US 3788637 A
Precut and prescored tray blanks are stacked in a magazine, and pivoted vacuum cup means is adapted to withdraw the lowermost blank from the stack by moving the blank downwardly to a delivery position. Control means is provided for operation of the vacuum cup to move it from and to its pick-up position in engagement with the lowermost blank in the stack, the vacuum cup being vented to atmosphere when it reaches the delivery position. A continuously driven roller is adapted to receive the leading edge of the blank in this delivery position and a back-up roller swings on the axis of the driven roller so as to pinch the blank therebetween and to feed it downstream against a stop. Side guides loosely receive the edges of the blank as it moves against the stop, and inturned end portions of these side guides actually deform the side edges of the blank to hold it into position against the stop where it is engaged by mechanism associated with the tray forming apparatus.
Description (OCR text may contain errors)
[ Jan. 29, 1974 BLANK INSERT MECHANISM FOR FORMING APPARATUS Horst G. Lattke, Middletown, Conn.
 Assignee: Emhart Corporation, Bloomfield,
22 Filed: May 15, 1972 21 Appl. No.: 253,448
Related US. Application Data  Division of Ser. No. 55,643, July 17, 1970, Pat. No.
 US. Cl 271/13, 27l/46, 271/48, 271/102  Int. Cl. B651! 9/14  Field of Search 271/29, 32, 13, 48, 49, 46, 271/58, 59,11,12
Primary Examiner-Richard E. Aegerter Assistant Examiner-Bruce l-l. Stoner, Jr. Attorney, Agent, or Firm-McCormick, Paulding &
Huber  ABSTRACT Precut and prescored tray blanks are stacked in a magazine, and pivoted vacuum cup means is adapted to withdraw the lowermost blank from the stack by moving the blank downwardly to a delivery position. Control means is provided for operation of the vacuum cup to move it from and to its pick-up position in engagement with the lowermost blank in the stack, the vacuum cup being vented to atmosphere when it reaches the delivery position. A continuously driven roller is adapted to receive the leading edge of the blank in this delivery position and a back-up roller swings on the axis of the driven roller so as to pinch the blank therebetween and to feed it downstream against a stop. Side guides loosely receive the edges of the blank as it moves against the stop, and intumed end portions of these side guides actually deform the side edges of the blank to hold it into position against the stop where it is engaged by mechanism associated with the tray forming apparatus.
1 Claim, 4 Drawing Figures PATENTED JAN 2 9 I974 sum 1 0F 3 PATENTED 3.788.637
SHEEI 2 BF 3 FIG. 2
PATENTED JAN 2 9 I974 sum 3M3 FIG. 3
BLANK INSERT MECHANISM FOR TRAY FORMING APPARATUS This application is a division of US. Pat. application Ser. No. 55,643, filed July 17, 1970 and now issued as US. Pat. No. 3,683,755 dated Aug. 15, 1972 entitled Tray Forming Apparatus."
This invention relates generally to machines for forming trays or boxes from precut and prescored blanks, and deals more particularly with a mechanism for feeding the blanks into the tray forming apparatus of such a machine.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of a machine for forming trays from flat blanks, and also shows the magazine at its associated infeed mechanism of the present invention.
FIG. 2 is a plan view of the machine shown in FIG. 1.
FIG. 3 is a vertical sectional view taken on the line 3-3 of FIG. 2.
FIG. 4 is a plan view of the mechanism shown in FIG. 3.
DETAILED DESCRIPTION The tray forming apparatus together with the maga zine for storing the precut and prescored blanks and its associated infeed mechanism are adequately described in the above mentioned U.S. Pat. No. 3,683,755 issued to the same inventor herein Aug. 15, 1972. The tray forming apparatus itself need not be described in detail herein, and therefore the description to follow will deal mainly with the infeed mechanism associated with the blanks from which the trays are to be formed.
Means is provided for feeding blanks to the infeed station of the machine, and as shown in FIG. I said means includes a blank magazine, indicated generally at 70, wherein a plurality of these blanks B,B are stacked one above another so as to be sequentially withdrawn from the lower end of the magazine to be fed into the machine from left to right as viewed in FIG. 1. It will of course be apparent that these blanks might also be fed to the infeed station through an opening 12A in the fixed frame side wall 12 of the machine, or through a similar opening A in the opposite side wall 10 without departing from the scope of the present invention.
The magazine 70 is of conventional construction and comprises at least four corner posts 72,72 at least three ofwhich are adjustably mounted so as to accommodate blanks of various size, and these blanks are preferably stored in a slightly inclined position so as to be readily withdrawn from one side edge before the other to a horizontal position for transfer in a horizontal direction to the infeed station of the machine in a manner to be described. The magazine is supported on an inclined upper table portion 74 of a cantilevered portion of the machine frame 76. The cantilevered portion 76 of the machine frame is joined to the front wall 28 of the machine frame by conventional means and houses the blank withdrawing means to be described.
Means is provided for withdrawing the lowermost blank B in the stack, and preferably said means comprises a pivotally mounted vacuum cup 80 which is adapted to be oscillated between the broken line position shown in FIG. 1 and a blank pick-up position wherein the vacuum cup is located in engagement with the lowermost blank in the stack. Vacuum control means is provided for selectively connecting the vacuum cup 80 to a source of suction or vacuum when the cup reaches the pick-up position referred to and until said cup is returned from the pick-up position to the broken line position shown. The vacuum cup 80 is connected to a vacuum pump, indicated generally at 82, by means of a line 84 which line is normally not vented to atmosphere, but which may be so vented by opening a solenoid valve indicated generally at 86. A limit switch LS-l is provided on the cantilevered portion 76 of the machine frame for engaging a cam 88 located on a rotating shaft 90 continuously driven in one direction by drive means indicated generally at 92 from the primary drive motor 56 mentioned above. The shaft 90 also carries a sprocket for driving a chain 94 which rotates a shaft 96 associated with the lever arm 98 upon which the vacuum cup 80 is mounted. The shaft 96 car ries a crank arm 100 which oscillates in a counterclockwise direction so as to lift the lever arm 98 through a predetermined angular displacement to permit the vacuum cup 80 to sequentially contact the lowermost blank B in the magazine 70 after which the crank arm 100 continues to rotate back to the position shown in said counterclockwise direction in order to cyclically move the vacuum cup 80 through its limited angular displacement for engaging and pulling downwardly by gravity the lowermost blank in the stack. When a blank B has been so withdrawn from the stack, it occupies a horizontal delivery position on a roller 108. The rotary cam 88 then closes limit switch LS-1 causing solenoid valve 86 to open and venting the vacuum within the vacuum cup 80 and hence releasing the blank. Means is provided for feeding the blank from this delivery position to the infeed station described above, and said means will now be described in detail. Still with reference to FIG. 1, the rotary cam 88.also acts upon the depending crank arm 102 of a bellcrank 104 so as to rotate the bellcrank 104 in a counterclockwise direction from the position in which it is shown to a blank engaging or active position wherein a back-up roller 106 operates in conjunction with a continuously driven roller 108 for feeding a blank from the delivery station between these rollers 106 and 108 generally toward the infeed station of the machine. More particularly, when the vacuum cup 80 has withdrawn the lowermost blank from the stack and has moved this blank to the delivery position, the leading edge of said blank will be located adjacent the periphery of the continuously driven roller 108. This roller 108 is continuously driven in a clockwise direction by a drive chain 110 which chain 110 is continuously driven by an auxillary drive motor 112. However, until the vacuum is released to atmosphere by means of the solenoid valve 86 the blank B will remain at the delivery position, with the result that the oscillatory movement of the bellcrank 104 can be timed in relationship to the release of vacuum in the cup 80 so that just prior to movement of the back-up roller 104 from the solid line position shown to its active position, wherein said back-up roller engages the blank B at the delivery position, the vacuum is released by closing of limit switch LS-I. FIG. 2 shows the continuously driven blank feeding roller 108 as comprising a plurality of axially spaced blank engaging rolls 108A carried on a single shaft continuously driven in one direction by the auxillary drive motor 112. A drive chain 114 is entrained on a sprocket associated with this auxillary motor 112 and with the shaft upon which the continuously driven roller 108 is located. This chain 114 also passed over a third sprocket 116 associated with a nylon belt conveyor 118 which serves to feed the blank downstream from the driven and back-up rollers, 106 and 108 respectively, to the infeed station, and more particularly against a fixed stop 120. A pair of fixed guides, 132,132 are supported from the fixed frame of the machine by brackets 126,126. Referring more particularly to FIG. 3, the nylon belt conveyors 118,118 are continuously driven in the direction for carrying a blank to the infeed station and said blank travels between the side guides 132,132 each of which guides is adjustably supported on an angle member 130 connected to the machine frame by the brackets 126,126. Each guide comprises a longitudinally extending spring steel member supported at spaced locations from the angle member by screws 124,124 best shown in FIG. 4. In order to prevent the blank B from bouncing against the fixed stops 120,120 these spring steel guides 132,132 are provided with in-turne d downstream end portions, located slightly upstream of the fixed stops 120,120 and so spaced laterally with respect to one another as to forcibly deform a short segment of the side edge 122 of a blank fed therebetween against the fixed stops 120,120. As a result of so deforming the side edges of the blank B, in the manner suggested in FIG. 4, the blank is prevented from bouncing back from its position against the stops 120,120.
The downstream edge portions of these spring steel guides 132,132 are adapted to be adjusted in a desired position so as to permit the operator of the machine to set them at the desired spacing to assure that the blank B does not bounce against the stops 120,120 and that the blank is accurately located at the infeed station of the machine prior to being engaged by the mandrel 58 as it passes through the infeed station and moves the blank through the machine for forming it into a tray. Adjusting screws 134,134 are carried by the depending web portion of the angle member 130 of each side guide for this purpose, and the inner end of each screw 134 abuts the spring steel flexible guide 132 as best shown in FIG. 3 so as to urge the downstream edge portion of the resilient guide 132 into a desired position against the restraining force of the screws 124,124 which support the guide 132 as described.
Once the blank has been positioned at the infeed station of the tray forming apparatus and with its end flaps in radially spaced relationship with respect to the axis of rotation of the mandrel 58, said mandrel moves upwardly from beneath the blank as best shown in FIG. 1 to engage said blank and move it upwardly against four fixed corner tab deflecting plows. The inner radial edge of the blank is engaged by a pair of pivotally mounted fingers which fold the inner end flap through as the blank is moved downstream by the mandrel. Projecting portions of these fingers also fold the corner tabs through 90 with respect to the inner end flap. A pair of resilient leaf spring elements fold the outer end flaps at substantially the same time. The outer pair of corner tabs are each folded by the above mentioned fixed corner tab engaging plows. Opposed side walls, best shown in FIG. 2 at 10 and 12, have edges associated with the openings best shown at 3821 in FIG. 1 which support all of the foregoing flap folding elements, and also support fixed side flap folding members so arranged as to engage the side flaps of the blank as it travels between the axially spaced side walls. The mandrel moves continuously and carries the now folded tray through substantially 180 of rotation to set the adhesive applied prior to arrival at the infeed station, and an eject cylinder also shown in FIG. 1 punches the tray downwardly so that it drops onto a take-away conveyor.
1. The combination comprising a magazine for storing a plurality of flat blanks in stacked relationship, means for withdrawing the endmost blank from the stack and including a vacuum cup pivotally mounted for limited angular movement from and to a pick-up position in engagement with the endmost case in the stack, means for controlling the vacuum to said cup so that the cup is connected to a source of vacuum when it reaches said pick-up position and while moving from said pick-up position, said cup being vented to atmosphere when it reaches a delivery position angularly spaced from said pick-up position, a continuously driven roller so oriented as to receive the leading edge of the blank in said delivery position, a crank arm pivotally supported on an axis coincident with said driven roller, a back-up roller rotatably supported on said crank arm, cam means for oscillating said crank arm between a blank engaging position wherein said backup roller cooperates with said driven roller to feed a blank downstream from said delivery position, means for stopping said blank at a predetermined location downstream of said delivery position and including an abutment surface for engaging the leading edge of the blank together with side guides for loosely receiving the side edges of the blank, said side guides each including a rigid frame member and a resilient flat sheet supported on said rigid frame, and an adjustment screw provided adjacent the downstream edge of said resilient sheet, said screw being threadably received in said frame member and engaging said flat sheet to urge its downstream end inwardly to deform a blank fed therebetween and to thereby hold the blank in position against said abutment surface.