GB2184263A - Spool type valve controller for a pneumatic guiding system - Google Patents

Abstract

The invention relates to a direct acting pneumatic control system for controlling a dual diaphragm, or double acting cylinder type automatic web guiding system. A control valve (15) is equipped with a palm or follower (18) which follows the web (10) and continually monitors the web position and activates a control valve spool (37) to modulate the "flow-exhaust" rates to bring the web (10) to a corrected position with no over-run or "hunting" for position. The palm (18) and its associated rod follow the web when the web is moving away from the palm by means of a helical spring (40), totally enclosed within the valve body (36), and acting directly on the valve spool (37). In the neutral position inlet 45 is connected to outlets 46 & 47 and exhaust 36d closed. <IMAGE>

Description

SPECIFICATION Spool type valve controller for a pneumatic guiding system The present invention relates to a control valveto continually monitorand control a guide roll position and effectively to cause this guide rol I to be moved in the necessary direction to maintain an endlessweb travelling in a straight run around a series of rolls.

The present invention presents a spool type pneumatic controller valve that operates within a 35 to 75 psi (2.41 to 5. 17 bar) input range and feedsthis output pressure directlyto a guide mechanism to accomplis necessary corrections. The controller valve of the present invention is unique in that itis not a pilot device but handlesfull flow directlytothe diaphragms and/or cylinder end withoutthe benefit of additional linkage, mechanism, or pneumatic boosters.

In accordance with a first aspect of the present invention, there is provided a spool type controller assemblyforcontrolling and directing airfrom an air sourceto a pneumatic guiding system that is operatively connected to a guide roll for moving and adjusting the guide roll so asto appropriately guide a web material overthe guide roll, said spool type controller comprising a valve having a body, a spool movably mounted therein, an air inlet port, outlet port means, and exhaust port means formed therein with said outlet port means being adapted to be communicatively connectible to said pneumatic guiding system, biasing means operatively associated with said spool for biasing the same toward a selected position or in a selected direction within the valve, spool actuating means for engaging an edge of said material passing oversaid guide roll and moving said spool back and forth within said valve in response to the lateral shifting of said materialasthesamepassesoversaidguideroli wherein the movement of said spool, as a result of the lateral movement of said material, results in the guiding system adjusting the position of said guide roll so asto adjustthe running angle ofthe material passing over said guide roll, said spool actuating means comprising pivot arm means coupled to said spool for moving said spool back and forth within said valve as said pivot arm means is moved back and forth, said pivot arm means including an inner end movably mounted to said spool and extending therefrom and further including a remote end having a follower secured thereto for engaging the edge of said material passing oversaid guide roll, such that said pivot arm means actuates and moves said spool back and forth within said valve in response to the lateral shifting ofthe material passing oversaid guide roll, said spool and pivot arm being adapted to assume a first neutral position and wherein from said neutral position said pivot arm may pivotto second and third extreme positions on opposite sides of said neutral position, and said valve and spool including means for opening said outlet port means and exposing the same to air pressurewhile closing said exhaust port means in responseto said spool and pivotarm assuming said neutral position, thereby preventing the valve from experiencing hunting.

In accordancewith a second aspectofthe present invention, there is provided a method of controlling a dual diaphragm fluid type control system that in turn controls the running angle of materials such as a web passing over a guide roll, said method comprising providing a spool type valve comprising two outlet ports and an exhaust port means and operatively interconnecting the same between said dual diaphragm fluid type control system and a source of fluid pressure, communicatively connecting a pair of outlet ports of said valvewith the dual diaphragms of thefluid control system, moving said spool back and forth through a neutral position and between two extreme positions within said valve to alternatively direct fluid to at leastone of the dual diaphragms of said fluid type control system for moving said guide roll back and forth and accordinglyvaryingthe running angle of material passing oversaid guide roll, opening saidtwo outlet ports and exposing the same to pressurized air and closing said exhaust port means in response to said spool assuming said neutral position, thereby preventing the spool type valve from hunting during the control process, said steps of moving said spools back and forth within said valve including engaging the edge of the material passing over said guide roll with a follower, moving a pivot arm back and forth in accordance with the movement of said follower, connecting said pivot arm with said spool and moving said spool back and forth in response to said pivot arm being moved back and forth so as to control the flow of said fluid from said valve to said respective diaphragms of said dual diaphragm control system for moving and adjusting the position of the guide roll and varying the running angle of material passing oversaid guide roll, and biasing said spool towards one of said extreme position by engaging the spool with a spring.

In accordance with a third aspect of the present invention there is provided a spool type controller assemblyforcontrolling and directing airfrom an air sourceto eitherside ofa dual diaphragm pneumatic guiding system that is operatively connected to a guide roll for moving and adjusting the guide roll so as to appropriately guide a web material overthe guide roll, said spool type controller comprising a valve having a body, a spool movably mounted therein, an air inlet port, a pair of outlet ports, exhaust port meansformed therein with each outlet port being adapted to be communicatively connectibleto a respective diaphragm of said pneumatic guiding system, biasing means operatively associated with said spool for biasing the sametoward a selected position or in a selected direction within said valve, spool actuating means for engaging an edge of said material passing over said guide roll and moving said spool back and forth within said valve in response to the lateral shifting of said material as the same passes oversaid guide roll wherein the movement of said spool, as a resultof the lateral movement of said material, results in the guiding system adjusting the position of said guide roll so asto adjustthe running angle of the material passing oversaid guide roll, said spool actuating means comprising pivot arm means coupled to said spool for moving said spool back and forth within said valve as said pivot arm means is moved back and forth, said pivot arm means including an inner end movably mounted to said spool and extending therefrom and further including a remote end having afollowersecuredthereto forengaging the edge of said material passing oversaid guide roll, such that said pivot arm means actuates and moves said spool back and forth within said valve in response to the lateral shifting of the material passing oversaid guide roll, a movable member movably mounted within a cavity associated with said spool with said movable member being movable back and forth within said cavity and valve in a direction normal to the direction of movement of said spool, and wherein a pivot arm is pivotably mounted within said movable member and connected to the inner end of said pivot arm such that as said pivot arm moves back and forth said pivot arm pivots within said movable membercausing said spool to be shifted back and forth while said movable member moves transverselytothe normal direction of said spool, said spool and pivot arm being adapted to assume a first neutral position and wherein from said neutral position said pivot arm may pivotto second and third extreme positions on opposite sides of said neutral position, and said valve and spool comprising meansforopening said outlet ports and exposing the sameto air pressure while closing said exhaustport means in responseto said spool and pivotarm assuming said neutral position, thereby preventing thevalvefrom experiencing"hunting".

The control valve of the present invention is designed to control a guide roll very precisely and this is accomplished through the particular design of porting within the valve. The"dead zone"area of "no correction"atthe neutral position ofthefollower (or palm) is approximately one-eighth inch (0.3175 cm). This porting design and arrangementwas designed and developed to give fast and accurate response even atthe low range of inlet pressure operation of 30-35 psi (2. 07-2.41 bar), and to maintain any correction to the guide roll position until an additional correction is called for as a result of a change in the position of the web or material being guided and controlled. This unique design feature of the valve controller eliminatesthe "hunting"characteristic usually associated with such guide valves. This design feature within the controllervalve is possible becauseofthe relatively small movement of the spool within the valve body compared to web movement. The presentspool design and the large ratio of palm movementto spool movement makes the valve sensitive and responsiveto small changes in web position.

An advantage ofthe present invention isthat it provides a spool valve for a fluidic guiding system of thetypethatcontrolstherunningangleofmaterial passing overa guide roll thatovercomes manyofthe disadvantages and drawbacks of conventional control systems.

Afurtheradvantage of the present invention is the provision of a control valvefor a fluidic guiding system of the character referred to above which is simple in construction, includes relativelyfew moving parts, is reliable, and which requires little or no maintenance.

The present invention also provides a spool type control valve for a web guide roll guiding system that accurately and precisely responds to the movement ofthe web or other material passing overthe guide roll.

Another advantage of the present invention resides in the provision of a spool type control valve for such a guiding systemwhich includesa pivotarm directly operating the sliding spool which is responsiveto lateral movement of material passing overthe guide roll for actuating the spool accordingly so as to vary and control the running angle of the material passing overthe same guide roll.

Afurther advantage of the present invention resides in the provision of a spool type control valve for a guiding system that is relatively inexpensive, butwhich is rugged in construction.

Afurther advantage of the present invention is that it provides a spool type control valve for controlling a web guiding system of the character referredto above which requires no adjustments and whose operation is not subjectto temperature changes.

Still a further advantage ofthe present invention resides in the provision of a spool type control valve for a web guiding system of the character referred to above which is applicable and can be used with all web guiding applications.

Afurther advantage of the present invention resides in the provision of a spool type control valve for a web guiding system that requires no air supply treatment dueto the relatively large orifices utilized.

Another advantage of the present invention resides in the provision of a web guiding system control valvewhich includes a universal mounting that enables the same to be mounted either right-handed or left-handed and which can be conveniently located remotely from the guiding system.

Another advantage of the present invention resides in the provision of a web guiding system spool type control valvethatcan be used on single diaphragm spring return type guiding systems by simply plugging one outlet port.

Still a further advantage of the present invention resides in the provision of a web guiding control valvethat includes a following arm and palm that is biased to monitor continuously an edge of material passing over a guide roll wherein the pressure exerted againstthe guide arm, in orderto maintain the same in a contact relationship, is of a relatively low pressure.

Another advantage of the present invention resides in the provision of a spool type control valve for a web guiding system that is completely enclosed so as to prevent contamination.

It is another advantage of the present invention in that it provides a web guiding system control valve that is very compact.

It is also an advantage of the present invention in that it provides a spool type control valve ofthe character referred to above wherein the spool thereof is biased towards one extreme position by an enclosed helical spring.

Other objects and advantages of the present invention will become apparentfrom a study of the following description and the accompanying drawings which are merely illustrative of such invention.

By way of example only, a specific embodiment of the present invention will now be described, with reference to the accompanying drawings, in which: Figure 1 is a side view of an endless web passing around a series of rollers including a guide roller ; Figures 2a, 2b and 2c are top plan views of three separate web arrangements similarto that shown in Figure 1, wherein in each ofthethreecasestheguide roller is shown in a particular position to illustratethe natural direction that the web tends to follow as a result of the particular positioning of one end of the guide roller ; Figure 3 is a schematic illustration of the guide roll system, control valve, and associated plumbing for directing airto and through the control valve and into the guide roll control system; Figure4isasectionalviewillustratingthespool type controller of the present invention with the spool being shown in neutral position; Figure5is an enlarged sectional viewshowing a selected portion of the valve and its spool with the spool being in the neutral position ; Figure 6is a schematic illustration ofthe control valve of the present invention illustrating the flow of airtherethrough when the pal m of the control valve as shown in Figure 4 assumes the left-most extreme position (position No. 2) ; Figure 7 is a schematic illustration of the control valve of the present invention illustrating the flow of airtherethrough when the palm of the control valve asshown in Figure4assumestheneutral position (position No. 1); Figure 8 is a schematic illustration of the control valve of the present invention illustrating the flow of airtherethrough when the palm of the control valve asshown in Figure4assumestheright-most extreme position (position No. 3); and Figure 9 is a graph illustration showing pressure measurementsforvariouspalm movementsofthe control valve of the present invention.

With further reference to the drawings, reference is madeto Figures 1,2a, 2b and 2c in orderto illustrate the manner of maintaining proper running alignment of an endless web. In Figure 1 an endless web 10 is shown passing around a series of carrier rolls 12. A guide roll, indicated bythe numeral 16, is provided, andasseeninFigure1, web10travels thereover. In addition a palm or guide arm 18 is illustrated in Figure 1. The palm orfollower 18, aswill be understoodfrom subsequent portions of this disclosure, is utilized in conjunction with a control system that is responsive to lateral orside-to-side movement of the web 10 for appropriately correcting and controlling the running alignment of the web 10.

In Figure 2a, the position of guide roll 16 results in theweb 10 moving inthedirection ofthearrow shown therein. Moving one end of guide roll 16to the position shown in Figure 2b causestheweb 10to move generally in the direction ofthe arrowshown therein. Bymovingguideroll 16totheposition shown in Figure 2c results in the web 10 moving in the direction of the arrow as shown therein.

Therefore, in the case of an endless web 10, it is desirable to sense continuallythe position of the edge of the web with a palm orfollower 18 (as illustrated in Figure 1) and in responsetothat position to adjust by moving the ends of guide roll 16 so asto control and correctthe alignment of the web 10 appropriately.

Nowturning to Figure 3, an actuator or guide system for moving guide roll 16 back and forth is shown therein and indicated generally bythe numeral 20. Actuator 20 is of a conventional design, and includes a saddle bearing holder 22that is designed to receive an end bearing assembly of guide roll 16. Disposed on each side of saddle bearing holder 22 is a pairof diaphragms 24 and 26. It is appreciated that by inflating and deflating the respective diaphragms 24 and 26, saddle bearing holder 22, and accordingly guide roll 16, can be moved back and forth. It is this back-and-forth control movementthat results in the continuous control ofthe alignmentofweb 10.

The present invention particularly relatesto a control valve, indicated generally bythe numeral 15, for controlling actuator 20 and the respective diaphragms 24and 26thereof. Details of the control valve will be specifically dealtwith subsequently herein. Priorto looking and viewing atthe details of controllervalve 15, a general discussion of the air flowtothe control valve andto and from the actuator 20 will be dealtwith.

In this regard, reference is madeto Figure3.

Therein an airsupply indicated bythe numeral 28 is provided. Airfrom the air supply 28 is directed through an inlet line 13to a particular inlet port ofthe control valve 15. Air passing through line 13 will pass through an on-offvalve30, filter32and a pressure regulator34.

Control valve 15 is mounted adjacentthetraveling web 10 by a universal support structure 21. As will be discussed in more detail subsequently herein, control valve 15 includes a palm orfollower 18that continuously monitors the edge of web 10 and responds to the lateral movementthereof so as continuouslyto varythe outputflowfrom control valve 15. Note in Figure3thatcontrol valve 15further includes two additional ports that again will be discussed in more detail subsequently herein. These two ports are operatively connected to diaphragms 24 and 26 via lines 17 and 19.

Turning to Figure 4, there is shown therein a spool type valve controller, indicated generally by the numeral 15. Control valve 15 comprises a housing structure 36 which includes a sliding spool 37. Valve 15further includes a pair of end covers 36a and 36b.

End covers 36a and 36b aresecuredtovalve body36 forming a closed chamberwithin which spool 37 operates and wherein spool 37 is designed to move laterally back and forth therein in a shifting fashion.

Disposed within one end of thevalve body, within a cavityformed, is a helical spring 40 that bears against one end of the spool 37 and is engaged about an opposite end by end cover36b. Sufficientspring thrust is available to bias spool 37 towards the leftas viewed in Figure 4 causing palm 18 to followthe web 10.

Continuing to referto Figure 4, a rod 38 extends from pivot arm 42 which is pivotablymounted to valve body36through a pivot pin 41. Pivot arm 42 extends inwardly into the valve 36 and is connected to ball cap 43 that is confined within the spool 37. Ball cap 43 is capable of transverse movementwithin the valve 15 as pivot arm 42 is swung back and forth about pivot pin 41. In particular, ball cap 43 can slide or move up and down as viewed in Figure 4 in a transverse direction to the longitudinal axis of spool 37. Thus it is appreciated thatthe movement of rod 38 allowsthe rotary motion of pivot arm 42 to be converted to sliding motion between ball cap 43 and spool 37. Secured to valve 36 and extending therefrom around pivot arm 42 is a bellows 44thatis providedto protectthe interiorofthevalve 15from exterior contaminants.

Formed in valve housing 36 is an inlet air port45, two outlet ports 46 and 47, and two exhaust ports 36c and 36d. Vent holes 36e and 36fventthevalve housing to prevent any pressure build-up from spool movement as well as that occurring from leakage pastspool 37.

In orderto direct inletairfrom inlet air port45to various areas ofthe valve 15, spool 37 is selectively drille. In this regard, there are provided ports 37b and 37cwhich are drilled from the exterior of spool 37 to a central longitudinal port 37a. In addition, as shown in Figure4, therearetwoadditional ports, 37d and 37e, that are formed in spool 37 and which extend from 37a outwardly therefrom to and through thesideofspool 37. Central port37a isterminated aboutthe left end of spool 37 by a plug 37f.

Also as shown in Figure 4, it is seen thatspool 37 includes a series of selected raised shoulders that are utilized to control and directtheflow of airthrough the valve when spool 37 is disposed in various positions within the valve. Attention is directed to raised shoulders 31 and 33 thatgenerally control the flow of airto outlet ports 46 and 47. Notethat each of the raised shoulders 31 and 33 includes a notched area referred to as 31 a in Figure 5. These notched areas allowfor continuous pressure to be exposed to ports 46 and 47 when the valve 15 assumes a neutral position. This will effectively exert a constant pressure against both diaphragms 24 and 26 of the actuator20. Aswill be eluded to subsequently herein, this eliminates the undesirable characteristic known as"hunting".

With further reference to Figure 4, it is seen that a palm 18 is secured to rod 38, and in an operative mode, palm 18 engages the side of web 10. Control valve 15 and palm 18 as shown in Figure 4 are disposed in thefirstor neutral position. In this neutral position, inlet port45 is open to spool ports 37a, 37b, 37c, 37d and 37e. Also in this first or neutral position, both outlet ports 46 and 47 are slightlyopen to inlet pressure, again as illustrated in Figure 5. This effectively holdsthe guide in a neutral position until an addition correction is called forbythe movement of palm 18. Exhaust ports 36c and 36d are closed.

In Figure 4, there are shown two construction lines 60 and 62. Construction line 60 represents the position of palm 18 and rod 38 when it assumes what is referredto. as"palm position No. 2". Construction line 62 represents what is referred to as"palm position No. 3".

In palm position No. 2, it is seen thatthe rod and palm will move from the neutral position a maximum of twenty degrees. In position No. 2, in ! et port 45 is open to outlet port46through port37b, 37a and 37d. Exhaust port 36c is blocked. In position No.

2, port 47 is effectively open to exhaust 36d.

Consequently, airflowfrom a respective diaphragm of actuator 20 can be exhausted from exhaust 36d via port 47.

In palm position No. 3, illustrated by construction line 62, here again rod 38 and palm 18 assume position of approximately 20 degrees maximum from the neutral position. In position No. 3, inlet port 45 is open to port47 through ports 37c, 37a and 37e.

Exhaust port 36d is blocked. Port 46 is open to exhaust port36c. Therefore, airfrom a respective diaphragm of actuator 20 that is connected to port46 can be exhausted to exhaust port36c.

In Figures 6, 7 and 8, the flow of airthrough valve 15 is illustrated in each of the three positionsjust described. In Figure 6, palm position No. 2 (construction line 60) is illustrated. In Figure7, the neutral position is illustrated Figure 8 illustrates the third palm position orthe position occupied bythe palm 18whenthesameassumesthatposition represented by construction line 62 in Figure 4.

It is appreciated that as palm 18 moves slightly from the neutral position towards palm position No.

2that outlet port46 becomes increasingly exposed to inlet pressure and outlet port 47 becomes increasingly exposed to exhaust port36d. For minor corrections to the web 10 position, the flow rates are low and the corresponding speed of correction is slow. This eliminates over-reaction and consequently"hunting"ofthe guide roll 12.

Essentiallytheflowto the respective diaphragms 24 or 26 or to a cylinder end is proportional to the displacementof palm 18toward either palm position No. 2 or No. 3 relative to the neutral position.

The opposite conditions exist and prevail when pal m 18 moves from the neutral position towards palm position No. 3. That is, outlet port 47 becomes increasingly open to inlet pressure and outlet port46 becomes increasingly exposed to exhaust port36c.

Again the flows are proportional to spool displacement. it is appreciated that helical spring 40 in bearing against spool 37 supplies sufficientforce and pressureto assure that palm 18 continuouslyfollows an adjacent edge of web 10 Figure 9 displays a graph of actual diaphragm pressures plotted from the zero or neutral position of the actuator orguide roll carrier. These pressures are given foreach 0.25" (0.635 cm) of palm movement, and illustratethe gradual and relatively straight line increase in pressure on the high pressure side and the corresponding decrease in pressure on the exhaust or low pressure side.

The gradual increase in force on the high pressure side results in a very uniform speed of movement, and provides precise control of the guide roll through the entire range of movement.

Reversal of high pressure and low pressure sides would result in a mirrorimage ofthe graph.

Claims (13)

The present invention may, of course, be carried out in other specific ways than those herein set fort without departing from the spirit and essential characteristics of the invention. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended Claims are intended to be embraced therein. CLAIMS

1. A spool type controller assembly for controlling and directing air from an air source to a pneumatic guiding system that is operatively connected to a guide roll for moving and adjusting the guide roll so as to appropriately guide a web material overthe guide roll, said spool type controller comprising a valve having a body, a spool movably mounted therein, an air inlet port, outlet port means, and exhaust port means formed therein with said outlet port means being adapted to be communicatively connectible to said pneumatic guiding system, biasing means operatively associated with said spool for biasing the same toward a selected position or in a selected direction within said valve, spool actuating means for engaging an edge of said material passing oversaid guide roll and moving said spool back andforth within said valve in response to the lateral shifting of said material as the same passes oversaid guide roll wherein the movement of said spool, as a result of the lateral movement of said material, results in the guiding system adjusting the position of said guide roll so asto adjustthe running angle ofthe material passing oversaid guide roll, said spool actuating means comprising pivot arm means coupled to said spool for moving said spool back and forth within said valve as said pivot arm means is moved back and forth, said pivot arm means including an inner end movably mounted to said spool and extending therefrom and further including a remote end having a follower secured thereto for engaging the edge of said material passing oversaid guide roll, such that said pivot arm means actuates and moves said spool back and forth within said valve in response to the lateral shifting ofthe material passing oversaid guide roll, said spool and pivot arm being adapted to assume a first neutral position and wherein from said neutral position said pivotarm maypivotto second and third extreme positions on opposite sides of said neutral position, and said valve and spool including means for opening said outlet port means and exposing the same to air pressure while closing said exhaust port means in response to said spool and pivot arm assuming said neutral position, thereby preventing the valve from experiencing hunting.

2. Aspooltypecontrollerasclaimedinclaim1, wherein the biasing means comprises a helical spring disposed within said valve body and disposed adjacent said spool so as to engage said spool and to biasthe same in a selected direction.

3. A spool type controller as claimed in claim 1 or claim 2, including a joint assembly operatively interconnected between said spool and said pivot arm means.

4. A spool type controller as claimed in claim 3, wherein said joint assembly includes a cavityformed in said spool and an opening providing access thereto, and a movable member contained within said cavity and operatively connected to said pivot arm means such that as said pivot arm is moved back and forth said spool is moved back and forth with said valve via said joint assembly converting rotary to sliding motion.

5. A spool type controller as claimed in claim 4, wherein said joint assembly is movabletransversely in a direction substantially normal tothe longitudinal axis of said spool as said pivot arm means is moved back and forth.

6. A spool type controller as claimed in claim 5, further comprising a pivot pin connecting said pivot arm means with said valve adjacent said joint assembly.

7. A spool type controller as claimed in claim 6, comprising a pivot arm opening formed in said valve through which said pivot arm means projects, and wherein there is provided a flexible boot secured to said valve adjacent said pivot arm opening and which encompasses a portion of said pivot arm extending from said valve.

8. A method of controlling a dual diaphragm fluid type control system that in turn controls the running angle of materials such as a web passing over a guide roll, said method comprising providing a spool type valve comprising two outlet ports and an exhaust port means and operatively interconnecting the same between said dual diaphragm fluid type control system and a source of fluid pressure, communicatively connecting a pairof outlet ports of said valvewith the dual diaphragms of thefluid control system, moving said spool back and forth through a neutral position and between two extreme positions within said valve to alternatively direct fluid to at leastone ofthe dual diaphragms ofsaid fluid type control system for moving said guide roll backandforth and accordinglyvarying the running angle of material passing over said guide roll, opening said two outlet ports and exposing the same to pressurized air and closing said exhaust port means in responseto said spool assuming said neutral position, thereby preventing the spool type valvefrom hunting during the control process, said steps of moving said spools back and forth within said valve including engaging the edge of the material passing over said guide roll with a follower, moving a pivot arm back and forth in accordance with the movement of said follower, connecting said pivot arm with said spool and moving said spool back and forth in response to said pivot arm being moved back and forth so asto control the f low of said fluid from said valve to said respective diaphragms of said dual diaphragm control system for moving and adjusting the position of the guide roll and varying the running angle of material passing over said guide roll, and biasing said spool towards one of said extreme position by engaging the spool with a spring.

9. A method of controlling a dual diaphragm fluid type control system as claimed in claim 8, wherein the step of connecting said pivot arm to said spool includes interposing a movable member between said spool and said pivot arm and moving said movable member in a direction substantially noraml tothe movement of said spool as said pivot arm is moved back and forth.

10. A spool type controller assemblyfor controlling and directing airfrom an airsourceto eithersideofa dual diaphragm pneumatic guiding systemthatis operatively connected to a guide roll for moving and adjusting the guide roll so asto appropriately guide a web material overthe guide roll, said spool type controller comprising a valve having a body, a spool movably mounted therein, an air inlet port, a pair of outlet ports, exhaust port meansformed therein with each outlet port being adapted to be communicatively connectible to a respective diaphragm of said pneumatic guiding system, biasing means operatively associated with said spool for biasing the same toward a selected position or in a selected direction within said valve, spool actuating meansforengaging an edge of said material passing over said guide roll and moving said spool back and forth within said valve in responseto the lateral shifting of said material asthe same passes over said guide roll wherein the movement of said spool, as a result of the lateral movementofsaid materiai, results intheguiding system adjusting the position of said guide roll so as to adjustthe running angle of the material passing oversaid guide roll, said spool actuating means comprising pivot arm means coupled to said spool for moving said spool backand forth within said valve as said pivot arm means is moved baclcand forth, said pivot arm means including an inner end movably mounted to said spool and extending therefrom and further including a remote end having afollowersecuredthereto for engaging the edgeof said material passing over said guide roll, such that said pivotarm means actuates and moves said spool back and forth within said valve in response to the lateral shifting ofthe material passing oversaid guide roll, a movable member movably mounted within a cavity associated with said spool with said movable member being movable back and forth within said cavity and valve in a direction normal to the direction of movement of said spool, and wherein a pivotarm is pivotably mounted within said movable member and connected to the inner end of said pivot arm such that as said pivot arm moves back and forth said pivotarm pivots within said movable member causing said spool to be shifted back and forth while said movable member moves transverselytothe normal direction of said spool, said spool and pivotarm being adapted to assume a first neutral position and wherein from said neutral position said pivot arm may pivot to second and third extreme positions on opposite sides of said neutral position, and said valve and spool comprising meansfor opening said outlet ports and exposing the same to air pressure while closing said exhaust port means in responseto said spool and pivot arm assuming said neutral position, thereby preventing thevalvefrom experiencing"hunting".

11. A spool type controller assembly for controlling and directing airfrom an airsourceto a pneumatic guiding system, substantially as herein described, with reference to, and as illustrated in, the accompanying drawings.

12. A method of controlling a dual diaphragm fluid type control system, substantially as herein described, with referenceto, and as illustrated in, the accompanying drawings.

13. A spoo I type controller assembly for controlling and directing airfrom an airsourceto eitherside of a dual diaphragm pneumaticguiding system, substantially as herein described, with reference to and as illustrated in, the accompanying drawings.