US3905290A

US3905290A - Self-feeding press for producing strip material

Info

Publication number: US3905290A
Application number: US499935A
Authority: US
Inventors: Robert A Caughey
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-12-21
Filing date: 1974-08-23
Publication date: 1975-09-16
Anticipated expiration: 1992-09-16

Abstract

A press for compacting and integrating material to form a continuous strip comprising spaced parallel arrays of long narrow bars, a frame supporting the bars in each array for reciprocal movement, a feeder for supplying material to the space between the arrays of bars at one end of the press, rams for effecting relative movement of the arrays of bars toward each other to apply compacting pressure, and rams for effecting longitudinal movement of the bars in each array in a predetermined succession in one direction and for retracting all of the bars in consonance in the other direction.

Description

[ Sept. 16, 1975 SELF-FEEDING PRESS FOR PRODUCING STRIP MATERIAL Robert A. 'Caughey, Clinton Rd., Antrim, NH. 03440 22 1 Filed: Aug. 23, 1974 21 Appl. No.: 499,935

Related US. Application Data [63] Continuation of Serv No. 317,136, Dec. 21, 1972,

[76] Inventor:

abandoned.

[52] US. Cl. 100/215; 100/222; 100/295; 425/338; 425/406 [51] Int. Cl. B30B 15/30 [58] Field of Search 100/144, 215, 222, 224,

[56] References Cited UNITED STATES PATENTS 3,577,304 5/1971 Guyer 156/555 Primary Examiner--William A. Powell Assistant Examiner--Brian J. Leitten Attorney, Agent, or Firm-Robert T. Gammons [5 7] ABSTRACT A press for compacting and integrating material to form a continuous strip comprising spaced parallel arrays of long narrow bars, a frame supporting the bars in each array for reciprocal movement, a feeder for supplying material to the space between the arrays of bars at one end of the press, rams for effecting relative movement of the arrays of bars toward each other to apply compacting pressure, and rams for effecting 1ongitudinal movement of the bars in each array in a predetermined succession in one direction and for retracting all of the bars in consonance in the other direction.

15 Claims, 16 Drawing Figures PATENTED ms 3, 905,290

SHLU 1 [IF 5 FIGZ FIG-3 FIGBB PATENTED 5W5 3,905,290

SHEET 2 OF 5 PRESSED STRIP F|G 4 UNPRESSED MATERIAL FIG. 4-?) PISA-4 FIG.4

PATENTEBSEP'I ems SHEETSUFS D C 4. u

w p w O M \o/ 0/ FIGM! FIGIO FIGB FISH

SELF -FEEDING PRESS FOR PRODUCING STRIP MATERIAL This is a continuation of application Ser. No. 317,136, filed on Dec. 21, 1972 now abandoned.

BACKGROUND OF THE INVENTION The object of this invention is to provide a press whereby pressure can be continuously applied to a substrate such as plywood, wood particle molding compound, laminates and the like while the substrate is simultaneously being moved through the press.

The importance of such a press is apparent when consideration is given to the relation of time and temperature in the curing of the adhesive used; for example, in the production of particle board, say inch thick, a pressing time of 8 to minutes may be required in the hot press in order to allow time for the center of the strip to reach curing temperature, it being necessary for heat to be transferred from the surfaces of the press platens through inch of molding compound.

If, however, the molding compound could be quickly brought to press temperature outside the press and then injected into the press in a matter of a few seconds the press time need be only one minute or less since, at the press temperature employed, the resin can be cured in this short period.

However, with conventional presses in which the molding compound is spread on a tray or caul and then injected into the open press, the time involved in preparing the mat on the caul and loading and unloading the press is so great that the molding compound must be handled at low temperature in order to prevent precure of the resin or binder before pressure can be applied. Thus with an intermittent pressing operation it is imperative to use cold molding compound which, in turn, requires that the molding compound be raised to curing temperature in the press. This accounts for long press cycles and requires large equipment to achieve substantial production rate.

If, however, the pressing operation could be made continuous so that the mat of molding compound could be laid in the throat of the press continuously and then moved immediately into the press such that the elapsed time between laying of the mat and application of full pressure (with simultaneous reduction to final thickness) could be accomplished in say 10 to seconds then it would become possible to rapidly preheat the molding compound close to curing temperature and draw it into the high pressure zone in a matter of seconds after preheating without danger of precuring. The elapsed time between mat formation and completion of this finished strip would then be only the nominal cure time of the resin system which might be say one minute, since the press platens need to deliver very little heat to the curing mass. Thus the platen areas required for a given throughput of material would be reduced by the ratio of press time of conventional versus a continuous system. This reduction can be of the order of /3 to 1/6 depending on strip thickness. In fact, with a continuous system, using a preheated substrate, very substantial thickness may be cured in a very short time.

Summary A press for compacting and integrating material while moving through the press comprising spaced parallel arrays of long narrow bars, means supporting the bars in each array for reciprocal movement, means for supplying material to the space between the arrays of bars at one end of the press, and means for effecting longitudinal reciprocal movement of the bars in each array in a predetermined succession in one direction for applying compacting pressure to the material and for retraction of all of the bars in consonance in the other direction to advance the compacted material through the press. Spaced parallel platens support the long narrow bars side-by-side for movement longitudinally and these platens are in turn supported for movement toward each other to enable applying pressure to the material between the bars. Antifriction means in the form of antifriction sheets or roller bearings are disposed between the confronting sides of the platens and the bars to reduce the resistance to sliding movement of the bars relative to the platens. There are rams operably connected to one of the platens for effecting movement toward the other to apply compacting pressure, there is a ram connected to each of the bars to enable advancing each bar independently of every other bar and control means for effecting advance of the bars in a predetermined sequence and retracting the entire number of bars in consonance. At the receiving end of the press the bars at the upper side diverge to facilitate entrance of the unpressed material to the space between the bars. To provide for heating or cooling to effect curing the bars contain passages longitudinally thereof to which a heating or cooling medium is supplied. For particulate material which has very low integrity a carrier web such as paper, a screen or cloth is supported in engagement with the confronting faces of the bars in the two arrays with portions at the entrance end of the press moving toward the entrance to the space between the bars for entraining the uncompressed material and drawing it into the press.

The invention will now be described in greater detail with reference to the accompanying drawings wherein:

FIG. 1 is a plan view of the press;

FIG. 2 is a vertical section taken longitudinally of the press;

FIG. 3 is an elevation at one end of the press;

FIG. 3a is a fragmentary elevation showing a gravitytype feeder;

FIG. 3b is a fragmentary elevation showing a conveyor-type feeder;

FIG. 4 diagrammatically illustrates the sequence of operation of the bars and the travel cycle;

FIG. 5 is a schematic of the electrical control for the press;

FIG. 6 is a schematic of the hydraulic control for the press;

FIG. 7 is a longitudinal section showing the use of conveyor members for inducting particular material into the press;

FIG. 8 diagrammatically illustrates an arrangement of bars for forming an angle section;

FIG. 9 diagrammatically illustrates an arrangement of bars for forming a U-shaped section;

FIG. 10 diagrammatically illustrates an arrangement of bars for forming an eye section;

FIG. 11 diagrammatically illustrates an arrangement of bars for forming a solid rod;

FIG. 12 diagrammatically illustrates an arrangement of bars for forming a hollow cylinder;

FIG. 13 is a transverse section of the press mounted within a frame for longitudinal reciprocal movement; and

FIG. 14 diagrammatically shows means for effecting reciprocal movement of the press.

Referring to the drawings (FIGS. 1, 2 and 3), the press comprises a bottom platen along the opposite longitudinal edges of which there are secured at longitudinally spaced intervals posts l212 on which there is mounted an upper platen 14 corresponding in configuration and size to the lower platen for movement toward and from the lower platen. Header bars 16 mounted on the upper ends of the posts 12-12 provide for a rigid structure and rams 18 mounted between the header bars and the platen 14 provide for effecting movement of the upper platen 14 toward and from the lower platen l0.

Each of the

platens

10 and 14 has at one end, the left end as shown in FIG. 1, an opening 20 within which there are mounted longitudinally spaced

ram cylinders

22, 24 between which there is a common ram 26, the ram cylinders being operable to advance and retract the rams. Two arrays of long narrow bars 27 are mounted between the confronting faces of the platens, there being four bars 29 in each array arranged side-byside, as shown in FIG. 3, with a space 31 therebetween for receiving material to be compacted and integrated. Each bar 29 has a'driving lug 28 mounted to one of the rams 26 by means of which the bars are movable longitudinally and reciprocably with respect to the platens. The bars are slidably supported on the platens, for example, on bars 29 or by dove-tail tongue and groove connections.

To provide for free movement without expenditure of an abnormal amount of power, friction means 30 FIGS. 2 and 7 in the form of strips of antifriction material or roller bearings are disposed between the bars and the platens.

The material which is to be compacted and integrated is introduced to the entrance end of the press (FIG. 2) by means of a suitable dispenser 33 FIG. 3A from which the material gravitates onto the lower one of the platens at the entrance end or by means of a suitable conveyor 35 FIG. 3B for advancing a mat of the uncompressed material to the open end of the press and to facilitate entrance the ends of the upper bars at the entrance end are inclined upwardly relative to the lower bars to provide a converging entrance to the space between the bars. If sheet material such as layers of veneer are to be combined they are pushed along a table provided at the entrance to the press.

The bars 29 may be cored for heating, for example, with steam'or cooled, for example with water.

Hydraulic pressure is applied to the rams to effect operation thereof by means of a pump VP (FIG. 6) driven by a motor M1. A hydraulic motor M2 connected to the hydraulic circuit operates to turn a cam shaft which, in turn, operates to close a series of electric switches LS1 to LS4, inclusive, (FIG. 5). The electric switches when closed energize solenoid-operated valves SVl to SV4, inclusive, which control the rams for moving the bars forwardly and reversely. The cam shaft is designed, as shown in FIG. 6, to supply pressure to rams l and 7, then to

rams

2 and 8, then to

rams

3 and 5 and finally to

rams

4 and 6 to move the aforesaid bars forwardly in that sequence and upon reversal of the valves to supply pressure to the rams of all of the bars at the same time to withdraw all of the bars in consonance.

The operating principle of the press depends on a division of the friction between the substrate, that is, the material being compacted and integrated and the moving bars. In the condition shown diagrammatically in FIG. 4 all of the moving bars are in their extreme left position and bearing substantially equal on the substrate. It is reasonable to assume that the coefficient of friction between the substrate and any one of the moving bars will be substantially the same as with any other bar. Thus if sufficient pressure is applied to drive the bar 1 to the right (FIGS. 1 and 2) while the other seven bars are restrained and assuming that the internal shear strength of the substrate is sufficient to resist shearing force due to the friction between the substrate and the surface of the moving bar then the bar will slide over the substrate while the substrate remains in its original position because of the relatively large amount of friction derived from contact with the other seven bars.

If now

additional bars

2, 3 and 4, etc. are advanced one at a time (FIGS. 4-2, 4-4, 4-5) to the same forward limit as bar 1 then when all eight bars shall have been advanced to the right, the substrate will still be in its original position but the bars will all have traversed over it to the right by the same increment X of travel. If at this point force is simultaneously applied to all eight bars in the reverse direction they will all move simultaneously to the left with respect to the platens, carrying with them the substrate which will then have been advanced to the left by one increment of bar travel. Repetition of this cycle will thus cause the substrate to move from right to left through the press.

By providing one or both sets of bars at the entrance end of the press with divergent or curved portions so as to form an entrance nip the substrate may be compressed in volume as it enters the space between the bars. The configuration of the entrance is designed to conform to the properties and desired deformation of the substrate. For example, in processing veneers, as in plywood manufacture, the reduction at the entrance to the space between the bars would be slight. However, in the production of particle board where thickness reduction may be 3 or 4 to l the divergent relation of the bars to each other at the entrance would have to be substantial.

In the compaction and integration of granular material where the integrity of the mat is very low in the uncompressed condition it is usually necessary to provide a carrier web referred to which may be of paper, screen or cloth to support the material until it shall have been compressed to a degree sufficient to provide an internal shear strength great enough to resist the shear action of the movement of the individual bars. Such a web is shown in FIG. 7 in the form of an endless belt 38 entrained about sheaves 40.

To compensate for variation in density or thickness in the substrate, the press platens may be hydraulically or otherwise loaded to permit some vertical movement while maintaining controlled pressure on the substrate.

The bars as disclosed herein are arranged in spaced parallel arrays in which the bars in each array are situated in a common plane so that the strip produced is flat and has spaced parallel surfaces. It is within the scope of the invention to arrange the bars in the arrays at angles to each other to produce angle members (FIG. 8); channel members (FIG. 9) eye members (FIG. and arcuately or around a common axis to produce solid rods (FIG. 11) and hollow cylinders or sections (FIG. 12).

As thus far described while the strip being formed is continuous the reciprocation of the bars makes delivery of the strip intermittent. To provide for continuous delivery of the strip the press, as indicated in FIG. 13, is reciprocably mounted in a supporting frame comprising a lower frame member 40 and an upper frame member 42 rigidly joined to each other in vertically spaced relation by shouldered tie rods 44, the frame members collectively defining a tunnel within which the press is slidingly mounted for reciprocal movement within roller bearings 48 at the top and bottom and roller bearings 50 at the sides. Reciprocal movement of the press can be provided by a cylinder and piston assembly S4 and linkage 56 connecting the piston to the press or a cam-actuated linkage and since the press is reciprocated the source of supply, by means of which the material to be compressed is deposited on the press platen, is provided with a suitable flexible mounting to enable it to follow the reciprocable movement of the press. The reciprocal movement of the press to provide for continuous delivery is synchronized with the movement of the bars so that on the forward movement of the bars the entire press is moved toward the left and on the rearward movement of the bars the entire press is moved toward the right. The stroke of the reciprocal movement of the press would, of course, correspond to the stroke of the bars.

The continuous movement of the strip material enables secondary operations as it is delivered from the press such as laminating, or finishing which is desirably carried out in the same production line.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents falling within the scope of the appended claims.

I claim:

1. A press for compacting and integrating material to form continuous flat sheets comprising spaced parallel arrays of long narrow bars, means supporting the arrays for relative movement toward each other and for supporting the bars in each array for reciprocal movement, means for supplying the material to the space between the arrays of bars at one end of the press, means for applying a predetermined constant uniform pressure perpendicular to the arrays of bars so as to apply a uniformly constant pressure transversely of the material introduced between the bars, means for advancing the bars individually in a predetermined sequence in sliding compressive engagement with the material in the direction opposite to the direction of movement of the material into the press, means for retracting all of the bars in consonance to withdraw the strip from the press and means for urging the bars in the arrays of bars toward each other through reciprocal movement of the bars.

2. Apparatus according to claim 1, wherein said reciprocal movement of the bars is a fractional part of the length of the bars and there is means for effecting repeated reciprocation of the bars to continuously draw material into the press at one end and discharge the strip from the other end.

3. A press for compacting and integrating material to form a continuous strip comprising spaced parallel arrays of long narrow bars, means supporting the bars in each array for reciprocal movement, means for supplying the material to the space between the arrays of bars at one end of the press, and means for effecting longitudinal movement of the bars in sliding compressive engagement with the material in a predetermined succession in which less than all of the bars are advanced at any one time in said direction and for retracting all of the bars in consonance in the other direction.

4. A press according to claim 3, means for advancing the bars in a direction opposite to the direction of movement of the material into the press and retracting the bars in a direction to withdraw the formed strip from the press.

5. Apparatus according to claim 3, comprising a supporting frame, means supporting the press in the supporting frame for longitudinal reciprocal movement, and means for effecting reciprocal movement of the press in such relation to the movement of the bars that the press is moving in a direction opposite to that of the bars.

6. Apparatus according to claim 3, comprising a supporting frame, means supporting the press in the supporting frame for longitudinal reciprocal movement, a reciprocable motor, means connecting the motor to the press, and means operable to initiate operation of the motor in timed relation to the reciprocation of the bars such that movement of the bars in the direction of application of pressure to the material is accompanied by movement of the press in the opposite direction.

7. A press for compacting and integrating material to form a continuous strip comprising spaced parallel platens, long narrow bars arranged side by side at the confronting sides of the platens defining a space of predetermined width therebetween, means for supplying the material to the space between the bars at one end of the press, means for advancing the bars independently of the platens in a predetermined sequence in sliding engagement with the material in which less than the entire number of bars are advanced at one time until all of the bars are advanced and means for retracting the entire number of bars in consonance.

8. A press according to claim 7, means for advancing the bars in a direction opposite to the direction of movement of the material into the press and retracting the bars in a direction to withdraw the compacted strip from the press.

9. A press for compacting and integrating material to form a continuous structure of a predetermined cross section comprising spaced parallel platens, means supporting the platens for relative movement toward each other, long narrow bars mounted at the confronting sides of the platens for reciprocal movement longitudinally thereof, the bars in each array being movable individually relative to each other, means for supplying material to the space between the bars at one end of the press, means for advancing the bars individually in a predetermined sequence in sliding compressive engagement with the material until all of the bars are advanced and means for retracting all of the bars a corresponding amount in consonance while still in compressive engagement with the formed structure to withdraw the structure from the press as it is formed.

10. A press for compacting and integrating material to form a continuous strip comprising spaced parallel platens, means for supporting the platens for relative movement toward each other, means for effecting movement of the platens toward each other, antifriction means at the confronting sides of the platens,

long narrow bars supported against the anti-friction means in confronting relation to each other with a predetermined space therebetween, for reciprocal movement longitudinally of the platens, means for supplying material to a space between the arrays of platens, means for advancing the bars individually in a predetermined sequence in which less than the entire number of bars are moved at one time, in sliding compressive engagement with the material and means for retracting all of the bars in consonance while still in compressive engagement with the material progressively to with draw the strip from the press as it is formed.

11. A press according to claim 10, wherein the antifriction means comprise lengths of antifriction material secured to the confronting faces of the platens.

12. A press according to claim 10, wherein the antifriction means comprise roller bearings supported against the confronting sides of the platens.

13. Apparatus for continuously producing continuous strip comprising spaced parallel arrays of longitudinal extending narrow bars arranged side by side transversely of the apparatus between which is adapted to be introduced material to be formed into continuous strip, means for applying a predetermined continuous pres sure perpendicular to the arrays of bars such that the material of which the strip is comprised is subjected to a constant continuous pressure as it progresses through the apparatus, means for successively advancing the bars in sliding engagement with the material longitudinal of the apparatus until all of the bars have been moved so that there is an insufficient frictional force developed by movement of any bar to displace the material in the direction of advance of the bars and means for thereafter withdrawing all of the bars in unison.

14. In an apparatus for continuously producing continuous strip, a press assembly comprising a rigid frame, spaced parallel arrays of longitudinal extending narrow bars arranged side by side transversely of the frame between which is adapted to be introduced material to be formed into a strip, means for applying a predetermined continuous uniform pressure perpendicular to the arrays of the bars such that the entire width of the material of which the strip is comprised is subjected to a constant uniform continuous pressure transversely thereof as it progresses through the press, means connected to an end of each bar for moving the bar and means operating to effect reciprocal movement of the bars forwardly a predetermined distance longitudinally of the press opposite to the progress of the material through the press and rearwardly to effect discharge of the formed strip said means effecting sequential movement of individual bars representing less than half of the total surface area forwardly until all of the bars are advanced and thereafter rearwardly in unison, means supporting the frame mounting the bars for reciprocation and means for effecting reciprocation of the bars and the frame in opposite directions such that forward movement of the bars is accompanied by rearward movement of the press assembly.

15. A press for compacting and integrating material to form a continuous strip comprising spaced parallel platens, means supporting the platens for relative movement toward each other, rams arranged to effect such relative movement, long narrow bars arranged side-by-side on the confronting faces of the platens for reciprocal movement longitudinally thereof, means for supplying material to the space between the bars, a ram connected to each bar for effecting movement thereof independently of every other bar, and control means operable to effect advance movement of the bars in a predetermined sequence and for retracting all of the bars in consonance.

Claims

10. A press for compacting and integrating material to form a continuous strip comprising spaced parallel platens, means for supporting the platens for relative movement toward each other, means for effecting movement of the platens toward each other, anti-friction means at the confronting sides of the platens, long narrow bars supported against the anti-friction means in confronting relation to each other with a predetermined space therebetween, for reciprocal movement longitudinally of the platens, means for supplying material to a space between the arrays of platens, means for advancing the bars individually in a predetermined sequence in which less than the entire number of bars are moved at one time, in sliding compressive engagement with the material and means for retracting all of the bars in consonance while still in compressive engagement with the material progressively to withdraw the strip from the press as it is formed.

11. A press according to claim 10, wherein the anti-friction means comprise lengths of antifriction material secured to the confronting faces of the platens.

12. A press according to claim 10, wherein the anti-friction means comprise roller bearings supported against the confronting sides of the platens.

13. Apparatus for continuously producing continuous strip comprising spaced parallel arrays of longitudinal extending narrow bars arranged side by side transversely of the apparatus between which is adapted to be introduced material to be formed into continuous strip, means for applying a predetermined continuous pressure perpendicular to the arrays of bars such that the material of which the strip is comprised is subjected to a constant continuous pressure as it progresses through the apparatus, means for successively advancing the bars in sliding engagement with the material longitudinal of the apparatus until all of the bars have been moved so that there is an insufficient frictional force developed by movement of any bar to displace the material in the direction of advance of the bars and means for thereafter withdrawing all of the bars in unison.