US2819076A - Paper-handling apparatus - Google Patents

Description

P. H. WENDT ET AL PAPER-HANDLING APPARATUS Jan. 7, 1958 Filed April 29, 1955 3 Sheets-Sheet 1 how, H. (us/v07- zs/v/verx/ 2. 64025065 IN V EN TORS Jan. Y, W53 P. H. WENDT ET AL.

PAPER-HANDLING APPARATUS 3 Sheets-Sheet 2 Filed April 29, 1955 P404. AVE/V07 ZEN/V57) 8. 54026366 INVENTOR5 Jan. 7, 1958 P. H. WENDT ET AL PAPER-HANDLING APPARATUS 5 Sheets-Sheet 3 Filed April 29, 1955 1 40C H, CUE/V07 KEN/V5 7/1 2. 62.026065 IN VEN TOR5 prroe/vays United States Patent l PAPER-HANDLING APPARATUS Paul H. Wendt, Los Altos, and Kenneth R. Eldredge, Palo Alto, Calif.

Application April 29, 1955, Serial No. 504,708

9 Claims. (Cl. 271-27) This invention relates to paper-handling machinery and, more particularly, is an improved apparatus for separating single sheets from a stack.

An object of the present invention is to provide improved apparatus for separating single sheets from a stack.

A further object of the present invention is to provide apparatus which only picks up one sheet at a time.

Still another object of the present invention is to provide apparatus which can separate sheets from a stack singly and at a high speed.

The above and other features of the invention are achieved in apparatus wherein there is a shaft upon which three cylinders forming a separating drum are rotatably mounted spaced apart. In the space provided between the cylinders there is inserted a vacuum nozzle, the ends of which terminate within the periphery of the adjacent cylinders. This vacuum nozzle extends over an arc of the discs for a distance for which it is desired that the separated sheets be conveyed by the assembly. Extending from the opening of the nozzle are fingers which are arcuate to conform with the curve of the cylinders. These fingers are employed to prevent a sheet which adheres thereto, by virtue of the suction from the nozzle, from being brought in contact with the surface of the cylinders. One end of the suction nozzle is positioned adjacent the forward portion of a top sheet of a stack. The suction causes such forward portion of the top sheet to be drawn up toward the rotating cylinders. However, the fingers which extend beyond the periphery of the cylinders prevent such sheet from being moved by the rotating cylinders.

When it is desired to advance the top sheet the fingers are withdrawn into the suction nozzle. This enables the sheet to be pulled against the surface of the cylinders. The cylinder surfaces are ridged to increase the friction between the sheet and the surface. Accordingly, the sheet is moved away from the stack by the rotating cylinders to other handling apparatus which can then process it as desired. Means are provided to prevent more than one sheet from being conveyed by the drum. Further means are provided to facilitate the removal of the top sheet of the stack from the remainder of the stack.

The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention itself both as to its organization and method of operation, as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawings, in which:

Figure 1 is a plan view of the apparatus employing this invention;

Figure 2 is a side view of the drawing shown in Figure 1;

Figure 3 is a section along the line 3--3 of Figure 2 and shows details of an embodiment of the invention;

Figure 4 is a section along the line 4--4 of Figure 3 2,819,076 Patented Jan. 7, 1958 showing the placement of the vacuum nozzle between the cylinders;

Figure 5 shows the vacuum nozzles which are employed in the present invention; and

Figure 6 illustrates the apparatus employed to insure that only a single sheet is removed at a time from the stack.

Referring now to Figures 1 and 2, a stack of sheets 10 which are to be separated in a sequence of one sheet at a time are placed upward against what can be considered as a separating drum 12 which is comprised of three spaced cylinders. The stack is urged against the drum by virtue of two vibrator belts 14, 14 and a retating belt 16. A box 18 having perforations therein which open onto the top sheet of the stack 10 is ernployed to facilitate the removal of the top sheet. Compressed air is fed into the box from a source, not shown, which passes through and around the top sheet to literally float it on a cushion of air away from the sheet beneath it. A mechanism 20 is provided on one side of the sheets which prevents more than one sheet from being drawn upward by the vacuum provided by the nozzles 22 which extend into slots in the drum 12. A belt 24 passes over the removing drum and in combination with another drum 26 and belt 28 supports the top sheet of the stack which has been removed and conveys it to paper-processing apparatus 38. The drum 32 and rollers 34, 36, 33, 44 42, and 44 all serve to maintain the two belts 24 and 28 tightly pressed against one another so that the sheets are firmly held therebetween. As may be seen in Figure 2, an electric motor 46 drives the cylinders which help to maintain the belt stretched and the appara tus moving. A pressure pump 48 and a vacuum pump 50 are required and are driven from a suitable motor 52. Control apparatus 54 for varying the speed of operation to adesired value are represented by the panel and controls 54. Also shown are the stop-start buttons 5'6 for the entire apparatus.

Referring now to Figures 3 and 4, a cross section of an embodiment of the invention may be seen. A drum 12 may either be considered as being made up of three spaced apart discs or cylinders 60, 62, 64 which are mounted on a shaft 66 to be rotatable therewith or alternatively this may be considered as a cylindrical drum which has had diametrical grooves machined therein. A vacuum nozzle 22 has a double terminal portion 70, 72, each of which is inserted in the space between the cylinders 6t], 52, 64, in the manner shown in Figure 4. The vacuum is applied to the suction nozzles of the vacuum pump Sit. The terminations of the nozzle are just below the periphery of the cylinders. Accordingly, as a sheet is drawn to the drum by virtue of the suction from the nozzles, it is prevented from contacting the nozzles themselves by the periphery of the three cylinders. The openings of the nozzles extend over an are which equals the desired arc of travel of a sheet from the stack.

As may be seen in Figure 3, the vacuum nozzle is positioned with one end over the portion of the stack at which it is desired to pick up a sheet. The nozzle terminates at a point where the leading edge of the sheet has already been grasped between the two belts 28, 24'. Extending through the openings in the suction nozzle are two fingers 76, 78. These fingers are movable and are supported from push rods 80, 82. These push rods are supported in a bearing 84, 86, which extends through one side of each nozzle. The push rods each terminate in a motor member 90. The end of each push rod has a piston head 92.

In the absence of air inside the chamber 94, a spring 96 urges the fingers to extend beyond the periphery of the cylinders. This prevents the top sheet of a stack, which is caused to adhere to these fingers by reason of the suction from the nozzles, from being moved with the rotating cylinders. When it is desired to move this sheet, a solenoid 98 opens a valve 100 which permits air under pressure to enter into the chamber 94 and compress the spring 96. Thus, the plush rods 80, 82 withdraw the fingers 76, 78 into the vacuum nozzles. The top sheet of the stack is thus permitted to engage the rotating cylinders and is moved up until the leading edge is engaged engaged between the two belts. As soon as the leading edge of the sheet has been grasped by the belts the air pressure on the air motor is removed and the fingers are moved back into position to prevent a second sheet from being picked up and moved by the drum. As previously pointed out, a box 18 has air under pressure fed therein, This air is emitted through a plurality of openings in one wall of a box and serves to flow this air around the top of a top sheet and therethrough, so that it is literally floated above the sheet in the stack which is underneath. The operation of this devicehas been described in detail and claimed by Alonzo W. Noon in an application filed December 20, 1954, Ser. No. 476,444, for a Sheet-Separating Device, and assigned to this assignee.

it will be noted that one of the belts 24 fits into a groove in the middle cylinder. This is done for two reasons: first, to rotate the assembly by reason of the drive applied to the belt, and, second, to enable the removal of a sheet from the suction nozzle.

Prevention of more than one sheet being picked up at a time is insured further by the mechanism 20, which is shown in cross section in Figure 3 and in further detail in Figure 6. This consists of a box 110, which has an opening 112 in the face opposite the edges of the top sheets of the stack. Suction is applied to the box through a second opening 114. When the top sheet of a stack is drawn against the fingers and/or the drum, the sheet serves to effectively block the suction nozzle portals from which the suction is provided. The suction through the opening 112, accordingly, is free to act on any sheet which adheres or follows the top sheet. Thereby, only the top sheet is held against the separating drum. The remaining sheets are held back by suction in the stack.

It has been determined, however, that occasionally when a top sheet is being pulled up to the removing drum, a following sheet will move upward part-way and then by virtue of the suction from the opening 112 will be drawn to block such opening and will adhere to the box 110. In order to prevent the blocking and thus the disabling of the mechanism, two members 116, 118 are employed which are positioned to extend in the direction of the stack of sheets. These members are separately mounted on push rods 120, 122. Each push rod is held by means of a spring 124, so that the members 116, 118 are flat against the face of the box. When a top sheet is drawn up toward the separating drum, the solenoid 126 is operated to permit air to push against the piston head 128 to the top of the push rod 120. This serves to jog the stack of sheets away from the opening 112 a slight dis tance. Such rapid jogging prevents the following sheet from clogging the opening 112 but is not sufiicient to cause a loss of the effect of the suction through the opening 112, whereby such following sheet is prevented from also being drawn up to the separating drum.

The speed of operation of the device may be easily adjusted by controlling the speed of driving the belts from the electric motor 46. The movement of the fingers and the members for moving the top sheet and preventing the following sheets from clogging the opening 112 where desired, may be timed electronically with the speed of the operation of the apparatus. Both solenoids 98 and 126 are excited simultaneously to remove a sheet from the drum and to permit the top sheet on the stack to take its place. It should also be noted that this invention may be employed to provide a demand feed type of operation by exciting the two solenoids whenever it is desired to feed the next sheet. The length of the documents which can be handled by thismachine is limited only by the speed at which the machine runs and by the frequency at which it is desired to feed such documents or pieces of paper. For example, if the belt conveyor travels at a speed of inches per second, one sheet or document slightly less than 100 inches long or 20 documents slightly less than five inches long may be fed by the machine each second. As pointed out previously, the variations in feeding speed can be accomplished simply by varying the time intervals at which the solenoids 98 and 126 are excited.

To summarize its operation, the stack of sheets is urged against the separating drum or cylinders. The top sheet of the stack is first floated by air from the box 18 and then is sucked up against the cylinders but is held from frictional contact therewith by reason of the fingers. This blocks suction from being applied to the following sheet. The following sheet is also held 'by the suction fromthe device 20. Clogging of the device 20 at the time of pickf up of the top sheet is prevented by a slight jog received by the remaining stack from the members 116, 118. The

fingers 76, 78 are retracted into the vacuum nozzle, thus enabling the top sheet to adhere to the surface of the rotating cylinders and be moved between the two belts 24, 28 to further processing apparatus. At this time the fingers are allowed to extend from the suction nozzle again. The next sheet is then picked up. Thus, highspeed separation of a stack into single, sequential sheets can be attained. A further feature of this invention is that the succeeding sheets are not picked up at one end but rather are pulled or bent upward in a folding-unfold-.v

ing or peeling type of movement as the sheet on the drum is pulled away therefrom. This further assists the separation of the two top sheets.

There hasbeen shown and described hereinabove new, novel and useful apparatus for separating sheets singly from a stack.

We claim:

1. Apparatus for separating sheets from a stack comprising a drum having a groove, means to rotatably support said drum with its periphery in proximity to said stack of sheets, stationary suction means in and extending along a portion of said groove, a movable finger extending outward from said suction means and away from said drum surface, and means to retract said finger into said suction means to permit a sheet from said stack to be drawn against said drum surface to be movable therewith.

2. Apparatus for separating sheets from a stack comprising a drum having a circumferential groove, means to rotatably support said drum with its periphery in proximity to the top sheet of said stack of sheets, means to apply air under pressure to the top sheet of said stack of sheets adjacent one side of said drum, means to apply suction to the edges of sheets near the top of said stack which edges are extending at the other side of said drum, stationary suction means in and extending along a portion of said circumferential groove over said top sheet of said stack, a movable finger extending outward from said vacuum means and away from said drum surface, and means to retract said finger into said suction means to permit the top sheet from said stack to be drawn against said drum surface to be movable therewith.

3. Apparatus for separating sheets from a stack comprising a drum having a circumferential groove, means to rotatably support said drum with its periphery in proximity to the top sheet of said stack of sheets, means to apply air under pressure to the top sheet of said stack of sheets adjacent one side of said drum, means to apply suction to the edges of sheets near the top of said stack located furthest away from where said air under pressure is applied, stationary suction means in and extending along aportion of said circumferential groove over said top sheet of said stack, a movable finger extending outward from said stationary suction means and away from said drum surface, means to retract said finger into said suction means to permit the top sheet from said stack to be drawn against said drum surface to be movable therewith, a push rod positioned within said means to apply suction to the edges of sheets, and means to actuate said push rod to move said sheets near the top of said stack away from said means to apply suction to the edges of sheets and to be retracted while said top sheet is drawn against said drum by said stationary suction means.

4. Apparatus for separating sheets from a stack comprising a rotatably supported shaft, three cylinders mounted on said shaft spaced from one another, a pair of vacuum nozzles respectively inserted in the spaces between said cylinders, said nozzles terminating in the space between and below the peripheries of said cylinders, said nozzles extending over a desired are of carry of sheets by said apparatus, a pair of movable fingers extending through said pair of vacuum nozzles and beyond the periphery of said cylinders, and means to retract said fingers into said nozzles and within the periphery of said cylinders when it is desired to separate a sheet from a stack.

5. In apparatus as recited in claim 4 wherein each of said cylinders has axial ridging to prevent sheet slippage and the cylinder in the center has a peripheral groove to permit insertion of a conveyor belt therein.

6. In apparatus as recited in claim 4 wherein said pair of movable fingers includes a pair of arcuate members supported by a pair of rods, said pair of rods extending within said pair of vacuum nozzles.

7. In apparatus for separating sheets from a stack, a rotatably supported shaft, three cylinders mounted on said shaft spaced from one another, a pair of vacuum nozzles respectively inserted in the spaces between said cylinders, said nozzles each having an arcuate opening which is below the periphery of the cylinders and which extends over a desired arc of carry of said sheets by said apparatus, means to urge a stack of sheets toward the portion of said cylinders wherein one end of said vacuum nozzles occur to position a portion of the top sheet of said stack adjacent the arcuate opening of said nozzles, means to apply suction to the edges of said stack of sheets which are adjacent to the openings of said nozzles, means to apply air under pressure to the remaining portion of a top sheet of said stack which is not adjacent the nozzle openings, a pair of arcuate movable fingers extending through said pair of vacuum nozzles and beyond the periphery of said cylinders, and means to retract said fingers into said nozzles and Within the periphery of said cylinders when it is desired to separate a sheet from a stack.

8. In apparatus as recited in claim 7 wherein said means to apply suction to the edges of said stack includes a box having an opening through which said suction is applied, a fiat member mounted on either side of said opening, said fiat members extending in the direction. of the thickness of said stack of sheets for a plurality of sheets, and means to arcuate said flat members to deliver a push away from said box nozzle opening whenever said fingers are retracted within said nozzles.

9. In apparatus as recited in claim 7 wherein the one of the three cylinders which is in the center is grooved, a first moving conveyor belt passes into and out of said groove to rotate said three cylinders, and a second conveyor belt is positioned adjacent said first conveyor belt substantially where said suction nozzle terminates, said second conveyor belt moving in pressing contact with said first belt carrying therebetween a sheet which has been removed from the top of said stack.

References Cited in the file of this patent UNITED STATES PATENTS 1,535,215 Ehlig Apr. 28, 1925 2,125,199 Rheutan July 26, 1938 2,184,229 Spiess Dec. 19, 1939 i .-..i I W U. S. DEPARTMENT OF COMMERCE PATENT OFFICE CERTIFICATE OF CORRECTION i Patent No., 2,819,076 Paul H. Wendt et a1. January 7, 195

It is hereby certified that error appears .in the printed specification of the above numbered patent requiring correction and that the said Lettere Patent should read as corrected below.

Column 3, line 10, strike out "engaged"; line 36, after "drawn" insert -='=-up--; column 6, line 20, for "arcuate" read "actuate- Signed and sealed this 10th day of June 1958.

(SEAL) Attest:

KARL H. AXLINE ROBERT C. WATSON Attesting Officer Cannissioner of Patents

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