US3202420A

US3202420A - Vacuum feeding device

Info

Publication number: US3202420A
Application number: US284181A
Authority: US
Inventors: Norman E Dovey
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-05-29
Filing date: 1963-05-29
Publication date: 1965-08-24
Anticipated expiration: 1982-08-24

Description

Aug. 24, 1965 N. E. DOVEY VACUUM FEEDING DEVICE 2 Sheets-Sheet 1 Filed May 29, 1963 INVENTOR NORMAN E. DOVEY ATTORN Aug. 4, 1965 N. E. DQVEY 3,202,420

VACUUM FEEDING DEVICE Filed May 29, 1963 2 Sheets-Sheet 2 7 we 64 so so 7868 FIG 2 58 174 f L1 I52 I I ATMOSPHERE I VACUUM FIG. 4

VACUUM ATMOSPHERE FIGS 20o 2|o VACUUM &\ o O 0g? 0 c ATMOSHERE fo o o o a o O o INVENTOR.

NORMAN E. DOV EY BY wimzias United States Patent 3,2h2,420 VACUUM FEEDING DEVRCE Norman E. Dovey, 1922 Indiana Ave, Anderson, Ind. Fiied May 29, 3963, Ser. No. 284,181 12 Claims, (Cl. 271-32) The present invention pertains to the art of feeding sheets formed from cardboard, paper or the like and more particularly to a vacuum operated device for feeding the bottom sheet from a stack of such sheets.

The present invention is particularly applicable to feeding cardboard sheets from a stack into the feed rolls of a rotary printing or cutting machine and the invention will be described with particular reference thereto; however, it is to be appreciated that the invention has much broader applications and may be used for feeding other sheets, such as metal sheets, into a variety of rotary processing machines.

In the production of cardboard boxes, or other articles formed from such material, it is necessary to apply printed matter or decorative or informative nature onto the cardboard and also to cut and score the cardboard so that the cardboard can be formed into the proper shapes. To accomplish this printing and cutting operation, it is now the usual practice to first sever the cardboard into short sheets, known as blanks, after the cardboard issues from a corrugating machine. Then these blanks are formed into easily handled stacks from which the blanks can be fed, one at a time, into a rotary printing or cutting machine.

These rotary printing or cutting machines usually comprise a pair of cutting or printing rolls rotating at a tremendous speed so that the blanks must be fed between these rolls in rapid succession to process a single sheet on each revolution of the rolls. The cutting of the blanks or the printing thereof as they pass between the rapidly rotating rolls must be done with great accuracy so that the printing or cutting is properly registered with respect to the edges of the blanks. This alignment is extremely important when making successive passes of the blank through different printing rolls each of which is used to deposit a given color onto the cardboard blank which colors must be registered with respect to each other, as well as being properly registered with respect to the edges of the blank. Further, when the cardboard blank is both printed and cut, the two operations must be so controlled with respect to a common point that the printed matter is properly registered with respect to the cuts on the blank. It is seen that the problem of feeding one sheet or blank from the bottom of the stack into the rapidly rotating printing or cutting rolls can pose a substantial problem if the blank must be fed into the roll with great accuracy, i.e., the blank must reach the rolls when a predetermined point on the rapidly rotating rolls is at the entrant end or nip of the rolls.

In the past, it has been common to feed the bottom blank, or sheet, from the stack by providing a push rod that contacts the back edge of the blank and forces the blank toward a pair of feed rolls on the rotary printing or cutting machine. To prevent dragging of the bar across the under surface of the blanks as the bar was retracted from the rolls, it was common to provide a complicated lever arrangement for controlling the movement of the bar so that the bar was moved in a plane adjacent the stack on the feeding portion of the cycle and would move in a plane substantially below the stack on the retracting portion of the cycle. This lever arrangement substantially increased the bulk of the feeding device and led to many maintenance difficulties. in addition, in feeding the blank toward the feed rolls, the leading edge of the blank must be registered with the rolls; however, since ice the push bar contacted the rear edge of the blank, there was no assurance that the leading edge would be properly positioned with respect to the rolls. To the contrary, if the size of the blank was not accurately controlled, which is often difiicult, or if the blank was warped, which is often the case, the leading edge of the blank was inaccurately positioned with respect to the feed rolls and the requisite alignment of the blank was not realized. Further, since the blanks are often quite thin, the bar often missed the rear edge of the bottom blank and caused a radically misalignment of the blank and feed rolls. From these disadvantages, it is seen that such a prior feeding device would require a substantial amount of adjustment and result in a substantial amount of scrap.

To correct these problems, it has been suggested to provide a series of vacuum cups which are mounted in a frame supported on a complicated lever mechanism so that the cups move along the bottom of the stack in the feeding portion of the cycle and move along a path spaced substantially from the bottom of the stack on the retracting portion of the cycle. Such vacuum cups required a substantial amount of vacuum from a pump positioned adjacent the feeding device which increased the cost of feeding the blanks into the rotary printing or cutting machine. Further, the vacuum cups often slipped along the surface of the blanks which would cause erroneous alignment of the blanks with respect to the feed rolls.

The present invention is directed toward an improved vacuum feeding arrangement which does not require a complicated linkage mechanism for shifting the device back and forth beneath the stacks of blanks and which -a sures that the feeding device does not slip with respect to the blank being fed toward the feed rolls.

In accordance with the present invention there is provided a reciprocative shuttle movable in a feeding direction and in a retracting direction for feeding the bottom blank or sheet from a stack of blanks comprising: an upper surface on the shuttle, a head having a friction increasing, large area gripping surface, means for creating a vacuum adjacent the gripping surface to pull the grippin surface against the lower side of the bottom blank, and means for shifting the head below the upper surface of the shuttle at least while the shuttle is moving in the retracting direction. The shuttles upper surface is preferably below the surface on which the blanks are supported and on which they slide as they are pulled toward the rotary machine.

The primary object of the present invention is the provision of a reciprocative device for feeding the bottom blank, from a stack of blanks, into a rotary machine such as a printing or cutting machine which device is inexpensive to produce and install and is durable and accurate in operation.

Another object of the present invention is the provision of such a reciprocative feeding device which device grips the blank with a vacuum caused force.

Still another object of the present invention is the provision of such a reciprocative feeding device that has a combined friction and vacuum gripping arrangement to assure accurate feeding of the blanks into the rotary machine.

Yet another object of the present invention is the provision of a reciprocative device for feeding the bottom blank from a stack of blanks into a rotary machine such as a printing or cutting machine which device is not affected by warping or variations in the size of the blanks.

Still another object of the present invention is the provision of a device as defined above which includes a shuttle having an upper surface and movable in a plane beneath the blanks and a vacuum head movable from a position above the upper surface while the shuttle is moving in the feeding direction to a position below the upper surface while the shuttle is moving in the retracting apparent from the following description used to illustrate the preferred embodiment of the present invention as read in connection with the accompanying drawings in which:

FIGURE 1 is a side elevational view showing, somewhat schematically, the preferred embodiment of the pres:

' ent invention;

FIGURE 2 is a fragmentary, enlarged cross-sectional view illustrating the preferred embodiment of the present invention;

FIGURE 3 is a further fragmentary, enlarged view illustrating a further portion of the preferred embodiment of the present invention;

FIGURE 4 is a fragmentar cross-sectional view similar to FIGURE 2 illustrating an operating position of the preferred embodiment of the present invention; and,

FIGURE 5 is a schematic block diagram illustrating the operation of the valve for controlling the preferred embodiment of the present invention.

Referring now to the drawings, wherein the showings are for the purpose of illustrating the preferred embodiment of the invent-ion only, and not for the purpose of limiting same, FEGURE 1 shows a stack A of sheets or blanks .113

which have been previously cut to the desired length which stack is supported within a cage 12 on the upper flat, support surface 14- of table B. Forward of the surface 14 there is illustrated a pair of feed rolls 16, 18 which are the feed rolls of a rotary printing or cutting machine for processing the blanks 10. To support the blanks as they issue from the pinch rolls, there is illustrated an apron 2d; however, it is appreciated that the feed rolls 16, 18 may be the actual printing or cutting rolls of the rotary machine. It is further appreciated that if the rolls 16, 18 are used only for the purpose of feeding the blanks into a subsequent pair of printing or cutting rolls, the apron 20 may or may not be provided. To allow removal of only the bottom blank 16} from stack A, there is provided at the forward end of cage 12 a plate 22 which is adjusted in the vertical direction to provide a slot 24 between surface 14 and plate 22 which slot is so adjusted to have a greater thickness than one blank anda lesser thickness than two blanks.

In accordance with the invention, there is provided a device for feeding the bottom blank 11) supported on surface 14 in a generally horizontal direction into the nip of rolls 16, 18 so that the rolls can feed the blank through the rotary printing or cutting machine. The timing of the instant at which the blank it) enters the rolls is critical to proper longitudinal alignment of blank 19 through the rotary machine. indicated as C and includes, as its primary feature, a shuttle 30 having a casing 32 which is preferably formed from cast light metal, such as aluminum, to reduce its weight and which casing has on opposite sides thereof a V-shaped side to be received within a guide means 34 which is a V-shaped groovematching the V-shaped sides of the casing 32. Since a variety of guide means such allow reciprocation of the shuttle within the guide means 34 so that the shuttle moves in a plane substantially parallel to the bottom blank 18 in both a forward and a reverse direction.

The feeding device is A variety of mechanisms could be provided for reciproeating shuttle 30 within the guide means 34-; however, in accordance with the illustrated embodiment of the present invention, the operating mechanism is schematically disclosed as including a bracket 40 connected to the under side of shuttle 36 which bracketsupports a journal pin 42. 'Beneath the shuttle 39 there is provided a lever 44 having a slot 46 adapted to receive pin 42 and pivotally mounted by a bracket 48. For oscillating the lever 44- in a first direction indicated by arrow a and then in a second direction indicated by arrow [2, which are the feeding direction and the retracting direction, respectively, of shuttle 30, there is provided a connecting rod 50 securcd onto the lever 44 :at one end and onto the driven disk 52 through adjustable bracket 54 on the opposite end. Accordingly, rotation of the disk 52, by means not here illustrated, the lever 44 is oscillated back and forth to shift shuttle 3d backand forth within the guide 'means 34 toward and away from the feed rolls 16, 13.

The adjustment of bracket 54 determines the amount of forward movement of the shuttle 30 so that the movement of the shuttle in the forward direction can be accurately controlled with respect to the, spacing of plate 22 wherein shuttle casing 32 has an upper surface 58 which.

is generally aligned with or slightly below the blank sup porting surface 14 of table B. By so aligning the upper surface 53 with respect to surface 14, the shuttle may be reciprocated back and forth within the guide means 34 without protruding outwardly beyond the upper surface 14. Accordingly, as the 'shuttle'is moving backwardly in direction b there is notendency for the shuttle to come in contact with the leading edge of the lower blank 1'9. 1

Within the casing 32 there is'provided a head 69 received within a threaded bore 62, best illustrated in FIG- URE 3. The head includes a cap 64 having an annular groove 66 which groove defines an upper flange 68 and a lower flange 743. At the lower. end of the cap 64 there is with any of a variety of friction increasingmeans such as knurling, which not only will allow an increase in the friction gripping characteristics of the surface 8t) but will also allow rapid equalization of the pressure along the surface even when the surface is in contact with the lower side of a blank 1%.

The underside ofcap 64 is connected onto a stem having a shank 91 and a threaded nose 92 received within the threaded bore 72 of cap 64; Below the nose 92 there is provided a flange 94 having an annularly extending diaphragm receiving recess 96. Spaced below flange 94 is a radiused shoulder 98, the purpose of which will be hereinafter described in'detail. Spaced longitudinally on shank 91 there is provided annularly extending grooves 199, 102 which are communicated with a central bore 104 by radially extending connecting passages 196, 168, respectively. The end of shank 91 terminates in a stud 11%..

Surrounding the shank 91 there is provided in phragm which assists in connecting stem 90, and thus head 60, onto the casing 32. To lock the diaphragm 124 into place against the shoulder 98, there is diaprovideda'lock sleeve 122 slidably received upon the;

5 shank 9i and held in place by a washer 124 and a nut 126 coacting with the stud lid. Reciprocal movement of the sleeve 122 within bore $27 of the casing 32 is facilitated by Teflon sleeve bearings 12% which require, under normal use, no lubrication. The sleeve 12?; is provided with radially extending passages 129, 13% which communicate with annular passages Mitt, 1&2 respectively.

To seal the end of shank 91?, there is provided a threaded boss 131 on casing 32 and an accordion diaphragm 132 held onto boss 131 by a cap 134 and secured onto the shank 91 by a washer 136 clamped between washer 12 iand t e nut 12%. This accordion diaphragm 132 is communicated with the central bore 104 so that the pressure at the end of the shank is somewhat identical to the pressure within the bore 104. This prevents creation of vacuum or pressure pockets at this one of the stem which pockets could adversely affect the operation of head 62 i secure the diaphragm 12% within bore '72, there is provided a threaded clamp ring 1 i] having an upper radiused shoulder 142 and a lower clamping shoulder 1 54 which lower shoulder clamps the outer edge of the diaphragm 12% with respect to the casing 32.

Above the diaphragm 12% there is provided an intermediate diaphragm 15h held in place against ring 149 by a threaded clamp ring 1 2 so that the diaphragms 12d and define a chamber lot Adjacent the upper portion of threaded bore '72, there is provided an upper diaphragm 17% held against ring by a threaded clamp ring 172. The diaphragm is received within the recess 66 and includes a folded porlion i74 extending radially outward from the recess along the lower edge of flange 68 and terminating in a lip por tion 176 extending upwardly beyond the surface 8% when it assumes its normal position. To hold the diaphragm 17% within groove 66, the actual set of the diaphragm can be utilized or, as illustrated, the diaphragm can be held within the groove by a snap ring 178.

Referring now to the fluid system incorporated within casing 32, as is shown in FIGURES 2-4, the chamber 16$ is communicated with a passage 18% provided within the casing 32 which passage is in turn connected to a coupling -82. An annular recess 186 is provided around sleeve 122 to communicate the passage 129 with a passage 158 within the casing 32 which latter mentioned passage is connected to a coupling 19% similar to coupling 132. These couplings provide the external connecting means for joining the fluid system within the reciprocally mounted shuttle 36 as is best shown in FiGURE 1.

Referring now more particularly to FIGURE 1, and also to EGURE 5, there is provided on the lower side of table B a valve 2% which may take a variety of structural embodiments; however in accordance with the illustrated embodiment of the present invention, the valve includes a central valve member, not shown, driven by sprocket which sprocket is connected to a like sprocket driven by disk 5. The sprockets 202 and 234 have a like diameter so that the central valve member within valve makes one revolution as the disk 52 revolves once. The intake of the valve includes a vacuum supply line 21b directed through a filter 212 to juxtaposed vacuum supply line and a pressure supply line 2.1 which in accordance with the preferred embodiment of the present invention, is an atmosphere line having a filter 216 and an intake 218. The outlet of valve includes line 22% connected onto coupling 182 and line 22-22 connected onto coupling 1%. The lines 224 and 222 are so dimensioned that they allow easy reciprocation of shuttle 3t without disconnecting the lines from the shuttle.

The central valve member within valve 290 is controlled by sprocket 232 in a manner schematically represented in FIGURE 5 wherein the dash lines indicate the connections between the inlet and outlet lines of the valve 2% when the shuttle is moving in the feeding direction a and the dotted lines indicate the connections between the inlet lines and the outlet lines when the shuttle is moving in the retracting direction b. Of course, the sprocket 202 is controlled by the sprocket 2% so that the connection indicated by the dotted lines of FIGURE 5 will be in effect at the very end of the forward travel of shuttle 349 so that the shuttle will release the blank just prior to its being pulled by the rolls 16, 18. Also, the connection indicated by the dashed lines in FIGURE 5 may not be made until just after the forward movement, or movement in the feeding direction a, has been commenced. The slight changes in the exact time when the valve will switch from one position to the other can be determined by adjusting the angular position of the sprocket 292 with respect to the central valve member within the valve 2%. Such minor adjustments are within the skill of the art and it is basically the contemplation of the present invention to have the connections as indicated in FIGURE 5 by the dash lines in effect during a major portion of the movement of shuttle 39 in the feeding direction and the connections as indicated by the dotted lines in efiect during all of the time when the huttle 36 is being retracted.

In operation of the apparatus C, the lever 44 is oscillated back and forth by disk 52 so that shuttle Bill is reciprocated within guide means 341. When the lever 44 is moving in direction a as shown in FIGURE 1, the sprocket 2&2 has shifted the valve 22th? so that the connections indicated by the dashed lines of FIGURE 5 are in effect which situation is illustrated in FIGURE 2 wherein a vacuum is present within central bore M41- and atmosphere or pressure is applied to chamber foil. In this condition, the head so is forced upwardly into engagement with the underside of the lowermost blank 10 in stack A. As the head 60 is forced against the underside of blank 1% the lip portion 176 forms an annular chamber to subject the under surface of the blank with a vacuum within the area defined by lip 176 which vacuum forces the head 6t? into tight engagement with the underside of the blank so that the friction increasing means on the surface 39 actually bites into the underside of blank 10 so that the blank is held with respect to the shuttle 3G by the combined action of the vacuum and the friction increasing means.

When a knurl is provided on the surface 8% as is contemplated by the preferred embodiment of the present invention, the vacuum can spread over the entire surface 39 to form an equalized vacuum area at surface 31' which equalized vacuum area assists in the gripping action of the knurled surface. The radial extending passages 78 assist in this even distribution of the vacuum. It is appreciated that by providing this easy communication be tween bore iiiand the surface 8%, the action of the vacuum is substantially instantaneous and the head 66 grips the underside of blank Iii quickly on response to a vacuum within the bore 164. The atmosphere or pressure Within chamber 160 assists in the upward movement of head 60 which upward movement is beyond the surface 53 of the shuttle and slightly beyond the upper surface 14 of table B. In this position, the shuttle 3a is moved in the direction a to deposit the leading edge of the blank llil into the nip of feed roll l6, 18 so that the blank can then be pulled through the rotary printing or cutting machine.

After, or just prior to, the instant when the rolls 16, 18 have started pulling the blank it through the rotary machine, the valve Ziiil is shifted into the position indicated by the dotted lines of FIGURE 5, in which position, the vacuum line 210 is connected to outlet line 229 and thus, to chamber 1m; and the atmosphere or pressure line 214 is connected to outlet line 222 and, thus, to the central bore 104. When this condition exists, a vacuum is created within the chamber tea which pulls the head 64? away from the blank iii so that the lip 176 and the surface are below the surface 58. To assist in this retracting operation, the atmospheric communication with bore 104 'vents this bore and immediately releases the surface 80 from the underside of the blank it). Again, the passages 7% and the multifarious passages caused by the knurling of surface 80 allows rapid response to the atmosphere pressure within or the venting of bore 1% to instantaneously release the blank it from the surface 8%. It is appreciated that the passage 130 prevents trapping of pressure or vacuum within the accordion diaphragm 132.

As the lip 176 and surface 86 is retracted below the surface 58, the shuttle 36 can be moved in the direction b along guide means 34 without scraping or otherwise contacting the leading edge of blank or the underside of the blank as the shuttle is pulled across the blank. It is most important that the lip and surface 80 be below the blank 16 when the head 6%) isrpassing over the leading edge of the blank.

By connecting the valve 2% directlyonto thedisk 52, there is provided a convenient way of synchronizing the operation of the valve with respect to the position of shuttle 39 within the guide means 34. It is Within the contemplation of the present invention, to connect such a valve 2% onto various other devices for sensing the position of shuttle 30 with respect to the guide means 34. For instance, there could be limit switches which would shift the position of valve 2% as the shuttle approached the forwardmost position and the rearwardmost position, respectively. Further, there could be a rack and pinion connected between the valve 2% and'shuttle 30 for controlling the connection of the various pressure lines to the interior of casing 32.. It is further appreciated that, in accordance with the present invention, the valve is controlled in response to the positions of the shuttle.

The present invention has been discussed in connection with the preferred embodiment thereof; however, it is appreciated that various structural changes may be made without departing from the intended spirit and scope of the present invention as defined in the appended claims. For instance, the intermediate diaphragm 150 could be removed without disabling the operation of the feeding device.

In practice, a plurality of these shuttles 3d are positioned transversely across table B. The individual shuttles may be joined together and operated by one lever ii or they may be operatedby synchronized individual levers or other arrangements. The number of shuttles across the table may be varied without departing from the intended scope of the present invention.

Having thus described my invention, I claim:

1. A reciprocative shuttle movable in a horizontal feeding direction and in a retracting direction for feeding in a horizontal direction the bottom sheet from a stack of sheets, said shuttle comprising: a head having a generally flat gripping surface generally parallel with said bottom sheets, first means for creating a vacuum adjacent said gripping surface to pull said gripping surface upwardly against said bottom sheet, second means for shifting said gripping'surface downwardly below the under surface of said stack at least while said shuttle is moving in said retracting direction and under the leading edge of said bottom sheet, and said gripping surface having a knurled surface to increase the gripping force between said bottom sheet and said gripping surface. a I v 2. An apparatus for feeding the bottom sheet from a stack of sheets comprising, in combination: a fixedly 'mounted guide means mounted below and generally parallel to said bottom sheet, a shuttle mounted on said guide means and having an upper surface spaced only slightly from said bottom surface, means for moving said shuttle along said guide means beneath said stack in both a horizontal feeding direction and a horizontal retracting direction, and a sheet gripping device mounted on said shuttle, said device comprising a head reciprocally received in a recess on said shuttle and having a stem extending into said shuttle for guiding said head while it reciprocates, said head having a gripping surface, means for limiting the upward protracted position of said head, a passage in said stem and directed to a port means adjacent said gripping surface, a first valve means for directing a vacuum tosaid passage when said shuttle is moved in the feeding direction to pull said gripping surface into contact with said sheet, second valve means for venting said passage when said shuttle is moving in said retracting direction'and means responsive to the venting of said passage for shifting said gripping surface below said upper surface.

3. An apparatus as defined in claim 2 wherein said gripping surface has an irregular finish to increase the gripping force between said sheet and said gripping surface.

4'. An apparatus as defined in claim 2 including a vacuum sealing lip surrounding said gripping surface and defining an annular chamber around said head, said lip being in sealing engagement with said sheet when said gripping surface is pulled against said sheet.

5. An apparatus as defined in claim 4 wherein said port means includes a plurality of passages extending generally radially outward from said passage in said stem to said annular chamber definedby said sealing lip.

6. An apparatus as defined in claim 5 wherein said port means further includes a generally axial port telniinating generally in the center of said gripping surface.

7. An apparatus as defined in claim 2 including means for operably connecting said first and said second valve means onto a member movable in response to the position of said shuttle to control said first and second valve means. i

8. An apparatus for feeding the bottom sheet from a stack of sheets comprising: a reciprocally mounted, horizontally movable member, a head having an upper flat gripping surface and a lower stern, said stem mounted in said member to reciprocate along a generally vertical axis, a lip'formed around said gripping surface to define a generally air-tight chamber around said gripping surface when said surface contacts said bottom sheet, first means for selectively communicating a vacuum source to said chamber defined by said lip and second vacuum control means for selectively shifting said surface and lip below said feeding surface.

9. An apparatus as defined in claim 8 wherein said first means includes a valve operable in response to the position of said member.

it An apparatus as defined in claim 8 wherein said second means includes a vacuum operated motor operably connected onto said stem.

11. An apparatus for feeding the bottom sheet from a stack of sheets comprising, in combination: guide means fixedly mounted below and generally parallel to said bottom sheet, a shuttle mounted on said guide means and having an upper surface'spaced only slightly below said bottom sheet, means for moving said shuttle along said guide means beneath said stack in both a horizontal feeding direction and a horizontal retracting direction, and a sheet gripping device mounted on said shuttle, said device comprising a vertically movable head with an upwardly facing gripping surface, said gripping surface having a roughened finish for increasing the gripping force between said surface and said bottom sheet, a vacuum passage communicated with said gripping surface, valve means for communicating a vacuum to said vacuum passage, said roughened surface allowing communication of said, gripping surface with said vacuum even when said gripping surface contacts said bottom sheet, and a lip surrounding said gripping surface to define a substantially air-tight chamber for said gripping surface, said head being movable with respect to said shuttle in response to said vacuum.

12. An apparatus as defined in claim 11 wherein said References Cited by the Examiaer UNKTED STATES PATENTS 11/ 1S Schy1anc1er et a1. 27132 6/39 Dixon 271-26 Pechy 271-32 Perrin Til-32 Labombarde 271-32 Stootnoif et a1. 271-46 Labombarde 27132 ROBERT B. REEVES, Acting Primary Examiner.

RAPHAEL M. LUPO, Examiner.