin-plate or tin-mill black plate.

Sheet steel is now largely produced by rolling strip and shearing it to length. If the material is tinned electrolytically in strip form, it is sheared for packing and shipment. Alternatively the uncoated strip is sheared and tinned as sheets by the hot-dip method. In either case, the speed of disposition of the sheared sheets in piles is one of the limiting factors on the speed of continuous strip manufacture. The speed of known sheet pilers is limited by the danger of injury to the sheet edges, particularly in the lighter gauges, by contact with stops and guides. This is caused by the momentum of the sheets resulting from their considerable mass compared to sheets of paper, for example. Bending of the sheet edges, furthermore, is not self -curing as in the case of paper.

I have invented a novel apparatus for piling, particularly adapted for metal sheets and capable of operating at a higher speed than the maxi- 14 Claims. ('01. 271-11) suspension conveyor, closing of the bars to engage a sheet, deceleration of the suspension conmum obtainable by the aid of known pilers, without injury to the sheet edges. In a preferred embodiment, the sheets are discharged successively over a pile support and the tail end of each sheet is seized at the proper time to arrest it positively in vertical alignment with the support. The sheet is then released in mid-air and permitted to fall on the support. Thus the horizontal velocity of the sheet is reduced substantially to zero before it strikes a stop or starts to fall onto the support. V

The apparatus of my invention includes a conveyor, delivery pinch rolls at the discharge end thereof and an electromagnetic suspension conveyor disposed over a pile support and cooperating with the pinch rolls. Clamping bars reciprocable between the pinch rolls and the suspension conveyor are actuated at the proper time to grip the tail end of a sheet as it passes from the pinch rolls to the conveyor and gradually decelerate it before releasing it. The travel of the bars is initiated by'the sheets as they approach a position in vertical alignment with the support. All other operations in a single cycle are controlled automatically in accordance with the advance of the means actuating the clamping bars which is a crank and pitman effective to accelerate, decelerate and reverse the bars until the cycle is completed. These operations include de-ener'gization of the magnets of the veyor and opening of the bars as well as the momentary transfer of a source of compressed air from a pipe with upwardly directed nozzles for floating the sheet to a pipe with downwardly directed nozzles for forcing the tail end of the 'sheet downwardly toward the pile support. A'

pusher actuated by the clamps gently urges the sheets against a fixed end stop as they settle on the pile.

A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accompanying drawings illustrating a present preferred embodiment. v In the drawings,

Figure 1 is a plan view of the apparatus, certain portions being shown diagrammatically;

Figure 2 is a side elevation with parts omitted for clearness;

Figure 3 is a central longitudinal section taken along the line III-III of Figure 1;

Figure 4 is a partial transverse section taken along theline IV'- -IV of Figure 2 with partsin elevation; and

Figures 5 through 8 are diagrams showing the electrical control circuits for various elements of the apparatus.

Referring in detail to to .be piled are delivered by a conveyor ill extending from a shear which serves to cut strip into the desired lengths. The conveyor ill may be of any desired type and is, therefore, illustrated only diagrammatically. The conveyor delivers sheets successively between upper guide plates II, II and a lower guide plate I! into the nip of and lower transverse clamping bars i8 and I9 which are normally spaced apart into cooperating relation to a magnetic suspension conveyor Ill. Air jets from a nozzle pipe 2i extending transversely beneath the clamping bars sustain the leading edge of the sheet until it comes within the field of influence'of electromagnets 20 of the conveyor 20. This conveyor, which is 01 known construction, also includes belts 20 traveling around pulleys 20 mounted on spaced

shafts

22 and 22 journaled in suitable bearings. The shaft 22 is driven from the shaft of one of the drawings, the sheets a maintains energization of theco'il, 32",

switchliisopened." 1 AfterIi-otation of theshaft 30 through a pre- :determined angle, say 70"; cam 40 actuates 0. ':switch 48 which opens the"circuit of arelay l9 1 controlling the energization of themagnets .20 of conveyor 20; Because of the high inductance the pinch .rolls ll through 'a belt-and-pulley any suitable supports. The lower bar i9 is suspended on the piston rods 26 of pneumatic cylinders 21 mounted at each end of the clamp I8. The bars are reciprocated between a position adjacent the pinch rolls i3 and a position adjacent the conveyor 20 by, cranks 28 and pitmans 29. 'if'he cranks are mounted on a shaft 30 journaled above the discharge end of conveyor in in bearings 3|. The-shaft 30 is driven from shaft l6 through a magnetic clutch 32, a pinion 33 and a gear 33. The extension of shaft l6, designated I6", beyond the clutch 32 is provided with an electromagnetic brake 34 which becomes effective when energized to arrest the shaft. A pinion 35 loose on shaft22 meshes with a rack 36 mounted on one end of the clamp I8. The clutch 24 has two windings adapted to be energized alternately. One causes the shaft 22 to be coupled to the shaft 23'. The other causes the pinion 35 to be coupled to the shaft 22.

The operation of the

clutches

24 and 32, brake 24 and cylinders 2.1 is controlled by switches operated by

cams

31, 38, 39 and 40 mounted on the shaft 30. These cams are shown in the idle or starting position, with their switches and the circuits controlled thereby, in Figures 5 through I. The shaft 30 is brought to rest, in a manner to be described later, by the brake 34, with the cranks 28 in the position shown in Figures 2 and 3, i. e., the bars i8 and I! are normally retracted to their position adjacent the pinch rolls. Sheets approaching the piler on the conveyor ill will ordinarily be quite close together. I accordingly drive the pinch rollsat-a speed sufficient to accelcrate each sheet asit is gripped thereby in order to provide separation between sheets.

As a, sheet is delivered from the conveyor l between the guides l'l,"l i and I2, it is seized by the pinch rolls, accelerated and fed between the bars I! and I3 and thence onto the conveyor 20 which advances the leading edge of the sheet over a pile-support (I, -A control device, illustrated as 'aphoto-electr'ic cell 42 and a light source ll, is position'ed'as' shown in Figures'z and 3, to initiate a series-of operations shortly before the leading edgeof the sheet reaches an adjustable endstop .j instead of a photo-electric cell and light source, I'may employ a trip switch or other equivalent control device. Figure shows such a switch at 45. It will be understood, however, that if the photo-electric cell and light source are'em'ployed, they will serve, on interrupof the magnet coils, the flux through their cores does not collapse immediately but only after the lapse of a predetermined time. The magnets, therefore, continue to attract the sheet into contact with the conveyor belts 20 for a short time after operation of relay 49.

When the shaft 30 has turned through about 90, at which time the bars IBand iii are advancing at maximum speed, the cam 38 operates its switch 50. The pinch-roll drive is so arranged that the maximum speed of the clamps will be substantially equal to the speed at which the sheet is fed to the conveyor 20 by the pinch rolls. When switch 50 is operated, it de-energizes the coil 24' of clutch 24 which couples shaft 23 to shaft 22. The operation of the switch also energizes coil 24' of the clutch which couples pinion 35 to shaft 22. At the same time, the switch 50 energizes the operating coil ii of a valve 52. The valve 52 when operated by coil 5i admits air under pressure to the cylinders 21 which immediately causes the lower clamp Is to move upwardly, thereby gripping the sheet between it and clamp 08.

l6 through clutch 32, the bars are decelerated as they approach their extreme position adjacent the conveyor. The sheet and conveyor belts are thus simultaneously decelerated and finally arrested as the leading edge of the sheet engages the endstop 44. When finally released by the conveyor magnets, the sheet starts to fall by gravity onto the pile on support ll between side guides I I. At this instant, i. e., after rotation of shaft 30 through 180, cam 38'cperates switch back to its normal position, as shown in Figure 6. The coil II is deenergized, whereupon, the valve 52 returns to normal position permitting the exhaust of air from the cylinders 21. The lower bar I! re-energized, This re-establishes the connection between the driving shaft 22 for the conveyor if belts and the shaft 23.

tion of the light beam, in the same manner as switch to close the circuit controlled thereby.

Closing of switch 45 energizes a relay 6. Operation of the relay de-energi'zes the .coil .34 of brake 24 and energizes'th'e 0011 -32 of clutch 32.. 1 Ass/result, the-brake 34 is released and shaft I5 Continued rotation of the shaft 30 retracts the bars l8 and. I9. After rotation of the shaft Ill through about 300, cam 39 operates itsswitch 53 to energize a valve coil 54. This coil operates a valve 55 to change the connection of'a source of compressed air from the nozzle pipe 2| to a nozzle pipe 56 disposed above the path of the sheets adjacent the conveyor 20 and having its nozzles directed downwardly. The Jets is coupled to shaft l6. Shaft so is thusfdrive n to turn the cranks 28. and advance the -bars-. I73 and I ll. The cams 31 through I also rotate with the." "shaft 3.. Cam I! first operates aswitch "which opens a had: contact "53in the' circuit of u and; closes a front contact w "which after from pipe 2| are thus cut oil and jets are discharged by pipe 56 to urge the falling sheet downwardly so that its trailing edge-will clear' the leading edge of the next succeeding sheet. The fall of .the sheet permits re-establishment of the beam from the source 43 to the photo-electric cell 42 or opening of switch is. This de-. energizes relay 45 but the operation of. itscdntact does not have any immediate eflect. When the shaft 30 has turned through about 350. how-j ever, it operates switch 41, cle-energizing clutch coil 32* and re-energizing brake coil 34'. .01)- eration of the brake arrests the shaft .3lisub stantially in the zero or starting position in which it is shown in Figures 2 and 3. As the shaft is arrested, cam ll operates its switch II to transfer the connection from the source of compressed air from nozzle pipe I back to pipe All the parts of the apparatus are thus restored to their original positions so that they are ready for the start of the next cycle of operations when the leading edge of the succeeding sheet reaches the position where it interrupts the beam from the source ll to the photo-electric cell .2 or closes switch ll.

Since the sheets are arrested in accurately determined position over the pile support. they should fall on the latter with their edges in alignment. In order to insure exact alignment of the leading and trailing edges, however. I emplay pusher finger 51 extending upwardly from a shaft ll journaled in suitable bearings. The shaft is rotated clockwise through a slight angle by an engagement of the bar I! with a finger 59 at one end of the shaft and is returned by a spring II when the clamp is retracted.

It will be apparent that the invention is characteriaed by numerous advantages over sheet pilers as known heretofore. In the first place, the piler of my invention may be operated at a higher speed than pilers which rely on fixed stops to arrest the sheets and avoids the possibility of injury resulting from the momentum of the sheets. The arrest of the sheets in a position above the pile support is effected by eizure of the tail and through the medium of traveling clamping bars which decelerate gradually to rest. The sheet is held above the pile support by the conveyor until it is in proper position to fall accurately on the pile. The bars engage the sheet when traveling at the same speed as the latter and the conveyor is decelerated along with the bars, thus avoiding any buckling of the sheets.

The controls for the variou elements are simple cam switches which can readily be changed for accurate timing in order to insure that the desired sequence of operations will occur in proper order. The sequence, furthermore, is automatically controlled when once initiated by the arrival of a sheet at the proper position for deceleration. Up to that time, the sheet travels at maximum speed. The crankshaft actuating the clamping bars is automatically stopped at the correct position for. the start of the succeeding cycle. The upwardly directed air Jets sustain the leading edge of the sheet until it is within the eil'ective range of the conveyor magnets and the downwardly directed jets blow each sheet out of the way of the next succeeding sheet.

Although I have-illustrated and described only a preferred embodiment and practice of the invention, it will be recognized that changes may be made in the construction and procedure disclosed herein without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. Apparatus for piling sheets comprising means for discharging sheets toward a pile support, an electromagnetic suspension conveyor above said support adapted to receive sheets from said means, clamping bars reciprocable between said first-mentioned means and said support, and means establishing a temporary driving connection between said bars and said conveyor as a sheet approaches a position overlying said support.

2. The apparatus defined by claim 1 characaseaaso port, a drive for said conveyor and means effective to disconnect the conveyor from said drive and establish a temporary driving connection between said bars and said conveyor as a sheet approaches a position overlying said supp r I '4. The apparatus defined by claim 3 characterized by a member driven by movement of the bars, said last-mentioned means including a clutch selectively engageable with said drive or said member.

5. Apparatus for piling sheets comprising a pair of pinch rolls adapted to discharge sheets successively onto a pile support, a pair of cooperating clamping bars reciprocable sidewise between a position adjacent the rolls and a position adjacent the support, means set in operation by the arrival of the leading edge of a sheet from the pinch rolls at a predetermined point over said support for reciprocating the bars from the first-named position to the second and back, and pneumatic cylinders on one of said bars effective to cause them to close on a sheet passing therebetween.

6. Apparatus for piling sheets comprising a pair of pinch rolls adapted to discharge sheets successively onto a pile support, a pair of cooperating clamping bars extending transversely of the path of the sheets and reciprocable between a position adjacent the rolls and a position adjacent the support, means set in operation by the arrival of the leading edge of a sheet from the pinch rolls at a predetermined point over said support for reciprocating the bars from the first-named position to the second and back, and means for causing said bars to grip a sheet passing therebetween at a pre- .determined point in its travel.

terized by said first-mentioned means including a crank and pitman actuating said bars and an electromagnetic clutch effective to connect said crank to a power source.

8. Apparatus for piling sheets comprising means for discharging sheets toward a pile support, a pair of sheetgrlpping bars extending across the path of the sheets and movable back and forth between said means and said support, means for reciprocating the bars toward and from said support and means for actuating the bars to grip a sheet passing therebetween as they approach the support.

9. The apparatus defined by claim 8 characterized by said reciprocating means including a crank and pitman and control means therefor actuated by the leading edge of the sheet.

10. Apparatus for piling sheets comprising means for discharging sheets toward a pile support, an electromagnetic suspension conveyor above said support adapted to receive sheets from said means, two nozzle pipes between said firstmentioned means and said conveyor, one pipe below the path of the sheet discharging upward jets and the other above said path discharging 7. The apparatus defined by claim 6 characdownward jets, a change-over valve for transferring an air supply from the first pipe to the second and means for operating said valve as a sheet approaches a position over said support.

. 11. Apparatus for piling sheets comprising means for discharging sheets toward a pile support, transverse sheet-gripping barsreciprocable' sidewise between said means and said support in the direction of the travel of the sheets, means for reciprocating the bars sidewise from said means toward said support and back and means for actuating the bars to grip a sheet passing therebetween as they approach the support, said last-mentioned means including control means driven by said second-mentioned means.

12. Apparatus for piling sheets comprising means for-discharging sheets toward a pile support, transverse sheet-gripping bars reciprocable sidewise between said means and said support in the direction of travel of the sheets, means, for reciprocating the bars sidewise from said means toward said support and back and means for actuating the bars to grip a sheet passing there- 2 between as they approach the support, said firstmentioned means being a pair of pinch rolls, a

shaft for driving said pinch rolls, a clutchfor connecting said second-mentioned means to said shaft, and means actuated by the sheets delivered by the pinch mils for controlling said clutch. I

13. Apparatus for pilingsheets comprising a pair of pinch rolls adapted to discharge sheets successively onto a pile support, a pair of cooperating clamping bars parallel to said rolls reciprocable between a position adjacent said rolls and a position adjacent said support. means for reciprocating said bars between said positions REFERENCES orrEn Thefollowing references are of record in the file of this patent:

' UNITED STATES PATENTS Number Name Date 1,378,886 Maineri May 24, 1921 1,444,999 Bennett et a1 Feb. 13, 1923 1,537,594 Elsworth et a1 May 12, 1925. 1,663,815 Rich et al May 27, 1928 1,736,482 Broadmeyer Nov. 19, 1929 1,873,316 Droitcour Aug. 23, 1932 1,892,590 Steele et a1. Dec. 27, 1932 2,130,841 Eckhard Sept. 20, 1938 2,183,798 Theiss Dec. 19, 1939 2,208,978 Harrold et a1 July 23, 1940 2,332,863 Luehrs Oct. 26, 1943 Buccicone Apr. 24, 1945