US3261601A

US3261601A - Sheet pick-up and conveying device

Info

Publication number: US3261601A
Application number: US392448A
Authority: US
Inventors: Schwebel Adolf
Original assignee: Mabeg Maschb Nachf Hen GmbH
Current assignee: Mabeg Maschb Nachf Hen GmbH; MABEG MASCHINENBAU GmbH NACHF HENSE and PLEINES GmbH and CO
Priority date: 1964-08-27
Filing date: 1964-08-27
Publication date: 1966-07-19
Anticipated expiration: 1983-07-19

Description

July 19, 1966 A. SCHWEBEL.

SHEET PICK-UP AND CONVEYING DEVICE 5 Sheets-Sheet 1 Filed Aug. 27, 1964 INVENTOR.

ADOLF SCf/WEBEL BY Haw MMQ/ July 19, 1966 A. SCHWEBEL SHEET PICK-UP AND CONVEYING DEVICE Filed Aug. 27, 1964 5 Sheets-Sheet 2 INVENTOR. ADOLF' SCHWEEEL BY MGM/q, 0W4, W

July 19, 1966 A. SCHWEBEL 3,261,601

SHEET PICK-UP AND CONVEYING DEVICE Filed Aug. 27, 1964 3 Sheets-Sheet 5 INVENTOR. ADOLF' SCHWEBEL BY HM United States Patent 3,261,601 SHEET PICK-UP AND CONVEYING DEVICE Adolf Schwebel, Offenbach (Main), Germany, assignor to Mabeg Maschinenbau G.m.b.H., Nachf. Hense 8; Pleines G.m.b.H. & Co., Offenbach (Main), Germany Filed Aug. 27, 1964, Ser. No. 392,448 11 Claims. (Cl. 27111) The present invention relates to a sheet feeding device for withdrawing successive sheets from a stack or pile of sheets and conveying the withdrawn sheets in the form of a continuously flowing line of overlapping sheets, and more particularly, to a device of this kind in which the sheets are successively withdrawn by sequentially controlled blowing and suction means which move along an endless path in the direction of the sheet transport and a return direction opposite thereto and which, when moving in the return direction, slide under a lifted sheet and press such lifted sheet against transport means continuously rotating in the direction of the sheet transport.

With devices of this kind as heretofore known the top sheet of a stack is lifted at its forward edge by suction means and after having been transported through a predetermined distance is transferred to the next following suction means which, in turn, transfers the sheet to other transport means such as a conveyor table a roller, etc.

Such devices are limited to handling certain sizes and qualities of sheets and have a comparatively low output.

It is an object of the invention to provide a novel and improved sheet-feeding device which is capable of handling practically all sizes and qualities of sheets and which is simple and reliable in construction and operation.

It is also an object of the invention to provide a novel and improved sheet-feeding device of the general kind above referred to which can feed sheets at very high rates of feedmodern printing presses use 30,000 sheets per hour and more-and also at low rates of feed whereby a device according to the invention is useful not only for larger runs but also for small runs, pilot runs, rush jobs, etc.

A further object of the invention is to provide a novel and improved sheet-feeding device of the general kind above referred to which delivers sheets accurately oriented so that they reach, the printing press or another treatment station in the correct position.

The aforementioned object, features and advantages and other objects, features and advantages which will be pointed out hereinafter are attained by providing ahead of the forward edge of a stack or pile of sheets, blowing nozzles for loosening up the sheets in the top layer of the stack and mounting each of the suction and blowing means lengthwise displaceable against spring action in a support. Each support in turn is suspended on suspension means and suitable drive means impart to the suspension means, together with the support means and the suction and blowing means, a motion along a closed path, preferably a circular path. The motion of the suspension means is transmitted to the suction and blowing means by a spring superimposed between the support means and said means and is controlled by the engagement of the support means with stationary camming surfaces and by engagement of the suction and blowing means, preferably by means of rollers on the suction and blowing means, with rotary sheet transport means disposed posterior of the suction means in the direction of the sheet travel. As a result, the path of the suction and blowing means in respect to the top side of the stack diverges partly from that imposed upon the suspension means and is so arranged that suction and blowing means are sequentially moved into and out of engagement with the top surface of the stack to withdraw successive sheets therefrom.

A rotary sheet-deflecting means is preferably provided ad acent to the anterior part of the stack as seen in the direction of the sheet transport to direct successive lifted sheets between the top side of the suction and blowing means and the transport means coacting therewith.

In the accompanying drawing several preferred embodiments of the invention are shown by way of illustration and not by way of limitation.

In the drawing:

FIG. 1 is a diagrammatic elevational view of a sheet pick-up and conveying device according to the invention.

FIG. 2 is a fragmentary sectional view of a modification of the suction and blowing assembly of the device.

FIGS. 3 through 6 show diagrammatically the parts of the suction and blowing assembly in different positions of operation.

FIG. 7 is a fragmentary sectional view of a further modification of the suction and blowing assembly, and

FIG. 8 is a simplified elevational view of the device showing control means therefor.

Referring now to the figures in detail, the suction and blowing assembly of the sheet pick-up and conveying device comprises several suction and blow heads. Three

heads

1, 2 and 3 are shown but it should be understood that a smaller or greater number of heads may be provided. In FIG. 1 two heads and in FIG. 8 one head are shown for clarity of illustration. Each head is supported by and in communication with a

pipe

4, 5 and 6 respectively. The pipes should be visualized as being alternately connected to a suitable supply of suction or pressure air as will be more fully explained hereinafter and are supported by a support structure 7 for each pipe in which the pipes and with it the heads are lengthwise slidable. The pipes and hence the heads are springloaded by means of springs 10 as is shown for pipe 4.

Adjustable nuts 13 retain each pipe in a position such that the heads and, more specifically, the orifices 16 in the heads are at a predetermined distance in reference to the top sheet of a stack or pile 17 when the heads are in the operational position for gripping and lifting the top sheet as will be more fully described hereinafter. The suitable spacing of the orifices 16 in reference to the top layer of the stack is a matter of practical experience and well understood. The lifting and the control of stack 17 as it is being depleted do not constitute part of the invention and are hence not described or illustrated in detail.

To permit adjustment of the angular position of each pipe in reference to its support structure 7, a bracket 18 is provided for each pipe. Each of the brackets mounts a set screw 21 which coacts with parts of the respective support frame to vary the angular position of the pipes and hence of the heads thereon by adjusting the set screws.

The support frames and the suction and blowing assemblies supported thereon as previously described are suspended by suitable suspension means shown as bolts 27 and 28 respectively and 30 and 31 respectively. The two sets of bolts rotate about axes 33a and are driven by drives diagrammatically indicated at 33 and 33b in a well understood manner.

As it is shown in FIG. 1, each support structure further includes a mounting arm 24 and 25 respectively. Each mounting arm is directly linked at one end to the main body of the support structure by the lower bolts 27 and 28 respectively but coacts at the other end with the main body through an interposed loaded spring 34. Each spring presses the respective support structure and with it the respective suction and blowing assembly into coaction with a camming surface 40a of a stationary cam member 40 by means of a cam follower 37 mounted in a protrusion or nose extending from the respective support structure. Each cam member 40 may be adjusted as to its effective height by a suitable conventional adjustment means indicated at 65.

As a result of the coaction between the rollers and the camming surfaces the heads are sequentially moved into the gripping position with the top sheet of stack 17 While the support structures perform a pivotal movement about the respecive suspension bolts 27 and 28 respectively. Head 1 and the associated structural elements which are shown in heavy full lines, are illustrated in the positions in which the head is picking up the uppermost sheet.

As it is evident from the previous description, the paths impressed upon the mounting arms 24 and 25 are distorted due to the action of springs 34 and the movement of rollers 37 along the c-amming surfaces 40a. The paths followed by the heads during the completion of the circular paths by bolts 27 and 28 are indicated by a dash-dotted outline 66. When the heads follow the outline 66 they are sequentially moved downwardly into the gripping position with the uppermost sheet on stack 17. After leaving circular portion 41 of outline 66 they are pressed back against the action of springs 10 while travelling along portion 42 of outline 66. Finally, while travelling along portion 43 they move into engagment with a sheet transport roller 44.

Turning now to FIGS. 3 to 6, sheet II which should be visualized as having been lifted by the head sequentially preceding the head now effecting lifting of the uppermost sheet, is pulled along the top side of the head now in its top position (head 3) by the coaction of this head with a roller 44. To facilitate transport of the sheets between roller 44 and the respective head, a

pressure roller

46, 47 and 48 respectively protrudes from the top side of each head. As it is indicated in FIG. 2 for roller 46, each roller may be supported by a schematically indicated leaf spring 67 which engages a pin 67a slidable in a slot 46a of the roller.

To facilitate guidance of lifted sheets into the positions between roller 44 and the

respective counter roller

46, 47 and 48, a rotary deflecting roller 49 is preferably provided. As it is shown in FIG. 8, this roller is in engagement with a roller 49a which in turn engages roller 44.

Rollers

49 and 49a may be adjustably mounted. There is shown a pivotal support bracket 70, the angular position of which may be varied by .a set screw 70a coacting with an abut member 80 against which it is pressed by a spring 81.

When and while the heads move along the path 66,

pipes

4, and 6 are first connected to a source of suction and then to a source of pressure air. The control of the supplies of suction and pressure air may be effected by suitable control means. Such control means are diagrammatically shown in FIG. 8 as comprising a Maltses cross or Geneva mechanism, including a Maltese cross 73 within which rotates a control sleeve 72. This sleeve has in its outer wall a circumferential channel 74 which, through ports 75, communicates with appropriate slots 73a of the Maltese cross and through a duct 76 with a pipe 77 connectable to a source of pressure air or a suction source by a suitable changover connector. Slots 73a are sequentially engaged with the ends of

pipes

4, 5 and 6 as it is indicated by arrows. The Maltese cross is stepwise driven by a drive mechanism broadly indicated at 78. Suitable cycling means of the kind herein referred to are conventional and do not constitute part of the invention. Accordingly, they are not described or illustrated in detail.

When the head :1 is in the position shown in FIG. 3, that is in a position in which it has just gripped and lifted the forward edge ofa sheet I, suction is made effective in head 1. The sheet I is now moved into the position shown in FIG. 4 whereupon pressure air is supplied to the head. As a result the head will release the gripped sheet which will drop upon the top side of the sequentially following head 2 which in the meantime has moved into a position above the stack and underneath head 1. At the same time the third head 3 has transferred a sheet III to the top side of the head 1 and this sheet is now forwarded to the transport roller 44, the movement of the head being controlled by portion 43 of the path 66, which conveys the sheet to the feed table 50 as part of a. web 45 formed by the overlapping sheets.

To assist in the picking-up and conveying of sheets, an air pipe 51 is provided to which pressure air is suitably supplied and which is divided into two branches 52 and 53. Branch 53 directs a flow of air indicated by an arrow 54 against the sheets in the top portion of stack 17 to loosen up the stack at its side facing the suction and blowing assembly. The second branch 53 directs an air flow 55 against the bottom side of a lifted sheet to facilitate separation of the sheet from the top side of the respective head. A third air flow 56 may be provided to facilitate further the separation of the lifted sheets from the top sides of the heads by directing the air flow toward deflection roller 49.

The rotary deflection roller 49 which is disposed above the suction and blowing assembly engages and bends each lifted sheet so that the same obtains a certain stiffness of its entire length which prevents the lifted forward part of each sheet to drop back into its initial position.

Each of the

heads

1, 2 and 3 is provided with a safety valve to protect against a failure of the suction. As it is shown in FIG. 1 for head 1, the safety valve comprises a valve ball 57 which is urged by a spring 58 away from its seat 59. A vent 60 communicates through a duct 61 with pipe 4 and can also communicate with a bore 61 issuing in the top side of the head.

When a sheet is sucked on by the orifices 16 of head 1, the prevailing suction within duct 61 Will increase and as a result valve ball 57 will be pressed against seat 59 against the action of spring 58, thus preventing the ingress of air through the bore 62 toward the suction orifices 16 of the suction head which would jeopardize the retention of the gripped sheet.

As a result the gripped sheet is safely carried within reach of the sequentially next head to be acted upon by the same. Due to the provision of duct 60 a subatmospheric pressure is obtained in bore 62 which causes the previously lifted and conveyed sheet to be sucked on. The resulting covering of the top side 63 of the head by the sucked-on sheet causes a reduction of the suction within the valve chamber 71 such that spring 58 can now.

lift ball 57. away from its seat.

The safety device as shown in FIG. 7 is particularly suitable when the sheet-feeding device with which the pickup and conveying device coacts is operated comparatively slowly and also when the installation is newly set up for operation, or a pilot run is made. Without the safety device a sheet sucked on by the suction heads may not be sufficiently held by the same, or it may fall off when and while being transported by the

rollers

46, 47 and 48 respectively and transport roller 44.

While the invention has been described in detail with respect to certain now preferred examples and embodiments of the invention, it will be understood by those skilled in the art after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention, and it is intended therefore to cover all such changes and modifications in the appended claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. A device for withdrawing successive sheets from a stack of sheets and conveying said sheets in the form of a continuously flowing line of sheets, said device comprising conduit means for directing a flow of pressure air against one side of the stack to loosen up the sheets in the upper portion of the stack, several suction and blow ing means each including a head and a pipe secured to the head and disposed adjacent to said side of the stack, a support means for each of said suction and blowing means, each of said support means including a support member supporting one of the pipes, lengthwise displaceable in reference to the support member, a first yieldable means urging the suction and blowing means into a predetermined position of displacement, a pair of suspension members for each of said support means to suspend the same, one of the suspension members of each pair being pivotally linked to the respective support member, a second yieldable means interposed between the other suspension member of each pair and the respective support member, drive means coacting with the suspension members of each pair for sequentially moving the suspension members together with the respective support member and the suction and blowing means along a closed path,

a stationarily mounted cam member for each support member, each of said second yieldable means urging the respective support member into engagement with the respective camming member during part of said closed path, and rotary sheet transport means disposed above each of said heads, said transport means being engageable with the top sides of the respective heads to displace the suction and blowing means against the action of said first yieldable means for part of the movements imposed to the same by the movements of said suspension members whereby the heads travel in a closed path diverging from that of the suspension members and causing the heads sequentially to lift one sheet and to press a sheet lifted by an adjacent head against said transport means.

2. A device according to claim 1 wherein each of said support members mounts a roller engaging the respective camming member.

3. A device according to claim 1 and further comprising rotary deflecting means for directing a lifted sheet into a position between the respective transport means and the respective head.

4. A device according to claim 3 and comprising means for adjusting the position of the deflecting means in .refer ence to said heads.

5. A device according to claim 1 wherein a roller protrudes from the top side of each head for coaction with the respective transport means.

6. A device according to claim 5 wherein each of said rollers is yieldably mounted in the respective head.

7. A device according to claim 1 wherein said camming member is adjustable as to its height in reference to the respective support member coacting therewith.

8. A device according to claim 1 and comprising adjustment means for adjusting the angular position of each suction and blowing means in reference to the respective support means.

9. A device according to claim 1 wherein said pressure air conduit means includes an orifice for directing flows of pressure air from beneath upon a lifted sheet to assist in pressing the same against the transport means by the respective head.

10. A device according to claim 1 and further comprising rotary deflecting means for directing a lifted sheet between the respective transport means and the respective head, said pressure air conduit means including a branch conduit for directing a flow of air toward said deflecting means.

11. A device according to claim 1 wherein each of said heads includes a duct communicating with the respective pipe and issuing in the top side of the respective head, and wherein a valve is provided in each of said ducts, said valves being spring-biased into the open position and held in the closed position against the spring action by suction in the respective duct, reduction of said suction by closing of the duct due to a sheet covering the top side of the respective head releasing the valve for opening by spring action.

References Cited by the Examiner UNITED STATES PATENTS 1/1958 Williams 27126 1/1959 Backhouse 27126

Claims

1. A DEVICE FOR WITHDRAWING SUCCESSIVE SHEETS FROM A STACK OF SHEETS AND CONVEYING SAID SHEETS IN THE FORM OF A CONTINUOUSLY FLOWING LINE OF SHEETS, SAID DEVICE COMPRISING CONDUIT MEANS FOR DIRECTING A FLOW OF PRESSURE AIR AGAINST ONE SIDE OF THE STACK TO LOOSEN UP THE SHEETS IN THE UPPER PORTION OF THE STACK, SEVERAL SUCTION AND BLOWING MEANS EACH INCLUDING A HEAD AND A PIPE SECURED TO THE HEAD AND DISPOSED ADJACENT TO SAID SIDE OF THE STACK, A SUPPORT MEANS FOR EACH OF SAID SUCTION AND BLOWING MEANS, EACH OF SAID SUPPORT MEANS INCLUDING A SUPPORT MEMBER SUPPORTING ONE OF THE PIPES, LENGTHWISE DISPLACEABLE IN REFERENCE TO THE SUPPORT MEMBER, A FIRST YIELDABLE MEANS URGING THE SUCTION AND BLOWING MEANS INTO A PREDETERMINED POSITION OF DISPLACEMENT, A PAIR OF SUSPENSION MEMBERS FOR EACH OF SAID SUPPORT MEANS TO SUSPEND THE SAME, ONE OF THE SUSPENSION MEMBERS OF EACH PAIR BEING PIVOTALLY LINKED TO THE RESPECTIVE SUPPORT MEMBER, A SECOND YIELDABLE MEANS INTERPOSED BETWEEN THE OTHER SUSPENSION MEMBER OF EACH PAIR AND THE RESPECTIVE SUPPORT MEMBER, DRIVE MEANS COACTING WITH THE SUSPENSION MEMBERS OF EACH PAIR FOR SEQUENTALLY MOVING THE SUSPENSION MEMBERS TOGETHER WITH THE RESPECTIVE SUPPORT MEMBER AND THE SUCTION AND BLOWING MEANS ALONG A CLOSED PATH, A STATIONARILY MOUNTED CAM MEMBER FOR EACH SUPPORT MEMBER, EACH OF SAID SECOND YIELDABLE MEANS URGING THE RESPECTIVE SUPPORT MEMBER INTO ENGAGEMENT WITH THE RESPECTIVE CAMMING MEMBER DURING PART OF SAID CLOSED PATH, AND ROTARY SHEET TRANSPORT MEANS DISPOSED ABOVE EACH OF SAID HEADS, SAID TRANSPORT MEANS BEING ENGAGEABLE WITH THE TOP SIDES OF THE RESPECTIVE HEADS TO DISPLACE THE SUCTION AND BLOWING MEANS AGAINST THE ACTION OF SAID FIRST YIELDABLE MEANS FOR PART OF THE MOVEMENTS IMPOSED TO THE SAME BY THE MOVEMENTS OF SAID SUSPENSION MEMBERS WHEREBY THE HEADS TRAVEL IN A CLOSED PATH DIVERGING FROM THAT OF THE SUSPENSION MEMBERS AND CAUSING THE HEADS SEQUENTIALLY TO LIFT ONE SHEET AND TO PRESS A SHEET LIFTED BY AN ADJACENT HEAD AGAINST SAID TRANSPORT MEANS.