US2677543A

US2677543A - Sheet feeding mechanism

Info

Publication number: US2677543A
Application number: US166907A
Authority: US
Inventors: Rudolph E Ohrn
Original assignee: Container Corp
Current assignee: Container Corp
Priority date: 1950-06-08
Filing date: 1950-06-08
Publication date: 1954-05-04
Anticipated expiration: 1971-05-04

Description

May 4, 1954 R. E. OHRN SHEET FEEDING MECHANISM 4 Sheets-Sheet 1 Filed June 8, 1950 fnveni or' J fucZo 05.772,

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mm Nan L May 4, 1954 4 Sheets-Sheet 2 Filed June 8, 1950 llllL Wiiflifl .l.|.L

May 4, 1954 R. E. OHRN SHEET FEEDING MECHANISM 4 Sheets-Sheet 3 Filed June 8, 1950 y 4, 1954 R. E. OHRN SHEET FEEDING MECHANISM 4 Sheets-Sheet 4 Filed June 8, 1950 fnz/enr" .EZLdODAE Gkrn Patented May 4, 1954 UNITED STATES PATENT OFFICE SHEET FEEDING MECHANISM Rudolph E. Ohrn, Rock Island, 111., assignor to Container Corporation of America, Chicago, 111., a corporation of Delaware Application June 8, 1950, Serial No. 166,907

2 Claims. 1

The present invention relates to sheet or blank feeding mechanism, and more particularly to a sheet feeder for relatively thick sheets of paperboard or the like which can be engaged by an edge and fed to a sheet treating device. More specifically, the invention relates to supplemental feeding mechanism which initiates feeding of a sheet or blank from the bottom of a stack to facilitate engagement thereof by the primary or main feeding means.

Briefly, the disclosed embodiment of the invention comprises supplemental feeding mechanism which is combined with the feeding means of a sheet treating device or machine, in this instance a folding and stapling machine for corrugated or other types of paperboard container blanks. The main feeding means are shown as of the reciprocable type having an engaging element which in forward movement engages the rear edge of a blank to move the blank forwardly, and in its rearward movement rides under the stack of blanks to a position just rearward of the next blank for engagement therewith upon the next forward movement. The supplemental feeding means comprises a plurality of feeder elements or dogs extending radially from a rock shaft disposed below the stack. The upper surface of each dog is stepped to provide a forward portion which is adapted to support the stack and a rear portion positioned behind the stack, with an abutment or engaging portion between the forward and rear surface portions adapted to engage the rear edge of the lowermost blank of the stack upon forward swinging of the dog. Since the abutment moves in an arcuate path, the rear portion of the forwardly moving blank is swung downwardly from the stack and at the same time the rear surface portion engages under the next higher blank and raises the stack slightly. The lowermost blank is'thus positively separated from the stack and moved forward to a position corresponding to the rearmost position of the engaging element of the main feeding means so as to be engaged and moved forwardly thereby. Positive feeding of a single sheet or blank in each feeding cycle is assured by this construction.

Rocking of the feed elements or dogs is preferably so timed that they reach their forward limit of movement as the engaging member of the main feed means reaches its rearward limit, so that feeding of the blank is taken over by the main feed means as the supplemental feeder dogs begin their return movement. In the present instance, the main feed means is reciprocated by a walking beam and the desired timed relation is effected by a simple lever linkage between the rock shaft and walking beam. It will be evident that the disclosed construction has many advantages over conventional sheet feeding mechanisms. For one thing, by separating the lowermost blank from the stack, it prevents more than one blank being engaged by the main feeding means. Again, the supplemental feed elements engage the rear edge of the sheet even when it is disposed at an angle against the adjacent sheet by reason of the lowermost sheet being warped, which in conventional feeding structures causes difiiculty. Also, the supplemental feeding means positively holds the separated sheet against upward movement by the sheet engaging parts of the main feeding means. By separating the rear portion of the blank from the stack, the present feeding mechanism reduces friction between the fed sheet and the stack to a minimum, so that the sheet or blank is moved easily and without marring.

One object of the invention is the provision of a sheet or blank feeder which will-operate effectively under varying conditions and without likelihood that a sheet or blank will not be engaged properly. Another object is to provide a sheet or blank feeder that will operate successfully to feed relatively thick sheets even when the sheets are warped or curved and even if the degree of Warping or curvature differs between successive sheets. It is a further object of the invention to provide a supplemental sheet feeding mechanism which displaces the lowermost sheet of a stack of sheets a short distance in the feeding direction for engagement by the main feeding means. Still another object is the provision of supplemental sheet feeding mechanism which lifts the sheets of a stack above the lowermost sheet so that only the lowermost sheet is engaged and fed by the main feeding means. An additional object of the invention is to provide supplemental sheet feeding mechanism which initially feeds the lowermost of a stack of sheets a short distance in the feeding direction and simultaneously swings the lowermost sheet downwardly away from the rest of the stack while supporting the remaining sheets in the stack against downward movement, to assure that only the lowermost sheet is engaged by the main feeding means. Another object is the provision of supplemental sheet feeding mechanism that initially feeds the lowermost of a stack of sheets in the feeding direction a short distance to a position for engagement by the main feeding means while simultaneously swinging the sheet downwardly away from the stack and moving the rear portion of the rest of the stack upwardly away from the lowermost sheet so that only that sheet can be engaged by the main feeding means. It is also an object of my invention to provide supplemental sheet feeding mechanism which while imparting initial feeding movement to the lowermost sheet of a stack separates the greater portion of the sheet from the stack to reduce friction in the feeding of the sheet.

Other and further objects, advantages and features of the invention will be apparent to those skilled in the art from the following description, taken with the accompanying drawings, in which:

Fig. l is a fragmentary side elevational view of a sheet or blank treating machine incorporating one embodiment of the invention;

Fig. 2 is a horizontal sectional View taken substantially as indicated by the line 22 of Fig. 1;

Fig. 3 is a vertical sectional view taken substantially along the line 3-3 of Fig. 1;

Fig. 4 is an enlarged side elevational view of one of the supplemental feeder elements; and

Fig. 5 is an enlarged side elevational view of one of the supplemental feeder elements and an engaging element of the main feeding means in their positions as the feeding of a blank is taken over by the main feeding means.

The invention is disclosed as embodied in a structure for feeding corrugated paperboard container blanks to folding and stapling apparatus, but only by way of example and illustration, since the invention is applicable to the feeding of sheets or blanks of other materials and to other kinds of sheet treating devices or machines.

Referring to the drawings, there is shown in Fig. 1 the rear portion of a paperboardcontainer blank folding and stapling machine comprising a frame generally designated by reference numeral I and having a hopper or magazine H for a stack S of blanks B. The hopper is defined by a plurality of adjustable back stops [2 in the form of plates inclined upwardly and rearwardly, and a plurality of gates 13 and a pair of side gauges it, best shown in Fig. 3, similarly inclined and mounted on a carriage l extending across the frame l0 forwardly of the stops and adjustable lengthwise of the frame. The gates l3 are vertically adjustable by means of handwheels l 6 or the like to accommodate blanks of different thicknesses, and the side gauges M are adjustable transversely of the frame to correspond to the appropriate dimension of the blanks. The blanks are fanned out by the inclination of the hopper parts, and in addition are disposed slanting downwardly and forwardly. The forward part of the stack restson blank-supporting rails ll extending longitudinally of the frame It, and the rear end of the stack is supported above the rails by supplemental feed means described hereinafter.

Forwardly of the hopper, the machine has a vertical folding station comprising a pair of vertical folder plates l3 adjustable transversely of the frame Hi and a pair of helical folders 19 on short horizontal shafts 20 journaled in suitable blocks mounted on the frame. The folders are arranged to engage the underside of a blank brought to the station and by reason of their shape and rotation swing the exterior panels ofthe blank upwardly against the folder plates. Each folder is adjustable transversely of the frame It by means of a screw [9a carrying a mounting member I92) for the folder (Fig. 3). Other stations for performing operations on the blanks are preferably incorporated in the machine, a horizontal folding station and stapling station being employed with the illustrated machine. Such additional stations are not shown, since they may vary as desired in number, function and structure, and the vertical folding station has been shown and described only by way of example or illustration. It is to be understood that the invention is not limited to feeding mechanism for a machine performing any particular operation or operations on the blanks or sheets fed thereto.

Below the rails I1 is a shuttle frame or carriage 21 reciprocable longitudinally of the frame It on suitable bearings (not shown) for moving the blanks through the machine. The shuttle frame is shown as comprising a pair of longitudinally extending members 22 connected at intervals by pairs of transverse rods 23 and a transverse pivot bar 2'4. On each pair of rods 23 .is mounted a pusher 25 formed of a plate bent to provide a vertical forward portion and an inclined rear portion curved about the rear bar of the pair to pivot the pusher thereon. The pusher is biased upwardly by a spring 26 in the form of a resilient strip bent about the pair of bars 23 and engaged with the pusher which is thus normally held with the forward portion projecting above the upper surface of the rails ll so that it may engagethesrear edge of a blank B supported on the rails.

The rear end of the shuttle frame 2 I, which is disposed below the hopper H upon rearward movement of the shuttle frame, has a transverse plate 2! projecting laterally beyond the longitudinal members 22 and carrying hinge brackets 28 by whicha plurality of feed or picker plates 29 are pivoted at their forward ends to the shuttle frame. The feed plates 29 extend rearwardly beyond the shuttle frame, and each has its upper surface provided with an abutment or picker element proper 30, preferably higher than the thickness of the blanks and somewhat undercut, for engaging the rear edge of the blank to be fed. The abutment may be provided by a replaceable plate 3|. Each feed plate has a projection 32 depending from its bottom surface to bear on a spring cam 33 for raising the :feed plate against the lowermost blank as the feed plates are moved rearwardly under the hopper. The-spring cams 33 .are in the form of resilient strips extending longitudinally of the frame H] with their forward ends secured to a transverse strip v34 :mounted on the frame somewhat forwardly of the hopper. The earns 33 extend gradually upwardly from their forward ends and have their rear ends yieldingly supported, in this case by bent resilient strips 35 extending forwardly from the rear of the frame it. The forward end of each strip 35 extends under the rear end'of one of thespring cams 33, and a bolt 38 extends through suitable apertures in the overlapped ends to loosely couple these parts. The lower end of'the bolt projects downwardly through a bracket 3'! on the frame and has a .pair of lockednuts 38 on its lower end to limit upward movement of the spring cam 33.

The shuttle frame 2| is reciprocated by a feeder bar 39 disposed therebelow and extending longitudinally .of the :frame l0 and connected 5. at its forward end to the shuttle frame by an upward projection 40 secured to a yoke member all pivotally mounted on the pivot bar 24. At its rear end, the feeder bar is pivotally connected to the upper end of a walking beam 42 the lower end of which is pivoted in suitable pillow blocks :23. The rear end of a connecting rod 44 is pivoted to the center of the walking beam, the forward end of the connecting rod being pivotally connected to a crank 45 on a crankshaft 4B suitably journaled in the frame It]. counter weight 4'! is provided for the crank. The crankshaft is driven by a sprocket chain 43 or the like from a clutch shaft 49, which in turn is driven by a motor 50 through a speed reducer 5i, belt 52 and clutch 53, in this case a magnetic clutch. A jackshaft 54 is driven from the crankshaft 48 by a sprocket chain 55 or the like, and the shafts 29 of the folders [9 are driven from the jackshaft by suitable chains or other means. Other elements of the machine may similarly be.

driven from the jackshaft, and it will be obvious that the other parts of the machine thus operate in timed relation to the crank 45.

Supplemental sheet picker or feeding mechanism is provided at the rear of the machine to assure positive feeding of one and only one blank B from the bottom of the stack S on each feeding movement. This mechanism comprises a rock shaft 55 extending transversely of and suitably journaled in the frame l below and at the rear of the hopper H. A rocking lever 51 extends downwardly from the rock shaft 56, with its upper end fixed to the rock shaft by a key 53 or the like. At its lower end the lever 51 is pivotally connected to the rear end of a link 59 the forward end of which is pivoted to the walking beam 42 above the lower end thereof. A plurality of feeder dogs or picker members 60 are spaced along the rock shaft laterally offset from the paths of the feed plates 29, and extend upwardly to the bottom of the hopper H at the rear thereof. The dogs are generally L-shaped, with two arms and t2, the arm 6! extending upwardly from the rock shaft 56 and fixed on the shaft by a key 63 or the like. The other arm 62 extends more or less horizontally at the upper end of the dog. The arm 62 is divided into a forward portion 64 which slopes downwardly and forwardly, and a rear portion 65 which projects radially outwardly,

or, in other words, upwardly, somewhat beyond the portion 64. This stepped arrangement provides a shoulder or abutment 66 providing a picker element proper at the upper surface of the feeder dog 69. In the rearmost position of the dog, the forward portion 64 engages under the lowermost blank of the stack S to support the rear portion thereof above the level of the rails ll, and the abutment 66 is spaced slightly behind the rear edge of the lowermost blank. The height of the abutment 66 is not greater than the thickness of the blanks, and preferably is slightly less than such thickness. Preferably also, the abutment is slightly undercut. In the present embodiment, the abutment 66 is provided by an insert plate 61 which fits into a recess 68 formed in the upper surface of the feeder dog, and secured by screws or the like. of different thickness may be employed with various blank thicknesses. The rear portion 65 of the arm 62 is so formed that upon rocking of the dog at least a part of its surface describes an' arc of slightly greater radius than the arc of the abutment 66, with a substantially camming movement.

A suitable.

Thus plates In operation, as the crank is rotated by the driving means, the feeder bar 39 is reciprocated longitudinally of the frame ID by means of the connecting rod and walking beam, and. moves the shuttle frame 2| back and forth. In the rearmost position of the shuttle frame, the feed plates 29 have their abutments 30 engaged with the rear edge of the lowermost blank of the stack S, and the pushers 25 are slightly to the rear of the several stations. Upon forward movement of the shuttle frame, the feed plates draw the lowermost blank under the gates [3 on the rails IT to the vertical folding station, while the first pusher forwardly of the feed plates engages the rear edge of any blank at the vertical folding station and moves it to the next station, and the next pusher similarly moves any blank at that next station to a more advanced station. Upon return movement of the shuttle frame, the feed plates 29 move back under the stack of blanks and are urged upwardly by the spring cams 33 against the under surface of the now lowermost blank, so that the abutments 30 move upwardly beyond the plane of the blank as they move past the rear edge thereof. At the same time, the pushers 25 are carried rearwardly and move beneath any blanks in. their path, being depressed as the inclined rear surface of each engages the forward edge of the blank, and being raised by their springs 26 as they pass the rear edges of the blanks. The feed plates and pushers are thus brought back to their rearmost positions ready to move the blanks forwardly upon the next forward movement of the shuttle frame. During rearward movement of the shuttle frame, operations may be performed upon the blanks at the several stations.

The supplemental feeding mechanism serves to move the lowest blank of the stack to a point corresponding to the rearmost position of the feed plates 29 so that it will be engaged thereby and its feeding completed. As already pointed out, in their rearmost, substantially vertical, position the feeder dogs support the stack S at r the rear, and the abutments 66 and rear surface portions are behind the stack. By reason of the connection of the rock shaft 56 to the walking beam 42 through the rocking lever 51 and link 59, the feed dogs are swung forwardly as the shuttle frame 2i is moved rearwardly, and as the shuttle frame moves forwardly the dogs are swung rearwardly. In Fig. 4, one of the feeder dogs 60 is shown in its rearmost position in full lines, and in its foremost position in dotted lines.

As the dog moves from the full line to the dotted line position, the abutment 66 catches the rear edge of the lowermost blank, which is resting on the forward portion 64 of the arm 62, and moves it forwardly toward the rearwardly-moving feed plates 29. Since the abutment moves in an arc about the rock shaft, the rear portion of the blank is moved downwardly away from the stack as well as forwardly, and is held against possible upward movement, for example by the action of the feed plates, 29, as later explained. In addition, the

gamma;

This lifting isrelatively slight in the embodiment shown, but it will be obvious that by increasing the upward projection of the, portion 65?, or oth-- erwise changing its configuration from that disclosed, its camming or lifting effect can-easily be increased. On the other hand, the lifting of the stack may usually be dispensed with, the separa tion of the blank from the. stack merely by the downward swinging of the blank. being sufficient. to achieve the desired purposes. The shape of the portion 65 may therefore be changed so. that it merely engages under the stack without. any lifting action. When the feeder dog is swung back to the full line position from the dottedline position, the stack drops off the rear portion onto the forward portion 6.4, bringing the next blank into position to be engaged by the abut, ment. 66 upon the next forward movement. of the dog.

The feed plates 29 of course move rearwardly with the shuttle frame 2i as the feeder dogs 60 swing forwardly and down. The movements are so timed that as the dogs reach their forward limit of movement the feed plates reach their rearmost position, with their abutments 30. just behind the rear edge. of the blank which has. been advanced by the dogs. The feed plates, being urged upwardly by the spring earns 33 through the projections 32, engage against the lower surface of the, lowermost blank, but any force they may thus exert on the blankto. move it upwardly is overcome by the downwardly acting force of the dogs 60 on the blank. Under the action of the spring cams, the feed plates move to. a position in which the abutments 38 project. above the lowermost blank, so that upon forward movement of the feed plates the abutments catch the rear edge of the blank and carry it forwardly to the first. operating station. The feeding of the blank is thus taken over by the feed plates from the feeder dogs. In Fig. 5, one of the feeder dogs and one of the feed plates are shown in their positions at their respective described limits of movement, as the feed plates take over the feeding of the blank. As already explained, the. dogs. and feed plates are spaced laterally from each. other. From their positions as shown in Fig. 5., the dogs 6!] move rearwardly and the feed plates 29 move forwardly, to complete the feeding cycle and again return to the take-over point.

It will be seen that the action of the feederdogs 6d inseparating the lowermost blank from the stack S positively assures that the feed plates 29, will engage properly with the rear edge of the blank so that it will be fed to the machine. It also prevents the feeding of more than one blank at one time, since the feed plates do. not engage the stack as such but only the blank ad--' vanced to the take-over point by the feeder dogs, and the latter can engage only a single blank because of the restricted height of their abutments. If a blank is warped so that its rear edge is directed toward the blank next above, the feed plates if used as the sole feeding means might be unable properly to engage the rear edge because the downwardly bulged blank might hold them at too great an angle for the abutments to. catch the blank edge. The feed dog abutments, however, readily engage the edge of a warped blank because they move close to the blank next above the lowermost, and further, the engagement of the warped blank on the forward surface portion 64 has a flattening effect on the blank. The feeder dogs are eifective even when-different blanks are warped or curved varying degrees.

The dogs positively force the bottom sheet downwardly, permitting faster and more certain feeding than if downward movement of the blank were accomplished, for example, by gravity, and preventing any upward movement of the sheet. The supplemental feeding mechanism has another advantage over conventional sheet feeding means in that the separation from the stack of the, blank being fed reduces the friction which must. be overcome by the feed plates in drawing the blank onto the rails ll clear of the stack. There is therefore. less strain on the machine parts and less likelihood of the blanks being damaged or marked by the feed plates.

Although the invention has been disclosed as incorporated in a machine for treating corru gated paperboard container blanks, it is apparent thatit may be employed in the feeding of sheets of other materials and having substantial thickness and rigidity, for example sheets of metal or plastic. Furthermore, the inventive principle may be applied to the feeding of sheets of slight thickness or or" less rigid materials.

Many changes may be made in the disclosed embodiment without departing from the principles of my invention, and 1 therefore do not intend that the invention be limited otherwise than as required by the spirit and not merely the literal scope of the appended claims.

I claim:

1. In a machine of the character described including a magazine adapted to contain a stack of sheets and having means for supporting the forward end of the stack, sheet feeding mechanism for repeatedly withdrawing the lowermost sheet in said stack and feeding the same forwardly therefrom, a horizontally reciprooable carriage movable between forward and rear positions, a first sheet picker element movably mounted on said carriage and movable bodily with the carriage from an advanced position to a, retracted position wherein it underlies said magazine within the vertical confines of the latter and is positioned forwardly of the rear edge of the lowermost sheet in the stack, cam means positioned in the path of movement of said picker element for engaging the latter and elevating the same into engagement with a sheet withdrawnfrom the stack and positioned thereabove, a second and oscillatable sheet picker element offset laterally from said first element for initially dislodging the lowermost sheet in the stack and depositing the same above said second picker element and in the path of movement of the latter, said second picker element being movable in an arcuate path between a retracted position wherein it assumes a position behind the rear edge of the lowermost sheet in the stack above the level of the first picker element to an advanced position wherein it is slightly forward of the first picker element, and means for moving reciprocable carriage and oscillatable picker element in timed relation and in opposite directions.

2. In a machine of the character described including a magazine adapted to contain a stack of sheets and having means for supporting the for ward end of the.v stack, sheet feeding mechanism for repeatedly withdrawing the lowermost sheet in said stack and feeding the same forwardly therefrom, a horizontally reciprocable carriage movable between forward and rear positions, a first sheetpicker element movably mounted on said. carriage and movable bodily with the carriage from an advanced position to a retracted position wherein it underlies said magazine within the vertical confines of the latter and is positioned forwardly of the rear edge of the lowermost sheet in the stack, cam means positioned in the path of movement of said picker element for engaging the latter and elevating the same into engagement with a sheet withdrawn from the stack and positioned thereabove, a second and osciliatable sheet picker element ofi'set laterally from said first element for initially dislodging the lowermost sheet in the stack and depositing the same above said second picker element and in the path of movement of the latter, said second picker element being movable in an arcuate path between a retracted position wherein it assumes a position behind the rear edge of the lowermost sheet in the stack above the level of the first picker element to an advanced position wherein it is slightly forward of the first picker element, and means for moving said reciprocable carriage and oscillatable picker element in timed relation 10 and in opposite directions, said picker elements each presenting a forwardly facing shoulder designed for engagement with the rear edge of the sheet withdrawn from the stack, said shoulders each being undercut to confine said latter edge during sheet impelling operations.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,031,251 Dixon July 2, 1912 1,643,646 Swift Sept. 2'1, 1927 1,725,400 Last Aug. 20, 1929 1,756,073 Swift Apr. 29, 1930 1,823,108 Kurowski Sept. 15, 1931 2,044,707 Lasker June 16, 1936 2,395,496 Nordquist Feb. 26, 1946 2,456,449 Rouan et al Dec. 14, 1948 2,636,733 Lewis Apr. 28, 1953