US3604703A

US3604703A - Sheet-feeding apparatus

Info

Publication number: US3604703A
Application number: US835088A
Authority: US
Inventors: Elmer D Nash
Original assignee: Harris Intertype Corp
Current assignee: Harris Graphics Corp
Priority date: 1969-06-20
Filing date: 1969-06-20
Publication date: 1971-09-14
Anticipated expiration: 1988-09-14

Abstract

The present sheet-feeding apparatus has a plurality of spacedapart transfer belts through which vacuum is applied to the underside of a sheet to enable the transfer belts to move the sheet into a printing press or other machine. A plurality of fingers press the sheet toward the transfer belts to facilitate the application of vacuum to the sheet. In addition, highvelocity jets of air may be directed along the underside of the sheet, alone or in conjunction with the fingers, to form areas of low pressure to enable immediate firm gripping of sheets, thereby resulting in higher speed operation and production of the machine.

Description

United States Patent Elmer D. Nash 2,730,361 1/19 56 Kerr 271/45 3,309,078 3/1967 Nash 271/50 X 3,310,169 3/1967 Forrester 271/74 X Primary Examiner.loseph Wegbreit Assistant Examiner-Bruce H. Stoner, Jr. Attorney-Yount and Tarolli ABSTRACT: The present sheet-feeding apparatus has a plurality of spaced-apart transfer belts through which vacuum is applied to the underside of a sheet to enable the transfer belts to move the sheet into a printing press or other machine. A plurality of fingers press the sheet toward the transfer belts to facilitate the application of vacuum to the sheet. In addition, high-velocity jets of air may be directed along the underside of the sheet, alone or in conjunction with the fingers, to form areas of low pressure to enable immediate firm gripping of sheets, thereby resulting in higher speed operation and production of the machine.

PATENTED SEP1 4 I971 SHEET 1 (IF 5 ATENTEU SEP1 4 |97l SHEET 2 OF 5 m OE PATENTED SEP1 4 I9?! SHEET 3 OF 5 INVENTOR. EZMEE 0. A/A-SH ATTORNEYS mimiusammn 3.5041703 SHEET & 0F 5 INVENTOR. ELMER Q NASH M I ATTORNEYS SHEET-FEEDING APPARATUS This invention relates to a sheet-feeding apparatus having an improved transfer mechanism for transferring the sheet to a sheet-handling machine, such as a rotary printing press, after the sheet has been registered against front stops in the feeding apparatus.

In U.S. Pat. application Ser. No. 727,770 filed May 9, 1968 by C. M. Carey, now U.S. Pat. No. 3,542,360 there is disclosed a sheet-feeding apparatus for use with a rotary sheetfed printing press. In that apparatus the sheets are advanced successively in underlapped relationship by a conveyor against front stops, which register the leading edge of the lead sheet, after which the front stops are retracted and the lead sheet is rapidly forwarded by transfer belts to a press cylinder while the conveyor continues to advance the following sheets. The sheet being transferred is held against the transfer belts by vacuum which is applied to the underside of the sheet through the transfer belts. In order to efficiently apply vacuum to the underside of the sheet, it is necessary for the sheet to be disposed in engagement with the transfer belts. Difficulty has heretofore been experienced in applying vacuum to the underside of the sheet due to space between the sheet and the transfer belts. This difficulty has been particularly acute when heavy, wavy stock is being fed to the printing press.

The present invention is directed to a transfer mechanism in a sheet-feeding apparatus which includes new and improved means for urging the sheet into engagement with sheet-feeding means through which vacuum is applied to the underside of the sheet.

Another object of this invention is to provide a new and improved sheet-feeding apparatus including nozzle means for directing jets of air to urge the sheet into engagement with sheet-feeding means which is operated contemporaneously therewith to apply vacuum to the underside of the sheet and move the sheet toward a machine for working on the sheet.

Another object of this invention is to provide a new and improved sheet-feeding apparatus including a plurality of fingers which are movable to and from an operating position in which they press the underside of a sheet into engagement with sheet-feeding means which is operated contemporaneously therewith to apply vacuum to the underside of the sheet and move the sheet toward a machine for working on the sheet.

Another object of this invention is to provide a new and improved sheet-feeding apparatus which includes a plurality of transfer belts and suction means for applying vacuum to the underside of a sheet through the transfer belts to enable the sheet to be moved forwardly by the transfer belts and wherein the application of vacuum to the underside of the sheet is facilitated by moving a plurality of fingers from an operating position in which they are spaced apart from the sheet to an operating position in which they press the sheet against the belts contemporaneously with initiation of operation of the suction means.

Another object of this invention is to provide a new and improved sheet-feeding apparatus in accordance with the nextpreceding object and wherein nozzle means is provided for directing jets of air adjacent to the underside of the sheet contemporaneously with the aforesaid initiation of operation of the suction means and movement of the fingers to the operated position.

Another object of this invention is to provide a new and improved sheet-feeding apparatus which includes a plurality of transfer belts and suction means for applying vacuum to the underside of a sheet to enable it to be moved forwardly by the transfer belts and wherein the application of vacuum to the underside of the sheet is facilitated by directing jets of air adjacent to the underside of the sheet contemporaneously with initiation of operation of the suction means.

Further objects and advantages of this invention will be apparent from the following description of a presently preferred embodiment, which is illustrated in the accompanying drawings in which:

FIG. 1 is a top perspective view, with parts broken away for clarity, showing a sheet-feeding apparatus illustrating the present invention;

FIG. 2 is a plan view of the sheet-feeding apparatus of FIG. 1 illustrating the relationship between a plurality of transfer belts through which vacuum is applied to the underside of a sheet and finger members and nozzles for urging the sheet into engagement with the transfer belts;

FIG. 3 is an enlarged fragmentary view, partly in side elevation and partly in section, showing the feeding apparatus of FIG. 1 just before it transfers the lead sheet onto a cylinder of a printing press;

FIG. 4 is a view similar to FIG. 3 illustrating the feeding apparatus after the sheet has been partially transferred onto the press cylinder;

FIG. 5 is a side elevational view of a drive mechanism for moving the finger members between a plurality of operating positions; and

FIG. 6 is a timing chart showing the timing of certain operations in the sheet-feeding apparatus for FIG. I.

The present invention provides a new and improved mechanism for feeding sheets or sheetlike articles to a machine for working on them, such as a printing press or cutter and creaser. The feeding mechanism includes a plurality of transfer belts through which vacuum or suction is applied to the underside of each of the sheets in turn. Once a sheet has been pressed tightly against the transfer belts by the application of vacuum or suction to the underside of the sheet, the transfer belts are moved forwardly to advance the sheet into the machine. To promote the efficient application of vacuum or suction to the underside of the sheet, finger members are moved to an operating position in which they press the sheet against the transfer belts contemporaneously with initiation of the application of vacuum to the underside of the sheet. In addition, air jets can be used separately or in combination with the fingers to urge the sheet against the transfer belts. In the illustrated embodiment of the invention, the air jets are directed along the underside of the sheet to for in areas of relatively low pressure contemporaneously with movement of the fingers to the aforesaid operated position.

Referring to FIG. 1, the sheet-feeding apparatus in which the present invention is embodied includes a conveyor 10 of known design for advancing sheets or sheetlike articles 12 individually in succession from a stack or pile 14. The conveyor includes a plurality of laterally spaced endless feed tapes 16 which advance the sheets from left to right in FIG. 1. The sheets 12 are picked up individually from the pile 14 by conventional suckers (not shown) and transferred onto the feed tapes 16 beneath overlying pull-in wheels 18. The feed tapes 16 are continuously driven across a tape table 20, which is inclined downward to the right at a slight angle. The sheets 12 are held down against the feed tapes 16 by a plurality of rollers 22, which bear down on the sheets with sufficient force to maintain each sheet in frictional engagement with the feed tapes. Preferably, the sheets 12 are underlapped with the trailing end of the preceding sheet overlying the leading end of the immediately following sheet as they are advanced by the conveyor 10.

The feed tapes l6 discharge the successive sheets onto a register plate 26 which extends downward to the right from the front ends of the feed tapes at the same angle of inclination as the tape table 20. A plurality of laterally spaced front stops 30 are provided for engaging and registering the leading edge of each sheet as it passes over the register plate 26 and before it is transferred onto a cylinder 32 of a printing press by the transfer mechanism of the present invention.

Each of these front stops 30 is constituted by a depending lip 36 on the lower end of a respective lever arm 38, which is clamped to a rocker shaft 42 extending laterally across the register plate 26 at a location above the latter. In the particular embodiment shown the front stops 30 and rocker shaft 42 are located above the register plate 26, although it will be understood that the front stops and rocker shaft could be located below the register plate if desired.

At one point in each cycle of operation of this sheet-feeding apparatus, shaft 42 is turned counterclockwise, as viewed in FIG. 1, to lift the front stops 30 up out of the path of movement of the oncoming sheet 12. At another point in each cycle of operation, shaft 42 is turned clockwise to lower the stops down into the path of the next-succeeding oncoming sheet.

The register plate 26 has openings 46 for receiving the lips 36 of the respective front stops 30 when the respective lever arms 38 are in their lowered positions, as shown in FIGS. 1 and 3. In these positions, the front stops are in the path of the front or leading edge 48 of the sheet 12a (FIG. 3) which is moving across the register plate 26 from left to right. The front stops 30 are in precise alignment with each other laterally across the register plate 26 so that, when engaged by the leading edge of the oncoming sheet, they align this edge in precise parallelism with the axis of rotation of the press cylinder 32 onto which the sheet is to be fed.

-When shaft 42 is turned to raise the front stops 30 (FIG. 4), the front stops move up out of the path of the sheet 12a which had just been registered against these front stops, permitting this sheet to be transferred onto the press cylinder by the transfer mechanism 54 of the present invention, to be described.

The sheet-feeding equipment also includes a side register mechanism 56 (FIG. 1) of known design. This side register mechanism operates automatically to position each sheet at the correct position laterally before it is transferred onto the press cylinder 32. This side registration of the sheet takes place after its leading edge has been front registered by the front stops 30.

A plurality of laterally spaced, movable fingers or members 60, (see FIGS. 1, 2 and 3), overlie the sheet as it passes over the register plate 26. These fingers 60 are attached to a rocker shaft 62 extending laterally above the tape table 20. The rocker shaft 62 is turned by a drive mechanism 66 (FIGS. 2 and at predetermined times during each cycle of operation to move the fingers 60 between an intermediate position 70 (see FIGS. 3, 4, and 5), a lowered position 72, and a raised position 74. In the intermediate position 70 the fingers 60 are above the register plate 26 and transfer mechanism 54 so that they guide the sheet 12a into engagement with the front stops 30. After the sheet 12a has been registered relative to the cylinder 32 by leading edge engagement with the front stops 30, the fingers 60 are moved to the lowered position 72 by operation of the drive mechanism 66 (FIG. 5). Finally the fingers 60 are moved to the raised position 74 by the drive mechanism 66 to enable the sheet to be readily advanced onto the cylinder 32 by operation of the transfer mechanism 54.

The press cylinder 32 is rotatable at the front end of the register plate 26 of the sheet-feeding apparatus. This cylinder carries a plurality of gage pins or stop pins 80 (FIGS. 1 and 4) for engagement by the leading edge of the sheet which is then being transferred onto the cylinder 32. These stop pins 80 are in precise alignment with each other across the cylinder 32 along a line extending parallel to the cylinders rotational axis and parallel to the front stops 30.

The press cylinder32 also has a plurality of grippers 82 of known design which are all mounted on a cross-shaft 84 carried by the cylinder.

Just before the advancing sheet moves against the front stops 30, it passes over a plurality of transfer belts 88 in the present transfer mechanism. These belts are located at respective laterally spaced, rectangular openings 90 in the register plate 26 (FIG. 2). Each of the transfer belts 88 has its opposite ends secured to a respective rotatable drive pulley 92 (FIGS. 3 and 4) which is turned back and forth in opposite directions in timed relationship with the advance of each sheet against the front stops 30 and with the rotation of the press cylinder 32.

Each transfer belt 88 passes up from one side of the drive pulley 92 over a rear guide in the form of an idler roller 94, which is located near the rear edge of the respective opening 90 in the register plate 26. From this rear idler roller 94 a straight or flat upper rim portion 95 of the transfer belt passes through the opening 90 at a level slightly above the upper surface 96 of the register plate 26. The transfer belt 88 then passes around a front guide in the form of an idler roller 98, which is located near the front edge of the opening 90. The transfer belt passes down around this front idler roller 98 and over the opposite side of the drive pulley 92 to its point of attachment to the drive pulley.

Between its rear guide roller 94 and the front guide roller 98 the upper rim portion 95 of each transfer belt 88 passes over a respective vacuum table 102, which is located at the respective opening in the register plate 26. As shown in FIGS. 3 and 4, this vacuum table has a recess 104 at the top across which the respective transfer belt 88 passes. This recess 104 in each vacuum table is connected through a timing valve 106 to a source of vacuum. The portion of the transfer belt 88 which passes over this recess 104 has a plurality of openings 108 which enable the vacuum in the recess or chamber 104 to be applied to the underside of the sheet 12a which then overlies this portion of the belt.

FIG. 3 shows the position of the drive pulley 92 and the transfer belt 88 just after the sheet 12a has moved into registration with the front stops 30 and side registration of the sheet by the side registration mechanism 56 has been initiated. The drive pulley 92 is in its extreme counterclockwise position at this time. Shortly before the stop pins 80 on the press cylinder 32 have moved up past the front edge of the register plate 26, jets or high-speed streams of air are directed forwardly along the underside of the sheet 12a by laterally spaced nozzles 110 (see FIGS. 2 and 3). The jets of air flow between the underside of the sheet 12a and upper surface 96 of the register plate 26 in areas or passages 114 (FIG. 5) between the straight upper run portions of the transfer belts 88. Since the transfer belts 88 support the sheet 12a with only a small clearance between the sheet and surface 96 of the register plate 26, the passages 114 are relatively thin or shallow so that the jets of air from the nozzles move through the passages at a relatively high speed without an increase in the thickness of the jets of air. The high-speed flow of air through the thin or shallow passages 114 tends to reduce the pressure on the underside of the sheet 12a so that it is urged downwardly against the transfer belts 88 by the comparatively high pressure on the upper side of the sheet. In one exemplary embodiment of the invention, the upper surfaces of the belts 88 were raised above the surface 96 to form passages 114 with a thickness of 0.020 of an inch. Of course, passages 1 14 of other thicknesses can be formed by merely varying the extent to which the belts 88 project above the surface 96 or by forming recesses in the register plate 26.

A timing valve 116 is provided for controlling the flow of air to the nozzles 110 and the vacuum tables 102. The timing valve 116 is actuated by the press drive in timed relationship with the rotation of the press cylinder 32, operation of the finger drive mechanism 66, and the operation of the valve 106. This timed relationship is such that the fingers 60 are operated from their intermediate position 70 to their lower position 72 (FIG. 3) after the high-speed streams or jets of air begin to flow from the nozzles I10. The sheet 12a is then urged firmly downwardly against the transfer belts 88 by the combined effect of the jets of air and the fingers 60.

Immediately after the fingers 60 are moved to their lower position, the valve I06 is operated to initiate the application of suction or vacuum to the underside of the sheet 12a. Since the sheet 12a is urged into engagement with the transfer belts 88 by the combined effect of the fingers 60 and the jets of air from the nozzles 110, there is little if any space between the underside of the sheet 12a and the upper surfaces of the transfer belts 88. Therefore, vacuum can be quickly applied to the underside of the sheet 12a through the openings 108 in the transfer belts 88 upon operation of the valve 106. This is important since the sheets 12 are fed in rapid succession to the press cylinder 32 by the transfer mechanism 54.

Although the fingers 60 and nozzles 110 have been described herein as providing for a combined downward urging of the sheet 120, it is contemplated that they could be used separately. In addition, the jets of air from the nozzles 110 could be left on continuously rather than being interrupted as in the illustrated embodiment of the invention.

After the sheet 120 has been drawn into engagement with the belts 88 by the application of suction to the underside of the sheet, shaft 62 is turned counterclockwise in FIG. 1 to retract the retaining fingers 60 upwardly away from the sheet to the upper position 74. In this upper position sufficient clearance is provided to enable the sheet to be readily fed to the press cylinder 32. Next, the front stops 30 are retracted upward away from the leading edge 48 of the sheet 12a, and then the drive pulley 92 is rapidly turned clockwisefrom the FIG. 3 position to the FIG. 4 position by a suitable drive mechanism. This forward rotation of the drive pulleys causes the transfer belts 88 to move from left to right over the

guide rollers

94 and 98, carrying with them the sheet 12a because of the vacuum which continues to be applied to the underside of the sheet through the openings 108 in the transfer belts.

This forward movement of the transfer belts 88 is at a velocity substantially greater than the speed at which the drive tapes 16 are advancing the following sheets onto the register plate 26 and greater than the peripheral velocity of the press cylinder 32. Consequently, the sheet 12a which is advanced by the belts 88 and has its leading edge 48 forced into engagement with the stop pins 80 on the rotating press cylinder 32, after which the grippers 82 grip it securely against the press cylinder in the usual manner. The stop pins 80 register the leading edge 48 of the transferred sheet on the press cylinder. As shown in FIG. 4, the fingers 60 when in the upper or raised position 74 are retracted far enough up away from the sheet 12a to avoid marking the sheet if it bows upwardly after its leading edge first engages the stop pins 80 on the press cylinder 32 and while its training end continues to be advanced by the belts 88 at a speed greater than the peripheral velocity of the press cylinder.

After the grippers 82 on the press cylinder 16 have gripped the sheet, the timing valve 106 is operated to disconnect the source of vacuum from the recess 104 in the vacuum tables 102. Immediately after the vacuum is disconnected, the valve 116 connects the vacuum tables 102 to a pressurized air source so that the trailing end of the sheet 12a is released from the transfer belts 88.

After the trailing edge of this sheet has moved past the front stops 30, the rocker shaft 42 is turned clockwise in FIG. 1 to lower the front stops 30 into the respective openings 46 in the register plate 26, so as to be positioned for engagement by the leading edge of the next sheet 12b (FIG. 3) in the series which is being moved forward continuously by the feed tapes 16. At the same time, the shaft 62 is pivoted clockwise in FIG. 1 by the drive mechanism 66 to lower the fingers 60 to the intermediate position 70 for guiding the oncoming sheet 12!: on the register plate 26 without, however, exerting any significant pressure on this sheet as long as it engages the register plate.

While the oncoming sheet 12b is moved across the register plate 26 and over the transfer belts 88 at the openings 90 in the register plate, air pressure is applied to each vacuum table recess 104 through the valve 116 to provide a thin film of air for keeping the underside of the sheet separated from the corresponding transfer belt 88. At this time, the transfer belts are being retracted from right to left between the front guide roller 98 and the rear guide roller 94 by the rotation of the drive pulleys 92 counterclockwise from the FIG. 3 position. The drive pulleys reach their extreme counterclockwise position, shown in FIG. 3, before the leading edge of the oncoming sheet 12b has reached the front stops 30. Since the drive mechanism 54 is fully described in the aforementioned application Ser. No. 727,770 filed May 9, 1968 by C. M. Carey, the drive mechanism will not be further described herein.

Referring to FIG. 6, the timing of the different operations of this sheet-feeding apparatus takes place as follows, with reference to the rotation of the press cylinder 32, whose 0 position is where the stop pins 80 are aligned with the register plate 26.

The front stops 30 begin to move down at about 200 and they are in their sheet-registering position at about 240. The fingers 60 also begin to move down from the upper position 74 at about 200. The fingers 60 reach the intermediate position 70 at about 240 and remain there to guide the sheet 120 into engagement with the front stops 30. The leading edge 48 of the lead sheet 12a reaches the front stops at about 250.

After the front stops 30 reach their sheet-registering position, jets of air begin to flow out of the nozzles at about 260. The fingers 60 begin to move to the lower position 72 (FIG. 3) from the intermediate position 70 at about 310 and reach the lower position at about 319. The sheet 12a is then pressed against the transfer belts 88 under the combined effect of the fingers 60 and the jets of air from the nozzles 110.

The side register device 56 accomplishes the side registration of the sheet during the interval from about 280 to 319 and this registration is maintained by continuous operation of the side register device until about 330.

The application of vacuum to the transfer belts 88 is initiated at about 319. Since the sheet is pressed against the transfer belts by the combined effect of the fingers 60 and jets of air from the nozzles 110, vacuum is readily applied to the underside of the sheet 12a. The fingers 60 then begin to move toward the upper position 74 at about 327. Immediately thereafter, the air jets from the nozzles 110 are terminated.

The transfer belts 88 begin their forward stroke at about 330. This forward stroke of the transfer belts continues until about 30, but the release of the vacuum on the transfer belts begins at 10 and is completed by 15 to permit the sheet to be readily transferred onto the press cylinder 32. Air pressure is applied to the vacuum table recesses 104 through the valve 116 at the same time that the vacuum is released.

The transfer belts remain in their forward positions from 30 to 40. At 40 the transfer belts drive mechanism begins to retract the transfer belts 88. This retraction of the transfer belts takes place from 40 to 110, and the vacuum table recesses 104 are subjected to air pressure all this time. This results in the formation of a thin film of air which facilitates movement of the next-succeeding sheet into engagement with the front stops 30.

The drive mechanism 66 for the fingers 60 includes a cam which is mounted for rotation on a shaft 152 in a timed relationship with the cylinder 32. A pushrod assembly 156 operatively connects the cam 150 with the shaft 62 so that upon rotation of the cam 150, shaft 62 is rocked or pivoted to move the fingers 60 between the lower position 72, the upper or raised position 74 and the intermediate position 70. Accordingly, the pushrod assembly 156 includes a follower disk 160 which is rotatably mounted on a rocker arm 162 which pivots about a shaft 164. Rotation of the cam 150 moves the follower disk 160 from the position illustrated in solid lines in FIG. 5 in which the fingers 60 are in the lower position 72 to the position illustrated in dashed lines in FIG. 5 in which the fingers 60 are moved to the upper position 74.

This motion of the follower disk 160 is transmitted to the fingers 60 by the pushrod assembly 156 and an actuator lever 168 which is fixedly connected to the shaft 62. The assembly 156 includes a pushrod 170 which is pivotally connected at its lower end to the rocker arm 162. The pushrod 170 is movable relative to the actuator lever 168 to enable sheets of different thicknesses to be positioned between the transfer belts 88 and the fingers 60. To this end the pushrod 170 is slidable axially relative to the actuator lever 168 against the influence of a biasing spring 174 which engages a reaction block 176 at one end and presses at the other end against a slidable connection 178 to the actuator lever 168. Thus, when relatively thin stock is being fed to the cylinder 32, the fingers 60 are pressed downwardly against the relatively thin sheets by the action of the spring 174. Similarly, when relatively thick sheets are being fed to the cylinder 32, the fingers 60 are movable upwardly against the influence of the spring 174 when the fingers When sheets of different thicknesses are being fed to the cylinder 32, it is often desirable to be able to vary the spacing between the fingers 60 and the transfer belt 88 when the fingers are in the

operating position

70, 72 or 74. This is accomplished by rotating an adjusting knob 182 to vary the position of the sliding connection 178 relative to the reaction block 176. Of course, the axial movement of the adjusting knob 182 will vary the position or spacing of the fingers 60 from the transfer belts when the fingers are in each of the operating positions 70, 72 and 74.

During operation of the transfer apparatus 54, the cam 150 is rotated in a counterclockwise direction, as indicated by the arrow 188 in FIG. 5. On rotation of the cam 150 from the position shown in FIG. in which the fingers 60 are in the lower position 72, the follower disk 160 moves along a ramp 190 through an arcuate distance indicated at 192 to move the fingers 60 from the lower position 72 to the upper position 74.

' The fingers 60 are maintained in the upper position while the roller disk 160 moves along the dwell surface 194 through the relatively large arcuate distance 196. Continued rotation of the cam 150 moves a down ramp 200 to a position adjacent to the follower disk 160. Once the cam 150 has been rotated through an arcuate distance indicated at 202, the follower disk engages a dwell portion 204 and the fingers 60 remain in the intermediate position 70 while the cam is moved through an arcuate distance indicated at 206 in FIG. 5. The follower disk 160 then moves into engagement with another down ramp 210 while the cam 150 moves through an arcuate distance indicated at 212 in FIG. 5. Finally, the follower disk again engages a dwell surface 214 and the fingers 60 remain in the lower position 72 while the cam 150 is moved through the relatively small arcuate distance indicated at 216 in FIG. 5.

' in view of the foregoing description it can be seen that the sheets 12 are registered relative to the cylinder 32 by engagement with the front stops 30 is guided by the fingers 60 which are maintained in the intermediate position 70 as the sheets move into engagement with the front stops. This movement of the sheets is promoted by supplying air under pressure to the recess or chamber 104 in the vacuum table 102. Immediately after the sheet 12a engages the front stops 30, the sheet 12a is also urged into engagement with the transfer belts 88 by jets of air, directed adjacent to the underside of the sheets by nozzles 110. The high-speed movement of the air from the nozzles 110 creates a low-pressure area adjacent to the undersurface of the sheet 12a so that the relatively high atmospheric pressure on the upper surface of the sheet presses the sheet downwardly. The sheet is also pressed against the transfer belts 88 by movement of the fingers 60 to the lower position 72.

Immediately after the fingers 60 have been moved to the lower position and a flow of air initiated from the nozzles 110, the valve 106 is operated to connect the recess or chamber 104 in fluid communication with a source of suction or vacuum. This vacuum is then applied to the underside of the sheet 12a through openings 108 in the transfer belts 88. The application of vacuum to the underside of the sheet 120 is facilitated by the fact that the sheet has previously been urged into engagement with the transfer belts 88 under the influence of the fingers 60 and the jets of air from the nozzles 110. While the fingers60 are not moved to the lower position 72 nor the air jets turned on simultaneously with the application of vacuum to the chamber 104, these events occur during a relatively short time period and are therefore considered to occur contemporaneously with each other. It should be noted that while in the preferred embodiment the flow of air form the nozzles 110 is intermittent, it has been found that under certain conditions the air jets can be left on continuously.

Having described my invention, 1 claim:

1. Apparatus for feeding sheetlike articles to a machine for working thereon, said apparatus comprising means for arresting and registering leadingedge portions of the sheetlike articles relative to said machine, conveyor means for moving the leading edge portions of each of the sheetlike articles in turn into engagement with said registering means to effect leading edge registration of the sheetlike articles, belt means for gripping and moving the sheetlike articles toward said machine after registration, first means selectively operable for applying vacuum through at least a portion of said belt means to the underside of the sheetlike article overlying said portion of said belt means to thereby urge the underside of the sheetlike article into engagement with said belt means, second means for further urging the underside of the sheetlike article into engagement with said belt means, said belt means including a plurality of transfer belts spaced apart from each other in a direction transverse to the direction of movement of the sheetlike articles, said apparatus further including plate means extending between said transfer belts, said plate means having upper surface areas between said transfer belts and below the upper surfaces of said transfer belts to thereby form a plurality of relatively wide thin passages between said upper surface areas of said plate means and the underside of the sheetlike article, and said second means including a plurality of spacedapart nozzle means for directing jets of air through said passages between the upper surfaces of said plate means and the underside of the sheetlike article to thereby tend to form areas of relatively low pressure between said transfer belts and adjacent to the underside of the sheetlike article, and control means for effecting operation of said first means to apply vacuum through said transfer belts to the underside of the sheetlike article while jets of air are flowing from said plurality of spaced-apart nozzle means through said wide thin passages to thereby urge the underside of the sheetlike article into engagement with said belt means under the combined influence of the vacuum and the areas of low pressure formed by the jets of air.

2. Apparatus as set forth in claim 1 wherein said second means further includes means for applying pressure against the upper side of the sheetlike articles.

3. Apparatus as set forth in claim 2 wherein said means for applying pressure to the upper side of the sheetlike articles includes a plurality of finger members and said control means includes actuator means for moving said finger members between a first position in which said finger members are spaced from the upper side of the sheetlike article to enable the sheetlike article to be readily moved into said machine once it engages the sheetlike article and a second position in which said finger members engage the upper side of the sheetlike article to press its underside toward said belt means.

4. Apparatus as set forth in claim 1 wherein said control means includes valve means connected in fluid communication with said nozzle means and with a source of air under pressure, said valve means being operable to direct air under pressure to said nozzle means during the application of vacuum to the underside of the sheetlike article by said first means, said valve means also being operable to direct a flow of air to said first means after a sheetlike article has been transferred to said machine to thereby facilitate disengagement of the sheetlike article from said belt means and movement of the leading edge of a-next-succeeding sheetlike article into engagement with said registering means.

5. Apparatus for feeding sheetlike articles to a machine for working thereon, said apparatus comprising means for arresting and registering leading edge portions of the sheetlike articles relative to said machine, conveyor means for moving the leading edge portions of each of the sheetlike articles in turn into engagement with said registering means to effect leading edge registration of the sheetlike articles, belt means for gripping and moving the sheetlike article toward said machine after registration, first means selectively operable for applying vacuum through at least a portion of said belt means to the underside of the sheetlike article overlying said portion of said belt means to thereby urge the underside of the sheetlike article into engagement with said belt means, second means disposed above said belt means for applying a downwardly directed pressure against the upper side of the sheetlike article at a location overlying said belt means to press the underside of the sheetlike article into engagement with said belt means,

and control means for operating said first means to apply vacuum to the underside of the sheet contemporaneously with the application of pressure against the upper side of the sheetlike article by said second means to thereby urge the underside of the sheetlike article into engagement with said belt means under the combined influence of said first and second means.

6. Apparatus for feeding sheetlike articles to a machine for working thereon, said apparatus comprising means for arresting and registering leading edge portions of the sheetlike articles relative to said machine, conveyor means for moving the leading edge portions of each of the sheetlike articles in turn into engagement with said registering means to effect leading edge registration of the sheetlike articles, belt means for gripping and moving the sheetlike articles toward said machine after registration, first means selectively operable for applying vacuum through at least a portion of said belt means to the underside of the sheetlike article overlying said portion of said belt means to thereby urge the underside of the sheetlike article into engagement with said belt means, second means for further urging the underside of the sheetlike article into engagement with said belt means, said second means including means for applying pressure against the upper side of the sheetlike article to press the sheetlike article downwardly toward said belt means and a plurality of spaced-apart nozzle means for directing jets of air adjacent to the underside of the sheetlike article to thereby form a plurality of areas of relatively low pressure adjacent to the underside of the sheetlike article, and means for operating said second means to press the sheetlike article downwardly and to form the areas of low pressure adjacent to the underside of the sheetlike article while said first means applies vacuum to the underside of the sheetlike article to thereby urge the underside of the sheetlike article into engagement with said belt means under the combined influence of said first and second means.

7. Apparatus for feeding sheetlike articles to a machine for working thereon, said apparatus comprising means for registering leading edge portions of the sheetlike articles relative to said machine, conveyor means for moving the leading edge portions of each of the sheetlike articles in turn into engagement with said registering means to effect leading edge registration of the sheetlike articles, infeed means for moving the sheetlike articles toward said machine after registration, said infeed means including selectively operable means for applying vacuum to the underside of a sheetlike article and moving the sheetlike article toward said machine, a plurality of finger members selectively movable between a plurality of operating positions, said finger members being operable to a first position in which they are spaced a first distance above said infeed means in an orientation to enable said finger members to guide the sheetlike articles into engagement with said registering means, said finger members being operable to a second position in which they engage an upper side of a sheetlike article overlying said infeed means and press the sheetlike article into engagement with said infeed means to facilitate the application of vacuum to the underside of the sheetlike article by said infeed means, and said finger members being operable to a third position in which they are spaced from said infeed means by a second distance which is greater than said first distance to facilitate transferring of the sheetlike article to said machine after the application of vacuum to the underside of the sheetlike article by said infeed means, and control means for regulating the operation of said infeed means and finger members in such a manner that said finger members are moved to said second operating position contemporaneously with initiation of operation of said infeed means to apply vacuum to the underside of the sheetlike article.

8. Apparatus as set forth in claim 7 further including resilient means for pressing said finger members against the upper side of the sheetlike article when said finger members are in said second operating position.

9. Apparatus as set forth in claim 7 wherein said infeed means includes a plurality of spaced-apart transfer belts, said finger members in said second operating position being located directly opposite said belts.

10. Apparatus as set forth in claim 7 further including nozzle means for directing jets of air adjacent to the underside of the sheetlike article contemporaneously with the operation of said fingers to their second operating position and the initiation of the operation of said infeed means to apply vacuum to the sheetlike article.

11. Apparatus as set forth in claim 10 wherein said infeed means includes a plurality of spaced-apart transfer belts through which vacuum is applied to the underside of the sheetlike article by said infeed means, said nozzle means being positioned to direct the jets of air through the spaces between the transfer belts in the direction of movement of the sheetlike articles.

12. Apparatus as set forth in claim 7 further including nozzle means for directing jets of air adjacent to the underside of the sheetlike article, said control means being operable to initiate a flow of air from said nozzle means contemporaneously with movement of said finger members to said second position and the initiation of the operation of said infeed means to apply vacuum to the underside of the sheetlike article.

13. Apparatus as set forth in claim 12 wherein said control means is operable to effect movement of said finger members to their third operating position and to terminate the flow of air from said nozzle means before the application of vacuum to the underside of the sheetlike article is terminated to thereby further facilitate movement of the sheetlike article toward said machine by said infeed means.

14. Apparatus for feeding sheetlike articles to a machine for working thereon, said apparatus comprising means for arresting and registering leading edge portions of the sheetlike articles relative to said machine, conveyor means for moving the leading edge portions of each of the sheetlike articles in turn into engagement with said registering means to effect leading edge registration of the sheetlike articles, belt means for gripping and moving the sheetlike articles toward said machine after registration, first means selectively operable for applying vacuum through at least a portion of said belt means to the underside of the sheetlike article overlying said portion of said belt means to thereby urge the underside of the sheetlike article into engagement with said belt means, second means for further urging the underside of the sheetlike article into engagement with said belt means, said second means including means for applying pressure against the upper side of the sheetlike articles, and control means for operating said second means contemporaneously with initiation of operation of said first means to thereby urge the underside of the sheetlike article into engagement with said belt means under the combined influence of said first and second means, said means for applying pressure to the upper side of the sheetlike article includes a plurality of finger members and said control means includes actuator means for moving said finger members between a plurality of operating positions, said finger members in a first operating position being spaced a first distance from said belt means to enable the sheetlike article to be readily transferred to said machine, said finger members in a second operating position being spaced from said belt means by a second distance which is smaller than said first distance to enable said finger members to guide the sheetlike article into engagement with said registering means, said finger members in a third operating position being in engagement with the upper side of the sheetlike article to press the sheetlike article into engagement with said belt means, and wherein a surface is provided slightly below the outer surface of the portion of said belt means through which vacuum is applied to the underside to the sheetlike article and said second means further includes means for directing streams of air adjacent to the underside of the sheetlike article at locations intermediate said finger members when said finger members are in said third position, said airstreams being directed substantially parallel to said surface in the direction of sheet feed.

15. Apparatus for feeding sheetlike articles to a machine for working thereon, said apparatus comprising means for arresting and registering leading edge portions of the sheetlike articles relative to said machine, conveyor means for moving the leading edge portions of each of the sheetlike articles in turn into engagement with said registering means to effect leading edge registration of the sheetlike articles, belt means for gripping and moving the sheetlike articles toward said machine after registration, first means selectively operable for applying vacuum through at least a portion of said belt means to the underside of the sheetlike article overlying said portion of said belt means to thereby urge the underside of the sheetlike article into engagement with said belt means, second means for further urging the underside of the sheetlike article into engagement with said belt means, and control means for operating said second means contemporaneously with initiation of operation of said first means to thereby urge the underside of the sheetlike article into engagement with said belt means under the combined influence of said first and second means, said second means includes a plurality of finger members and said control means includes actuator means for moving said finger members between a plurality of operating positions, said finger members in a first operating position being spaced a first distance from said belt means to enable the sheetlike article to be readily transferred to said machine, said finger members in a second operating position being spaced from said belt means by a second distance which is smaller than said first distance to enable said finger members to guide the sheetlike article into engagement with said registering means, said finger members in a third operating position being in engagement with the upper side of the sheetlike article to press the sheetlike article into engagement with said belt means.

Claims

1. Apparatus for feeding sheetlike articles to a machine for working thereon, said apparatus comprising means for arresting and registering leading edge portions of the sheetlike articles relative to said machine, conveyor means for moving the leading edge portions of each of the sheetlike articles in turn into engagement with said registering means to effect leading edge registration of the sheetlike articles, belt means For gripping and moving the sheetlike articles toward said machine after registration, first means selectively operable for applying vacuum through at least a portion of said belt means to the underside of the sheetlike article overlying said portion of said belt means to thereby urge the underside of the sheetlike article into engagement with said belt means, second means for further urging the underside of the sheetlike article into engagement with said belt means, said belt means including a plurality of transfer belts spaced apart from each other in a direction transverse to the direction of movement of the sheetlike articles, said apparatus further including plate means extending between said transfer belts, said plate means having upper surface areas between said transfer belts and below the upper surfaces of said transfer belts to thereby form a plurality of relatively wide thin passages between said upper surface areas of said plate means and the underside of the sheetlike article, and said second means including a plurality of spaced-apart nozzle means for directing jets of air through said passages between the upper surfaces of said plate means and the underside of the sheetlike article to thereby tend to form areas of relatively low pressure between said transfer belts and adjacent to the underside of the sheetlike article, and control means for effecting operation of said first means to apply vacuum through said transfer belts to the underside of the sheetlike article while jets of air are flowing from said plurality of spaced-apart nozzle means through said wide thin passages to thereby urge the underside of the sheetlike article into engagement with said belt means under the combined influence of the vacuum and the areas of low pressure formed by the jets of air.

4. Apparatus as set forth in claim 1 wherein said control means includes valve means connected in fluid communication with said nozzle means and with a source of air under pressure, said valve means being operable to direct air under pressure to said nozzle means during the application of vacuum to the underside of the sheetlike article by said first means, said valve means also being operable to direct a flow of air to said first means after a sheetlike article has been transferred to said machine to thereby facilitate disengagement of the sheetlike article from said belt means and movement of the leading edge of a next-succeeding sheetlike article into engagement with said registering means.

5. Apparatus for feeding sheetlike articles to a machine for working thereon, said apparatus comprising means for arresting and registering leading edge portions of the sheetlike articles relative to said machine, conveyor means for moving the leading edge portions of each of the sheetlike articles in turn into engagement with said registering means to effect leading edge registration of the sheetlike articles, belt means for gripping and moving the sheetlike article toward said machine after registration, first means selectively operable for applying vacuum through at least a portion of said belt means to the underside of the sheetlike article overlying said portion of said belt means to thereby urge the underside of the sheetlike article into engagement With said belt means, second means disposed above said belt means for applying a downwardly directed pressure against the upper side of the sheetlike article at a location overlying said belt means to press the underside of the sheetlike article into engagement with said belt means, and control means for operating said first means to apply vacuum to the underside of the sheet contemporaneously with the application of pressure against the upper side of the sheetlike article by said second means to thereby urge the underside of the sheetlike article into engagement with said belt means under the combined influence of said first and second means.