US3014527A

US3014527A - Stock distributor with adjustable inlet

Info

Publication number: US3014527A
Application number: US762877A
Authority: US
Inventors: Edward D Beachler
Original assignee: Beloit Iron Works Inc
Current assignee: Beloit Iron Works Inc
Priority date: 1958-09-23
Filing date: 1958-09-23
Publication date: 1961-12-26
Anticipated expiration: 1978-12-26
Also published as: GB924735A

Description

Dec. 26, 1961 D. BEACHLER STOCK DISTRIBUTOR WITH ADJUSTABLE INLET Filed Sept. 23, 1958 2 Sheets-Sheet 1 Edward D. Beach/er $1M 24-7%11 Dec. 26, 1961 E. D. BEACHLER 3,014,527

STOCK DISTRIBUTOR WITH ADJUSTABLE INLET Filed Sept. 23, 1958 2 Sheets-Sheet 2 hyEUfUP Unite States The instant invention relates to stock flow means for depositing stock on a forming wire, and more particularly, to a head box with an adjustable inlet.

Although the instant invention may have a number of uses in various fields, it is particularly useful in the art of paper making and will be described primarily in connection therewith. The present invention is useful in connection with the delivering of stock to a traveling forming wire, such as a Fourdrinier paper machine wire. Adjustable stock inlets have been known earlier in the prior art, but these devices in most instances left something to be desired in facility of adjustment, accuracy of adjustment, maintenance of parts, and/ or control of the positioning of the bottom wall leading edge and the top wall leading edge which define the slice jet.

The instant invention represents a solution to a number of problems encountered in the design of paper machine head boxes of substantial size adapted for operation at substantial speeds. In addition, the instant invention affords a number of advantages in adjustment of a head box. It provides direct and convenient means for matching the flow rates of stock to the paper machine speed, stock character, and basis weight of sheet to be formed on the machine, by varying a plurality of adjustable throat dimensions in an inlet to the head box to suit the various operating variables just mentioned. The instant device provides for a wide range of speeds and makes the head box useful for several different grades of stock,

In addition, certain other advantages of low cost are obtained by the elimination of one expensive fabrication. The instant invention provides the necessary characteristics of a paper machine head box in a relatively small size and retains easy access for cleaning, maintenance and the like.

One of the features of the instant invention is that it provides a head box having a substantially triangular longitudinal cross-section. This has been found to be advantageous in the distribution of forces exerted from within the head box which would otherwise tend to disturb uniformity of fiow at the slice jet.

It is, therefore, an important object of the instant invention to provide an improved head box.

It is another object of the instant invention to provide,

in a paper machine having a traveling forming wire, a

head box comprising first, second and third walls arranged to define a generally triangular cross-section for the head box, means defining an inlet at the apex between the first and second walls, the second and third walls defining at the apex therebetween a stock outlet onto the wire, and pivot means at the apex between the first and third walls swingably mounting said third wall for movement relative to said second wall.

A further object of the instant invention is to provide stock flow means for a paper machine having a traveling forming wire, comprising a bottom wall having a leading edge extending laterally of and in close proximity to the wire, a rear wall defining with the bottom wall an inlet for stock into said flow means, a top wall having a leading v edge extending laterally of and in close proximity to the wire, said top wall leading edge being spaced from said bottom wall leading edge to define a stock outlet from said stock flow means onto said wire, and means swingably mounting said top wall on said rear wall for moveice 2 ment of said top wall leading edge toward and away from said bottom wall leading edge. 7

Other and further objects, features and advantages of the present invention will become apparent to those skilled in the art from the following detailed disclosure thereof and the drawings attached hereto and made a part hereof.

On the drawings:

FIGURE 1 is a sectional elevational view of a head box embodying the instant invention; and

FIGURE 2 is a sectional elevational view of anothe head box embodying the instant invention, with parts shown diagrammatically.

As shown on the drawings: I

In FIGURE 1, the reference numeral 10 indicates generally a head box embodying the instant invention adapted to fiow stock onto a wire 11 trained around a breast roll 12 in theconventional manner. The head box 10 comprises a pair of side walls, namely, a rear side wall 13 and a generally parallel front side wall (not shown), between which are mounted a bottom wall 14 having a leading edge or apron 14a extending laterally and in close proximity to the wire 11, a rear wall 15 defining with the bottom wall 14 an inlet 16 for stock into the head box 10, anda top wall 17 having a leading edge or slice lip 17a extending laterally and in close proximity to the wire 11, the top Wall leading edge 17a being spaced from the bottom wall leading edge 14a to define a stock outlet or slice jet 18 therebetween for flowing stock onto the wire 11;

Expressed in other terms, the head box 10 comprises first 15, second 14 and third 17 walls arranged to define a generally triangular cross-section for the head box 10, and means 16 defining an inlet at the apex between'the first 15 and second 14 walls. The second 14 and third 17 Walls define at the apex therebetween a stock outlet 18- onto the wire. A pivot pin 19 at the apex between the first 15 and third 17 Walls swingably mounts the third wall 17 for movement relative to the second wall 15. Sealing means 20 (in the form of a sealing strip in a gland) associated with the pivot pin 19 is mounted on the topend 15a of the rear wall 15 and the sealing strip pin19, it will be seen that the top wall 17 has a rein forcing front strip 170, top strip 17d and side strips 17e, 17e (only one of which is shown). The pivot pin 19 is pivotally connected to the side strip 17a and another pivot pin 19 of similar structure is pivotally connected to the opposite side strip 17e (not shown). A bracket 21 is carried by a pivot pin 22 fixed to the rear wall 15, and the upper extremity of the bracket'21 carries the pivot pin 19 and thus holds the top wall 17 above the sealing strip 20, so that the sealing strip 20 will not be crushed, but it may carry out its function of effecting a seal. The pivot pin 19 is adjustably mounted by a set screw 23, with lock nut 24, carried by the upper extremity of the head box side wall 13 and connected to the bracket 21. The upper extremity of the side wall 13 is sloted at 13a to permit movement of the pivot 19 (at the extremity of the bracket 21) by adjustment of the set screw 23. In this way, the pivot pin 19 is movable toward and away from the slice jet 18, thus effecting a movement of the slice lip 17a toward and away from the wire 11 (and the apron 14a). Once the set screw 23 has been employed to adjust the exact position of the pivot pin 19, the bracket which may be any 21 may be secured to the side wall 13 in the slot 13a by means of a clamp 21a and threaded bolt 21b extending axially through the pivot pin 19. Other clamping means may be employed, but some device is preferred to lock the pivot pin 19 in position for a given set of operating conditions. The top wall 17 is then swingable about the pivot pin 19 and, for cleaning purposes as an example the top wall 17 may be moved to the position shown in dotted lines and designated 17'. The upward swinging of the forward end of the top wall 17 is accomplished by vertically adjustable means designated generally by the reference numeral 25. A pivot pin 26 is secured to the forward portion of the top wall 17 (on the top reinforcing strip 17b). An axially movable rod 27 is connected to the pivot pin 26 and vertical (or axial) adjustment thereof is accomplished by the adjusting means 25, of a number of known or conventional adjusting means. As here shown, the adjusting means 25 comprises a worm box 25a which comprises a worm mounted for rotation on a shaft 25b and engaging a worm gear within the box 25a. Suitable means including manual means may be employed to drive the shaft 25b, which rotates the worm (not shown) which in turn rotates a worm gear which is in the form of a sleeve with its interior threadedly engaging the upper extension of the rod 27 for relative axial movement. The worm and worm gear are well known structures which do not require further description herein, but it is suflicient to note that rotation of the shaft 25b results in axial movement of the rod 27. The vertically adjustable means 25 are suitably mounted on a pivot 250 to permit limited swinging thereof to compensate for the relatively slight adjustments of the pivot pin 19 made by the set screw 23.

As indicated also, minute adjustment of the slice lip 17a may be accomplished by the use of axially adjustable tie rods 28, a plurality of which are spaced across the 'full width of the machine and mounted on the front strip 170 of the top wall 17.

It will also be noted that the bottom wall 14 is provided with suitable reinforcement 14c which in turn is mounted on a fixed support 29.

Referring now to the details of the inlet 16, it will be seen that incoming stock fiows from a source of stock such as a fan pump (not shown) upwardly through a duct 30 and against a bafiie or flat Wall 31 in the overall conduit, whereat the stock undergoes a sharp right angle turn T-1 andspreads out laterally of the machine. The stockthen passes through a first throat S-1 and into a laterally extending header 32, from which the stock fiows upwardly through a plurality of short headers 33 (only one of which is shown) and against a second battle or roof portion 34, whereat the stock undergoes a second right angle turn T-2 and flows through a second throat -2. At the turn T-2 and through the throat 8-2 the stock spreads out uniformly throughout the width of the head box 10, then passes against still another baffle 35 (which forms a part of the bottom wall end 14b), whereat the stock undergoes still a third right angle turn T-3 and then passes through a third throat S3 and up into the head box proper. In the head box chamber a defined by the walls 14, and 17, the stock pond is subjected to gas'press'ure from a source of air under pressure entering at 36 and a stock level L-1 is maintained in the head box proper 10a just sufiicient to submerge recetifier rolls 37 and 38 by means of a gas liquid drain hole 39.

The drain hole 39 operates in conventional manner, so that a rise in the level L-1 may 'close over the drain hole 39 and thus cause a build up of pressure within the head box 10a which drives the level L4 down, or a lowering of the level II-1 completely exposes the drain hole 39 so that air under pressure escapes therefrom and permits the level L-1 to rise. In the instant'device, the rear wall 15 'is mounted,

onthe side walls

13, 13 for limited vertical and horizontal adjustment. The adjustment is effected by placing shims at the location 150 at the bottom extremity of the rear wall 15, or by relative vertical adjustment of the parts at this location. It will be noted that the end 14b of the bottom wall 14 has a generally L- shaped cross-section and the end 15b of the rear wall 15 has a generally L-shaped cross-section. These L- shaped cross-section members are nested, so as to define two throats 8-2 and S3. Vertical adjustment of the rear wall 15 opens and closes the throat 8-2 and horizontal adjustment of the rear wall 15 opens and closes the throat 8-3. As will be seen in theembodiment of FIGURE 2, however, actual adjusting devices are provided for accomplishing this adjustment in a superior manner.

Referering now to FIGURE 2, it will be seen that there is shown another head box embodying the instant invention. In the head box 100 there is provided a bottom wall 101 having a leading edge or apron 102 extending laterally and in close proximity to a forming wire 103 trained over a breast roll 104 in the conventional manner. The bottom wall 101 is a stationary wall and is provided with stationary vertical supports 105, 106 to retain the same in fixed position. The end oppo site the apron 102 of the bottom wall 101 has a generally L-shape in cross-section, with a portion 101a defining the foot of the L and another portion 101!) defining the stem of the L.

Parallel side walls 107, 107 (only one of which is shown) are, of course, mounted in sealing engagement with the bottom wall 101, and the side walls 107 are also stationary as in the case of the

side walls

13, 13 of the device 10. In the instant view, only a back side wall 107 is shown. The bottom wall 101 is primarily a horizontal wall; whereas a rear wall 108 is centrally a vertical wall,- and a top wall 109 extends at an angle, so as to form generally the hypotenuse of the right triangle defined by the three

walls

101, 108 and 109. This angular disposal of 'front wall 109 makes possible a very beneficial distribution of forces from within the head 'box 100. If the top wall 109 had a substantially vertical portion, such as its front strip piece 109a, the force of fiuid within the head box 100 would tend to bow the central portion of the strip 109a forwardly and thus disrupt the flow of stock out of the head box 100. The slice lip 10% which cooperates with the apron 102 to define the slice jet 110 does not bow outwardly in the middle, however, because it is supported by the angularly disposed wall 109 plus a vertically disposed front strip 109a (plus atop strip 10% which more or less completes a generally triangular configuration of the top wall 109 itself). This configuration is also shown in the case of the top wall '17 of the device '10 and it is important to note that the positioning of the inside skin of the top wall 109 permits the most favorable distribution of forces from within the head box 100 without distortion of the slice 'lip 10%.

As will be seen, the top wall 109 is swingably mounted on a pivot pin 111that is connected through a bracket 1'12 and a pivot pin '113 to the rear Wall 108. Vertically adjustable means indicated generally at 114 are connected 'to a pivot pin 115 at the forward portion of the top wall 109. The vertically adjustable means 114 again comprise a worm and worm gear box such as the box 25 described in connection with FIGURE 1, but other adjustable means may be used and the worm box 114 is conventional, so further description thereof is not necessary' It will be noted that the 'worm gear box 114 is mounted to accommodate limited tilting, as in the case of the worm gearbox 25, because 'the pivot pin 111 is adjustably movable in a generally horizontal direction (and toward and away'from the slice jet 110). The principal adjustment-of the slice lip 10% in a vertical direction is accomplished by the vertically adjustable means 114. It will be appreciated that vertically

adjustable means

114, 114 are mounted on opposite sides of the also be noted that sealing means 116 in the form of a sealing strip carried in a gland extending the full width of the rear wall 108 are mounted on the rear wall. An opposite face portion 117 is mounted at the upper extremity of the top wall 109 for cooperation with the sealing strip 116 during relative movement of the top 109 and rear 108 walls.

The pivot pin 111 is mounted on a horizontally movable carrier 120, here shown diagrammatically. The carrier is movable in the direction indicated by the twoheaded arrow by means of another worm gear box 121 mounted on a fixed support (and also shown diagrammatically). The carriage 120 moves on a fixed track 122 carried on an extremity 107a of the side wall 107.

As indicated, the rear wall 108 is connected to the bracket 112 by a pivot pin 113, and vertically adjustable means 123 (shown diagrammatically again as a worm gear box) are carried by the carriage 120 and connect to the pivot pin 113. The bracket 112, plus the connection with the vertically adjustable means 123, both at the pivot pin 113, makes possible generally horizontal movement of the rear wall 108, while the vertically adjustable means 123 makes possible the vertical movement of the rear wall 108. This adjustment arrangement is particularly convenient for adjusting flow or" stock through the inlet 124 for the head box 100.

As shown, the inlet 124 is defined between the fixed bottom wall 101 and the relatively movable rear wall 108. The rear wall 108 is provided with a back skin 108a and reinforcing members and with a generally L-shaped lower portion 108a having a bottom strip 108d that forms the foot of the L and a vertical strip 108:? that forms the stem of the L. Between the foot strips 101a and 108d there is a throat S-4 and between the stem strips 1011) and 108e there is another throat 8-5. The horizontal movement of the end wall 108 effects opening and closing the throat S-5 and vertical movement of the end wall 108 effects opening and closing of the throat S4, and in this way two conveniently controlled arrangements are permitted for controlling the flow of stock into the head box 100. Although the means for vertical and horizontal adjustment of the end wall 108 are particularly convenient for use, it is generally preferable to employ a stop or holding means to retain the wall 108 in position once adjustment has been made, and this is shown essentially diagrammatically at 130'. The holding means 130 comprises an elongated slot 130a in the extension 107a of the side wall 107 through which a bolt 13012 carried on an arm 130a attached to the rear wall 108 passes to engage a circular clamp 130d, so that the bolt 13017 and clamp 130d may be secured in clamping arrangement after adjustment has been made, but during adjustment the bolt 1301) may move freely in the slot 130d.

Referring to certain details of the stock inlet, it will be noted that the stock flows initially from a fan pump (not shown) through a vertical header 131 then against a baffle 132 at which the stock undergoes a first right angle turn T- 4 and then passes through a first throat S-6 and into a cross header 133, from the cross header 133, the stock flows upwardly through a plurality of short conduits 134 (only one of which is shown). The stock flows from the conduits 134 against the foot strip 108d of the rear wall 108, whereat the stock undergoes a second right angle turn T-5 and then passes through a second throat S-4, from there against the stem strip 101b of the bottom wall 101 through still another right hand turn T+6 and then through the throat 85. As the wall 108 is moved either vertically or horizontally, the relative positions of the foot strips 108d and 101a will vary. In order to insure a rear seal at the turn T-S, movable sealing means 136 are provided in the form of a frame covered with rubber sealing material which engages the extreme edge of the bottom wall 101 (at the foot portion 101a) and which engages the bottom portion of the rear wall 108 at the same time. The sealing strip 136 is urged upwardly and into sealing position by an air spring 137 acting against an arm 138 pivoted at 139. As in the previously described head box 10, the stock flows upwardly from the inlet 124 into the head box proper, past rectifier rolls 140 and 141 and out the slice jet 110. Air under pressure is introduced into the head box at 142 and a fluid drain aperture 143 functioning in the same manner as the drain aperture 39 of the head box 10 maintains the stock level L-2 just sufiicient to submerge the rectifier rolls 140, 141.

It will be understood that modifications and variations may be effected without departing from the spirit and scope of the novel concepts of the present invention.

I claim as my invention:

1. In a paper machine having a traveling forming wire, a head box comprising first, second and third generally rigid walls arranged to define a generally triangular crosssection for the head box, means defining an inlet at the apex between the first and second walls, the second and third walls defining at the apex therebetween a stock outlet onto the wire, and pivot means at the apex between the first and third walls swingably mounting said third wall for movement relative to said second wall.

2. In a paper machine having a traveling forming wire, a head box comprising first, second and third generally rigid walls arranged to define a generally triangular crosssection for the head box, one end of the first wall cooperating with one end of the second wall to define an inlet, the other end of the second wall cooperating with one end of the third wall to define an outlet for flowing stock onto the wire, and pivot means carried by the other end of the first wall swingably mounting the third wall.

3. In a paper machine having a traveling forming wire, a head box comprising first, second and third generally rigid Walls arranged to define a generally triangular crosssection for the head box, one end of the first wall cooperating with one end of the second Wall to define an inlet, the other end of the second wall cooperating with one end of the third wall to define an outlet for flowing stock onto the wire, pivot means connected to the other end of the third wall and carried by the other end of the first wall for swinging movement of the third wall, and sealing means associated with the pivot means for maintaining a fluid seal between the first and third Walls during relative movement thereof.

4. In a paper machine having a traveling forming wire, stock flow means of generally triangular cross-section comprising a bottom wall having a leading edge extending laterally of and in close proximity to the wire, a rear wall defining with the bottom wall an inlet for stock into said flow means, a top generally rigid wall having a leading edge extending laterally of and in close promixity to the wire, said top wall leading edge being spaced from said bottom wall leading edge to define a stock outlet from said stock flow means onto said wire, and means swingably mounting said top wall on said rear wall for movement of said top wall leading edge toward and away from said bottom wall leading edge.

5. In a paper machine having a traveling forming wire, stock flow means of generally triangular cross-section comprising a bottom wall having a leading edge extending laterally of and in close proximity to the Wire, a rear wall defining with the bottom wall an inlet for stock into said flow means, a top generally rigid wall having a lead ing edge extending laterally of and in close proximity to the wire, said top wall leading edge being spaced from said bottom wall leading edge to define a stock outlet from said stock flow means onto said wire, means swingably mounting said top wall on said rear wall for movement of said top wall leading edge toward and away from said bottom wall leading edge, and vertically adjustable means pivotally connected to a forward portion of said top wall to effect swinging movement thereof.

6. In a paper machine having a traveling forming wire,

stock flow means of generally triangular cross-section wall and defining therewith an inlet for stock into said fiow means, adjustable means connected to said rear wall from movement of the rear wall face portion toward and away from the bottom wall at said inlet, a top generally rigid wallliaving a leading edge extending laterally of and in close proximity to the wire, said top wall leading edge being spaced form said bottom wall leading edge to define a stock outlet from said stock fiow means onto said wire, and means swingably mounting said top Wall on said rear Wall for movement of said top wall leading edge toward and away from said bottom wall leading edge.

7. In a paper machine having a traveling forming wire, stock flow means of generally triangular cross-section comprising a bottom wall having a leading edge extending laterally of and in close proximity to the wire, a rear wall having a face portion closely spaced from the bottom wall and defining therewith an inlet for stock into said flow means, adjustable means connected to said rear wall from movement of the rear wall face portion toward and away from the bottom wall at said inlet, a top generally rigid wall having a leading edge extending laterally of and in close proximity to the wire, said top wall leading edge being spaced form said bottom wall'leading edge'to define a stock outlet from said stock flow means onto said wire, and bracket means pivotally connected to said rear wall and said top wall swingably mounting said top wall on said rear wall for movement of said top wall leading edge toward and away from said bottom wall leading edge.

8. In a paper machine having a traveling forming wire, a head box of generally triangular cross-section comprising a bottom wall having a leading edge extending laterally of and in close proximity to the wire, a rear wall having a face portion closely spaced from the bottom wall and defining therewith an inlet for stock into said fiow means, adjustable means connected to said rear wall from movement of the rear wall face portion toward and away from the bottom wall at said inlet, a top generally rigid wall having a leading edge extending laterally of and in close proximity to the wire, said top wall leading edge being spaced from said bottom wall leading edge to define a stock outlet from said stock flow means onto said wire, bracket means pivotally connected to said rear wall and said top wall swingably mounting said'top wall on said rear wall for movement of said top wall leading edge toward and away from said bottom wa l leading edge, and vertically adjustable means pivotally connected to aforward portion of said top wall to effect swinging movement thereof.

9. In a paper machine having a traveling forming wire, a head box-of generally triangular cross-section comprising a bottom wall having a leading edge extending laterally of and in 'close proximity to the wire, a rear wall having a face portion closely spaced from the bottom wall and defining therewith an inlet for stock into said flow means, adjustable means connected to said rear wall from movement of the rear wall face portion toward and away from the bottom wall at said inlet, a top generally rigid wall having a leading edge extending laterally of and in close proximity to the wire, said top wall leading edge being spaced from said bottom wall leading edge to define a stock outlet from said stock flow means onto said wire, bracket means interconnecting a pivot on said rear wall and a pivot on said top wall swingably'mounting said top wall on said rear wall for movement of said top wall leading edge toward and away from said bottom wall leading edge and adjustable means mounting said pivot on said top wall.

10. In a paper machine having a traveling forming wire, a head box of generally triangular cross-section comprising a bottom wall having a leading edge extending laterally of and in close proximity to the wire, a rear wall defining with the-bottom wall an inlet for stock into said flow means, a top generally rigid wall having a leading edge extending laterally of and in close proximity to the wire, said top wall leading edge being spaced from said bottom wall leading edge to define a stock outlet from said stock flow means onto said wire, first pivot means adjacent said rear wall swingably mounting said top wall for movement of said top wall leading edge toward and away'from said bottom wall leading edge, and adjustable means carrying said first pivot means for movement generally toward and away from said bottom wall leading edge.

11. In a paper machine having a traveling forming wire, a head box of generally triangular cross-section comprising a bottom wall having a leading edge extending laterally of and in close proximity to the wire, a rear wall having a face portion closely spaced from the bottom wall and defining therewith an inlet for stock into said flow means, adjustable means connected to said rear wall from movement of'the rear wall'face portion toward and away from the bottom wall at said inlet, a top generally rigid wall having a leading edge extending laterally of and'in close proximity to the wire, said top wall leading edge being spaced from said bottom wall leading edge to define a stock outlet from said stock flow means onto said wire, first pivot means adjacent said rear wall swingably mounting said top wall for movement of said top wall leading edge toward and away from said bottom wall leading edge, and carriage means carrying said first pivot means and said adjustable means for movement generally toward and away 'from said bottom wall leading edge.

12. In a paper machine having a traveling forming wire, a head box of generally triangular cross-section comprising a bottom wall having a leading edge extending laterally of andin close proximity to the wire, a rear wall having a face portion closely spaced from the bottom wall and defining therewith an inlet for stock into said fiow means, adjustable means connected to said rear wall from movement of the rear wall face portion toward and away from the bottom wall at said inlet, a top generally rigid wall having a leading edge extending laterally of and in close proximity to the wire, said top wall leading edge being spaced from said bottom wall leading edge to define a stock outlet from said stoclcfiow means onto said wire, first pivot means adjacent said rear wall swingably mounting said top wall for movement of said top wall leading edge toward and away from said bottom wall leading edge, second pivot means on said rear wall, bracket means interconnecting said first and second pivot means, and carriage means carrying said first pivot means and saidadjustable means for movement generally toward and away from said bottom wall leading edge.

13. In a paper machine having a traveling forming wire, a head box comprising first, second and third generally rigid walls arranged to define a generally triangular cross-section for the head box, one end of said second wall having an L-shape in cross-section and one end of said first wall also having an L-shape in cross-section, said L-shapes being in nested relation to define a first stock inlet'throat between the feet of the Us and a second stock inlet throat between the stems of the Us, adjustable means mounting the first wall for selective opening and closing of said first throat, the other end of the second wall cooperating with one end of the third wall to define an outlet for allowing stock onto the wire, and pivot means carried by the other end of the first wall swingably mounting the third wall.

14. In a paper machine having a traveling forming wire, a head box comprising first, second and third generally rigid walls arranged to define a generally triangular cross-section for the head'box, one end of said second wall'having an L-shape in cross-section and one end of :said first wall also having an L-shape in cross-section,

said L-shapes being in nested relation to define a first stock inlet throat between the feet of the Us and a second stock inlet throat between the stems of the Ls,adjustable means mounting thefirst wall for selective opening and closing of said second throat, the other end of the second wall cooperating with one end of the third wall to define an outlet for flowing stock onto the wire, and

pivot means carried by the other end of the first wall swingably mounting the third wall.

15. In a paper machine haying a traveling forming wire, a head box comprising first, second and third generally rigid walls arranged to define a generally triangular cross-section for the head box, one end of said second wall having an L-shape in cross-section and one end of said first wall also having an L-shape in cross-section, said L-shapes being in nested relation to define a first stock inlet throat between the feet of the Us and a second stock inlet throat between the stems of the Ls, adjustable means mounting the first wall for selective opening and closing of said first throat and said second throat, the other end of the second wall cooperating with one end of the second wall to define an inlet, the other end of the second wall cooperating with one end of the third wall to define an outlet for flowing stock onto the wire, and pivot means carried by the other end of the first wall swingably mounting the third wall.

16. In a paper machine having a traveling forming 10 wire, a head box comprising first, second and third generally rigid walls arranged to define a generally triangular cross-section for the head box, means defining an inlet at the apex between the first and second walls, the second and third walls defining at the apex therebetween a stock .outlet onto the wire, pivot means at' the apex between the first and third walls swingably mounting said third wall for movement relative to said second wall, and positioning means mounting said pivot means for movement generally in the plane of said third wall.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Mardon: Paper Trade Journal, June 25, 1956, pp. 28-29.