US3370845A - Sheet feeding apparatus - Google Patents

Description

Feb. 27, 1968 R K, NEWCOMB 3,370,845

SHEET FEEDING APPARATUS Filed Sept. 7, 1965 3 Sheets-Sheet l IN VENTO/.

0 m/ muur /aefZZ/Vezaz .WM l 7/ ATTORNEYS Feb. 27, 1968 R K, NEWCOMB 3,370,845

SHEET FEEDING APPARATUS 5 Sheets-Sheet 2 Filed Sept.

4W Z j Z .j 2E ATTORNEYS' R. K.V NEWCOMB SHEET FEBDING APPARATUS Feb. l27, 1968 3 Shams-SheetI 3 Filed Sept. '7, 1965 INVENTOR.

mw hh fw," l M/h/J I YATTORA/m/S United States Patent Utilice Patented F eb. 27, 1968 3,370,845 SHEET FEEDING APPARATUS Robert K. Newcomb, Bound Brook, NJ., assignor to General Binding Corporation, Northbrook, Ill., a corporation of Illinois Filed Sept. 7, 1965, Ser. No. 485,220 11 Claims. (Cl. 271-26) ABSTRACT F THE DISCLOSURE A sheet feeding mechanism for transporting the top sheet of a stack of sheets from a first position to a laterally removed position, including air means for separating the topmost sheet from the remainder of the stack and a mechanical linkage device moving a sheet lifting suction cup vertically and then horizontally, and conversely to successively feed sheets from the stack.

The present invention relates to apparatus for feeding sheet material and is, more particularly, concerned with the provision of a new and improved apparatus for transporting sheet materials from a stack to the inlet mechanism of a sheet processing apparatus.

In the handling of sheet materials, such as, for example, paper, it has been considered necessary to provide means for transferring a single sheet of the material from a stack of identical sheets, to processing apparatus, such as for example a printing press or the like. It has been found over the years that paper is a particularly difficult material to successfully uniformly feed on a sheet by sheet basis. In situations where the passage of more than one sheet by the feeding mechanism is cause for rejecting the processed sheet, the inconvenience and expense of an inaccurate feeding mechanism becomes extremely great. Accordingly, apparatus for successfully feeding one, and one only, sheet at a time from a stack of sheets has assumed great importance. While I am, of course, aware that sheet feeding devices of various sorts and descriptions have been constructed and sold in the prior art, the feeding system of the present invention is extremely simple in construction and operation, employs relatively inexpensive components, and is essentially fool-proof in operation.

In accordance with the principles of the present invention, a sheet feeding mechanism is provided for lifting a sheet from a stack of sheets, positively separatng the sheet from the sheets therebelow, and advancng the forward edge of the sheet into guide rollers or other inlet sheet controlling means. In effecting this, the top sheet of the stack is lifted adjacent its rearmost edge by a plurality of suction cups. Upon the initial vertical motion of the rear of the sheet of paper, a positive air blast is provided beneath the sheet for separating sheets immediately below the top sheet from the top sheet. Immediately following the vertical lifting of the rearmost edge of the sheet, and the application of an air blast which acts to suspend the sheet in mid-air, the suction cups are moved forwardly toward the inlet mechanism depositing the forward edge of the sheet into the inlet rolls or the like. Accordingly, the sheet-moving suction cups are provided with a progressive vertical and then forward mechanical movement, during which movement the application of an air blast to the sheet is likewise controlled. This combination motion is successfully achieved in accordance with the principles of the present invention in a relatively inexpensive, completely reliable manner.

In order to provide satisfactory suction cup motion along a rather complex path without the application of complicated mechanical equipment, I have provided a combination reciprocal and parallelogram linkage. Re-

ciprocal motor lmeans is provided for initially moving the forward edge of a parallelogram in a generally horizontal plane in a manner such that the trailing edge of the parallelogram is vertically moved. Additional motor means is provided for physically moving both the forward and trailing edges of the parallelogram in a horizontal plane to provide a subsequent substantially horizontal movement. These mechanical motions, coupled with a control for the application of air under pressure, and vacuum, have provided a unique sheet feed system.

It is, accordingly, an object of the present invention to provide a simplified sheet feed system.

Still a further object of my invention is to provide an improved system for separating the topmost sheet of material from a stack of such sheets and delivering such topmost sheet only to another apparatus.

A feature of the invention resides in the provision of a parallelogram linkage actuatable as a whole and in part by simple means.

Another feature of the present invention is the utilization of simple time-delay means in air pressure lines for providing a vertical lifting and laterally sideways cornbination feed motion.

Still another feature of the present invention is to provide a sheet feed mechanism automatically operable to provide efficient sheet pickup over a wide range of sheet pile height with a minimum of expense.

Still other and further objects and featuresof the -present invention will at once become apparent to those skilled in the art from a consideration of the attached drawings and specification wherein one embodiment of my invention is shown by way of illustration only, and wherein:

FIGURE 1 is side-elevational view of a sheet feed mechanism constructed in accordance with the principles of the present invention:

FIGURE 2 is a plan view of the apparatus illustrated in FIGURE 1; and

FIGURE 3 is a diagrammatic illustration of the pneumatic and vacuum system employed in the apparatus of the present invention.

As shown on the drawings:

The sheet feed apparatus construction may readily be seen from a consideration of FIGURES 1 and 2. As there shown, a rotating feed roll 10 is rotatable in a clockwise direction as viewed in FIGURE 1 to pull sheets fed from the left thereof into machinery at the right. A plurality of spherical balls 11 are carried in ball sockets 12 secured to the frame 13 supporting the roll 10. The balls 11 rest upon the sheet 15 as it passes between the roll 10 and the balls 11. The balls 11 act to hold the sheet against the roll 10 and, accordingly, to provide a substantially positive grip contact between the sheet 15 and the pull roll 10. It will, of course, be apparent to those skilled in the art that any number of dilerent apparatus inlet feed mechanisms may be employed with the sheet feed apparatus of the present invention. The fundamental requirement is, only, that mechanism be provided, as in the case shown, for gripping a sheet as it is moved horizontally toward the feeding rolls, and moving the sheet to an internal process station of the machine. The embodiment illustrated has proven acceptable for feed purposes and, further, is particularly well adapted to the mechanical sheet feeding mechanism about to be described.

It is desired that the apparatus be constructed to feed the topmost sheet 16 of material, such as for example paper, from a stack of such sheet materials indicated at 17. The stack 17 is kept substantially peripherally confined in an even stack. Air from a source under pressure is directed against the side of the stack 17 by way of air jets 18 and 19 the purpose of which will be more fully set forth below. Additionally, a relatively light weight readily overpowered spring 20 is provided for maintaining the top sheet 16 properly in position on the stack 17 until selected. It will be noted that the spring 20 is preferably relatively soft and flexible and is not intended as a device for strongly gripping the top sheet 16. Instead, it is intended only that a relatively small amount of holding force be applied to the top sheet 16 in a manner readily overpowered upon the application of eans for removing the top sheet.

Apparatus for moving the top sheet 16 from the pile 17 is provided in accordance with the present invention. This apparatus comprises a pair of longitudinally, substantially 'vertically extending cross-pieces, or wall members 21 and 22. The members 21 and 22 are connected to each other by parallelogram links 23 and 24 which are connected to the cross-pieces 21 and 22 by means of Y pivots 25, 26, 27 and 28. As a result of the utilization of cross-pieces 21 and 22 with parallelogram links 23 and 24, relative movement between the pieces 21 and 22 is controlled such that they remain substantially vertical at all times. Cross-piece 22 is reciprocably mounted in horizontal plane by way of a pair of reciprocal motor shafts 30, 31 supported in sliding bearings 32 and 33 respectively. The shafts 36 and 31 pass slidably through a generally vertically disposed plate 35. The plate 35 is connected to links 24 by way of a pair of links 29 pivotally connected at pivots 36 to plate 35 and pivots 37 to links 24.

With the above mechanical linkage arrangement, it will be seen that if the cross-piece 22 is moved toward the right as viewed in FIGURE 1 when cross-piece 21 is in some manner restrained against movement toward the right, then the parallelogram linkage will require that the cross-piece 21 entirely move generally vertically in the direction of arrow 4G. Upward movement of the crosspiece 21 is terminated by contact of vertically extending adjusting screws 41 which contact the bottom of plate 35. Continued movement of the cross-piece 22 toward the right requires, at this point, that the plate 35 and the cross-piece 21 move toward the right. This movement is permitted by the slide bearings 32, 33 with the result that the parts assume the dot-dash line position in FIGURE l. The result is, accordingly, that suction cups 45 carried by cross-piece 46 secured to the cross-piece 21 are moved first upwardly and then to the right toward the feed pull roll carrying a selected sheet 15 into the nip between the roll 16 and the balls 11. Upon completion of this motion, uid power is applied in the opposite direction to 'the piston rods 30, 31 tending to move crosspiece -22 toward the left as viewed in FIGURE 1. Simultaneously uid power is applied to the plate 35 by means of piston rod 48 slidably' carried in sleeve bearing 49 and secured to plate 35. In view of this simultaneous motion of the rods 30, 31 and 48, cross-pieces 21 and 22 simultaneously move toward the left, causing the suction cups 45 to move toward the left without initially being lowered. Upon interception of the cross-piece 21 and the plate 35, however, by vertical abutments 50, further left-hand movement of cross-piece 21 and plate 35 is prevented. Accordingly, the parallelogram links 23, 24 and the pivoted link 29 cause vertically downward sliding motion of the wall 21, upon continued left-hand movement of the rods 30, 31. Accordingly, the suction cups 45 drop vertically downwardly until they contact the top of the pile of sheets 17. In this connection it will be observed that continued downward movement of crosspiece 21 is limited only by the fact that such continued movement will cause pallelogram links 23, 24 ultimately to contact each other and lock against further movement. When this locking ocurs, further movement of cups 45 downwardly cannot occur. This downward position controls the maximum depth of reach of the suc- Vtion cups 45 and hence, the lowest permissible top of complish the motions above described is provided,in a preferred embodiment of the invention, in a manner illustrated in diagrammatic form in FIGURE 3. As there shown, piston rods 30, 31 and 48 are actuated, respectively, by pneumatic motors 30'a, 31a and 48a, respectively. As illustrated, motors 30a and 31a are two-way motors which move the piston rods 30, 31 toward the right upon the'application of positive air under pressure toline 51, coupled with simultaneously exhaustion of air via line 52. Conversely, movement of the piston rods 30, 31 toward the left is accomplished by the pressurization of line 52 and the depressurization of line 51. Movement of piston rod 48 to the left is accomplished by pressurization of 52 coupled with venting of the chamber 4812 to atmosphere.

As above described, it is desired that the piston rod 48 move toward the right with resistance so that it, in effect, trails the movement of piston rods 30, 31. This is accomplished by providing a restriction in line 52, as at 53, in the form of a valve which permits flow of pressurized air to motor 48a via conduit 52a without restriction but permits retrograde movement of the air from the motor 48a via conduit 52 and valve 53 only by way of a restriction in valve 53. Accordingly, motion of the rod 48 is delayed, thereby causing cross-piece 21 to rise vertically prie-r to any right-hand or horizontal movement thereof, all as above described. It may be observed that restraint of the rod 48 in its movement toward the right may sirnilarly be accomplished by providing a restrictive vent to the chamber 48h permitting the ingress of air into the chamber 48b only at a slow rate while providing unrestricted egress.

Valve 54 comprises a four-way valve of conventional form, such as for example a valve commonly marketed under the trade name Humphrey Four-Way Valve. Such a valve is capable of conventional electrical control to connect an air pressure source 55 selectively to conduits 51 and 52 while simultaneously venting the unselected conduit to a low pressure exhaust or sump 56. Thus, when valve 54 acts to connect source 55 to conduit 51, it simultaneously vents conduit 52 to atmosphere via line 56 and, conversely, when valve 54 connectssource 55 to conduit 52, it vents conduit 51 to atmosphere via conduit 56. As a result of the above arrangement, the mechanical movements of the suction cups 45'are controlled in the manner described. Y

Simultaneously with the pneumatic actuation of the suction cups 45, vacuum and air under positive pressure are selectively applied to the cups. During the time that conduit 51 is pressurized and the rods 30, 31 are being moved toward the right, air under pressure is permitted Vto pass one-way check valve 57 and line filter 58 to a solenoid valve 59. Valve 59 is maintained in a closed condition until the suction cups reach their` right-hand position and the top sheet of paper or the like is well Within the .feed mechanism 10, 11.`At such time, a switch, not shown, which is preferably position-responsive, for example to the position of cross-piece 22 into its righthand condition shown in FIGURE '1, is closed to open valve 59. Upon energization of valve 59, air under pressure is applied to suction cups 45 via conduit 60 and valve 61. Upon pressurization of Vconduit 52, however, and movement of the rods 30, 31 toward the left, with resultant movement of cross-piece 22 toward the left, the position-responsive switch controlling solenoid is actuated to close valve 59 by deenergizing its control solenoid and to energize solenoid valve to connect a source of vacuum 62 to the suction cups by way of conduit 60.v

In addition to the alternate positive air pressure and vacuum applied to the suction cups 45, air under pressure selectively iows through jets 18 and 19. Jet `19 provides a iiow of pressurized air toward the right which blows beneath and floats selected sheet 15 after it has -been lifted from the top of the stack 17. This blowing air effectively separates any sheets that have remained attached to the top sheet held to the suction cups 45 by vacuum. Jet 18 provides a vertical fan of air against the left-hand edge of the stack 17 aiding in keeping the sheets rifl'led for easy separation. In actual practice, air is selectively directed from jets 18, 19 under the control of an air 4piloted valve 63 which directs air from a source 55 to jets 18 or 19 depending upon the air pressure in conduit 64. Thus, during pressurization of the cups 45 by positive pressure in line 51, the bottom jets 18 are activated. Upon connection of the cups 45 to a source of vacuum'via conduit62, however, the pressure in conduit 64 drops connecting jets 19 to the source of air under pressure 55 to provide a separating jet for floating the top sheet away from the remainder of the stack while the sheet is gripped by the suction cups 45. Valve 61 comprises a one-way restriction in the conduit 60 permitting a rapid build-up of pressure in the line 64 upon the application of pressure to the suction cups via line 51 and relatively slowly releasing such air under pressure by way of the suction cups 4S. At the same time, the application of vacuum to the line 64 is rendered gradual by the restriction valve 61.

It will thus be seen that I have developed a very simple mechanical linkage actuated by power motors movable only in the horizontal "direction, to provide both horizontal and vertical movements of the top sheet of a stack of sheet material. Movement of the top sheet is automatically effected and complete separation of the sheet from the stack is automatically positively accomplished by means of an air jet. I have found that the system above described has provided an extremely inexpensive and yet highly efficient automatic feed for sheet material, particularly of paper sheet material. I am, of course, aware that variations and modifications may be made without departing from the scope of the novel concepts of the present invention and it is, accordingly, my intention that the scope of the invention be limited solely by that of the hereinafter appended claims.

I claim as my invention:

1. In combination in a sheet feed mechanism for transferring a sheet from a first position to a laterally and vertically spaced second position, a suction cup, means applying a vacuum to said cup, horizontally movable motor means, mechanical linkage means connected to said cup and said motor means initially lifting said cup from a position in contact with said sheet in its first position and then moving said cup laterally toward said second position, and means applying air under pressure to said suction cup to release said sheet, said linkage means comprising a first member carrying said suction cup, a second member vertically and laterally spaced from said first member in the direction of said second position, rigid link means pivotally connecting said first and second members, pivot means pivotally connected to and supporting said link means between its pivot connections with said first and second members, reciprocal means connecting said horizontally movable motor means with said second member, and means controlling the position of said pivot means to control movement of said first member.

2. In combination in a sheet feed mechanism for transferring a sheet from a first position to a laterally and vertically spaced second position, a suction cup, means applying a source of vacuum to said cup, first and second horizontally movable motor means, and mechanical linkage means interconnected to said cup and said motor means initially lifting said cup from a position in contact with said sheet in its first position and then moving said cup laterally toward said second position, and means applying air under pressure to said suction cup adjacent said second position, said mechanical linkage means comprising a first member connected to said suction cup, a second member positioned vertically and laterally spaced from said first member in the direction of said second position, means connecting said first horizontally movable motor means to said second member for actuation of said second member in opposite directions to and from said first and second positions respectively, a third member horizontally slidable and positioned immediately above said first member, a first link pivotally connected to said second member and said first member, a second rigid link means pivotally connected to said third member and to said first link whereby movement of said second member toward said second position causes first member to move vertically upwardly into contact with said third member and further movement of said second member toward said second position causes said third member to move toward said second position therewith, said third member being connected for actuation in the direction from said second position to said rst position by said second motor means.

3. In combination in a sheet feed mechanism for transferring a sheet from a first position to a laterally and vertically spaced second position, a suction cup, means applying a source of vacuum to said cup, first and second horizontally movable motor means, and mechanical linkage means interconnected to said cup and said motor means initially lifting said cup from a position in contact with said sheet in its first position and then moving said cup laterally toward said second position, and means releasing the vacuum from said suction cup adjacent said second position, said mechanical linkage means comprising a first member connected to said suction cup, a second member' in the direction of said second position, means connecting said first horizontally movable motor means to said second member for actuation of said second member in opposite directions to and from said first and second positions respectively, a third member horizontally slidable and positioned immediately above said first member, a first link pivotally connected to said second member and said first member, a second rigid link means pivotally connected to said third member and to said first link whereby movement of said second member toward siad second position causes the first member to move vertically upwardly into contact with said third member and further movement of said second member toward said second position causes said third member to move toward said second position therewith, said third member being connected for actuation in the direction from said second position to said first position by said second motor means, and a third rigid link connecting said first and second members at points spaced substantially equally from the respective points of connection of said first link with said first and second members whereby said first and second members and said first and third links comprise substantially a parallelogram requiring movement of said first and second members in an upright condition.

4. The construction in accordance with claim 2 wherein the length of said second link equals substantially onehalf the length of said first link and is pivotally connected at the mid-point of said first link.

5. The construction in accordance with claim 3 wherein the length of said second link equals substantially onehalt' the length of said first link and is pivotally connected at the mid-point of said first link.

6. The construction of claim 2 wherein means is provided retarding movement of said third member toward said second position whereby said third member moves toward said second position under the inuence of said first motor means and said linkage.

7. The construction of claim 3 wherein means is provided retarding movement of said third member toward said second position whereby said third member moves toward said second position under the influence of said first motor -means and said linkage.

8. Apparatus constructed in accordance with the provisions of claim 6 including control means providing energization of said first and second motor means from said second position toward said first position simultaneously.

7 9. Sheet feed apparatus constructed in accordance with the provisions of claim 6 wherein abutment means are positioned to intercept said first member upon movement of said first member to said rst position from said second position and prevent further ymovement of said rst member in that direction causing vertically downward movement of said suction cup.

1G. The construction in accordance with claim 2 including four-way valve means for directing air under pressure lto said first movable motor means to move said second member toward said second position and alternatively to energize said rst and second motor means Vto move said rst and second members toward said rst position.

11. The constructionpin accordance with claim 10 including position-responsive switch means for actuating 15 said four-way valve in response to the position of said References Cited UNITED STATES PATENTS 949,850 2/ 1910 Smith. 2,566,175 8/1951 Danielsson 271--26 2,812,061 11/1957 Pfister 271--26 X 3,079,147 2/1963 Childs L 27,1-26 3,199,863 S/1965 Muller i 271-206 Y EDWARD A. SROKA, Primary Examiner.

M. HENSON WOOD, J R., Examiner.

I. M. ERLICH, Assistant Examiner.

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