US2291627A

US2291627A - Web propelling roller drive

Info

Publication number: US2291627A
Application number: US361312A
Authority: US
Inventors: William F Huck
Original assignee: R Hoe and Co Inc
Current assignee: R Hoe and Co Inc
Priority date: 1940-10-15
Filing date: 1940-10-15
Publication date: 1942-08-04
Anticipated expiration: 1959-08-04

Description

Aug. 4, v1942. w, F, HUCK 2,291,627

' WEB PROPELLING RLLER DRIVE Filed Oct. l5, 1940 2 Sheets-Sheet l R2 lrbc. 7 2l 3425 2 R 2 R1 66 e2 3mm/'M l W/llam ff? Haack,

Aug. 4, 1942. w, F, HUCK f 2,291,627

wma PROPELLING ROLLER DRIvE Filed oct. 15. 1940 2 sheets-sneek 2 Patened Aug. 4, 1942 WEB PROPELLING ROLLER DRIVE William F. Huck, Richmond Hill, N. Y., assgnor to R. Hoe & Co., Inc., New York, N. Y., a. corporation of New York Application Octobcr 15, 1940, Serial No. 361,312 (ci. 27o- 5) 10 Claims.

This invention relates to printing machines, and more particularly to improvements in method and means for propelling webs through the conventional web paths in modern iotary printing lmachines.

' It has been the practice heretofore to drive the printing cylinders of the printing units at a `given peripheral speed, and to progressively in- '.,crease the peripheral speed of each .drag or propelling roller as such roller is-positioned'beyond the rst printing unit in the web path and towards the delivery portion of the machine. More specically, each web is led from the usual web supply roll under the requisite tension and then through the printing unit or units. The printing cylinders of each printing unit are driven at a given peripheral speed landthe web is guided in its path away from the unit, and travels at a linear speed substantially equal to the peripheral speed of the printing cylinders. One or more drag rollers may be positioned in the web path between a printing unit and the folder of the machine, and if more than one drag roller is employed, the rst is driven at a peripheral speed slightly greater thanthe peripheral speed of the printing cylinders, and the next is driven at a still greater peripheral speed. The web is then led over a propelling roller, usually positioned above the folder former, and this roller is driven at a peripheral speed slightly greater than the greatest speed of the drag rollers. The web is then led over the folder former or formers and between one or more pairs of nipping rollers which are driven at a peripheral speed slightly greater than the propelling roller. then cut and folded or otherwise discharged.

By progressively increasing the peripheral speed of the drag or propelling rollers, in the order in which such rollers are positioned in the web path beyond the printing unit or units, a taut web is insured, but. it is manifest that some slippage must occur between the peripheral surfaces of the propelling or drag rollers and the running web. This slippage is 'somewhat difficult to control properly, and it is otherwise objectionable inasmuch as it 'tends to smut or tear the freshly printed web, and furthermore the relative movement between the peripheral surface of the roller and the web tendsto reduce the fi ictional traction between the roller surface and the web, thus obviating the possibility ci obtaining the positive control that can be produced by driving 'the roller at web speed. If each propelling or drag roller, however, is positively driven at web speed, any slack that may be present initially or may occur The web is between the printing unit or units and the drag roller, or between the drag roller and subsequent propelling rollers could not be taken` up. Consequently, it is necessary in existent positive drives that the drag and propelling rollers be driven at progressively increased speeds as they are positioned towards the delivery portion of the machine. l.

The propelling roller and nipping rollers provided for the former are so located that they may be positively driven from the press drive, inasmuch as driving connections are available at this point. But even so, the positive driven rollers must be driven at peripheral speeds greater than web speed, in order to prevent slackness in the web, as hereinbefore pointed out.

It is, therefore, an object of this invention tov provide improved method and means for driving each drag roller, propelling roller or nippingr roller of a rotary printing machine through an independent drive instrumentality which causes the roller to conform to web speeds but to exert a constant torque pull on the web, which torque pull is so controlled as not to exceed the frictional resistence existent between the roller surface and the web, thus avoiding any slippage between the roller surface and the web.

Another object of this invention is to provide improved method and means for ydrivingveach drag roller, propelling roller or nipping roller in the web path of the printing machine through an independent drive which causes each roller to conform to web speed but to exert a constant torque pull on the web, this torque pull being controlled so that it does not exceed the fricwhich conforms to web speed, the roller maintaining a torque pull on the web which is substantially constant at starting and running speeds and throughout the range of accelerating speeds of the roller, the electric current for the motor being supplied through a motor generatorset and a press driven generator' electrically connected in suitable electric circuits.

It is also an object of this invention to provide improved web propelling means for printing machines, which include an independent electric Iperipheral speed conforms to the web speed but exerts a constant torque pull on the web, the torque of the roller being so controlled asnnot to exceed the frictional resistance existent between the roller surface and the web, thereby avoiding any slippage between the roller surface and the web.

With the foregoing and other objects in view,

which will appear as the description proceeds,

the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that various changes in form, proportion, and minor details of construction may be made within the scope of the claims without departing from the spirit or sacrificing any advantages of the invention.

For a complete description of the invention, a detailed description of the improved method and means for driving printing machine web propelling rollers will now be given in connection with the accompanying drawings forming a part of the vspecification wherein: Y

Figure 1 is a diagrammatic side view of a printing machine, showing a preferred form of the invention applied thereto:

Figure 2 is a diagrammatic plan view;

Figure 3 is a diagrammatic plan view of a printing machine showing a modified form of the invention applied thereto;

Figure 4 is a fragmental diagrammatic side view thereof;

Figure 5 is a longitudinal sectional view taken through a yieldable drive unit;

Figure 6 is an end view thereof;

Figure 7 is an electrical diagram of the cir'- cuits supplying current to the torque motors; and

Figure 8 is a plan view of one motor driving geared nipping rollers.

Referring to the drawings in which similar .reference characters designate corresponding parts, ln Figures 1 and 2, there is depicted, in diagrammatic form, a quadruple printing press which includes a base I0 that supports the usual frame components II for a folder F. 'I'he printing units, and the web guides, in conformity with the usual practice, have suitable frame members, not shown, which arev supported on the base. Rotatably supported at one terminal of the base I'II are a plurality of web supply rolls- I2, and the web W from the upper rolls I2 is led over and around guide rollers |3 to and through the first perfecting printing unit A. 'I'he printing unit A is of conventional construction and includes a plate or form cylinder I5 which cooperates with an impression cylinder I6 to print one side of the web, and a second plate or form cylinder` II which cooperates with a second impression cylinder I8 to perfect or print'the other side of the web. The perfected web is then led from the printing unit A over guide rollers 20 to a drag or web propelling roller 2|.

The web W may now be slit into separate ribbons R and RI, and the ribbon R is led over and around guide rollers 22 to a second drag roller or web propelling roller 23 located adjacent and above the former f of the conventional folder F. The ribbon RI may be diverted from its path of travel by passing it over and around turner bars 25, so that it isrpositioned immediately below the web R, and then it is led over and around guide rollers 26 to the drag or propelling roller 23.

The web W' from the lower web supply roll I2 is led over and around guide rollers 2l to and through the second perfecting printing unit B, which unit is of conventional construction and is similar to unit A. After passing through the unit B, the web W is led over and around guide roller 28 toa drag or web propelling roller 30. The web W' may now be slit into separate ribbons R2 andR3, andthe ribbon R2 is led over and aroundfguide rollers 3| to the drag or propelling roller 23. The ribbon R3 may b'e diverted from its path of travel by passing it over and around selected turner bars 25, so that it is positioned immediately below the web R, and then it is led over and around guide rollers 32 to the drag or propelling roller 23.

Pressure rollers 34 may be supported in running engagement with the webs, to Dress them lagainst the drag or propelling rollers 2|, 23 and 30 and insure that the web is properly driven. In accordance with well known practice, the supports for these rollers are provided with suitable adjusting mechanism not shown. whereby their pressure on the web may be varied as required.

The four ribbons are led down over the former J to produce lthe conventional longitudinal fold, and they are then engaged by opposed web propelling or nipping rollers 33, and then the ribbons are conveyed through the folding cylinders, not shown, to the usual delivery mechanism, and finally delivered as finished products.

In the described arrangement, it is assumed that four ribbons are passed dowfn over one former, but of course, this is merely one of the many possible arrangements, and, if preferred, the webs may be slit and then so conveyed that one, two or more ribbons pass downwardly over each former, but in either event, the webs are propelled by the drag rollers 2| and 30, and the ribbons are propelled by the drag or propelling roller 23 and the nipping or web propelling rollers 33.

In the arrangement shown in Figures 1 and 2, the printing units A and B are driven from the line shaft S by suitable conventional drive in'- strumentalities. Each printing unit is provided with a vertical drive shaft 35 which is driven from the line shaft S through meshing bevel gears 35 and 31. The vertical shaft 35 of each printing unit drives a bevel gear 38 which meshes with a similar gear 40, which rotates with a helical or straight spur gear 4|, and this gear 4| meshes with a similar gear 42 which rotates with the plate or form cylinder I'I. The gear 42 meshes with a similar gear 43 which rotates with the impression cylinder I8, thus driving the plate and impression cylinders -|`I and I8 in unison. The gear 4| also meshes with a gear 45 which rotates with the impression cylinder I8, and the gear 45, in turn, meshes with a similar gear 43 which rotates with the plate cylinder I5, thus causing the plate and impression cylinders I3 and IB to rotate in unison. While in the depicted arrangement, only two printing units are indicated, it is to be understood, 'of course, that any preferred number of such units may be provided, and each u nit is positively driven from the line shaft S through the instrumentalities herein disclosed.

It has beenthe practice heretofore to positively drive the web propelling rollers through suitable drive instrumentalities or connections the motors.

which are driven from the press drive shaft S, and these web propelling rollers are so driven that the speed of each roller, as it is positioned away from the printing unit and towards the delivery terminal of the press, is progressively in-v creased. Such arrangement insures the taking up of any slack that may occur in the web in threading the press, but it also necessitates some slippage between the roller surface and the web, under all running conditions, and the difference between the-speed of the roller and that `of the web tends to smut or tear the freshly printed web. Furthermore, the setting of thepressure rollers 34 requires delicate adjustment, and it is also troublesome.` f f:

'I'he drag or web propelling rollers'2l and 30 are so located that it is both expensive andinconvenient to positively drive them from `existent drive instrumentalites of the machine, because no suitable drive shafts are available at this location. In addition to the great expense entailed in positively driving these rollers, there still remains the objec'ions hereinbefore stated.

In order t0 avoid the objectionable phases incident to the provision of mechanical drives for web propelling rollers, this invention contemplates the provision of means for individually driving each web propelling roller by a separate yieldable drive instrumentality which permits 'the roller surface to: conform to web speed and constantly maintain uniform torque pull on the web. In the arrangement depicted in Figures 1 and 2, an electric torque motor 5D is directly connected through an interposed shaft 5i with each web propelling roller 2|, 23, 30 and 33. The motors 5D for the drag and

web propelling rollers

2l, 23 and 30 are located at one side of the machine. These motors may be suitably supported on any convenient component ofthe machine frame. Inasmuch as the nipping or web propelling rollers 33 are-arranged in Apairs yin which one roller is located immediately adjacent the other to engage thefolded web, their `motors are preferably positioned atopposed terminals of each pair of the cooperating rollers 33 in order to avoidcrowding or interference of that, if desired, each pair of nipping rollers 33 may be geared together by suitable intermeshing gears 33a and driven by a single motor, as diagrammatically indicated in Figure 8.

The requisite voltage'is applied to each-motor Yso that the desired torque will be `constantly maintained at starting and all running speeds, and also, throughout the accelerating range up to While a vseparate motor is shown p for each nippingl roller 33, it will be understood.

top speed. This is accomplished by instrumen- Vroller is restrained to the linear speed of the web by the frictional engagement between the roller p surface and the web, thus producing a constant torque pull on the web. This torque is seconinsuring that the roller surface 'and the web travel at the same speed, yalthough the roller is d constantly urged toward a higher speed by being driven at a .potential peripheral speedv greater than the linear speed of the web. By this arrangement, a more positive control is insured at each propelling point, and, furthermore, the web will not slip on the roller surface and smut or tear the freshly printed web. Inasmuch as the propelling roller surface and the'web travel at vthe same speed, there is no relative movement to break -the frictional resistance set up at this point, thus insuring the maximumv propelling action or` drag for each web propelling roller.

' In the form of the invention disclosed in Figures 3,4, 'and 6, the press units A land B are driven `from the line shaft S and the web propelling or drag rollers 2| and 3l are driven-by the torque motors 50, as hereinbefore disclosed in the description of the form of the invention shown in Figures 1 andil. If preferred, however, the rollers ZIand 30 may be driven from the line torque clutches to. vbe 1 hereinafter described.A The web'propelling roll-5 ers 23'and'33, are preferably driven by mechan shaft Vsl through slip or ically connecting them with the line shaft S through the-yieldable orsllpclutches, as hereim after disclosed.

Referring to Figuresv 3 v'and 4,*it will be observed that the press drive or line .shaft S, in addition to driving the printing units lLand B, through th instrumentalities hereinbefo're disclosed,` also carries' a bevel gear'55 whichl meshes with a slmilar gearv 56. The gear'56 isfcarried by a' vertical shaft 51 whichis rotatably supported'in convenf tional bearings, not shown, adjacent"l the folder F. 'I'he `shaft 51,"at a pointiintermediate its .terminals,carries Aa bevel gear 53L which meshes With a similar gear supported at one'terminal of a horizontal transversely-disposed shaft '61.

'The shaft 6I carriesfour bevel gears 62 whichV mesh with similar gears 63, and each gear 63 is carried at the outer terminal of a stub haft 66.

A'sjbest shownin yFigures 5 and 6, the inner terminal of each stubL shaft 6 5 is rotatably recei'ved within a bearing 6 6 Aformedin one terminal of a `clutch housing ,61 of a slipor torque clutch de' parted to the clutch face 12 of the flange 66. A .collar 13 is pinned or otherwise -secured to the shaft 65, and engages the outer termina-ll of the bearing 6 6 to thereby cooperate with the flange sleeve 10 jand thrust bearing 1I to hold the shaft 65- againstlongitudinal movement relative to the bearing l66 and housing 61. "A shaft 15is rotatably received in a bearing 16 formedat the opposed `terminal of the clutch housing 61, and this trolled that it does not exceed the frictional re-'j f sistance existent between the peripheral surface of each web propelling roller and the web,thus

shaft -15 is lheld against longitudinal movement relativeto the bearing 116 and housing 61 by spaced collars. 11 which are (pinned or otherwise secured to the shaft 15.- `I'he hub or sleeve por- -tion16 ofja clutch flange or head 80 is mounted on the shaft 15 for longitudinal movement yrelavtivethereto, but. it is held against rotary motion @relative to .the shaft 15 by a key or other secur-Y ing'- instrumentality 6|.. Clutch discs 82 are secured to theclutch faces ofthe clutch flanges 6l fand 8 0 and are held in yielding engagement with f v each other by a helical spring 83 which surrounds the sleeveor hub 18 of the clutchhead 80. One terminal of this spring engages the flange of the clutch head 80, and the opposed terminal engages an antifriction thrust bearing which is slidably mounted on the clutch sleeve '18.. A bifurcated arm v8 6 straddles the clutch sleeve 18, `and its bifurcated portion engages the outer face ofthe thrust bearing. 85. The arm 8B is .keyed o r otherwise rigidly secured to a shaft 81 which is rotatably received in bearingapertures 88 formed in `the clutch housing 61. The shaft 81 extends outwardly beyond the housing, and the sleeve or hub 90 of an actuating finger 9| is pinned orotherwise rigidly secured to the shaft 81. A lug or ear 92 extends outwardly from theclutch housing 61 and is provided With a threaded aperture which receives a threaded stem 93 carried by a hand or manipulating wheel 95, and the inner terminal of the threaded stem engagesthe outer face of the actuating finger 9|. Byfthis arrangement, the tension on the spring 83 may .be readily adjusted by rotating.` the manipulating wheel or handle 95 to thus predetermine the pressure with which the clutch discs 82 engage each other, u

-The clutch housing is preferably filled with oil,`grease or suitable lubricant, andthe hand wheel or handle 95 is Vmanipulated to produce the requisite frictional engagement between the clutch discs,82carried by the clutch flanges E8 and 80. l. By this arrangement, the rotating stub shaft 65 of each clutch device 64 imparts the requisite torque'to the shaft 15, for a purpose-t0 be vention, each nipping-,roller or web propelling roller 33 is securedto a shaft 'l5 so that the roller is driventhrough-the slipping clutch device. In Figure 3, a separate Aclutch device 64 is shown for each roller v33.but it will be understood that eachpair of rollers 33 may be geared together as hereinbefore stated, and that a single clutch devicemay be employed to drive both'as indi.

catedinFi811re8. 1

. `A'bevel gear |00, shown in Figures 3 and 4, is secured to the upper terminal of the shaft 51,

Aand this gear meshes' with a bevel pinion |0| carried? bya longitudinally extending horizontal shaft-|02 which carries a bevel gear |03. The

- page, but exert the requisite torque pull on the webs or ribbons. In this form of the invention, the slipping clutch devices 64 drive the

rollers

23 and 33 insteadof the torque motors, because, at this location, drive instrumentalities are available.

Inasmuch as mechanical driving connections are not available for the drag rollers 2| and 30 unless the necessaryl gears and shafting to con'- nect them with the shaft S are provided, in most printing machines these rollers are preferably driven by independent torque motors 50. It is obvious, however, that if driving connections on the machine are available, a slipping clutch device 64 may be employed to drive each of the drag rollers 2| and 30;

In arrangements' where the web propelling and i nipping

rollers

23 and 33 are positively driven from the press drive, in conformity with previous practice, these drives are effected through instrumentalities similar to those disclosed in Figure 3, except that the slipping clutches 64 are not employed, but, in such arrangements, it is necessary, as hereinbefore stated, to drive the

rollers

23 and 33 at speeds slightly in excess of web speed, and the speed of each roller is progressively increased as it is positioned towards the deliveryterminal of the machine.

W'here propelling rollers are driven by independent electric torque motors 50, the torque on each motor is automatically controlled so that it vhereinafter disclosed.'` In this form of the inbevel gear |03 meshes with a bevel pinion |05, A.

A may be'secured to the machine frame in any suitable orv preferred mannen'and inasmuch as such mountings are wellknown and understood bythose skilled in the art, they have, for the sake of simplicity, been 'omittedin the drawings.

11n ythis form ofthe inventiomthe printing units A' and B are driven from' the drive or line shaft S, and,fas` hereinb'efore pointed out, the peripheral speed of the cylinders of the printing units control the linear, speed of the webs and ribbons. Each drag roller' 2| and 30 is individually controlled by a torquemotor 50, as hereinbefore stated; and the dragV or web propelling roller 23,and. the'nipping or web' propelling rollers 33 are each controlled by a slipping clutch arrangement 64, and, inasmuch as `the torque imparted through each slipping-clutch can be adjustably controlled to the requisite degree, it is manifest that the

rollers

23 and 33 rotate with the web without slipwill impose the desired pull on the web. This is accomplished by providing the proper voltage to each torque motor so that the desired torque .will be substantially constant at starting and all rimning. speeds, that is, there must be adequate torque imposed on the motor before it starts to move, and also throughout its accelerating range up to top speed and during running speed. This is accomplished by the provision of a motor generator set and one or two press driven generators, as indicated in the diagrammatic Figure 7, and which will be more fully disclosed hereinafter. The press driven generator supplies the greater part of the electric power required to drive the torque motors 50 for the drag or web propelling rollers, and the voltage-of this generator, which is shunt wound, will vary substantially in proportion to press speed. The constant speed generator of the motor generator set will preferably generate about 10% of the voltage generated by the press driven generator when the press is running at full Speed. Thus it yis to be understood that 10% of the full voltage is imposed on the motor before the press starts and provides the requisite torque to insure proper web tension in starting. Thereafter the press driven generator voltage increases as the pressaccelerates, and the torque motor receives a corresponding increased voltage thereby increasingthe speed and torque proportionately. In the preferred arrangement, as herein disclosed, a second small generator is provided that is driven at constant speed, and the.

convenient circuit, and this motor drivesl generators H2 and H3 independently" of the printing machine drive The torque motors`50, as hereinbefore disclosed, are directly connected with the web propelling roller.

While the current supplied and generated may be commensurate with the load requirements, we may assume, for sake of illustration, that the'generator HIJ is of'one kilowattcapacity, 110 volts; generator H2 of 200 watts capacity, 15 volts; and generator H3 of 50 watts capacity, 10 volts. The Web propelling torque motors may be of one-fourth horse power capacity.

A direct current circuit is provided, which may V be of 110 volts potential, and the positive lead of the circuit is indicated at H5 and the negative lead at H6. The shunt field H1 of the machine driven generator Hl receives its energy from this circuit, and this field is connected .with the positive lead H of the circuit through lead H8. Generator H3 has its armature connected in series with the eld H1 of generator H0 through leads |20 and |2|, but it is connected in opposition to the line'voltage, as indicated, to buck its potential, in order to effect the desired automatic regulation of the voltage supplied to the armatures of the motors 50.

A The shunt fields of the motors 50 are energized from the 110 volt lines H5 and I I6 through leads |22 and |29. Generator H0, as stated, supplies most of the current for the armatures of the. torque motors 50, through leads |23 and I w25, but it is assisted by the generator H2, the armature and series fleld of which are in series with the armature of generator H0, as indicated, and impresses a potential of approxiin this circuit consequently determines the voltagev of generator H3.

As is usual in machines of this class, generator HU has a disproportionate change in voltage with small changes in speed in the higher speed range than it has in the lower speed range. In consequence, if the arrangement is suchthat it generates the proper voltage at low press speeds, it will generate excessive voltage at the higher press speeds. While this change,is not abrupt, and it is tapered over the range, it may be objectionable in some cases, and this objection may be overcome by the use of the generator H3, for it will be understood that the'field of generator H3 will receive more current at high press speeds and thus produce greater bucking effect, thereby reducing the eld current of generator H0 and accomplishing the desired regulation automatically.

A rheostat |21 is connected in parallel with the shunt field winding of motor H3 and provides means for regulating the Voltage generated by its armature, which as indicated above, reacts on the iield of generator HU. l

From the foregoing, it will be seen that the iields of motors 50 are connected acrcss aconstant voltage, while their armatures are connected -across a voltage that varies, depending upon the speed of the printing machine, but even when the machine is stopped, the. motors 50 are subjected to voltage `generated by the motor H2, and themotors 50 thereforevproduce a constant torque on the web propelling rollers to which they `are connected, at all press speeds. With the sevveral generators proportioned and arrange as diately above the other pair below each former.

It will, therefore, be understood that two pairs of rollers 33 through whichthe same web passes may be driven by either. the torquev motor arrangementi or the clutch devicesv 64, and, alternatively, the lower of the two pair of rollers may be driven by clutch devices 64, whi1e the upper rollers areprovided with torque motor drives. This'latter arrangement is particularly advantageous where it is desirable to simultaneously adjust the former and the nipping rollers adjacent same transversely with respect to the run of th web as is done in some cases. In such case, the clutch drive for the lower pair of rollers 33 is preferred because of their proximity to the folding cylinders.

While the drawings and the foregoing' description show the invention applied to a printing machine equipped with a folder, it will be evident to those versed in the art that the invention is equally applicable to machines in which products are delivered in sheet form and without being folded.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the pres*- ent embodiment be considered in all respects asv illustrative and not restrictive, and it will be further understood that each and every novel feature and combination present in or possessed by the mechanism herein disclosed forms a part of the 4invention included in this application.

Having thus described my invention, what 1 claim as new and useful is: y

1. The method of propelling a web'through a printing machine having a printing couple, a

lfolder having a former, a propelling roller located operably ahead of the former and nipping rollers located operably after the former, which consists in feeding the web through the printing couple and the folder at a linear speed which substantially equals the peripheral speed of the cylinders of the printing couple, `interposing a drag roller between the printing couple and the folder propelling roller, the drag roller, propelling roller and nipping rollers gripping the web to prevent slip to propel the web from the printing couple to and over the former, Yand yieldingly driving the drag roller, the folder propelling roller and nippingv rollers for a potential peripheral speed greater than the linear speed of the web to exert a torque pull on the web, controlling the torque pull of each roller so as not to exceed the gripl strain the peripheral speed of the roller to the linear speed of the web by the grip between the web and the roller.

2. The method of propelling a webthrough a printing machine having a printing couple and a former folder driven'by the machine drive, a propelling roller located operably ahead of the former of the folder, and nipping rollers located operably after the former, which consists in feeding the web through the printing couple and folder at a linear speed which substantially equals the peripheral speed of the cylinders of the printing couple, interposing a drag roller between the printing couple and the folder propelling roller, each roller gripping the web to prevent slip, driving each roller which is operably accessible to the machine drive4 through a slip clutch which is driven by the machine drive for a potential speed greater than the linear speed of the web to exert a torque pull on the web, and driving each roller which is inaccessible to the machine drive by an electric torque motor for a potential speed greater than the linear speed of the web to-exert a torque pull on the web, and controlling the torque pull of each roller so as not to exceeed the grip between the web and the roller to thereby restrain the peripheral speed of the roller to the linear speed of the web by the grip between the web and roller.

3. The method of propelling a web through a printing machine having a printing couple and a former folder driven by the machine drive; a propelling roller locatedoperably ahead of the former of the folder and nipping rollers located operably after the former, which consists in feeding the web through the printing couple and the folder at a linear speed which substantially equals the peripheral speed of the cylinders of the printing couple, interposing a drag roller between the printing couple and the folder propelling roller, each roller gripping the web to prevent slip, driving the drag roller by an electric torque motor, and driving the folder propelling roller and nipping rollers from the machine drive through slip clutches for a potential peripheral speed greater than the linear speed of the web to exert torque pull on the web, controlling the torque pull of each roller so as not to exceed the grip between the web and the roller to thereby restrain the peripheral speed of the roller to the linear sped of the web by the grip between the web and the roller.

4. The method of propelling a web through .a printing machine having a printing couple, a folder having a former, a propelling roller located operably ahead of the former and nipping rollers located operably after the former, which consists in feeding the web through `the printing couple and the folder at a linear speed which substantially equals the peripheral speed yof the cylinders of the printing couple, inter-posing a drag roller between the printing couple Vand the folder propelling roller, the drag roller, propelling roller and nipping rollers gripping the kweb to prevent slip to propel the web from the printing couple to and over the former, driving each roller by an electric torque motor for `a potential peripheral speed greater than the linear speed of the web to exert a torque pull on the web,controlling the torque pull of each roller so as not to exceed the frictional grip between the web and the roller to thereby restrain the peripheral speed of the roller to the linear speed of the web by the grip between the web and the roller.

5. The method of propelling a web through a printing machine'having a printing couple, a folder having a former, a propelling roller located operably ahead of the former and a pair of cooperating nipping rollers located operably after the former, which consists in feeding the web through the printing couple and the folder at a linear speed which -substantially equals the peripheral speed of the cylinders of the printing couple interposing a drag roller between the printing couple and the folder propelling roller, the drag roller, propelling roller and the nipping rollers gripping the web to prevent slip to propel the web. from the printing couple to and over the former, operably connecting the cooperating nipping rollers so that they rotate in unison, driving the drag roller, the propelling roller and the pair of cooperating nipping rollers by a separate electric torque motor for a potential peripheral speed greater than the linear speed of the web to exert a torque pull on the web, controlling the torque pull of the drag roller, the propelling roller and the cooperating pair of nipping rollers so as not to exceed the grip between the web and the rollers to thereby restrain the peripheral speed of the rollers to the linear speed of the web by the grip between the web and the rollers.

6. The method of propelling a web through a printing machine having a printing couple, a former folder driven by the machine drive, a propelling roller located operably ahead of the former of the folder and nipping rollers located operably after the former, which consists in feeding the web through the printing couple and the folder at a linear speed which substantially equals the peripheral speed of the cylinders of the printing couple, interposing a drag roller between the Aprinting couple and the folder propelling roller, each roller gripping the web to prevent slip to propel the web from the printing couple to and over the former, driving each roller from the machine drive through a friction slip clutch for a potential peripheral speed greater than the linear speed of the web to exert torque pull on the web, controlling the torque pull of each roller so as not to exceed the grip between the web and the roller to thereby restrain the peripheral nipping rollers located operably after the former,

which consists in feeding the web through the Lprinting couple and the folder at a linear speed which substantially equals the peripheral speed of the cylinders of the printing couple, interposing a drag roller between'the printing couple and the folder propelling roller, each roller gripping lthe web to prevent slip to vpropel the web from the yprinting couple .to .and over the former, operably connecting the cooperating nipping rollers `so that they rotate in unison, driving the drag roller, the propelling roller and the pair of co- -operating nipping rollers from the machine drive through a friction slip clutch for a potential pe- :ripheral speed greater than the linear speed of the `web to exert torque pull on the web, controlling the torque pull of the drag roller, the propelling roller and the pair 'of cooperating nipping `rollers so as not to exceed the frictional grip betweenthe web andthe vrollers to thereby restrain the peripheralspeed of each roller to the linear speed of the web by the grip between the web and the rollers.

8. In a rotary web printing machine having rotary printing cylinders, a delivery and a machine drive, a web forwarding roller between the printing cylinders and delivery and which grips the web, a frictionally driven slip clutch operably interposed between the machine drive and the web forwarding roller to drive said roller, the clutch including a closed housing, a drive member operably connecting with the machine drive and having a friction clutch face rotatable within the housing, a driven member operably connected with the web forwarding roller and having a friction clutch face rotatable within the housing and arranged for cooperable engagement with the driven friction clutch face, means for biasing the driven clutch face into frictional engagement with the drive clutchface, and means adjustable from a point outside of the housing to vary the degree of bias exerted by the driven clutch face against the drive clutch face.l

9. In a rotary web printing machine having printing cylinders and a delivery, a web forwarding roller between the printing cylinders and the delivery and against which the web is pressed, an

electric motor lto drive the roller, a first gengenerator, whereby the roller is `driven for a potential peripheral speed slightly higher than that of the printing cylinders andy maintains Aa substantially constant forward pull on the web.

l0. In a rotary web printing machine having printing cylinders and a folding mechanism with cooperating nipping rollers frictionally :gripping the web, an electric motor controlled by the speed of the machine and arranged to vdrive each nipping roller for a potential peripheral speed slightly higher than the speed of the printing cylinders by imparting torque to the roller of a value not to exceed the frictional grip between the web and the rollers to thereby restrain the peripheral speed of the rollers to the printing cylinder speed.

WILLIAM F. HUCK.