US2585049A

US2585049A - Pulp molding die

Info

Publication number: US2585049A
Application number: US94180A
Authority: US
Inventors: Ernest L Shepard
Original assignee: CANAL NAT BANK; WILLIAM B NULTY
Current assignee: CANAL NAT BANK; CANAL NATIONAL BANK; WILLIAM B NULTY
Priority date: 1949-05-19
Filing date: 1949-05-19
Publication date: 1952-02-12
Anticipated expiration: 1969-02-12

Description

3 Sheets-Sheet l E. L. SHEPARD PULP MOLDING DIE Feb. 12, 1952 Filed May 19, 1949 INVENTOR. Erf; esl L. 'e/oard.

V El

I Affe Doo Feb. 12, 1952 E. L. SHEPARD PULP MOLDING DIE 3 Sheets-Sheet 2 Filed May 19, 1949 INVENTOR. Ernest L. Sefara' @Wu-@M Feb- 12, 1952 E. 1 SHEPARD 2,585,049

PULP MOLDING DIE Filed May 19, 1949 3 Sheets-Sheet 5 Fly. 7

INVENTOR. Ern es t `L. She/Gard.

NM @1 @L Hrro HNEY disposed inwardly of the border sub-areas.

Patented Feb. l2, 1952 PULP MOLDING VDIE Ernest L. Shepard, Fairfield, Maine, assignor, by mesne assignments, to The Canal National Bank of Portland and William B. Nulty, Portland, Maine, astrustes Application May 19, 1949,.Serial'Noo94,180

7 Claims.

1 This invention relates to an open-face pulp molding die-unit for the suction formation, from a pulp-water` slurry, of molded pulp articles such as egg flats or analogous articles.

This application is a continuation-in-part of my application S. N. 402,478 filed July l5, 1941, now abandoned, andmy application S. N. 571,753 filed January 8, 1945, also abandoned.

In the present invention I have provided a pulp molding die-unit embodying a unitary die-plate, the molding area of which is deiined by a diering. A plurality of grooves which open out into the molding area divide it into a plurality` of border sub-areas located adjacent to the die-ring and, in addition, a plurality of inner sub-areas Each sub-area, or minor molding area, has a conformation corresponding to the section of the article to be molded thereon. A plurality of wire mesh screen hoods each snugly engages the die-plate and a sub-area thereof. Each hood associated with the inner sub-areas has marginal flanges which extend into the contiguous grooves defining the rperimeter of the inner sub-area, and each hood is frictio'nally locked Within its respective perimetric groove. Each hood of the border subareas has marginal flanges, including flanges which are directly adjacent to the die-ring. Such adjacent flanges are frictionally locked to the die-plate, and the non-adjacent flanges of such hooks extend into contiguous grooves and are frictionally locked therein. By this construction at least those hoods which are associated with the inner sub-areas may be initially positioned or replaced from the face side of the unitary die-plate, and are held in place independently of the die-ring.

According to one specific embodiment of the invention, the hood flanges directly adjacent to the die-ring extend between the die-ring and the die-plate, and are frictionally locked therebetween. With such construction, each of the hoods associated with the inner sub-areas `may be initially positioned orreplaced from the face side of the unitary die-plate, and are held in place independently of the die-ring.

According to another embodiment of the invention, the die-plate is provided with a perimetric groove at the margin of the molding area just inside the inner wall of the die-ring, and the hood flanges directly adjacent to the diering extend downwardly into said perimetric groove and are frictionally locked therein. With this construction, all 'of the individual hoods overV the entire molding area of' the die-plate-may 'NLT' oF Fics be initially positioned orrlepledr from the 'f'ce side of the unitary die-plate, and are held in place independently of the die-ring.

In the drawings:

Figure 1 is a plan View of an open-facepulp molding die-unit showing grooves extendingsubstantially to the die ring, and showing certain of the wire mesh screen hoods in position;

2 is a vertical section on line 2'-2 of Fig. 1

Fig. 3 is a fragmentary vertical sectiontaken on line 3--3 of Fig. 1 showing certain screen hoods in position with depending. flanges disposed in grooves in the die-plate and with anoutwardly extending flangefrictionally held between the die-plate and the die-ring;

Fig. 4 is a fragmentary vertical section taken on line l-ll of Fig. 1;

Fig. 5 is a fragmentary .plan view of a die-unit showing a modified.r form of groove construction wherein the grooves extend substantially to the die-ring but wherein portions of the grooves eX- tend under the die-ring;

Fig'is a fragmentary vertical section taken @n line 6 6 of Fig. 5'showing screen hoods with `depending and outwardly extending flanges;

Fig. 7 is a fragmentary plan View of a die unit showing another form of construction wherein ygrooves in the dieplate extend substantially to the die ring and intersect a perimetric groove zdisposed just inside the inner wallof the die-ring;

Fig. 8V is a fragmentary vertical sectiononline 8-8;0f,Fig. 7;

Fig; 9 is a fragmentarysectional view showing a modiiication of the invention wherein` -the perimetri@ groove is formed in part. by the inner'wall ofthe die-ring;

Fig. 10 is a perspective view of a ycontcured screen hood with a plurality of depending. flanges and with` anoutwardly 'extending ange;

Fig. 1-1'is` a perspective' viewof acontoured screen hood wherein all of the ilanges: extend downwardly;

vscreen hoods frictionally lc'clfe'dlin` a groove. by

means of a locking strip; and,

Fig. 14 is a.. fragmentary vertical.'.section'rsimilar to Fig. 13 `showing depending kanges of screen-hoods frictionally heldA in position without additional locking means.

In Figs. 1 to 4 inclusive I have disclosed an embodiment of my invention in which the intersecting grooves extend substantially to the die-ring and wherein the screen hood flanges adjacent to the die-ring extend thereunder and are frictionally held between the die-ring and the dieplate. In this embodiment there is shown a one piece or lunitary die-plate 2 (Fig. 2) to which is secured by suitable means such as screws 4, a diering 6. The inner wall 8 of the die-ring denes the molding area I and the edge of the article to be molded thereon. The molding area I0 is substantially parallelogrammatic, and specifically rectangular, in shape. Surrounding the molding area I0 on the die-plate 2 is the periperal portion I2 and to this peripheral portion I2 the diering 6 is shown as secured. Over its entire molding area I0 the die-plate 2 is provided with drainage openings I4 leading therethrough from said molding area I8. These drainage openings I4 are shown in Fig. 2, are shown in part in Fig. 1, and for simplification are omitted from Figs. 3 and 4.

The unitary die-plate 2 is shown as provided with a set of grooves I6 which as shown do not extend all the way through the thickness thereof but which do open out through the molding area II) of the die-plate. These grooves are shown as spaced apart and substantially parallel with one another and with one pair of inner walls 8a (Fig. 1) of the die-ring 6. The grooves I6 are shown as extending substantially to the inner walls 8b of the die-ring 6.

The die-plate 2 is further provided with a simi- `lar and second set of grooves I8 opening out through the molding area I0 of the die-plate. The grooves I8 are spaced apart and are substantially parallel with each other and with the inner walls 8b of the die-ring 6. The grooves I8 of the second set extend substantially to the inner walls 8a of the die-ring. The grooves. I8 cross the grooves I6 of the first set at substantially right angles to form a plurality of minor molding areas or sub-areas. Thus there are formed the

minor molding areas

20, 22 and 24.

The minor molding areas or border sub-areas (Fig. 1) are contiguous to the inner wall 8 of the die-ring 6 on two sides and the minor molding areas 22 are contiguous to the die-ring wall 8 on one side. Together, the

minor molding areas

20 and 22 constitute a plurality of border subareas located contiguous to the die-ring 6, and each of said

border molding areas

20 and 22 has at least one side directly adjacent to the inner wall of the die-ring 6. The minor molding areas 24 constitute a plurality of inner sub-areas disposed inwardly of the border sub-areas and each of the inner sub-areas 24 is bounded on all sides by contiguous portions of grooves I6 and I8.

Each of the

minor molding areas

20, 22 and 24 has a conformation corresponding to the section of the article to be molded thereon and to this end may be provided with individual forming projections 26 (Fig. 2) and pocket forming cavities 28.

There is provided a ne wire mesh hood individual to each

sub-molding area

20, 22 and 24 and providing the forming surface thereof. Thus a hood 30 is provided for each molding area 20. a hood 32 is provided for each molding area 22 and a hood 34 is provided for each molding area 24. The total of these

hoods

30, 32 and 34 constitute a screen snugly engaging the die-plate 2 over the molding area II)V thereof and each hood consti- `tutes the foraminous cover for a minor molding area. Each

hood

30, 32 and 34 is parallelogrammatic, and specifically rectangular, in shape.

The hoods 30 have the outwardly extending ilanges or marginal portions 36 which extend beneath the contiguous portion of the die-ring 6 and which are shown as frictionally held between the die-ring 6 and the peripheral area I2 of the die-plate 2 by being removably clamped between said die-ring and said peripheral area of the die-plate. The hood 30 has additional depending ilanges 38 which extend into grooves I6 and I8 and are frictionally retained therein.

Each of the hoods 32 (Figs. 1, 2 and 10) has an outwardly extending flange or marginal portion 40 extending beneath the contiguous portion of the die-ring 6 and arranged to be removably clamped between said die-ring and the peripheral area I2 of the die-plate, whereby said ange 40 may be frctionally held therebetween. The hood 32 has additional and depending marginal anges 42 which extend into and are frictionally held Within, the continguous portions of the grooves I6 and I8 which dene the border sub-areas with which the hood is associated.

The hoods 34 (Figs. 1, 3 and 11) associated with the inner sub-areas I4 have depending flanges 44 at their marginal edges which extend into grooves I6 and I8 and are retained solely by friction in those portions of the grooves I6 and I8 which define the sub-area with which the hood is associated. In other words, each hood 34 is frictionally locked within its respective minor perimetric groove constituted by the contiguous portions of the grooves I6 and I8.

While the depending flanges of the

hoods

30, 32 and 34 may be frictionally locked within the contiguous portions of the grooves I6 and I8 in any suitable manner, it is convenient and preferred to accomplish this frictional retention by means of locking strips 46 as indicated in Figs. 2, 3 and 4.

From the construction herein above described, it will be noted that any of the hoods 34 associated with the inner sub-areas 24 may be removed from the front of the die and replacement hoods substituted, without disturbing the diering or removing any of the other hoods associated with either the inner areas 24 or the

border sub-areas

20 or 22.

The unitary die-plate 2 may be associated with a die carrier 4I (Fig. 2) of a pulp moldingr machine by suitable fastening means such as screws 43 to provide the drainage chamber 45 which may be connected by a pipe or conduit 4l with suitable means for producing suction during the forming operation, and alternatively pressure, if desired, in assisting to displace a formed article from the molding area.

In Figs. 5 and 6 I have illustrated a modication of the die construction shown in Figs. l to 4 inclusive, wherein the grooves extend substantially to the die-ring but wherein portions of such grooves extend under the die-ring. The unitary die-plate 48 has a peripheral area 50 to which is attached the die-ring 52 by suitable means such as the screws 54. The inner wall 56 of the die-ring 54 defines the molding area and the edge of the article to be molded. The die-plate' 48 is provided with drainage openings 58 leading therethrough from the molding area. The molding area is divided into minor molding areas 60 by a set of grooves 62 which are spaced parallel to each other and to the inner walls 56a of the die-ring, and by the grooves 64 which are also spaced parallel to each other and to the inner wall 58a of the diering and which, as shown, intersect the grooves 62' 'substantially at, right angles. The grooves '62 and'f'l 'extendjsubstantially to the inner wall 56 ofi'the die-ring 52 and portionsV 62a. and 64a extend under the die-ring. It will be understood ofcourse that the portions 62a--and- `lisa dov not extend as far as the outer Wall of' the peripheral portion 50, in order to prevent lundesired entry of pulp when the die unit is submerged in a pulp slurry. In Fig. 6 a hood 66 is shown. similar to the hood 32 in Fig. 10, and having depending anges 68 extending into grooves 62', depending flange 10 extending into grooves 6.4, and having outwardly extending iijange 12 frictionally held between vthe 'die-ring 5:11 and the peripheral portion 59 of the die- `vIn Figs. 7 and 8v I 'have illustrateda highly advantageous embodiment of my invention wherein all of the individual hoods lcovering minor molding areas, including those adjacent to the dire-ring, `may be initially positioned or replaced from the face side of the unitary dieplate and wherein every such hood is held in place independently of the die-ring. Thus, in

7 and 8 there is shown a unitary die-plate 14 having a peripheral portion 16 and a die ring 18 Vsecured by suitable fastening means,

'such as the screws 80, to said peripheral portion 13. The inner wall 82 of the die-ring 18 denes the substantially parallelogrammatic, specifically rectangular, molding varea and the edge of. the article `to be molded. The die-plate 14 is provided with drainage openings 84 leading, therethrough from the molding area. The die-plate is additionally provided with a peri'- metric groove 86 within the molding area and opening out through the molding area of the dieplate 14 just inside the inner wall 82 oi the die-ring. The die-plate 14 is further provided with aset of grooves 88. Grooves 88 are spaced apart and substantially parallel with one another and with the inner walls 82a of the diering. The grooves 88 extend substantially to the inner Walls 82h 'of the die-ring and intersect the perimetric groove 86. In a second set, grooves 90 are spaced apart, substantially parallel with each other and with the inner walls B2b of the die-ring. The grooves 98 extend substantially to the inner walls 82a of the diering and intersect the perimetric groove 8B. The intersecting grooves 88 and 90 all open out through the molding area of the die-platev M. The grooves 38areshown as crossing the grooves 9i). Iat substantially right angles thereto, and vwith the perixnetric groove 88, form minor molding areas 92 each of parallelogrammatic, Vspecically rectangular, shape and each definedl by a minor perimetric groove. Each minor perimetric groove is constituted-by contiguous portions o`f the grooves 88 and 9U, or 86, 88'and '99, 'as the case may be.

Vfo'raminous cover for a minor molding'area '92. vEach hood 6| is shown as being parallelogramvmatic, specifically rectangular, iii-'shapeand'has 6. marginal flanges 63 extending Vinto the con-f tiguous grooves defining the perimeter-lof each minor molding area. Each hood -6I may be f-rictionally locked Within its respective minor perimetric groove in any suitable manner. Conveniently and preferably this may be accomplished by means of locking keys or strips M65A.v

From the construction-shown inl Figs. 7 land 8 and' described hereinabove it will beV seen that each of the individual hoods 6l lmay 'be 'ini'- tia-lly positioned or replaced from the aceside of the unitary die-plate 14 Without disturbing the die-ring 18 or removing any of' the other hoods 6|. Furthermore each hood 6I is held in place independently of the die-ring 18.

A modiiicationof the perimetrio groove construction vdisclosed in Figs. 7 and 8 is -shownfin Fig. 9. Thus, in Fig. 9 there is shown a dieplate 61 to which is secured a die-ring V69 by `suitable fastening means such as the screws-11|. A wire mesh screen hood 1-3 has depending ange 15 which extends into the perimetric groove 11. The inner wall of the perimetric groove 11 is dened by the die-plate 61. and the outer Wall of the perimetric groove 11- is defined by the inner wall 19 of the die-ring 1|. The depending iiange 15 is frictionally locked within the perimetric groove 11 by suitable means such as the locking key or strip 8|.

In Fig. 12 I have illustrated in detail a` preierred manner of frictionally locking depending flanges of hoods in grooves. Thus in Fig. 12 lthere is shown a die-plateY 83A having drainage openings 85 and grooves V81. Hoods 89 which cover minor holding areas have depending anges 9i extending into the grooves 81, and stopping short of the bottoms of said grooves. Keys 93 are disposed between depending flanges 9| and serve frictionally'to lock said depending anges in position. The keys 93 are as shown as extending into the bottoms of the grooves 81. In Fig. 13 there is shown, in still further enlargement, a fragment oi the die-plate 81 of Fig. 12, depending flanges 9| of hoods 89, and locking key 93.

In Fig. 14 is illustrated an alternative manner of irictionally locking flanges within a groove,

wherein the depending flanges 95 oi hoods 91 extend into the slot 99 of die Il, and arefrictionally locked therein without the aid of addi'- vtional" locking meansl v It'will be understood that variousv alternative forms of construction may be employed without departing from the spirit and scope of this in'- vention. Thus the die-ring may be secured to the die-plate in any suitable manner, other than'being secured to a peripheral portion of the die-plate as illustrated in the drawings.

It Will be further understood that a single hood may be arranged to cover oneminor mold'- ing area as illustrated herein or maybe arranged to cover a plurality of minor molding areas.

It will iurtherbe noted that the molding area defined by the die-ring need not be rectangular or parallelogrammatic as illustrated herein, but may be of any suitable closed shape, curved or polygonal, regular or irregular. Sets of grooves may be parallel vas shown, or non-parallel, and the grooves may be'straight, as shown, oroi curved or irregular character. Furthermore the minor molding areas may be of any'suitable shape, regular Yor irregular.

It will further be understood that the conformationv of the moldingarea may be suitedtothe purpose atu hand and: may' consist of y"a duplica-- tion of like confrmations or may consist of .a variety of differing conformations.

Various other' modications in construction and arrangement may obviously be resorted towithout departing from the spirit and scope oi the invention as deiined by the appended claims.

I claim:

1. In an open face pulp moldingy die-unit for the suction formation of molded pulp egg ats or analogous articles, in combination, a unitary dieplate having a molding area, a die-ring defining the molding area and the edge of the article to be molded, said die-plate being provided with drainage openings leading therethrough from the molding area, said die-plate being further provided with a plurality of retaining grooves open- ,ing out into the molding area, extending substantially to the inner wall of said die-ring, and dividing the molding area into a plurality of border sub-areas locatedadjacent to the die-ring, and, in addition, a plurality of inner sub-areas disposed inwardly of the border sub-areas, each sub-area having a conformation corresponding to Ithe section of the article to be molded thereon, a plurality of wire mesh screen hoods each snugly engaging the die-plate over a sub-area thereof, each hood associated with the inner sub-areas having marginal flanges extending into the contiguous grooves defining the perimeter' of the inner sub-area and being rictionally locked within its respective perimetric groove, each hood of the border sub-areas having marginal anges including ilanges which are directly adjacent to the die-ring, such adjacent flanges being frictionally locked to the die-plate, the non-adjacent iianges of such hoods extending into contiguous grooves and being frictionally locked therein, whereby at least those hoods which are associated with the inner sub-areas may be initially positioned or replaced from the face side of the unitary dieplate, and are held in place independently of the die-ring.

2. In an open-face pulp molding die-unit for the suction formation of molded pulp egg flats or analogous articles, in combination, a unitary dieplate having a substantially parallelogrammatic molding area, a die-ring defining the molding area and the edge of the article to be molded, said vdie-plate being provided with drainage openings leading therethrough from the molding area, said die-plate being further provided with two sets of intersecting grooves opening out into the molding area and extending substantially to the inner wall of said die-ring, the grooves of one set being spaced apart and substantially parallel with one another, the grooves of the other set being spaced apart, substantially parallel with one another, and crossing the grooves of the first set, said grooves dividing the molding area into a plurality of substantially parallelogrammatic border subareas located adjacent to the die-ring, and, in addition, a plurality of substantially parallelogrammatic inner sub-areas disposed inwardly of the border sub-areas, each sub-area having a conformation corresponding to the section of the article to be molded thereon, a plurality of wire mesh screen hoods each parallelogrammatic in shape and snugly engaging the die-plate over a sub-area thereof, each hood associated with the inner sub-areas having marginal flanges extending into the contiguous grooves deiining the perimeter of the inner sub-area and being frictionally locked within its respective perimetric groove, each hood of the border sub-areas having marginal flanges including flanges which are di- -rectly adjacent to the'die-ring, said adjacent flanges being frictionally locked to the die-plate. the non-adjacent anges of such hoods extending into contiguous grooves and being frictionally locked therein, whereby at least those hoods which, are associated with the inner sub-areas may be initially positioned or replaced from the face side of the unitary die-plate, and are held in place independently of the die-ring.

3. In an open-face pulp molding die-unit for the suction formation of molded pulp egg flats or analogous articles, in combination, a unitary dieplate having a molding area, a die-ring secured to the die-plate and defining the molding area and the edge of the article to be molded, said dieplate being provided with drainage openings leading therethrough from the molding area, said dieplate being further provided with a plurality of retaining grooves opening out into the molding area, extending substantially to the inner wall of said die-ring, and dividing the molding area into a plurality of border sub-areas located adjacent to the die-ring, and in addition, a plurality of inner sub-areas disposed inwardly of the border sub-areas, each sub-area having a conformation corresponding to the sections of the article to be molded thereon, a plurality of wire mesh screen hoods each snugly engaging the die-plate over a sub-area thereof, each hood associated with the inner sub-areas having marginal ianges extending into the contiguous grooves dening the perimeter of the inner sub-area and being frictionally locked within its respective perimetric grooveI each hood of the border sub-areas having marginal anges including anges which are directly adjacent to the die-ring, such adjacent flanges extending between the die-ring and the die-plate and being frictionally locked therebetween, the non-adjacent flanges of such hoods extending into contiguous grooves and being frictionally locked therein, whereby each hood associated with the inner sub-areas may be initially positioned or replaced from the face side of the unitary dieplate, and are held in place independently of the die-ring.

4. An open-faced die assembly for the production from a pulp-water slurry, by suction molding, of egg flats or analogous articles comprising a unitary die plate having a molding area and a peripheral area surrounding the molding area, a die ring superimposed upon the peripheral area, means for securing the die ring to the peripheral area, a die plate carrier, the die platebeing provided with drainage openings therethrough leading from the molding area, said die plate being further provided with two sets of retaining grooves opening out into the molding area, the grooves of one set being parallel with one another and with opposing inner sides of the die ring and spaced apart from one another` and from said sides'of the die ring, and the grooves of the other set being also parallel with one another and the remaining inner sides of the die ring and spaced apart as aforesaid, the grooves of one set crossing at substantially right 'angles the'grooves of the other set, the two sets of grooves dividing the molding area into a plurality of border subareas located next adjacent the die ring, and, in addition, a plurality of inner sub-areas disposed inwardly of the border sub-areas, a projection lo cated in each sub-area with a cavity at its upper end, a ne wire mesh hood individual to each sub-molding area and providing the forming surface of the same, the hoods associated with the border sub-areas having marginal portions extending beneath the contiguous portion of the die ring and removably clamped between the same and the peripheral area of the die plate, and other marginal portions frictionally retained in the grooves dening the border sub-area with which the hood is associated, each of the hoods associated with the inner sub-areas having flanges at their marginal edges retained solely by friction in the grooves defining the sub-area with which the hood is associated, whereby each hood associated with the inner sub-areas may be re moved from the front of the die and replacement hoods substituted without disturbing the die ring or removing any of the other hoods associated with either the inner sub-areas or the border subareas.

5. In an open-face pulp molding die-unit for the suction formation of molded pulp egg flats or analogous articles, in combination, a unitary die-plate having a molding area, a die-ring disposed adjacent to said die-plate, the inner wall of said die-ring defining the molding area and the edge of the article to be molded, said die-plate being provided with drainage openings leading therethrough from the molding area, said dieplate being additionally provided with a perimetric groove at the margin of the molding area and opening out through the molding area of the die-plate just inside the inner wall of the disring, said molding area being divided into a plu- -rality of minor molding areas by spaced grooves opening out through the molding area of the di'eplate, each such minor molding area being thus defined by a minor perimetric groove, each said minor molding area having a conformation corresponding to the section of the article to be molded thereon, a plurality of wire mesh screen hoods snugly engaging the die-plate over a minor molding area thereof, each hood having marginal flanges extending into the contiguous grooves deiining the perimeter of the minor molding area, each of said hoods being rictionally locked within its respective perimetric groove, whereby each of the individual hoods may be initially positionedY or replaced from the face side of the unitary dieplate and is held in place independently oi the die-ring.

6. In an open-face pulp molding die-unit for the suction formation of molded pulp egg flats or analogous articles, in combination, a unitary dieplate having a molding area and a peripheral portion surrounding the molding area, a die-ring secured to the peripheral portion of the die-plate, the inner wall of said die-ring dening the molding area and the edge of the article to be molded, said die-plate being provided with drainage openings leading therethrough from the molding area, said die-plate being additionally provided with a perimetric groove within the molding area and opening out through the molding area of the die-plate just inside the inner wall of the die-ring, said die-plate being further provided with spaced grooves opening out through the molding area of the die-plate and intersecting said perimetric groove and forming minor molding areas each defined by a minor perimetric groove, each said minor molding area having a conformation corresponding t the section of the article to be molded thereon, a plurality of wire mesh screen hoods each snugly engaging the dieplate over a minor molding area thereof, each hood having marginal flanges extending into the contiguous grooves dening the perimetric groove of a minor molding area, each of said hoods being frictionally locked within its respective perimetric groove, whereby each of the individual hoods may be initially positioned or replaced from the face side of the unitary die-plate and is held in place independently of the die-ring.

7. In an open-face pulp molding die-unit for the suction formation of molded pulp egg flats or analogous articles, in combination, a unitary die-plate having a substantially parallelogrammatic molding area and a peripheral portion surrounding the molding area, a die-ring secured to said lperipheral portion of the die-plate, the inner wall of said die-ring dening the substantially parallelogrammatic molding area and the edge of the article to be molded, said die-plate being provided with drainage openings leading therethrough from the molding area, said dieplate being additionally provided with a perimetric groove within the molding area and opening out through the molding area of the die-plate just inside the inner wall of the die-ring, said die-plate being further provided with two sets of intersecting grooves, the grooves of one set being spaced apart and substantially parallel with one another, the grooves of the other set being spaced apart substantially parallel with one another and crossing the grooves of the rst set to form minor molding areas of parallelogrammatic shape and each defined by a minor perimetric groove, all of said intersecting grooves opening out through the molding area of the die-plate, each said minor molding area having a conformation corresponding to the section of the article to be molded thereon, a plurality of Wire mesh be initially positioned or replaced from the face l side of the unitary die-plate and is held in place independently of the die-ring.

ERNEST L. SHEPARD.

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

UNITED STATES PATENTS Number Name Date Re. 11,176 Medbery July 7, 1891 Re. 14,262 Rivers Feb. 20, 1917 596,419 Borrowe et al Dec. 28, 1897 832.215 Sheldon Oct. 2, 1906 372,345 Hammer Dec. 3, 1907 1,158,635 Chaplin Nov. 2, 1915 1,492,555 Cooper May 6, 1924 1,549,903 Buel Aug. 18, 1925 1,701,238 Kennedy Feb. 5, 1929 2,000,085 Maginnis May 7, 1935 2,015,139 Dustan Sept. 24, 1935 2,069,448 Ireland et al Feb. 2, 1937 2,079,667 Swift May 11, 1937 2,081,740 Farnham May 25, 1937 2,192,937 Shepard Mar. 12, 1940 2,238,853 Shepard Apr. 15, 1941 2,359,201 Chaplin et al Sept. 26, 1944