Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H3/00—Separating articles from piles
  • B65H3/46—Supplementary devices or measures to assist separation or prevent double feed
  • B65H3/48—Air blast acting on edges of, or under, articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H3/00—Separating articles from piles
  • B65H3/08—Separating articles from piles using pneumatic force
  • B65H3/12—Suction bands, belts, or tables moving relatively to the pile
  • B65H3/124—Suction bands or belts
  • B65H3/128—Suction bands or belts separating from the top of pile

Definitions

• the present invention relates to a device for automatically and regularly picking up flat sheets, for example sheets of paper, on a stack of sheets feeding a machine in which flat sheets move one by one, for example an assembly machine.
• Friction devices use constant pressure maintained on the sheet by means of pads or casters.
• the pressure adjustment is delicate, which only allows the treatment of a fairly limited range of sheets and does not allow the treatment of very thin sheets, for example delicate papers.
• the suction and friction devices are not insensitive to variations in the parameters which characterize the sheets to be taken from a pile: physical dimensions, weight and size of the sheets; their humidity, their mutual adhesion, static electricity, these parameters also being randomly variable within the same stack of leaves of the same nature.
• physical dimensions, weight and size of the sheets physical dimensions, weight and size of the sheets; their humidity, their mutual adhesion, static electricity, these parameters also being randomly variable within the same stack of leaves of the same nature.
• a stack of sheets of paper for example, is characterized by various parameters such as dimensions and weight of the sheets, static electricity, humidity, mutual adhesion due to the freshness of the printing ink. These parameters are randomly variable within the same stack of paper of the same kind. This is the cause of problems in the separation of the sheets in the assembly machines, hence the need for pretreatment before going through the machine.
• the present invention provides a solution to this problem and has as its object a device for efficiently fading a stack of sheets placed in the feeding compartment of a machine so as to ensure delivery of the sheets one by one, even in the case where sheets stick to one another or in the case where the upper sheet cannot be taken from the pile of eyelets.
• FIG. 1 is an elevational view, partly in section, of an exemplary embodiment of the invention.
• - Figure 2 is a view along line II-II of Figure 1, with cutaway.
• FIG. 3 is a view along line III-III of Figure 2.
• - ' Figure 4 is a view along line IV-IV of Figure 2.
• FIG. 5 is a block diagram of the control system of the descrambling device according to the invention.
• FIG. 1 there is seen a box for supplying an exemplary assembly machine.
• a sheet pickup device 2 Above a feed table 1 is mounted a sheet pickup device 2.
• the sheet pickup device illustrated by way of example comprises a perforated grill 4 mounted on a frame of the assembly so to be able to move by translation under the action of a drive mechanism comprising in particular the toothed wheels and rollers 5.
• the grid 4 is closed on itself and it has a section 6 which can move above the table 1 in the direction of the ejection area 3.
• a suction means constituted for example by fans 7.
• a deflector 9 mounted above of the ejection area 3 and extending over the entire transverse width of the device advantageously closes the top of the ejection area.
• the relative distance between the lower plane 6 of the grid and the top of the stack of sheets on the feed table is kept constant as the height of the stack of sheets decreases.
• the feed table 1 is for example mounted on a mechanism intended to move it vertically as the height of the stack of sheets decreases so as to maintain the top of the stack at a constant distance from the section of grid 6.
• the sheet picking device could be mounted so as to be itself displaced relative to the feed table 1 which would be fixed.
• the simplicity and compactness of the sheet picking device described above which includes neither su ⁇ cettes, rollers, or skids, make it a particularly advantageous and reliable element or module for integrated machines of modular construction.
• the control of all the organs can be integrated into a general automatic control programming of the device under the surveillance of detection elements controlled by a processor which can be incorporated into the machine.
• Detection elements are provided for monitoring the operation of the sheet picking device.
• a detection element is used to detect the presence or absence of sheets on the feed table 1.
• detection elements can be arranged with predetermined spacings so as to be able to detect the format of the sheets stacked on the feed table 1 and order the commissioning of the desired number of fans 7 and a detection element is used to control the passage of the sheets in the ejection area 3.
• the deflashing device is designated as a whole at 10. It comprises an air flow generator constituted, by way of example, by a turbine 15 extending along the bottom wall 18 of the feed table 1, under the ejection area 3, and this turbine 15 is associated with deflector means arranged so as to direct at least one air flow turbulent practically on the front side of the upper sheets of the stack of sheets 100 as will be seen.
• the box bottom wall 18 has several openings 19; these are clearly visible in FIG. 2. These openings 19 are normally closed by a shutter formed by a valve 21 mounted so as to be able to pivot around an axis 22 fixed at its ends to the frame of the machine. The tilting of the valve 21 takes place by means of a connecting rod 27 mounted at one end of the valve 21 and driven by an electromagnet 16 as shown in the view of FIG. 3.
• valves 23 and 25 whose role will be described below. These upper valves are mounted so that they can pivot around the axes 24 and 26 fixed to the frame of the machine.
• the valves 23 and 25 are actioned by connecting rods 28 and 29 mounted at one end of the valves and driven by an electromagnet 17 as shown in the view of FIG. 4.
• the descaling device 10 is controlled by a control processor which can be the general control processor of the machine.
• the processor cooperates with a detection device arranged to permanently monitor the presence of the sheets in the free space 8 in the vicinity of the grid section 6 and to detect any operating anomaly on the grill. : absence of sheet, presence of several sheets glued to each other, crumpled or folded sheet, sheet of different thickness or print, etc.
• the detection device is a thickness detector mounted and arranged for monitoring 1st permanently the thickness of material lying in front of the grid section 6 of the sheet pickup device 2.
• the thickness detector consists of a photoelectric cell 11 responding to a light beam generated by a source 12.
• the detector cell 11 produces an electrical signal which is a function of the thickness of the material intercepting the light beam at an always identical location.
• the control system of the descrambling device according to the invention is represented by the block diagram of FIG. 5.
• the control unit 14 of the microprocessor receives the detection signal D generated by the detector.
• the microprocessor is organized so that the control unit 14 produces a control signal for one or the other of the electromagnets 16 and 17 which control the deflector means according to the value of the detection signal D relative to the values of reference RI and R2.
• the detection signal D is included between the reference signals RI and R2 and the microprocessor does not command any correction.
• the valves 21, 23 and 25 are then held in their closed position as shown in Figure 1 and the turbine 15 is stopped.
• the sheet driven by the grid 6 is then routed towards the ejection area 3.
• the sheet in question identified as corresponding to the reference value, then moves to a detection cell located downstream of a pressure member made up of the rollers 31 and 32 ; the roller 31 is in continuous rotation and the roller 32 is mounted to be lifted under the control of an electromagnet (not shown) so as to pinch the ejected sheet and cause it to advance towards the output members.
• the detection cell 11 produces a signal D of value greater than the reference signal R2 and the microprocessor 14 produces a first signal of command CDl to excite the electromagnet 16 driving the lower valve 21 in order to move it downwards and gradually bring it into its open position illustrated in FIG. 6 while the turbine 15 is placed working.
• the valve drive mechanism 21 In Figure 6 is not shown the valve drive mechanism 21.
• the air flow generated by the turbine 15 is guided by the channel A towards the openings 19 and is thus directed on the front side of the stack of leaves 100.
• the leaves then rise in éven ⁇ tail and the upper sheet 101 is sucked against the grid 6 while the other leaves fall on the stack 100 by the air which creeps between the upper sheet and the sheet next.
• the device is restored to the idle state as soon as the detection cell 11 detects the presence of a sheet 101 in its detection field. As long as it meets the required conditions, this sheet is then drawn towards the ejection area 3.
• the detection signal D produced by the cell 11 is less than the reference signal Ri and the microprocessor 14 produces a second control signal CD2 to excite the electromagnet 17 which drives the upper valves 23 and 25 in order to place them in the positions shown in FIG. 7.
• the mechanism for driving the valves 23 and 25 n is not shown.
• the air flow generated by the turbine 15 is then directed through the channel B towards the ejection area 3 and it is thus directed towards the front edge of the sheets located in the detection field of the cell 11.
• the sheets vibrate and the air flow B creeps between the sheets so that the upper sheet 101 is sucked against the grid 6 while the other sheets are folded over the stack of sheets 100.
• the device is restored to the resting state as soon as the detection cell 11 detects the presence of the single sheet 101 in its detection field and provided that it meets the required conditions, this sheet is then drawn towards the area d ejection 3.
• the de-scaling device ensures the removal of sheets one by one. Any anomaly in the removal of sheets is identified inside the system without the sheet being moved from its initial pile. A sheet is only delivered to the ejection area 3 when it meets the required conditions, which considerably reduces waste and operator intervention.
• the system automatically adjusts its rate according to the quality of the sheets to be treated. It makes it possible to reach high rates at the exit of the box in good conditions. Finally it makes it possible to detect a sheet which is not of the same impression, a sheet of different thickness, a crumpled or folded sheet.
• the range of papers that can be treated is very wide, for example from 10 grams to 300 grams, or even more in some cases.
• the descaling device according to the invention can be combined with a device for picking up any sheets, for example a device for picking up sheets with common suction.
• a device for picking up any sheets for example a device for picking up sheets with common suction.
• the combination of the de-scaling device according to the invention with a suction sheet pick-up device as described in the foregoing and illustrated by way of example in the accompanying drawings is particularly advantageous by the optimal result which results in terms of efficiency and throughput.
• This arrangement according to the invention made it possible to produce a flow rate of the order of 130 sheets per minute with a feed box.
• the advantages of the device according to the invention are particularly attractive for feeding a collator comprising several sheets feeding boxes.
• the regular flow of rigorously controlled sheets ensures perfect superposition of the sheets in the assembly system thanks to the synchronization of the control of the pressing members 31 and 32 of each box.
• the control pulses successively actuate the pressing members of each box so as to advance the sheets successively towards a conveyor belt 33 circulating on the cylinders 34, 35 and 36.
• the sheets delivered by a feed box are advantageously pressed between the carpet 33 and a carpet 37 which rolls on the cylinders 38 and 39.
• the carpet 37 can extend over the entire height of the assembly machine.
• the sheets delivered by any feeding box are superimposed on the sheets delivered by the upper feeding boxes and the bundle of superimposed sheets, pressed between a mat 33 and the mat 37, is brought to the area of ejecting the collator.
• This programmed arrangement makes it possible to continuously control the operation of the sheet picking device and to check in particular the nature of each sheet taken from the top of the stack so as to immediately detect any anomaly before transfer to the ejection area and automatically stop the device to allow the anomaly to be remedied, then restart the machine. Reliability and efficiency of the automation are improved in an optimal manner.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Sheets, Magazines, And Separation Thereof (AREA)
• Controlling Sheets Or Webs (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=8203278

Family Applications (2)

Family Applications After (1)

Country Status (6)

Families Citing this family (14)

Family Cites Families (10)

• 1989
  • 1989-03-17 DE DE68915457T patent/DE68915457T2/de not_active Expired - Fee Related
  • 1989-03-17 US US07/768,400 patent/US5328165A/en not_active Expired - Fee Related
  • 1989-03-17 WO PCT/BE1989/000012 patent/WO1990011240A1/fr not_active Application Discontinuation
  • 1989-03-17 AT AT8989870041T patent/ATE105668T1/de not_active IP Right Cessation
  • 1989-03-17 EP EP89903067A patent/EP0470951A1/de active Pending
  • 1989-03-17 ES ES89870041T patent/ES2049845T3/es not_active Expired - Lifetime
  • 1989-03-17 EP EP89870041A patent/EP0387476B1/de not_active Expired - Lifetime

Non-Patent Citations (1)

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