US 2947057 A
Description (OCR text may contain errors)
1950 .J. MEAGHER, JR ErAL 2,947,057
FLEXIBLE WEB REELING AND GUIDING MECHANISMS Filed Feb.- s, 1956 United States Patcnt O FLEXIBLE WEB REELING AND GUIDING MECHANISMS James L. Meagher, Jr., Rogers, and Edward A. Baril, Plainfield, Conn., assignors, by mesne assignments, to Plainfield Patents Corporation, Plainfield, Conn., a corporation of Delaware Filed Feb. 3, 1956, Ser. No. 563,30
1 Claim. (Cl. 26-66) This invention relates to web reeling mechanisms and more especially to the reeling or winding of flexible webs.
A principal object of the invention is to provide novel mechanism for reeling or winding flexible webs which are subject to dimensional distortion in mutually perpen dicular directions.
Another object is to provide a reeling or winding mechanism for controlling the linear feeding movement of a flexible web to maintain the web in predetermined alignment with respect to a winding reel or the like, while also protecting the web against width distortion and wrinkle formation and without maintaining the web under continuous tension.
A feature of the invention relates to an automatic control for the linearizing and width of a flexible web during its movement between two different points, for example between an unwinding roll and a winding roll, and particularly without subjecting theweb to any substantial tension throughout its length.
Another feature relates to a novel automatic linearizing and automatic width control device for flexible web feeding mechanisms.
winding roll, is not too great where reliance can be placed upon substantial and continuous tension in the web to maintain it linearly taut. terial is not subject to any substantial lateral or width distortion during feeding movement, conventional alignment controls can be used. However, we have found that where both conditions must be met, namely extremely low tension in the web and freedom from the likelihood of width distortion, it is necessary to employ a special form of feeding and width control which constitutes the present invention.
Accordingly, in the drawing the numeral 10 represents an unwinding roll carrying the supply of the readily A further feature relates to a dual photoelectric control 7 automatic linearizing and automatic width control for flexible web feeding mechanisms and the like.
A still further feature relates to the novel organization, arrangement and relative location and interconnection of parts which cooperate to provide an improved reeling mechanism for flexible webs.
Other features and advantages, not particularly enumerated, will appear from the ensuing descriptions, the appended claim, and the attached drawings.
In the drawing, which shows one preferred exemplification,
Fig. l is a top plan view of a web feeding mechanism embodying the invention;
Fig. 2 is a sectional view of Fig. 1 taken along the line 2-2 thereof;
Fig. 3 is a schematic wiring diagram of the control circuits used with the mechanism of Fig. 1;
Fig. 4 is a schematic view of the web and photoelectric controls. 7
Various kinds of web feeding and control devices have been proposed heretofore and have been found successful in controlling the feeding movement of certain kinds of webs. However, when the webs are constituted of a very flexible material which is readily distorable in length and width even when subjected to relatively low tensions, such conventional control devices have not always been found satisfactory. This is especially true where the web is in the form of a light weight, soft, stretchable, knit fabric, or in the form of a rubber-like or readily extensible film, such as vinyl plastic film and the like. It has been found necessary with such materials to make sure that they are subjected to the very minimum amount of tension during the feeding movement. The problem of linearizing the travel of relatively non-stretchable webs between two points, for example between an unwinding roll and a stretchable and flexible material 11, which material is arranged to be wound on a receiving roll 12 located at a substantial distance from roll 10. Roll 12 is positively driven at the required winding speed by a suitable motor 13, which may be the common drive motor for the entire machine, and the roll 10 is supported on suitable bearings so that the web 11 is subjected to minimum tension, namely a tension which does not produce any substantial longitudinal or lateral distortion of the web. However, for various reasons, it has not been found feasible to wind a stretchable web in the proper non-offset relation on roll 12 without some form of automatic linearizing and width control in the region where the web is about to be wound on the roll 12. Furthermore, it is not only necessary to make sure that the path of travel of the web in the winding region adjacent the roll 12 is perpendicular to the axis of the roll rotation, but it is also necessary that the actual width of the web at the winding region remains uniform. This latter problem, of course, is not encountered with ordinary non-stretchable webs. It will be understood, of course, that the web may pass through one or more processing devices (not shown) between the roll 10 and the roll 12 and the rewinding power is supplied entirely by the motor 13. Furthermore, the web 11 may be supported on any smooth surfaced plates or supports between the rolls 10 and 12 so as to exert negligible drag on the web.
For the above purposes, the opposite longitudinal marginal portions of web 11 pass between respective pairs of control rollers 14, 15 and 16, 17. The upper roller of each pair, namely rollers 14 and 16, are preferably of metal such as aluminum, while the lower rollers of each pair are preferably of rubber. The metal rollers 14 and 16 are positively driven in the direction of the arrows so as to tend to assist the movement of the web from right to left, as seen in Fig. 1 of the drawing. The rollers 14 and 16 are driven in fixed speed relation to the speed of roll 12 so that the web is not subjected to any substantial longitudinal tension in the region between the roll 12 and the control rollers. For example, rollers 14 and 16 may have their respective shafts driven through respective bevel gear trains 18, 19 "from the common cross shaft 20, which in turn is driven for example by a chain or belt drive 21 from the motor shaft 22. It will be understood, of course, that the motor 13 should beconnected to the shaft 22 through any suitable speed changer so that the peripheral speed of the rollers 14 and 16 can beset at any predetermined ratio to that of any other units through which the web may pass after leaving the unwinding roll 10. Preferably the rollers 14, 15 and 16, 17 are carried on respective frames 23, 24, which are mounted for slidable adjustment towards and away from the web as indicated by the arrows in Fig. 2. The positively driven rollers 14 and 16 can be vertically adjusted on their respective frames so that they are both in engagement with the upper face of web 11. However, this Likewise, where the web maposition they do not subject the web to any traction. The Y rollers 15 and 17 are carried by respective vertically shiftable brackets 25, 26, these brackets being connected to respective plungers 27, 28 operated by respective pneumatic actuators 29, 30. Each actuator is connected through through a respective valve-controlled air line to a source of compressed air (not shown). For example, the actuator 30 is connected to air line 31 through a suitable valve 32, which is arranged to be controlled by the armature 33 of an electromagnet 34. Since these pneumatic control units are identical for both sets of rolls, only one control unit is shown in detail, namely that in Fig. 2, and its associated electric circuits are shown in Fig. 3. When the electromagnet 34 is deenergized, its armature 33 closes the valve 32, thus allowing the roller 17 to drop by a suitable spring loading (not shown) so that it is out of contact with the undersurface of web 11. On the other hand, when the electromagnet 34 is energized, the valve 32' is opened and the actuator 30 forces the roller 17 into contact with the lower.surface of the web. However, the roller 17 is not positively driven but since the web 11 is now in contact with the positively driven roller 16 and the roller 17, the web 11 is subject to traction by reason of its being nipped between the rollers.
For the purpose of controlling each of the pneumatic actuators, there is provided for each actuator a corresponding photoelectric cell 35, 36. These cells are positioned close to the respective longitudinal edges of the web 11, so that when the said web is traveling in the proper linear path, namely perpendicular to the axis of rotation of roll 12 and is not contracted laterally, both cells are blanked olf against light excitation and, therefore, their respective electromagnets 34 are deenergized. It will be understood, of course, that each photoelectric cell 35, 36 can be housed in suitable light tight housing schematically shown in Fig. 4 and with a suitable aperture through which it may be illuminated through a corresponding lamp or light source represented schematically in Fig. 4 by the numeral 37. In other words, web 11 acts as a blanking off shutter between each light source and its associated photoelectric cell.
It is clear, therefore, that as long as the web 11 is moving in the proper linear direction and as long as its width remains normal, neither of the cells is energized and, therefore, neither of the control units exerts any traction on the web. On the other hand, if for example the web should bodily shift its direction of travel laterally, as represented for example by the dot-dash lines in Fig. 1, one of the cells will be uncovered, for example cell 36, which will cause its associated electromagnet 34 to be energized, resulting in the vertical movement of its associated roller 17 thus exerting a traction on the corresponding margin of the web 11. The direction of this traction will, of course, be dependent upon the angular relation of the rollers 16 and 17 with respect to the web.
It will be understood, of course, that the said angular relation can be adjusted to any particular setting in any suitable manner. For example, the frames 23, 24, carrying the respective roller control units, may be turned at any desired angle so as to position the respective rollers in any desired angular relation with respect to the direction of travel of web 11. This angle of direction may be varied between degrees and 90 degrees. If, for example, the rollers of both control sets are positioned so as to be at 90 degrees with respect to the normal longitudinal direction of travel of the web, then of course even if their respective pneumatic actuators 30, 31 are operated, the rolls will exert a traction extending along the normal longitudinal direction of the web feed. If, however, the said sets of rollers are adjusted at less than 90 degrees, for example at an angle of 45 degrees with respect to the normal longitudinal Web motion, then when either of the pneumatic actuators is operated it causes the correspondingrollers to exert tractive force on the web, which force has a substantial sidewise component. In other words, the two sets of roller controls come into action upon various conditions of the web in the region where it is being wound upon roll 12. For example, if the two sets of control rollers are mounted at the same angle less than 90 degrees with respect to the web, if the web should shift bodily adjacent the winding region so as to uncover the cell 36 alone, then the actuator is operated and the rollers 16 and 17 exert a corresponding sidewise traction on the web of sufficient magnitude to restore the web to its proper linear winding relation. Under this condition, the rollers 14 and 15 are, of course, out of contact with the Web and the net result is that the web is shifted bodily, but without lateral stretching, to its proper winding path. It is quite clear, therefore, that if the web should shift bodily laterally in the opposite direction from that indicated by the dot-dash line in Fig. l, the cell takes control and the rollers 14 and 15 are brought into traction engagement with the web and shift the web bodily to the proper winding direction, whereupon both cells are deenergized and the correcting action is discontinued.
On the other hand, if for any reason the web should be subjected to any substantial tension, resulting in a contraction of its width at the winding region, both a linearizing and lateral stretching action would be produced. For example, if as a result of undesired tension on the web its width contractionshould be of sufficient magnitude to uncover both cells 35, 36, then both of the roller control units come into action and instead of shifting the web bodily in a lateral direction, both sets of rollers exert oppositely directed sidewise traction on the web, thus overcoming the tendency to contract. When the web at the winding region is restored to its proper normal width as a result of the removal of the undesired tension, then of course both of the sets of control rollers are taken out of action and the web proceeds to be rolled in the proper width.
The action of the mechanism is as follows. Let it be assumed that the web 11 is a light weight, soft, stretchable, knit fabric. The two sets of control rollers on opposite sides of the web can be adjusted at an angle of approximately 75 degrees to the desired direction of web travel, as illustrated in the drawing, it being understood, of course, that these sets of rollers are adjusted so that the marginal portions of the web are threaded between the corresponding pairs of rollers. The Web 11 is lined up in the proper direction, namely perpendicular to the axis of roll 12, and in this condition both of the cells 35 and 36 are blanked off. Therefore, the motor 13 drives the roll 12 at the required speed but no traction is effected on the web by the two sets of control rolls. Thus, the web is free to be reeled without any correction.
As the Web is pulled forward, to the left as shown in Fig. 1, by the roll 12, there is a tendency to subject the Web to a very slight tension. Ordinarily, this tension is insufficient to change the width of the web at the rewinding region. However, if for any reason there is appreciable drag on the web between the rolls 10 and 12, the web may narrow sufiiciently to unmask the cells 35 and 36. The nip which, therefore, results on the web between the two sets of control rollers causes the web to be stretched laterally at right angles to its axis of travel, and at the same time these rollers overcome tension on the web adjacent the winding roll 12, thus further reducing the tendency to narrowing of the web. As the web moves at right angles to its length, it masks both of the cells, thus lowering the rollers 15 and 17 and permitting the initial undesired narrowing effect of the web to be repeated. Although the right angle stretching effect or lateral movement of the web efiected by the angularly located control rollers may be as much as two inches, the said control rolls may be mounted so close to the rewind roll 12 that the tendency for the web to vary its width in an oscillatory manner can be dampened to as little as one-quarter inch or less by the arrangement described.
It will be understood, of course, that the invention is not limited to a horizontal movement of the web. The web may be moved in a vertical path or in an inclined path,.in which event, of course, the two sets of control rollers will be appropriately mounted to permit the web to pass therebetween. In order to facilitate angular adjustment of the rolls with respect to the web, suitable flexible shafts or universal couplings may be provided between the respective gear trains 18 and 19 and the rolls 15 and 16, it being understood that each set of these rolls, namely the set 14 and 15 and the set 16 and 17, are mounted for horizontal adjustment, vertical adjustment, and angular adjustment, the degree of the angular adjustment being determined mainly by the inherent stretchability of the web 11.
While one particular embodiment has been disclosed herein, it will be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention.
What is claimed is:
A web reeling control mechanism for a web which is extensible under tension and comprising, means to feed the web between two spaced points while maintaining the web under minimum tension which is insufiicient to cause substantial width distortion of the web, a first set of correction rollers mounted at an angle to and adjacent one margin of the web, a second set of correction rollers mounted at an angle to and adjacent the opposite margin of the web, the web passing between the rollers of each set, one roller of each set being positively power driven independently of the web motion and the other roller of each set being an idler roller, a support for each idler roller, means to operate each support to move its idler roller into and out of traction contact with the web only when the web width becomes distorted or while the web is moving in a path ofiset from a predetermined linear path, a pair of light-sensitive devices located respectively adjacent the said margins of the web and selectively masked or unmasked in accordance with the width and path of movement of the web, electric circuit connections between said cells and the said operating means for automatically controlling the movement of said idler rollers to correct width distortion of the web and to restore the movement of the web to said desired linear path, said support operating means including a pneumatic controlled member, and a valve for controlling said pneumatic member, said connections comprising circuit connections between each light-sensitive device and a corresponding one of said valve for selectively controlling the movement of the associated idler roller.
References Cited in the file of this patent UNITED STATES PATENTS 739,968 Wood et a1 Sept. 29, 1903 1,569,077 Durrant Jan. 12, 1926 1,769,687 Hamilton July 1, 1930 1,791,288 Schweitzer Feb. 3, 1931 1,875,777 T ackaberry Sept. 6, 1932 2,082,799 Hetherington June 8, 1937 2,188,665 Sperry July 30, 1940 2,752,657 Meneo July 3, 1956 FOREIGN PATENTS 414,776 Italy Aug. 24, 1946