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Número de publicaciónUS3577315 A
Tipo de publicaciónConcesión
Fecha de publicación4 May 1971
Fecha de presentación28 Ago 1968
Fecha de prioridad28 Ago 1968
Número de publicaciónUS 3577315 A, US 3577315A, US-A-3577315, US3577315 A, US3577315A
InventoresFranklin George H
Cesionario originalFranklin George H
Exportar citaBiBTeX, EndNote, RefMan
Enlaces externos: USPTO, Cesión de USPTO, Espacenet
Foraminous forming rolls for a papermaking machine produced from synthetic resins
US 3577315 A
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Descripción  (El texto procesado por OCR puede contener errores)

May 4, 1971 e. H. FRANKLIN 3,577,315

'FORAMINOUS FORMING ROLLS FOR A PAPERMAKING momma raonuczo FROM SYNTHETIC RESINS Filed Aug. 28, 1968 3 Sheets-Sheet 1 //v VENTOR GEORGE h. Emma/1v FIGA a/M A TTORN Y y 4, 1'971 e H. FYRANKLIN I 3,577,315

FORAMiNOUS FORltdING ROLLS FOR A PAPERMAKING MACHINE PRODUCED FROM SYNTHETIC RESINS Filed Aug. 88) 1968 I5 Sheets-Sheet 2 //Vl/EN TOR GEORGE A. fkAN/a/A/ BY 1621arroawtv May 4, 1971 G.. H. FRANKLIN 3,577,315

- FORAMINOUS FORMING ROLLS FOR A PAPERMAKING MACHINE PRODUCED FROM SYNTHETIC RESINS Fnad Aug. 28, l968 5 Sheets-Sheet 3 canon:

DIUQIGOOOOGOIIOO ptulaln o l F'IG.13 BY INVENTOR. Gaol?- I kAIVKLIN ATTORNEY United States Patent 3,577,315 FORAMINOUS FORMING ROLLS FOR A PAPER- MAKING MACHINE PRODUCED FROM SYN- THETIC RESINS George H. Franklin, 734 Bliss Road, Longrneadow, Mass. 01106 Continuation-impart of application Ser. No. 610,280,

Jan. 19, 1967. This application Aug. 28, 1968, Ser.

Int. Cl. D21f 1/60, 3/10 U.S. Cl. 162-210 27 Claims ABSTRACT OF THE DISCLOSURE Forming rolls, such as the dandy rolls and the cylinder molds employed in the papermaking art, are fabricated from synthetic resins to reduce their weight and cost while increasing the corrosion resistance and ease of fabrication thereof to provide highly porous structures facilitating 'water passage. The structure of the invention comprises a hollow cylindrical foraminous body portion with head members at each end thereof to provide for mounting. The body portion is comprised of circumferentially extending support means spaced along the length thereof and a multiplicity of axially extending stiflening rods and top rods arranged about the circumference thereof, the support means in part lying radially outwardly of the stiffening rods, and the top rods lying radially outwardly of the support means. The winding wire and screen are supported upon the top rods, and may be synthetic resin if so desired.

REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of my copending United States application Ser. No. 610,280 filed Jan. 19, 1967, now abandoned.

BACKGROUND OF THE INVENTION Forming rolls known as dandy rolls and cylinder molds are extensively employed in the production and finishing of paper. It is essential that such rolls be not only rigid and strong but also that the forming surfaces thereof be true. These rolls, which are invariably constructed of metal, such as steel, bronze, Monel, etc., are commonly available in a wide variety of lengths and diameters, the diameter of the roll employed depending predominantly upon the linear speed of the paper web-forming operation, the higher speeds requiring the larger diameter rolls. As a result of the trend for increasing production speed, the current demands of the industry are for large diameter rolls.

Not only are such desirably large metal rolls inherently more expensive and costly to manufacture, but their weight makes them difiicult to handle and use. Most significantly, however, the provision of satisfactory rigidifying and support means to prevent distortion and sagging in such heavy rolls becomes more difficult and limiting upon size, or produces a reduction in porosity.

In addition to the aforementioned difficulties, acidic and caustic solutions normally involved in various papermaking processes tend to severely diminish the useful life of the apparatus employed. Attempts have been made to overcome the efiects of such corrosive liquids by the use of corrosion-resistant alloys, but this solution is generally unsatisfactory because such alloys are normally expensive and because problems in fabrication are increased. Additionally, electrolytic corrosion may take place when dissimilar materials are used for the bearing supports.

Furthermore, when such forming rolls are fabricated from metals, it is necessary to produce them in a multiplicity of sections to be subsequently joined, such as by methods which include welding, brazing and soldering techniques. This is not only time consuming and expensive but can result in a reduction of the desirable properties of the metals joined. Special care must be taken to avoid welds which will be subject to corrosion more rapidly than the surrounding metal.

It is an object of the present invention to provide forming rolls for use in the papermaking and other arts which are readily and economically fabricated of synthetic resinous materials to provide a highly porous and long-lived structure.

It is also an object to provide such rolls which are lighter in weight than comparably sized prior art rolls to permit facile increase in diameter and length.

Another object is to provide such forming rolls which are convenient to handle, have high levels of resistance to corrosion and which facilitate the water-marking step in high-speed paper production.

Still another object is to provide a method of fabricating such rolls which is convenient and economical and which entails a minimum number of operations.

A further object is to provide a simple and highly effective method for making paper utilizing such forming rolls and which minimizes the difiiculties in ensuring uniform characteristics across the paper width despite variations in thickness of the fiber deposit.

SUMMARY OF THE INVENTION It has now been found that the foregoing and related objects and advantages may be readily attained in a foraminous forming roll comprising a hollow cylindrical body portion and head members at each end thereof, all fabricated of synthetic resin. The body portion is comprised of a multiplicity of axially extending stiffening rods spaced about the circumference thereof and generally circumferentially extending support means supported by the stiffening rods and spaced along the length of the body portion. A multiplicity of axially extending top rods is spaced about the outside circumference of the body portion upon the support means. The spacing between the stiffening rods, support means and top rods provides a multiplicity of passageways at axially and circumferentially spaced locations for communication between the inside and outside of the forming roll. The stiffening rods, support means and top rods comprising the body portion are fabricated from a resinous material selected from the group consisting of thermoplastic and thermosetting resins, and may be integrally molded if so desired. The head members are formed separately from the body portion and are subsequently secured to the ends thereof.

As a result, a rigid and strong structure is fabricated which may be circumferentially wound with suitable winding wire or cable and then covered with a screen or fabric to produce a forming roll useful in the paperma king art. Large diameter structures may readily and economically be produced without encountering excessive weight limitations.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary front elevational view of a forming roll embodying the present invention with different roll mounting means at the two ends for purposes of illustration;

FIG. 2 is a sectional view of the forming roll of FIG. 1 along the line 22 thereof;

FIG. 3 is a sectional view of the roll mounting member of the forming roll of FIG. 1 along the line 3--3 thereof;

FIG. 4 is a fragmentary front elevational view of another embodiment of the forming roll of the present invention;

FIG. 5 is a fragmentary perspective view to an enlarged scale showing a top rod in the central portion of a forming roll of the present invention and its relationship to the winding wire and covering fabric;

FIG. 6 is a fragmentary front elevational view of a central portion formed in accordance with the present invention to provide a cylinder roll;

FIG. 7 is a sectional view taken along the line 7-7 of FIG. 6;

FIG. 8 is an elevational view of an embodiment of a head member for the cylinder roll of FIG. 6;

FIGS. 9-11 are end views of other embodiments of a body portion for the forming rolls of the present invention;

FIG. 12 is a sectional view of the body portion of FIG. 11 taken along the line 1212 thereof; and

FIG. 13 is a front elevational view of a cylinder roll with a suction box therein to facilitate removal of the water from the sheet and with portions of the top screen, winding wire and top and stiffening rods broken away for purposes of illustration.

DESCRIPTION OF THE PREFFERED EMBODIMENTS Referring now in detail to the embodiment of FIGS. l-3, a forming roll of the present invention is illustrated as having a cylindrical central or body portion generally designated by the numeral 12 of considerable axial length and two embodiments of head or roll mounting members, i.e., trunnion head and a journal head generally designated by the numerals 114 and 16, respectively. The body portion 12 comprises a plurality of internal stiffening rods 18, support means in the form of a plurality of ringor hoop-shaped members 20, and a plurality of top rods 22. The stiffening rods 18 extend axially and are spaced about the circumference of the body portion 12, and the ringshaped members 20 extend generally circumferentially about the stiffening rods 18 and are positioned at spaced locations along the length of the body portion 12. Spaced about the outside circumference of the body portion 12 upon the support means 20 is the plurality of axially extending top rods 22.

At each end of the central portion 12 are head or rollmounting members, two embodiments of head members being shown only for the purpose of illustration. The trunnion-type member 14 has a bearing surface 34 provided to protect the head member from undue wear and a radial collar 35 with an inner shoulder 36 of lesser diameter. Similarly, the journal-type member (16 has a shaft 28 with a collar thereon providing a bearing surface and a thrust surface 32. A radial collar 39 with an inner shoulder 41 of lesser diameter butts against the adjacent ring 20 and supports the ends of the top rods 22. In this manner, the head members may be secured to the body portion 12.

Extending about the body portion 12 is a winding wire 24 spirally wound in grooves 42 (seen in FIG. 5) in the outer surface of top rods 22. Carried in turn upon the winding wire 24 is a top fabric or screen 26 which may provide the surface upon which a paper web is formed.

The body portion 12 may be formed of synthetic resin in a single molding operation or it may be only partially molded, or it may be fully assembled from component parts which are adhered together by adhesives, solvents or heat. Head members 14 and 16 are formed in a separate operation and subsequently affixed adjacent the ends of the central portion 12 by suitable means such as adhesives or welding. If so desired, mechanical means may be utilized. Also in subsequent operations, the central portion 12 is wound with the winding wire 24 which in turn is covered with top fabric 28, both of which may advantageously be composed of synthetic resinous materials.

Referring now in detail to FIG. 2, the cross-sectional configuration of the stiffening rods 18 and top rods 22 is best illustrated. The stiffening rods \18 are triangular in cross section with the apices thereof directed inwardly 4 of the body portion 12. Similarly, the top rods 22 have a generally triangular cross section with the apices thereof directed outwardly. The stiffening rods 18 carry the sup port means 20 which in turn support the top rods 22.

FIG. 3 shows one embodiment of a journal-type head member 16 with the axially extending shaft 28 and radially extending spokes 38 supporting the circumferential collar 39 which supports and is secured to the body portion 12.

Referring now to FIG. 4, an alternative embodiment of the support means is illustrated. Instead of a multiplicity of ring-like support means 20, only two such members are employed adjacent the ends of the body portion 12. The stiffening rods 18 carry a band of material molded as a helical or spiral strip 40 wound about the outside surface of the stiffening rods over substantially the entire length thereof between the two ring-shaped support means 20.

FIGS. 6 and 7 show an embodiment of the present invention wherein a high degree of structural strength and rigidity is provided, particularly for use as a cylinder roll. The numbers of stiffening rods 18, support rnigs 20 and top rods 22 are increased with the spacing therebetween decreased.

FIG. 8 illustrates another embodiment of a journaltype head member which is suitably employed in conjunction with the reinforced body portion 12 depicted in FIGS. 6 and 7. The head member 116 has a shaft 128 with a collar providing a bearing surface and a thrust sur-- face 13-2. The multi-arched element 160 which is the radial support for the collar 139 provides a particularly strong and rigid construction.

In the embodiment of FIG. 9, the stiffening rods 140 are of circular cross section and extend between the rings 142 at about the midpoint of the width of the rings at a multiplicity of points spaced about the circumference thereof. The top rods 144 are of rectangular cross section and extend therebetween about the outer circumference of the rings 142. When the body portion is assembled from the several parts rather than being molded, the rings 142 are formed with circular apertures therein to receive the stiffening rods 140 which extend therethrough over the full axial length of the body portion. Similarly, the rings 142 are formed with recesses or notches in their outer periphery to seat the top rods 144 which extend over substantially the full length of the body portion.

The embodiment of FIG. 10 is similar to that of FIG. 9 with rings 152 and round stiffening rods extending therebetween. However, the top rods 154 have a round cross section and are seated in arcuate recesses in the outer periphery of the rings 152.

In the embodiment of FIGS. 11 and 12, the stiffening rods in part are seated in apertures in the rings 162 at about the midpoint thereof and in part seated in arcuate recesses about the inner periphery thereof. As seen, the two forms of mounting for the rods 160 in the rings 162 are alternated about the circumference of the rings 162. The top rods 164 are triangular in cross section and seat in recesses 166 formed in the outer periphery of the rings 162.

In FIG. 13, the forming roll of FIGS. 1-3 has been modified to provide a cylinder roll incorporating a suction box to facilitate withdrawal of water from the Web. The same reference numerals and description of the embodiment of FIGS. 1-3 are applicable here except that the cylinder roll now has a suction box, generally designated by the numeral 200, seated therein between the trunnion head 14 and journal head 16. Basically, it is provided by a pair of radially spaced cylinders 202, 204. The inner cylinder 202 is imperforate and the outer cylinder 204 is spaced closely adjacent the stiffening rods 18 and has a multiplicity of small apertures 206 therein (shown in exaggerated size) by which suction may be applied to the inner surface of the web on the fabric 26. A suction line 208 extends from an opening in the outer cylinder 204 through the shaft 28 of the journal-type member 16 to a suitable source of vacuum (not shown). In this illustration, roller bearings 210 for carrying the roll are disposed about the bearing surface 34 of the trunnion-type member 14.

The body portions of the forming rolls of the present invention may be fabricated as integral units by molding or they may be assembled from ring, stiffening rod and top rod components. The latter procedure offers initial economy in that expensive and relatively complicated molds are not required for a variety of sizes but the former procedure offers reduced labor costs and a rugged assembly. When molding is employed, the entire body portion comprised of the stiffening rods, support means and top rods may be molded in a single operation or in two or more steps to facilitate more complex formations and mold removal. Both compression and injection molding techniques may be employed depending upon the resin selected. It will be appreciated that the molds will be fabricated in several sections to facilitate removal of the body member therefrom, and the inner or core mold will normally be formed of a plurality of segments held in expanded position by a plug so as to collapse upon removal of the plug.

When the body portion is fabricated from component parts, the top and stiffening rods may be extruded in the desired configuration and may be drawn under conditions to achieve uniaxial orientation if so desired for a high degree of strength in the axial direction. Alternatively, bar stock may be machined, or the rods may be molded. The rings are desirably molded into the desired configuration although they may be cut and machined from heavy gauge sheet stock if so desired. The rods and rings may be assembled readily by adhesive techniques, most conveniently involving the use of an interposed coating of highstrength adhesive to ensure firm bonding between the opposed surfaces of rods and rings. By providing closely fitting apertures and notches for the rods in the rings, some measure of frictional retention can also be employed. However, solvent adhesion may be utilized to render the opposed surfaces tacky for bonding to each other, and heat or ultrasonic bonding may be used with thermoplastic materials.

The resinous material which is employed may be any moldable material which has the necessary characteristics of strength and rigidity. The particular resin selected will depend upon the application of the roll from the standpoints of corrosive environment, temperature and loading. A material which exhibits a high level of resistance to stress and retains its properties after aging should most desirably be employed. Examplary of the materials which are suitable for use in the rolls of the present invention are the polycarbonates, caprolactams, polyfiuorohydrocarbons, polypropylenes, acetals, epoxy and urea-formaldehyde resins. Depending on the techniques of fabrication, fiber-jelled materials may be used for enhanced strength.

The axially extending elongated stiffening rods are positioned at spaced intervals around the inside circumference of the body portion of the forming roll. These members serve to reinforce against sagging in the central portion and also serve to give axial strength to the member. Generally, the stiffening rods extend slightly less than the entire length of the central portion so that a shoulder portion of the head members will abut or seat the ends of the stiffening rods within the central portion at each end thereof.

When molding techniques are employed, the stiffening rods have a generally triangular cross section, the apices of which are directed inwardly of the forming roll. This configuration is desirable not only from the standpoint of structural strength, but also because it facilitates mold release. The triangular stiffening rods should be wide enough at their base to provide the desired degree of strength and support but yet sufficiently narrow to allow rapid drainage through the roll surface. However, other configurations may be employed readily when the body portion is fabricated from component parts. In addition to the round stiffening rods illustrated in FIGS. 9-12, rectangular and other polygonal configurations may be employed.

The support means extends generally circumferentially about the stiffening rods. The support means includes two or more axially spaced rings or hoops encircling the stiffening rods with at least one ring positioned adjacent to each end of the central portion.

In one embodiment, the support means comprises a multiplicity of such rings positioned at spaced intervals along the length of the body portion. In another embodiment, the support means includes a band of material molded as a helical or spiral strip 'wound about the outside surface of the stiffening rods over substantially the entire length thereof between the rings or hoops at the end thereof. This configuration has the advantage of adding additional radial rigidity and lends an increased degree of resistance to twisting moments.

The width and height of the support means will be that which gives the required strength without unduly constricting drainage through the surface of the forming roll. Its shape is generally dictated by the fabricating technique employed, and the support means will usually be formed with a substantially rectangular cross section or with a slight taper to facilitate mold release when molding is employed. It can be seen that the support means ties together the stiffening and support rods and serves to distribute stresses and resist twisting moments.

The top rods generally extend over the entire length of the body portion and are spaced about the periphery of the support means. The top rods not only strengthen and rigidity the assembly but also support windings and top fabrics. The top rods may be of any shape including triangular, rectangular and circular. Particularly when the body portion is being molded, it is generally preferred to form them with a substantially triangular cross section, the apices of which are directed outwardly. This configuration facilitates mold release and allows a high volume of drainage through the forming roll while nevertheless lending strength thereto and providing good support for the outside layers irrespective of the fabricating technique employed.

It should be noted that in order to facilitate molding, it is usually preferred to position the top rods and stiffenmg rods at radially non-aligned locations around the circumference of the forming roll so that there is no radial overlapping of stiffening and top rods.

Head members are provided adjacent each end of the central portion to provide end supports for the forming roll for rotation thereof and also to strengthen the structure. These head members may be of any type such as the journal or trunnion type, and include means for attachment to the central portion, if necessary, as well as auxiliary parts, such as chime rings and clamping rings. They are desirably configured with a radial collar and an inwardly extending shoulder for insertion in the ends of the body portion to abut the ends of the stiffening rods and the end rings of the support means with the top rods resting on the periphery of the shoulder and abutting against the radial collar. If so desired, the head members may have suitably configured recesses in their inner surface to seat the ends of the stiffening rods for even greater coupling strength between the head members and body portion.

When a journal-type head is employed, it includes means such as spokes or arms, extending generally radially from a central hub to points on the collar forming the periphery of the head member, each hub including an outwardly extending shaft portion which may extend throughout the axial length of the body portion as a shaft to provide increased rigidity and minimize the effect or torque due to differential speeds at the opposite ends.

Although the head members may be formed of any material which will provide the necessary rigidity, strength and support for the roll, it is preferred to mold the head members out of a synthetic resinous material. The resinous material employed need not be the same as that which is used for the central or body portion and should be chosen with the particular function of the end members in mind. It is highly advantageous to mold the head members of synthetic materials since it is then possible to join the head members to the central portion by a technique such as adhesive bonding, thermowelding, solvent bonding, ultrasonics, or by other convenient means. It should be appreciated that head members fabricated of synthetic resins will most desirably have separately formed synthetic plastic or metallic bearing and thrust surfaces such as by the provision of sleeves, to prevent undue wear of the head member.

Theouter surface of the top rods is provided with notches or grooves along the length thereof to accommodate and position a winding wire or cable which is usually spirally wound with spacing to allow for drainage therethrough. Although the wire may be of any material which is commonly used in the art, such as copper, brass, etc., it is preferably a synthetic resin, and most desirably a monoaxially oriented fiber for optimum strength. This not only serves to further decrease the overall weight of the member, but use of a Winding ca-ble composed of a suitable synthetic resin will further enhance the corrosion resistant characteristics mentioned previously with regard to the body portion.

At least one foraminous screen or fabric on top of the winding cable will generally be provided to complete the forming roll. As in the case of the winding cable, the fabric may be one which is currently employed in the art, i.e., a fabric made of brass, bronze, Monel, etc.; however, this, too, is most advantageously formed or woven from fiber of a synthetic resin.

The rolls made in accordance with the present invention generally have lengths ranging from about 48 to 300 inches, although longer or shorter rolls can also be molded. As was previously mentioned, the diameters of the rolls will vary with the speed of the machine on which they are to be employed; however, rolls ha'ving diameters ranging from less than about inches to more than about 40 inches are typical.

As was previously indicated, the forming rolls of the present invention are particularly advantageously employed as dandy rolls and cylinder molds. Although the construction of both of these types of rolls essentially is the same, the cylinder mold must generally be stronger due to the greater pressures which it encounters. Therefore, a cylinder mold will normally be fabricated with a greater number of stiffening and top rods than a dandy roll, and the support means provided will usually be more closely spaced and of greater cross section than in the case of dandy rolls.

As previously indicated, the roll members may be equipped with additional elements to facilitate the forming operation in view of their light weight. Thus, a cylinder roll can include therewithin a suction box to assist in draining the water from the web without unduly increasing the weight of the assembly. The components used for the auxiliary elements are desirably fabricated from synthetic plastic materials to maintain the long life of the forming roll and minimize maintenance while at the same time minimizing the overall weight of the assembly.

The forming rolls of the present invention offer significant advantages in operation because of their light weight and high damping characteristics. The bearing supports and drive elements for the rolls may be simplified and reduced in bearing or drive capacity with attendant I savings in maintenance and operation costs. Moreover, the light weight of the rolls allows them to be mounted so as to be supported by the paper web itself, i.e., so as to ride freely on the surface of the web being formed 'with a restraint being superposed to prevent the roll from rising from the surface of the web or a controlled pressure applied thereto to increase the pressure applied to the surface of the web. This is in contrast with conventional roll mounting techniques which require substantial supports to hold the roll up in position to avoid excessive pressure upon the sheet. Because the synthetic plastic has high damping characteristics, the tendency of the rolls to chatter or vibrate is substantially eliminated with atte-ndant savings: in wear on the operating equipment and improvement in the surface quality of the web being formed. Moreover, the resilience of the synthetic plastic allows the rolls to adapt and conform to variations in the thickness of the web along the axial length thereof so as to maintain the uniform surface finish over the width of the web. Many operating advantages are to be found in the use of the rolls of the present invention in addition to the obvious fabricating and maintenance advantages.

Thus, forming rolls useful in the papermaking and other arts may be readily and economically fabricated of synthetic resinous materials to provide diameters larger than those heretofore practicable. The rolls are lighter in weight than comparably sized prior art rolls and lend themselves to revised mounting techniques. The forming rolls of the present invention are convenient to handle, exhibit high levels of resistance to corrosion and, because of the large diameters which are possible, facilitate the water-marking step in high-speed paper production. Vibration and surface aberration in the paper as a result of variations in the thickness of the web across the width thereof may be substantially eliminated. The invention, furthermore, is adapted to a method of fabricating such rolls which is convenient and economical and which entails a minimum number of operations.

Having thus described the invention, I claim:

1. In a foraminous forming roll, a hollow cylindrical body portion comprised of a multiplicity of axially extending stiffening rods spaced about the circumference thereof, generally circumferentially extending support means supported by said stiffening rods and disposed at a multiplicity of axially spaced locations along the length of said body portion with at least a portion of said support means lying radially outwardly of said stiffening rods, and a multiplicity of axially extending top rods spaced about the outside circumference of said body portion and supported upon said support means, said top rods lying radially outwardly of said stiffening rods, the spacing between said stitfening rods, support means and top rods providing a multiplicity of generally radially extending passageways at axially and circumferentially spaced locations for communication between the inside and outside of said forming roll, said stiffening rods, support means and top rods comprising said body portion being formed from a material selected from the group consisting of thermoplastic and thermosetting resins.

2. The roll of claim 1 wherein said generally circumferentially extending support means includes at least two axially spaced rings encircling said stiffening rods with at least one positioned adjacent each end of said body portion.

3. The roll of claim 1 wherein said generally circumferentially extending support means includes a helical strip wound about the radially outer surface of said stiffening rods, said strip extending over substantially the entire length of said body portion.

4. The roll of claim 1 wherein said stiffening rods and top rods are generally triangular in cross section, the apices of the cross section of said stiffening rods being radially inwardly directed and the aspices of the cross section of said top rods being radially outwardly directed.

5. The roll of claim 1 wherein said stifiening rods are at least in part seated in apertures in said support means and wherein said support means comprises a multiplicity of rings spaced axially along the length of said body portion.

6. The roll of claim 1 wherein said top rods are of generally circular cross-section and are mechanically fitted to said support means by recesses in one of said support means and top rods seating the other of said support means and top rods.

7. The roll of claim 1 wherein said stiffening rods, top rods and support means are adhesively engaged.

8. The roll of claim 1 wherein said stiffening rods, top rods and support means are molded as an integral unit.

9. In a foraminous forming roll, the combination comprising a hollow cylindrical body portion and a head member at each end thereof, said body portion being comprised of a multiplicity of axially extending stiffening rods spaced about the circumference thereof, generally circumferentially extending support means supported by said stiffening rods and disposed at a multiplicity of axially spaced locations along the length of said body portion with at least a portion of said support means lying radially outwardly of said stiffening rods, and a multiplicity of axially extending top rods spaced about the outside circumference of said body portion and supported upon said support means, said top rods lying radially outwardly of said stiffening rods, the spacing between said stiffening rods, support means and top rods providing a multiplicity of generally radially extending passageways at axially and circumferentially spaced locations for communication between the inside and outside of said forming roll, said stiffening rods, support means and top rods Comprising said body portion being formed from a material selected from the group consisting of thermoplastic and thermosetting resins, said head members being formed separately from said body portion and secured to the ends thereof.

10. The roll of claim 9 wherein said generally circumferentially extending support means includes at least two axially spaced rings encircling said stiffening rods with at least one positioned adjacent each end of said body portion.

11. The roll of claim 9 wherein said generally circumferentially extending support means includes a helical strip wound about the radially outer surface of said stiffening rods, said strip extending over substantially the entire length of said body portion.

12. The roll of claim 9 wherein said head members have a radially extending circumferential collar and a shoulder of lesser diameter extending radially inwardly therefrom, said top rods seating on said shoulder and said head members providing an axial abutment surface for said top rods, stiffening rods and support means.

13. The roll of claim 9 wherein said body portion is circumferentially wound with support wire and a waterpermeable fabric is disposed thereon.

14. The roll of claim 13 wherein said support wire and fabric are fabricated from synthetic resin.

15. The roll of claim 9 wherein said top rods have recesses in the outer edge thereof over substantially the entire length thereof in. which said support wire is seated.

16. The roll of claim 9 wherein said stiffening rods are at least in part seated in apertures in said support means and wherein said support means comprises a multiplicity of rings spaced axially along the length of said body portion.

17. The roll of claim 9 wherein said stiffening rods, top rods and support means are molded as an integral unit.

18. The roll of claim 9 wherein said stiffening rods, top rods and support means are adhesively engaged.

19. The roll of claim 9 wherein a cylindrical suction box is included within said body portion and has a foraminous outer surface through which suction may be applied to the inner surface of the paper web being formed and wherein a suction conduit extends from said suction box through at least one of said head members.

20. In a method for fabricating a foraminous forming roll, the steps comprising:

(a) forming from a synthetic resin a hollow cylindrical body portion, said body portion being comprised of a multiplicity of axially extending stiffening rods spaced about the circumference thereof, generally circumferentially extending support means supported by said stiffening rods and disposed at a multiplicity of axially spaced locations along the length of said 'body portion with at least a portion of said support means lying radially outwardly of said stiffening rods, and a multiplicity of axially extending top rods spaced about the outside circumference of said body potrion and supported upon said support means, said top rods lying radially outwardly of said stiffening rods, the spacing between said stiffening rods, support means and top rods providing a multiplicity of generally radially extending passageways at axially and circumferentially spaced locations for communication between the inside and outside of said forming roll;

(b) forming head members of a synthetic resinous material and securing said head members to each end of said body portion;

(c) spirally winding a support wire about substantially the entire length of said body portion; and

(d) positioning a foraminous fabric atop and adjacent said top rods and support wire over substantially the entire length and circumference of said body portion.

21. The method of claim 20 wherein said top rods are formed with recesses in the outer edge thereof over substantially the entire length thereof in which said support wire is seated during said winding.

22. The method of claim 20 wherein said head members are formed with a radially extending circumferential collar and a shoulder of lesser diameter extending axially inwardly therefrom, and wherein said top rods are seated on said shoulder with said head members providing an axial abutment surface for said top rods, stiffening rods and support means.

23. The method of claim 20 wherein said body portion is molded as an integral unit during the forming operation.

24. The method of claim 20 wherein said stiffening rods, top rods and support means are separately formed components and are adhesively engaged during the formmg operation.

25. In the method of making paper, the steps comprising mounting on a papermaking machine for limited movement in a direction perpendicular to the passage of the paper web thereby a forming roll having a hollow cylindrical body portion and a head member at each end thereof, said body portion being comprised of a multiplicity of axially extending stiffening rods spaced about the circumference thereof, generally circumferentially extending support means supported by said stiffening rods and disposed at a multiplicity of axially spaced locations along the length of said body portion with at least a portion of said support means lying radially outwardly of said stiffening rods, and a multiplicity of axially extending top rods spaced about the outside circumference of said body portion and supported upon said support means, said top rods lying radially outwardly of said stiffening rods, the spacing between said stiffening rods, support means and top rods providing a multiplicity of generally radially extending passageways at axially and circumferentially spaced locations for communication between the inside and outside of said forming roll, said stiffening rods, support means and top rods comprising said body portion being formed from a material selected from the group consisting of thermoplastic and thermosetting resins, a support wire circumferentially wound about the body portion, and a water-permeable fabric supported on said support wire; passing the wet web of paper into contact with the fabric of the forming roll; and allowing the forming roll to conform substantially to the surface of the web and to impart a substantially uni- 1 1 form surface finish thereto over substantially the full width therof despite variations in thickness occurring during operation.

26. The method in accordance with claim 25 wherein said roll is mounted so as to be supported upon the surface of the wet web of paper.

27. The method in accordance with claim 25 wherein said roll is a cylinder roll and includes a suction box in said body portion and is mounted so that said paper web passes thereover and wherein suction is applied to said suction box to facilitate withdrawal of water from said paper web passing thereo ver.

1 2 References Cited UNITED STATES PATENTS 5/1969 Johnston 162357 '3/1970 Gregersen et al. 29-432 S. LEON BASHORE, Primary Examiner R. H. TUSHIN, Assistant Examiner US. Cl. X.R.

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Clasificaciones
Clasificación de EE.UU.162/210, 156/172, 162/372, 156/242, 492/32, 162/314, 162/217, 162/357
Clasificación internacionalD21F1/00, D21F1/46
Clasificación cooperativaD21F1/46
Clasificación europeaD21F1/46