US1999164A - Registration compensating means - Google Patents

Description

xgm' 23, w35., T, M. AVERY 1,999,164

REGISTRATION oo MPENsATING MEANS I Fiied Aug. 25, 195o e sheets-sheet 1 Aprin v23, 1935; 1MM/Em y* 9 1,999,164

*l REGISTRATION COMPENSATING MEANS Filed Aug. 25, 1950 6 Sheets-Sheet 2 l l I I 1 1 Y .1

HHH IIIHHIM gva/vento@ dmq l pri 23, E935, T. M. AVERY REGISTRATION COMPENSATING MEANS www@ Filed Aug. 25', 1930 6 Sheets-Sheet 3 l S14/vento@ nnnnmmm lll/fillflfllsllglmlmm @19291995 1MM/Em 1,999,164

- REGISTRATION COMPENSATING MEANS I Filed Aug. 25, 1950 6 Sheets-Sheet 4 April 23, 19%., T. M. AVERY REGISTRATION COMPENSATING MEANS yFiled Aug. 25, 1950 6 Sheets-Sheet 5 Apml 23, 93. T. M. AVERY REGISTRATION COMPENSATING MEANS Filed Aug. 25. 1950 6 Sheets-Sheet 6 SW1/dolo 8 TT L1 Zi i) Patented Apro 23, 1935.

PATENT orriecls:

1,999,164 REGISTRATION. coMPENsATING -IvrEANs True M. Avery, Glens Falls, N. Y., assignor to Union Bag & Paper Corporation, Hudsonl Falls, N. Y., -a corporation of New Jersey Application August 25, 1930, Serial No. 477,679

ll Claim.

The present invention relates to improvements in registration compensating mechanism of the class used for maintaining correct registration between atravelling web and an element or elements of a machine through which the web passes and operate at intervals thereon, and it relates more particularly to means for maintaining correct registration between the travelling paper strip or web and the operative elements of a bag making machine through which the web passes and which act on the paper strip or web at intervals in its length to form bags' therefrom, mechanism of this class being shown and described in my prior Patent No. 1,517,099 granted Nov. 25, 1924 upon which is an improvement.

One of the primary bjects of the present invention is to provide a novel and improved detector for governing the operation of the registration compensating mecha 'smwhich embodies a photo-electric cell which responds to the movement of printed sections of the web past it and governs the operation of registration restoring means according to the relationship of such sections of the web with the operative element or elements of the machine actingr thereon.

Another object of the presentinvention isto provide means whereby the operation of registration restoring means may be governed by a detector which responds to the passage 'of the successive sections or bag lengths of the web without requiring the use of perforations in the web.

A further object of the invention is to provide a detector embodying a photo-electric cell which is adjustable to bring it into position torespond to the passage of any desired portions of the successive printed impressions or of special marks printed or otherwise applied to the web and thereby control the operation of the registration restoring means' according to the relationship ofi such printed impressions or marks with the operative element or elements of the machine acting thereon To these andxother ends, the invention consistsV v-in certain improvements and combinationsA and arrangements of parts all as will be hereinafter more fully described, the features of novelty b'eing pointed out particularly in the claim at the end cf the specification.

In the accompanying drawingst A.

1 is a side elevation of a paper bag making machine provided with web controlling means embodying the present invention;

Fig. 211s a vertical senction on an enlarged scale the present invention Fig. 4 is ahorizontal section taken on the line 5 Fig. 5 is a detail view intop plan and on an enlarged scale, of the timers of the detector mechanism;

Fig. 6 is a front elevation of the timers shown 10 in Fig. 5 y

Fig. 7 is a detail view in top plan of the detector which cooperates with the travelling web;

Fig. 8 is an elevation of the detector shown in Fis. '7; 15

Fig. 9 is a vertical section taken on the line 9--9 of Fig. 8;

Fig. 10 is a diagrammatic view showing the detector in cooperative relation with the travelling web, the timers connected to the detector, and the registration correcting means governed by the detector and timers, the parts being shown in the positions they occupy when the web is in correct registration with the operating element or elements of the machine; and

Fig. 11 is a view similar to Fig. 10 but showing the relationship between .the web and detector and the timers when the web is out of registration with the operative element or elements of the machine.

Similar parts are designated by the same reference characters in the several figures.

Registration compensating mechanism embodying the present invention is applicable generally to all uses where it is desirable or necessary to maintain correct registration between a travelling web of paper or other material and a device or mechanism which operates on or cooperates with the web at certain intervals in its length, whereby registration may be correctly 4o maintained between the travelling web and the device or mechanism which acts thereon. lThe invention is particularly useful in paper bag making machines for the purpose of maintaining correct registration between the continuously travelling web from which the bags are to be made, and which has been previously printed with advertising or other matter and the slitters, severing device or other parts of the machine which are intended to and should register very closely 5o with. the web in predetermined relationship with the printed impressions on the web, in order that the printed impressions will be at uniform height 'on all of the bags made on the machine.

The invention is shown in the present instance self-opening or automatic type, the machine beon the web at intervals in its length and in the tube passes,

ing similar to that shown and described in my prior patent hereinbefore referred to, it comprising a main frame I which supports the operating mechanism of the machine, a rack 2 which may be arranged at one end of the machine to support a roll of paper X in the form of a continuous strip which has been previously printed with advertisements or other imprints :r: `at intervals in its length, the strip of paper being fed pasta guide roller 3 into one end of the machine past a pair of guide rollers 4 and thence around a lguide roller 5 which is arranged opposite to 'a gum or adhesive applying roller. B which applies adhesive along an edge of the paper strip, the latter then passing beneath a former 1 which forms the paper strip into a tube in the manner usual in bag making machines of this class, the tube then passing between slitters 8 which operate dewith the imprints thereon to form tabs or flaps whichv serve to secure the bottoms of the completed bags. A pair of draw rolls 9 are provided beyond the slitters to cooperate with the bag tube and thereby draw the same through the machine, and a pair of pinch rollsh'Iil are provided beyond the draw rollsbetween which these pinch rolls acting on the paper tube to hold it while a breaker ilstrikes 'the paper tube about midway between the draw rolls 9 and the pinch rolls Ill and severs the tube into bag lengths, the lines of severance being in definite relation with the printed impressions nite relation on the tube. Folding and cooperative bag forming mechanism I2, the construction of which is well understood in the art is arranged beyond the pinch rolls I9 and cooperates with the severed bag sections to complete the formation of the bags. The pair of draw rolls 9 are mounted on shafts I3 and I4 respectively, these shafts being connected usually by gearing I5 to insure rotation of the two draw rolls at equal speed, the draw rolls gripping the paper tube between them and thus insuring advance of the web at a speed determined by the speed yof the draw rolls, and the draw rolls and also the slitters 8 and pinch rolls Ii) are driven from a main drive shaft iii through a gear I1 thereon which meshes with a gear I8, the latter being connected through the gears I9 to one of the slitter rolls 3, and the gear I8 meshing with a gear 20 which in turn meshes with a drive gear 2l for the draw rolls and also driving the pinch rolls I0 through suitable gearing as usual in bag making machines of this type. The breaker" II, which cooperates with the usual severing knife 22, is carried by a shaft 23 which is connected by gearing 24 to be driven from the shaft of one of the pinch rolls I0.

It will be understood that the slitters 3, pinch rolls I9 and breaker II are all driven from and at a definite speed in relation to that of the main drive shaft I6, but the draw rolls 9 which serve to advance the paper tube or web in relation to these elements of the machine are driven through a variable speed device soy that the paper tube or web may be driven at an increased or a diminished speed and thereby reestablish correct registrationv between it and the elements of the machine acting thereon whenever the paper tube or web is out of register with such elements of the machine. The variable speed device for driving the draw rolls ions 28 nasales shown in the present instance is like that shown and described in my prior patent hereinbefore referred to, its construction being briey as follows:

The driving gear for the draw rolls is fixed to a member 25 which is loosely mounted on the ,draw roll shaft I4 and is formed with an in ternal gear 26, and a spur gear 21'is keyed or otherwise fixed to the draw roll shaft I4, pinbeing interposed between the gear 21 andthe internal gear 26 and meshing therewith, these pinions being carried by a member 29 which is mounted loosely on the shaft I4 so that the axes of the pinions may be rotated about the center of the shaft I4 as an axis, in one direction or the other, thereby increasing orf-f`l` diminishing the ratio of speed transmission between the gear 2| and the draw rolls. The periphery of the pinion/carrying member 29 is formed with worm wheel teeth 30 with which a worm 3l meshes, this worm being fixed on a shaft 32 which latter is provided with a worm wheel 33 which is fixed thereto, and a worm 34 meshes with the worm wheel 33, the worm 34 being fixed on a shaft 35 which is coupled or otherwise connected to the shaft by a reversible electric motor 39. By this arrangement, when the electric motor 39 is energized to revolve in-one direction it will operate through the worm gearing described to rotate the pinion carrying member 29 "to carry the axes of the pinions 28 in one direction around the axis of the shaft I4 as a center to increase the ratio of speed transmission 'from the gear 2l to the shaft I4 relatively to the speed of operation of the slitters, pinch rolls and breaker and when the electric motor is energized to revolve it inthe ,opposite direction it will operate through the worm gearing described to rotate the pinion carrying member 29 in the opposite direction to carry the axes of the pinions 28 in the opposite direction about the axis of the shaft i4 as a center and thereby reduce or diminish the ratio of speed transmission from the gear 2| to the shaft I4 in relation to the speed at which the slitters, pinch rolls and breaker are driven, it being understood that/the speed of the draw rolls and hence of the paper tube or web acted on thereby will be thus increased or diminished while the slitters, pinch rolls and breaker continue to operate at a. constant or invariable speed and that while the electric motor is idle or stationary, the pinion carrying member 29 will be held from rotation and the ratio of speed transmission from the gear 2| through the pinions l28 roll shaft i4 will correspond with that of the drive for the slitters, pinch rolls and breaker, so that the draw rolls will then advance the paper tube or web at a speed corresponding with the speed of operation of these elements of the machine.

The present invention provides novel and irnproved means for detecting any variation that might exist between the 'printed impressions on the continuously travelling paper web and the slitters or breaker bar or other elementof the machine acting 'at intervals on the web and for automatically varying the relative speed of operation of the travelling web and such element or elements of the machine, as by governing the operation of the reversible electric motor 3E, as may be required, to restore correct registration between the web and said element or elements of the machine. Such means comprises timing and gear 21 to the draw means connected to be driven in synchronism with the slitters and breaker or other element of the machine which acts 'at definite intervals on the web and a cooperating device'which 'responds to the passage of each printed impression on the web or of each of a series of special marks or impressions printed or otherwise applied to the web in definite'relation with such printed impressions,l said device cooperating with the timing means to detect a. lack of registration between the printed impressions upon the web and the slitters, breaker or other element of the machine and to vary the relative speed of operation of the web and such element of the machine accordingly, as by governing the operation of the electric motor, to restore registration.

The timing means comprises preferably a pair of timing cams 3l and 38 xed'on shafts 39 and dll respectively, these shafts havinggears tl andr l2 of equal diameter` fixed thereon and said gears being connected by an intermediate gear t3 which causes the shafts 39 and it to revolve at equal speed. The cams 3l and 38 each have a high or raised portion 3l orl 38e extending around a part of its circumference, and the leadinglend 3W of the raised portion of the cam Sill and the rear or trailing end 38h of the raised Yportion of the cam 38 are located in approximately the same angular positions around the shafts and ill respectively. Contact arms ifi and are pivotally mounted at it and lll and cooperate with the respective cams, they being held in contact therewith by the springs lit and it respectively, and the Contact arms ld and d5 carry elec'- tricai contacts 5t and bt respectively which are arranged to engage relatively stationary. contacts if and 53 respectively when the contact arms rest on the relatively low parts of the respective cams as shown at the right hand side of Fig. 6 and to disengage from said stationary contacts when the contact arms engage the relatively raised or high portions of the cams, as shown at the left hand side of Fig. 6. The shafts 3% and (iii, connected by the gearing described, are'driven in enact synchronism with the slitters or breaker or other element of the machine which acts on the web at intervals in its length, these shafts being driven in the present instance by a gear 5ft which meshes with the gear d2 on one of the cam shafts, this gear `being fixed to a shaft 55 and the latter is connected by spiral or other gearing bt to a shaft tl, the latter shaft being driven in denite timed 'relation with one of the elements in the I machine, which acts on the web at intervals in its length, it being shown in the present instance yconnected by bevel gearing tt to the breaker shaft 23. The duration of the period during lwhich the contacts are closed depends upon the circumferential length of the raised portions of these cams. As shown the raised portion of ueach4 cam extends through approximately one-half its circumference so that the contacts controlled by each cam will be closed during approximately one-half a revolution of the cam, but by lengthening or shortening the circumferential length of the raised part of the cam, the period duringwhich the contacts are engaged will be reduced or increased relatively to the period of rotation of the cam. The relationship of the high and low portions of the` cams is such however that at the moment the slitters, breaker or other element of the `machine is ready to act on the 'paper tube or web, one contact arm is about to ride from the raised to the lowerportion of its cam while at the same time the other contact arm has just reached the raised or high part of its cam as shown diagrammatically in Fig.,10, and when the slitters, breaker .or other operative element of the machine is in advance or behind such a position, one of `the contact arms will rest on theraised part of its cam while the other Contact arm will rest on the lower part of its cam as is shown for example in Figure ll.

The device which responds to the passage of the printed impressions on the paper strip or web consists, according to the present invention, of ,a photo-electric cell or tube which may be of the type now in common use employing electrodes having a potential difference between them and Athe current flow through which is varied by variations in the amount of light to which the tube or cell is exposed. The photo-electric tube or cell, designated ilyaccording to the present invention, is so placed relatively to the travelling paper strip or web X that it will receive alternately varying amounts of light transmitted successivelylfrom the printed and intervening unprinted portions thereof, the printed portions of the web, especially when printed in dark or black ink, transmitting less light than the plain or unprinted portions thereof. In the preferred embodiment of the invention shown, the photoelectric cell or tube is so placed relatively to the travelling paper strip or web and a source of f light that it will successively receive light transmitted by reflection from the printed and intervening imprinted portions of the surface of 'the travelling paper strip or web, the light being reflected either from portions of the printed impressions :c on the web and the imprinted or plain intervening portions the web or from specially provided marks or spots :rf printed in dark or black ink or otherwise applied to the paper strip orweb in definite relationship with the printed impressions thereon and the clear portions of the paper strip or web intervening such marks or spots. Preferably, the photo-electric cell or tube is mounted in a light tight hood which serves to exclude stray light from extraneous sources, it having an aperture @i for admitting a beam of light thereto and to the photo-electric cell or tube therein from' the particular' part of the web used to control its operation, this aperture being located' at a suitable angle of reflection in rela,-

tion to the printed side of the paper strip or web Fiend a source of light preferably in the form of a lightprojector 62 is mounted also -at the printed side of .the paper strip or web X and is set at an angle corresponding to the angle of the aperture ofthe photo-electric tube so that the light projector will focus a highly condensed beam of light therefrom along the line a upon a given point in the plane of the printed face of the travelling paper strip or web, and the'light beam will be reflected from such point, by the surface of the travelling paperestrip or web, along the line b into the aperture, of the hood enclosing the photo-electric cell or tube. Any source of highly condensed and focussed light of suficient intensity may be used, the light projector 62 showncomprising a casing or lamp house Bt'to contain an electric light bulb 64 hav-f ing a reflector 64a beliindiit anda tube 65 through which light from fthe light bulb and reflector is t In some instances it may be desirable `to locate lends to the sides of the light projector and photo-electric cell or tube in such position in relation to the width of the travelling paper strip or web X as to cause transmission or reflection of light from thev printed of the paper strip or web, special marks or spots :c having less light transmitting or reecting properties may be printed in black or dark ink or otherwise applied alongside the row of printed impressions and at intervals in the length of the web in definite relationship with the printed impressions :z: thereon, photo-electric cell may be adjusted transversely of the web to cause them to cooperate with such specially provided marks or spots. For this purpose, the photo-electric cell or tube and light projector may be mounted on a slide 66, which is movable on a guide bar 61 which is fixed at its the machine and extends transversely thereof in a position opposite to the printed side of the travelling paper strip or web so that by adjusting the slide 66 along the guide bar, the light projector and the photo-electric cell or tube may be brought into cooperation with different portions of the paper strip or web in the direction of the Width thereof. The slide may be readily adjusted along the guide bar 61 by a screw 68 journalled in the front of the machine frame and cooperating with a nut 69 on the slide 63, this screw having a handle 10 arranged at the front of the machine for operation thereof. To facilitate focussing the beam of light a onto the desired area of the strip or web and insure reection thereof along the' line b into the aperture of the photo-electric cell housing, the light projector is pivotally mounted by a horizontal pivot 1I on the upper end of a vertical swivel pin 12 which is rotatable-about a vertical axis in a clamp 13 attached to the slide 66 the light projector being thus mounted for universal adjustment or adjustment angularly both longitudinally and transversely of the paper strip X and being held in adjusted position by tightening of the clamp 13,'and the hood 68 containing the photo-electric cell is preferably rotatable horizontally and adjustable vertically in a clamping band 1liu attached to the slide 66 so that the aperture 6l may be adjusted vertically and angularly in a direction transversely of the paper strip X to properly receive the' beam of light b reflected from the surface of the paper strip or web. By mounting both the light projector and the photoelectric cell on, the slide, they may be readily adjusted tov bring them into cooperation with any desired area in the vidth of the paper strip or web without disturbing the operative relationship between the light projec tor and the photo-electric cell. v

The photo-electric cell-59 is prbvided with a suitable amplifying relay 16 whereby the 'variations in the flow of the electric current through' the photo-electric cell produced by thepassage of the relatively dark printed impressions or the specially provided spots or marks and the inter.-v vening clear or unprinted areas of the .paper strip or web may be utilized to control the circuits of the reversible electric motor 36 to cause operation thereof in the proper direction to restore registration between the-travelling paper strip or web and the'elements in the machine act- -portions thereof while inand the light projector and Locales ing thereon when the web is out of' register therewith. The amplifying relay shown in the present instance is of a well known kind, it embodying a vacuum tube or thermionic device 15, a sensitive relay 16 and a contactor 11.

The photo-electric cell 59 has its anode a and cathode b connected by the wires c, d and e, f to the grid g and filament or cathode h of the vacuum tube or thermionic amplifying device 15, the latter being supplied with current for its operation by a transformer T, the primary terminals t and t of which are adapted to be connected to an ordinary alternating current lighting circuit, the transformer having a. secondary winding i connected by the conductors y' to the terminals of the filament or cathode h for heating itv and having a secondary winding k which is connected by the conductors l, m and m to the filament h and the anode or plate n of the amplifying tube 15 to provide a suitably energized anode circuit therefor, a portion of the Winding 1c being also connected in the circuit of the photoelectric cell to provide a potential difference between its electrodes. The transformer T also has a secondary winding o for supplying a biasing potential for the grid g of the amplifying tube 15, it being connected by theI conductors p, p' and q, q to the cathode h and the grid g respectively of the amplifying tube 15, a potentiometer P being bridged across the conductors p and q and having its movable resistance-varying element connected to the conductor q whereby the potential of the grid g may be varied yto adjust the sensitivity of the relay.

The sensitive relay 16 embodies an electromagnet r the winding of which is connected vin the output circuit of the amplifying tube 15 which includes the conductors Z, 'm and m', this relay comprising a pair of oppositely arranged contact members 1" andr2 which are connected to terminals 18 and 19 by the conductors r3 and r4 respectively, a switch tongue T5 being pivoted or otherwise movably mounted to engage one or the other of the contacts r and 1'2 under the control of an armature r6 which is actuated by the electro-magnet r, the switch 15 normally engaging the contact r2 but disengaging therefrom and engaging the contact r when the electro-magnet r is energized.

The primary winding t3 of the transformer is f conductors t4 and t5, the conductor t4 being connected to a terminal t6 of the contactar 11 and the conductor t5 being connected to the movable switch member ra of the sensitive relay 16. The contactor 11 comprises an electro-magnet u the, winding of which is connected to the terminal t8 and the terminal v of the contacter, the terminal v being connected by a flexible conductor v to'the terminal 19. The electro-magnet u of the contactoi' cooperates with a pivoted or movable armature w arranged'to cooperate with a pair of contacts 'y and z, the contacts y being connected by a conductor y to the-motor circuit terminal 89 and the contact z being connected by a conductor z' to the motor circuit terminal 88. With ,the conductor 1J' connected to the terminal 19 as fshown, the armature w of the electro-magnet u connected in the circuit of said winding will be engaged, the electro-magnet r of the sensitive relay being assumed to be deg-energized, but when the electro-magnet r is energized, the switch member T is disengaged from the contact member r2, the circuit of the electro-magnet u will be broken and the armature w will be retracted, thus breaking the circuit between the terminals y and e and thereby opening the motor circuit through the terminals 88 and 89.

The operation of the amplifying relay is briefly as followsz-An increase in the amount of light to which the electrodes of the light sensitive photo-electric cell 59 are subjected will cause an increase in current ow through the conductors c, d and e, f. Since the electrodes of the photoelectric cell are connected to the grid g and lavment h. of the amplifying tube l5 and assuming the biasing potential of the grid g to be suitably adjusted, such increased current now through the photo-electric cell will produce an increased flow of current of amplified strength through the amplifying'tube "l5, causing the electro-magnet r of the relay 'lli connected in the plate or output circuit of the tube 'i5 to be energized, thereby attracting the armature r6 and swinging the switch member T5 out of contact with the contact mern.

ber r2 and into contact with the contact member r', and when the exible conductor c is connected to the terminal 'iii as shown, the normally closed line circuit through the terminals yt and t and the electro-magnet u of the contactor il will be broken,thereby causing the armature w of the contacter to be retracted, thereby breaking the part ofthe motor circuit formed by the terminals y and z and tt and t@ and the connecting conductors y and 2'. When the amount of light to which the electrodes of the light sensitive photo-electric cell is suihciently reduced, the current flow in the circuit thereof connected to the amplifying tube 'i5 is reduced, thus reducing the current flow throughtthe amplifying tube, in

consequence or" which the electro-magnet r of the sensitivefrelay vllt is suiliciently cle-energized to allow the switch member T5 to move into engagement with the contact member r2, due to retraction of the armature rs, thereby closing the energizing circuit of `the electro-:magnet u of the' contactor il so that the electro-magnet u of the contacter will be energized by line current through conductor t4, terminals t6 and c of the electro-magnet, conductors 1J" and r4, contact member r2, switch member T5 and conductor t5, thereby causing the velectro-magnet u of the conductor to attract itsv armature w, causing it to bridge the contacts y and e and thereby close the motor circuit through the conductors y and a and across the terminals t8 and te.

While the amplifying relay as just described is arranged to open the lpart of the motor circuit between the terminals d8 and t@ when the photoelectric cell is exposed to an increase in light and to close the motor rcircuit when the amount of light reaching the photo-electric cell is sumciently reduced, the amplifying relay may be readily changed to operate in the reverse manner, that isiy to close the lelectric motor circuit when the `photo-electric cell is `exposed to an increased amount of light and to break the motor circuit when the amount of light reaching the photoelectric cell is suiciently reduced. This change requires merely the connecting 4of the conductor -fo'fto the terminallfl instead of to the terminal 19 as shown. 'When' thus changed, it' will be seen' that when .the electro-magnet r of the sensitive relay 'l5 is'energized by an increased current out- 5 put from the amplifying tube l5 resulting from an increased now/of current through the photovelectric cell due to the exposure thereof to an increased amount of light, the circuit of the electro-magnet u of the contactor, which will then be normally open between the contact member r and the switch member T5, will be closed by the swinging of the switch member 1'5 into engagement with the contact member r' by the attraction of vthe armature r6 of the sensitive relay, and the electro-magnet u of the contacter will then attract its armature w, closing the motor circuit through the conductors y and z and across the terminals y and e, and 88y and 89, and when the electro-magnet r is de-energized by a reduced current output from the amplifying tube l5 resulting froml a diminished or in-l terrupted now of current through the photoit disengaging from the contacts y and e and thus breaking the motor circuit between the terminals B8 and 89.

Using the amplifying relay as shown, the current ow through the photo-electric cell 59 will be reduced each time a printed area a: or one of the specially provided printed marks or spots is opposite to the aperture of the photo-electric cell, thereby causing closing of the part of the Circuit of thev electric motor 36 between the terminals B8 and 89, and an increased current flow through the photo-electric cell, which takes place when the intervening blank or unprinted areas of the surface of the web are opposite to the aperture of the photo-electric cell, will cause opening of this part of the circuit of the motor 36, the variation in the amount cf light reaching the photo-electric cell to cause its operation 'being produced by the difference in the lighttransmitting or reecting properties of the printed areas or marks or spots on the web and the intervening blank or unprinted portions of the web, the light-transmitting or reilecting power of the printed areas or marks or spots on the web,

especially when printed in black or dark ink, be-

ing much less than that of the blank or unprinted portions of the web. Y

The electric circuit connections between the various elements areas follows- 85 and B6 are conductors for supplying the operating current 'for the motor 36, these conductors being connectecl to any suitable source of current of proper voltage as forexarnple an electric generator tl.

, tact arms M and t5 respectively. The stationary .contacts 52 and 53 are connected by conductors 93 and 94 to theV remaining terminals of the reversible motor 36, it being understood that the motor is of the reversible typeand will revolve in one direction when energized by current sup- 70 plied by the conductor 85 and the conductor 93 and will .revolve inA the opposite or reverse di'- rection when energized by current supplied by the conductor 85 and the conductor 94.4 The operation of the registration compensatfil iii)

ing mechanism constructed as hereinbefore described is as follows:-

Assuming the invention is applied for example to a paper bag making machine and that the paper strip or web X from which the bags are to be made is printed with advertising matter or other printed impressions arranged successively in the direction of its length, either with or without the special marks or spots .'c', and that the paper strip or web is fed continuously through the machine by the draw rolls 9, and the photo-electric cell E@ and the cooperating light projector 62' are arranged to cooperate with the printed impressions on the web or with the specially provided marks or spots thereon, the running of the machine will cause the cams 3l? and 3d to operate in synchronism Vwith the sltters it, breaker i! and other elements of the machine which act at intervals on the paper strip or web, and as the raised part oi each cam reaches the respective contact arm, will he raised, disengaging the contact 50 or 5l thereon from the respective stationary contact 52 or 53, and when the low part of each ca m reaches the cooperating contact arm, the latter will be lowered thereby engaging the contact thereon with the respective stationary contact. The cams 3'! and 38 are so set relatively to the cut oir operation of the breaker on the web and the contacts 52 and 53 are so adjusted that while the printed bag sections of the travelling paper strip or web are in correct register with the slitters, breaker or other elements of the machine, the raised portion of one cam will have just raised one of the contact arms while the raised portion of the other cam will still hold the respective contact arm in raised position, at the moment one of the printed impressions :n on the paper strip X is opposite to the aperture 6| of the photo-electric cell,lassuming that the photoelectric cell 59 and the light projector 62 are adjusted to cooperate with the printed impressions .fr on the paper strip. Assuming the amplifying relay 'it to be connected so that the photo-electric cell will then close the circuit through the contacter terminals 38 and 89, the conductors 85 and Sii, Si and 92 will 'then be connected to the source of electric current supply for the motor 36 but the motor circuit will not be completed through either of the conductors elv and S2 since the contacts 5E! and 52 and 5i and iliwill be open as shown in Fig. l and hence the electric motor 3S will be idle or motionlessand the draw rolls 9 will operate todraw the paper strip or web through the machine without variation in their speed relatively to the slitters 3, breaker H or the other operative elements of the machine, the paper strip or web being then in proper register with the slitters, breaker and other element of the'machine so that these elements of the machine will operate on the paper strip or web in proper longitudinal relationship with the printed impressions thereon. While the paper strip or web is thus in proper registration with the operative elements of the machine acting upon it, the electric motor 3S and the variable speed driving.

means for the v.draw rolls will remain idle, the electric motor circuit being opened by both contact arms Mi and Reach time Aa printed impression :x: cornes opposite to the aperture of the photo-electric cell, However, should the paper strip lag or become advanced relatively to the slitters breaker or other operative elements ofthe machine so that these elements of the 'mathe latter chine would not operate on'the paper strip in proper longitudinal relationship with the printed impressions thereon, one or the other of the vcontact arms M and 45 will be in position to engage the electrical contacts controlled by it at the moment a printed impression on the paper strip is opposite to the aperture of the photo-electric cell and the resultant closing of the motor circuit through the contacter terminals 88 and 89 and the contacts engaged by the respective contact arm will cause operation of the motor 36 in a direction to increase or ,diminish the speed of operation of the draw rolls through the variable speed driving mechanism therefor, thereby restoring registration between the printed impressions on the travelling paper strip and the elements of the machine which operate thereon. For example, in Fig. 11, the paper strip or web X is shown in lagging relation to the cams 3l and the slitters, breaker and other elements of the machine which act on the paper strip, the contact arm i5 beingopposite to the low part of the cam 38 so that it is lowered and its contacts 5l and 53 are in engagement at the time a printed impression :n on the paper strip is opposite to the aperture of the photo-electric cell, and since the motor circuit through the contacter terminals B8 and 8d will be closed under these conditions, current will be supplied to the electric motor 36 through the conductors 85and 94 -to cause operation of the motor in a direction to lcause the variable speed driving mechanism for the draw rolls to operate the draw rolls at an increased speed relatively to the speed of operation of the slitters, breaker and other operative elements of the machine, and this operation will take place at each revolution of the cams 31 and 38 until the travelling paper strip has been brought into registration with the slitters, breaker and other elements ofthe machine as represented in Fig. 10, whereupon the motor 36 will become idle. If the paper strip or web becomes advanced or runs ahead of the slitters, breaker or other operative elements of the machine, the contact arm 44 instead of the contact arm 45 will be in its lowered position so that its contacts 58 and 52 will be closed at the moment a printed impression a: is opposite to the aperture of the photo-electriccell, and the electric motor 36 will then be caused to operate in the opposite direction through current supplied through the conductor 93 and the variable speed driving mechanism for the draw rolls will then operate in a direction to advance the paper strip or web at a reduced speed relatively to the speed of operation of the slitters, breaker orl other elements of the machine, and this operation will take place at each revolution of the cams until registration is restored between the printed impressions on the paper strip or web and the slitters, breaker or other elements of the ma. chine, whereupon the motor 36 will again become idle.

The operation may be the same when the row of marks or spots are printed or otherwise 3% which are synchronized with applied to the paper strip in definite relationf Y. ship with the' printed impressions thereon, these derstood that whilev the proper or ecientfunctioning. It will be unamplifying relay 14 may be adjusted so as to close the electric motor circuit across the terminals- 88 and 89 of the contactor ll when a printed impressions: or la mark or rspot a." on the paper strip is opposite to the photo-electric cell, the amplifying relay may be adjusted to close the motor circuit through the contactor terminals when a clear or unprinted area of thepaper strip or web is opposite to the photo-electric cell and thelatter`may be positioned accordingly to maintain registration between the paper strip and theslitters, breaker or other elements of the machine in' cooperation with the timing cams in the' manner hereinbefore described.

It will be understood that while .theregstration restoring operation is taking place involving either an increased or reduced speed of operation of the draw rolls, the motor 36 will operate to effect such result during each revolution of the'cams 31 and 38 and the motor will operate each time for the period of timey the contact arm 44 or 45, as the case may be, is in its lowered position as permittedi by its engagement with the low plortion of its respective can.; and by extending the-high or raised portions of the cams around their circumferences for a.greater or` less extent, the duration of the registration restoring operation of the motor 36 during each revolution of the cam may be reduced o'r in-l creased, if desired, since the lengthening or shortening of the raised portions of the cams at the ends thereof opposite the leading end 31.* of the cam 3l and the rear or trailing enlv38b of the cam 38 will, in effect, alter corresponding- 1y the lengths of the low portions of the cams.

While it yis generally preferable to employ the contactor of the amplifying relay and the cam controlled contact arms to directly control the operating circuit for the motor 36, as shown and described, obviously a relay like that shown for example in my prior patent hereinbefore re ferred to and governed by the contactor of the amplifying relay and ca -controlled contact lto -opening or automatic type, but it is obvious that .the invention is'also ymaking bags of the fiat, .square or satchel botapplicable to machines for tom and all other types. n

By employng a photo-electric cell to respond the passage of the printed impressions o r the marks or spots printed or otherwise applied to the paper strip or web in conjunction with the timing cams synchronized withthe slitters,

breaker or other elements of the machine which are intended to act on the paper lstrip in definite relationship with the printed impressions thereon, for detectng any lack of registration be- .tween the paper stripand such elements of' the machine and for controlling the operation of means for restoring such registration, proper registration may be` maintained between the paper strip and the machine`in a more and ecient manner than heretofore and it affords the further advantage that it renders'itprovide perforations in the paper unnecessary to strip as has been heretofore required.

I claim as my invention:-

simple In means for maintaining registration between f 'a travelling web having longitudinally` spaced areas of relatively different light reflecting powers on a surface thereof and an element of a the travelling web, a photo-electric cell and a light projector mounted opposite to said surface of the web in angular relation therewith to cause' la light beam to be projected onto said surface M. AVERY.

`machine actingv on said web, means for guiding

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