US3813285A - Paper machine headbox slice opening gauge - Google Patents

Abstract

A portable apparatus readily attachable onto the adjusting screws of a conventional paper machine headbox for producing the cross-direction profile of a paper machine headbox slice opening accurately and with sufficient repeatability so as to render the measurement dependable within the limits required for the manufacture of a high quality paper web.

Description

MG) 28, 1974 v V I c SHELQR 3,813,285

PAPER MACHINE HEADBOX SLICE OPENING GAUGE Filed July 20, 1973 4 ShbBiS-Shfist l FEW F166 mil C. D. SHELOR PAPER MACHINE HEADBOX SLICE OPENING GAUGE May 28', 1974 4 Sheets-Sheet 2 Filed July 20, 1973 FIGZ y 28, 1974 c. D. SHELOR 3,813,285

PAPER MACHINE HEADBOX SLICE OPENING GAUGE Filed July 20, 1973 4 Shoots-Shoot 5 May 28, 1974 c. DSHELOR 3,813,285

PAPER MACHINE HEADBOX SLICE OPENING GAUGE Filed July 20, 1973 4 Sheets-Sheet 4 United States Patent 3,813,285 PAPER MACHINE HEADBOX SLICE OPENING GAUGE Clifford D. Shelor, Tyrone, Pa., assignor to Westvaco Corporation, New York, N.Y.

Filed July 20, 1973, Ser. No. 381,270 Int. Cl. D21f 7/06 U.S. Cl. 162-263 4 Claims ABSTRACT OF THE DISCLOSURE A portable apparatus readily attachable onto the ad justing screws of a conventional paper machine headbox for producing the cross-direction profile of a paper machine headbox slice opening accurately and with sufficient repeatability so as to render the measurement dependable within the limits required for the manufacture of a high quality paper web.

THE BACKGROUND OF THE INVENTION 1. Field of the invention The present invention relates to the headbox of a paper machine and more particularly to a device for measuring the slice opening of a headbox.

2. Descritpion of the prior art In a fourdrinier machine, the paper stock is discharged from the headbox onto the forming wire through a slice opening, which controls the rate of flow and the amount of stock being deposited on the wire at any particular time. In order to produce a web paper having uniform specifications across its entire width as required by todays paper market, the headbox slice opening must be maintained at a constant cross-sectional area. The maintaining of a slice opening at a constant cross-sectional has been a continuing problem in the papermaking industry for many years. The problem in this area, however, has been greatly amplified because of the economic demands to run more paper per machine, per hour, and to increase the width of the paper web.

The slice opening of a paper machine consists of an upper lip and a lower lip, each extending the entire width of the headbox. The upper lip, usually in the form of a hinge supported from the front wall of the headbox, and the lower lip usually an extension in the form of an apron extending from the bottom of the headbox. The slice opening is'usually positioned over the breast roll of the fourdrinier Wire. The apron extending over the breast roll is usually thin in an effort to discharge the slurry onto the wire without a drop off. Normal procedure for the papermaking technician is to adjust the upper lip when the quantity of stock flowing from the headbox onto the fourdrinier wire is increased. This, of course, is one of the methods by which the thickness of the paper being manufactured can be increased and still maintain the speed of the wire at its normal rate.

It should be noted at this point that the requirements of maintaining the slice opening constant across the entire width of the headbox is a very difficult specification to meet. Some of the reasons for the difficulty are because of the great magnitude of the width. The upper and lower lip are susceptible to the structural deflection, warpage and creep.

It has become a custom in the papermaking industry to take periodic readings in various places of the width of the slice opening. The terminology for such a meas urement is a cross-direction profile. The cross-direction profile can be taken, for example, from left to right at predetermined intervals across the width of the paper machine. The measurement is made of the space between the lower lip and the upper lip. The usual method. of

analysis of the measurement once'recorded is a graphic plot, The horizontal axis of the graph usually represents the width of the headbox and the vertical axis represents the upper lip height above the apron' at any particular point. The difiiculty in maintaining a rigid, invariable opening of the slice isa result of the flexibilityof the steel lip, the structural deflection caused by the weight of the stock slurry in the paper machine headbox and the warpage as a result of increase and decreasing temperature of the paper stock.

In the past, the measurement of the slice opening has been accomplished with various pieces of equipment. The most notorious objection to prior art devices'is the re-' quirement for the paper technician to develop a feel for taking the reading in order to get reproducibility in reading the points across the face of the slice opening under operating conditions. The technician must develop a feel for maintaining a constant pressure of the gauge against the upper lip and against the lower lip in order to get reliable readings. The constant pressure is not easily. attainable because of the hydraulic noise andvibration in the general area of the slice opening.

Another, less notorious, objection is that the instrument must be readily portable in order to be moved from point-to-point to take the reading. However, in making such an instrument readily portable, the vibrations, as noted before, become an increasing obstacle to data reliability.

It is, therefore, an objective of the present invention to provide a steady, accurate, easily read display of the measurement data.

Another object of the present invention is to provide an instrument that will lessen the possibility of the measuring implement, namely the measuring probe, for contacting the fourdrinier wire. It should be pointed out at this time that any contact with the wire may cause damage thereto and result in streaking the paper product.

In addition, it should be pointed out that should an instrument become entangled in the wire, a very costly accident would result usually requiring the replacement of the fourdrinier wire. Another object of the present invention is to provide an apparatus for maintaining a constant pressure on the probe device during measuring the depth to which it has been depressed. This, of course,

eliminates the skill of the technician and produces repeat ability in data taking.

SUMMARY OF INVENTION The present invention consists of an instrument used in measuring the slice opening of a headbox to produce a cross-direction profile. It is light enough to move manually from point-to-point across the lip of the headbox.- In addition, it is built to withstand the vibration inherent to measuring the slice opening of a conventional paper out at this time that inserting the probe into the slice opening is effected by the paper stock flow characteristics around the probe as the stock flows from the headbox onto the wire. As pointed out before, the stock flow is flowing out of the slice opening and the probe is being inserted into the slice opening.

Various other objects, distinctions and advantageous features of the present invention will become apparent from the description of the preferred embodiment below.

. 3 BRIEF DESCRIPTION OF THE DRAWING is a side view of the slice measuring gauge illusillustrating the attachment of the slice measuring gauge to,

the existing adjusting rods and illustrating the, location of the positioning plate in its normal operating mode.

FIG. 5 is a top cutaway view illustrating cross-section III-III illustrating the attachment of the indicating arm. 1" FIG. 6 is an isometric of the probe shaft assembly illustrating the rigid elements thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT -The present invention relates to a portable apparatus for gauging the cross-directional slice opening of a paper machine headbox. Referring to FIG. 1, the structural support of the present invention comprises a channel 17, the upper end of which is equipped with a gauge pivot block 11, the lower end of which is supplied with a gauge glide 15. The gauge glide 15 is provided with a gauge rest 16 and a positioning plate 14. Pivotally mounted from the gauge pivot block 11 is a gauge tube 12 enclosing a shaft 18. The shaft 18 is coaxially positioned within the gauge tube 12 by the upper bearing housing 9 and the lower bearing housing 13. Attached to the lower end of the shaft 18 is a measuring probe 19. The upper-most extremity of the shaft 18 is provided with an abutment collar 1 securely attached to the shaft by steel pin 21.

Also secured to shaft 18 is indicator bracket 5 which includes the indicator plate 6. A suitable dial indicator 27 having a 1 inch capacity, for example, is adjustably mounted on the plate 6 for selective positionment along a line parallel with the shaft 18 axis.

Indicator arms 4, 4' are bell-crank elements having the elbows thereof pivotally secured at 63 and 65 respectively to the indicator plate 6. The long link of the upper indicator arm 4 is pivotally secured to the actuator 2, to be described subsequently, whereas the long link of the lower indic9ator arm 4 is pivotally secured to the bearing hous- The short links of the respective indicator arms 4, 4 are shaped to a point. Calibrated quadrants are indieia provided on the plate 6 adjacent to the indicator arm points. The quadrant calibration is merely relative and provided only for convenient comparison of relative angular displacement of the respective arms 4, 4'.

Actuator 2 is a block element provided with a bore to slidably receive the shaft 18 therethrough. For convenience and handling ease, handles 24, 24 are secured to the actuator 2.

Assembled, the actuator 2 is resiliently biased against the abutment collar 1 by coil spring 28. The opposite end of spring 28 rests against bracket 5.

. Spring 29 is disposed between bearing housing 9 and bracket 5 to bias the unit comprising shaft 18 and bracket 5 axially upward.

The rate of spring 29 is slightly greater than that of spring 28 to support the shaft assembly weight at a desired neutral position for bracket 5 axially relative to hearinghousing 9.

Dimensionally, indicator arms 4, 4', springs 28 and 29 and the neutral design position of bracket 5 relative to housing 9 are all coordinated so that indicator arm pointers align with an axis between pivots 64 when in the neutral or unused condition.

) The dial indicator 27 on plate 6 is provided with indicator pointers 59 and 60 on its face. Angle bracket is adjustably secured to the upper bearing housing 9such that'the plunger of the dial indicator 27 rests upon the upper lip of the angle bracket 10.

Lock 8 is used while pivoting the arm from spring 26, 26 to 53, 53'. Its purpose is to locate the height of the probe so that ittouches neither the wire, the lower apron lip nor the slice lip while.being pivoted into place. Sliding contact could nick the slice or damage the probe.

The gauge tube 12 housing theshaft '18 is pivotally secured to the gauge pivot block 11 by journals 31 and 31.

Spring loaded button snaps 53 and 53' are pos tioned on the positioning plate 14 which is an extension to the lower gauge guide 15. Spring loaded button clips 53 and 53 mate with indentations 66 and 66' located in the lower bearing housing 13. By the mating of spring loaded button clips 53 and 53' with indentations 66 and 66' respectively, the measurement probe 19 is held in the correct position of use. Spring loaded button snaps 26 and 26' are also positioned on the lower positioning plate 14 to the right of spring loaded button snaps 53 and 53', as seen in FIG. 1. As a result of the pivoted mount provided at 62 on the upper gauge pivot plate 11, the gauging apparatus, including the gauge tube 12 and shaft 18, can be conveniently held at a more desirable angle relative to the support channel 17 and other mounting structure during the headbox attachment and removal operations. Spring loaded button snaps 26 and 26' are provided to secure probe 19 at awithdrawn position relative to the slice opening. When secured to the headbox structure, the gauge tube 12 and the shaft 18 will be pivotally swung back into the slice opening measurement position provided by spring loaded button snaps 53 and 53'. Held in position by spring loaded button snaps S3 and 53, the measuring probe 19 is in the precise place for measuring the distance between the profile bar 57 and the apron plate 58.

In order to hold the slice opening gauge in position on the headbox structure for taking the measurement of the slice opening, the slice adjusting rod screws are used for support. The adjusting rod screws are equally spaced across the face of most conventional paper machine headboxes. The adjusting screws are supported by the front wall of the paper machine headbox and are used to hold the lip of the slice opening in as static a position as pos-' sible, as well as providing an opening. The'customary location of the adjusting rods are parallel to each other and equally spaced across the width of the headbox.

To accommodate mounting of the invention-to the headbox, the gauge pivot .plate 1 at the uppermost part of the instrument is equipped with spring loaded button snaps 56 and 56' as can be seen in FIG. 3. 'I'he's'pring loaded button snaps 56 and 56" are positioned so as to clip onto any pair of adjusting rods. This securely attaches the upper end of the instrument to the adjusting rods.

In order to maintain the instrument more securely, 'pins 54 and 54', 55 and 55' are positioned opposite andopposed to each other respectively on the lower gauge guide 15, as can be seen in FIG. 4. Pins 54 and 54' are longer than 55 and 55 to enable the instrument to be placed between the rods. In studying FIG. 4, it is observed that the gauge guide 15 can be moved to the left sufiiciently enough for the pins 55 to be clear of the right-hand existing adjusting rod. At this point, the instrument can be rotated clockwise sufiiciently for it to allow pin 55 to clear the righthand adjusting rod support. Of course, the reverse of this. procedure will allow positioning of the instrument between the adjusting rods. Once the pins, 54, 54', 55 and 55', and spring loaded button snaps 56 and 56' are in position, the instrument is considered securely attached to a set of adjusting rods. In conventional equipment, the adjusting rods are sufficiently long to allow the ,technican to attach the instrument at a higher level than the actual position over the profile bar 57 to which it must eventually be placed to efiectuate a measurement of the slice .open-:

ing. The attaching of the mechanism at'a high level is advantageous from an operational standpoint, as well as ease of-operation and security against falling into the wire. Now the instrument can be lowered against the profile bar 57.

The upper portion of the instrument is provided with a visual indication of the slice opening consisting of a dial indicator 27 and a pair of indicator arms 4 and 4'. These items can be best seen in FIG. 2. The upper indicator arm 4 is pivotally mounted at point 63 to the indicator base plate 6. The extreme left end of the upper indicator arm 4 is pivotally mounted to the actuator at 64. The lower indicator arm 4' is pivotally mounted to the indicator base plate 6 at point 65. The extreme left end of the lower indicator arm 4' is pivotally mounted to the upper bearing housing 9 at point 66.

The procedure for using the instrument is as follows: Position the mechanical lock 8 so that it limits the downward movement of the measurement probe 19 which is attached to the shaft 18 and in turn, into the indicator bracket 5, and the indicator plate 6. The next step is to rotate the probe arm, including gauge tube 12, enclosing the shaft 18 about the pivot point 62 and away from the support channels 17 until it snaps into the spring loaded button snaps 26 and 26', which are in the remote position from the support channel 17. As noted before, the slice adjusting rods are equally spaced across the front of the conventional machine headbox and attached to the front wall of the headbox. They provide support and adjustment for the upper lip of the slice opening. Assuming the cross-direction slice opening profile is to be taken from the left to the right facing the headbox, the extreme left adjusting rod will be the firstuponwhich the instrument will be mounted. Holding the instrument at about a 45 degree angle, with the front wall paper machine headbox, the back of the instrument towards the front wall of the headbox, the pins 54 and 54 can be positioned over the extreme left adjusting rod. The instrument can then be rotated counterclockwise around the adjusting rod until it is parallel with the front wall of the paper machine headbox. At this point, the instrument can be pushed to the left thereby engaging pins 55 and 55' with the slice opening adjusting rod positioned to the right of the most extreme left side of the slice opening. Now the top portion of the instrument can be pushed forward towards the headbox until the spring loaded button snaps 56 and 56' engage the top portion of the said adjusting rod. Now the instrument is secured to the adjusting rods and can be moved up and down parallel to the adjusting rod. Next, push the instrument down until the instrument base block 16 seats itself on the top corner of the profile bar 57. Push down on the dial indicator bracket 5 until it rests firmly on the stop 8 which is rotated into place at the beginning of this procedure. Holding the dial indicator 5 in the downward position, the probe arm can be moved from the rear button snap positions 26 and 26' to the frontmost button snap positions 53 and 53'. At this point, release the dial indicator bracket 5 allowing the probe 19 to come up until it contacts the bottom edge of the slice profile bar 57. Spring 29 is biased against the indicator bracket 5 such that a predetermined amount of pressure is applied through the shaft 18 to the probe 19, thereby holding the probe against the upper face of the profile bar 57. This step should be repeated gently two or more times to be sure that a repetitive reading can be taken on the dial indicator 27. When repeating these steps, the dial indicator should be watched to see that the pointer 60 comes to rest at the same point after each depression and release of the indicator bracket 5.

Now, set the dial indicator to a zero reading in order to get a relative reading of the slice opening. Turn the outside rim of the dial indicator 27 until the large pointer 60 is at 0. Note, the unit was set up with a small, initial preload on the dial indicator to prevent unmeasured end play of the indicator follower button. Depending on how 6. the instrument is manufactured, the usual preload depression is approximately 0.10 inch, which means that the small point of 59 should read approximately 0.1 inches. If it doesnt, readjust the dial indicator positioned within its slotted mounting on the indicator plate 6. Next, rotate the stop 8 so it will no longer limit the downward move-. ment of the probe 19, its shaft 18 and the dial indicator bracket 5. Next, grip the black plastic handles 24, 24' respectively, and apply a smooth uniform force downward while watching the indicator arms 4 and 4 which are located just to the right of the dial indicator 27. As the movement is continued downward, the indicator arms 4 and 4' will move approximately together. When the bottom indicator 4' stops moving, this indicates that the probe 19 has contacted the bottom of the apron lip 58. Now, continue pushing until the top point of arm 4 has moved about one division as indicated on the indicator plate 6 from the rest position for the lower pointer arm 4'. The separation between the indicator arms 4 and 4', as noted on the indicator plate 6, is directly proportioned to the amount of pressure that is being applied to the probe 19 through the shaft 18, the spring 28, and the actuator 2. At this position, read the dial indicator 27. In order to read the dial indicator 27, the small pointer 59 must be read first and add to it the large pointer 60 reading. For example, the small pointer 59 would possibly be located between 0.5 and 0.6 inches so the reading is 0.5. The larger pointer will give the fraction that should be added onto the small pointer reading of 0.5. Next, read the large pointer. Assuming the large pointer reads .050, this gives a total overall reading of 0.550. The thickness of the probe must also be considered in the preferred embodiment of the present invention. The probe 19 may, for example, be exactly 0.400 inches, therefore, we must add this amount to the reading of the dial indicator. It should be noted at this time that we started with a reading on the small pointer of 0.1 in order to provide a preload on the dial indicator follower button. Therefore, the actual slice opening would be 0.850, the indicator 27 reading, plus 0.400, the-thickness of the probe 19 minus 0.1 inch preload deflection.

After taking a reading, place the stop block 8 back into place. Push down on the dial indicator bracket 5 until it contacts the stop 8. Holding the bracket 5 against the stop 8, snap the probe 19 back out of the slice opening 61 and into the rear spring loaded button snaps 26 and 26'. At this point, release the indicator bracket 5. Lift the gauge several inches off the profile bar 57. Pull the spring loaded button snaps S6 and 56' from around the adjusting rods away from the headbox. Move the instrument to its extreme left, disengaging the pins 55 and 55. Turn the instrument at a 45 angle with regard to the front face of the headbox and disengage the pins 54 and 54' from around the adjusting rods.

This reading is the first point on the cross-direction profile from left to right on a conventional paper machine headbox. The instrument should now be placed in the space provided between the second and third adjusting rods and the procedure above repeated. Next, the procedure should be between adjusting rods 3 and 4, and 4 and 5, and 5 and 6, etc. across the entire width of the paper machine headbox. The points can be plotted on a graph, the abscissa of which represents the width of the headbox and the ordinate representing the height that the slice opening is located above the apron plate. A visual picture of the width of the slice opening above the base plate will be projected by graphs of the cross-direction profile.

Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the description requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative crank elements, said bell-crank elements pivotally seand not in a limiting sense. cured to said pivot support proximate of the bell-crank I claim: elbow, one link of a first bell-crank element being pivot- 1. \An apparatus for measuring the distance between an ally secured to said collar element and one link of the upper slice lip and a lower slice lip of a paper machine other bell-crank element being pivotally secured to said headbox comprising: tubular element.

a frame structure releasably secured to headbox struc- 3. Apparatus as described by claim 1 wherein said first ture; resilient means has a greater spring rate than said second a tubular element secured to said frame structure havresilient means.

ing a rod element disposed axially therethrough, the 10 4. Apparatus as described by claim 2 wherein said bellends of said rod projecting axially beyond respective crank elements each include a pointer portion and said ends of said tubular elements; first and second resilient means are provided with relative an abutment element secured to one end of said rod Spring rates whereby a relative force bias on said probe element; means against said lower slice lip may be determined by a bracket element secured to said rod element between 5 mparing the relative displacement position of said first id abut nt l t d a respgcfive d of id bell-crank pointer portion to the relative displacement pot bu1 l t; sition of said second bell-crank pointer portion when a a collar element disposed about said rod element and displacement force effective to engage Said Probe means i n free l i th id 11 element with said lower slice lip is applied to said collar element. sitioned between said abutment element and said I b k l I References Cited first resilient means compressively disposed between UNITED STATES PATENTS said bracket element and said respective tubular 3,575,799 4/1971 Gedemer at a! element 3 487 686 1/1970 s 1 second resilient means compressively disposed between 3399565 9/1968 omon 162 263 X chmaeng l62263 X said bracket element and said collar element; 2 338 001 12/1943 L displacement measuring means secured between said 2523551 3 33-170 backet element and said tubular element; and pro e means secured to the other end of said rod elev ment for positionment between said upper and lower S- L BASHORE Primary Examiner slice lip and being selectively movably therebetween DKANDREA Assistant Examiner whereby the distance between said upper and lower slice lip may be derived irom said measuring means. 2. Apparatus as described by claim 1 wherein said 33-170, 181 R; 162-198 bracket element comprises pivot supports for two bell- 35 9/1950 Bauer et a]. a 33-l72 R

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