US2355079A

US2355079A - Sheet slitting machine

Info

Publication number: US2355079A
Application number: US432353A
Authority: US
Inventors: Lyman L Jones
Original assignee: American Can Co
Current assignee: Primerica Inc
Priority date: 1942-02-25
Filing date: 1942-02-25
Publication date: 1944-08-08
Anticipated expiration: 1961-08-08

Description

Aug. 8, 1944. L. l.. JONES 2,355,079

SHEET SLITTING MACHINE Filed Feb. 25,-'1942 4 Sheets-Sheet l A T TOENEYS Aug. 8, 1944. 1 L. JONES I `SHEET SLITTING MACHINE 4 sheets-sheet 2 Filed Feb. 25, 1942 Aug. 8, 1944.

L. l JONES SHEET SLITTING MACHINE Filed Feb. 25, 1942 4 Sheets-Sheet 3 f INV ENT OR. ,.f. r I

vATTORNEYS Aug. 8, 1944. L. l.. JONES* SHEET SLITTING MACHINE 4 sheets-sheet 4 Filed Feb. 25, 1942 IyNTOR.

A TTONEYS Patented Aug. 8, 1944 UNITED STATES PAT ENT oFFlcE SHEET SLITTING MACHINE Lyman L. Jones, Seattle, Wash., assignor to Amer.. 'A loan Can Company, New York, N. Y., a corporation of New Jersey Application February 25, 1942, Serial No. 432,353

9 claims.

or the like, are trimmed and cut into blanks from f I which can bodies are formed. These sheets as they come from the plate mill are of such a dimension that a predetermined number of body blanks of a given size may be cuil from each sheet. The sheets are often out-of-square and lhence one or more of the blanks when cut from such a sheet may be under size to such an extent that they cannot be used. If such defective blanks are not segregated from the good .or full size blanks they cause trouble in subsequent operation machines that prepare and form the blanks into can bodies.

The'instant invention contemplates overcoming this difiiculty by providing devices which gauge the sheets prior to their being cut and whichy detect out-of-square sheets and discard them from the machine. An object therefore of the invention is the provision in a sheet slitting machine of devices wherein sheets passing through the machine are gauged for out-of-squareness prior to being cut and if found defective, are discarded from the machine so that they may be used for other purposes. L

Another object is the provision of such a machine wherein the steps of detecting and discarding defective sheets are effected by electrically operated elements so that the operation is entirely automatic and accurate, thereby eliminating the human judgment factor of inspec- Y tion.

Another object is the provision of a tandem machine wherein the sheets'are gauged and electrically detected prior to their being cut lengthwise and again prior to their being cut transversely of the sheet so that a nished blank will be true to size and square on all edges. l

Numerous other objects and advantages ofthe invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

Figure 1 is a top plan view of a sheet slitting machine embodying the instant invention, with parts broken away, the view also showing a plurality of sheetsand blanks passing through the machine; l

Fig. 2 is a wiring diagram of the electric apparatus used in the machine;

Fig. 3 is a longitudinal section taken substantially along the line 3 1 in Fig. l, with parts broken away;

Fig. 4 is an enlarged side elevation of one of the mqvablegauging devices used in the machine, the view being taken substantially alongv a plane indicated by the line I-l in Fig'. 1, with parts broken away;

Fig.- 5 is a top plan view of the device illustrated in Fig. 4, with parts broken away;

Fig. 6 is a view similar to Fig. 4 and illustrating one of the ilxed gauging devices used in the machine, the view being taken substantially along a plane indicated 'by theline 8 8 4in Fig. 1, with parts broken'away;

Fig. 7 is an enlarged sectional detail taken substantially alongv the line 1-1 in Fig. l, with parts broken away; n

Fig. 8 is a transverse section taken substantially along the line 8-8 in Fig. l, with parts broken away;

Figs. 9 and 10 are enlarged sectional detailsv taken substantially along the line 9 9 in Fig. l,

with parts broken away, the views showing certain of the movable parts of the machine and a blank passing through the machine in diierent positions; and

Fig. 11 is a schematic perspectiveviewshowin g how the various rotating parts of the machine are driven.

As .a preferred embodiment of the invention the drawings illustrate Aprinci-pal parts of a tandem slitting machine of the character disclosed in United States Patent 1,841,426, issued Jannary 19, 1932, to J. C. Balletti, on Body blank sorting apparatus for plate slitting machines. In such amachine metal sheets A (Fig. 1) are conveyed longitudinally of the machine and are trimmed and cut into two smaller size sheets B. These sheets B are thenconveyed transversely of the machine at right angles to their ilrst path of travel, and are again trimmed and cut into -can body blanks C. This completes the slitting operations and accordingly the blanks are conveyed to a suitable place of deposit.

The sheets A enter the machine from any suitable source of supply of such sheets, pass along an inclined runway which includes a plurality.

of rails Il (Figs. 1 and 3). These rails are secured to a table l2 which forms a continuation of the rails. The table is formed on an adjust-4 able sub-frame I3 mounted onya transverse pivot pin I4 carried in a base I5. The outer ends of the rails are braced by a connecting bracket I6 and by a pair ofangle irons I1 which extend from the bracket to the base.

The sheets A are propelled along the runway by an endless chain conveyor I8 (see also Fig. 11) having feed Vdogs I9 secured thereto `at spaced intervals. The chain operates,r over a driving sprocket 2I and overa plurality of idler spreek-- ets 22. The idler sprockets 22 are mounted on cross shafts 23 journaled in bearings formed in the sub-frame.i3 and in a guard bracket 24 secured to the rail connecting brackets I6.

The driving sprocket 2| is mounted on a drive shaft 26 which is journaled in bearings 21 formed in the machine base I5. This drive shaft constitutes the main driving shaft of the machine and is rotated in any suitable manner.

As the conveyor I8 is thus driven by the drive sprocket'2 I, thedogs I9 on the chain engage behind the sheets A placed on the runway and propel them forwardly along the runway rails II. 'Ihe sheets are guided along a straight line path of travel by a pair of spaced and parallel guide rails 29 which are formed on4 the outer runway rails II.

The conveyor I8 -propels the sheets A toward a plurality ofcooperating upper and lower trimming and slittingrotary cutters 32 which are located adjacent the inner edge of the'table I2 so that the sheets to be cut will pass between them. These cutters are mounted on a pair of spaced and parallel horizontal shafts 33, 34 (see also Fig. 11) which are journaled in bearings 35 formed in thesub-frame I3. The shafts extend beyond the bearings on one side of the subframe and carry meshing gears 36, 31 so that 4 the cutters will rotate in unison.

The lower cutter shaft 34 is rotated by a sprocket 38 which is mounted on the shaft adjacent the gear 31. This sprocket is driven by an endless driving chain 39 which operates over a sprocket 4I on the main driving shaft 26. The chain also operates over and drivesa sprocket 42 (see also Fig. '1) which is mounted on a cam shaft 43 journaled in bearings 44 formed in the sub-frame I3. This is a usual slitter construction. f

When a moving sheet A propelled by theicon'- veyor I8 is fully on the table I2 it is gauged for squareness just before it passes between the cutters 32. 'Ihis gauging is brought about by a pair of fixed gauges 52 which are disposed along one side of the machine as viewed in Fig. 1 and by a flexible gauge 53 which is located along theoppostie side of the machine. The fixed gauges 52 (see also Fig. 6) depend from brackets 55 which are secured to a gauge bar 56 fomed on a gauge slide 51 located in a slideway 58 of a slide bracket 59 bolted to the sub-frame I3.

. The gauge slide 51 carries an actuating pin 62 which extends down through the bottom of the slide bracket 59.

shaft 43 and the cam 65 carried thereon, the latter at the proper time shifts the. slide 51 and its gauge bar 56 inwardly toward the moving sheet A as it passes across the table I2.- `'I'his movement of the gauge bar brings the vertically The lower end of this pinA operates in a cem groove 64 of a barrel cam 65.505

disposed iixed gauges 52 into position closely 75 adjacent the longitudinal edge of the moving sheet A. y At tne same time the iiexible gauge 53 is shifted toward the opposite edge of the moving sheet. This exible gauge includes a vertical roller 68 (see also Figs. 4 and 5) which is carried on the outer end of a gauge arm 61 mounted on a pivot pin 68 secured in a gauge block 69 bolted to a gauge bar 1I. A- compression spring 12 interposed between the gauge arm 61 and the gauge block 69 maintains the arm extended in the dlrection of the passing sheet A. 'Ihe arm adjacent the pivot pin 68 is formed with a stop lug \13 which strikes against the gauge block 69 and thus limits the outward travel of the arm.

The gauge bar 1I on which the flexible gauge unit 53 is mounted, is formed integrally with a horizontal gauge slide 16 (see also Fig. 7)' which moves in a slideway 11 of a slide bracket 18 bolted to the sub-frame I3. The slide carries a depending actuating pin 19 which extends down through a slot 8l in the bracket.' The lower end of this pin operates in a cam groove 82 of a barrel cam 83 mounted adjacent the sprocket 42 on the cam shaft 43. This cam and slide construction is identical with the opposite cam 65 and slide 511 and they are actuated simultaneously by he rotation of the cam shaft 43.

Hence the rotating cam 83 shifts its gauge slide 16 and the gauge bar 1I inwardly toward the sheet A simultaneously with the movement of the opposite gauge bar 56. During this movement the roller 66 of the flexible gauge unit 53 engages against the adjacent edge of the passing sheet A and shifts the sheet transversely of the table I2 and into engagement with the two iixed gauges 52. 4Thus, there is brought about a momentary three point contact with the sheet which aligns thelongitudinal edge at the right of the sheet as .viewed in Fig. 1, withl the two xed gauges 52.

If the sheet is square, as it should be, the longitudinal edge at the left of the sheet as viewed in Fig. 1 will be parallel with the opposite edge. If it is out of square this edge at the left of the sheet will be out of parallel with the opposite edge and lwhen the sheet is out of square beyond certain limits, which cannot be compensated for by trimmingthe sheet, it is a defective sheet and is discarded from the machine.'

Detection of a defective sheet is brought about by a pair of spaced detecting elements 86 (Fig. 1) which are located on the gaugebar 1I, one

on each side o f the iiexible gauge unit 58. Each of these detecting elements 86 includes a roller 81 which is disposed adjacent the edge of the passing sheet A and which is carried on one leg of a bell crank lever 88. The bell crank levers are mounted on pivot pins 89 'which are carried in the gauge bar 1I. 'I'he otherleg of each of the bell crank levers engages against the movable element of a. pair of normally open electric switches l.9| which are secured to the gaugeV 2,855,079 above the path of travel of the sheets B as they' come from the cutters 32. In this position of the fingers the good sheets, i. e., those which are in square, pass under the ingers for a subsequent cutting operation. When ran out-of-square sheet A is detected, the gate fingers 96 are lowered to a position below the path of travel of the good sheets and this deects the. sheets B as they leave the cutters and directs them into the discard bin 91.

This operation of the gate fingers 96 is brought about by the combined`vaction of both of the detector switches 9| on the gate solenoid 92. When a sheet A is square, both detector elements 86 will engage the sheet edge simultaneously' and thus will close both of the detector switches 9|. When both switches are closed the gate solenoid is energized to shift the gate fingers into their normal position. y

When a' sheet A is out-of-square, the edge of the sheet adjacent the detector elements 86 will be inclined or tapered and hence only one of the elements` will engage the sheet. Thus only one of the detector switches 9| will be closed. This condition will de-energize the gate solenoid 92 and thus shift the gate ngers 96 into a sheet defiecting position as mentioned above. This energizing and deenergizing of the gate solenoid is brought about bya plurality of electric circuits which will now bel explained.

When both of the detector switches 9| are closed, by the detection of a square sheet A, electric energy from the generator |04 flows along the circuit just explained and energizes the solenoid relay |06. Energizing of this relay shifts its movable core |01 and thus closes two normally open switches l2 which are connected to the core. Switch is part of a holding circuit which includes a cam operated normally closed switch H3.

Since the greater number of sheets which pass through the machine are good sheets, vthe holding circuit is incorporated in the apparatus to hold the gate ngers 96 in their normal position to prevent shifting of the gate fingers for each sheet. For this purpose one side of the cam switch H3 is connected by a wire I4 to the lead wire |02. The other sideof the cam switch is connected by a wire |5 to the switch l This switch is also connected by a wire |6 to .the wire |05.

The cam switch |3is mounted on a side of the subframe |3 adjacent the gauge slide cam 03 (Fig. 7) and is, actuated by a cam projection |19 formed on the slide cam. This cam projection ||9 momentarily opens the cam switch ||3 Just prior to the closing of the detector switches 9|. The cam switch ||3 closes again before the detector switches open and thus electric energy passing along this holding circuit holds the solenoid relay |06 energized.

` rail |33 anda straight stop rail |34.

f Way rails The switch ||2 forms a part of a gate solenoid circuit which includesvthe gate solenoid 92. One side of the switch isf'connected by a wire |2| to the lead wire |02. The opposite side of the switch is connected by;` a' wire |22 to the gate solenoid 92.

The solenoid is also connected by a wire |23 to the return wire |08. i

Hence when the switch ||2 is closed by the energizing of the relay |06, electric energy from the generator |04 passes along this solenoid circuit and energizes the gate solenoid 92. It is this energy that maintains the solenoid 92 energized and thus maintains the gate fingers 96 in their normal position as long as good sheets A are passing through the machine.

When an out-of-square sheet is encountered and one of the detector switches 9| remains open when the cam switch ||3 opens,.all circuits are immediately broken and the gate solenoid 92 is de-energized. It is this action that shifts the gate fingers 96 into sheet deflecting position, as hereinbefore explained.

The good or in-square sheets B as they come from the cutters 32 fall upon an auxiliary or transverse conveyor |3| (Figs. 1, 3, 8 and 1l) having spaced feed dogs |32 which propel the sheets B transversely through the machine, at

` right angles to their former path of travel. Such latter travel is for a blank cutting operation, as

The drive shaft |5| is driven by a sprocket |54 which is mounted on the shaft and which is rotated by an endless driving chain |55. The

I mounted on the lower of a pair of spaced, parallel cutter shafts |61, |66 vlocated adjacent the inner end of the table |36. These 'shafts are journaled in bearings |69 formed in the sub-frame I4| and are rotated in unison bysmeshing spur gears |1| mounted on the outer ends of theA shafts. The shafts carry a plurality of spaced cooperating cutter wheels |12 between which the sheets B are These guide |88 cooperate with a pair of xed gauge elements ner of operation are identicalto the cutters 32. 5

|9| (seealso Figs. 9 andlO) located adjacent the cutter wheels |12. These gauge the sheets B with a four point contact.

The gauge elements |9| are held underA spring tension by spring |96 (Fig. 10) having one end secured to one of the bearingblocks |95 and having its opposite end hooked into a lever arm |91 40 which is carried on the cross shaft l|94.. These gauge elements extend downwardly around the rear of the upper cutter shaft '|68 and their lower c ends project inwardly of the cutter wheels and terminate in the path of travel of the sheets B 5 moving toward the cutters. These lower ends of the elements are formed with gauge surfaces |98.

Hence as a sheet B moves along the table |96 toward the cutter wheels |12, its leading edge iirst'engages 'the' gauge surfaces |98 of the two 50- gauge' elements |9I. It will be remembered that this leading edge has been cut square by the cutters 32- as the sheet passed longitudinally through the machine and thus this edge is used to bring the sheet into square Justprior to its being cut transversely by the cutter wheels |12. A The sheet B being propelled by the conveyor dogs |32 is pushed against the gauge elements |8|, against the resistance of the tension spring |96` and this resistance permits the sheet to turn 50 slightly as it moves forwardly until both gauge elements are engaged by the sheet edge. When both elements are engagedthe sheet edge .is parallel with the cutter shafts |61, |68 and-ls there-4 fore in square. 05

Simultaneously with this squaring of the sheet B, the side gauge bars |84, move 'in toward .he sheet. During this movement of the gauge .bars the exible gauge element |88 engages the sheet along the adjacent side edge and pushes the 7o 'sheet across the table into engagement with the' fixed gauge |86 onthe opposite gauge bar |86. 'I'hus thesheet is located by a four-point contact -which prepares the sheet for cutting.

While a sheet'B is thus being` located for cut- 75 ting into blanks C, its side edges which thus far have not been trimmed, are detected for out-ofsquareness with the front and rear edges. This detecting is effected by four detector elements 20| which are identical to the detector elements 86 hereinbefore mentioned. These elements like the elements 86, include rollers mounted on lever arms which actuate normally open electric switches 202 carried on the gauge bars |84, |85. 'Ihere are two of these switches on each gauge bar and they are located one on each side of the gauge elements |86, |88.

Thedetector elements 20| engage against the side edges ofl the sheet being gauged and close the switch when these edges are square with the front and rear edges of the sheet. If one or both of the sheet side edges are tapered or inclined out-of-squar'e beyond a predetermined limit, one or more of the switches will not be closed and hence the sheet will be detected as an out-ofsquare sheet and will be discarded.

Discarding of an out-of-square sheet is brought A about by a gate 205 (Fig. 8) which extends across the machine just beyond the cutter wheels |12. 'I'his gate is ilxed on a shaft 206 which is mounted in I bearings in the sub-frame |4|. I'he shaft l carries a lever arm 201v (Figs. 9 and 10) which is connected to a movable core 208 of an elect'ric solenoid 209 which is actuated by the def tector switches 202 through suitable electric circuits, which will be hereinafter explained.

The normal position of the gate 205 is shown in Figs. 8 and 9. Square sheets after being cut into blanks C pass over the top of the gate and are directed onto a continuously moving conveyor y belt-2| which carries them to a suitable place A of deposit. The belt operates .over a pulley,2|2

mounted on a shaft. 2|8 carried in bearings 2|4 formed in a stand 2|5 located adjacent the discharge end ofthe machine. A stop plate 2I6 secured to the stand adjacent the far side of the l belt locates the blanks C on the beltas they pass from the cutter wheels |12.

If an out-of-square sheet B is detected, the de-4 tector switches 202, operatethe solenoid 209 to rock the gate 206 into the position shown in Fig. 10. In this position of the gate, blanks CV 4as they come from lthe cutter |12,A are deected downwardlyvas shown in Fig.l 10 and'are deposited into a bin 2I8 located in the bottom of the stand 2 I 5.

Reference now should be made to the portion of the wiring diagram at the right of Fig. 2. In this portion of the diagram the four detecting switches 202 are connected in series by wires 22|. 'I'he flrst of the switches is connected by a wire 222 to the main lead wire |03 which leads from the generator |04. The last of the switches is connected by a w'ire 223 to asolenoid relay 224 having a movable corev 225. 'I'he relay is also connected by a vwire 226 to the main return wire |09 which connects with the generator.

'When all four detector switches 202 are closed.'

by the detection of a square sheet B, electric energy flows from the generator |04 along this circuit and energizes the solenoid relay 224. En# ergizing of this relay shifts its movable core 225 .and this closes two normallyopen switches 228,

229 which are connected to the core. Switch 228 is part of a holding circuit which includes a cam operated normally closed.switch23|. g

Since the greater number of sheets Bwhich pass through the machine are good sheets, the

holding circuit is. incorporated 1n the apparatus' te hold the gate 286 in. its normal positicn to preventshifting of thel gate for each sheet. For this purpose one side of the cam switch 23| is connected by a wire 232 to the lead wire 222. The other side of the cam switch is connected by a wire 233 to the switch 228. Switch 228i is also connected by a wire 234 to the wire 223.

The cam switch 23| is mounted on a side of f the sub-frame |4| adjacent the gauge slide cam |16 and is actuated by 'a cam projection on the cam |116 in the same manner as the cam projection ||8 on the cam 83, as shown in Fig. '1. This cam projection momentarily opens the cam switch 23| just prior to the' closing of the detector switches 202. The cam switch closes again before the detector switches open and thus. electric energy passing along this holding circuit maintains the solenoid relay 224 in an Aenergized condition.

The switch 229 on the relay core 225 forms a part of a gate solenoid circuit which includes the gate solenoid 209. One side of the switch is connected-by `a wire 235 to the lead wire 222. The

opposite. side of the switch is connected by a wire' 236 to the gate solenoid 209. The solenoid is also connected by a wire 231 to the return lead wire 226.

Hence when the switch 229 is closed by the energizing of the relay 22d, electric energy from the generator |04 passes along this solenoid circuit and energizes the gate solenoid 209. It is this energy that maintains the solenoid 209 energized most of the time and thus maintains the gate 205 in its normal position as long as good sheets B are passing through the machine.

When an out-of-square sheet is detected and one or more of the detector switches 202 remain open when the cam switch 23| opens, all of the normal circuits are immediately broken and the gate solenoid 209 is de-energized. It is this action that shifts the gate 205 into sheet deecting position (Fig. 10) as hereinbefore explained. It is thought that the invention and many of its attendant advantages will be understood fromthe foregoing description, and it will be apy parent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. vIn a sheet slitting machine, the combination of a conveyor for propelling sheets to be cut through the machine, gauging devices disposed adjacent the path of travel of the moving sheets for bringing the sheets into a predetermined position, detecting elements located adjacent said gauging devices and engageable with an edge of asheet for detecting such an out-of-square condition that squared sheets of proper size cannot be cut from said sheet, and means operable by said detecting elements for discarding the outof -square sheets from the machine.

2. In a sheet slitting machine, the combination of a conveyor for propelling sheets to be cut through `the machine, gauging devices disposed adjacent the pathfof travel of the moving.

predeteran out-of-square sheet is detected, an electric. solenoid connecting with and operable by said.

switches, and a gate located in' the path of travel of said sheets and operable by said solenoid to dellect out-of-square sheets from the machine.

3. In a sheet slitting machine, the combination of a conveyor for propelling sheets to be cut along a path of travel in one direction, an auxiliary conveyor for receiving cut sheets from the rst conveyor and for propelling them in another direction, gauging devices disposed adjacent both paths of travel of the sheetsv for bringing the sheets into predetermined positions, detecting elements located adjacent said gauging devices for' detecting suchA out-of-square sheets that squared sheets of proper size cannot be cut from said sheet, and means adjacent the discharge end of each conveyor and operable by the detecting elements of its conveyorfor discarding from the machine out-of-square sheets detected on that conveyor. Y

4. In a sheet slitting machine, the combination of a plurality of conveyors disposed at angles to each other for propelling sheets to be cut along paths of travel extending in vdiierent directions, cutter wheels located adjacent each conveyor for trimming and cutting the sheets into a plurality of rectangular blanks, movable gate members adjacent each set of cutter wheels for guiding sheets from one conveyor to the next in line, gauging devices disposed adjacent each set of cutter wheels for bringing the moving sheets into a predetermined position prior to cutting, detecting elements located adjacent said gauging devices for detecting such out-of-square sheets that operation edge trimming unit havingka longitudi-A nal sheet guiding feedway thereon, a second operation edge trimming unit having a longitudinal sheet guiding feedway thereon disposed in a'right angular relation to the first mentioned feedway and in position to receive partially trimmed sheets therefrom, sheet edge trimming equipment .on the first operation unit, sheet edge trimming equipment on the second operation unit, means for feeding sheets over the ilrst operation unit feedway and onto the other feedway, means for feeding sheets over the second operation feedway, a set of laterally reciprocable `gages engageable with the sheets while moving to the rst operation trimming equipment, a set of laterally reciprocable gages engageable with the sheets while moving to the second operation trimming equipment, the first operation gage set including two longitudinally spaced gage elements engageable with sheet edges at one side of the associated feedway and a single gage element engageable with sheet edges at the Iether side of said associated feedway inte-rmediately of said two gage' ele"- ments, and means for reciprocating said gage sets, and detecting means associated with said first and second operation umts for detecting such out-of-square sheets that sheets of proper size cannot be produced therefrom by said units.

6. A sheet edge trimming machine structure as defined in claim 5 in which the single gage element which intermediately opposes the two longitudinally spaced gage elements is yieldably mounted so as to -be displaceable by such out-of-square sheet. f f

7. In a sheet edge trimming machine, a rst operation edge trimming unit having a longitudinal sheet guiding feedwaythereon, a second operation edge trimming unit having a longitudinal l `sheet guiding feedway thereondisposed in a right 4angular relation to the rst mentionedfeedway gf; and in position to receive partially trimmed sheets y therefrom, sheet edge trimming equipment on the iirst operation unit, sheet edge trimming equipment on the second operation unit, means for feeding sheets over the rst operation unit feedway and onto the other feedway, means for feeding sheets over the second operation feedway, a

set of laterally reciprocable gages engageable.

with the sheets while moving to the first, operation trimming equipment, a set oflaterally reciprocable gages engageable with the sheets while moving to the second operation trimming equipment, said last mentioned feeding means including four feeding and rectifying elements yieldably engaging a sheet at four points in two pairs one pair engaging in laterally spaced relation at the advance previously trimmed edge of the sheet and the other pair engaging in laterally spaced relation adjacent the untrimmed edges of the sheet, and detecting means associated with said first and second operation units for detecting such out-of-square sheets that sheets of proper size cannot be produced therefrom by said units.

means for feeding sheets to said trimming equipment, a set of laterally reeiprocabie gages engageable with the sheets while moving to the trimming equipment and including two longitudinally spaced gage elements engageable with sheet .edges at one side of the feedway and a single gage element engageable with sheet edges at the other side of the feedway intermediately of said two gage elements, means for reciprocating the gage elements into and out ot contact with sheet edges, detecting means positioned adjacent said feedway for detecting such out-of-square sheets that sheets ofproper size cannot be produced therefrom. by said units, and means operable by said detecting means for discarding the out-of-square sheets from the machine.

9. A sheet edge trimming machine structure as defined in claim 8 inwhich the singl gage element which intermediately opposes the two 1ongitudinally spaced gage elements is yieldably mounted so as to be displaceable =by such out-oi!- square sheet.

L'YMAN L. JONES.