US3831876A

US3831876A - Continuous unwinding apparatus for web material

Info

Publication number: US3831876A
Application number: US00314142A
Authority: US
Inventors: R Phelps; R Tetro
Original assignee: Black Clawson Co
Current assignee: Black Clawson Co
Priority date: 1972-12-11
Filing date: 1972-12-11
Publication date: 1974-08-27
Anticipated expiration: 1991-08-27
Also published as: JPS5730775B2; JPS4987957A; IT996450B; CA1003810A; DE2361252A1; FR2210183A5; GB1458384A

Abstract

Continuous unwinding apparatus for web material comprises a pair of opposed end stands, each of which carries a pair of rollcarrying arms mounted for independent rotation on a common axis, and a splicer assembly is mounted for adjusting movement with respect to the end stands to accommodate rolls of definite diameters. There is no center shaft between the end stands, but separate drives couple opposed pairs of arms and provide for driving each coupled pair in either direction in any desired speed. An outstanding characteristic of the apparatus is that the movements of each pair of arms between splicing and final unwinding positions are confined to two quadrants of rotation.

Description

nited States Patent [19] Q Phelps et a]. I

m] 3,831,876 Aug. 27, 1974 CONTINUOUS UNWINDING APPARATUS FOR WEB MATERIAL Tetro, both of Fulton, N.Y.

Assignee: The Black Clawson Company,

Middletown, Ohio Dec. 11, 1972 U.S. Cl 242/583, 242/56 Int. Cl. B65h 19/14 Field of Search 242/583, 58.2, 58.4, 56

- References Cited UNITED STATES- PATENTS 2/1969 9/1963 6/ 1967 6/ 1967 Huck Huck Blessing Anderson 242/583 T Primary ExaminerJohn W. Huckert Assistant ExaminerEdward J. McCarthy Attorney, Agent, or FirmBiebel, French & Bugg ABSTRACT Continuous unwinding apparatus for web material comprises a pair of opposed end stands, each of which carries a pair of roll-carrying arms mounted for independent rotation on a common axis, and a splicer assembly is mounted for adjusting movement with respect to the end stands to accommodate rolls of definite diameters. There is no center shaft between the end stands, but separate drives couple opposed pairs of arms and provide for driving each coupled pair in either direction in any desired speed. An outstanding characteristic of the apparatus is that the movements of each pair of arms between splicing and final unwinding positions are confined to two quadrants of rotation.

9 Claims, 14 Drawing Figures I I l I 'r1' 8' r1 4: 1 T 5 :1. II I I L? Li, is 15% 45" ..34 124 I M *1 /Z' I W- BACKGROUND OF THE INVENTION In any process line for using or otherwise operating on paper or other continuous web material, there is at least one fixed station where pull rolls or other web drive means cause the web to travel from an up stream source to a downstream work station. Commonly the tension of the web is continuously measured between its source and the drive means to provide a control factor for the speed of the drive means.

It has been common for many years to utilize, as the supply source for such a line, unwinding apparatus which comprises a reel having two or more arms at opposite ends of a main shaft. In use, each opposed pair of reel arms successively receives a roll of web material to be unwound, and the reel is indexed to advance each pair of arms from a station where the expiring roll is unloaded and replaced with a full roll to a main unwinding station adjacent the next station in the process line. Continuous unwinding is provided by a splicing mechanism at or near the main unwinding station for severing the web from an expired roll and splicing the resulting web tail to the leading end of the web on a new roll.

Such reels are generally satisfactory for handling paper and other web material of relatively low elasticity and resistance to stretching. They have definite disadvantages, however, for handling web material, such as plastic, having significant plastic memory, and they are particularly unsatisfactory for handling relatively limp plastics which are easily stretched but have low ability to recover from stretching.

A major reason for these disadvantages is best explained in connection with a two-arm continuous unwinder. Since the arms are 180 removed from each other on the reel, the unwinding and reloading positions for each roll are similarly on opposite sides of the reel. Each successive expiring roll must therefore move through a substantial angular portion, approaching 180, of rotation of the roll from its main unwinding position in preparation for splicing.

During such movement, there is a considerable increase on the length of draw of the web from the expiring roll, and also the tension of that portion of the web tends to increase if the surface speed of the roll remains relatively constant. Further, since the expiring roll and the new roll are in relatively fixed position in the reel, each must take part in all indexing movement for the other, including the final indexing movement of the new roll as it is spliced to the web from the expiring roll. The ultimate result of these movement, coupled with the efforts of the tension control mechanism to correct for them, can seriously affect the operations of the rest of the process line and the product produced thereon.

An additional complication resulting from the conditions outlined above is related to the variation in length of the portion of web between each expiring roll and the nearest supporting or guide roll in the line. If the web is paper of adequate strength and resistance to streching, it may be able to support itself satisfactorily, but serious problems of sagging and localized stretching can occur if the web material is a limp plastic. In addition, such local sagging can further complicate the efforts of the tension control means to maintain constant tension conditions along the process line.

SY OF THE INVENTION The present invention has as its primary objective the provision of continuous unwinding apparatus which will be free of the above outlined disadvantages. It accomplishes this objective by a reel construction comprising a pair of opposed end stands each of which carries two roll supporting arms mounted for rotation on a common axis through 360 in both directions. These arms are coupled in opposed pairs by individually operable drive means such that each coupled pair can be rotated at any selected speed with respect to and independently of the other pair.

This construction of the reel and its drive means make it possible to carry on all of the essential functions of loading, splicing, unwinding and unloading in only two of the four quadrants of rotation of the paired reel arms, with the other two quadrants being used only for rotation of each successive unloaded pair of arms to loading position. The invention also makes available each and all of the following practical advantages over conventional continuous unwinding apparatus:

a. Decreased change in the web path during indexing.

b. Decreased change in the length of draw of the web during splicing.

c. Decreased requirements of indexing speed for completion of each cycle, which in turn contributes to accurately timed acceleration and deceleration of the rolls.

d. No indexing movement of the expiring rell during indexing of the full roll to splicing position.

e. Easy adjustment for accommodation of rolls of different sizes.

f. Easy change to present either the inner or the outer surface of the web uppermost in the process line.

In the preferred construction in accordance with the invention, each of the end stands assemblies is a duplicate of the other but is physically separate therefrom except for the drawing connections between corresponding components parts. There is no common shaft on the axis of the opposed reel arms, so that the center and one side of the apparatus is essentially open at all times, and this side is directed toward the associated process line. The splicing mechanism is mounted for movement between the reel and the rest of the process line so that it can enter the open space between the end stands and thereby position the pressure and guide rolls which are component parts thereof in close proximity to the successive rolls from which they receive the web. Similan'ly, the splicing mechanism can be adjusted toward and away from the reel as required for optimum results with rolls of different diameters.

These and other advantages, and the means by which they are achieved, will be apparent from the detailed description which follows in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a plan view of continuous unwinding apparatus in accordance with the invention, with no roll carried by either pair of arms;

FIG. 2 is an elevation of the apparatus of FIG. 1 looking from left to right in FIG. 3;

FIG. 3 is an elevation looking from right to left in FIG. 2 and showing the apparatus with one roll unwinding and a full roll ready to be unwound;

FIG. 4 is an enlarged fragmentary section on the line 4-4 of FIG. 1;

FIG. 5 is an enlarged fragmentary section on the line 5-5 of FIG. 1',

FIG. 6 is a view looking in the same direction as FIG. 3 and showing the splicer assembly in two relatively moved positions;

FIGS. 7-11) are semi-diagrammatic views illustrating successive stages of unwinding and under splicing with the apparatus of FIGS. 1-6; and

FIGS. 11-14 are views similar to FIGS. 7-10 illustrating successive stages of unwinding and over splicing with the apparatus of FIGS. 1-6.

DESCRIPTION OF THE PREFERRED EMBODIMENT The unwinding apparatus shown in the drawings comprises two essential identical end stand and driving assemblies mounted at opposite ends of a common base 10. The assembly at the right-hand end of FIGS. 1 and 2 comprises a gear case 11 in which are mounted two

roll supporting arms

12 and 13 of the same radial dimensions. The arm 12 is straight, but arm 13 axially offset so that its radially outer end portion is aligned with arm 12, and the two arms are mounted for independent rotation in either direction. As shown in FIG. 4, arm 12 has a straight supporting shaft 15 provided with a worm gear 16 at its outer end, and arm 13 is carried by a hollow shaft 17 which surrounds shaft 15 and carries a similar worm gear 18.

The end stand assembly at the opposite end of base comprises a gear case 21 of the same construction as gear case 11 in which are mounted two arms 12 and 13' identical with the

arms

12 and 13 respectively and similarly mounted for rotation on the same axis 22 as arms 12-13. The straight arm 12 is carried by a straight hollow shaft 25 having a worm gear 26 at its outer end, and the offset arm 13 is carried by a hollow shaft 27 concentric with and partially enclosing shaft 25 and also provided with a worm gear 28. Opposed pairs of dissimilar arms are coupled by driving connections causing each pair to operate as a unit.

The drive for the paired arms 12 and 13' comprises 'a motor 30 in housing 31 which drives arm shaft through a transmission 32, universal connection 33 and worm 34. The shaft 35 extends from transmission 32 to a similar transmission 36 in housing 37 from which it is transmitted through the universal connection 38 to a worm 39 driving gear 28. Similarly the drive for

arms

12 and 13 comprises a motor (not shown) in housing 37 which drives arm shaft through a transmission 42, universal connection 43 and worm 44 driving gear 26. The same drive is transmitted through the shaft 45 to a transmission 46 in housing 31 and then in turn through the universal connection 48 to a worm 49 driving gear 18.

Each of arms 12-13 and 12'-13 is provided with a spindle for holding one end of a shaft or core supporting a roll to be unwound, and each pair of spindles is provided with a drive for controlling its rotational speed to maintain proper tension in the unwinding web. Referring to FIG. 4, the arm 12 carries a spindle 511 keyed at 51 in a sleeve 52 rotatable in the outer end of the arm. The drive motor 55 for spindle 511 is mounted on the housing 31 beside end stand 11 and is connected through a belt drive 54 with the drive spindle 56 which extends through the shaft 15 supporting arm 12. -A drive sprocket 57 on the inner end of spindle 56 drives sprocket 58 on sleeve 52 through a suitable drive chain 59.

The spindle 59 is also mounted for axial movement in arm 12 for loading and unloading purposes. As shown in FIG. 5, spindle 511 is axially movable in the sleeve 52, and this movement is effected by an air motor 611 connected through gears 61-62 to a lead screw 63 operating a thrust nut 65. A collar 66 connects the ends of nut 65 and spindle 511 so that axial movement of the nut in response to rotation of lead screw 63 causes corresponding axial movement of spindle 511. The drives for spindle 511 are duplicated for the corresponding spindle 50 in arm 12' as indicated by the motor 55 on housing 37.

The core spindle 70 in arm 13 which is paired with spindle 50 is aligned with spindle 511 and accordingly needs no drive control, but it is provided with an axial drive for loading and unloading purposes. Referring to FIG. 5, an air motor 72 has a driving connection through gears 73-74 to lead screw 75, and the thrust nut 76 driven by lead screw is connected by collar 77 with the other end of spindle 70. This construction is duplicated for the spindle 70' in arm 13'.

As best seen in FIG. 1, the construction and arrangement of the end stand and drive assemblies makes it possible to leave one side of the apparatus essentially open, and the splicer assembly is mounted for adjusting movement in this space. Referring to FIGS. 1-3 and 6, the splicer assembly comprises a pair of complementary end frames 91) and 91 mounted for sliding movement on base 10 with the aid of gibs and guides indicated generally at 92. As described hereinafter, the movement of the frame -91 is for the purpose of adjustment to handle rolls of different sizes, and it is effected and controlled by a drive motor 95 operating a pair of screw jacks 96 through a cross shaft 97.

The main operating components of the splicer assembly comprise the knife 1011, two paster rolls 1111-102, and two guide rolls 1113 and 1114. The paster rolls are used alternatively depending on whether the inside or outside of the web being unwound is to be presented uppermost to the process line. Each paster roll is mounted at each end by a lever pivoted at 1116 on the associated frame 911 or 91 and biased against swinging movement in one direction by an air cylinder 1117 or other suitable biasing means.

The knife 11111 is carried by a rack shaft mounted in the frames 911-91 and provided at each end with a pinion 111 meshing with a rack 112 mounted for longitudinal reciprocation in the frame by an air cylinder 115 assembly which is selectively operable in either direction and includes shock absorbing springs 116. Knife 11111 is selectively operated in either direction depending upon whether the process line calls for over splicing (the inside of the web uppermost) or under splicing (the outside of the web uppermost). It is shown as arranged for under splicing, with the rack 112 fully advanced so that firing of cylinder 115 will cause the rack to retract and the knife to swing counterclockwise.

FIGS. 3 and 7-1@ show the operating sequence for under splicing. In FIG. 3, the roll 12% is supported in its final unwinding position by arm 12 and its complementary arm 13, with the web wrapping the underside of paster roll 102 and the upper side of guide roll 103, and the new roll 121 has already been loaded in

arms

13 and 12. Unwinding continues without requiring movement of either pair of arms from the positions shown in FIG. 3, but during this interval, roll 121 should be prepared for splicing, as by the application of adhesive or other conventional procedure.

When roll 120 is almost completely unwound, the drive to spindle 50' is actuated to bring the surface speed of roll 121 up to that of the web unwinding from roll 120, and arms 12'-13 are indexed counterclockwise until the surface of roll 121 is pressed against the web wrapping paster roll 102, as shown in FIG. 7. At the same instant, cylinders 115 are fired to drive knife 100 through its cutting cycle wherein it severs the web between roll 120 and paster roll 102, as shown in FIG. 7. If the size of the core and the geometry of the system requires that arms 12-13 move past 12:00 clock to assure that the expiring web is adequately within the stroke of the knife, the arms are indexed accordingly as a part of the splicing sequence. Immediately following splicing, the arms 12'-13 are indexed clockwise sufficiently to establish clearance between the surface of roll 121 and paster roll 102 as unwinding continues from roll 121 in the position of the parts shown in FIG. 8.

As soon as roll 121 begins to unwind, the expired roll and supporting core are removed from 12-13, which may be done with those arms at any convenient position in the angular range shown in FIG. 9. Both pairs of arms can then be rotated clock-wise to the reverse of their positions shown in FIG. 3, but arms 12-13 carrying the unwinding roll 121 require movement of considerably less than 180, while the empty arms 12-13' will move closer to 240. A new roll can then be loaded in arms 12-13', to reestablish the conditions shown in FIG. 3, as soon as roll 121 has unwound sufficiently to provide space for the new roll, for example to a diameter of 24 inches if its initial diameter was 40 inches, and for smaller rolls, reloading can be done substantially immediately.

It is apparent from the description of the operating sequence and FIGS. 3 and 7-10 that the essential operations of loading, unwinding, splicing and reloading take place in less than 180 of the total rotational movement of each pair of arms, and essentially in the two quadrants of arm rotation which lie on the opposite side of the common axis 22 of the arms from the splicer assembly and the direction in which the web travels from the apparatus. In fact, the total movement of each pair of arms from splicing position to severing position is substantially less than 180 and need not exceed approximately 150 even for rolls of the maximum diameter which the apparatus is designed to handle.

Two important advantages result from this twoquadrant feature. One is that the total change in the length of draw from the unwinding roll to the paster roll 102 is relatively small, and notably less than is required with a conventional reel having its arms fixed on a common shaft. For example, with the apparatus constructed as disclosed to handle 40-inch rolls, if a partially unwound roll 120 were moved from the position of FIG. 11 to that of FIG. 12 without interim unwinding, the difference in the length of draw would be only about 1 foot. Further, the movement of arms 12-13 between the limit positions they occupy during unwinding can be at a relatively low rate such that any variation in the length of draw resulting from the movement does not affect the tension in the web, and they remain stationary during the movement of arms 12-13 incident to splicing. The empty pair of arms, however, can be moved at any desired different speed without in any way affecting web tension or the position of the unwinding roll.

For optimum results in the use of the invention, the several drive motors should be controlled by automatic circuit means, in accordance with common practice in the web winding and unwinding art. No specfic disclosure of control means has therefore been included herein, since it will be apparent to those skilled in the art ahow to control the drives in such manner as to achieve the results described herein. how

The dotted line showings in FIG. 6 illustrate how the splicer assembly can be adjusted to accommodate rolls 125 of the minimum diameter for which the apparatus is designed, e.g. 14 inches. It will be seen that in this adjusted position, the knife 100 and paster rolls 101 and 102 lie on the same side of arm axis 22 as the arms and the unwinding rolls. FIG. 6 also shows that the arms holding a 14-inch roll in splicing position are at an angle of only approximately 35 to the horizontal, and they need not move beyond the corresponding angle above the horizontal, so that their total movement during unwinding will not exceed approximately Correspondingly changed conditions are established in intermediate adjusted positions of the splicer assembly and for rolls of intermediate diameters.

FIGS. 111-14 show the operating sequence for over splicing, wherein the inner surface of the web is presented uppermost to the process line. FIG. 11 shows the parts in the relative positions which correspond to FIG. 3, with arms 12 and 13' positioned at approximately 6 oclock to support 130 in its final unwinding position, with the web wrapping the uppersizde of paster roll 101 and the underside of guide roll 103, and with a new roll 131 already loaded in arms 12-13 in approximately 10 oclock position. FIG. 14 shows the parts in splicing position corresponding to FIG. 8, with arms 12-13 moved slightly beyond 6 oclock, and with arms 12-13 moved to approximately 11 oclock to press roll 131 against the portion of the web running over paster roll 101. These views also show that for over splicing, the rest position of knife is reversed from FIGS. 3 and t1, and its operating stroke is counterclockwise.

As described in connection with under splicing, arms 12'-13 are indexed to move roll 131 away from paster roll 101 as soon as splicing is accomplished. FIG. 13 shows roll 131 in the resulting initial unwinding position, and also illustrates the angular range for unloading of arms 12-13. FIG. 14 corresponds to FIG. 10 and shows arms 12-13 moved to hold roll 131 in its final unwinding range of positions, and it also shows arms 12-13 ready for reloading with a full roll. It is apparent that the operating sequence illustrated by FIGS. 11-14 offers the same advantages of two-quadrant operation already described for under splicing, and that this applies to the handling of all sizes of rolls within the range for which the apparatus is designed and for all correspondingly adjusted positions of the splicer assembly.

It should also be noted that although the invention has been illustrated by an embodiment wherein the two quadrants within which the operations occur lie on one side of a vertical reference line through the axis about which the roll arms rotate, this is primarily because such an arrangement is convenient for many applications of the invention. it will be readily apparent from FIGS. 7-14, however, that practice of the invention is not limited to this particular arrangement, and that the reference line can be rotated to any other desired position, which requires only that the splicer assembly be correspondingly relocated.

While the method herein described, and the apparatus for carrying this method into effect, constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to this precise method and apparatus, and that changes may be made in either without departing from the scope of the invention.

What is claimed is:

1. Apparatus for continously unwinding web material from successive rolls, comprising:

a. a pair of spaced opposed end stands,

b. two roll supporting arms mounted for rotation on a common axis through 360 in both directions in each of said end stands,

c. means coupling said arms in opposed pairs,

(1. means establishing a first unwinding position for a roll supported by either of said pairs of arms in a first quadrant of said rotation thereof,

means establishing a final unwinding position for a roll supported by either of said pairs of arms which lies in a second quadrant of said rotation thereof contiguous to said first quadrant and therefore requires less than 180 rotation of said arms from said first winding position,

f. means establishing a splicing position for each said pair of arms in said first quadrant wherein the web from a roll supported by one of said pairs of arms in said final unwinding position is spliced to the end of the web on a new roll supported by the other said pair of arms, and

g. means for selectively driving each said coupled pair of arms in either direction with respect to and independently of the other said pair to provide for rotation of each said pair successively from said first unwinding position to said final unwinding position at predetermined controlled speed contemporaneously with unloading and loading of the other said pair with a new roll and rotation thereof from said final unwinding position to said splicing position through the other two quadrants of said rotation of said arms.

2. Apparatus as defined in claim ll wherein both of said first and second quadrants lie on one side of said axis, and further comprising guide means for conducting the web material from a roll supported in either of said quadrants in a direction extending initially generally laterally from said axis on the opposite side thereof from said first and second quadrants.

3. Apparatus as defined in claim ll wherein both of said first and second quadrants lie on one side of said axis, and further comprising splicer assembly means mounted on the opposite side of said axis and including means for effecting severing of the web unwinding from an expiring roll supported in said final unwinding position and means for splicing said severed web to the end of the web on a new roll supported in said splicing position.

4. Apparatus as defined in claim 3 wherein said splicer assembly means comprises,

a. a pair of paster rolls selectively engageable with the web unwinding from an expiring roll supported 5 in said final unwinding position to press said web into splicing contact with a new roll supported in said splicing position, and b. knife means selectively operable to sever such web at a position between said expiring and new rolls.

l 5. Apparatus as defined in claim 4 further comprising means supporting said splicer assembly means for movement towards and away from said axis in accordance with the diameter of each such new roll.

6. Apparatus as defined in claim 5 wherein all connections between said end stands are located outside the projection of the circular paths traversed by the outer ends of said arms to provide for movement of said splicer assembly means into the space between said end stands defined by said projected paths and correspondingly short travel of the web from an unwinding roll to the selected said pressure roll.

7. Apparatus as defined in claim 1 wherein both of said first and second quadrants lie on one side of a vertical center line through said axis, and further comprising splicer assembly means mounted on the opposite side of said center line and including means for effecting severing of the web unwinding from an expiring roll supported in said final unwinding position and means for splicing said severed web to the end of the web on a new roll supported in said splicing position.

8. In a method of continuously unwinding web material from successive rolls in apparatus including two pairs of opposed roll supporting arms mounted independently of each other on a common axis through 360 in both directions, the steps comprising:

a. unwinding an initial portion of the web from a roll supported by one of said pairs of arms in a first unwinding position located in a first quadrant of said rotation of said arms,

b. rotating said one pair of arms at predetermined controlled speed from said first winding position through less than 180 to a final unwinding position located in a second quadrant of said rotation contiguous to said first quadrant while continuing said unwinding operation,

c. contemporaneously with said rotating step (b), ro-

tating said other pair of arms to said first quadrant and then loading a new roll thereon,

d. splicing the web from the resulting expired roll in said one pair of arms to the end of the web on said new roll while retaining said other pair of arms in said first quadrant,

e. unloading said expired roll from said one pair of arms,

f. performing said unwinding step (a) and rotating step (b) with respect to said new roll and said other 55 pair of arms,

g. rotating said unloaded pair of arms through the other two quadrants to said first quadrant in timed relation with said rotating step (b) of said other pair of arms; and

h. repeating all of said steps for successive new rolls.

side thereof from said quadrants.

# fl= 2: t

Claims

1. Apparatus for continously unwinding web material from successive rolls, comprising: a. a pair of spaced opposed end stands, b. two roll supporting arms mounted for rotation on a common axis through 360* in both directions in each of said end stands, c. means coupling said arms in opposed pairs, d. means establishing a first unwinding position for a roll supported by either of said pairs of arms in a first quadrant of said rotation thereof, e. means establishing a final unwinding position for a roll supported by either of said pairs of arms which lies in a second quadrant of said rotation thereof contiguous to said first quadrant and therefore requires less than 180* rotation of said arms from said first winding position, f. means establishing a splicing position for each said pair of arms in said first quadrant wherein the web from a roll supported by one of said pairs of arms in said final unwinding position is spliced to the end of the web on a new roll supported by the other said pair of arms, and g. means for selectively driving each said coupled pair of arms in either direction with respect to and independently of the other said pair to provide for rotation of each said pair successively from said first unwinding position to said final unwinding position at predetermined controlled sPeed contemporaneously with unloading and loading of the other said pair with a new roll and rotation thereof from said final unwinding position to said splicing position through the other two quadrants of said rotation of said arms.

2. Apparatus as defined in claim 1 wherein both of said first and second quadrants lie on one side of said axis, and further comprising guide means for conducting the web material from a roll supported in either of said quadrants in a direction extending initially generally laterally from said axis on the opposite side thereof from said first and second quadrants.

3. Apparatus as defined in claim 1 wherein both of said first and second quadrants lie on one side of said axis, and further comprising splicer assembly means mounted on the opposite side of said axis and including means for effecting severing of the web unwinding from an expiring roll supported in said final unwinding position and means for splicing said severed web to the end of the web on a new roll supported in said splicing position.

4. Apparatus as defined in claim 3 wherein said splicer assembly means comprises, a. a pair of paster rolls selectively engageable with the web unwinding from an expiring roll supported in said final unwinding position to press said web into splicing contact with a new roll supported in said splicing position, and b. knife means selectively operable to sever such web at a position between said expiring and new rolls.

5. Apparatus as defined in claim 4 further comprising means supporting said splicer assembly means for movement towards and away from said axis in accordance with the diameter of each such new roll.

8. In a method of continuously unwinding web material from successive rolls in apparatus including two pairs of opposed roll supporting arms mounted independently of each other on a common axis through 360* in both directions, the steps comprising: a. unwinding an initial portion of the web from a roll supported by one of said pairs of arms in a first unwinding position located in a first quadrant of said rotation of said arms, b. rotating said one pair of arms at predetermined controlled speed from said first winding position through less than 180* to a final unwinding position located in a second quadrant of said rotation contiguous to said first quadrant while continuing said unwinding operation, c. contemporaneously with said rotating step (b), rotating said other pair of arms to said first quadrant and then loading a new roll thereon, d. splicing the web from the resulting expired roll in said one pair of arms to the end of the web on said new roll while retaining said other pair of arms in said first quadrant, e. unloading said expired roll from said one pair of arms, f. performing said unwinding step (a) and rotating step (b) with respect to said new roll and said other pair of arms, g. rotating said unloaded pair of arms through the other two quadrants to said first quadrant in timed relation with said rotating step (b) of said other pair of arms; and h. repeatinG all of said steps for successive new rolls.

9. The method defined in claim 8 wherein both of said first and second quadrants lie on one side of a vertical center line through said axis, and wherein said web is guided away from said apparatus in a direction extending generally laterally of said axis on the opposite side thereof from said quadrants.