US2182435A - Sheet feeding mechanism - Google Patents

Description

Dec. 5, 1939. w. F. HUCK SHEET FEEDING MECHAQISM Filed July 25, 1935 7 Sheets-Sheet l Dec. 5, 1939. w. F. HUCK 2,182,435

SHEET FEEDING MECHANISM Filed July 25, 1935 '7 Sheets-Sheet 2 mvzu'roa.

Dec. 5, W. F. HUCK SHEET FEEDING MECHANISM Filed July 25, 1935 7 SheerQs-Sheet 5 Dec. 5, 1939. w E uc 2,182,435

SHEET FEEDING MECHANISM I Filed July 25, 1935 7 Sheets-Sheet 4 INVENTCaR. B

Dec. 5, 1939. w F, H CK 2,182,435

SHEET FEEDING'MECHANISM Filed Jilly 25, 1935 7 Sheets-Sheet 5 Dec. 5, 1939. w. F." HUCK 2,132,435

SHEET FEEDING MECHANISM Filed Jul 25, 1935 v sheets-sheets nan-m.

. 5, 1939. w. F. HUCK SHEET FEEDING MECHANISM Filed July 25, 1935 7 Sheets-Sheet 7 Patented Dec. 5, 1939 UNITED STATES PATENT OFFICE to It. Hoe & 00., Inc., poration of New York New York, N. Y., a cor- Application July 25, 1935, Serial No. 33,142

17 Claims.

This invention relates to feeding mechanism and more particularly to sheet or plate feeding mechanism for use in printing machines.

In printing sheets of metal, card-board or other material of substantial body, the sheets are first stacked upon each other to form a pile, and the sheets are fed preferably one at a time from the top of the pile by a suitable feeding device to the printing mechanism, and, in the present instance, the sheets are printed on a rotary tin or sheet metal printing machine of the offset type.

In removing the top sheet from the pile preparatory to conveying it to the printing mechanism by suitable feeding instrumentalities, diificulty is experienced in separating the top sheet from the pile owing to the tendency of the sheet to adhere to the pile either by the effect of static electricity or the adhesive characteristics of the coating or treating material that may be present on the surao face of the sheet, therefore, an object of this invention is to provide a sheet feeding mechanism for positively separating each sheet from the pile preparatory to conveying the sheet to the printing mechanism.

25 Another object of this invention is to provide a sheet feeding mechanism for printing machines incorporating means for buckling the top sheets of a sheet pile preparatory to engaging the top sheet by a suitable suction head or sucker and 3a conveying the top sheet by an improved conveying mechanism to the printing mechanism, the conveying mechanism being operated in definite cooperative relation to the feeding and printing mechanism.

5 A more specific object of this invention is to provide in a sheet feeding mechanism novel means for buckling the top sheets of a feeding pile, the buckling means so engaging the sheets that the top sheets are progressively buckled a 4G greater extent as the sheets are positioned toward the top of the pile, thus entirely separating the top sheet from the remainder of the pile before being engaged bythe conveying mechanism.

A further object of this invention is to provide 45 a sheet feeding mechanism for a printing machine in which the top sheet of a feeding pile is engaged by an improved vacuum or suction head. and the suction head and sheet conveyed through a predetermined path of travel to and from the 50 printed mechanism by a novel composite link construction positively operated by adriven component of the printing machine.

Another object of this invention is to provide a sheet feeding mechanism for a printing ma- 55 chine incorporating automatic means for maintaining the pile of sheets to be fed to the printing mechanism in predetermined relation to the feeding mechanism by improved instrumentalities, and, also, including means for positively raising I, and lowering the sheet pile through manually 6 controlled power operated instrumentalities independently of the automatic power controlling and operating mechanism.

One of the more specific objects of the inven-. tion is to provide a sucker in the form of a 10 suction or vacuum head for conveying the sheets from the sheet pile to the printing mechanism, and incorporating simple and positively actuated valve and valve controlling mechanism for positively communicating the suction head to the vacuum pump during the feeding operation, and for communicating the head with the atmosphere to release the feeding sheet.

It is also an object of this invention to provide for use in printing machines a sheet feeding mechanism of generally improved construction, whereby the device will be simple, durable and inexpensive in construction, as well as con- Venient, practical, serviceable and efflcient in its use.

With the foregoing and other objects in View, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts, and in the details of construction hereinafter described and claimed, it being understood that various changes in form, proportion, and minor details of construction may be made within the scope of the claims without departing from the spirit or sacrificing any advantages of the invention.

For a complete disclosure of the invention, a detail description of an improved sheet feeding mechanism for printing machines will now be given in connection with the accompanying drawings forming a part of the specification wherein: 40

Figure 1 is a fragmental side elevation of an offset sheet or metal printing machine showing the invention applied thereto;

Figure 2 is a detailed diagrammatic view showing the relationship of the components of the improved buckling mechanism and the sheet conveying suction head;

Figure 3 is an enlarged fragmental elevation depicting the suction head and cooperating mechanism, the path of travel of the suction head being shown in dotted lines, and its direction of movement indicated by arrows;

Figure 4 is a fragmental elevation showing the clutch and drive mechanism in the pile hoist u operating device, the view looking in the direction of arrow 4 Figure 11;

Figure 5 is a detailed vertical sectional view taken through the improved sheet buckling roller and supporting frame;

Figure 6 is a fragmental plan view depicting the mechanism for adjusting the thrust block or jaw of the improved sheet buckling device;

Figure 7 is a sectional view taken through the improved crank mechanism for operating the suction head;

Figure 8 is a longitudinal sectional view taken through the valve and valve housing for controlling the communication between the suction head and a suitable vacuum producing source;

Figure 9 is a detailed transverse sectional view of the valve and housing, taken on the line 9-9 of Figure 8;

Figure 10 is a similar view showing the valve in another position;

Figure 11 is a vertical detailed sectional view, parts shown in elevation, taken through the drive end of the improved pile hoist driving mechanism;

Figure 12 is a detailed sectional view taken on the line |2|2 of Figure 11;

I Figure 13 is a detailed elevation showing the means for securing the drive gear to the pile hoist screw;

Figure 14 is a detailed vertical sectional view similar to Figure 11 but showing the opposed end of the pile hoist driving mechanism;

Figure 15' is a fragmental elevation depicting the improved safety foot for cooperating with the sheet pile;

Figure 16 is a fragmental plan view of the improved safety foot and supporting mechanism,

the'view being taken in the direction of arrow printing sheet tin, cardboard or other sheet material of substantial body. The side members of the frame 22 are provided with inwardly extending portions 21 having guide ways or surfaces 28 machined or otherwise formed therein for the sliding reception of supporting lugs 38 extending from platform brackets 3|, which are, in turn, suitably secured to the pile hoist platform 32, and the supporting lugs 38 are retained for vertical sliding movement within the guide ways 28 by guide or retaining bars 33. The platform 32 is arranged to support a number of superposed sheets of material to be printed, and in the present instance a plurality of sheets of tin I are illustrated to form the sheet pile, although it is to be understood that any other suitable material of substantial body may be printed and handled in this mechanism. The sheet pile is controlled by and cooperates with instrumentalities of the mechanism to be hereinafter disclosed.

In order to raise and lower the pile platform 32, a pile hoist mechanism is provided which includes a shaft 35 extending transversely across the machine and mounted for both rotating and sliding movement. The opposed terminals of the shaft 35 are slidably mounted in sleeves 36 rotatably supported by antifriction bearings 31, and the shaft 35 is secured against rotary motion relative to the sleeves 36 by suitable keys 38. Each sleeve 36 is keyed or otherwise suitably secured to a beveled gear 48 which meshes with a beveled pinion 4| rotatably mounted on antifriction bearings 42 supported by a cross brace or rail 43 of the machine frame. A threaded screw 44 is secured to each pinion 4| by suitable pins or keys 45, and a retaining collar 46 is suitably secured to each screw 44 and engages the lower surface of the rail 43 to hold the pinions 4| on the bearings 42 in correct operating position. The supporting lugs 38 of the platform brackets 3| are provided with threaded apertures 41 for the reception of the screws 44, thereby raising and lowering the pile platform when the screws are rotated, as will be hereinafter more fully disclosed.

In order to quickly raise and lower the pile platform to load the platform or to bring the top sheet in proper cooperative relation with other instrumentalities of the feeding mechanism, a reversible push button control motor 48 of the usual commercial type is provided and is suitably secured to the machine frame, as indicated at 49, and this motor is, in turn, connected through the usual commercial worm reduction gear 50 to a stub shaft 5| having a clutch sleeve 52 rigidly secured thereto, and this clutch sleeve is provided with radially extending clutch teeth 53. The end of the shaft 35 which is disposed toward the drive motor 48 is provided with a clutch head 55 which is rigidly secured to the shaft 35, and this clutch head is provided with radially extending teeth 56 for engagement with the teeth 53, as will be hereinafter more fully disclosed; The gears 40 and 4| are positioned in suitable housings 51, and the housing which is positioned toward the drive motor 48 is provided with a bracket 58 in which a lever 60 is pivotally mounted, as indicated at 6|. One end of the lever 60 is bifurcated and straddles the clutch head 55, and carries inwardly extending rollers 62 positioned in an annular groove 63 formed in the clutch head 55, to thereby move the shaft 35 longitudinally when the manipulating handle of the lever 60 is moved by an operator. When the operator moves the manipulating handle of the.

lever 68 and forces the teeth 56 into engagement with the teeth 53, the shaft 35 is then coupled to the drive motor 48, and the operator may raise and lower the pile of sheets T by simply pressing the usual raising and lowering controlling button, not shown, thus controlling the current supplied to the motor 48.

In order to properly feed the sheets T to the printing rollers 25 and 26 of .the printing antifriction bearings 66 carried in a cross brace or frame 61 of the machine frame. The bearing portions 68 of each shaft 65 are arranged eccentrically with relation to the shaft body. and the shaft body has spaced antifriction bearings 10 suitably mounted thereon for rotatably supporting a tubular member or shell II arranged to 2,182,485 engage the longitudinal edges of the top sheets of the sheet pile, as will be apparent from the disclosures hereinafter made. The outer eccentric bearing portion 68 of each shaft 65 has a sprocket I2 rigidly secured thereto, and each sprocket I2 is driven by a chain I3 from a sprocket I4, indicated in dotted lines in Figure 1 of the drawings. A tubular nut I5 is positioned at each side of the machine adjacent the upper terminal of the sheet pile, and each nut I5 is swiveled to the machine frame, as indi cated at I6. A threaded screw rod TI is rotatably received within an axially extending threaded aperture I8 formed in each tubular nut 15, and the outer end of each screw 11 has a worm wheel secured thereto. A worm 8I meshes with each worm wheel 80, and the worms 8| are mounted on a transversely extending shaft 82 rotatably mounted in spaced bearings 83 extending from a thrust or buckling jaw 85, and the terminal of each screw 11 which is positioned toward the thrust jaw 85 is swiveled within the thrust jaw or block, as indicated at 86, and a manipulating handle 81 is secured to one end of the transverse shaft 82, so that by rotating the shaft 82 the worms 8| rotate the worm gears 80, thereby causing the screws II to turn in the tubular threaded nuts I5 and move the thrust jaw to and from the tubular buckling member II, for reasons to be hereinafter pointed out. A shoulder 88 extends longitudinally along the inner vertical face of the thrust jaw 85 and engages and rests on the longitudinal edge of the top sheet T of the sheet pile. To counter-balance the weight of the suspended thrust jaw, an ear 90 extends downwardly from each tubular nut I5, and each ear is pivotally secured to a rod 9I having a helical extension spring 92 mounted thereon and arranged to exert an outward tension against the ear 90 to counter-balance the weight of the thrust or buckling jaw 85.

In order to automatically maintain the top sheet of the sheet pile at a predetermined height or in predetermined relation to the feeding mechanism, to be hereinafter disclosed, the shaft 35 is provided, adjacent its terminal which is removed from the drive motor 48, with a ratchet 93 which is normally loosely mounted on the shaft 35, but may be locked against rotation relative to the shaft 35 by means of a key 95-which extends through a slot 96 in the shaft 35 and engages recesses 91 formed in the ratchet 93 when the shaft is moved in the direction away from the drive motor 48. The ratchet 93 is provided with a plurality of peripheral recesses or teeth 98 to be operably engaged by a pawl I00, which is secured to a rod or shaft IOI, as indicated at I02 in Figure 14, and the pawl shaft IN is carried by spaced arms I03, which are, in turn, rotatably mounted on flanged bearings I05 carried by the frame 22, and bracket 31. A control finger I06 is secured to the pawl shaft IBI, as indicated at ID? in Figure 14, and this control finger I06 cooperates with a control arm I08, best shown in Figure 1 of the drawings, for the purpose to be hereinafter pointed out. The spaced pawl actuating arms I03 are oscillated to actuate the pawl by means of an eccentric disc III) secured to and forming a part of a composite crank mechanism to be hereinafter explained, and this disc H0 is pivotally secured to a link I I I, as shown in Figures 1 and 7. The outer terminal of the link III is pivotally secured to a bell crank lever II2, which, in turn, is pivotally secured to a link or rod I I3, and the outer end of the rod I I3 is pivotally secured to arms IIB secured to the arms I03. Thus, it is seen, as the disc H0 is rotated, the link II I, bell crank H2, rod H3, arms II 4 and I03 move the pawl about the shaft 35, thus rotating the ratchet 93 in a clock wise direction, as indicated in Figure 1. when the components are in a position to permit the operable engagement of the pawl I00 with the ratchet 93.

In feeding sheet material to the printing cylinders 25 and 26 of the printing press, it is highly desirable that the sheets T be fed from the sheet pile in a direct path of travel to the feed table and forwarding rollers, and at a speed which during a portion of the feeding travel coincides with the speed of travel of the sheet from the forwarding rollers to the printing cylinders. To accomplish this, applicant provides a suction cup H5 preferably formed of elastic material, such as rubber, and having a disc shaped dished tapered portion 6 for engaging the upper surface of the sheet T, and suitable spaced ribs III are provided to maintain the cup in proper shape by adding the necessary rigidity thereto, but, at the same time, permitting the cup to yieldingly engage the curved surface of the top buckled sheet T and to conform accurately to this surface in order that a suction may be produced. The suction cup or head I I5 is secured to a valve housing IIB by suitable screws or fastening devices I28. The valve housing II8 has spaced tubular members I2I secured therein to provide a cylindrical chamber I22 for the reception of the cylindrical valve I23, and the outer terminal portions of the tubular members I2I have relatively short pipe sections I25 rigidly secured thereto and communicating therewith. Spaced arms I25 are pivotally secured around the tubular members I2I, as best shown in Figure 8. These arms are pivotally secured at I2I to arms I28, and in order to permit a yielding motion between the short spaced arms I26 and the supporting arms I28, a rod I30 is pivotally secured to each arm I28 and has a helical extension spring I3I positioned therearound and arranged to engage the free terminal of the arm I28 in order that each arm I26 may yield relative to its supporting arm I28 to permit the suction head to yield and conform to the curve surface of the top metal sheet T. The outer terminal of each pipe section I25 is swiveled to an intermediate obliquely-disposed pipe section I32, and the lower terminal of each intermediate pipe section I82 is swiveled to a rigid pipe section I33, which, in turn, leads to a suitable vacuum producing instrumentality, such as a vacuum pump or the like, not shown. The supporting arms I28 are carried by mechanisms provided at each side of the machine, and, of course, a description of the mechanism at one side will describe the duplicate mechanism at the other. Each supporting arm I28 is pivotally secured. at its lower terminal, as indicated at I35, to a link I36, and the opposed terminal of the link I36 is movably secured to a composite crank member ISI on antifriction bearings I38, as best shown in Figure 7 of the drawings. Each composite crank I3? is supported for rotary movement by the machine frame 22 and a bracket 20 on interposed antifriction bearings I60 and MI respectively, these bearings being maintained in operative position in any preferred manner. A shaft. I62 extends transversely across the machine and has each terminal secured to and against rotation relative to each composite crank member I37 by means of a key I43, screw I,

and washer I45. Each disc I I8 is positioned to align with "the shaft I42 so that when the shaft I42 and composite crank members I31 rotate they also rotate the discs I I8, thus imparting motion to the ratchet pawl I88 through the hereinbefore described instrumentalities. Each composite crank member I31 is provided with a second antifriction crank bearing I46 on which is rotatably mounted a link I41, and the outer terminal of this link I41 is pivotally secured to a floating bell crank I48, as indicated at I58. The intermediate portion of the floating bell crank I48 is pivotally secured to an intermediate portion of the supporting arm I28, as indicated at II, and the terminal of the floating bell crank I48 which is remote from the terminal I 58 is pivotally secured to an intermediate portion of the link I36, as indicated at I52. Any suitable means may be provided for driving the shaft I42, composite eccentrics I31 and discs II8,'and a preferred mechanism for this purpose includes a gear I53 carried by the shaft I42, driven by a gear I55, mounted on a shaft I 56, as best shown in Figure l of the drawings. The shaft I56 is driven from a stub shaft I51 through intermeshing beveled gears I58 and I68, and the stub shaft, in turn, is driven from a gear train of any preferred type driven from an operating component of the printing machine. Such mechanism is depicted diagrammatically in Figure 1 of the drawmgs.

The suction head grips the buckled sheets and conveys them from the sheet pile, as will be hereinafter more fully disclosed, and deposits each sheet on a feed'table I 6I of usual construction into the bite of a driven forwarding roller I62 and a cooperating pressure roller I63, each bearing of the pressure roller I63 being rotatably mounted in a bracket I64, as indicated at I65, and the brackets I64 are mounted for pivotal movement on a transverse shaft-I66, each bracket being stressed toward the driven forwarding roller I62 by means of a helical extension spring I61 which is interposed between a cupped extension I68 of the bracket I64 and a rigid lug I18. One of the brackets I64 is provided with an extending finger I1I which engages a terminal I12 of a bell crank I13 which is fulcrumed at I15, and the terminal I 12 of the bell crank is normally stressed toward the finger "I by a helical extension spring I 16. The upper terminal I14 of the bell crank I13 is positioned adjacent an operating button or component of the usual commercial limit switch I11 to engage the button and break the electric circuit to the usual driving motor, not shown, when more than one thickness or sheet T of material is fed between the driven forwarding roller I62 and the yieldable pressure roller I63. As the suction head II5 deposits the sheet T upon the feed table I6I, and while the suction head is still moving forwardly, the sheet is engaged by the forwarding and pressure rollers I62 and I63. After the suction head II5 moves from engagement with the sheet T, one of the preferably spring pressed pusher fingers I18, carried by a driven chain I88, then engages the rear terminal of the sheet T and cooperates with the forwarding and pressure rollers I62 and I63 in feeding the sheet to grippers I8I carried by the impression cylinder 26, thus causing the sheet T to be fed for printing between the blanket cylinder 25 and impression cylinder 26.

In order that the suction head or cup I I5 may be communicated with the vacuum source during a phase of its operation, and communicated with the atmosphere during another phase of its operation, the valve I23 is provided with a port I 82 which communicates .with a port I83 formed in the valve housing I I8 and the suction cup H5.

The valve I23 has a bifurcated arm I85 secured,

thereto, as indicated at I 86, and extending radially therefrom. A roller I81 is mounted for rotation at theouter terminal of the bifurcated arm I85, as indicated at I88, and this roller engages a cam or abutment I98 when the suction head is moved toward the sheet pile, thereby rocking the valve I 23 so that the ports I82 and I83 register, thus communicating the suction head or cup with the vacuum source through the port I83, port I82, valve I23, tubular members I2I, short pipe sections I25, intermediate pipe section I 32, rigid pipe section I 33 to the usual vacuum pump, not shown. When the suction head is moved towards the printing cylinders, the roller I81 engages a cam or abutment plate I9I, thereby rocking the valve I23 so that a by-pass port I92 formed in its peripheral portion registers with an outlet port I93, formed in the valve housing, and with the port I83, thus causing the vacuum cup to communicate with the atmosphere, thereby breaking the vacuum to release the sheet from the suction head so that it may be deposited on the feed table I6I.

To provide a safety deviceto insure the top sheets T of the sheet pile stopping at the correct or predetermined height when the pile platform is being elevated, the lever 60 has one end of a rod I95 pivotally connected thereto, as shown at I94 in Figure 4, and the opposed end of the rod I95 is pivotally connected to an arm I96, as indicated at I91, in Figure 15. The arm I96 is pivotally secured at its upper terminal to the brace or member 43 of the machine frame, as indicated at I98, and the lower terminal of the arm I96 has a safety member I99 pivotally secured thereto, as indicated at 288. The safety member I 99 is in the form of a bell crank having an upwardly extending lever portion 28I, normally stressed away from the arm I96 by a spring 282, mounted on a rod 283 operably interposed between the lever 28I and arm I96, and the outward movement of the lever 28I under the stress of'the spring 282 is limited by a pin or stud 284 carried by the arm I96, as best shown in Figure 15. A pressure foot 285 extends from the lower portion of the bell crank I99, and this foot is to be engaged by the top sheet T of the pile to operate the safety device, as will be hereinafter disclosed. A commercial limit switch 286 of the conventional type is carried by the machine frame, and this switch is provided with a swinging or rocking arm 281 having a manipulating roller 288 pivotally secured to one terminal, and this roller cooperates with the lever 28I, as will be presently explained. When the top sheet T of the sheet 'pile has beenelevated to the desired or predetermined height, this sheet engages the pressure foot 285 and moves it upwardly, thus swinging the lever 28I against the tension of the spring 282 away from the roller 288 of the limit switch 286, thus causing the spring-actuated arm 281 of the switch to move outwardly to the full line position indicated in Figure 15, thus breaking the circuit to the motor 48, thereby arresting the elevating movement of the pile platform. Againf'if an operator should attempt to manipulate the lever 68 preparatory to elevating the pile when the top sheet is at or above the predetermined height, the movement of the lever 68 toward clutch-engaging position would cause the pressure foot 265 to engage the top sheet of the pile, thus preventing the lever 20! from moving the limit switch to operating position, thereby preventing the further elevation of the sheet pile.

In operation, if it is desired to quickly elevate or lower the pile platform, this may be done by manipulating the lever 60 to move the teeth 56 of the clutch head 55 into engagement with the clutch teeth 53 of the clutch sleeve 52, and then manipulating the conventional controlling push button for the motor 48, thereby rotating the screw 46 through the described mechanism,

thus quickly raising and lowering the sheet pile.

When the top sheet of the pile reaches the desired or predetermined height, it engages the pressure foot 205 of the safety device, thus breaking the electric circuit through the limit switch 206 to the pile platform driving motor 48. After the top sheet has been elevated to the predetermined height, the lever 50 is manipulated to disengage the clutch head 55 from the driving clutch sleeve 52, thus moving the key 95 to engagement with the ratchet 93 to cause the ratchet to be operably connected with the screws 4% through the disclosed mechanism. As the shaft I42 rotates to impart movement to the suction head. it also rotates the disc I10, thereby rocking the pawl I00, through the interposed mechanism hereinbefore disclosed, thus causing the pawl to engage the teeth 98 of the ratchet 93 and impart rotary motion to the ratchet. Whenever the top sheet of the pile is below the predetermined height, the thrust block or law 85, which is supported on the upper sheet of the pile by its shoulder 88, causes the control arm I08 to be moved from below the control finger I06, thus permitting the pawl to operably engage the ratchet. However, when the top sheet approaches the predetermined height, the upward movement of the thrust block or jaw 85 swings the control arm I08 under the control finger Hi6, thus locking the pawl from operable engagement with the ratchet, thereby arresting the upward movement of the pile. The pile supporting platform remains in this position until a sufficient number of the sheets have been fed to the printing mechanism to lower the top sheet below the predetermined height, when the control arm its will again .release the control finger we, thus permitting the pawl 698 to engage the ratchet 93 to again elevate the pile.

Rotation of the shaft M2 rotates the composite cranks i3? positioned at each end thereof, and the rotation of these cranks cause the lower terminals of the links we and it! to move in circular paths of travel coinciding with the circular movement of the bearings i38 and M5, and these links i315 and It? impart movement to the supporting arms I28, through the interposed bell crank levers H38, and the movement of the outer terminal of the supporting arms I28 is influenced by the movement of the swiveled pipe sections 125 and H32, thus causing the suction head M5 to move directly in a short path of travel from the sheet pile to the feed table and to return through a greater arcuate path of travel, as best indicated in Figure 3 of the drawing. Furthermore, during a portion of the movement of the suction head or cup H5 from the pile to the feed table, this suction head moves forwardly at the same speed as the sheets are propelled by the forwarding andpressure rollers I62 and IE3, therefore, it is obvious, that as the suction head, at the terminal of its 36 forwarding movement, moves away from the forwarding path of travel, there is no interruption or break in the continuous feeding movement of the sheet because, as stated, the forwarding and pressure rollers I62 and I63 and the suction head H5 move the sheet forwardly at precisely the same speed. After the suction head conveys the sheet into the bite of the forwarding and pressure rollcrs I62 and I63, and the sheet moved a distance forwardly by these rollers, a pusher finger I18, in its turn, engages and feeds the sheet to the gripper l8l of the impression cylinder 26, as hereinbefore disclosed, which causes the sheet to be fed in the usual'manner between the impression cylinder 26 and the blanket cylinder 25 of the printing machine.

The thrust block or jaw 85 may be adjustably moved along the screws H by simply rotating the I handle 81, which causes the shaft 82 to rotate the By interposing the sheets T of the pile to be buckled between the rigid but adjustable jaw 85 and the bodily movable and rotatable cylindrical member H, great pressure or stress may be exerted against the edge of the sheets without unduly wearing the outer surface of the cylindrical member I l because, as hereinbefore disclosed, the cylindrical member is free to rotate so that-different portions of its peripheral surface is presented to the edges of the engaged sheets during the buckling operations, thereby prolonging the operative life of the buckling mechanism. The cylindrical buckling member H is arranged so that its greatest lateral dimension is presented to the top sheet T of the sheet pile thereby causing the peripheral surface of the cylindrical member to engage the sheets of the pile which are positioned below the top sheet at points positioned inwardly relative to the point at which the cylindrical member engages the top sheet to so buckle the sheets that the degree of bucklingin each sheet is progressively increased as the sheet is positioned towardsthe top of the pile to insure the effective separation of the top sheet T from the pile before it is engaged by the disclosed suction head.

What I claim is: 1

1. In a sheet feeding mechanism for printing machines, means for supporting a pile of sheets, means engaging the vertical edges of the sheets for buckling upwardly a plurality of sheets located at the top of the pile so that the degree of buckling of each sheet is progressively increased as the sheets are located progressively nearer the top of the pile, and a suction head movable to engage the top buckled sheet of the pile and convey it from the pile towards the printing mechanism of the printing machine.

2. In a sheet feeding mechanism for a printing machine, means for supporting a pile of sheets, means for buckling a plurality of the sheets positioned at the top of the pile so that the degree of buckling is progressively increased in each sheet as the sheet is positioned towards the top of the pile, and a suction head movable through different paths of travel and operable to engage the top buckled sheet and convey it from the pile towards the printing mechanism of the printing machine.

3. In a sheet feeding mechanism for a printing machine, means for supporting a pile of vertically 'alined superposed sheets, a suction head for engaging and adhering to the top sheet of the pile,

and means for moving the suction head upwardly 76 and then in a relatively short straight path of travel from the pile directly towards the printing mechanism of the printing machine'and for returning the suction head to the pile through a different longer path of travel directly above the first path of travel.

4. In a sheet feeding mechanism for a-prin'ting machine, means for supporting a pile of vertically alined superposed sheets, a suction head for-en- 10 gaging and adhering to the top sheet of the pile,

and means for moving the suction head in a substantially straight horizontal path of travel of given length from the pile in a direction directly towards the printing mechanism of the printing machine and for returning the suction head to the pile through another arcuate path of travel of greater length directly above the first path of travel.

5. In a sheet feeding mechanism for a printing machine, means for supporting a pile of sheets, a suction head for engaging and adhering to the top sheet of the pile, a conveyor mechanism movable from a point between the pile and the printing mechanism of the printing machine in a direction towards the printing machine at a given speed to convey the sheet from the said point to the printing mechanism, and means for moving the suction head from the point at which it adheres to the sheet first upwardly from the pile and then in a direct substantially horizontal path of travel of given length in a direction towards the conveyor mechanism to convey the sheet to the conveyor mechanism and from there through an arcuate path of travel of greater length in a direction away from the conveyor mechanism along a path of travel located directly above the said horizontal path back to the pile of sheets.

6. In a sheet feeding mechanism for printing machines, means for supporting a pile of vertically alined superposed sheets, a suction head for engaging and adhering to the top sheet of the pile, a conveyor mechanism movable towards the printing mechanism of the printing machine at a given speed to convey sheets to the printing mechanism,and means for moving the suction head first upwardly from the point at which it engages and adheres to the sheet and in a direct substantially horizontal path of travel from the pile to the conveyor mechanism to convey the sheet from the pile to the conveyor mechanism, the suction head moving in a portion of the path of travel at a speed equal to the speed of the conveyor mechanism and movable in other portions of the path of travel at a different speed. 7 In a sheet feeding mechanism for printing machines, means for supporting a pile of sheets,

a suction head for engaging and adhering to the top sheet of the pile, a conveyor mechanism mov- 0 able substantially horizontal in a direction from the pile towards the printing mechanism of the printing machine at a given speed to convey.

sheets to the printing mechanism, and means for moving the suction head in a substantially hori- 5 zontal direct path of travel from the pile to the conveyor mechanism at a speed equal to the speed of horizontal travel of theconveyor mechanism to convey sheets from the pile to the conveyor mechanism and for returning the suction head from the conveyor to the pile through another longer path of travel at a different speed.'

8. In a sheet feeding mechanism, means for supporting a pile of sheets, a jaw engaging an edge of each of a pluralityof sheets positioned 7 at the top of the pile, a rotatable member engaging the opposed edge of each of the same sheets and movable bodily toward the jaw for buckling the sheets between the movable member and the jaw.

9. In a sheet feeding mechanism, means for 5 supporting a pile of sheets, a jaw engagingan edge of each of a plurality of sheets positioned at the top of the pile, a rotatable cylindrical member engaging the opposed edge of each of the same sheets and movable bodily toward the jaw 10 to buckle the sheets between the cylindrical member and the jaw.

10. In a sheet feeding mechanism, means for supporting a pile of sheets, a jaw engaging an edge of each of a plurality of sheets which are 15 positioned at the top of the pile, a cylindrical member mounted for turning movement on bearings and engaging the opposed edge of each of the sheets which are engaged by the jaw, the cylindrical member being movable bodily towards 20 the jaw to buckle the engaged sheets between the cylindrical member and the jaw.

11. In a sheet feeding mechanism, means for supporting a pile of sheets, a jaw engaging "one edge of each of a plurality of the sheets which 25 are positioned at the top of the pile, a cylindrical member mounted for turning movement on bearings and engaging the opposed edge of each of the sheets which are engaged by the jaw, means for driving the cylindrical member to move it 30 bodily towards the jaw to thereby buckle the engaged sheets between the cylindrical member and the jaw.

12. In a sheet feeding mechanism, means for supporting a pile of sheets, a jaw engaging one 35 edge of each of a plurality of the sheets which are positioned at the top of the pile, means for rotatably supporting a shaft having an eccentric portion, a cylindrical member mounted for tuming movement on the eccentric portion of the shaft and engaging the opposed edge of each of the sheets which are engaged by the jaw, and means for rotating the shaft thereby causing its eccentric portion to bodily move the cylindrical member towards the jaw to thereby buckle the 5 engaged sheets between the cylindrical member and the jaw.

13. In a sheet feeding mechanism, means for supporting a pile of sheets, a jaw engaging one edge of each of a plurality of the sheets which 0 are positioned at the top of the pile, a rotatable cylindrical member engaging the opposed edge of each of the same sheets and positioned so that its greatest diameter engages the top sheet, and means for bodily moving the cylindrical member towards the jaw for buckling the sheets so that the degree of buckling is progressively increased in each sheet as the sheet is positioned toward the top of the pile.

14. In a sheet feeding mechanism for printing '0 machines, means for supporting a pile of sheets,

a suction head for engaging and adhering to the top sheet of the pile, swiveled pipe sections communicating the suction head witha vacuum producing source, and a driven composite mechanism coacting with the swiveled pipe sections to support and move the suction head through one path of travel from the pile towards the printing mechanism and through a greater path of travel back to the pile. 7o

15. In a sheet feeding mechanism, means for supporting a pile of sheets, a. jaw engaging the edges of some of the sheets, a cylindrical member engaging the opposed edges of the sheets which are engaged by the jaw, the cylindrical member being mounted for tree rotation to present different portions of its peripheral surface to engage the sheets and movable bodily towards the jaw to buckle the engaged sheets between the cylindrical member and the jaw.

16. In a sheet feeding mechanism for printing machines, means for supporting a pile of sheets, a suction head for engaging and adhering to the top sheet of the pile, swiveled pipe sections communicating the suction head with a vacuum-producing source, a driven crank mechanism, a supporting arm yieldably secured to the suction head, movable members operably interposed between the crank member and the supporting arm, the swiveled pipe sections, crank member, supporting arm and interposed movable member cooperating to move the suction head in a short path of travel from the pile towards the printing mechanism and through a greater path of travel back to the pile.

17. In a sheet feeding mechanism for a printing machine, means for supporting a pile of sheets, a suction head, means for moving the suction head in a direct path of travel from the pile towards the printing mechanism of the printing machine and for returning the head through a greater path of travel to the pile, abutments positioned in the paths of travel of the suction head, swiveled pipe sections leading from a vacuum-producing source to the suction head, a valve carried by the suction head and operably inter-' posed between the suction head and swiveled pipes, the valve engaging the abutments when the suction head is moved in its paths of travel to move the valve to either vacuum connection or break positions to thereby cause the suction head to adhere to or release the top sheet of the.

pile. 1

WILLIAM F. HUCK.

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