US3545370A - Continuous press for laminating materials - Google Patents

Description

United States atent [72] Inventor Robert A. Caughey Antrim, New Hampshire [21] Appl. No. 741,755

[22] Filed July 1, 1968 [45] Patented Dec. 8, 1970 [73] Assignee Weyerhaeuser Company Tacoma, Wash.

a corporation of Washington [54] CONTINUOUS PRESS FOR LAMINATING Primary Examiner-Edward L. Roberts Attorneys-Leslie G. Noller, John M. Crawford and Kenneth W. Vernon ABSTRACT: An improved continuous press for the manufacture of laminated wood materials and other wood products which has a lower platen consisting of a number of contiguous, unconnected rigid members and an upper platen parallel to but spaced from the lower platen consisting of an endless belt driven solely by transmission of force to it from the lower platens through the material fed between the two platens. The upper surface of the upper platen is in sliding contact with a series of keyed-together plates, each of the keyed-together plates having separate hydraulic rams acting downwardly on each plate to furnish the required pressure necessary to laminate or consolidate the materials fed into the press. The

lower, unconnected platen members are driven by a series of hydraulically operated driving pinions located along each side of the press and engageable with gear racks on the underside of the unconnected platen membens. The driving pinions are spaced a distance apart less than the length of the individual, unconnected platen members. The unconnected platen members are returned from the outfeed end of the conveyor to the infeed end by means of a hydraulically operated elevator which lowers each of the plates at the outfeed end onto a conveying chain running in a direction opposite the travel of the press. The conveying chain returns the platen member to the infeed end where it is raised into operating position. A hydraulically operated crowder advances it into contact with the first set of driving pinions which advance it into the press. Switches or other sensing devices are used to coordinate operation of the elevating and crowding mechanisms.

PATENTED DEC 8 I970 sum 2 BF 3 MJM PATENTED DEC 8 I976 SHEET 3 [IF 3 owns BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a continuous press for laminating wood and wood products, and consolidating wood fibrous materials.

2. Prior Art Relating to the Disclosure Presses have been developed for the continuous laminating of wood and wood products. For example, see US. Pat. Nos. 2,729,584; 2,919,732; 2,988,120; and 3,036,967. Development of a press suited for continuous efficient operation and low maintenance, however, has remained a problem.

A continuous press for the manufacture of wood particles bonded together by thermosetting resins (particleboard) is disclosed in US. Pat. No. 3,044,111. This press comprises a stationary lower platen and an upper platen defining a passage for the material therebetween. Over the lower platen is located a series of contiguous, unconnected plates in sliding relation with the lower platen, the plates driven by a single hydraulic ram at the infeed end of the press. Over the upper platen is trained a continuous belt in sliding contact with the upper platen, the belt driven through the press solely by frictional engagement of the belt with the material in contact with the lower platen members being driven through the press. The

press described has inherent limitations as to size and pressure when used in the lamination of wood and wood products. For example, the method described in the above-mentioned patent for advancing the contiguous, unconnected platen members through the press by means of a single hydraulic ram is unsuited to commercial production because of the heavy stresses imposed on the means to advance the plates through the press, particularly when high pressures are used.

SUMMARY OF THE INVENTION This invention relates to an improved press of the type described in U.S. Pat. No. 3,044,1 1 1. In general, the improved press of this invention comprises a series of contiguous, unconnected rigid platen members resting on a rigid supporting bearing surface, the platen members forming a lower platen for the press, and an upper platen disposed above the lower platen and substantially parallel thereto, the upper platen consisting of a continuous, movable belt sliding directly on a lubricated, low friction surface. The low friction surface consists of a series of short plates keyed together with each plate having a separate hydraulic rain acting downwardly thereon so as to provide requisite pressure necessary for laminating materials together. The lower, unconnected platens are driven through the press by a plurality of power means spaced adjacent each of the lower platen members and engageable therewith, each of the power means spaced a distance less than the length of the individual unconnected platen members. The power means generally comprises a series of hydraulically operated motors which drive driving pinions located on each side of the press, the pinions engageable with gear racks located on the under surface of the contiguous, unconnected, rigid platen members. By using 'a multidrive system, the total force required for advancing the lower platen members through the press is distributed equally among the driving pinions, avoiding overloading of the pinions and alleviating severe operational problems.

The contiguous, unconnected, lower platen members are returned from the outfeed end of the press to the infeed end by the combination of a hydraulically operated mechanism which lowers the individual platens out of contact with the material being fed through the press as an exit from the outfeed end of the press onto a conveyor chain which moves the members to the infeed end of the press. At the infeed end a similar hydraulically operated elevating means lifts the platen members to its normal operating position in contact with the material being pressed. A hydraulically operated crowding means located at the infeed end of the press and at the same level as the platens being driven through the press engages the raised platen member and advances it into abutting relationship with the preceeding platen and subsequently into engagement with the first set of driving pinions of the multidrive system for movement through the press. Sensing means comprising switches, photo cells, or other means are used to coordinate lowering, raising and crowding of the unconnected platen members in conjunction with operation of the press.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A is a side elevation of the entry or infeed end of the improved press with parts broken away for better illustration.

FIG. 1B is a side elevation of the exit or outfeed end of the improved press.

FIG. 2 is a view along section line 2-2 of FIG. 1A.

FIG. 3 is a view along section line 33 of FIG. IA.

FIG. 4 is a view along section line 4-4 of FIG. 1B.

DETAILED DESCRIPTION OF THE DRAWINGS The various parts of the machine are shown in FIGS. 1A and 1B and are mounted on a frame consisting of a pair of side members 1 and 2. Each of the side members comprises a lower portion and an upper portion, the two connected together by stress rods 3 which are adjustable. A bearing member 4 is permanently fixed between side panels I and 2 in any convenient manner. The top surface of member 4 is preferably highly polished to reduce friction. Resting on bearing member 4 and in sliding contact therewith are a series of rectangular, contiguous, unconnected platens 5 which form the lower platen of the press. These platens travelthrough the press from the infeed end to the exit end thereof in contiguous, unconnected relation and slide freely between members 1 and 2 and on bearing member 4.

The series of platens 5 are moved through the press by pairs of individually hydraulically driven driving pinions 6 located on each side of the press and preferably spaced at distance apart less than the length of the individual unconnected platens 5. Driving pinions 6 engage gear racks 7 located on the undersurface of each of the platens 5. A suitable power source such as individual hydraulic motors 8 are connected to each of the driving pinions 6 by means of sprockets 9 and 10 connected together by chains 11. Drive shafts l2 connect each of the hydraulic motor pairs located on each side of the press in order to synchronize their operation. The platens 5 can be,

moved through the press equally as well by other means. For example, the pinions 6 can be on a common Although the although the drawings indicate driving pinions extending the full length of the press, there is usually no need to extend them to the discharge end. The spacing of the motors and driving pinions is a function of platen loading which, at the discharge end of the press, is not significant.

This multipoint drive system distributes the total force required for advancing the series of platens 5 through the press equally among the driving pinions so that no pinion is overloaded. Without the multiple drive system severe limitations would be placed on the press with respect to maximum size and pressure. For example, assuming a press 12% wide and 24 long, a pressure on the workpiece of 200 p.s.i., and an overall coefficient of friction on 0.1, the total driving force required for forcing the series of platens therethrough would be approximately 72,000 lbs. A two pinion drive would, of necessity, have to pull approximately 36,000 lbs., necessitating special large gears, shafts and motors. In the improved press of this invention the total load is shared. Using the same example, if 24 2-inch diameter gears are used, each pinion would be torqued to 3,000 pound inches which is well within limit of standard gears and motors.

The upper platen 13 consists of a continuous, steel belt or belt of other suitable metal. The upper belt serves only as a continuous bearing and is moved by the product being pressed. It is not under severe tension, and guiding and band tracking problems are substantially reduced. The band is trained around a circular surface 14 at the exit end of the press and follows along the top of the press 15 and 16 in returning to the infeed end. Pressure is exerted on belt or upper platen 13 by a series of short plates 17 keyed together at 18. A series of hydraulic rams 19 connected to the supporting frame have their pistons attached to each individual plate 17. Plates 17 are in sliding contact with belt 13. A suitable lubricant may be injected by injecting means 17', shown schematically in FIG. 3, between belt 13 and plates 17 to minimize friction therebetween. By having separate, though interconnected, upper pressure plates, a pressure profile through the press is possible, allowing optimum pressure conditions for the particular product desired. For example, the press can be operated so as to have a high initial pressure followed by decreasing pressure; a gradually increasing, then decreasing pressure; or a gradually increasing pressure. This pressure flexibility enables manufacture of specialty products where closely controlled conditions are needed.

The individual, unconnected platens 5, when they reach the exit end of the press, are returned to the infeed end by an improved conveying mechanism which lowers the individual platens at the outfeed end of the press, conveys them to the infeed end of the press, raises them to operating height and in line with a hydraulic crowder which crowds the platen into contact with the next adjacent platen and into driving engagement with the first set of driving pinions at the infeed end of the press. The mechanism to lower each of the unconnected platens at the outfeed end of the press comprises a hydraulically operated table 20 which, in raised position, is in line with the path of platens 5 through the press. A hydraulic cylinder 21 operates table 20. A control device 20 is positioned so as to actuate lowering of table 20 when one of the platens 5 is resting thereon. Hydraulic cylinder 21 lowers table 20 and the platen plate 5 to the level of conveyor chains 22 trained around sprockets 23. The return conveyor may have a nylon bearing surface so that platens 5 are not damaged during their conveyance from the outfeed to the infeed end of the conveyor. When one of the platens 5 reaches the infeed end of the press another hydraulic cylinder 24 attached to table 25 is actuated by a suitable control device 24. When platen 5 is positioned over table 25, the table raises the platen 5 in the path of crowder member 26 and in position for entry into the press. Crowder member 26 is attached to another hydraulic cylinder 27 which is actuated by control device 27 as soon as platen 5 is raised to the proper position. The crowder member advances platen 5 into engagement with the first set of driving pinions 6 at the infeed end of the press and into contiguous relationship with the next adjacent platen 5. The operation of cylinders 21,24, and 27 is synchronized by suitable control devices 21,24' and 27' so that the lowering, raising, and crowding functions are performed in relation to overall operation of the press.

In operation sheets of wood veneer 28 or other material are fed into the infeed end of the press. In the case of wood veneer, it is usually preheated and coated with a suitable thermosetting adhesive for bonding the wood laminae together. The laminae are then brought into contact as they approach the nip end of the press. The length and width of the press can be adjusted to suit purposes desired. As the laminae enter the press they are compressed to such a degree that the internal friction between the laminae greatly exceeds the friction between belt 13 and plates 17 and also the friction between the laminae and belt 13. This permits the transmission from the moving series of platens 5 to the belt 13 of a force sufficient to advance belt 13 through the press.

Many laminated products can be made using the improved press of this invention. Wood products overlayed with plastic or fibrous material mixed with suitable thermosetting resins can also be laminated.

Iclaim:

I. An improved press for manufacturing composite or laminated wood materials comprising:

a supporting frame having thereon a substantially horizontal, rigid, supporting bearing surface;

a plur ity of contiguous, unconnected, rigid platen members forming a continuous lower platen resting on said bearing surface and movable from an infeed end to an outfeed end;

a continuous, movable belt having an undersurface disposed in spaced relation to the lower platen and defining a passageway, the belt adapted to be driven solely by forces transmitted to it from the lower platen through the material as it is fed between the lower platen and belt;

pressure means operable directly against the upper surface of the lower 'run of the belt and in a downward direction toward the lower platen; and

means for driving the lower, unconnected platen members comprising a plurality of power means spaced adjacent the platen members and engageable therewith individually to distribute the driving load along the path of said platen members.

2. Apparatus according to claim 1 wherein each of the unconnected, rigid platen members has gear racks located on its undersurface and wherein the power means comprises a series of driving pinions engageable with the gear racks on the unconnected, rigid platen members.

3. Apparatus according to claim 1 wherein the power means are spaced a distance apart less than the length of the individual, unconnected platen members.

4. Apparatus according to claim 2 wherein the driving pinions are hydraulically operated.

5. Apparatus according to claim 1 wherein the pressure means includes a plurality of separate plates in slidable contact with the belt and a plurality of hydraulic rams acting downwardly on each plate.

6. Apparatus according to claim 5 wherein the plates linked together.

7. Apparatus according to claim 5 including means for injecting a lubricant between the plates in a slidable contact with the belt and the belt.

8. An improved press for manufacturing composite or laminated wood materials comprising:

a supporting frame having thereon a substantially horizontal, rigid supporting bearing surface;

a plurality of contiguous, unconnecting, rigid platen members forming a continuous lower platen on said bearing surface and movable from an infeed end to an outfeed end;

a continuous, movable belt having an undersurface disposed in spaced relation to the lower platen and adapted to be driven by the force transmitted to it from the lower platen through the material fed between the lower platen and upper belt;

pressure means operable against the upper surface of the lower run of the belt and in a downward direction toward the lower platen;

means for driving the individual lower platen members; and

means for returning the unconnected platen members from the outfeed end of the press to the infeed end comprising:

a. lowering means to individually and separately lower each of the unconnected members out of contact with the material fed into the press at the outfeed end thereof;

b. conveying means to convey the platen members from the outfeed end to the infeed end of the press;

c. elevating means to individually and separately elevate each of the unconnected platen members to its operating position in contact with the material being pressed,

d. crowding means located at the infeed end of the press and in line with the platen member to push the member into engagement with the first set of driving pinions at the infeed end of the press and into contiguous relations with the next adjacent platen member; and

e. sensing means for synchronizing lowering, raising and crowding of the platen members in coordination with operation of the press.

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zg g UNITED STATES PATENT OFFICE 4 CERTIFICATE OF CORRECTION Patent No. 3,545,370 Dated December 8, 1970 Inventor(s) ROBERT A. CAUGHEY It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In column 2, line 48, "common Although the" should read --common shaft.--;

in column 2, line 49, "although" should read -Although--.

Signed and sealed this 11th day of May". 1971.

(SEAL) Attest:

EBMRDMJLETQPIERQ R. WILLIAM E. SCHUYLER, JR. Attest g Off cer Commissioner of Patents

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