US3765584A

US3765584A - Automatic web tension control

Info

Publication number: US3765584A
Application number: US00133066A
Authority: US
Inventors: E Rowe
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-04-12
Filing date: 1971-04-12
Publication date: 1973-10-16
Anticipated expiration: 1990-10-16
Also published as: CA963440A

Abstract

The web tension device includes a tension producer and tension sensor interconnected with controls. The tension sensor consists of a member loaded in one direction by a load cell and in the opposite direction by the tensed web. The position of the member is sensed by air escaping through a nozzle controlled by a ''''flapper'''' in a sensor arm. A plurality of bars actuated by an air cylinder produce the tension on the web through the interconnected controls. The control system utilizes air pressure supplied to the load cell through an orifice to an air relay and the sensor nozzle. Pressure not escaping from the nozzle is amplified in the relay which supplies air to the tension producing cylinder in the tension producer.

Description

United States Patent [191 Rowe [ 1 Oct. 16, 1973 AUTOMATIC WEB TENSION CONTROL [76] Inventor: E. Riley Rowe, Hartsville, S.C. [22] Filed: Apr. 12, 1971 [21] Appl. No.: 133,066

[52] U.S. Cl 226/39, 226/44, 226/45, 226/114 [51] Int. Cl B65h 25/04 [58] Field of Search 226/39, 44, 45, 113, 226/1 14 [56] References Cited UNITED STATES PATENTS 1,941,597 1/1934 Cavagnaro 226/114 3,032,245 I 5/1962 George 226/39 3,460,729 8/1969 Treff 226/44 Primary Examiner-Richard A. Schacher Attorney-C. Gordon McBride [57] ABSTRACT The web tension device includes a tension producer and tension sensor interconnected with controls. The tension sensor consists of a member loaded in one direction by a load cell and in the opposite direction by the tensed web. The position of the member is sensed by air escaping through a nozzle controlled by a flapper in a sensor arm. A plurality of bars actuated by an air cylinder produce the tension on the web through the interconnected controls. The control system utilizes air pressure supplied to the load cell through an orifice to an air relay and the sensor nozzle. Pressure not escaping from the nozzle is amplified in the relay which supplies air to the tension producing cylinder in the tension producer.

9 Claims, 6 Drawing Figures IO L 5 O 46 l is I8, \v E n \se/ 58 i-= 9g 20 I 4 92 64 i if 9" l k of! v 28 6O \\Y2\26 26 32 62 4 PAIENIEDHCI 16 m3 SHEET E OF 3 FIG. 4

INVENTOR.

E. RILEY ROWE c G R o g: RIDE ATTOfifi ,PATENIEDUBHSIHH I 3.765.584

- s m as? 3 INVENTOR. .E. RILEY" ROWE BY 0 GORDQN MoBRlDE 1 AUTOMATIC WEB TENSION CONTROL In the manufacture of various items in which a web is passed through some point at which it is wound or its direction is changed, there are various forces which cause breakage or an undesired tension or change of direction of the web. This is especially true in the manufacture of spiral tubes wherein a web of paper or fi-.

brous material is wound about a mandrel to produce a tubular article. Any requirement for the winding of a linearly moving web would have the same difficulty in that various constant, preset tensions and pressures are desired to insure proper control of the web. Various devices have been utilized in the past to accomplish control of webs and in most cases these devices have been large and cumbersome. Moreover, these devices do not operate automatically and it is necessary to have a skilled operator readily available for any alteration in conditions.

In the production of tubular members from paper webs there has also been a problem in accomplishing the proper tension on the web being wound about the mandrel to insure the proper application and sticking of the plies of material. Various devices that have been utilized for applying tension to control the amount of adhesive applied to the web have been expensive and cumbersome and of a complex construction not easily understood by the average operator of a spiral machine.

The above disadvantages are overcome by the instant invention wherein it is an object to provide a web tension control device which will reduce ply or web breakage and improve the bond between plies in a tubular construction. 7

It is another object to improve diameter control of tubular articles and ply gap control by utilization ofa novel web tension control device.

Still another object of the instnat invention is to provide a device for automatically tensioning a moving web of material to any desired, preset tension.

Another object of the instant invention is to provide an automatic web tension control device which is of simple and compact construction and easily operated.

A further object of the instant invention is to provide a device utilizing a tension producer with a tension sensor and connectingcontrols for coordinate operation of each. i

It is still another object of the instant invention to provide an automatic web tension control device utilizing a pneumatic system for sensing the tension on a web and applying a mechanical pressure to establish the desired tension in the web automatically.

Yet another object of the instant invention is to provide a tension sensor having a memberloaded in one direction by a load cell and in the opposite direction by the web to be tensed and utilizing pneumatic pressure escaping through a nozzle against a sensor arm to actuate the tension producer and automatically insure the proper tension on the web.

The above objects and advantages are accomplished by utilizing a pneumatic pressure sensor which operates on the web to determine the tension thereon and conveys a signal corresponding to the pressure escaping from the nozzle as caused by a rod sensor through controls which activate an air cylinder positioner for movement of a plurality of co-acting, oppositely disposed bars. The web is fed through these bars which exert a pressure on the web in relation to their angular displacement to one another.

Reference is now made to the drawings wherein like numerals refer to the same or similar parts and wherein the invention may be best understood by reference to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevational view, with portions omitted for clarity, of the device of the instant invention;

FIG. 2 is an enlarged side view of a portion of the device as shown in FIG. 1;

FIG. 3 is a side elevational view, with portions omitted for clarity, taken from the reverse side of the device of the instant invention from that shown in FIG. 1;

FIG. 4 is an end view of the device of the instant invention taken from the left of FIG. 1;

FIG. 5 is a schematic diagram of the pneumatic system and controls for; and instant invention.

FIG. 6 shows a partial view of a schematic diagram of an alternative embodiment of the system and controls shown in FIG. 5.

Referring now to the drawings and more particularly to FIG. 1 wherein the novel automatic web tension control apparatus 10 is shown to include sensor assembly 12 interconnected with actuator 16 by control system 14. Tension production assembly 18 accomplishes the actual tensioning of web 20.

The web tension control apparatus 10 may be mounted in the system for assembly of a spiral tube or in a position such that web 20 will run longitudinally therethrough. Tension control device 10 may be mounted from any foundation or support available and generally utilizes a mounting such as bracket 22 through which rods 24 extend to support the tension control device 10 from below. Side bars 26 are mounted and interconnected by guide 28 at one end and similar structure at the opposite end. Thus it is seen that a framework is established with side plates 26 forming the sides and which supports sub-assembly 12, control system 14, actuator 16 and tension producing assembly 18.

Tension producing assembly 18 is comprised of a plurality of operating arms 30 which are pivotally mounted over friction bars 32 extending between side plates 26 and which are connected to operating lever 34 by pivot 36. Movable friction bars 38 are mounted above and to the right, as seen in FIG. 1, of the fixed friction bars32. Because operating arms 30 are pivoted about fixed friction bars 32 and pivots 36 on operating lever 34, it is readily seen that a horizontal movement of lever 34 in the direction of travel of the web will effect an angular movement of movable friction bars 38 with regard to fixed friction bars 32. It is observed that web-20 passes over guide 28 and between each of the pairs of friction bars which is comprised of a fixed friction bar 32 and a movable friction bar 38. Thus as operating lever 34 moves to the right and causes movable friction bars 38 to move in an angularly downward direction a greater tension is applied to web 20 and less tension is applied as operating lever 34 moves to the left and rotates movable bars 38 upwardly and out of hard contact with web 20.

Lever 34 is connected to actuator 16 by pivot link 40 which pivots about a fixed friction bar 32 and cylinder rod 42 such that actuation of air cylinder 16 effects the horizontal movement of operating lever 34. Actuator 16 is of conventional construction having a diaphragm type cylinder for minimizing friction. This apparatus permits pressure exerted on one side of the diaphragm to effect movement of rod 42 and the attendant operating lever 34. Cylinder 16 is suspended from framework 44 which includes uprights 46 and cross bar 48. Cross bar 48 supports mounting rod 50 and spacer 52 upon which bracket 54' may pivot. Bracket 54 is rigidly attached to actuator 16 such that operation of cylinder 16 and an elongation of cylinder rod 42 will permit rotation of link 40 about fixed friction bar 32 and permit rotation of actuator 16 in order to cause movement of operating lever 34.

Actuator cylinder 16 has pneumatic fitting 56 interconnected with actuator pressure gauge 58.

Sensor assembly 12 is also mounted from side bars 26 and includes stationary bars 60 across which web 20 passes. Rod sensor pivot 62 extends across tension control device 10 and functions as a pivot for sensor arm 64. Sensor arm 64 has a pivot portion 66 which interconnects with rod sensor pivot 62 and sensor bar 68. Sensor portion 70 of sensor arm 64 extends forwardly and has pneumatic reflector plate 72 mounted on the lower edge 74 thereof for a purpose to be more fully understood hereinafter.

Sensor nozzle 80 is interconnected by pneumatic line 82 to relay 84 which forms part of control system 14.

Load cell 90 functions to provide a designated force against sensor arm 64 through rod 92 such that there is a given load on sensor bar 68 and a differential can be established. Load cell 90 is of conventional construction and is connected by pneumatic line 94 to pressure gauge 96 which is connected to regulator 122 that is capable, in one embodiment, of maintaining a pressure of to 30 psi. Load cell 90 is supported by support 98 and mount 100 which attach to side plates 26 and upright 46 of framework 44, respectively.

Reference may now be had to FIG. wherein a diagram of control system 14 is shown. It is seen that source of pneumatic pressure 110 provides the air passing through conduit 112 to filter 114 and through conduit 116 to regulator 118 for insuring a uniform pressure as required in each given instance. A pneumatic line 120 connects regulator 118 to regulator 122 which in turn is connected to load cell 90 and gauge 96 by conduit 124. Conduit 120 has a branch 126 which connects regulator 118 to pneumatic relay 84. It is noted that conduit 82 connects relay 84 with sensor nozzle 80. As seen in the schematic diagram of FIG. 5, a cross branch 128 connects conduit 82 with branch 126 through fixed orifice 140. However, it is to be understood, as seen in FIGS. 3 and 6, branch 128 with orifice 140 may connect

conduits

82 and 124, see especially FIG. 6.

Conduit 130' connects relay 84 to valve 132 which is connected by conduit 134 to gauge 58 and actuator cylinder 16. The direction of pneumatic flow can be observed by reference to the arrows in FIG. 5.

OPERATION The controller would be properly mounted through mounts 24 such that the longitudinal direction bars 32 and 38, respectively, being separated, as seen in FIG. 1, by the opening of toggle valve 132.

Web 20 of a material such as paper would be fed over guide 28 and between the respective pairs of fixed friction bars 32 and movable friction bars 38 to stationary bar 60. Web 20 then passes over sensor pivot 62 and under sensor bar 68. Web 20 extends beyond stationary bar 60 and to the point of use or the winding operation. Once the web has been fed through the controller 10 as noted, regulator 122 is gradually reset to permit greater sensor pressure on the air passing to load cell 90. As the pressure is increased through regulator 122 the pressure exerted by the load cell 90 on sensor arm 64 is increased. The pressure which escapes through nozzle will have an effect on the pressure of the air within conduit 82 and, therefore, the pressure within relay 84 which supplies and controls the air flowing to tension actuator 16.

The web tension is read by the movement of sensor bar 68 as web 20 passes between pivot 62 and sensor bar 68 thereby causing sensor arm 64 to be raised or lowered with the attendant reflector plate or flapper 72 such that there will be an alteration of pressure being released through nozzle 80. If the tension of the web is less than that required to balance the load cell force which is being exerted downwardly from load cell by rod 92 against sensor arm 64, the nozzle 80 is closed raising the back pressure in conduit 82 to effect a signal to relay 84. This increases the pressure to actuator cylinder 16 which acts on operating lever 34 to reset the movable friction bars 38 in reference to fixed friction bars 32 and thus applies greater pressure for greater tension until a balance is reached. The converse is also true and a greater tension causes reflector plate 72 and sensor arm 64 to raise permitting a greater flow of air from nozzle 80 and reducing the pressure in conduit 82 and relay 84. Thus, the air pressure to actuator cylinder 16 is reduced and pivot arm 42 would be raised such that operating lever 34 moves to the left, as seen in FIG. 1, effecting rotation of operating arms 30 counterclockwise. This action raises movable friction bars 38 upwardly to permit a less restrictive movement of web 20 between fixed friction bars 32 and movable friction bars 38.

Although the specific structure of cooperating tension bars is described, it is to be understood that tension in the web may be produced by a compression or other device which is powered by a fluid actuator.

Thus it is seen that the instant invention permits a variable designation of the tension of a moving web as desired by the machine operator. The operator can set the desired tension in the web and not have to maintain a continual surveillance of the operation as the web tension control device 10 senses the web tension and automatically adjusts the friction to insure a constant tension regardless of the angular positioning of the web. Because web tension can be controlled accurately there is substantial reduction of ply breakage and improved sticking of the various plies of the tube. The constant tension permits the scraper bars to have accurate contact with the web and thus leave a more uniform film of adhesive and improves the wander characteristic of the ply, as well as improving tube diameter control. The novel tension control apparatus of the invention is capable of use with various other equipment such as deckle grinders or skivers. The instant invention is economical in construction, requires minimal maintenance and there is no requirement for highly skilled personnel in the operation of the device. It is possible to rapidly rotate the friction bars and guides and guides and other parts as well as alter the angular positioning of the control device across the mounting bars 24 and thereby permit rapid alteration of the positioning of the device.

What is claimed is:

1. A web tension control apparatus comprising sensor means for determining the tension on a moving web; tension producing means for modifying the tension on the web; said sensor means including a member having a force applied in one direction by a load cell to counteract a force applied to said loaded member in the direction opposite to that of the load cell by the moving web; sensor arm means for actuating said tension producing means; nozzle means for directing pneumatic pressure against said sensor arm means to accomplish the actuation of the tension producing means; actuator means for activating said tension producing means; and control means interconnecting said actuator means and said sensor means, whereby the tension on the web is sensed and pressure is automatically applied to establish the desired tension in the web.

2. The web tension control apparatus of claim 1 wherein said tension producing means includes: a framework; at least one friction bar supported by said framework; an operating arm pivotally connected to each said friction bar; an operating lever pivotally attached to each of said operating arm; and at least one movable friction bar mounted on each said operating arm, whereby movement of said operating lever effects rotation of said operating arm and effects lesser or greater force against the web by said movable friction bar and said fixed friction bar.

3. The web tension control apparatus of claim 1 wherein said control means comprises: load cell means; at least one variable regulator in a first conduit for connecting a source of pneumatic pressure and said cell means; a pneumatic relay; a conduit connecting said relay to said first conduit; a second conduit connecting said relay to a valve and said valve to said actuator means; said cell means having a rod for operation with said sensor means; nozzle means for directing pneumatic pressure against said sensor means and connected with said relay by a third conduit; and a fourth conduit interconnecting said third conduit and said second conduit and having a fixed orifice therein. 1

4. A web tension control apparatus comprising sensor means for determining the tension on a moving web; tension producing means for modifying the tension on the web; said tension producing means including a framework; a plurality of friction bars supported by said framework; at least one operating arm pivotally connected to each said friction bar; an operating lever pivotally attached to each of said operating arms; movable friction bars mounted on said operating arms; actuator means for activating said tension producing means; and control means interconnecting said actuator means and said sensor means, whereby movement of said operating lever effects rotation of said operating arms and effects lesser or greater force against the web by said movable friction bars and said fixed friction bars.

5. A web tension control apparatus comprising sensor means for determining the tension on a moving web; said sensor means including a framework having at least one stationary bar across which the web may pass; sensor arm means pivotally mounted to said framework; said sensor arm having a sensor portion; a reflector plate mounted on said sensor portion; nozzle means for directing pneumatic pressure against said reflector plate; tension producing means for modifying the tension on the web; actuator means for activating said tension producing means; and control means interconnecting said actuator means in said sensor means, whereby the tension on the web is sensed and pressure is automatically applied to establish the desired tension in the web.

6. The web tension control apparatus of claim 5 wherein said control means comprises: load cell means; at least two variable regulators in a first conduit for connecting a source of pneumatic pressure and said cell means; a pneumatic relay; a conduit connecting said relay to said first conduit between said variable regulators; a second conduit connecting said relay to a valve and said valve to said actuator means; said cell means having a rod for operation with said sensor means; nozzle means for directing pneumatic pressure against said sensor means and connected with said relay by a third conduit; and a fourth conduit interconnecting said third conduit and said second conduit and having a fixed orifice therein.

7. The web tension control apparatus of claim 6 wherein said tension producing means includes: a framework; a plurality of friction bars supported by said framework; at least one operating arm pivotally connected to each said friction bar; an operating lever pivotally attached to each of said operating arms; and movable friction bars mounted on said operating arms. whereby movement of said operating lever effects rotation of said operating arms and effects lesser or greater force against the web by said movable friction bars and said fixed friction bars.

8. A web tension control apparatus comprising sensor means for determining the tension on a moving web; tension producing means for modifying the tension on the web; actuator means for activating said tension producing means; control means interconnecting said actuator meansand said sensor means; said control means including load cell means; at least one variable regulator in a first conduit for connecting a source of pneumatic pressure and said load cell means; a pneumatic relay; a conduit connecting said relay to said first conduit; a second conduit connecting said relay to a valve and said valve to said actuator means; said cell means having a rod for operation with said sensor means; nozzle means for directing pneumatic pressure against said sensor means and connected with said relay by a third conduit; and a fourth conduit interconnecting said third conduit and said second conduit and having a fixed orifice therein, whereby the tension on the web is sensed and pressure is automatically applied to establish the desired tension in the web.

9. The web tension control apparatus of claim 8 wherein said fourth conduit with said fixed orifice therein connects the third conduit connecting said nozzle means and said relay to said first conduit connecting 7 said variable regulator with said cell means.

UNITED sTATEs PATENT OFFICE ERTIFTCATE OF CORRECTION Patent No. 3,765,58 Dated: 7 October 16, 1973 E. Riley Rowe It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In the title information Assignee: Sonoco Products Company,

Hartsville, S. C.

Columnl, line 38 "'instnat"' should appear "instant- Signed and sealed this 21st day of May 197A.

v (SEAL) Attest: I c. MARSHALL DANN Commissioner of Patents EDX'IARD 1-i.FLETCl-H2I-i,JR. Attesting Officer

Claims

3. The web tension control apparatus of claim 1 wherein said control means comprises: load cell means; at least one variable regulator in a first conduit for connecting a source of pneumatic pressure and said cell means; a pneumatic relay; a conduit connecting said relay to said first conduit; a second conduit connecting said relay to a valve and said valve to said actuator means; said cell means having a rod for operation with said sensor means; nozzle means for directing pneumatic pressure against said sensor means and connected with said relay by a third conduit; and a fourth conduit interconnecting said third conduit and said second conduit and having a fixed orifice therein.

7. The web tension control apparatus of claim 6 wherein said tension producing means includes: a framework; a plurality of friction bars supported by said framework; at least one operating arm pivotally connected to each said friction bar; an operating lever pivotally attached to each of said operating arms; and movable friction bars mounted on said operating arms, whereby movement of said operating lever effects rotation of said operating arms and effects lesser or greater force against the web by said movable friction bars and said fixed frIction bars.

8. A web tension control apparatus comprising sensor means for determining the tension on a moving web; tension producing means for modifying the tension on the web; actuator means for activating said tension producing means; control means interconnecting said actuator means and said sensor means; said control means including load cell means; at least one variable regulator in a first conduit for connecting a source of pneumatic pressure and said load cell means; a pneumatic relay; a conduit connecting said relay to said first conduit; a second conduit connecting said relay to a valve and said valve to said actuator means; said cell means having a rod for operation with said sensor means; nozzle means for directing pneumatic pressure against said sensor means and connected with said relay by a third conduit; and a fourth conduit interconnecting said third conduit and said second conduit and having a fixed orifice therein, whereby the tension on the web is sensed and pressure is automatically applied to establish the desired tension in the web.

9. The web tension control apparatus of claim 8 wherein said fourth conduit with said fixed orifice therein connects the third conduit connecting said nozzle means and said relay to said first conduit connecting said variable regulator with said cell means.