US 3673418 A
The strip material which is fed intermittently in desired feed lengths is provided with register marks at feed length intervals and photoelectric means continuously scan the strip to detect the marks and effect adjustment of the feed rolls either forwardly or rearwardly through the brake mechanism so as obtain the desired accurate registration of the marks. The photoelectric means produce electric signals as the marks are scanned and said electric signals are passed by shutter means only in the event the mark is detected in either the lead or in the lag zones. The electric signals thus passed are caused to produce electric pulses which are delivered to an electric motor having driving relation with the brake mechanism.
Claims available in
Description (OCR text may contain errors)
United States Patent Wiig [451 June 27, 1972  AUTOMATIC REGISTERDIG APPARATUS  Inventor: Chester M. Wiig, Lincolnwood, 111.
F. J. Littell Machine Company, Chicago, 111.
221 Filed: Sept. 14, 1970 2 1 Appl.No.: 71,994
 US. Cl ..t .i ..250/219 DR, 226/27  Int. Cl. ..G0ln 21/30  Field otSeai-ch .250/205,208,219FT,219D, 250/219 DC, 219 DD, 219 DR, 220, 222, 237;
 References Cited UNITED STATES PATENTS 3,025,740 3/1962 Sorkin ..250/219 DR 2,348,862 5/1944 Sorkin ..250/219DR 3,027,462 3/1962 Helmes ..250/208 Primary Examiner-James W. Lawrence Assistant Examiner-D. C. Nelms Attorney-Russell H. Clark 57 ABSTRACT The strip material which is fed intermittently in desired feed lengths is provided with register marks at feed length intervals and photoelectric means continuously scan the strip to detect the marks and effect adjustment of the feed rolls either forwardly or rearwardly through the brake mechanism so as obtain the desired accurate registration of the marks. The
photoelectric means produce electric signals as the marks are scanned and said electric signals are passed by shutter means only in the event the mark is detected in either the lead or in the lag zones. The electric signals thus passed are caused to produce electric pulses which are delivered to an electric motor having driving relation with the brake mechanism.
5 Clains, 13 Drawing Figures PATENTEDJum I972 SHEET 5 BF 5 1W) nu Z d U WT)! AUTOMATIC REGISTERING APPARATUS The invention relates to automatic registering mechanism and has reference in particular to photoelectric means for detecting register marks on strip material, which is being fed intermittently in desired feed lengths, and for adjusting the feed rolls through the brake mechanism for obtaining the desired accurate registration of the marks.
The invention has application to presses for punching, stamping or cutting strip material which is advanced by feed rolls that are driven intermittently. The feed rolls operate in the normal manner to produce a fixed feed length at each stroke of the press. Registering marks are applied to the strip material in order to maintain a degree of accuracy in the operation of the press and these marks are detected by photoelectric means in the event the marks advance beyond a lead zone or in the event the marks lag as regards a lag zone. If the register mark falls short of the required location a selector switch will pulse an electric motor in a forward direction to move the brake disc structure in the same direction and advance the feed rolls for a relatively small fraction of an inch measured in thousands for each pulse of the motor. This correction of the feed rolls through the brake structure is timed to occur immediately after the feeding cycle is completed so that the movement of the brake will override the drive housing and cause the register marks to advance.
In the event the register mark is detected beyond the desired location, the selector switch will pulse the motor in the opposite direction. The brake structure cannot drive the feed rolls backwards during the feed cycle, but at the end of the feeding period, the drive housing is rotating in a reverse direction so that the brake structure can cause the feed rolls to reverse, thereby causing the register mark to be moved back.
In view of the foregoing an object of the invention resides in the provision of photoelectric means including a scanner and a selector switch for properly registering the marks applied to intermittently fed strip material for the purpose, and wherein an electric motor will be pulsed to move the brake structure for either advancing or retarding the feed rolls thereby initiating a correction should the selector switch call for the same.
With these and other objects in view, the invention may consist of certain novel features of construction and operation as will be more fully described and particularly pointed out in the specification, drawings, and claims.
In the drawings which illustrate an embodiment of the invention and wherein like reference characters are used to designate like parts;
FIG. 1 is a front elevational view showing the selector switch of the registering mechanism in direct driving relation with the main operating shaft of the stamping or cutting press;
FIG. 2 is a sectional view of the brake mechanism and which also shows the gear drive to theupper and lower feed rolls of the press which feed the strip material;
FIG. 3 is a front elevational view of the brake mechanism as shown in FIG. 2, the parts of the view in section show the chain and worm drive from the pulsed motor to the brake structure;
FIG. 4 is a front elevational view of the selector switch of the registering mechanism with the cover removed;
FIG. 5 is a vertical sectional view of the selector switch taken substantially along line 5-5 of FIG. 4;
FIG. 6 is a front elevational view of the selector switch with cover removed similar to FIG. 4 but showing the rotating shutter of the switch in a different rotating position;
FIG. 7 is a horizontal sectional view of the selector switch of FIG. 4 taken substantially along line 7-7;
FIG. 8 is a plan view of a metal strip such as may be intermittently fed by the cutting or stamping press of FIG. 1 and which shows the marks applied to the strip for registering purposes;
FIG. 9 is a plan view similar to FIG. 8 wherein the registering marks are greater in width;
FIG. 10 is a view depicting the scanning of the strip with the instant of scanning being shown as occuring in the lead zone;
FIG. 11 is a view similar to FIG. 10 but wherein the instant of scanning occurs in the lag zone;
FIG. 12 includes several views which graphically illustrate the scanning of the strip to determine whether the mark is registering properly or whether the mark is being detected in either the lead or the lag zones; and
FIG. 13 is a diagrammatic view illustrating one complete revolution of the press operating shaft and which shows the angular period preferred for activating the present automatic registering apparatus.
FIG. 1 of the drawings shows in outline the head 10 of a cutting or stamping press having a main operating shaft 11 which is continuously driven by drive means, not shown, in a clockwise direction. The shaft 11 drives the upper and lower feed rolls l2 and 14 shown in FIG. 2 in an intermittent manner by means of rack and pinion mechanism or crank am and ratchet mechanism. The strip material passes between the feed rolls and thus the rolls feed the strip intermittently and in desired feed lengths. Rack and pinion mechanism for feeding strip material in an intermittent manner is shown in the Littell and Wiig US. Pat. No. 2,758,837 granted Aug. 14, 1956 and titled Hydraulically Powered Rack and Pinion Feeding Mechanism and also in the Budlong US. Pat. No. 2,856,793
granted Oct. 2 I 1958 and titled Adjustable Cranks.
Although the main operating shaft 11 drives the feed rolls 12 and 14 in an intermittent manner, the said shaft also drives the shutter of the selector switch, FIGS. 4 and 5, at a one to one ratio. For this purpose the shaft 11 as shown in FIG. 1 mounts a pulley or sprocket 15 which has operative connection with the endless belt or chain 16, and at its opposite end the same passes around the pulley or sprocket 17 fixed to the selector switch shaft 18. The endless connecting member 16 after passing around 17 is caused to pass over the idler pulley 20 and the entire mechanism is generally housed within the elongated cover 21. Thus the shutter of the selector switch is timed as regards its rotating action with the stamping or cutting operations of the press. Such co-action between the said parts is necessary since the selector switch determines the several instants in the continuous scanning of the strip when the electric motor is pulsed should a correction in the registration of the mark be necessary. In accordance with the invention the electric motor upon being pulsed will drive the brake mechanism and through the brake mechanism it drives the feed rolls to either advance or retard them and thus effect a correction in the registration. The brake structure as shown in FIGS. 2 and 3 will now be described.
The feed rolls 12 and 14 are joumaled for rotation by the shafts 22 and 24 respectively and each shaft has its left hand end reduced in diameter, the said ends entering the brake housing 25 for receiving gears which operatively connect the upper and lower feed rolls so that they rotate together for feeding the strip material. The shaft 22 is reduced at 26 for receiving the ball bearing assembly 27 and the pinion 28. The shaft 24 is also reduced in diameter at 30 and this end receives the ball bearing assembly 31 and the gear 32 which has meshing relation with the pinion 28. The brake housing 25 is suitably supported from the frame of the press by the supporting member 33. A ring plate 34 for enclosing the gear wheel 35 and the cover plate 36 substantially complete the housing of the brake device.
The gear wheel 35 is driven by the pulsed electric motor 37 in a manner to be presently described, but first it should be observed that gear wheel 35 is rotatably mounted on the hub 38 of gear 32 by the ball bearing assembly 40 so that all driving from the gear wheel to shaft 24 will take place through the friction brake discs of the brake device. The shaft end 30 beyond the gear wheel 35 is formed with a flange to which is secured the hub 38 by the machine screws 41. The said gear 35 is fixedly secured by the machine screws 42 to the collar 43 which is secured in turn to the brake mounting plate 44 by the bolts 45, the collar thus having surrounding relation with the flange.
The brake mounting plate carries two or more plate supporting bolts 46 which are fixedly secured in angular spaced relation adjacent the periphery of the mounting plate by the nuts 47. The bottom pressure plate 50 is suitably mounted on the bolts 46, the pressure plate having surrounding relation with the hub portion 51 and said plate having its friction surface 52 facing in a direction towards the left. The top and movable pressure plate 53 is similarly mounted on the bolts 46 so as to surround the hub portion 51 and this top plate has its friction surface 52 facing towards the right. The reduced portion 30 is further reduced at its terminal end for receiving the hub portion 51 which has the brake discs 54 and 55 integral therewith. The brake discs are alternately spaced for cooling and each disc carries an insert 56 formed of brake lining. The lining of brake disc 54 is in contact with the friction surface 52 of the pressure plate 50 whereas the lining of the disc 55 is in contact with the friction surface 52 of pressure plate 53. Spring pressure is applied to the pressure plate 53 by the cross bar member 57 which is mounted on the bolts 46 in much the same manner as the pressure plates and which has pivotal contact at points 58 with the pressure plate 53. The coil springs 60, carried by the bolts 46 and confined between the cross bar member 57 and the end nuts 61, apply the required resilient pressure to produce the desired braking action by reason of the brake disc'54 and 55 having frictional contact with the pressure plates 50 and 53. From the foregoing it will be understood that the rotating action of the feed rolls 12 and 14 is resiliently braked at all times since the hub portion 51 is keyed to the terminal end of the shaft 24 and said shaft is geared to shaft 22. The compression forces on the brake discs is adjustable in that the nuts 61 can be tightened down on the coil springs 60 or released as desired.
As best shown in FIG. 3 the gear wheel 35 has meshing relation with the worm gear 62 on the shaft 63 which is suitably journaled for rotation in the elongated sleeve 64 carried by the supporting member 33. The left hand end of the shaft 63 has the sprocket 68 secured thereto and the endless chain 66 passes around the sprocket 65 at one end and around the sprocket 67 at its opposite end. The sprocket 67 has a geared connection with the motor 37 which is suitably supported from the supporting member 33. When the motor is pulsed the drive from the motor is transmitted through the sprockets and chain to the worm gear 62 to cause micro-movements of the gear wheel 35. These micro-movements of the gear wheel are transmitted through the brake device to the feed rolls 12 and 14.
Referring again to FIG. 3, this Figure shows the strip material 70 as passing under the scanner 71 and as then passing between the feed rolls 12 and 14. The scanner is shown in the diagrammatic views FIGS. and 11 as consisting of a light source 72 which is directed onto the surface of the strip and a receiver 73 in the form of a photoelectric cell which receives the light reflected from the strip material. The scanning of the strip is continuous and as shown in FIG. 10 the scanning is taking place in the lead zone immediately in advance of the register mark 74 whereasin FIG. 11 the instant of scanning is taking place in the lag zone. These scanning moments in the continuous scanning of the strip are controlled by the selector switch 17 FIG. 1, and which is shown in detail in FIGS. 4 to 7 inclusive.
The selector switch 17 employs a pair of light sources and respective photoelectric cells which are rendered active at predetermined instants with respect to the moving strip material. Stated more specifically the rotating shutter of the selector switch renders the switch responsive to scanner signals only in the leading and lagging zones. The housing 75 of the selector switch is suitably supported from the frame of the press and the shaft 18, which rotates synchronously with the main operating shaft 11 of the press, enters the housing through the hub portion 76. The end of shaft 18 within the housing projecting beyond the portion 76 has the supporting ring 77 fixedly secured thereto. The shutter consists of two overlapping and adjustable plates 78 and 80, the plate 78 being fixed to the ring 77 so as to rotate with shaft 18 and the overlapping plate 80 being adjustable since it is fixed to plate 78 by the screws 81. The outline of the plates is such as to provide a pair of shoulders on each plate and which are diametrically aligned. Thus for plate 78 the shoulders 82 are in diametrical alignment and the same can be said for the shoulders 84 of plate 80. The shoulders 82 are respectively disposed in adjacent opposed relation to shoulders 84 and by adjustment the gaps formed by the spaced shoulders can be varied in width.
As seen from FIG. 6, the gap formed by shoulders 84 and 82 is diametrically opposite the gap formed by shoulders 82 and 84 FIG. 4. The gaps provide the openings in the shutter that rotates with respect to a pair of spaced light sources and receivers which however are not diametrically aligned. The brackets 85 and 86 are integrally joined by the flat connecting member 87 and bracket 85 has a light source 88 and a photoelectric cell receiver 90 associated therewith. In a similar manner bracket 86 has the light source 91 and receiver 92 associated therewith. The light sources are located above the rotating shutter formed by the joined plates 78 and 80 and the receivers are located below the shutter. The brackets and connecting member as a unit is resiliently urged in an up direction, FIGS. 4 and 6, by the coil spring 93 which is fixed to the stud 94 projecting inwardly from the cover 95 at its top end and said spring at its bottom end connects with the part 96 projecting from the connecting member 87. For adjusting and controlling the position of the unitary bracket structure and thus the spaced light sources and receivers, the cam is provided and which is rotatable with respect to the member 87 having contact with a projection 98 on the member. The cam 97 can be rotated by the operator by rotating the knob 100. When the unitary bracket has been positioned as desired, the structure is secured in place to the cover 95 by tightening the thumb screws 101.
In FIGS. 4 and 6 the bracket structure has been positioned below the horizontal diameter passing through the shaft 18, and this locates the light sources 88 and 91 in position for receiving scanning signals for detecting the register mark in the lead and lag zones. The scanning of the strip by the scanner 71 is continuous and as the reflected light from the strip may vary so the electric signals generated by the receiver 73 will also vary, FIGS. 10 and 11. The light beams reflected onto the receiver 73 will be relatively strong and bright when the strip material is being scanned but when the dark register mark 74 is detected the brightness of the reflected light beams decreases considerably. This variation in the reflected light delivered to the receiver 73 will vary the electric energy delivered to the light sources 88 and 91 and thus the light projected by these sources will vary in the same manner.
The rotating shutter formed by the connecting plates 78 and 80 has rotation in timed relation to the operations of the press.
Also the gaps in the said shutter with respect to the adjusted light sources 88 and 91 are such as to permit the scanning signals from the lights 88 and 91 to be received by the photoelectric cells and 92 only in the lead and lag zones with respect to the register mark 74. It will be observed from FIG. 4 that the left hand gap is aligned with the light source 88 and the beam from that source will thus be directed onto the receiver 90. The shutter rotates clockwise and so immediately thereafter the right hand gap is aligned with the light source 91 and the beam from that source is directed onto the receiver 92.
When the mark is registering properly, both lead and lag zones are clear and the receivers 90 and 92 will not transmit any electric pulses to the motor 37. However should the mark be detected in the lag zone as shown graphically in FIG. 12, the motor will be pulsed in a direction to advance the strip material by advancing the feed rolls 12 and 14. The drive by the motor 37 is to the gear wheel 35 and then through the brake device to the feed rolls, and thus a correction is effected. In a similar manner when the mark is detected in the lead zone, then the motor 37 will be pulsed to retard or retract the strip material by causing the feed rolls to reverse thereby moving the register mark back. The brake structure cannot drive the feed rolls backwards during the feed cycle. However at the end of the feeding period, the drive housing is rotating in a reverse direction so that the brake structure can cause the feed rolls to reverse thereby causing the register mark to be moved back.
This feature of the invention is best illustrated in FIG. 13 which depicts one revolution of the press operating shaft and shows the period during which scanning preferably takes place and the period following the feeding cycle for activating the registering mechanism and effecting the micro-movements of the feed rolls to effect a correction when necessary.
FIGS. 8 and 9 show the strip material 70 as having registering marks of different widths. However even though the marks may vary in width the scanning can be adjusted and coordinated so that the strip is scanned only in the lead and lag zones as regards the mark. This is due to the fact that the gaps in the shutter are adjustable as to width since the plate 80 can be adjusted in position with respect to plate 78. Also the bracket structure is adjustable so that the location of the light source and receiver units namely 88 and 90 and also 91 and 92 can be varied as regards the shutter gaps. When the bracket structure has been positioned as desired it is held to the cover by tightening the thumb screws 10].
What is claimed is:
1. ln mechanism for detecting and maintaining accurate register of strip material having a registering mark thereon with lead and lag zones on respective sides of the mark and wherein said strip is fed intermittently in predetermined feed lengths, in combination, a pair of intermittently rotating feed rolls, brake mechanism in operative association with said feed rolls for frictionally braking the rolls during their rotation and for frictionally holding the rolls stationary between feeding cycles, electronic means for continuously scanning the strip material whereby said means produces electric signals as the surface of the strip and the register mark are alternately scanned, additional electric means for receiving said electric signals, shutter means in associated relation with said additional electric means and having rotation in synchronism with the feeding operations, whereby electric pulses are produced in the event the mark is detected in either the lag or the lead zones on respective sides of the mark, an electric motor in operative drive relation with the brake mechanism, and means delivering said electric pulses to the motor to activate the same for effecting a correction by efi'ecting a micro-movement of the feed rolls through the brake mechanism.
2. In mechanism for detecting and maintaining accurate register of strip material as defined by claim 1, wherein electronic means and the additional electric means each include a source of light and a receiver comprising a photoelectric cell for receiving reflected light from said source.
3. In mechanism for detecting and maintaining accurate register of strip material as defined by claim 1, wherein the electronic means includes a source of light and a receiver in the form of a photoelectric cell, wherein the electric means includes a pair of light sources and a photoelectric cell receiver for each, and the receiver of said electronic means being electrically connected to the light sources of said additional electric means.
4. In mechanism for detecting and maintaining accurate register of strip material as defined by claim 3, wherein the shutter means is located between the light sources of the said additional electric means and the receiver for said sources respectively.
5. In mechanism for detecting and maintaining accurate register of strip material having a registering mark thereon with lead and lag zones on respective sides of the mark and wherein said strip is fed intermittently in predetermined feed lengths,
in combination, a pair of intermittently rotating feed rolls, brake mechanism having friction discs in operative association with said feed rolls for frictionally braking the rolls during their rotation and for frictionally holding the rolls stationary between feeding cycles, electronic means for continuously scanning the strip material whereby said means produces electric signals as the surface of the strip and the register mark are alternately scanned, additional electric means for receiving said electric signals, shutter means in associated relation with said additional electric means and having rotation in synchronism with the feeding operations, whereby electric pulses are produced in the event the mark is detected in either the lag or the lead zones on respective sides of the mark, an electric motor in operative drive relation with the friction discs of the brake mechanism, and means delivering said electric pulses to the motor to activate the same immediately following a feeding operation for effecting a correction by effecting a micro-movement of the friction discs and thus a similar micro-movement of the feed rolls.
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