US2576614A

US2576614A - Control for papermaking machines

Info

Publication number: US2576614A
Authority: US
Publication date: 1951-11-27
Anticipated expiration: 1968-11-27

Description

Nov. 27, 195] E. F. LEWELLEN ETAL CONTROL FOR PAPERMAKING MACHINES 6 Sheets-Sheet 1 Filed May 19, 1948 FIG..

INVENTORS EMMONS F.LEWELLEN DARCY E.LEWELLEN ATTORNFYS Nov. 27, 1951 Filed May 19, 1948 E. F. LEWELLEN ETAL CONTROL FOR PAPERMAKING MACHINES Ni ii 6 Sheets-Sheet 2 INVENTO S F. LEWELLEN DARCY E. LEWELLEN ATTORNEYS.

EMMONS Nov. 27, 1951 E. F. LEWELLEN ETAL 2,576,514

CONTROL FOR PAPERMAKING MACHINES Filed May 19, 1948 a Sheets-Sheet 5 INVENTORS EMMONS F. LEWELLEN ATTORNEYS By DARCY E. LEWELLEN' Nov. 27, 1951 E. F. LEWELLEN EI'AL CONTROL FOR PAPERMAKING MACHINES 6 Sheets-Sheec 4 Filed May 19, 1948 INVEN TORS EMMONS E LEWELLEN 3d DARCY E. LEWELLEN ATTORNEYS Nov. 27, 1951 E. F. LEWELLEN ETAL 2,576,614

CONTROL FOR PAPERMAKING MACHINES Filed May 19 1948 s Sheets-Sheet 5 INVENTORS EMMONS F. LWELL EN .DARGY E. LEWELLEN ATTORNEYS Nov. 27, 195] LEwELLEN ET AL 2,576,614

CONTROL FOR PAPERMAKING MACHINES Filed May 19, 1948 6 Sheets-Sheet 6 INVENTORS EMMONS E LEWELLEN B DA'RCY E. LEWELLEN ymflnu'm 696% ATTOR NEYS of paper which is Patented Nov. 27, 1951 2,576,614 CONTROL FOR PAPERMAKING MACHINES Emmons F. Lewellen and Darcy E. Lewellen, Columbus, Ind.

Application May 19, 1948, Serial No. 27,938

Claims.

The present invention deals with paper making machines, and is concerned primarily with the controls employed for the purpose of accurately governing the thickness of paper which is produced by a machine.

In order to clearly set forth the objects and advantages of the present invention, it is necessary to refer to certain essential elements of a paper makin machine of the type with which this invention is concerned. Y

Such a machine ordinarily includes a head box which receives the stock in liquid form and in which the stock is maintained at a predetermined level. The head box is provided with an outlet, the effective area of which is controlled by an adjustable gate. From this outlet a conduit extends downwardly to a manifold. From the latter a plurality of individual conduits extend downwardly to a corresponding number of cylinder vats.

At this point it is well to note that the how of the stock from the head box down through the manifold to the cylinder vats is under gravity action and therefore takes place at a substantially constant velocity.

In each cylinder vat there is a wire screen cylinder together with means for creating a vacuum condition on the interior thereof. The stock is thus drawn to each cylinder and the water exhausted from the center leaving the fibrous pulp on the screen.

The cylinders are power driven and as they rotate the layer of fibers from each cylinder is picked up by a felt in on which the several layers are superimposed to make up the paper thickness. From this felt the sheet of paper is transferred to a second fell; on which it is subjected to the action of pressing rolls which eliminate a large amount of the water so that when the paper sheet leaves this second felt it has a self-sustaining body. It is then passed on through drying and calendering rolls from which it is either cut into sheets or wound into rolls.

It is evident that the thickness of the sheet produced by the machine may be determined by the thickness of the sheet as it leaves the second felt in which it has achieved a self-sustaining body formation and before being subjected to the action of the drying and calendering rolls.

For many years it had been the practice in this art to determine the thickness of paper which was being produced by a machine by the socalled cut and try methods. This means that the form of an endless belt the machine was operated to produce a sheet of paper. If this sheet was found to be too thick the gate controllin the outlet in the head box was adjusted to reduce the effective area of the outlet and thereby decrease the amount of stock which was delivered to the cylinder vats. If the sheet was too thin the effective area of the outlet was enlarged to increase the supply of stock; and these operations were repeated until the paper of a desired thickness was being producedby the machine. Obviously, such methods involved considerable waste and those engaged in paper making production have long since discarded such cut and try methods.

Some years ago it was proposed to obtain a better control of the thickness by locating caliper rolls at the point where the its self-sustaining body were tied up with gate that if the paper sheet too thick the gate would automatically close, or, if it were too thin the gate would automatically open. However, with such an arrangement it was impossible to obtain an accurate control of the paper thickness because of the time period which elapses from the moment the stock passes the gate until it reaches the caliper rolls. Thus, if the paper were too thick and the caliper rolls affected the gate adjusting mechanism so as to move the gate in a direction restricting the size of the opening, this action of the caliper rolls would not cease until the paper reaching them had been reduced in thickness to that for which the machine had been and these caliper rolls adjusting mechanism so terminated soon enough and the gate will close too far to cause the paper to be thinned out beyond the degree desired.

The problems and conditions attending this time factor have been recognized by thoseskilled in this art and et al., 1,768,088 there in the patent to Lewellen is disclosed certain control devices which accommodate this time factor. In this patent a control device is provided which imparts a certain amount of movement to the gate for each cycle of operation. The time period of each cycle is theoretically supposed to correspond to the time which it takes the stock to travel from the outlet of the head box to the caliper rolls. However, in the device of the patent the mechanism which determines the length of a cycle is driven from an idler roll which is in turn driven at a speed commensurate with the speed of travel 01' the paper in the machine. While a device such paper first achieves reaching these rolls were adjusted. Therefore, the closing movement of the gate will not have been as shown in the patent may be adjusted to give accurate and completely satisfactory performance for one speed of operation of the machine, it is not susceptible of adjustment to other speeds and still afford the same satisfactory operation. This is due to the following reasons:

Paper making machines of the type with which this invention is concerned which are actually used by those engaged in the manufacture of paper, are intended to operate at speeds over a fairly wide range. For exemplary purposes, it may be assumed that a machine of this type is designed to afford satisfactory operation over a range of to 80 feet a minute. The velocity at which the sheet moves from the first cylinder in the cylinder vats to the caliper rolls is the speed of the machine and is subject to this variation. However, it will be recalled that the velocity of the stock in its travel from the head box outlet to the cylinder vats is substantially constant. Thus, the time required 9 for the stock to travel from the head box outlet to the caliper rolls comprises a constant plus a variable. The constant is the time it takes the stock to reach the first cylinder vat, and the variable is the speed of the machine. The constant may be represented by the letter a: and the variable by the letter 3 If the control device is adjusted so as to give proper controlling action for a given speed, the cycle would be equal to a: plus y. Let us assume that the speed of the machine is doubled. Under this condition the proper period for the cycle should be az+ /211 and not (:c+y). In the device of the patent above referred to the latter condition obtains and in accordance with the present trend of using high speed machines including a comparatively large number of cylinders, cylinder vats, drying and calendering rolls, it has not proved to be satisfactory.

With the foregoing conditions in mind, the

present invention has in view as its foremost objective the provision of a paper making ma-f chine of the type indicated which includes con-" trol mechanism for accurately controlling the thickness of the paper being produced and. which mechanism is characterized as being capable of accurately conforming to the time interval required for the stock to travel from the outlet in the head box to the caliper rolls.

A further object of the invention is the pro: vision in a paper making machine of the type indicated of control mechanism which is either manually adjustable or automatically operable to control the thickness of the paper being produced over a wide range of speeds for the paper making machine.

In carrying out these ideas in a practical embodiment the control mechanism includes certain instrumentalities which determine the length of the cycle which provides for the intermittent operation of the gate and these instrumentalities are not directly commensurate with the speed of operation of the machine, but are driven by an independent power source such as an electric motor. A somewhat more detailed object of the invention is the provision of means for the manual adjustment of this power source to vary the cycle.

A further object is the provision of means for automatically varying the length of the cycle in accordance with variations in the speed of the machine but in which the cycle accurately conforms to the time required for the stock to travel from the head box outlet to the caliper rolls.

Various other more detailed objects and advantages of the invention such as arise in connection with carrying out the above noted ideas in a practical embodiment will, in part, be-- come apparent and, in part, be hereinafter stated as the description of the invention proceeds.

The invention therefore comprises control mechanism for paper making machines of the type above indicated and which is characterized as being capable of adjustment over a wide range of speed of operation for a machine and at the same time intermittently ad usting the gate over a cycle the length of which accurately conforms to the time it takes the stock to travel from the head box outlet to the caliper rolls.

For a full and more complete understanding of the invention reference may be had to the following description and accompanying drawings in which:

Figure l is a perspective view of the head box and manifold which may be taken as the beginning of the paper making operation for the purposes of. this specification;

Figure 2 is a side view in elevation, but somewhat diagrammatic, bringing'out the manifold, cylinder vats, and associated'parts which bring the paper sheet into a self-sustaining body condition;

Figure 3 is a side view similar to Figure 2 showing the remainder of the machine including the drying rolls, calendering rolls, and cutting mechanism;

Figure 4 is an enlarged detailed showing, partly in section and partly in elevation, of the gate controlling unit;

Figure 5 is an enlarged detailed sectional view 'taken about on the plane represented by the line 5-"5 on Figure 4;

Figure 6 is an enlarged detailed perspective I l of the caliper rolls and control mechanism immediately associated therewith;

Figure 7 is another detailed showing in elevation with parts broken away and shown in section of the contacts of the control mechanism of Figure 6;

Figure 8 is a detailed sectional view through the contacts taken about on a plane represented,

by the line 8-8 on Figure 7; Figure 9 is an enlarged detailed perspective of I the cycle determining mechanism that is manual- 1y adjustable;

Figure 10 is another detailed perspective showing a modified form of cycle determining mechanism which is automatic; and

Figure 11 is a wiring diagram bringing out the manner in which the various control mechanisms are electrically interconnected and tied up with the operation of the machine.

General assembly The general assembly of the machine is depicted in Figures 1, 2 and 3. A head box is shown in Figure 1 and is represented in its entirety by i the reference character B.

pipe is.

Stock in the usual liquid formation comprising water and fibers is introduced into the box B through the inlet pipe shown at l6. This stock is maintained at the level represented by the broken line H as this level is determined by the position of the overflow opening l4.

A manifold is represented at I8 and a conduit l9 extends downwardly from the outlet H to the top of the manifold. Mounted within the manifold is a screen 28 through which the stock must pass. The bottom wall of the manifold I8, which is designated 2 I, is formed with a plurality of out let openings with which communicate

conduits

22, 23, 24, 25 and 26.

Upon referring now more particularly to Figure 2 it will be noted that there is an assembly of cylinder vats comprising the

vats

21, 28, 29, 30 and 3|. The top wall of each vat is formed with an opening with which communicates one of the conduits 22 to 26, inclusive. Thus, the conduit 22 communicates with the opening in the top wall of the vat 21; the conduit 23 with the opening in the top of the vat 28; the conduit 24 with the opening in the top of the vat 29; the conduit 25 with the opening in the top of the vat 38; and the conduit 28 with the opening in the top of the vat 3|.

It is evident that stock flows from the Outlet I in the head box B down through the manifold and conduits above described to the vats 21 to 3|, inclusive, under gravity action. Rotatably mounted within the vat 21 is a cylinder 32 that is of a construction well known and conventional in this art. The cylinder 32 comprises appropriate supporting structure in the form of spiders and on which is mounted a cylindrical screen. At each end there is a head and one of these heads is formed with an exhaust opening 33. A roll shown at 34 cooperates with the cylinder 32 in that a felt 35 is passed between the roll 34 and the cylinder 32.

As the stock is introduced into the vat 21 it passes around the outside of the cylinder 32. A suction is created at the exhaust port 33 and this draws the water into the interior of the cylinder leaving the fibers on the screen. As the cylinder is rotated the layer of fibers so formed is picked up on the underface of the felt 35.

The vat 28 has rotatably mounted therein a cylinder 36 formed with an exhaust port 31 and with which cooperates a roll 38. These elements are the exact counterpart of the elements 32, 33 and 34 in the vat 21 and operate in the same manner.

Likewise, the vat 29 has rotatably mounted therein a cylinder 39 having an exhaust port 40 and with which cooperates a roll 4 These members function in the manner described.

Similarly, the vat 30 is provided with a cylinder 42 having an exhaust port 43 and with which cooperates a roll 44.

Finally, the vat 3| is provided with a cylinder 45 having an exhaust port 46 and with which cooperates a roll 41.

The end wall of the vat 21 is formed with an opening 48 and mounted in this opening 48 is a roll 49. The felt 35 passes between the roll 34 and cylinder 32 and thence over the roll 49. The top wall of the vat 3| is formed with an opening 50 and the felt 35 passes through this opening and then between the roll 41 and cylinder 45. It will be noted that the partitions separating the several vats are formed with horizontal slots through which the felt 35 passes.

, The felt 35 takes the form of an endless belt.

6 After passing over the roll 48 it passes beneath a pressure roll 5| and from there upwardly over a. roll 52. From the roll 52 the belt continues back over another roll 53 after which it passes down through the opening 50.

After the lower ply of the felt 35, that is the ply which passes through the several cylinder vats, passes over each

cylinder

32, 36, 39, 42 and 45, it is urged thereagainst by the rolls 34, 38, 4|, 44 and 41, and this underface of the felt picks up the layer of fibers which has formed on the cylindrical screen surface of each cylinder. These layers are superimposed one upon the other to form the thickness of the paper sheet being produced.

A second felt is represented at 54 and also takes the form of an endless belt that passes over pressure rolls 55, 56 and 51 and over the guide rolls 58 and 59. It will be noted that this felt 54 at the roll 5| passes beneath the felt 35. Thus, the sheet of paper which has been built up on the underface of the felt 35 is transferred to the upper face of the felt 54. Cooperating with the pressure roll 56 is a complementary pressure roll 50. As the paper sheet on the felt 54 passes between the rolls 56 and 60 a substantial amount of the water is squeezed therefrom and this action is repeated as the paper sheet passes between the pressure roll 55 and a complementary pressure roll 6|.

As the paper sheet leaves the bight of the

rolls

55 and 6| it will have achieved a self-sustaining body. This paper sheet is represented at P and is shown as passing over guide rolls 62 and 63 and thence between a pair of caliper rolls 64 and 65 which form a part of a control unit represented at C, to be described later in detail.

After passing between the caliper rolls 64 and 65 the paper P is passed over a series of drying rolls shown at 66, 61, 68, 69, 10, 1|, 12, 13 and 14. It'is to be understood that the invention is not to be limited to the particular number of drying rolls illustrated, because this number may be varied in accordance with principles well known in this art.

After leaving the drying roll 14 the p per P is passed between a series of calender rolls. These are shown at 15, 16, 11, 18, 19, 88, 8|, 82, 83, 84, and 86. From the last calender roll 86 the paper P passes over a guide roll 81 and thence to a cutting machine represented diagrammatically at 88. This cutting machine cuts the paper into sheets which are stacked as indicated at 89. It is evident that the cutting machine 88 and stack 89 could be replaced by a rolling device which would simply roll the paper P after it leaves the uide roll 81 into a rolled formation.

It is evident that after the paper sheet P leaves the

rolls

55 and 6| it has a self-sustaining body and will have achieved its thickness. Thus, when this sheet passes between the caliper rolls 64 and 65 any variations in the thickness thereof will be effective through the several control units now to be described to adjust the gate l2 so as to vary the effective area of the outlet I. These control devices will now be described.

Gate operating mechanism As shown in Figure l, a unit U is mounted on the top of the box B and extending downwardly from this unit U is a link 98 that is connected to the gate l2. The mechanism of the unit U is effective through this link 90 to raise or lower the gate l2. 7

Referring now more particularly to Figure 4, it

will be noted that the unit U comprises a casing defined by side walls 9| and 92, a top wall 93, and a bottom wall 94. The top wall 93 includes an arched part 95 which accommodates the extension of the side wall 92. Extending downwardly from the joinder of the arm 95 and top 93 is a vertical partition 95 that is integrally connected at the bottom with a horizontal partition 91. Another horizontal partition 98 extends between the vertical partition 96 and the side wall 92, and another comparable horizontal partition is shown at 99.

Mounted on the partition 91 is an electric motor I having a drive shaft IOI on which is drivingly mounted a worm I02. Meshing with the worm I02 is a worm gear I03 that is drivably mounted on a shaft I04. The shaft I04 is journaled in the partition 96 and at the end remote from the worm I03 drivingly carries a bevel gear I05. A vertical'shaft I06 is journaled in the

horizontal partitions

98 and 99 and drivably mounted thereon is a bevel gear I01 which meshes with the bevel gear I05. Drivably mounted on the lower end of the shaft I06 is a gear I08 that meshes with a pinion I09 that is drivably mounted on a screw stem H0. The screw stem H0 is arranged vertically and has its opposite ends journaled in the partition 91 ,and bottom wall 94, respectively. Threaded on to the screw stem H0 is a nut III from which projects an arm I I2. It will be noted that the link 90 is pivotally connected at its upper end to the arm II2 with the pivotal connection being shown at II3. This link 90 passes through an opening II4 formed in the bottom wall 94.

Extending outwardly from the nut III in a direction substantially opposite to the arm H2 i a second arm II5. This arm may be formed with an opening through which passes a vertical guide rod II6 having its upper and lower ends anchored in the partition 91 and bottom wall 94, respectively. A slide rod II1 has its lower end slidably received in an opening II8 formed in the bottom wall 94 and adjacent to its lower end carries a collar II9. An expansion coil spring I20 bears against the collar H9 at the top and the wall 94 at the bottom. The upper end of the slide rod H1 is reduced in diameter as shown at I2I and is slidably received in an opening I22 formed in the partition 91. This opening I22 is counterbored as indicated at I23 and an expansion coil spring I24 is disposed around the reduced end I2I within the counterbore I23.

It is evident that the springs I20 and I24 normally maintain the slide rod H1 in a neutral position but permit a certain amount of sliding action on the part of the rod. A collar I25 is mounted on the slide rod II1 on the upper side of the arm II whereby the lower face of the collar I25 is adapted to be engaged by the arm II5. A second collar I26 is mounted beneath the arm II5 whereby its upper face is adapted to be engaged by the arm I I5.

It is evident that as the arm H5 is moved upwardly it will engage the collar I25 to shift the slide rod II1 upwardly, or, as it reaches the lower limit of movement it will engage the collar I26 to shift the slide rod II1 downwardly.

A switch is referred to in its entirety by the reference character S, and is shown as mounted on the inner face of the wall 9|. The switch S comprises a central contact I21 that is carried at the end of an arm I28, an upper contact I29 carried by a spring arm I30, and a lower contact I3I carried by a lower spring arm I32. A

tension spring I39 has its opposite ends connected to the arms I30 and I32 and normally urges the contacts I29 and I3! into engagement with the contact I21. Extending outwardly from the slide rod 1 I1 is an arm I34, the free end of which is disposed between the free ends of the arms I30 and I32.

The switch S is intended to function as a limit switch for the motor I00. When both the contacts I29 and I3I engage the intermediate contact I21, as illustrated in Figure 4, the circuit to the motor I00 is closed so far as the switch S is concerned. Thus, if the nut III should be moved upwardly sufficiently far, arm II5 engages the collar I25 to shift the slide rod II1. This causes a corresponding movement on the part of the arm I34 which will engage the free end of the spring arm I30 and lift the contact I29 from the contact I21 thereby interrupting the circuit to the motor. In the same way, if

the nut III is moved downwardly a suflicient distance the arm H5 engages the collar I26.and shifts the slide rod II1 downwardly, thereby causing the arm I34 to engage the free end of the spring arm I32 and separate the contact I3I from the contact I21 to interrupt the circuit. With this arrangement it is evident that the gate I2 can be neither opened nor closed beyond a certain predetermined extent.

Drivably mounted on the upper end of the shaft I06 is a bevel gear I35 and meshing with this bevel gear I35 is a complementary gear I36 that is drivably mounted on a shaft I31, the opposite ends of which are journaled in the partition 96 and the side wall 92. A disc I38 is drivably mounted on the shaft I31 and the outer face thereof is formed with a raised contact surface I39. Mounted in the side wall 92 is an insulating member I40 in which are imbedded a pair of contacts MI and I42 (see Figure 5), which are connected to the terminals shown at I43. It is evident that these contacts I and I42 are adapted to be bridged and conductively connected by the upraised contact faces I39.

The terminals I43 are connected by cable as shown at I44 to a signal light 2 (Figure 11). Thus, as the motor I00 is operated it will, through the driving connections above described, rotate the disc I39 and upon every full rotation of the disc I 33 the control surfaces I39 will close the circuit to the signal light 2 and thus indicate that the gate I2 (Figure 1) is being moved.

Caliper control unit Upon referring to Figures 6, 7 and 8 the control unit C which is associated with the caliper rolls 64 and 65 will now be described.

Upstanding from the supporting framework of the machine is a stanchion I46 which carries at its upper free end a bracket I41 on which is mounted a panel I48. The panel I48 carries certain mechanism about to be described and which mechanism is adapted to be enclosed by a casing I49 which is hingedly mounted on the panel as represented at I50.

The caliper roll 65 is mounted in fixed position by a clamp I5I that is anchored to the stanchion I46 and from which extends an arm I52 on which the caliper roll 65 is rotatably mounted. The upper caliper roll 64 is rotatably mounted between the arms of a yoke I53, the latter being integrally connected to one leg I54 of a U-shaped plate that is pivotally mounted as represented at I65 on the panel I48. This pivotally mounted as shown the u shaped plate made up of legs I54 and I tact I1I.

U-shaped Plate has a second leg I66. Upstanding from the upper edge of the leg I58 adjacent to its free end is a pointed pin I51 which bears against the. lower edge of a lever I58 that is at I59 on a slide block 9.

The block 9 has a tongue (not illustrated) that is received in a slot 8 and the two cooperate to act as a guide for the block 9 in its sliding movements. A shaft 1 has a lower threaded end that is screwed into a threaded bore in the block 8.

. The upper end of the shaft 1 drivably carries an operating member rotate the shaft 1 and adjust the position of the block 9 and pivot I59 carried thereby. A calibrated cylinder and pointer 4 cooperate to indicate the adjusted position of the pivot I59.

6 which may be availed of to The free end of the lever I58 also carries a pin 3 I 68 that e gages the lower edge of a lever I-6I that is pivotally mounted as shown at I62 on the panel I48. A gear sector I63 is pivotally mounted as shown at I64 on the plate I48 and has a lower face I65 that is engaged by the point of a pin I66 that is carried at the free end It is evident that the several levers comprising I56 and levers I58, I6I and gear sector I63, function as a means for amplifying any movement on the part of the caliper roll 64, which might be caused by variation of thickness in the paper sheet P so as to provide a substantial amount of movement at the gear teeth I 61 on the gear sector I63. A pinion I68 is pivotally mounted on the panel I48 and engages the gear teeth I61 so as to be operated thereby. A contact arm I 69 is drivingly connected to the pinion and the free end of this arm is adapted to engage any of the contacts I 18, HI, and I12. These contacts I18, "I, and I12 are arranged in arcuate formation and immediately above them is a graduated scale I13 which is adapted to cooperate with the arm I69.

A terminal block I14 is mounted on the panel I48. A terminal plate I16 is carried by this block and a conductor I16 connects this plate I with the contact I 18. A cable I11 extends from the plate I15 and is a part of the electrical circuit to of the lever I6I.

be later described. Likewise, another terminal plate I18 is carried by the block I14 and is Joined by a conductor I19 with the contact I1I. A cable I88 leads off from the terminal plate I18. Still another terminal plate I8I is mounted on the block I 14 and is connected by a conductor I82 with the contact I12. A cable I83 leads off from the plate I8I-. A light I84 is mounted on the block I14 and illuminates the interior of this unit. It will be noted that a cable I85 is connected to the contact arm I69 as indicated at I86. A cable I81 which is broken to include the connections for the light I84 branches of! from this cable I85.

1 While the modus operandi of the control unit C is believed to be self-evident from the foregoing description, it may be noted that as the paper P moves between the caliper rolls 64 and 65 and if the thickness is uniform and of the degree required, the caliper roll 64 will remain immovable with the contact arm I 69 engaging the con- This lights up the white light I and indicates that the paper being produced is of the proper uniform thickness. Should the paper become too thick the caliper roll 64 will be moved upwardly. This movement will be multiplied by the levera e mechanism so as to move the gear sector I63 in a counter-clockwise direction. This will rotate the pinion I68 and contact arm I69 in a clockwise direction whereby it engages the 2I8 carries a contact 228. Another tion illustrated for a purpose 1 formed with an contact I12. This will light up the red light shown at I88 in Figure 11 and also bring the motor I88 into operation in a manner to be later described. On the other hand; if the paper should become too thin the caliper roll 64 will lower and cause a movement of the contact arm I69 in a counter-clockwise direction whereby it will engage the contact I18 and light the green light shown at I89 in Figure 11. The motor I88 will also be operated, but in a-reverse direction from that described above in connection with lighting the red light.

Manually adiustable cycle control First referring to Figure 2 it will be noted that the stanchion I 46 carries a control unit referred to in its entirety by the reference character X,

hich is positioned beneath the caliper rolls. This unit may take either the form of the manually adjustable control unit shown in Figure 9, or the automatic control unit illustrated in Figure 10. The manually adjustable unit of Figure 9 will now be described.

A supporting member is shown in the form of a panel I98. Mounted on one face of this panel I98 is an angle bracket I9I providing an outstanding shelf I92. Mounted on the shelf I92 is a motor I93 having a driving shaft I94. Drivingly carried by the shaft I94 is a worm I95 which engages a worm gear drivingly mounted on a vertical shaft I96. Drivingly carried on the upper end of the shaft I98 is a pinion I91 that meshes with a gear I98. The latter is drivingly mounted on the upper end of a spline shaft I99 that splinably engages collar 288. The lower end of this collar 288 carries a friction disc 28I, the peripheral edge. of which is in engagement with the face of a driving disc 282. The latter is drivably mounted on a shaft 283 that is journaled in the panel I98.

It is evident that the speed at which the shaft 283 is driven depends on the radial distance of the disc 28I from the shaft 283. The closer the disc 28I is to the shaft 283 the greater the speed of rotation of the latter, and conversely, the farther the distance of the disc 28I 283 the lesser the speed of rotation. To the end of varying the eflective distance of the disc 28I from the shaft 283 the collar 288 carries a pin 284 outstanding therefrom. This pin 284 is received in a slot 285 which is of the sinuous formato be later described. The slot 285 is formed in an arm 286 that is pivotally mounted as indicated at 281 on the panel I98. The free end of the arm 286 takes the form of an arcuate/segment 288, the peripheral edge of which is formed with calibrations 289 which cooperate with a pointer 2I8 that is carried by the panel I 98. The segment 288 is arcuate slot 2. A headed bolt 2I2 extends through the slot 2" and has its inner end screwed into a block 2 I3 carried by the panel I98. This bolt 2I2.urges a washer 2I4 against the segment 288 and serves to hold the latter in an adjusted'positi'on.

Drivably mounted on the shaft 283 is a cam 2I5 having a peak 2I6. A lever 2" is pivotally mounted as represented at 2I8 on the panel I98 and is biased by a tension spring 2I9. The free end of this lever engages the peripheral surface of the cam H5 and is held in such engagement by the spring 2I9. The opposite end of the lever lever 22I is nivotallv mounted, as represented at 222. on the panel I98. The free end of this lever takes the form of an arcuate segment 223 formed with an arcuate slot 224 and provided with calibrations 225. The latter cooperate with a pointer 226 carried by a block 221 which is mounted on the panel I90. A headed screw 228 passes through the slot 224 and has its inner end anchored in the block 221. The head of the screw 228 clamps a washer 229 against the arcuate segment 223 to lock the lever 22I in an adjusted position. The lever 22I carries a contact 230 which is connected to a cable 23I by a conductor 232. Likewise, the contact 220 is connected to a cable 233 by a conductor 234.

The control unit X is provided for the purpose of determining the length of a cycle. It is to be remembered that when the gate I2 is to be moved, either with a closing or opening movement, it

will move a certain predetermined distance for each cycle. The length of the cycle, in terms of time, should be exactly the time which-it takes the stock to travel from the outlet I I to the callper rolls 84 and 65. One cycle consists of a complete revolution of the cam 2|! or, in other words, a complete revolution of the disc 202. The latter can be driven faster or slower depending on the relative position of the friction disc I with respect to the shaft 203. The latter may be adjusted by loosening the bolt 2 I2 and swinging the arm 205.

It will be noted that the calibrations 209 are uniformly spaced apart. With this arrangement it is necessary that the slot 205 be of the sinuous formation illustrated because adjustment of the arm must accommodate the fact that the stock travels from the outlet II to the cylinder vats at a constant velocity regardless of the speed at which the machine is operating.

The cables 23I and 233 are included in the circuit of the coils 241 and 250 of switches a and b which operate the motor I00. The length of time during which the contacts 220 and 230 remain in engagement determines the duration of operation of the motor I00,for each cycle. This time period during which these contacts 220 and 230 willremain in engagement may be adjusted by varying the position of the arm 22!. This can be done by loosening the headed screw 228 and then again tightening it after the desired adiustment has been made.

The operation of the unit X may be briefly out-' lined by noting that the motor I93 drives the spline shaft I 99, the latter drives the collar 200 and friction disc 20I. The engagement of the peripheral edge of the latter with the disc 202 rotates the disc 202 and the shaft 203. This rotates the cam 2| 5. As the cam 2I5 is rotated in a clockwise direction the lever 2| 1 is raised and at a predetermined point the contacts 220 and 230 en age and complete the circuit. for the motor I00. This engagement is maintained until the end of the lever 2I1 rides OK the peak 2I6. whereupon the lever drops under the influence of the spring 2 I9 and separates the contacts 220 and 230.

Electrical circuit Before describing the electrical circuit it will be noted from Figures 2 and 3 that the machine includes a main drive shaft 235, the speed of operation of which determines the speed of operation of the machine.

The tachometers represented at 236 and 231 in Figure 11 are operated by a magneto 238 which is driven by the shaft 235.

A source of three-phase alternating current is represented at 239 and from this source three

power lines

240, 2 and 242 lead into the machine. A pair of reversing switches are repre-.. sented at a and b and these switches control the delivery of the current to the motor I00. When the switch b is closed the motor I00 is operated in a direction to close the gate I2, whereas, when the switch a is closed the motor is operated in a reverse direction to open the gate l2.

Three main switches are represented at e, f and g. The switch e controls'the circuit to the red light I88 and also the energizing of the motor I00 for operation in one direction as will be later described. Likewise, the switch f controls the white light I45 and when this light is illuminated maintains the circuit to the motor I00 open, while the switch g controls the circuit to the green light I89 and provides for energizing of the motor I00 in an opposite direction from that caused by the switch e.

A relay 'for the switch e is represented at e. A relay for the switch I is represented at f; and a relay for the switch g is represented at g.

Operation The operation of the control mechanism provided by this invention will now be described in conjunction with the manually adjustable unit X.

The caliper roll 64 is first adjusted so that it is separated from the roll 65 a distance exactly equal to the thickness'of the paper which is to be made. This is accomplished by operating memher 6 which, through shaft 1 and block 9, moves the pivot I59. This action moves the lever I58 and thus the U-shaped plate I54-I5'6. As the roller 64 is carried by the arm I54, it is adjusted by this movement. For example, if the paper being made is to be .040 inch in thickness, then the rolls 64 and 65 are set so that they are separated exactly .040 inch. In this position and with paper .040 inch in thickness between the rolls the contact arm I69 is in engagement with the central contact I'll as depicted in Figures 6 and 7.

In this position both the switches a and b are open and no current is delivered to the motor I 00. However, the circuit through the cables I80 and I81 is closed to energize the relay coil 243, thereby closing the relay f and energizing the relay coil 244. This closes the switch 1 and completes the circuit from the power line 2 through switch f to the white light I45. This indicates that the machine is operating to produce paper of the required uniform thickness. While the motor I93 is continuously operating because it is connected across power lines HI and 242 and the contacts 220 and 230 will come into engagement in each cycle, the motor I00 cricuit to the red light I88. At the same time closing of the switch b engages contacts in circuit to coil 241 and upon next engagement of the contacts 220 and 230 the circuit through coil 241 is completely closed, switch b thereby completing the circuit to the motor I00. This causes the latter to be driven in proper operation to move the gate I2 in a closing direction. This movement will continue just as long as the contacts 220 and 230 are in engagement. When the end of the lever 2Il rides off the peak 2I6 of the cam, the contacts 220 and 230 separate and operation of the motor is discontinued until these contacts are again closed. Thus the amount of movement on the part of the gate I2 for each cycle depends upon the period of time in which the contacts 226 and 230 are engaged in each cycle. This period may be adjusted by adjusting the arm 22I as above explained. When the contacts 220 and 230 are disengaged by the arm 2" riding off of the peak 2I6 of the cam 2I5, the red light I88 will continue to be illuminated until the decreased amount of stock flowing to the cylinder vats has reached the caliper rolls in the form of reduced thickness of the paper. At this time the caliper roll 64 will lower and if the adjustment were sufficient to correct the condition of increased thickness, the contact I69 will return to engagement with the contact I'II, thus extinguishing the red light, lighting the white light, and interrupting the circuit to the motor I00. Ii this adjustment of the gate I2 was not sufllcient to correct the condition, then the contact I69 would move over in closer proximity to the contact III but would remain in engagement with the contact In until the next time the contacts 220 and 230 were engaged. At this time the gate I2 would be lowered an additional step and this operation would be repeated until the paper was of the thickness for which the caliper rolls 64 and 65 have been set. Under this condition the contact I69 would engage the contact Ill thereby extinguishing the red light and lighting the white light. If the paper were to become thinner than that for which the caliper roll 64 is set, this roll would fall downwardly thereby moving the contact I69 in a counter-clockwise direction.

This contact would leave the contact I'II thereby breaking the circuit to the white light and engage the contact I10 which would complete the circuit to the green light. This is done by energizing the relay coil 248 which would close the relay 9'. This would in turn energize the 0011 249 of the switch g and thus complete the circuit to the green light I89. At the same time energization of coil 249 engages the contacts in circuit of coil 250 and upon next engagement of the contacts 220 and 230 this circuit would be completed energizing the coil 250 to close the switch g. Thus the circuit to the motor I is completed during that time of each cycle in which the contacts 220 and 230 are in engagement. Thus, the

' gate I2 is moved with an opening movement one step as determined by the time the contacts 220 and 230 are in engagement foreach cycle. When the gate I2 has been opened sufliciently far to achieve the desired thickness in the paper the contact I69 disengages the contacts I10 and moves over into engagement with the contact "I again illuminating the white light.

It is 'evident that when the form of control unit shown at X and illustrated in Figures 11 and 9 is used, any variation in the cycle must be accomplished manually by loosening the bolt 2I2 and moving the arm 206. This may be done by the operator who will make such an adjustment to have the cycle conform to the speed at which the machine is running as indicated on the tachometer.

In the above description of the operation of the control mechanism it has been assumed that one complete cycle exactly corresponds, in theory,

to the time it takes the stock to travel from the gate I2 tothe caliper rolls 64 and 65. As a practical matter this period is subject to some varia- Automatic variation of cycle Figure 10 illustrates a modified form of the control unit X which provides for automatically adjusting the cycle to the speed at which the machine isrunning. The unit for the automatic control is indicated by the reference character Y. It comprises a panel 25I which replaces the panel I60. Outstanding from the face of the panel "I is a bracket 252 in which is journaled a shaft 253. Drlvingly carried at one end. of the shaft 253 is a sprocket 254; a chain (not illustrated) passes over this sprocket 254 and also over a sprocket mounted on the main drive shaft 235. Thus, the shaft 253 rotates at a speed that corresponds directly to the speed of the shaft 235 or, in other words, the speed of the machine. Operatively mounted'on the shaft 253 is a governor mechanism 255 having a movable collar at 256 which is slidable in the shaft 253 and to which is connected a bracket 251.

The latter is in turn connected to one end of a lever 256 that is pivotally mounted as indicated at 259 on the panel 25I. The other end of the lever 258 takes the form of a quadrant 260 that is formed with an arcuate slot 26I. A pin 262 that is carried at one end of a lever 263 projects into the slot 26I. The lever 263 is pivotally mounted as indicated at 264 on the panel 25I and its opposite end is formed with a sinuous slot corresponding to the sinuous slot 205 on Figure 9.

The remainder of the cycle determining mechanism included in this unit is the same as that described above in connection with Figure 9 and these various parts bear the same reference characters.

It is evident that the speed of rotation of the shaft 253 corresponds to the speed at which the paper making machine is operating. Thus, any variations of speed in the latter will affect the governor 255 to cause rectilineal movement on the part of the movable collar 256, This rocks the lever 258 and thereby moves the pin 262 either upwardly or downwardly depending upon whether the machine has been speeded up or slowed down. This causes a corresponding movement at the opposite end of the lever 263 and thus shifts the disc 20! either closer to the shaft 203 Or farther away therefrom to vary the speed of the cycle.

It will be remembered that the basic idea underlying this invention is to have the cycle as determined by the unit Y exactly correspond to the time it takes stock to travel from the outlet of the head box to the calipers 64 and 55. Moreover, the time it takes the stock to travel from the outlet II to the cylinder vats is constant. Thus, the arcuate slot 26I is so designed as to cooperate with the sinuous slot 205 and give just the right amount of movement to the collar 200 and disc 20I upon variations in the speed of the machine. The design of these slots 26I and 205 is simply a matter of engineering to provide the design necessary to accomplish this end. The mode of operation of the machine when the automatic unit Y is included therein is substantially the same as that above given.

While preferred specific embodiments of the invention are hereinbefore set forth, it is to be clearly understood that the invention is not to be limited to the exact constructions, mech-- anisms, and devices illustrated and described because various modifications of these details may be provided in putting the invention into practice within the purview of the appended claims.

We claim:

1. In a cycle control unit for paper making machines; an electric motor, a rotatably mounted cam, driving connections between said motor and said cam, and including means for varying the effective driving ratio, said -ineans comprising a spline shaft, a collar on said shaft, a pivotally mounted lever operatively connected to said collar, means for locking said lever in adjusted position, a friction disc drivingly carried by said collar, a second friction disc engaging the peripheral edge of said first friction disc and drivingly connected 'to said cam, a second pivotally mounted lever having one end engaging said cam, a movable contact on the other end of said lever, a fixed contact spaced from said movable contact, a pivoted arm supporting said fixed contact, and means for clamping said arm in a plurality of positions to vary the length of time said contacts are closed during one revolution of said cam.

2. In a cycle control unit for paper making machines; an electric motor, a rotatably mounted cam, driving connections between said motor and said cam, and including means for varying the effective driving ratio, said means comprising a spline shaft, a collar slidably and drivingly mounted on said shaft, a pin projecting from said collar, a pivotally mounted lever having a slot receiving said pin, means associated with said lever for locking it in adjusted position, a friction disc, a clutch connecting said collar to said cam, a spring biased pivotally mounted lever having one edge engaging said cam, a movable contact on the other end of said levei', a fixed contact spaced from said movable contact, a pivoted arm supporting said fixed contact, a clamp element for clamping said arm, 'and indicia on said arm for indicating its clamped position for a determination of the length of time said contacts are closed during one complete revolution of said cam.

3. In a cycle control unit for paper making machines; a pair of normally spaced contacts, one of which is movable, a source of power, operating connections between said source of power and said movable contact for causing said contacts to engage for a predetermined duration at regularly spaced intervals, said connections including a friction disc, a second friction disc having a peripheral edge engaging the face of said first friction disc, a lever operatively connected to said second friction disc, a pin at one end of said lever, a quadrant having an arcuate slot receiving said pin, a pivotal mounting for said quadrant, an arm rigid with said quadrant, and a governor operatively connected to said arm.

16 achieved a self-sustaining body, a unit at said head box including a motor for operating said gate, a control unit at said caliper roll and including a movable contact operatively connected to said caliper roll, a cycle control unit included in 'the electrical circuit of said contact and said motor, said cycle control unit including means for causing said gate moving motor to operate intermittently at regularly spaced intervals when the thickness of said paper at the caliper roll varies from a predetermined thickness, a governor driven by said machine and including a part movable in response to speed variations of said machine, a lever connected to adjust said control unit to vary the duration of said intervals, a pin in said lever, an arm having an arcuate slot receiving said pin, and means connecting said arm to said part for movement therewith. ,5. A paper making machine comprising a head box having an outlet, a gate controlling the effective area of said outlet, variable speed conveyor means positioned to receive stock from said box by gravity flow and to convey it while draining and forming, a movable caliper roll located at a, point along said conveyor means where the paper has achieved a self-sustaining body and resting on the paper whereby variations in thickness in the paper will cause movement of said roll, mechanism operatively connected to said gate for causing opening and closing movements thereof, the operation of said mechanism being under the control of said caliper roll, and a continuously operating cycle control unit serially connected with said mechanism and including adjustable cycle determining means driven with the conveyor means whereby one cycle of operation of said unit may be adjusted in conformity with the speed of operation of said conveyor means to substantially conform to the time it takes the stock to travel from said outlet to said caliper roll, and means forming a part of said unit manually presettable for causing operation of said mechanism for a predetermined period of time during each cycle.

6. A paper making machine comprising a head box having an outlet, a gate controlling the effective area of said outlet, variable speed conveyor means positioned to receive stock from said box by gravity flow and to convey it by draining and forming into a paper sheet, an electric motor for moving said gate in opposite directions, a continuously operating cycle control unit comprising a pair of normally spaced contacts in the circuit 4. The combination, in a, paper making maof said motor, meansior urging said contacts into engagement for a predetermined duration at spaced intervals including a rotary cam, a variable speed drive connecting the shaft and cam. a shaft for driving said cam and means including a movable member for adjusting said variable speed drive for varying the speed of said cam in accordance with variations in the speed of operation of said conveyor means.

7. A paper making machine comprising a head box having an outlet, a gate controlling the effective area of said outlet, an electric motor for moving said gate in opposite directions, conveyor means positioned to receive stock from said outlet by gravity flow and to convey it while draining and forming into a paper sheet, a caliper roll bearing on the paper sheet at a point along said conveyor means where the paper sheet has a self-sustaining body, a circuit to said electric motor under the control of said caliper roll and including a cycle control unit having an input shaft, a cam, variable speed dl'il ing connections between said shaft and cam, a pivotally mounted lever engaging said cam, a movable contact carried by said lever, a fixed contact adapted for engagement by said movable contact, said contacts being included in the circuit to said motor, and means including a movable arm for adjusting the driving ratio between said shaft and cam in accordance with the speed of operation of said conveyor means.

8. A paper making machine comprising a head boxhaving an outlet, a gate controlling the effective area of said outlet, an electric motor for moving said gate in opposite directions, conveyor means positioned to receive stock from said outlet by gravity flow and to convey it while draining and forming into a paper sheet, a caliper roll bearing on the paper sheet at a point along said conveyor means where the paper sheet has a self-sustaining body, a circuit to said electric motor under the control of said caliper roll and including a cycle control unit having an input shaft, a cam, variable speed driving connections between said shaft and cam, a pivotally mounted lever engaging said cam, a movable contact carried by said lever, a fixed contact adapted for engagement by said movable contact, said contacts being included in the circuit to said motor, and means including a speed governor mechanism for automatically adjusting the speed ratio between said shaft and cam in accordance with the speed of operation of said conveyor means, whereby the time required for one complete revolution of said cam substantially conforms to the length of time for the paper stock to move from said outlet to said caliper roll.

9. A paper making machine comprising a head box having an outlet, a gate movable for varying the effective area of said outlet, variable speed conveyor means positioned to receive stock from said outlet by gravity flow, a caliper roll bearing on the paper sheet on said conveyor where the said sheet has attained a self-sustaining body, a motor for moving said gate and under the influence of said caliper roll, a' cycle control unit comprising contacts in the circuit of said motor, means for causing the contacts to be engaged for a predetermined duration at regularly spaced intervals, speed responsive governor means connected to be driven in unison with said conveyor means and including a movable element, and means responsive to movement of said element for varying the duration of said in tervals, said last-named means including a lever and cam mechanism.

10. A paper making machine comprising a head box having an outlet, a gate movable for varying the effective area of said outlet, variable speed conveyor means positioned to receive stock from said outlet by gravity flow, a caliper roll bearing on the paper sheet on said conveyor where the said sheet has attained a self-sustaining body, a motor for moving said gate and under the influence of said caliper roll, a cycle control unit comprising contacts in the circuit of said motor, means for causing the contacts to be engaged for a predetermined duration at regularly spaced intervals, speed responsive governor means connected to be driven in unison with said conveyor means and including a movable element, and means including movement of said ele ment for varying the duration of said intervals, said last mentioned means accomplishing an ad justment of said intervals bearing a non-linear ratio to the speed variations of said conveyor means.

EMMONS F. LEWELLEN. DARCY E. LEWELLEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 17,767 Lewellen et al Aug. 12, 1930 93 ,217 Wood Sept. 7, 1909 1,119,472 Taussig Dec. 1, 1914 1,135,000 Donaldson Apr. 13, 1915 1,184,657 Paul May 23, 1916 1,643,716 Lewellen et al Sept. 27, 1927 1,768,088 Lewellen et al June 24, 1930 1,768,325 Lewellen et a1 June 24, 1930 1,773,832 Ware Aug. 26, 1930 2,166,137 Friedman et al July 18, 1939 2,176,164 Arthur Oct. 17, 1939