US2090858A - Paper web tensioning mechanism for printing presses - Google Patents

Description

1937- e. v. ANDERSON ET AL PAPER WEB TENSIONING MECHANISM FOR PRINTING PRESSES Filed Jan. 15, 1956 2 Sheets-Sheet l INVENTORSI M5555; Z. Conkhn,

WITNESSES:

g- 1937- G. v. ANDERSON ET AL 2,090,858 PAPER WEB TENSIONING MECHANISM FOR PRINTING PRESSES Filed Jan. 15, 1936 2 Sheets-Sheet 2 INVENTORS: Vflmderso n& y E. L'onkhn 7/ ORNEYS.

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Patented Aug. 24, 1937 PAPER- WEB TEN SIONING MECHANISM FOR PRINTING PRESSES i Gilbert V. Anderson, Philadelphia, and Wesley E. Conklin, 'Wyncote, Pa., ass'ignors to William F. Fischer, Philadelphia, Pa.

a restraining leverage member which is compreroll as'the supply on the latter dwinclles, as well Application January 15, 1936,' Serial No. 59,164

I 3 Claims. (01. 242-75) This invention relates to mechanism useful in hensively designated by the numeral 1, and connection with printing presses and the like to whichimposes a braking force upon said roll. In maintain paper webs under tension incident to they present instance, this restraining member being withdrawn from supply rolls; and it has constitutes a part of a means associated with the 8 reference more particularly to tensioning mechpress for bringing fresh paper supply rolls up to 5 anism of the type wherein the drag on the web speed in readiness to be substituted for exhaustis obtained as 'a consequence of the imposition ing rolls in a manner well known in'the art and of restraint upon the supply roll by a member which need not therefore be dwelt upon here. in pressure contact with the roll periphery; As shown, the restraining member 1 comprises With iiensinning mechanism 1' e yp SPe-- a frame consisting of a plurality of spaced arms cifically referred to, as heretofore constructed, 8, which, at their upper ends, are secured to a me yhas been p e ed in a ntaini transverse shaft 9- having .journal siipport in the tension-on the paper web constant due to the hearings in on the side frames 6 ofthe-press: disturbing influen e. pon the r r n n n m-v and a connecting cross bar ll joining said arms h r. of he rad ally decreasing diameter of the at their lower ends. Free on the shaft '9 are 15 paper roll as the supply thereon dwlndles in satpulleys i2 which are respectively coordinated, s y t e demands of the pressthrough a corresponding number of normally Our invention is directed toward ver m n idle endless flexible belts is of leather or the like, the above mentioned drawback; that is to say, 'with pulleys i5 carried by bearing yokes ii We aim to make possible themaintenance of a whereof the shanks II are slidiiigly engaged in m constant tension on the web throughout the unapertures 1 t cross b ll, Compression '20 Win i period of the supply roll. This desidersprings l8 interposed between heads I 9 at the atum we realize in practice, as hereinafter more lower ends of t yoke shanks n and t b fu y d l through provision of automatic tom surface of the cross bar Ii, serve to keep means whereby t e pressure on the restraining, the belts l3 taut. Respectively associated with member is varied comp ns v With the the free pulleys l2 on the shaft 8 are gear wheels 25 crease in. the diameter of the supply roll as the go which are pt tube motivated t the W is drawn therefrom proper time by means not illustrated to drive A further aim of our invention i Provide, i the belts l3, and thereby eflect rotation of the so web tensioning mechanism having the foregoing 1 by t m; t t bring t, up to attributes, manually adjustable control means speed as above explained, where y ny i degree of tension be The web tensioning mechanism '01 our inven- P ede m ed in the traveling P p tion further; includes an electric device in the Other objects and attendant advantages will form of a t ith an incdrporated app a f the detailed description which speed reducing unit, conventionally represented lows of the attached drawin s, wh I is at 2|, said motor being secured, at a suitable 4 a fra m tary and m or s di a t location, to one of the side frames ,6 of theprintview, in ngitudinal section, of a pr nt press ing press as shown in Fig. 11. 'Afllxed to the embodyin 0111' imp ved W b tensioning means; shaft 22 of the motor 2i is a miter gear pinion m and 23 that meshes with a companion miter gear 4 Fi II is View henrsa tl n' 85 it D- pinion 24 at one end of a short countershaft 25 pears when observed from the right of Fig. I. V journaled in a fixed bearing 26 adjacent .said

With m re detai d fer n to th illusmotor. A sprocket wheel 21 at the opposite end trations, i indi s t e upp y T011 from Which of the countershaft 25 is connected, by means of 5 the paper We 2 is co in ously d awn n the a chain 28, with a larger sprocket wheel 2. at

direction ind d y the rnw in Fi I ineione end of the transverse shaft 8 from which the dent to printing, the ends of the shaft 3 of said belt carrying frame is suspended. By action of roll being journaled for free rotation in open the-motor 2|, torqueis induced in the shaft 9 in bearings 4 on brackets 5 extending rearwardly the direction indicated by the arrow in Fig. I so I) from the side frames 6 of the printing press. that the belts i3 are caused to continuously bear The mechanism .which we have devised for against the outer surface of the roll i. maintaining a predeterminable uniform tension In order to vary th pressure of the belts l3 on the paper web 2 as it is being delivered to the on the roll I gradually, .i. e. to increase it comprinting instrumentalities of the press, includes nensatively' with decrease in the diameter of said 2 i f a,o90,ess

'10 the torque shaft I at the end opposite to that occupied by the sprocket wheel 2|, see 1"ig. II.-

There is also provided a manually adjustable rheostat 34 which is in series with the automa'tically actuated rheost'at II, and which serves as a master control whereby the mechanism can be set to maintain any desired degree of drag or tension on the paperweb I. The wiring connec- 4 tions between the motor II, the rheostats IO, 34

and the power line I! may otherwise be as showninr1g.1; r

The operation of the mechanism is as follows:

' Let it be assumed that'the printing press is in operation, and that the paper web 2 is being continuously drawn from the supply roll i in the direction indicated. By the clockwise torque induced in the shaft 0, thebelts it are maintained in idling pressure contact with the periphery of a the roll I, and at the same time caused to follow up on the latter as it decreases in diameter, with a attendant turning of said shaft. Through the sprocket chain connection 33, the contact arm II of the rheostat ill is concurrently shifted clockwise in Fig. I to gradually decrease the resistance in the circuit to the motor I i with the result that the torque induced in the shaft I is increased and this in turn followed by a corresponding increase in the pressure of the-belts it upon the roll I. It will thus be seen that, in this way. the restraint upon the supply roll I is varied. compensatively with decrease in the diameter of the latter and with the change-in the eifective leverage length of the member I. to the advantage that the web 1 is maintained under substantially constant tension (determined by setting of the manually adjustable rheostat N) throughout the entire period of unwinding of said roll, 7

By reversing the motor 2i upon near exhaustion of theroll l,'the belt carryingframe I can be retracted in preparation for the substitution of a fresh supply roll, The motor Il may moreover beutilisedtomaintainthebelts llincontact withthefreshmpplyrollasthelatterisbrought up to speed by driving of said belts through the ,gears 20 incident to the-substituting cycle of the change mechanism in a known manner.

The web tensioning mechanism herein specifically shown and described is of course to be con- 6 sidered as typical of other forms in which our-invention may be embodied within the scope of the appended claims.

Having thus described our invention, we claim:

1. Paper tensioning mechanism for printing l0 presses and the like including a shaft; an arm secured to the shaft; a restraining member carried by the arm and adapted to bear upon the peripheral surface of the supply roll from which the web is continuously drawn in satisfying the 15 demands of the press; an electric torque motor coordinated with the shaft and effective to keep' the restraining member in pressure contact with the roll;, and a rheostat automatically actuated from said shaft to vary the flow of electric current to the motor as-the diameter of the roll decreases and thereby maintain uniform tension on the web throughout the unwinding period of said roll.

2. Paper tensioning mechanism for printing presses and the like according to claim 1, including an auxiliary manually-operable rheostat in series with the first-mentioned rheostat whereby the electric current flow can be regulated to predetermine the degree of tension which.is to be maintained on the web.

3. Paper tensioningmechanism for printing 'resses and the like including a shaft; an arm secured to the shaft; a restraining member car- 31 ried by the arm and adapted to bear upon the peripheral surface of the supply roll from which the web is continuously drawn in satisfying the V demands of the press: electric means for inducing torque in the shaft to keep the restraining member in pressure contact with the roll; eiec- 'tric means actuated from the shaft for automatimeans.

GILBERT V. ANDERSON. 50 W E.

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