US3283628A - Device for feeding band material - Google Patents

Description

Nov. 8, 1966 s. A. AxLlD ETAL DEVICE FOR FEEDING BAND MATERIAL 5 Sheets-Sheet 1 Filed May l0, 1965 A sa s el.

Nov. 8, 1966 s. A. AxLlD ETAL DEVICE FOR FEEDING BAND MATERIAL 5 Sheets-Sheet 2 Filed May l0, 1965 Fig.3

Nov. 8, 1966 s. A. AXLID ETAL. 3,283,628

DEVICE FOR FEEDING BAND MATERIAL Filed May 10, 1965 5 Sheets-Sheet 3 United States Patent O 3,283,628 DEVICE FOR FEEDNG BAND MATERIAL Sven A. Axiid, JakobSberg, Rudolf F. Greiner, Alvsjo, and Gunnar Winkler, Bromma, Sweden, assiguors to Arenco Aktiebolag, Stoclrholm-Vallinghy, Sweden Fiied May 10, 1965, Ser. No. 454,310

Claims priority, application Sweden, May 14, 1964,

3 Claims. (Cl. 553-74) The present invention is an improvement in advancing units for various types of strip material, eg. paper webs. The invention particularly relates to cutting or punching machines for cutting tjhe strip into sheets of equal size, whereby feeding of the strip is carried out at a certain speed in relation to the movement of a knife, punch or the like. The size, and accuracy of size, is determined by the driving speed of the drive arrangement which feeds the strip relatively to the speed of a rotating knife or punch, which driving speed is composed, in a differential, of magnitudes from a gear or the like which, parallel with a variator via the differential, transmits the driving force from an engine to at least one feeding roller.

The problem of feeding strip material to a definite position and in definite lengths is recognized in a number `of industrial fields, for example manufacturers of packeting media, and printing works. The degree of ease in which the problem can be resolved depends on the properties of the strip material, the required accuracy in the fed length and the feeding speed. The importance of high accuracy in the feeding is obvious in most cases. Such is the case, for example, in multicolour printing, where a paper web passes several printing rollers and its position on each r-oll must lie within very close limits. High accuracy in feeding is also required when cutting sheets from a paper web that has been previously printed upon, whereby the printed pattern has a definite position on the sheet.

Feeding units of a more, or less, complex nature, are known from the earlier techniques. Principally it is possible to feed a strip by means of a driven roll which presses against the strip and rotates through a certain angle corresponding to the required length or size. Accuracy, however, is poor with the use of such simple means due to the fact that the strip bends, and, possibly due to the eccentricity in the mounting of the roller or varying slippage between strip and roll. In order to achieve a better result the feeding movement must therefor be corrected in relation to the movement of the knife, punch, etc. In a known arrangement, the driving force is transmitted from a motor to the worm gear of a differential, where one of the two driven shafts is connected to a feeding roll, while the other carries a stepping arrangement, comprising a ratchet wheel attached to the shaft, and a pawl released electrically, said pawl, when in the locking position, prevents the ratchet wheel and the shaft from rotating. The arrangement is driven so that a certain over feeding of the strip material occurs. The position of the fed strip is continuously recorded by means of a control arrangement, and when the position due to overfeeding, exceeds a certain margin, the pawl in the stepping arrangement is released and a portion of the feeding movement supplied from the engine runs out through the ratchet wheel which is thereafter re-locked. While the ratchet wheel is rotating, the feeding of the strip is reduced whereby a correction of the position of the strip relative to a rotating knife, punch etc. is carried out. Corrections are not made for each length fed between two cuts, instead a varying number of lengths are fed between each correction depending upon the magnitude of over-feeding and correction. The

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arrangement now being described usually gives an taccuracy of from one to two millimetres in the feeding lengths. The accuracy here is combined with the magnitude of the correction and this can not be made arbitrarily small since paper of various types or various batches are more or less easy to feed due to the varying friction, stretch etc. and this influences the size of the over-feed.

Large overfeeding requires large correction, and it must always be taken into account that the length of the sheet when cutting, for example, strips havin-g printed patterns, can vary due to poor accuracy when printing, different moisture contents of the paper etc., which is why the correction must be determined in accordance with the outer limits demanded by tihese properties. It is also known to construct feeding units which .give a very high degree of accuracy with respect to the feeding lengths such as i0.l to 0.2 mm. This unit is more complicated, and is expensive to produce. A unit which closely approaches the unit described above can be mentioned as a simple example of such units. If tihe stepping arrangement in this unit is exchanged for a variator driven by a motor, a feeding movement can also be transmitted to the dif-I ferential in this way. The movement of the feeding rolls is composed of two magnitudes, rstly the movement transmitted over the worm drive of the differential, secondly the movement supplied over the variator onto the second input shaft of the differential. The r.p.m. on the output shaft of the variator is adjusted on the variator by a servo motor which in turn can be controlled by an amplifier, the input of which is actuated by a control arrangement which records the position of the strip relative to a knife, punch etc. Displacements in the position of the strip are registered in the amplifier which, when necessary, gives the servo motor a signal for adjusting the number of revolutions of the variator.

The present invention constitutes an improvement of the feeding units known or used at present, and the irnprovement lies in that the simple and robust construction of the stepping arrangement is combined with the accuracy of the servo arrangement. The arrangement according to the invention has at least one feeding roll for a continuous strip material, for example a paper web, which roll is driven by means of a transmission comprising a differential, which is driven from two directions by means of a gear or the like, and a variator, directly connected with a coupling which during short periods can disengage the drive over the variator. The advantage with this arrangement when compared with the described feeding unit having stepping arrangements, is that it is possible to set a suitable over-feed on the variator so that the magnitude of the correction can be held reasonably low and fitting for the section of the strip which i-s being worked upon at that moment. Should a certain section of the strip be easier to feed, the over-feed is reduced by the adjustments on the variator and the correction can be held constantly low. In the subject of the invention the correction is carried out in that said coupling, for a brief period, disengages the drive over the variator and brakes the shaft of the differential connected to the coupling, which means that the feeding of the -strip is reduced for a moment. The arrangement can also be operated so that an underfeeding is effected, whereby the proportions become analogous with the case for over-feeding, with the difference that feeding during the moment of correction increases instead of decreases. The aforesaid advantage of being able to maintain the correction constantly low, naturally implies that the accuracy in the fed lengths is greater with the subject of the invention than with previously known arrangements, and for good accuracy in the pattern printed on the strip it should be possible to keep deviations within approximately 0.5 mm. An advantage is also gained in that the variator and the coupling lie on the same shaft as the differential, since due to this a sequence of machine members is saved, which would otherwise be necessary if the previously known arrangement were to be completed with only a variator and a driving arrangement for the same. Another advantage with the subject of the invention is that no servo motor is inclu-ded in the arrangement which means that it is more reliable in operation than feeding units which have been fitted with such motors.

The invention is described below in connection with the attached drawing of which FIG. 1 shows the mechanical construction of the arrangement according to the invention seen in a vertical projection, FIG. 2 shows the same arrangement in a horizontal projection, FIG. 3 shows a diagrammatic arrangement in perspective with the electrical circuits included in the gure, and FIG. 4 an electric control circuit which is used for setting the number of revolutions of the variator.

As can be seen from FIGS. l and 2, the arrangement comprises a number of machine members which are mounted on a machine frame 1. The strip material 2 is advanced by a feeding roll 3, the shaft 4 of which is mounted in the frame 1, over a table 5 to a rotating knife 6 mounted on a sector which is seated on a shaft 7 mounted in the frame 1. Below the feeding roll 3 is situated another roll 8 journalled on a shaft 9, which is pivotally mounted by means of an arm 11 on another shaft 1Q secured to the frame. Pressure is exerted on this roller by means of a spring 12, one end of which is secured to the arm 11 and the other end in the frame, against the strip material 2 and the feeding roll 3, whereby the friction between said strip and feeding roll increases. rl`he end of the table 5 facing the shaft of the knife 7 is given an edge piece 13 provided with a sharp edge 14 against which the knife 6 operates.

A sprocket wheel 15 is securely attached to the shaft 7, a chain (not shown) transfers a force to said sprocket Wheel 15 from a motor; also not shown. The motor thus drives the knife 6 but also the feeding roll 3 via a transmission which partly comprises gears 16, 17 and 18 and a differential 19, and partly gears 20 and 21, bevellcd drive 22 and 23, a variator 24, a combined electro magnetic coupling and brake 25, 26 respectively and the differential 19. The two gears 16 and 2! are securely attached to the shaft 7 and drive against the gears 17 and 21 respectively. The gear Wheel 17 is mounted on the neck of a shaft 27, which is secured to the frame by means of a bolt 28. The gear wheel 18 is driven from the gear wheel 17, the gear wheel 18 being in a certain transmission ratio to the gear wheel 16. It is this ratio which determines the size of the cut sheets. In order to alter the size of the sheet the gear wheels 16 and 17 are changed for other gears which correspond to the transmission ratio required for said new size. The gear wheel 18 is rotatably mounted on the shaft 4 and is in direct connection with a centre gear wheel 29 `situated in the differential. The gear wheel 21 is securely attached to a shaft 30 which is mounted in the frame and which transmits the force to the bevel gear drive 22, also securely attached to the shaft 30. The force is subsequently transmitted to the shaft 31 due to the fact that the bevel gear drive 22 drives the bevel gear drive 23 which is securely attached to this shaft. From this point the input shaft 33 of the variator 24 is driven via a shaft coupling 32. This variator 4is of conventional design with friction surfaces and adjustable movement transmission members. The transmitted movement in the variator is transferred from the output shaft 34 of the variator to the electro magnetic coupling 25, which has an armature 35 common to the electro magnetic brake 26. The shaft 36 of the coupling mounted in the frame is coupled when the coupling coil 37 is energized, to the shaft 34 due to the fact that the armature 35 is displaced axially towards this shaft. When current is supplied to the braking coil 38, the shaft 36 is coupled to the frame due to the displacement of the armature in another direction. The armature rotates together with the shaft 36, and the intermediary piece 39 is securely connected to the frame. The movement, by means of a worm screw 40 which is securely attached to the shaft 36, is transmitted to the worm wheel 41 of the differential, whereafter the movement, via compensating wheel drive 42 and 43 journalled on the shaft pins 44 and 45, respectively which are securely bolted to the worm wheel 41, is combined with `the movement from the gear wheel 16, 17 and 18, since the drives 42 and 43 drive against the centre gear Wheel 29. The combined movement is transferred via a second centre gear wheel 46, securely attached to the shaft 4, to the feeding roll 3.

The electrical couplings, together with a diagrammatic illustration of the mechanical constructions, are shown'in FIG. 3. As was stated above, the corrections are carried out in the arrangement by disengaging the drive over the variator by means of an electro magnetic coupling and brake. The electro magnetic coupling is energized when its coil is alive, said coil being supplied with current during the time between two corrections. The circuit for this current passes from the positive pole over a relay contact 47 through the coupling coil 37 to the negative pole. When a correction is made, the contact spring 48 changes its position from the relay contact 47 to contact 49, whereby the current to the coupling coil 37 is broken and the brake coil 38 receives the current instead. Thereby the shaft 36 is braked during that period the contact spring abuts the contact 49. The contact spring and the contacts belong to relay 54B which has two relay coils 51 and 52, both of which having one end connected to the minus pole. The supply of current to the coil 51 is carried out over a relay contact 53, belonging to another relay 54, and a relay contact 55 on the relay 50. The coil 52 obtains current over a switch S6 which is controlled by a cam disc 57, securely attached to `the shaft 7. The relay 54 also has two relay coils 58 and 59 of which the first mentioned is included in a circuit comprising a switch 60 which is controlled by a cam disc 61 on the shaft 7, the coil 58 and the output of a thyratron amplifier 62. The circuit over coil 59 is closed over the relay contacts 55 and 63 on the relays 5) and 54 respectively. The input of the amplifier 62 is connected to a photo cell 64 placed adjacent to the strip 2 and sensitive to reflecting light spots 65 on the strip. The lamp 66 illuminates these necks of light, whereby the light is reflected against the photo cell. The signals from the photo cell are amplitied in the amplifier, a thyraton being included in the final stages of the same. The amplified signals prepare the ignition of the thyratron which occurs if a positive voltage enters, at the same time as the signal from the photo cell, the anode of the thyratron from the coil 58 and the switch 60. Ignition of the thyratron means that the coil 58 receives current and that the relay 54 is energized.

The function of the electrical system is as follows. When energized, the relay 50 holds over the coil 51 and the contacts 53 and 55. The self holding implies that the coupling coil 37 lies connected. When the relay 54 is energized the self-holding circuit is broken but relay 50 is held energized by the coil 52 which is kept supplied with current as long as the switch 56 is not influenced. The relay 54V takes self-holding over the coil 59 and the contacts 63 and 55. When the cam of the cam disc 57 inuences the switch 56 the current is broken by the coil 52 and the relay 50 falls, whereby the brake coil 38 is connected and the self-holding for the relay 54 ceases. When the cam of the cam disc has passed the switch, the current is again closed by coil 52, the relay is energized and takes self-holding and the coupling coil 37 is re-connected. This sequence occurs when a correction is made.

When this condition for correction is not fulfilled, which occurs when there is no synchronization between the signal of the photo cell and the positive voltage from the switch 60, the relay 54 is not energized since the thyraton is then not ignited and no current is closed through the coil 58. The self-holding circuit for the relay 50 is not broken, which is why this relay lies closed the whole time and the coupling coil 37 connected. Thus the determination of the position of the strip 2 in relation to the rotating knife 6 is effected by a photo-cell sensing of flecks, marks or the like which are printed or otherwise attached to the strip 2 at a mutual distance equal to the length of the size. Thus, for each length of strip advanced the photo cell is infiuenced once and sends a signal to the amplifier 62. The flecks are also used for a first rough adjustment of the position of the strip relative to the knife. A scale 67 is marked out on the feeding table 5, against which a fieck on the strip is positioned at the same time as two indicators 68 and 69 marked out on the knife and machine frame respectively lie opposite one another. This adjustment is made before a feeding begins, and when the unit is then started the position of the strip coincides relatively close to that of the knife so that a correction of the position according to the above can ybe carried out very quickly and without unnecessary waste of strip material due to a wrong cutting.

In order to facilitate a quick or rapid adjustment of the variator, the arrangement is lprovided with an electric control circuit having an indicator from which the closeness of the corrections can be read, for example how many lengths are fed between two corrections. It is possible, by means of the indicator, to see if the corrections occur, during a machine operation, at the right speed in sequence, that is to say not too close but neit-her to widely spaced. The electrical control circuit can be designed the same as that described in the Swedish specifi-cation 171,687. According to this specification the control circuit comprises a relay arrangement (see FIG. 4) having a plurality of part circuits with 1an input circuit, comprising a condenser 69 for storing an electric .pulse and an output circuit, comprising a relay member 70, a switch 71, the contacts of which are influenced by a rotating cam disc 72 and connect the condenser and relay member in series so that the pulse stored in the condensator energizes the relay member, thereby a corresponding pulse is transmitted to and stored by the -condenser 73 in a subsequent part circuit. The cam disc 72 similarly to another car;` disc 74, which actuates another switch 75, is driven from some rotating shaft in the feeding unit, for example the shaft 7. The control circuit works in the following manner. When a correction according to the above is cartied out in the feeding unit, the relay contact 63 receives a positive potential which, by a lead 76, is rled to the first part circuit in the control circuit. A relay having a relay -coil 77 is activated rand holds over a relay contact 78 ann the switch 75. At the same time a lamp 79 or the like in the indicator is illuminated and the condensator 69 is charged. Holding of the relay is broken when the cam disc 74 activates the swtich 75 and, when the signal on the lead 76 has previously ceased, the lamp 79 is extinguished. The cam disc 72 thereafter activates switch 71 whereby a circuit containing the condenser 69 and the relay member 70 is closed which means that the condenser is discharged through the coil of the relay and the relay is energized. Holding of this relay occurs over another relay contact 80, a relay coil 81 and the current switch 75. At the same time a second lamp 82 is illuminated and the condenser 73 charged. When the cam discs have rotated a further revolution, the sequence of events is repeated in the next part circuit and due to this advance of the original signal on the lead 76, it is possible to see from the lamps how many revolutions the knife shaft 7 has rotated after the latest correction. When a new correction is made, a new advance begins from the first part circuit.

Due to the ability of the arrangement just described to easily control the 'adjustment of over feeding or under feeding of the strip, the technical effect of the invention has been appreciably improved. With certain of previously known feeding units, which lack this control possibility, the adjustment of the position of the strip has at the beginning of a new strip and also during the sequence of operation, taken along time, and the rejection of wrongly cut sheets has been large. However, if the control arrangement shall appear to full advantage, it is required that the feeding unit is provided with an easily operated adjusting member for the rate of feed. In the arrangement according to the invention the fine adjustments are carried out by this rate through the regulation of the number of revolutions `of the variator, which can easily be carried ou-t manually or by a .servo motor. It is clear from the above :description that the lgear 16, 17, 18 and the input shaft 31 of the variator i-s driven from 'the same driving source. A completely similar lrelationship is hereby attained for the feed and the correction independent of the speed of the arrangement. In other, servo controlled feeding units, one often gets a completely different function accuracy depending on the speed of the machine.

The invention has been described above in connection with the embodiment shown on the drawing but a number of modifications wi-thin the scope of the invention are possible. For example the cam disc switch 60 can be arranged so that the contact is broken up on actuation of the cam, whereby the disadvantage of contact rebound is eliminated. The discussed relay functions must then be altered to their inverted functions. It seems also possible to use `wholly electronic switches instead of electromagnetic relays.

What is claimed is:

1. A device for advancing a strip to be clipped into sheets of equal size comprising a knife mounted on a rotatable shaft adapted to be driven by la motor, driving means for advancing the strip relative to the speed of said knife clipping the strip into sheets, whereby the sheet size and size accuracy is determined by the speed at which said driving means is operated, said driving means including at least one feeding roll, a differential connected to the shaft of said feeding roll, first transmission means adapted to transfer a continu-ous driving force from said motor to said differential, second transmission means comprising a variator and a coupling, `which .are connected in series, electromagnetic control means for said coupling; said second transmission 4means connected in parallel with said first transmission means between said motor and said differential whereby the driving speed to said feeding roll is composed of the driving speeds `.of said first and second transmission means, the device also comprising a control arrangement provided with la sensing arrangement sensitive to indicating means on the strip and cam operated contacts and a switch controlled in time with the rotation of said knife; said control arrangement adapted, when signals of said sensin-g arrangement and said switch, respec-tively, lare coincident, to supply current to said electromagnetic control means for uncoupling said coupling upo-n operation of said cam operated contacts controlled by the rotation `of said knife, and after a predetermined period determined by said cam operated contacts to recouple said coupling.

2. A device as claimed in claim 1, wherein said control arrangement includes two electromagnetic relays of which one is excited when the signals of said sensing arrangelment and said switch are coincident, and the other relay is excited by |a coil having two holding cir-cuits of which one circuit is opened by relay contacts provided lon said one relay and the other circuit is opened by said cam operated contacts controlled by the rotation of said knife; the latter of said two relays being 4provided with a pair of lmake and break contacts for controlling current to said electromagnetic control f-or uncoupling said coupling and engaging said coupling.

3. A device for advancing a strip to be clipped into sheets of equal size comprising a knife mounted on a rot-atable shaft adapted to be driven by a motor, driving means for advancing the strip relative to the speed of said knife clipping the strip into sheets, said driving means incoupling, which are connected in series with each other 5 and in lparallel with said first transmission means between said motor and said differential, a control arnangefment provided with a sensing arrangement sensitive to indicating means on the strip and a switch controlled in time with the rotation of said knife; said control arrangement 10 adapted, when signals of said sensing arrangement and said switch, respectively, are coincident, to uncouple said coupling for a period; the device also comprising a counting arrangement, for aiding in controlling the setting of said Variiator to the correct feeding speed for said strip, said counting .arrangement comprising a number of indicators, a stepping means for moving successively a signal received in conjuction with 'an uncoupling of said coupling from one indicator to another upon rotation of said knife to show the number of knife rotations between each uri-coupling operation.

References Cited by the Examiner UNITED STATES PATENTS 2,035,201 3/1936 Smith etal 83-74 X 2,038,452 4/1936 Sharkey et al. 83-74 X 2,830,811 4/1958 P-aul 83-74 X 2,995,968 8/1961 Tomberg 83-74 3,084,579 4/ 1963 Melville 83-74 3,186,273 6/1965 Tomberg 83-74 15 WILLIAM W. DYER, IR., Primary Examiner.

I. M. MEISTER, Assistant Examiner,

Claims (1)

1. A DEVICE FOR ADVANCING A STRIP TO BE CLIPPED INTO SHEETS OF EQUAL SIZE COMPRISING A KNIFE MOUNTED ON A ROTATABLE SHAFT ADAPTED TO BE DRIVEN BY A MOTOR, DRIVING MEANS FOR ADVANCING THE STRIP RELATIVE TO THE SPEED OF SAID KNIFE CLIPPING THE STRIP INTO SHEETS, WHEREBY THE SHEET SIZE AND SIZE ACCURACY IS DETERMINED BY THE SPEED AT WHICH SAID DRIVING MEANS IS OPERATED, SAID DRIVING MEANS INCLUDING AT LEAST ONE FEEDING ROLL, A DIFFERENTIAL CONNECTED TO THE SHAFT OF SAID FEEDING ROLL, FIRST TRANSMISSION MEANS ADATPED TO TRANSFER A CONTINUOUS DRIVING FORCE FROM SAID MOTOR TO SAID DIFFERENTIAL, SECOND TRANSMISSION MEANS COMPRISING A VARIATOR AND A COUPLING, WHICH ARE CONNECTED IN SERIES, ELECTROMAGNETIC CONTROL MEANS FOR SAID COUPLING; SAID SECOND TRANSMISSION MEANS CONNECTED IN PARALLEL WITH SAID FIRST TRANSMISSION MEANS BETWEEN SAID MOTOR AND SAID DIFFERENTIAL WHEREBY THE DRIVING SPEED TO SAID FEEDING ROLL IS COMPOSED OF THE DRIVING SPEEDS OF SAID FIRST AND SECOND TRANSMISSION MEANS, THE DEVICE ALSO COMPRISING A CONTROL ARRANGEMENT PROVIDED WITH A SENSING ARRANGEMENT SENSITIVE TO INDICATING MEANS ON THE STRIP AND CAM OPERATED CONTACTS AND A SWITCH CONTROLLED IN TIME WITH THE ROTATION OF SAID KNIFE; SAID CONTROL ARRANGEMENT ADAPTED, WHEN SIGNALS OF SAID SENSING ARRANGEMENT AND SAID SWITCH, RESPECTIVELY, ARE COINCIDENT, TO SUPPLY CURRENT TO SAID ELECTROMAGNETIC CONTROL MEANS FOR UNCOUPLING SAID COUPLING UPON OPERATION OF SAID CAM OPERATED CONTACTS CONTROLLED BY THE ROTATION OF SAID KNIFE, AND AFTER A PREDETERMINED PERIOD DETERMINED BY SAID CAM OPERATED CONTACTS TO RECOUPLE SAID COUPLING.

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