US2631790A - Web tensioning and driving mechanism - Google Patents

Description

March 17, 1953 G. H. WHELDON WEB TENSIONING AND DRIVING MECHANISM Filed Oct. 1, 1948 R. m m m 8 h GEORGE H- WHELDON BY ATTORNEYS Patented Mar. 17, 1953 WEB TENSIONING AND DRIVING MECHANISM George H. Wheldon, San Francisco, Calif. Application October 1, 1948, Serial No.- 52,377

6 Claims. 1

This invention relates to a web tensioning and driving mechanism. More particularly it relates to means for applying and maintaining proper tension to a Web of newsprint bein fed to a rotary press, and to stop the roll when the press motor is stoppedand to drive the roll at a proper speed at all times, and to mean for positively driving the roll at proper Speed.

In supplying a web to a rotary printing press. suchas a newspaperprintin' "press, a roll of newsprint is supported upon a reel. It.is a common practice to feed the Web from the re to the press by means of straps trained over rollers and driven at a speed which is governed by thev speed of the press, such as to unwind the roll at a proper speed and to maintain a proper 7 parted thereto. Also, the apparatus needed to adjust the straps is complicated and dim-cult to service. v

It is an object of the present invention to provide an improved means of driving and tensioning a roll of newsprint or the like for the purpose of feeding a web to a rotarypress.

It is a further object of the invention to provide driving and tensioning means for a roll of newsprint or the like, which means avoid the necessity of using straps. I

It is a still further object of the invention to provide an improved means of stopping the roll when the press motor is stopped. W Y

It is yet another object of the invention to provide a positive drive for a roll of newsprint or the like on a reel, which assures proper tension on the web. n

These and other ob ects of the invention will be apparent from the ensuing description and the appended claims.

One fornrwhich the invention may assume is exemplified in the following description and illustrated by way of example in the accompanying drawings, in which:

Fig. l is a fragmentary 'view in the device of the invention.

Fig. 2 is a transverse section taken along the line 2-2 of Fig. 1 and. showing also the electrical circuitforoperating the device, I 1

elevation I of Referring now to theidrawings, there is shown fragmentarily a reel I0 of known type including a :reel stand H having a shaft l2 journaled therein and extending between opposite posts of the'stand. The reel is of well known construction and isshown', *for example, in Wheldon 'et al, US. Patent No. 2,064,638, issued December 15, 1936, entitled We'b Tensioning Mechanism. Briefly, and as modified-for purposes of the present invention, the reel comprises threepairs of radial arms 13 and- I3a':'(of which only one-pair is shown), the arm" I'M-being fixed to the shaft 12 so as to rotate therewith'and the opposite arm i3 being rotatable on a sleeve M which in turn is rotatable on shaft I'Z'. Armsl3 and l3a are connected together'by' a bar I312 to cause "the armsto movefin unison; To the sleeve [4 are secured ears- 51 and 51a for a purpose explained hereinafter; v

A roll 'l5"-of newsprint wound upon a suitable core (not shown) is supported betweeneach pair of arms by means'of 'stubshafts E6 and spuds I1, the latter being'in'serted in the ends of the core. A's also described in'the above-mentioned patent, and as is well known in the art, the rolls mounted'u'pon such a reel are unwound one at a time, and as a'roll approaches exhaustion, a device known as a flying p-aster is employed to paste the'endof a-full roll to the web leavin the nearly exhausted roll,;after which the new roll is brought into operative position.

In accordance with the present invention, there is provided' 'at one end of each roll an hydraulic braking and tensioning mechanism generally'designated as'28 and, at the o posite end, a drive mechanism generally designated as 2|. These mechanisms are described in 'detail hereinafter. The hydraulic mechanism 28 is for the purpose of maintaining a proper, predetermined tension on the web, and to brake the roll' and bring it quickly to a stop in the eventthat the press motor is stopped. The drive 'm'echan'ism 2! is for the purpose of driving the 'roll at predetermined speedand to maintain 21a circuit for a liquid in the casing.

Disposed within the conduit 21 is a valve 28 supported upon-a pivotal shaft 29 which extends outwardly1ofithe'conduit. JSecured-to the 3 outer end of the shaft 29 is a lever at having a counterweight 3| secured thereto. The valve 28 is so disposed that fluid flowin through the circuit in the normal direction as indicated by the arrows, tends to open the valve whereas the counterweight tends to close the valve. A gauge Sin is also provided for measuring the hydraulic pressure in the conduit 21.

A solenoid 32 having leads 33 and 34 energized as and for a purpose described hereinafter, is also provided such solenoid having a plunger 35 secured to the lever 30 through the medium of a coil spring 36. Another solenoid 3211 having leads 3'! and 38, a plunger 35a and a coil spring 36a is also provided as and for a purpose described hereinafter and is similarly but oppositely connected to the lever 30 as illustrated.

It will be seen that, as the roll I4 is unwound, the shaft [6a, and with it the vanes 25, will rotate in a clockwise direction as viewed in Fig. 2, thus causing fluid to circulate through. the circuit as indicated by the arrows, and that the tendency of the fluid will be to open the valve :28 whereas the tendency of the counterweight 3| will be to close the same. By appropriate adjustment of the counterweight, it is apparent that any desired degree of resistance may be opposed to the flow of fluid and thus any desired de ree of brakin of the roll l4 and tensioning of the web may b applied.

Referring now to Fig. 2, a main press motor 40 is shown, such motor providing the power to drive the press at high speed. As is well known, and as described in Hentschell and Wheldon Patent No. l,929,114, issued October 3, 1933, entitled Automatic Break Web Switch and Cutter, the press drive mechanism may also include an auxiliary motor 40a to start the press and to operate the same at slow speed while the web is being threaded through the press, and a contact assembly switch (not shown) for stepping up the speed of the press motor and of the press. The system described in the above-mention-ed patent also includes means for automatically cutting the web when the press motor is stopped, such means being actuated by an E. M. F. generated by the press motor 40 when its main circuit has been broken. Details of this system will be found in the said patent and need not be repeated herein except for that portion of the press motor circuit illustrated in Fig. 2.

As there shown, the press motor 40 is provided with leads 4| and 42 which are energized by the main leads (not shown) of the press motor circuit, and it is also provided with a series field 43 and an armature 44. The motor is also provided with a field-45 which is constantly energized through leads 46 and 41.. The motor 40 is als prov d w th a shunt circ it including the above-mentioned leads 33 and 34 a d the so cnoid 32 connected in shunt with the armature and s ries field winding of the motor 40. This circuit is controlled by a switch 48 which isnormally closed but is kept open when the main ircuit of the motor is closed. This is accomplished by means of a solenoid 49 which is energized by the motor circuit through leads 50 and Solenoid 49 is of such capacity that it is operative when energized from main lines 4| and 4,2 to hold switch 48 in open position but is incapable of holding the switch in open position when supplied with the E. M. F. produced by the motor 40 after the main switch is open. As long as the main motor circuitis closed, theswitch 4!! is open, and, hence. the shunt circuit is broken 4 and the solenoid 32 is de-energized. When, how ever, the main motor circuit is broken, the switch 48, hence also the shunt circuit, is closed.

It is apparent that when, for any reason, the main press motor circuit is broken, the armature 44 will continue to rotate for a brief period owing to its momentum, and that because of the field 45, the motor 40 will generate an M. F. By reason of the closingv of switch. 48 and of the press motor shunt circuit, the solenoid 32 will be energized. Accordingly, the lever 30 will be pivoted and the valve 28 urged to closed position, thus providing an extra braking action on the roll IE to bring it quickly to a stop.

In summary, it will be seen that whenever the mainswitch is closed, solenoid 49, being energized by main line current, will hold switch 43 in open position so that solenoid 32 is dc-energized. However, when the main switch is open, solenoid 49 will be de-energized from main line current and therefore switch 48 will close.

The continued rotation of motor 40 will pro duce an E. M. F. sufiicient to energize and cause actuation of solenoid 32 to close valve 28. However, this E. M. F, produced by motor 40 is not sufficient to cause solenoid 49 to open switch is and therefore the switch remains closed until solenoid 49 is again supplied with main line current.

As stated, the auxiliary motor Add is employed to operate the press at slow speed, as when the web is being threaded through the press. During such an operation it is desirable to relieve tension upon the web, which can be accomplished manually by means of the lever .30 or by adjustmg the counter-Weight 3L. Preferably, however. automatic means of relieving such tension is provided.

Such automatic means is provided by the solenoid 32a, which is energized in the manner now to be described. The auxiliary motor 4% is energized through loads 52 and 53 and a series field 54. As shown, the solenoid 32a is in circuit with the auxiliary motor through the leads 31 and 38. When, therefore, the auxiliary motor 401; is energized, the solenoid 32a is also energized and its plunger acts on the lever 39 to open the valve 23, thus relieving tension on the web.

Referring again to Fig. 1, the driving mechanism 2| comprises a drive shaft 55 driven by h press motor and having a bevel pinion 55 secure thereto, a bevel gear 51 secured to the sleeve l4 and in mesh with the pinion 56. and a dou l bevel s ar 51a secured to the other end of the sl v H! as shown, A splined shaft 58 and a screw shaft 59 are also provided, being arranged in parallelism and journaled in bearing brackets supported by the arm I3 as illustrat d. Th shaft 58 is o eratively connected with he double b v l gear 51s by means of a bevel pinion BI and a clutch 62 having an opera-tins lev r 53, an the shaft 59 is similarly connected by means of a bevel pinion 64 and a clutch .65 having an op rating lever 66. .A- half nu 51 is al o provided, such nut being normally in threaded en gagement with the screw shaft 58 and having forked-arms .68 which receive and are slidable along the splined shaft 5.8, Disposed between and icurnaled in the arms .68 and keyed to the splined shaft 58 is a friction roller 69 engaging a friction plate 1.0, secured to the adjacent spud It will be se n that. as the p s operates at.

say, normal printing speed, the friction roller 6% will be rot ted eta constant angular velocity and that it will be fed inwardly and uniformly from the periphery of the friction plate toward the center of the roll 15. The rotary speed of the friction roller relatively to the speed of the press is determined by the gear ratio between the shafts 55 and 58 and will be constant for any given press speed. The pitch of the screw shaft .59 is such that the friction roller is fed inwardly at the same rate as the rate of diminution of diameter of the roll l5. When the roller 89 has been fed inwardly to its limit or as far as desired, the half nut 61 is lifted free of the shaft 59 and the roller is pushed back to its starting position.

It is thus apparent that a means has been provided of constantly adjusting the angular velocity of the roll to accommodate the same not only to various press speeds but also to the diameter of the roll. Thus, assuming operation at constant press speed, obviously as the roll is exhausted and the diameter decreases, if it is driven at the same angular velocity the linear velocity of the web unwinding from the roll will decrease and greater tension will be applied to the web until finally the web would break. In prior devices for adjusting the angular speed of the roll, straps have been used which travel at the linear speed of the press. The attendant disadvantages have been discussed hereinabove, and these disadvantages are in large measure obviated by the drive mechanism described.

It will be noted that the mechanical connection between the drive shaft 55 and the shafts 58 and 59 is such as not to interfere with rotation of the reel. Thus, when it is desired to rotate the reel 120 so as to bring a full roll up to normal operating position, this may be done without interrupting the driving connection between the shafts 55 and 58. It will also be noted that a clutch is provided for each of the shafts 58 and 59, and, therefore, that an idle pair of shafts 58, 59 may be disengaged and inactivated by means of the clutch levers 63 and 66. Also, just before pasting the end of a full roll to the web of a nearly exhausted roll, the full roll may be brought up to press speed by engaging its clutches 62 and 65.

It will therefore be apparent that means have been provided for controlling the operation of a reel for feeding a web to a high speed rotary press, and that such means maintain a proper, predetermined tension on the roll, brake the roll and bring it quickly to a stop when the circuit of the press motor is opened and provide a variable drive for the roll which ensures uniform linear speed of the web at any press speed and regardless of the diameter of the roll.

While I have shown the preferred form of my invention, it is to be understood that-various changes may be made in its construction by those skilled in the art without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a press assembly comprising a rotary press, an electric motor for operating the press, a main circuit for said motor and a rotatable reel for supporting a roll of newsprint or the like for the press, the improvement which comprises means for braking said roll, electrical means for actuating said braking means and a circuit for said electrical means, said circuit including said motor and being energized by the momentum of said motor when its main circuit has been broken.

2. A press assembly comprising a rotary press, a motor for operating said press, said motor having a main circuit for energizing and driving the motor and a shunt circuit which is energized by the motor when the main circuit is broken, a rotatable reel for supporting a roll of newsprint or the like, means for braking the roll and electrical means included in said shunt circuit for actuating said braking means when said main circuit is broken.

3. A press assembly comprising: a rotary press; a motor for operating said press, said motor having a constantly energized field, a main circuit connected to a source of power and the motor, a shunt circuit for the motor; a rota-table reel for supporting a roll of newsprint or the like; means for braking said reel; and electrical means for actuating said braking means, said electrical means being included in said shunt circuit and being energized by current generated in said circuit by the momentum of said motor in said field when said main circuit is broken.

4. A press assembly comprising: a rotary press; a motor for operating said press, said motor having a constantly energized field, a main circuit connected to a source of power and the motor, a shunt circuit for the motor; a rotatable reel for supporting a roll of newsprint or the like; means for braking said reel; and a solenoid for actuating said braking means, said solenoid being included in said shunt circuit and being energized by current generated in said circuit by the momentum of said motor in said field when said main circuit is broken.

5. A press assembly comprising: a rotary press, a motor for operating said press, said motor having a main circuit for energizing and driving the motor and a shunt circuit which is energized by the motor when the main circuit is broken; a rotatable reel for supporting a roll of newsprint or the like; hydraulic means for braking the roll; and electrical means included in said shunt circuit for actuating said hydraulic means when said main circuit is broken.

6. A press assembly comprising a main motor for operating the press at high speed and having a main circuit and a shunt circuit which is energized by said motor when said main circuit is broken, an auxiliary motor for operating the press at low speed and having a circuit, a rotatable reel for supporting a roll of newsprint or the like, means for braking said reel, electrical means energized by said shunt circuit for actuating said braking means, and electrical means energized by said auxiliary motor circuit for opposing said braking means.

GEORGE E. WHELDON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,664,640 Post Apr. 3, 1928 1,879,591 Taylor et al. Sept. 27, 1932 2,048,764 Wood July 28, 1936 2,232,252 Mathey Feb. 18, 1941 2,267,852 Walker Dec. 30, 1941 2,278,182 Lundquist et al. Mar. 31, 1942 2,437,128 Rieber Mar. 2, 1948 2,469,706 Winther May 10, 1949 2,474,620 Fath June 28, 1949

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