US3542645A - Web machine adjustment mechanism and indicator recording means therefor - Google Patents

Description

NOV. 24, 1970 MEHLMAN ETAL 3,542,645 WEB MACHINE ADJUSTMENT MECHANISM AND IND ICATOR v RECORDING MEANS THEREFOR Filed June 30, .1967 4 4 Sheets-Sheet 1 'llllH .A'iiiiiiiiidiii'!!! INVENTORS ATTORNEYS ames?- "sm: f w I Filed dt me 30.1967 1 Nov. 24,1970 v H. B. MEHLMAN ETAL 3,542,645

WEB MACHINE ADJUSTMENT MECHANISM AND INDICATOR RECORDING MEANS THEREFOR 4 Sheets-She et 2 INVENTORS HOWARD B. MEHLMAN JAMES H. THOMPS N avg M 4" @Xfidw A TORNEYS FIG. 3

Nov. 24, 1970 H. B. MEHLMAN ETAL 3,542,645

WEB MACHINE ADJUSTMENT MECHANISM AND INDICATOR RECORDING MEANS THEREFOR 4' Sheets-Sheet 5 Filed Jun 30, 19 67 wNoz ll wF l b :EJ E5 ES H. THOMP ON I R NEYS INVENTORS HOWARD B.MEHLMAN JA w m ...O.. wdz 58 13% 5.5 oz J v oz wulfilzmw I SE28 d8 10:26 mv 538mm H. B.-MEHLMAN ETAL .WEB MACHINE ADJUSTMENT MECHANISM AND INDICATOR 4 Sheets-Sheet 4 nmconnme MEANS THEREFOR 7 Nov. 24, 197

Filed Jun sq; i967 FIG, 5 v

LEFT LIMIT CONTACT 1 2;

MICRO-SWITCH Q0 T gr 2 ROTARY M STEPPING i I SWITCH f I I MIC o-swncn CONTACT 24 g LEFT um'ri qh-I v v DEMAND w p ARM LEFT LIMIT I .A MICRO-SWITCH .CONTACT 2a 46 l P; i 2 I I I mcao-swncn CONTACT 50 I 2 LEFT LIMIT DEM)ND CONTA T 52 INVENTORS HOWARD B. MEHLMAN JAMES H.THOMP$ON United States Patent Olfice WEB MACHINE ADJUSTMENT MECHANISM AND INDICATOR RECORDING MEANS THEREFOR Howard B. Mehlman and James H. Thompson, Millinocket, Maine, assignors to Great Northern Nekoosa Corporation, a corporation of Maine Filed June 30, 1967, Ser. No. 650,466 Int. Cl. D21f 7/06 US. Cl. 162-259 4 Claims ABSTRACT OF THE DISCLOSURE A web producing machine adjustment mechanism having a plurality of adjustment screws with two actuators for each screw to rotate the screw in opposite directions where each actuator has a ratchet wheel on the screw and a solenoid operated pawl for engaging and rotating the ratchet wheel and screw. Recording means for indicating the relative rotational position of each of a plurality of adjustment screws on a chart where the same recording means can also record characteristics of the web being produced.

BACKGROUND OF THE INVENTION The invention relates to a means for positively and accurately adjusting a plurality of screw-operated adjusting mechanisms extending across the width of a machine through which a web passes and further relates to a recording means wherein the position of each of the adjusting mechanisms may be recorded on a single recorder and wherein the same recorder may be used to record other web characteristics.

In paper making machines, for example, it is often desirable to vary the amount of pulp dispensed from a pulp headbox onto the moving wire of a Fourdrinier type ma chine in order to maintain the weight of the paper Within acceptable limits. This is conventionally done by having a movable slice lip which regulates the size of an opening in the head box through which the pulp is dispensed onto the wire. It is often desirable that the lip be adjustable along its length to vary and regulate the amount of pulp distributed to the wire over the width of the wire to assure constant weight over the width of the web of paper being produced. In the past, this has been done by having a plurality of adjustment screws which extend across the lip such that rotation of the screws will bend portions of the lip to vary the opening across the head box. The placement of the screws, however, make accurate adjustment of the screws difiicult since the screws are not readily accessible for manual adjustment. Further, if conventional remote controlled actuators are used to turn the screws, accurate adjustment is difficult to obtain since the degree of turning of the screw is often dependent on the length of time that the actuator is activated or on degree of movement of the actuator which may vary with each act of adjustment.

It is necessary that. any adjustment of the slice lip be made quickly to reduce excess waste since, particularly in modern paper making machines, paper is produced at a fast rate. Variation in cross-machine profiles of basis weight are detrimental because the resulting paper web does not handle well in the latter stages of papermaking such as winding into rolls nor does it perform well in printing presses.

It is further desirable in paper making machines that any devices for the regulation of the slice lip be capable of being operated by a computer which may compare the weight profile of the paper being produced with the desired weight profile and, once the comparison has been 3,542,645 Patented Nov. 24, 1970 made, automatically adjust the slice lip to achieve the desired weight profile.

It is therefore an object of our invention to provide for an actuator mechanism for use with screw type adjustment means which may be remotely controlled and which will insure accurate and precise rotation of the adjustment screw. It is also an object of the invention to provide for a recorder device which will indicate the position of a plurality of adjustment means and also provide convenient comparison of the position of the adjustment means with a characteristic of the goods produced on a machine, for example, comparison of the profile of slice lip with the profile of the basis weight of paper being produced on a paper machine.

Broadly, our invention comprises utilizing two actuators for each screw adjusting mechanism of a machine through which a web passes where rotation of the screw will vary the characteristics of the web passing through the machine. Each screw has thereon two toothed ratchet wheels which are adapted to be engaged by a pawl connected to an electrical solenoid wherein one solenoid operates to turn the screw in one direction and the other solenoid operates to turn the screw in an opposite direction. The use of the pawl and ratchet in conjunction with the solenoid assures that the screw will rotate a predetermined amount upon each separate actuation of the solenoid so that it is not a design condition that the electrical pulse operating the solenoid last for any particular length of time.

Our invention also includes having a recorder which will indicate on a chart the relative position of each screw of an adjustment means. The recorder comprises broadly an indicator pen movable along the X and Y axes of a chart where a drive shaft is connected to move the pen along the X axis. A micro switch is adapted to be actuated by rotation of the X axis drive shaft to in turn actuate a rotatable stepping switch. A potentiometer is associated with each screw and is connected to contacts associated with one step of the stepping switch. The common side of the stepping switch is connected to electrical means for moving the Y axis of the indicator pen. As the stepping switch rotates, it connects by means of wiper arms the potentiometer of each screw with the electrical means moving the indicator arm so that the relative position of each screw means may be recorded by a single indicator pen on a chart.

In addition, the invention includes the concept of having the indicator means used to record other characteristics when not recording the position of the screws, as for example, the basis Weight of paper produced on a machine such that a convenient comparison may be made on the recorder chart between the position of the adjustment screws and basis weight of the web of paper being produced.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic cross-sectional view of a part of a paper machine including the pulp head box and slice;

FIG. 2 is an enlarged side view of a portion of FIG. 1 illustrating the actuating means for turning an adjustment screw to adjust the slice;

FIG. 3 is a plan view of FIG. 2;

FIG. 4 is a diagram of a portion of the electrical circuit connecting a recorder with the adjustment screws to indicate the position of the adjustment screws;

FIG. 5 is a diagram of a portion of the circuit illustrating sequence of operation of the recording device; and

FIG. 6 is an illustration of a typical recorder read-out chart indicating the position of adjustment screws and other characteristics of a web.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, there is illustrated a head box 1 of a paper machine for holding pulp which is dispensed through a slice opening 2 onto a moving endless wire 3 which passes over a breast roll 4. The slice Opening 2 which extends across the width of the machine is formed by a bottom slice lip 5 and an upper slice lip 6. The upper slice lip 6 is flexible and can be moved up and down in a plurality of localized areas or portions to adjustably vary the size of the opening 2 across the Width of the paper machine and thus vary the amount of pulp dispensed from the head box in any given period of time. A plurality of hollow shafts 7 are connected to the lip 6 along its length such that each shaft is connected to and may raise or lower a portion of the lip. For convenience, only one shaft 7 and its associated parts are described.

Each shaft 7 is internally threaded and engages with a screw 8 which passes through the frame 9 of the head box. Screw 8 in turn is rotated by means of two actuators 10 and 11 mounted on the head box frame whereby rotation of the screw 8 in one direction will raise the lip portion to which the shaft 7 is attached while rotation in the opposite direction will lower the lip portion.

Referring to FIGS. 2 and 3, the actuators 10 and 11 are illustrated in greater detail. Actuators 10 and 11 are identical with the exception that a portion of one is a mirror image of a portion of the other as more fully explained hereafter. For convenience, only actuator 11 will be described in detail.

Actuator 11 is mounted on a plate 12 which in turn may be mounted to any portion of the paper machine in which it is desired to rotate a screw adjustment mechanism. The actuator comprises a toothed ratchet wheel 13 which is mounted on shaft 8 so as to rotate with the shaft. A pawl 14 is adapted to engage with individual teeth 15 of the ratchet wheel to drive the wheel in a counterclockwise direction as shown in FIG. 3. Pawl 14 in turn is pivotably mounted on a first link 16, and is urged in a direction to contact the teeth of the ratchet wheel by means of a pawl spring 17. A screw-adjusted stop 18 carried by bracket 18' in turn mounted on plate 12 bears against the pawl when the actuator is not acti vated to assure that the pawl will be clear of the teeth of the ratchet wheel.

Link 16 is pivotably mounted with respect to shaft 8 such that as link 16 pivots counterclockwise about the shaft, pawl 14 will be urged into driving engagement with a tooth by spring 17. The other end of link 16 is pivotably connected to a second link 19 by means of a bolt 20. Link 19 in turn is connected to link 19 to form a toggle joint which may articulate around bolt 23. Link 19' is pivotably supported by plate 12 through bolt 21.

A solenoid armature 22 is pivotably connected to the center of the toggle joint by bolt 23. Solenoid armature 22 in turn is slidable in the solenoid 24 which is connected to the plate 12 by bolt 25. Bolt 25 is eccentrically mounted with respect to flange 26 of the solenoid in order that the solenoid may be accurately positioned and so that the stroke of the armature may be adjusted.

A stop screw 27 carried by bracket 27' serves to limit movement of the toggle joint in the return direction as shown in FIG. 3 and acts as an outer stop for the armature 22. A spring 28 is connected at one end to a pin 29 mounted on the plate 12 and at its other end to a link 30 in turn connected to link 19. Spring 28 serves as a reset for the system and returns the parts to the positions shown in FIG. 3, when the solenoid is de-energized.

It is seen that when the solenoid 24 is energized, the armature 22 will move to the left, thus flexing the toggle joint which causes bolt 20 to approach bolt 21 which in turn causes link 16 to rotate in a counterclockwise direction. This movement in turn will cause the pawl 14 to engage a tooth of the ratchet wheel and rotate the ratchet wheel and screw 8 in the counterclockwise direction one tooth length. When the solenoid 24 is de-energized, spring 28 will pull the armature to the right thus causing link 16 to move in a clockwise direction and allow pawl 14 to ride over the rise of a tooth against the forces of spring 17 until link 19 hits on stop 27.

The construction of the actuator 10 is the same as that of actuator 11 with the exception that all of the parts with the exception of the solenoid and armature are reversed as well as the teeth on the ratchet Wheel so that actuation of the solenoid will cause the ratchet wheel and screw 8 to rotate in a clockwise direction.

A potentiometer 40 is mounted on the end of shaft 8 and, as more fully explained hereafter, the change in the ratio of resistances in potentiometer 40 upon rotation of shaft 8 may be measured by a recorder to record the position of the screw and thus the position of the adjustment mechanism operated by the screw.

Actuators constructed as shown in FIGS. 2-4 have a number of advantages. They require small space and may be conveniently placed over the complete width of a paper machine to handle a plurality of adjustments, for example, moveable slice lip adjusting mechanism, cross-machine moisture control mechanisms, or crossmachine caliper control mechanisms. The actuator controls for energizing the solenoids may be positioned at any convenient station. The amount of adjustment upon each energization of a solenoid is not dependent upon the length of time that the solenoid is energized since the pawl driving the ratchet wheel will advance the ratchet only one tooth length upon each energization of the solenoid. This results in a more precise control of the adjustment mechanism since the operator will know that upon each energization of the solenoid (i.e. each activation of a control button) that the adjustment screw will rotate a predetermined amount. Further, the actuators are easily adaptable for use with computers since the solenoids are responsive to electrical pulses easily controlled by a computer. Also, because a screw adjustment is used and because the number of teeth on a ratchet wheel may be easily varied, the degree of adjustment may be kept within extremely close tolerances which when used with a slice adjustment is an important feature.

It is desirable that the position of each individual adjustment screw be read at a station remote from the adjustment screws and preferably at the station where the control for the adjustment is maintained. Referring to FIG. 4, there is illustrated a portion of an electrical circuit connecting a plurality of potentiometers 40 contained on the end of each of the screw adjustment shafts 8 to a single recorder 41. The recorder 41 may be of the type having a recording pen 42 which is moveable with respect to a graph in the recorder in a vertical direction along a Y axis, and in a horizontal direction along an X axis. Conventional electrical means, not shown, are included in the recorder which are responsive to signals received from leads 43, 44, and 45 which connect one side of a rotary stepping switch having a plurality of switch levels. In FIG. 4, only three levels A, B, and C are illustrated. Each level contains a plurality of contacts over which a wiper arm 46 passes. As shown in FIG. 4, leads of the recorder are connected with leads extending to the individual potentiometers by the wiper arm in levels B and C. In FIG. 4, only twenty-six or half of the contacts of a particular level are shown, it being understood that the same wiper arm passes over similar contacts contained in the other half of the level. Thus, the stepping switch diagrammatically illustrated has a total of fifty-two contacts on each level.

Each of the potentiometers 40 is connected to the stepping switch by means of leads 47 and 48 such that when the wiper arm is on contact No. 4 shown in FIG. 4, lead 47 is connected to the recorder through level C while lead 48 is connected to the recorder through level B. A permanent common lead 44 connects the recorder with the potentiometers at all times. As the shaft 8 is rotated to raise or lower the slice lip, the center lead 48 of the potentiometers changes position to thus send a signal via the stepping switch to the recorder.

The movement of the wiper arm 46 of the switch is controlled by level A as well as by a demand switch, a left limit switch, and a microswitch as shown in FIG. and as explained more fully hereafter. The wiper arm 46 of level A will advance from one contact to the next only as the switch coil 50 receives an external pulse which occurs only when the wiper arm is on a contact so that a pulse can reach the switch coil. The pulses to advance the wiper arm come from the demand switch, the left limit switch or from the microswitch 51, all of which are connected to a power source. Switch 51 is actuated by a toothed wheel 52 contained on a drive shaft which drives the indicator pen 42 of the recorder along the X axis. Microswitch 51 is continuously being tripped but it is only connected to certain contacts of level A of the stepping switch, namely contacts 2-24 and 28-50 (not shown).

Before the demand switch is actuated, the recorder 41 is normally recording web characteristics, for example, basis weight of the web and the wiper arms are either on contacts 26 or 52. This measurement is made by having a conventional basis weight measuring device move across the web and the device is connected to the electrical means moving the Y axis of the indicator pen 42 so that the pen indicates basis weight of those portions of the web beneath the basis weight measuring device. When recording basis weight, the indicator pen moves from the left side of the chart, as shown in FIG. 6, to the right side marking the basis weight on line 60. When the pen reaches the right side, it then draws a desired or target basis weight line 61 from right to left. When the pen reaches the left side of the chart, the chart is moved downwardly along the Y axis so that the indicator pen is repositioned relative to the chart to make a new recording of basis weight.

The sequence of operation when it is desired to record the position of screws 8 on the recorder 41, or as shown in the drawings, to record the position of the slice lip, is as follows. The demand switch is operated. This will impart a pulse to the coil 50 to advance the wiper arm from either contacts 52 or 26, the home contacts where the recorder normally records basis weight, to either of contacts 1 or 27. In this position of the wiper arm, the recorder pen is still recording basis weight. When the pen 42 reaches the left side of the chart, a left limit switch will operate, thus imparting another pulse to the coil 50 to advance the wiper arm to either of contacts 2 or 28. In this position of the wiper arm, the first of the potentiometers 40 will be connected with the recorder so that the pen 42 will mark the slice lip position of the lip portion to which the screw 8 is connected. This will appear as line 62 on the chart as shown in FIG. 6. As the pen is moved along the X axis by the shaft driving it, toothed wheel 52 will trip switch 51 to impart a further pulse to coil 50 and so advance the wiper arm to either contact 3 or 29 where the second potentiometer is connected to the recorder. This procedure keeps up until the wiper arm advances to contacts 25 or 51 where the twenty-fourth or last of the slice lip positions is measured. The recorder pen then hits the right limit of the chart and returns to the left side drawing a reference line 63 of the slice lip position until the pen reaches the left limit of the chart. At this point a left limit switch is operated to impart a pulse to the coil 50 to move the wiper arm to either contact 26 or 52, the home position where the recorder again records basis weight.

Other levels of the multi-level rotary stepping switch operate relays to switch the recorder from basis weight to slice; screw position and to adjust the gain in the recorder when going to slice lip measurement.

As seen by reference to FIG. 6, the inclusion of measurements relating to web characteristics such as basis weight on the same chart as measurement of the adjustment mechanisms which vary the web characteristics, for example slice lip position, result in a convenient visual comparison of the adjustment means with the web characteristics. This aids the machine operator in making the proper adjustments to insure that the web being produced will have the desired characteristics.

The use of the particular actuators with a recording means as disclosed results in a system which is adaptable for use with computers to insure rapid and automatic regu lation of the slice lips. A computer may be conveniently programmed such that it may measure differences in web characteristics from a desired characteristic and impart electrical pulses to an actuator means to vary an adjustment means to make the desired correction. For example, the computer could measure the difference between actual weight of a portion of a web with the desired web and impart a pulse to a solenoid 24 to automatically make the desired adjustment to a slice lip.

While we have described our actuator and recording system with reference to slice lip control, it is apparent that it could be used for other controls in a paper machine, such as the control of moisture across the web of the paper where screw means could be used to regulate valves across the machine and where the recorder would normally record moisture content of the paper being produced.

We claim:

1. In a paper machine slice mechanism having a movable slice lip for controlling flow of wood pulp from a head box and a plurality of slice screws for raising and lowering portions of said lip with a screw connected to each said portion, the improvement comprising having a first and a second actuator operatively connected with each said screw whereby one said actuator causes the screw to rotate in one direction to raise a lip portion and the other actuator causes said screw to rotate in an opposite direction to lower said lip portion; each said actuator comprising a toothed ratchet wheel on said screw, a pawl associated with each said ratchet wheel and adapted to engage with a tooth thereof, and a movable solenoid armature operatively connected to each said pawl for moving a pawl into engagement with a tooth of the ratchet wheel to rotate the wheel and screw one tooth length.

2. A paper machine slice mechanism according to claim 1 wherein the improvement comprises in addition having the pawl of each actuator rotatably mounted on a first link with one end of said first link pivotable about an axis concentric with a ratchet wheel, a first toggle link having one end pivotably mounted to the end of said first link opposite said ratchet wheel, a second toggle link having one end pivotably mounted with respect to said machine and its other end pivotably mounted to an end of said first toggle link such that said first toggle and second toggle links together form a toggle joint, and the solenoid armature of said actuator connected at the jointure of said first toggle and said second toggle links such that movement of said solenoid armature way from said ratchet wheel moves said toggle links away from said wheel to turn said first link about said wheel and to bring the pawl mounted thereon into driving engagement with a tooth of the ratchet wheel.

3. A paper machine slice mechanism according to claim 1 wherein the improvement comprises in addition having a recorder means for recording basis weight across the width of the web of paper produced by said machine and slice lip positioning indicator means associated with said recorder means whereby the position of each slice lip portion may be indicated on said recorder.

4. A paper machine slice mechanism according to claim 3 wherein said recorder has an indicator pen moveable in two directions at right angles to each other to mark along X and Y axes of a chart the basis weight extending across a web of paper produced by said machine, electrical means for moving said pen, a rotatable drive shaft for moving said pen laterally with respect to said chart along the X axis, a microswitch actuated by rotation of said drive shaft, a rotary stepping switch operated by actuation of said microswitch whereby each actuation of the microswitch advances the stepping switch one step, a potentiometer associated with each said slice screw and being operable by rotation of said screw, leads connecting each said potentiometer with said stepping switch, leads connecting the electrical means for moving said indicator pen with said stepping switch, a rotary wiper arm in said stepping switch for connecting the leads of a single potentiometer with the leads of said electrical means moving said indicator pen, a demand switch for initially actuating said stepping switch and means in said stepping switch for disengaging said recorder from recording basis weight after the pen has moved to the limit of its travel along the X axis; said References Cited UNITED STATES PATENTS 3,000,438 9/1961 Alexander 162259 3,413,192 11/1968 Beecher 162259 3,463,701 8/1969 Curtis l62259 X REUBEN FRIEDMAN, Primary Examiner T. A. GRANGER, Assistant Examiner

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