US2402442A - Sheet separator and method - Google Patents

Description

June 18, 1946. J. R. PERRY v SHEET SEPARATQR AND METHOD Filed March 18, 1942 INVENTOR I JOHN R. PERRY ATTORN 5Y5 Patented June 18, 1946 SHEET SEPABATOR AND METHOD John R. Perry, Pearl River, N. Y., assignor to Dexter Folder Company, Pearl River, N. Y., a corporation of New York Application March 18, 1942,. Serial No. 435,160

v y 21 Claims.

The invention relates to a device for raising the top sheet, or a portion thereof, of a pile of sheets so that secondary sheet handling means may operate or function, either to further separate the top sheet from the pile or to deliver the sheet to sheet feeding mechanism, or to perform both of these operations. The invention relates particularly to air jet and baflie means for pro- I jecting a stream of air towards the top edge of a pile of sheets and pocket the .air under at least the top sheet, so that the swirling or eddying of the air underneath the top sheet separates a por.-

tion thereof such asa corner from the .underlying sheet of the pile sumciently so that the secondary, sheet handling means may function.

It is an object of the invention to construct a. sheet separating means which utilizes an elongated jet ofair directed vertically or crosswise of the plane of the sheets and against an edge, or particularly against each edge at a corner, of the pile of sheets, and spaced at short distance therefrom, so that the air issuing from the jet or the pair of jets lifts at least the top sheet from the underlying sheet sufiiciently so that a secondary sheet handling means may operate to grip the top sheet alone, to either further separate the top sheet from the other sheets, or to deliver the top sheet to a sheet feeding means or to perform both of these operations.

Another object is to construct a sheet separating means which utilizesat least one jet of air projected cross-wise of the plane of the sheets and particularly at a short distance from the corner of the pile, and at the top of the pile, and also utilizes baiile means to pocket the air, or obstruct the escape of air from, beneath the top sheet so that Secondary sheet handling means may operate upon the top sheet alone.

Another object of the invention is to provide a new and novel method of initially separating the top heet from a pile of sheets utilizing a 'jet or jets of air and obstructing the escape of air from between the sheet.

Another object of the invention is to construct a sheet separating device which utilizes a pair of elongated jets of air to secure initial separation of a corner of a top sheet from the pile of sheets and to pocketthe air, or obstruct the escape of the air from, under the sheet so that effective initial separation of at least a portion of the top sheet, such as a corner, from the underlying sheet is obtainedwhereby a secondary sheet handling means may operate on the top sheet alone. Other. objects of the invention will be more apparent from the following description taken connection with the accompanying drawing, in

which Figure 1 is a side elevation of the sheet separating means mounted upon a sheet delivering machine and in position relatively to a pile of sheets carried upon an elevator which forms a part of the sheet feeder or sheetdellvering machine. v 1

Figure 2 is a plan view of the sheet separating devices located at each rear corner of a pile of sheets and mounted upon a sheet feeder or sheet delivering machine.

Primary sheet separating devices of various kinds are used on sheet feeders or sheet delivering machines in order toobtain positive initial separation of the corners of a sheet from the top of a pile of sheets. On .such a device, a so-called comber, is brought into contact with the corner I of the top sheet and rotation of the comber. forms a buckle in the sheet, and lesser buckle in a few of the underlying sheets, whereby initial or primary separation of the top sheet from the next or second sheet is obtained. This buckle in the top sheet provides sufficient. initial separation to enable the secondary sheet handling means to function or operate. Although such combe'rs are successful primary sheet separators, they involve considerable mechanism in order to rotate the comber and cam mechanism to bring the comber into contact with and away from contact with the top of the pile of sheets in timed relation with the other sheet handling devices upon the feeder or machine. The jet means to be described herein functions highly satisfactoril and eliminates a great deal of the mechanism which is necessary with the comber type of primary separating devices.

The sheet separating means is shown in position with respect to a pile of sheets P carried upon a board B forming the platform of an elevator for a sheet feeding machine. As the sheets are removed from the top of the pile, the elevator rises 'so that a substantially constant level is.

maintained for the top of the pile.

The sheet separator at each corner ofthe pile is preferably a single unit and comprises .an air box orchamber l0 whichis hollow so that air under pressure may be fed therethrough'. The box is'angular in construction so that one arm and particularl its inner face or wall extends along one edge of the pile of sheets and the other arm extends along the other edge. Air jet means are carriedby the box, that particularly illustrated being a thin slot ll ofabout a, of an inch wide, preferably through the wall of one arm of of air issuing from the slots. The slots provide a plurality of jets at each comer.

In the illustrated embodiment, the slot or issuing jet is as wide as the wall which is approximately an inch and one-quarter long and is 1 spaced about an inch and three quarters from the corner formed by the walls of the box, so that the slots are about an inch and a half from the corner of the pile of sheets. The jets probably fan out so that the jet at the edge of the pile is wider than at the slot. The air box with its elongated air jets is preferably positioned approximately three-eighths of an inch away from the edge of the pile of sheets. The slots and jets of air which issue therefrom extend cross-wise of the plane of the sheets and are preferably vertical with respect thereto. The air box II), as illustrated, is located in a vertical position with respect to the top of the pile of sheets such that the lower end of the jet engages a plurality of the top sheets on the pile and the level of the upper end of the jet is above the pile depending upon the extent of the separation desired. In the illustrated construction approximately A; of the jet of air extends below the top sheet and the balance of the jet is above the top sheet. The reason for this is to provide a jet of ample length for all pile situations and sheet characteristics such as when the sheets are stiff and are raised by the secondary sheet handling means, the air jet underneath the sheet isincreased as the sheet moves upwardly.

The spacing of the air box from the edges of the sheets, the velocity of the jet of air, the relative position of the jet below and above the top of the pile of sheets, and other factors are dependent largely upon the weight and character of the sheets in the pile. Heavy sheets ordinarily require a heavier blast of air than lighter sheets, which can be obtained by increasing the pressure in the air line and hence at the jets. The tendency of the sheets to stick together'is also a factor which bears upon the air blast and the loca- 'tion of the jet or jets of air and because of the great number of different kinds of sheets handled by a sheet feeder, the strength of the jets and their location for best results can be determined only by trial.

The face of each wall of the air box I which is adjacent the edges of the pile of sheets, forms a wall or baflle which obstructs or restricts the escape of air from beneath the sheets or particularly the top sheet towards the raised corner thereof. This wall assures that enough air from the jet or jets will be pocketed between the sheets so that the sheets and particularly the top sheet will balloon or fly upwardly under the combined action of the force of the jet of air and the obstruction formed by the wall, tending to prevent or resisting the escape of the air towards the corner of the sheet. The air-issuing from the two jets also engages or intermingles between the sheets to set up eddying or whirling currents of air which aid in separating particularly the top sheet from the underlying sheet in the pile. The

walls of the air box and the sheet itself form sheets.

an enclosure which obstructs the escape of air from beneath the same although if the air should, and it has been demonstrated that the air does, blowcompletely underneath the sheet that is not objectionable and in fact is ,an aid to sheet separation. The air jets also blow up at least a portion of one or more of the underlying sheets, however, the top sheet is lifted upwardly from the top of the pile and particularly is lifted or separated from the second sheet.

Supporting means are provided for the air box [0 which includes a pipe [5 carried at the corner thereof to which is connected a flexible pipe or hose, 16 which is connected in turn to a suitable source of air pressure in any suitable fashion such as through an air shaft H. The pipe l5 also serves to support the air jets or particularly, the air box with its jets and baffie wall. The pipe l5 extends vertically through another part of the supporting means or a bracket l8 and the elevation of the air box or the vertical position thereof with respect to the top of the pile P can be adjusted by means of the nuts IS. The pipe -I5 is also freely slidable upwardly in the bracket so that if some part of the elevator should accidentally engage the same, it can move upwardly as the elevator rises.

The bracket [8 also carries means for retaining the angular air box It! in proper angular position with respect to the corner of the pile of Any suitable means may be utilized for this purpose and that particularly illustrated includes a pair of bars 20 and 21 extending downwardly from the bracket, which bars engage one arm of the air box and thereby prevent angular displacement thereof with respect to the bracket and the corner of the pile of sheets. The bars 20 and 2| are suitably retained upon the bracket, the means particularly illustrated including a pin 22 extending through the upper end of each bar, which pin rests upon the bracket, and a cover 23 having a groove therein for each bar and being secured to the end of the bracket l8 by bolts 24. The bars are mounted so that they are freely movable upwardly.

The bar 20 upon the inner face of the air box is'wide enough to substantially close the space between the arm of the box and the side of the pile of sheets. This bar therefore also serves as an additional barricade or baffle to the escape of air and tends to direct at least some of the escaping air in an upward stream, which further aids separation of the sheets. A similar side baffle may be used upon the other arm if desired. If greater lifting or separating power of the air is desired, other bafiles may be provided, further restricting or obstructing the escape of air from beneath the sheet or sheets and also, the length of the Walls or arms of the air box may be increased.

' Means may be provided to prevent the top sheet from being raised too high. This means or stop may take any suitable form, and that particularly illustrated is a bolt 21 extending through a hole in the bracket l8 over the corner of the pile of sheets as illustrated in Figure 2. A nut 28 carried by the bolt 21 permits adjustment of v the level of the head or lower end of the bolt. It

will be observed that the air box, the bolt 21 and bars 20 and 2| merely rest upon the bracket l8 and consequently are freely movable upwardly in the event something should enga e the bottom of these parts. It is necessary, too, that the stop 21 be movable upwardly if the sheets are stlfl'. such as cardboard, because when the sheet handling means grips the sheet it raises it farther and pushes the bolt upwardly. The stop otherwise might resist the further separation and forwarding of the sheet. This yielding ofthe stop 'is of no or little importance when the sheet beimprovementsin a. sheet separator. It is under-mi. stood that various modifications in structure, as I well as changes in mode of operation, assembly,

et. Each bracket is adjustable along the cross bars towards and away from each other. A screw 3| may be used to fix the brackets in adjusted position.

When the jets of air contiguous the corners of the pile of sheets have lifted or separated the corners of the top sheets or particularly the top sheet from the underlying sheets in the'pile, a sheet handling means 33 is utilized to forward the sheet, or to further separate the top sheet from the pile of sheets in which case other devices may perform the forwarding operation, or the sheet handling means may perform both of these operations. The sheet handling means illustrated is a suction cup type, although any other type of sheet handling means may be utilized along with other jets of air which aid in separating the whole of the top sheet from the pile of sheets. The air separating means described obtains sufllcient separation of the top sheet from I the underlying sheets in the pile so that the sheet handling means may operate to grip the corners of the top sheet and continue the separation or the forwarding of the sheet from the pile.'

' The construction described herein provides at least one jet of air of a substantial length which is directed towards the edge of the top sheets of a pile of sheets and contiguous the corner thereof.

,Bafiie or wall means cooperate with the jet in that it obstructs escape of the air towards the opened orspaced edge of the separated sheet. Preferably two jets are provided which are directed so that they intermingle or their paths intersect and this creates a swirling action under the sheet or sheets which aids separation. With two jets the bame extends between the jets and may extend upon either side of each jet. The baiiie wall i at least as wide as the jets. The jets may be "positioned along the edge of the sheet but a jet at each edge adjacent or contiguous a rear corner the illustrated construction. Each rear corner of the pile is provided with a pair of jets and 'a baflie wall between the jets.

The invention includes the method by which initial separation of at least a portion of the top tap, sheets are separated from each other, how-' evehjit e secondary sheet handling means picks up-or grips the top sheet only which it is enabled todo because of the initial separation of the top sheet from thefunderlying sheet. Where a plurality'of jets are used, it is desirable to have apair' of jets intermingle' or intersect so that a swirling orflddjy'ingiofthe air is obtained under-' neath thejjsheetor'sheets. Where a plurality of jets areused; afjet may be provided at each edge of each"rear corner of the pile of sheets. 1'

1 This inventionis presented to fill a need for and manner of use,,may and oftendo occur to those skilled in the art, especially after benefiting from the teachings of an invention. Hence,

it will be understood that this disclosure is illustrative of preferred means of embodying the invention in useful form by explaining the construction, operation and advantages thereof.

What is claimedis:

1. A sheet separator for initially separating at least a portion of the top sheet of a pile of sheets so that a secondary sheet handling means may operate upon the top sheet comprising means providing a thin jet of air of substantia1 length extending crosswise of the plane-of the sheets and directed towards the edges of the sheets in the pile to raise an edge portion thereof above the underlying sheet, an air connection to the jet means, baiiie means at least as wide as the jet and extending on each side thereof to obstruct the lateral escape of air from between the sheets .at the raised edge portion thereof, the bafiie means at or adjacent at least one end thereof extending inwardly thereby spacing the loaflie means from the pile of sheets and substantially closing the escape of air at the ends of the bafile means, and means supporting the jet means so that the lower end of the jet of air is a plurality of sheets below the top of the pile of sheets and supporting the jet means and battle means in position with respect to their distance from the edge of the pile of sheets. I

2. A sheet separator for initially separating portion of at least the top sheet of a pile of sheets so that a secondary sheet handling means may operate'upon the top sheet comprising means providing a jet of air of substantial length extending cross-wise of the plane of the sheets and directed towards the edges of the sheets in the pile, a secondmeans providing a jet of air of substantial length extending cross-wise of the plane of the sheets and directed towards the edges of the sheets in the pile, the two jets being projected in a direction to intermingle at a point spaced from the edge of the sheet, an air connection to each jet means, a bailie wall extending between the two jet means and spaced from the edge ofthe pile of sheets but near enough to obstruct the lateral escape of air from between the sheets, baiile means at least at one end of the baiiie wall substantially closing the space between the baffle wall and the edge of the pile, and means supporting the jet means so that the lower end of each jet of air is a plurality of sheets below the top of the pile of sheets and extends a distance above the pile of sheets depending upon the separation desired and supporting the jet means and bailie means in position with respect to the distance from the edge of the pile of sheets.

3. A sheet separator for initially separating the corner of the top sheet of a pile of sheets so that a secondary sheet handling means may op-' erate upon the top sheet comprising an air b'ox having a pair of faces extending substantially at right angles to each other, an elongated vertical slot in each face of the air box, each slot being spaced from the corner of'the pair of faces and spaced from the end of its respective face, the slots providing a pair of thin intermingling jets of air of substantial length adapted to extend crosswise of the-plane oi the sheets, vertical baiiie means at the end of at least one face substan- 7 tially closing the space between the air box and the pile of sheets, an air connection to the box, and means supporting the air box so that the lower end of each jet of air is a plurality of sheets below the top of the pile of sheets and extends a distance above the pile of'sheets depending upon the separation desired.

4. A sheet separator for initially separating the corner of the top sheet ofa pile of sheets so that a secondary sheet handling means may operate upon the top sheet comprising an air box having a pair of faces extending substantially at right angles to each other, an elongated vertical slot ineach face of the air box, each slot being spaced from the corner of the pair of faces and spaced from the end of its respective face, the slots providing a pair of thin intermingling jets 'of air of substantial length adapted to extend cross-wise of the plane of the sheets, vertical baflle means at the end of at least one face substantially closing the space between the end of the air box and the pile of sheets, an air connection to the air box, means supporting the air box so that the lower end of each jet of air is a plurality of sheets below the top of the pile of sheets and extends a distance above the pile of sheets depending upon the separation desired and the supporting means being freely slidable upwardly.

5. A sheet separator for initially separating the comer of the top sheet of a pile of sheets so that a secondary sheet handling means may operate upon the top sheet comprising an air box having a pair of faces extending substantially at right angles to each other, an elongated vertical slot in each face of the air box, each slot being spaced from the corner of the pair of faces and spaced from the end of its respective face, the slots pro-\ viding a pair of thin intermingling jets of air of substantial length adapted to extend cross-wise of the plane of the sheets, vertica1 baflle means at the end of at least one face substantially closing the space between the endof the air box and the pile of sheets, means retaining the vertical baffle means in position for free movement upwardly, and means supporting the air vbox so that the lower end of each jet of air is a plurality of sheets below the top of the pile of sheets and extends a distance above the pile of sheets depending upon the separation desired.

6. A sheet separator for initially separating the corner of the top sheet of a pile of sheets so that a secondary sheet handling means may operate upon the top sheet comprising an air .box having a pair of faces extending substantially at right angles to each other, an elongated vertical slot in each face of the air box, each slot being spaced from the corner of the pair of faces and spaced from the end of its respective face, the slots providing a pair of thin inter-mingling jets of air of substantial length adapted to extend cross-wise of the plane of the sheets, vertical baille means at the end of at least one face substantially closing the space between the air box and the pile of sheets, means retaining the vertical baffle means in position for free movement upwardly, and means supporting the air box so that the lower end of each jet of air is a plurality of sheets below the top of the pile of sheets and extends a distance above the pile of sheets depending upon the separation desired, and the supporting means being freely slldable upwardly.

8 operate upon the top sheet comprising means providing a thin jet of air of substantial length extending crosswise of the plane of the sheets and directed towards the edges of the sheets in the pile to' raise an edge portion thereof above the underlying sheet, an air connection to the Jet means, baflle means at least as wide as the jet and extending on each side thereof to obstruct the lateral escape of air from between the sheets at the raised edge portion thereof, the baffle means being angular to extend along both edges of the corner of a pile of sheets, additional baflie means extending inwardly adjacent the ends of the next aforesaid baflle means to substantially close the escape of air at the ends of the baflle means, and means supporting the jet means so that the lower end of the jet of air is a plurality of sheets below the top of the pile of sheets and supporting the jet means and battle means in position with respect to their distance from the edge of the pile of sheets.

8. A sheet separator for initially separating a comer portion of the top sheet of a pile of sheets so that a secondary sheet handling means may operate upon the top sheet comprising means providing a jet of air of substantial length extending crosswise of the plane of the sheets and directed towards the edges of the sheets in the pile, a second means providing a jet of air of substantial length extending crosswise of the plane of the sheets and directed towards the edges of the sheets in the pile, the two jet means being adjacent to each other and both located contiguous to one corner of the pile of sheets to separate the comer portion only of the sheets, and projected at an angle with respect to each other to intermingle, the two jets being close enough so that they do intermingle between the sheets at a point spaced from the edge of the sheet, an air connection to each jet means, baflle means extending between the two jet means and obstructing the lateral escape of air from between the sheets, and means supporting the jet means so that the lower end of each jet of air is a plurality of sheets below the top of the pile of sheets and supporting the jet means and bafiie means in position with respect to their distance from the edge of the pile of sheets.

9. A sheet separator for initially separating a corner portion of the top sheet of a pile of sheets so that a secondary sheet handling means may operate upon the top sheet comprising a corner baflie having walls extending continuously from end to end thereof and at or substantiallyat right angles to extend along each edge of the corner of a pile of sheets, jet means in one wall providing a jet of air of substantial length extending crosswise of the plane of the sheets and directed towards the edges of the sheets in the pile, a second jet means in the other wall providing another jet of air of substantial length extending crosswise of the plane of the sheets and directed towards the edges of the sheets in the pile, the two jet means being contiguous to one corner of the pile of sheets to separate the corner portion only ofthe sheets, an air connection to the jet means, the walls of the baflle extending at least between the two jet means and obstructing the lateral escape of air from between the sheets, and means supporting the jet means so that the lower end of each jet of air '7. A sheetseparator for initially separating at least a portion of the top sheet of a pile of sheets so that a secondary sheet handling means may is a plurality of'sheets below the top of the pile of sheets and extends a distance above the pile of sheets and supportins the bane in position with I i 9 respect to the distance 01 the wall from the edge of the pile or sheets.

10. A sheet separator for initially separating a corner portion of the top sheet of a pile of sheets so that a secondary sheet handling means may operate upon the top sheet comprising an air :box having a wall, jet means throu .1 the wall providing a jet of air of substantial length extending crosswise of the plane of the sheets and directed towards the edges of the sheets in the pile, a second jet means through the wall providing another jet of air of substantial length extending crosswise of the plane of the sheets and directed toward the edges of the sheets in the pile, the two jet means being adjacent to each other and both located contiguous to one corner of the pile of sheets to separate the comer portion only of the sheets and projected at an angle with respect to each other to intermingle, the jet means being close enough so that the air jets therefrom do intermingle between the sheets at a point spaced from the edge of the pile of sheets, an air connection to the air box, the wall of the air box forming bafile means extending at least between the two jet means and obstructing the lateral escape of air from between the sheets, and means supporting the air box so that the lower end of each jet of air is a plurality of sheets below the top of the pile of sheets and extends a distance above the pile of sheets and supporting the air box in position with respect to the distance of the wall from the edge of 7 the pile of sheets.

prising means providing a jet of air ofsub'stan' tial length extending crosswise of the plane of the sheets and spaced from the corner along one edge of the pile, a second means providing a jet of air of substantial length extending crosswise of the plane of the sheets and spaced from the corner along the other edge of the pile of sheets, the two jet means being adjacent to each other so that the jets from the jet means intermlngle between the sheets and both located contiguous to one corner of the pile of sheets to separate the comer portion only of the sheets, an air connection to each jet means, and means supporting the jet means so that the lower end of each means also retaining the baflle means in position 10 supporting the jet means in position with respect to the corner of the pile of sheets, the supporting at the corner of the pile oi-sheets. 1

13. A sheet separator for initiallyseparating the corner portion of at least the top sheet 01' a pile of sheets so that a secondary sheet handling means may operate upon the top sheet comprising means providing a thin Jet 01' air of substan-. tial length extending crosswiseof the plane of the sheets and spaced from a comer along one edge of the pile, a second means providing a thin jet of air of substantial length extending crosswise of the plane or the sheets and spaced from the corner along the other edge of the pile, the

jet means being contiguous one comer of, the

pile of sheets to separate the corner portion only of the sheets and directed at an angle to each other so that the jets from the jet means intermingle between the sheets, an air connection to each jet means, baflle means having a wall extending at right angles with respect to each other jet of air is a plurality of sheets below the top 1 of the pile of sheets and the upper end extends a distance above the pile of sheets, the supportand between the two jet 'means and obstructing .the escape of air from between the sheets, and means supporting the jet means so that the lower end of each jet of air i a plurality of sheets below the top of the pile of sheets and extend a distance above the pile of sheets and supporting the jet means and baflle means in position with respect to their distance from the corner of the pile of sheets.

.14. A sheet separator for initiallyseparating the corner portion of at least the top sheet of a pile of sheets so that a secondary sheet handling means may operate upon the top sheet comprising an air box having a pair of faces extending at right angles. to each other, means in each face of the air box and contiguous the corner of the pair of faces for providing a thin jet of air of substantial length extending crosswise of the plane of the sheets and spaced from the corner along each edge of the pile, the jets being directed at an angle to each other so that they intermingle between the sheets to separate the corner portion only of the sheets, an air connection to each jet means, and means supporting the air box so that it is spaced from the corner of a pile of sheets with the lower end of each jet means at a distance below the top of the pile of sheets whereby a plurality of the top sheets are engaged by each' jet of air, and the air jets extending a distance above the pile of sheets greater than the level at which the secondary sheet handling means grips the top sheet.

15. A method for initially separating a corner portion of the top sheet from the-underlying sheets in a pile so that the top sheet alone can be operated upon comprising blowing a pair of jets of air of substantial length crosswis'e of the extending crosswise of the plane of the sheets and contiguous a corner of the pile of sheets to separate the corner portion only of the sheets and.

impinging at least one edge of the pile, an air that the lower end of the jet is a plurality of sheets below the top of the pil of sheets and plane of the sheets and so that the lower portion of each jet engages a plurality of the top sheets of the pile, locating the jets adjacent to each other and contiguous a corner of the pile of sheets to separate the corner portion only of the sheets,

the air for the jets having a pressure to separate and retain separated the top sheets from each other, directing the jets at an angle to each other so that they intermingle at a point over and between the sheets, and obstructing the escape of air from between the sheets at the corner of the pile oi. sheets.

16. A method for initially separating a corner portion of the top sheet from the underlying sheets in a pile so that the top sheet alone can extends" a distance above the pile of sheets and 76 be operated upon comprising blowing a pair of 11 jets of air of substantial length crosswise of the .plane of the sheets and so that the lower portion of each jet engages a plurality of the portion of the top sheet from the underlying sheets in a pile so that the top sheet alone canbe operated upon comprising blowing a pair of jets of air of substantial length crosswise of the plane of the sheets and so that the lower portion of each jet engages a plurality of the-top sheets of the pile, directing one jet at each edge of the pile contiguous a corner thereof to separate the comer portion only of the sheets, the air for the jets having a pressure to separate and retain separated the comer portions onlyof the top sheets from each other, directing the jets at an angle to each other so that they intermingle at a point over and between the sheets, and obstructing the escape of air from between the sheets and at each edge of the corner of the pile of sheets.

18. ,A method for pneumatically separating a corner portion of at least the top sheet from a side of said pile of sheets, directing the jet at the pile spaced from but contiguous the corner length crosswise of the. plane of the sheets and w so that the lower portion of each jet engages 'a plurality of the top sheets of the pile, directing uous each corner thereof, the air for the jets having a pressure to separate and ,retain separated the corner portions only of the top sheets from each other, and obstructing the escape of air from between the sheets in at least the space between the adjacent jets.

20. A method for initially separating corner portions of a pair of corners of the top sheet from the underlying sheets in a pile so that the top sheet alone can be operated upon comprising blowing a plurality of jets of air of substantial length crosswise of the plane of the sheets and so that 'the lower portion of each jet engages a plurality of the top sheets of the pile, directing one jet at each side edge of the pile contiguous a corner thereof, directing a jet at the adjacent transverse edge contiguous each corner thereof of said pile of sheets to separate the corner portions only of the sheets, the air for the jet having a pressure sufllcient to separate and retain separated the corner portions of the top sheets from each other, and obstructing the escape of air from between the sheets at the corner of the pile and. continuously along each edge at least to the jet and create a turbulence of air between two or or more of the topmost sheets of said pile to separate the corner portions only of the sheets, the air for the jets having a pressure to separate and retain separated the corner portions of the top sheets from each other, directing adjacent jets at an angle 'to each other so that they intermingle at a point over and between the sheets, and obstructing the escape of air from between the sheets at least between the adjacent jets.

21. A method for initially separating comer portions of a pair of corners of the top sheet from the underlying sheets in a pile so that the top sheet alone can be operated upon comprising blowing a plurality of jets of air of substantial length crosswise of the plane of the sheets and so that the lower portion of each jet engages a plurality of the top sheets of the pile, directing one jet at each side edge of the pile contiguous a corner thereof, directing a jet at the adjacent.

transverse edge contiguous each corner thereof, directing adjacent jets at an angle to each other so that they intermingle at a point over and between the sheets to create turbulence therebetween, and the air supplied to the jets having a pressure to separate and retain separated the corner portions only of the top sheets from each other.

' JOHN R. PERRY.

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